diff options
Diffstat (limited to 'fs/btrfs/tree-log.c')
| -rw-r--r-- | fs/btrfs/tree-log.c | 8201 |
1 files changed, 8201 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c new file mode 100644 index 000000000..7ba7b6098 --- /dev/null +++ b/fs/btrfs/tree-log.c @@ -0,0 +1,8201 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2008 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/blkdev.h> +#include <linux/list_sort.h> +#include <linux/iversion.h> +#include "misc.h" +#include "ctree.h" +#include "tree-log.h" +#include "disk-io.h" +#include "locking.h" +#include "backref.h" +#include "compression.h" +#include "qgroup.h" +#include "block-group.h" +#include "space-info.h" +#include "inode-item.h" +#include "fs.h" +#include "accessors.h" +#include "extent-tree.h" +#include "root-tree.h" +#include "dir-item.h" +#include "file-item.h" +#include "file.h" +#include "orphan.h" +#include "print-tree.h" +#include "tree-checker.h" +#include "delayed-inode.h" + +#define MAX_CONFLICT_INODES 10 + +/* + * directory trouble cases + * + * 1) on rename or unlink, if the inode being unlinked isn't in the fsync + * log, we must force a full commit before doing an fsync of the directory + * where the unlink was done. + * ---> record transid of last unlink/rename per directory + * + * mkdir foo/some_dir + * normal commit + * rename foo/some_dir foo2/some_dir + * mkdir foo/some_dir + * fsync foo/some_dir/some_file + * + * The fsync above will unlink the original some_dir without recording + * it in its new location (foo2). After a crash, some_dir will be gone + * unless the fsync of some_file forces a full commit + * + * 2) we must log any new names for any file or dir that is in the fsync + * log. ---> check inode while renaming/linking. + * + * 2a) we must log any new names for any file or dir during rename + * when the directory they are being removed from was logged. + * ---> check inode and old parent dir during rename + * + * 2a is actually the more important variant. With the extra logging + * a crash might unlink the old name without recreating the new one + * + * 3) after a crash, we must go through any directories with a link count + * of zero and redo the rm -rf + * + * mkdir f1/foo + * normal commit + * rm -rf f1/foo + * fsync(f1) + * + * The directory f1 was fully removed from the FS, but fsync was never + * called on f1, only its parent dir. After a crash the rm -rf must + * be replayed. This must be able to recurse down the entire + * directory tree. The inode link count fixup code takes care of the + * ugly details. + */ + +/* + * stages for the tree walking. The first + * stage (0) is to only pin down the blocks we find + * the second stage (1) is to make sure that all the inodes + * we find in the log are created in the subvolume. + * + * The last stage is to deal with directories and links and extents + * and all the other fun semantics + */ +enum { + LOG_WALK_PIN_ONLY, + LOG_WALK_REPLAY_INODES, + LOG_WALK_REPLAY_DIR_INDEX, + LOG_WALK_REPLAY_ALL, +}; + +/* + * The walk control struct is used to pass state down the chain when processing + * the log tree. The stage field tells us which part of the log tree processing + * we are currently doing. + */ +struct walk_control { + /* + * Signal that we are freeing the metadata extents of a log tree. + * This is used at transaction commit time while freeing a log tree. + */ + bool free; + + /* + * Signal that we are pinning the metadata extents of a log tree and the + * data extents its leaves point to (if using mixed block groups). + * This happens in the first stage of log replay to ensure that during + * replay, while we are modifying subvolume trees, we don't overwrite + * the metadata extents of log trees. + */ + bool pin; + + /* What stage of the replay code we're currently in. */ + int stage; + + /* + * Ignore any items from the inode currently being processed. Needs + * to be set every time we find a BTRFS_INODE_ITEM_KEY. + */ + bool ignore_cur_inode; + + /* + * The root we are currently replaying to. This is NULL for the replay + * stage LOG_WALK_PIN_ONLY. + */ + struct btrfs_root *root; + + /* The log tree we are currently processing (not NULL for any stage). */ + struct btrfs_root *log; + + /* The transaction handle used for replaying all log trees. */ + struct btrfs_trans_handle *trans; + + /* + * The function that gets used to process blocks we find in the tree. + * Note the extent_buffer might not be up to date when it is passed in, + * and it must be checked or read if you need the data inside it. + */ + int (*process_func)(struct extent_buffer *eb, + struct walk_control *wc, u64 gen, int level); + + /* + * The following are used only when stage is >= LOG_WALK_REPLAY_INODES + * and by the replay_one_buffer() callback. + */ + + /* The current log leaf being processed. */ + struct extent_buffer *log_leaf; + /* The key being processed of the current log leaf. */ + struct btrfs_key log_key; + /* The slot being processed of the current log leaf. */ + int log_slot; + + /* A path used for searches and modifications to subvolume trees. */ + struct btrfs_path *subvol_path; +}; + +static void do_abort_log_replay(struct walk_control *wc, const char *function, + unsigned int line, int error, const char *fmt, ...) +{ + struct btrfs_fs_info *fs_info = wc->trans->fs_info; + struct va_format vaf; + va_list args; + + /* + * Do nothing if we already aborted, to avoid dumping leaves again which + * can be verbose. Further more, only the first call is useful since it + * is where we have a problem. Note that we do not use the flag + * BTRFS_FS_STATE_TRANS_ABORTED because log replay calls functions that + * are outside of tree-log.c that can abort transactions (such as + * btrfs_add_link() for example), so if that happens we still want to + * dump all log replay specific information below. + */ + if (test_and_set_bit(BTRFS_FS_STATE_LOG_REPLAY_ABORTED, &fs_info->fs_state)) + return; + + btrfs_abort_transaction(wc->trans, error); + + if (wc->subvol_path && wc->subvol_path->nodes[0]) { + btrfs_crit(fs_info, + "subvolume (root %llu) leaf currently being processed:", + btrfs_root_id(wc->root)); + btrfs_print_leaf(wc->subvol_path->nodes[0]); + } + + if (wc->log_leaf) { + btrfs_crit(fs_info, +"log tree (for root %llu) leaf currently being processed (slot %d key " BTRFS_KEY_FMT "):", + btrfs_root_id(wc->root), wc->log_slot, + BTRFS_KEY_FMT_VALUE(&wc->log_key)); + btrfs_print_leaf(wc->log_leaf); + } + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + btrfs_crit(fs_info, + "log replay failed in %s:%u for root %llu, stage %d, with error %d: %pV", + function, line, btrfs_root_id(wc->root), wc->stage, error, &vaf); + + va_end(args); +} + +/* + * Use this for aborting a transaction during log replay while we are down the + * call chain of replay_one_buffer(), so that we get a lot more useful + * information for debugging issues when compared to a plain call to + * btrfs_abort_transaction(). + */ +#define btrfs_abort_log_replay(wc, error, fmt, args...) \ + do_abort_log_replay((wc), __func__, __LINE__, (error), fmt, ##args) + +static int btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + enum btrfs_log_mode log_mode, + struct btrfs_log_ctx *ctx); +static int link_to_fixup_dir(struct walk_control *wc, u64 objectid); +static noinline int replay_dir_deletes(struct walk_control *wc, + u64 dirid, bool del_all); +static bool wait_log_commit(struct btrfs_root *root, int transid); + +/* + * tree logging is a special write ahead log used to make sure that + * fsyncs and O_SYNCs can happen without doing full tree commits. + * + * Full tree commits are expensive because they require commonly + * modified blocks to be recowed, creating many dirty pages in the + * extent tree an 4x-6x higher write load than ext3. + * + * Instead of doing a tree commit on every fsync, we use the + * key ranges and transaction ids to find items for a given file or directory + * that have changed in this transaction. Those items are copied into + * a special tree (one per subvolume root), that tree is written to disk + * and then the fsync is considered complete. + * + * After a crash, items are copied out of the log-tree back into the + * subvolume tree. Any file data extents found are recorded in the extent + * allocation tree, and the log-tree freed. + * + * The log tree is read three times, once to pin down all the extents it is + * using in ram and once, once to create all the inodes logged in the tree + * and once to do all the other items. + */ + +static struct btrfs_inode *btrfs_iget_logging(u64 objectid, struct btrfs_root *root) +{ + unsigned int nofs_flag; + struct btrfs_inode *inode; + + /* Only meant to be called for subvolume roots and not for log roots. */ + ASSERT(btrfs_is_fstree(btrfs_root_id(root)), "root_id=%llu", btrfs_root_id(root)); + + /* + * We're holding a transaction handle whether we are logging or + * replaying a log tree, so we must make sure NOFS semantics apply + * because btrfs_alloc_inode() may be triggered and it uses GFP_KERNEL + * to allocate an inode, which can recurse back into the filesystem and + * attempt a transaction commit, resulting in a deadlock. + */ + nofs_flag = memalloc_nofs_save(); + inode = btrfs_iget(objectid, root); + memalloc_nofs_restore(nofs_flag); + + return inode; +} + +/* + * start a sub transaction and setup the log tree + * this increments the log tree writer count to make the people + * syncing the tree wait for us to finish + */ +static int start_log_trans(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *tree_root = fs_info->tree_root; + const bool zoned = btrfs_is_zoned(fs_info); + int ret = 0; + bool created = false; + + /* + * First check if the log root tree was already created. If not, create + * it before locking the root's log_mutex, just to keep lockdep happy. + */ + if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) { + mutex_lock(&tree_root->log_mutex); + if (!fs_info->log_root_tree) { + ret = btrfs_init_log_root_tree(trans, fs_info); + if (!ret) { + set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state); + created = true; + } + } + mutex_unlock(&tree_root->log_mutex); + if (ret) + return ret; + } + + mutex_lock(&root->log_mutex); + +again: + if (root->log_root) { + if (btrfs_need_log_full_commit(trans)) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + if (zoned && wait_log_commit(root, root->log_transid - 1)) + goto again; + } else { + /* + * This means fs_info->log_root_tree was already created + * for some other FS trees. Do the full commit not to mix + * nodes from multiple log transactions to do sequential + * writing. + */ + if (zoned && !created) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + ret = btrfs_add_log_tree(trans, root); + if (ret) + goto out; + + set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); + } + + atomic_inc(&root->log_writers); + if (!ctx->logging_new_name) { + int index = root->log_transid % 2; + list_add_tail(&ctx->list, &root->log_ctxs[index]); + ctx->log_transid = root->log_transid; + } + +out: + mutex_unlock(&root->log_mutex); + return ret; +} + +/* + * returns 0 if there was a log transaction running and we were able + * to join, or returns -ENOENT if there were not transactions + * in progress + */ +static int join_running_log_trans(struct btrfs_root *root) +{ + const bool zoned = btrfs_is_zoned(root->fs_info); + int ret = -ENOENT; + + if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state)) + return ret; + + mutex_lock(&root->log_mutex); +again: + if (root->log_root) { + ret = 0; + if (zoned && wait_log_commit(root, root->log_transid - 1)) + goto again; + atomic_inc(&root->log_writers); + } + mutex_unlock(&root->log_mutex); + return ret; +} + +/* + * This either makes the current running log transaction wait + * until you call btrfs_end_log_trans() or it makes any future + * log transactions wait until you call btrfs_end_log_trans() + */ +void btrfs_pin_log_trans(struct btrfs_root *root) +{ + atomic_inc(&root->log_writers); +} + +/* + * indicate we're done making changes to the log tree + * and wake up anyone waiting to do a sync + */ +void btrfs_end_log_trans(struct btrfs_root *root) +{ + if (atomic_dec_and_test(&root->log_writers)) { + /* atomic_dec_and_test implies a barrier */ + cond_wake_up_nomb(&root->log_writer_wait); + } +} + +/* + * process_func used to pin down extents, write them or wait on them + */ +static int process_one_buffer(struct extent_buffer *eb, + struct walk_control *wc, u64 gen, int level) +{ + struct btrfs_root *log = wc->log; + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_fs_info *fs_info = log->fs_info; + int ret = 0; + + /* + * If this fs is mixed then we need to be able to process the leaves to + * pin down any logged extents, so we have to read the block. + */ + if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) { + struct btrfs_tree_parent_check check = { + .level = level, + .transid = gen + }; + + ret = btrfs_read_extent_buffer(eb, &check); + if (unlikely(ret)) { + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(fs_info, ret, NULL); + return ret; + } + } + + if (wc->pin) { + ASSERT(trans != NULL); + ret = btrfs_pin_extent_for_log_replay(trans, eb); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + return ret; + } + + if (btrfs_buffer_uptodate(eb, gen, NULL) && level == 0) { + ret = btrfs_exclude_logged_extents(eb); + if (ret) + btrfs_abort_transaction(trans, ret); + } + } + return ret; +} + +/* + * Item overwrite used by log replay. The given log tree leaf, slot and key + * from the walk_control structure all refer to the source data we are copying + * out. + * + * The given root is for the tree we are copying into, and path is a scratch + * path for use in this function (it should be released on entry and will be + * released on exit). + * + * If the key is already in the destination tree the existing item is + * overwritten. If the existing item isn't big enough, it is extended. + * If it is too large, it is truncated. + * + * If the key isn't in the destination yet, a new item is inserted. + */ +static int overwrite_item(struct walk_control *wc) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + int ret; + u32 item_size; + u64 saved_i_size = 0; + int save_old_i_size = 0; + unsigned long src_ptr; + unsigned long dst_ptr; + struct extent_buffer *dst_eb; + int dst_slot; + const bool is_inode_item = (wc->log_key.type == BTRFS_INODE_ITEM_KEY); + + /* + * This is only used during log replay, so the root is always from a + * fs/subvolume tree. In case we ever need to support a log root, then + * we'll have to clone the leaf in the path, release the path and use + * the leaf before writing into the log tree. See the comments at + * copy_items() for more details. + */ + ASSERT(btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID); + + item_size = btrfs_item_size(wc->log_leaf, wc->log_slot); + src_ptr = btrfs_item_ptr_offset(wc->log_leaf, wc->log_slot); + + /* Look for the key in the destination tree. */ + ret = btrfs_search_slot(NULL, root, &wc->log_key, wc->subvol_path, 0, 0); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to search subvolume tree for key " BTRFS_KEY_FMT " root %llu", + BTRFS_KEY_FMT_VALUE(&wc->log_key), + btrfs_root_id(root)); + return ret; + } + + dst_eb = wc->subvol_path->nodes[0]; + dst_slot = wc->subvol_path->slots[0]; + + if (ret == 0) { + char *src_copy; + const u32 dst_size = btrfs_item_size(dst_eb, dst_slot); + + if (dst_size != item_size) + goto insert; + + if (item_size == 0) { + btrfs_release_path(wc->subvol_path); + return 0; + } + src_copy = kmalloc(item_size, GFP_NOFS); + if (!src_copy) { + btrfs_abort_log_replay(wc, -ENOMEM, + "failed to allocate memory for log leaf item"); + return -ENOMEM; + } + + read_extent_buffer(wc->log_leaf, src_copy, src_ptr, item_size); + dst_ptr = btrfs_item_ptr_offset(dst_eb, dst_slot); + ret = memcmp_extent_buffer(dst_eb, src_copy, dst_ptr, item_size); + + kfree(src_copy); + /* + * they have the same contents, just return, this saves + * us from cowing blocks in the destination tree and doing + * extra writes that may not have been done by a previous + * sync + */ + if (ret == 0) { + btrfs_release_path(wc->subvol_path); + return 0; + } + + /* + * We need to load the old nbytes into the inode so when we + * replay the extents we've logged we get the right nbytes. + */ + if (is_inode_item) { + struct btrfs_inode_item *item; + u64 nbytes; + u32 mode; + + item = btrfs_item_ptr(dst_eb, dst_slot, + struct btrfs_inode_item); + nbytes = btrfs_inode_nbytes(dst_eb, item); + item = btrfs_item_ptr(wc->log_leaf, wc->log_slot, + struct btrfs_inode_item); + btrfs_set_inode_nbytes(wc->log_leaf, item, nbytes); + + /* + * If this is a directory we need to reset the i_size to + * 0 so that we can set it up properly when replaying + * the rest of the items in this log. + */ + mode = btrfs_inode_mode(wc->log_leaf, item); + if (S_ISDIR(mode)) + btrfs_set_inode_size(wc->log_leaf, item, 0); + } + } else if (is_inode_item) { + struct btrfs_inode_item *item; + u32 mode; + + /* + * New inode, set nbytes to 0 so that the nbytes comes out + * properly when we replay the extents. + */ + item = btrfs_item_ptr(wc->log_leaf, wc->log_slot, struct btrfs_inode_item); + btrfs_set_inode_nbytes(wc->log_leaf, item, 0); + + /* + * If this is a directory we need to reset the i_size to 0 so + * that we can set it up properly when replaying the rest of + * the items in this log. + */ + mode = btrfs_inode_mode(wc->log_leaf, item); + if (S_ISDIR(mode)) + btrfs_set_inode_size(wc->log_leaf, item, 0); + } +insert: + btrfs_release_path(wc->subvol_path); + /* try to insert the key into the destination tree */ + wc->subvol_path->skip_release_on_error = true; + ret = btrfs_insert_empty_item(trans, root, wc->subvol_path, &wc->log_key, item_size); + wc->subvol_path->skip_release_on_error = false; + + dst_eb = wc->subvol_path->nodes[0]; + dst_slot = wc->subvol_path->slots[0]; + + /* make sure any existing item is the correct size */ + if (ret == -EEXIST || ret == -EOVERFLOW) { + const u32 found_size = btrfs_item_size(dst_eb, dst_slot); + + if (found_size > item_size) + btrfs_truncate_item(trans, wc->subvol_path, item_size, 1); + else if (found_size < item_size) + btrfs_extend_item(trans, wc->subvol_path, item_size - found_size); + } else if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to insert item for key " BTRFS_KEY_FMT, + BTRFS_KEY_FMT_VALUE(&wc->log_key)); + return ret; + } + dst_ptr = btrfs_item_ptr_offset(dst_eb, dst_slot); + + /* don't overwrite an existing inode if the generation number + * was logged as zero. This is done when the tree logging code + * is just logging an inode to make sure it exists after recovery. + * + * Also, don't overwrite i_size on directories during replay. + * log replay inserts and removes directory items based on the + * state of the tree found in the subvolume, and i_size is modified + * as it goes + */ + if (is_inode_item && ret == -EEXIST) { + struct btrfs_inode_item *src_item; + struct btrfs_inode_item *dst_item; + + src_item = (struct btrfs_inode_item *)src_ptr; + dst_item = (struct btrfs_inode_item *)dst_ptr; + + if (btrfs_inode_generation(wc->log_leaf, src_item) == 0) { + const u64 ino_size = btrfs_inode_size(wc->log_leaf, src_item); + + /* + * For regular files an ino_size == 0 is used only when + * logging that an inode exists, as part of a directory + * fsync, and the inode wasn't fsynced before. In this + * case don't set the size of the inode in the fs/subvol + * tree, otherwise we would be throwing valid data away. + */ + if (S_ISREG(btrfs_inode_mode(wc->log_leaf, src_item)) && + S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) && + ino_size != 0) + btrfs_set_inode_size(dst_eb, dst_item, ino_size); + goto no_copy; + } + + if (S_ISDIR(btrfs_inode_mode(wc->log_leaf, src_item)) && + S_ISDIR(btrfs_inode_mode(dst_eb, dst_item))) { + save_old_i_size = 1; + saved_i_size = btrfs_inode_size(dst_eb, dst_item); + } + } + + copy_extent_buffer(dst_eb, wc->log_leaf, dst_ptr, src_ptr, item_size); + + if (save_old_i_size) { + struct btrfs_inode_item *dst_item; + + dst_item = (struct btrfs_inode_item *)dst_ptr; + btrfs_set_inode_size(dst_eb, dst_item, saved_i_size); + } + + /* make sure the generation is filled in */ + if (is_inode_item) { + struct btrfs_inode_item *dst_item; + + dst_item = (struct btrfs_inode_item *)dst_ptr; + if (btrfs_inode_generation(dst_eb, dst_item) == 0) + btrfs_set_inode_generation(dst_eb, dst_item, trans->transid); + } +no_copy: + btrfs_release_path(wc->subvol_path); + return 0; +} + +static int read_alloc_one_name(struct extent_buffer *eb, void *start, int len, + struct fscrypt_str *name) +{ + char *buf; + + buf = kmalloc(len, GFP_NOFS); + if (!buf) + return -ENOMEM; + + read_extent_buffer(eb, buf, (unsigned long)start, len); + name->name = buf; + name->len = len; + return 0; +} + +/* replays a single extent in 'eb' at 'slot' with 'key' into the + * subvolume 'root'. path is released on entry and should be released + * on exit. + * + * extents in the log tree have not been allocated out of the extent + * tree yet. So, this completes the allocation, taking a reference + * as required if the extent already exists or creating a new extent + * if it isn't in the extent allocation tree yet. + * + * The extent is inserted into the file, dropping any existing extents + * from the file that overlap the new one. + */ +static noinline int replay_one_extent(struct walk_control *wc) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_drop_extents_args drop_args = { 0 }; + struct btrfs_fs_info *fs_info = root->fs_info; + int found_type; + u64 extent_end; + const u64 start = wc->log_key.offset; + u64 nbytes = 0; + u64 csum_start; + u64 csum_end; + LIST_HEAD(ordered_sums); + u64 offset; + unsigned long dest_offset; + struct btrfs_key ins; + struct btrfs_file_extent_item *item; + struct btrfs_inode *inode = NULL; + int ret = 0; + + item = btrfs_item_ptr(wc->log_leaf, wc->log_slot, struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(wc->log_leaf, item); + + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { + extent_end = start + btrfs_file_extent_num_bytes(wc->log_leaf, item); + /* Holes don't take up space. */ + if (btrfs_file_extent_disk_bytenr(wc->log_leaf, item) != 0) + nbytes = btrfs_file_extent_num_bytes(wc->log_leaf, item); + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { + nbytes = btrfs_file_extent_ram_bytes(wc->log_leaf, item); + extent_end = ALIGN(start + nbytes, fs_info->sectorsize); + } else { + btrfs_abort_log_replay(wc, -EUCLEAN, + "unexpected extent type=%d root=%llu inode=%llu offset=%llu", + found_type, btrfs_root_id(root), + wc->log_key.objectid, wc->log_key.offset); + return -EUCLEAN; + } + + inode = btrfs_iget_logging(wc->log_key.objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + btrfs_abort_log_replay(wc, ret, + "failed to get inode %llu for root %llu", + wc->log_key.objectid, btrfs_root_id(root)); + return ret; + } + + /* + * first check to see if we already have this extent in the + * file. This must be done before the btrfs_drop_extents run + * so we don't try to drop this extent. + */ + ret = btrfs_lookup_file_extent(trans, root, wc->subvol_path, + btrfs_ino(inode), start, 0); + + if (ret == 0 && + (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC)) { + struct extent_buffer *leaf = wc->subvol_path->nodes[0]; + struct btrfs_file_extent_item existing; + unsigned long ptr; + + ptr = btrfs_item_ptr_offset(leaf, wc->subvol_path->slots[0]); + read_extent_buffer(leaf, &existing, ptr, sizeof(existing)); + + /* + * we already have a pointer to this exact extent, + * we don't have to do anything + */ + if (memcmp_extent_buffer(wc->log_leaf, &existing, (unsigned long)item, + sizeof(existing)) == 0) { + btrfs_release_path(wc->subvol_path); + goto out; + } + } + btrfs_release_path(wc->subvol_path); + + /* drop any overlapping extents */ + drop_args.start = start; + drop_args.end = extent_end; + drop_args.drop_cache = true; + drop_args.path = wc->subvol_path; + ret = btrfs_drop_extents(trans, root, inode, &drop_args); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to drop extents for inode %llu range [%llu, %llu) root %llu", + wc->log_key.objectid, start, extent_end, + btrfs_root_id(root)); + goto out; + } + + if (found_type == BTRFS_FILE_EXTENT_INLINE) { + /* inline extents are easy, we just overwrite them */ + ret = overwrite_item(wc); + if (ret) + goto out; + goto update_inode; + } + + /* + * If not an inline extent, it can only be a regular or prealloc one. + * We have checked that above and returned -EUCLEAN if not. + */ + + /* A hole and NO_HOLES feature enabled, nothing else to do. */ + if (btrfs_file_extent_disk_bytenr(wc->log_leaf, item) == 0 && + btrfs_fs_incompat(fs_info, NO_HOLES)) + goto update_inode; + + ret = btrfs_insert_empty_item(trans, root, wc->subvol_path, + &wc->log_key, sizeof(*item)); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to insert item with key " BTRFS_KEY_FMT " root %llu", + BTRFS_KEY_FMT_VALUE(&wc->log_key), + btrfs_root_id(root)); + goto out; + } + dest_offset = btrfs_item_ptr_offset(wc->subvol_path->nodes[0], + wc->subvol_path->slots[0]); + copy_extent_buffer(wc->subvol_path->nodes[0], wc->log_leaf, dest_offset, + (unsigned long)item, sizeof(*item)); + + /* + * We have an explicit hole and NO_HOLES is not enabled. We have added + * the hole file extent item to the subvolume tree, so we don't have + * anything else to do other than update the file extent item range and + * update the inode item. + */ + if (btrfs_file_extent_disk_bytenr(wc->log_leaf, item) == 0) { + btrfs_release_path(wc->subvol_path); + goto update_inode; + } + + ins.objectid = btrfs_file_extent_disk_bytenr(wc->log_leaf, item); + ins.type = BTRFS_EXTENT_ITEM_KEY; + ins.offset = btrfs_file_extent_disk_num_bytes(wc->log_leaf, item); + offset = wc->log_key.offset - btrfs_file_extent_offset(wc->log_leaf, item); + + /* + * Manually record dirty extent, as here we did a shallow file extent + * item copy and skip normal backref update, but modifying extent tree + * all by ourselves. So need to manually record dirty extent for qgroup, + * as the owner of the file extent changed from log tree (doesn't affect + * qgroup) to fs/file tree (affects qgroup). + */ + ret = btrfs_qgroup_trace_extent(trans, ins.objectid, ins.offset); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to trace extent for bytenr %llu disk_num_bytes %llu inode %llu root %llu", + ins.objectid, ins.offset, + wc->log_key.objectid, btrfs_root_id(root)); + goto out; + } + + /* + * Is this extent already allocated in the extent tree? + * If so, just add a reference. + */ + ret = btrfs_lookup_data_extent(fs_info, ins.objectid, ins.offset); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to lookup data extent for bytenr %llu disk_num_bytes %llu inode %llu root %llu", + ins.objectid, ins.offset, + wc->log_key.objectid, btrfs_root_id(root)); + goto out; + } else if (ret == 0) { + struct btrfs_ref ref = { + .action = BTRFS_ADD_DELAYED_REF, + .bytenr = ins.objectid, + .num_bytes = ins.offset, + .owning_root = btrfs_root_id(root), + .ref_root = btrfs_root_id(root), + }; + + btrfs_init_data_ref(&ref, wc->log_key.objectid, offset, 0, false); + ret = btrfs_inc_extent_ref(trans, &ref); + if (ret) { + btrfs_abort_log_replay(wc, ret, +"failed to increment data extent for bytenr %llu disk_num_bytes %llu inode %llu root %llu", + ins.objectid, ins.offset, + wc->log_key.objectid, + btrfs_root_id(root)); + goto out; + } + } else { + /* Insert the extent pointer in the extent tree. */ + ret = btrfs_alloc_logged_file_extent(trans, btrfs_root_id(root), + wc->log_key.objectid, offset, &ins); + if (ret) { + btrfs_abort_log_replay(wc, ret, +"failed to allocate logged data extent for bytenr %llu disk_num_bytes %llu offset %llu inode %llu root %llu", + ins.objectid, ins.offset, offset, + wc->log_key.objectid, btrfs_root_id(root)); + goto out; + } + } + + btrfs_release_path(wc->subvol_path); + + if (btrfs_file_extent_compression(wc->log_leaf, item)) { + csum_start = ins.objectid; + csum_end = csum_start + ins.offset; + } else { + csum_start = ins.objectid + btrfs_file_extent_offset(wc->log_leaf, item); + csum_end = csum_start + btrfs_file_extent_num_bytes(wc->log_leaf, item); + } + + ret = btrfs_lookup_csums_list(root->log_root, csum_start, csum_end - 1, + &ordered_sums, false); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to lookups csums for range [%llu, %llu) inode %llu root %llu", + csum_start, csum_end, wc->log_key.objectid, + btrfs_root_id(root)); + goto out; + } + ret = 0; + /* + * Now delete all existing cums in the csum root that cover our range. + * We do this because we can have an extent that is completely + * referenced by one file extent item and partially referenced by + * another file extent item (like after using the clone or extent_same + * ioctls). In this case if we end up doing the replay of the one that + * partially references the extent first, and we do not do the csum + * deletion below, we can get 2 csum items in the csum tree that overlap + * each other. For example, imagine our log has the two following file + * extent items: + * + * key (257 EXTENT_DATA 409600) + * extent data disk byte 12845056 nr 102400 + * extent data offset 20480 nr 20480 ram 102400 + * + * key (257 EXTENT_DATA 819200) + * extent data disk byte 12845056 nr 102400 + * extent data offset 0 nr 102400 ram 102400 + * + * Where the second one fully references the 100K extent that starts at + * disk byte 12845056, and the log tree has a single csum item that + * covers the entire range of the extent: + * + * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 + * + * After the first file extent item is replayed, the csum tree gets the + * following csum item: + * + * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 + * + * Which covers the 20K sub-range starting at offset 20K of our extent. + * Now when we replay the second file extent item, if we do not delete + * existing csum items that cover any of its blocks, we end up getting + * two csum items in our csum tree that overlap each other: + * + * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100 + * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20 + * + * Which is a problem, because after this anyone trying to lookup for + * the checksum of any block of our extent starting at an offset of 40K + * or higher, will end up looking at the second csum item only, which + * does not contain the checksum for any block starting at offset 40K or + * higher of our extent. + */ + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums; + struct btrfs_root *csum_root; + + sums = list_first_entry(&ordered_sums, struct btrfs_ordered_sum, list); + csum_root = btrfs_csum_root(fs_info, sums->logical); + if (unlikely(!csum_root)) { + btrfs_err(fs_info, + "missing csum root for extent at bytenr %llu", + sums->logical); + ret = -EUCLEAN; + } + + if (!ret) { + ret = btrfs_del_csums(trans, csum_root, sums->logical, + sums->len); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to delete csums for range [%llu, %llu) inode %llu root %llu", + sums->logical, + sums->logical + sums->len, + wc->log_key.objectid, + btrfs_root_id(root)); + } + if (!ret) { + ret = btrfs_insert_data_csums(trans, csum_root, sums); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to add csums for range [%llu, %llu) inode %llu root %llu", + sums->logical, + sums->logical + sums->len, + wc->log_key.objectid, + btrfs_root_id(root)); + } + list_del(&sums->list); + kfree(sums); + } + if (ret) + goto out; + +update_inode: + ret = btrfs_inode_set_file_extent_range(inode, start, extent_end - start); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to set file extent range [%llu, %llu) inode %llu root %llu", + start, extent_end, wc->log_key.objectid, + btrfs_root_id(root)); + goto out; + } + + btrfs_update_inode_bytes(inode, nbytes, drop_args.bytes_found); + ret = btrfs_update_inode(trans, inode); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to update inode %llu root %llu", + wc->log_key.objectid, btrfs_root_id(root)); +out: + iput(&inode->vfs_inode); + return ret; +} + +static int unlink_inode_for_log_replay(struct walk_control *wc, + struct btrfs_inode *dir, + struct btrfs_inode *inode, + const struct fscrypt_str *name) +{ + struct btrfs_trans_handle *trans = wc->trans; + int ret; + + ret = btrfs_unlink_inode(trans, dir, inode, name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to unlink inode %llu parent dir %llu name %.*s root %llu", + btrfs_ino(inode), btrfs_ino(dir), name->len, + name->name, btrfs_root_id(inode->root)); + return ret; + } + /* + * Whenever we need to check if a name exists or not, we check the + * fs/subvolume tree. So after an unlink we must run delayed items, so + * that future checks for a name during log replay see that the name + * does not exists anymore. + */ + ret = btrfs_run_delayed_items(trans); + if (ret) + btrfs_abort_log_replay(wc, ret, +"failed to run delayed items current inode %llu parent dir %llu name %.*s root %llu", + btrfs_ino(inode), btrfs_ino(dir), name->len, + name->name, btrfs_root_id(inode->root)); + + return ret; +} + +/* + * when cleaning up conflicts between the directory names in the + * subvolume, directory names in the log and directory names in the + * inode back references, we may have to unlink inodes from directories. + * + * This is a helper function to do the unlink of a specific directory + * item + */ +static noinline int drop_one_dir_item(struct walk_control *wc, + struct btrfs_inode *dir, + struct btrfs_dir_item *di) +{ + struct btrfs_root *root = dir->root; + struct btrfs_inode *inode; + struct fscrypt_str name; + struct extent_buffer *leaf = wc->subvol_path->nodes[0]; + struct btrfs_key location; + int ret; + + btrfs_dir_item_key_to_cpu(leaf, di, &location); + ret = read_alloc_one_name(leaf, di + 1, btrfs_dir_name_len(leaf, di), &name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to allocate name for dir %llu root %llu", + btrfs_ino(dir), btrfs_root_id(root)); + return ret; + } + + btrfs_release_path(wc->subvol_path); + + inode = btrfs_iget_logging(location.objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + btrfs_abort_log_replay(wc, ret, + "failed to open inode %llu parent dir %llu name %.*s root %llu", + location.objectid, btrfs_ino(dir), + name.len, name.name, btrfs_root_id(root)); + inode = NULL; + goto out; + } + + ret = link_to_fixup_dir(wc, location.objectid); + if (ret) + goto out; + + ret = unlink_inode_for_log_replay(wc, dir, inode, &name); +out: + kfree(name.name); + if (inode) + iput(&inode->vfs_inode); + return ret; +} + +/* + * See if a given name and sequence number found in an inode back reference are + * already in a directory and correctly point to this inode. + * + * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it + * exists. + */ +static noinline int inode_in_dir(struct btrfs_root *root, + struct btrfs_path *path, + u64 dirid, u64 objectid, u64 index, + struct fscrypt_str *name) +{ + struct btrfs_dir_item *di; + struct btrfs_key location; + int ret = 0; + + di = btrfs_lookup_dir_index_item(NULL, root, path, dirid, + index, name, 0); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } else if (di) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + if (location.objectid != objectid) + goto out; + } else { + goto out; + } + + btrfs_release_path(path); + di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, 0); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + goto out; + } else if (di) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); + if (location.objectid == objectid) + ret = 1; + } +out: + btrfs_release_path(path); + return ret; +} + +/* + * helper function to check a log tree for a named back reference in + * an inode. This is used to decide if a back reference that is + * found in the subvolume conflicts with what we find in the log. + * + * inode backreferences may have multiple refs in a single item, + * during replay we process one reference at a time, and we don't + * want to delete valid links to a file from the subvolume if that + * link is also in the log. + */ +static noinline int backref_in_log(struct btrfs_root *log, + struct btrfs_key *key, + u64 ref_objectid, + const struct fscrypt_str *name) +{ + BTRFS_PATH_AUTO_FREE(path); + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, log, key, path, 0, 0); + if (ret < 0) + return ret; + if (ret == 1) + return 0; + + if (key->type == BTRFS_INODE_EXTREF_KEY) + ret = !!btrfs_find_name_in_ext_backref(path->nodes[0], + path->slots[0], + ref_objectid, name); + else + ret = !!btrfs_find_name_in_backref(path->nodes[0], + path->slots[0], name); + return ret; +} + +static int unlink_refs_not_in_log(struct walk_control *wc, + struct btrfs_key *search_key, + struct btrfs_inode *dir, + struct btrfs_inode *inode) +{ + struct extent_buffer *leaf = wc->subvol_path->nodes[0]; + unsigned long ptr; + unsigned long ptr_end; + + /* + * Check all the names in this back reference to see if they are in the + * log. If so, we allow them to stay otherwise they must be unlinked as + * a conflict. + */ + ptr = btrfs_item_ptr_offset(leaf, wc->subvol_path->slots[0]); + ptr_end = ptr + btrfs_item_size(leaf, wc->subvol_path->slots[0]); + while (ptr < ptr_end) { + struct fscrypt_str victim_name; + struct btrfs_inode_ref *victim_ref; + int ret; + + victim_ref = (struct btrfs_inode_ref *)ptr; + ret = read_alloc_one_name(leaf, (victim_ref + 1), + btrfs_inode_ref_name_len(leaf, victim_ref), + &victim_name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to allocate name for inode %llu parent dir %llu root %llu", + btrfs_ino(inode), btrfs_ino(dir), + btrfs_root_id(inode->root)); + return ret; + } + + ret = backref_in_log(wc->log, search_key, btrfs_ino(dir), &victim_name); + if (ret) { + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to check if backref is in log tree for inode %llu parent dir %llu name %.*s root %llu", + btrfs_ino(inode), btrfs_ino(dir), + victim_name.len, victim_name.name, + btrfs_root_id(inode->root)); + kfree(victim_name.name); + return ret; + } + kfree(victim_name.name); + ptr = (unsigned long)(victim_ref + 1) + victim_name.len; + continue; + } + + inc_nlink(&inode->vfs_inode); + btrfs_release_path(wc->subvol_path); + + ret = unlink_inode_for_log_replay(wc, dir, inode, &victim_name); + kfree(victim_name.name); + if (ret) + return ret; + return -EAGAIN; + } + + return 0; +} + +static int unlink_extrefs_not_in_log(struct walk_control *wc, + struct btrfs_key *search_key, + struct btrfs_inode *dir, + struct btrfs_inode *inode) +{ + struct extent_buffer *leaf = wc->subvol_path->nodes[0]; + const unsigned long base = btrfs_item_ptr_offset(leaf, wc->subvol_path->slots[0]); + const u32 item_size = btrfs_item_size(leaf, wc->subvol_path->slots[0]); + u32 cur_offset = 0; + + while (cur_offset < item_size) { + struct btrfs_root *log_root = wc->log; + struct btrfs_inode_extref *extref; + struct fscrypt_str victim_name; + int ret; + + extref = (struct btrfs_inode_extref *)(base + cur_offset); + victim_name.len = btrfs_inode_extref_name_len(leaf, extref); + + if (btrfs_inode_extref_parent(leaf, extref) != btrfs_ino(dir)) + goto next; + + ret = read_alloc_one_name(leaf, &extref->name, victim_name.len, + &victim_name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to allocate name for inode %llu parent dir %llu root %llu", + btrfs_ino(inode), btrfs_ino(dir), + btrfs_root_id(inode->root)); + return ret; + } + + search_key->objectid = btrfs_ino(inode); + search_key->type = BTRFS_INODE_EXTREF_KEY; + search_key->offset = btrfs_extref_hash(btrfs_ino(dir), + victim_name.name, + victim_name.len); + ret = backref_in_log(log_root, search_key, btrfs_ino(dir), &victim_name); + if (ret) { + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to check if backref is in log tree for inode %llu parent dir %llu name %.*s root %llu", + btrfs_ino(inode), btrfs_ino(dir), + victim_name.len, victim_name.name, + btrfs_root_id(inode->root)); + kfree(victim_name.name); + return ret; + } + kfree(victim_name.name); +next: + cur_offset += victim_name.len + sizeof(*extref); + continue; + } + + inc_nlink(&inode->vfs_inode); + btrfs_release_path(wc->subvol_path); + + ret = unlink_inode_for_log_replay(wc, dir, inode, &victim_name); + kfree(victim_name.name); + if (ret) + return ret; + return -EAGAIN; + } + + return 0; +} + +static inline int __add_inode_ref(struct walk_control *wc, + struct btrfs_inode *dir, + struct btrfs_inode *inode, + u64 ref_index, struct fscrypt_str *name) +{ + int ret; + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_dir_item *di; + struct btrfs_key search_key; + struct btrfs_inode_extref *extref; + +again: + /* Search old style refs */ + search_key.objectid = btrfs_ino(inode); + search_key.type = BTRFS_INODE_REF_KEY; + search_key.offset = btrfs_ino(dir); + ret = btrfs_search_slot(NULL, root, &search_key, wc->subvol_path, 0, 0); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to search subvolume tree for key " BTRFS_KEY_FMT " root %llu", + BTRFS_KEY_FMT_VALUE(&search_key), + btrfs_root_id(root)); + return ret; + } else if (ret == 0) { + /* + * Are we trying to overwrite a back ref for the root directory? + * If so, we're done. + */ + if (search_key.objectid == search_key.offset) + return 1; + + ret = unlink_refs_not_in_log(wc, &search_key, dir, inode); + if (ret == -EAGAIN) + goto again; + else if (ret) + return ret; + } + btrfs_release_path(wc->subvol_path); + + /* Same search but for extended refs */ + extref = btrfs_lookup_inode_extref(root, wc->subvol_path, name, + btrfs_ino(inode), btrfs_ino(dir)); + if (IS_ERR(extref)) { + return PTR_ERR(extref); + } else if (extref) { + ret = unlink_extrefs_not_in_log(wc, &search_key, dir, inode); + if (ret == -EAGAIN) + goto again; + else if (ret) + return ret; + } + btrfs_release_path(wc->subvol_path); + + /* look for a conflicting sequence number */ + di = btrfs_lookup_dir_index_item(trans, root, wc->subvol_path, btrfs_ino(dir), + ref_index, name, 0); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + btrfs_abort_log_replay(wc, ret, +"failed to lookup dir index item for dir %llu ref_index %llu name %.*s root %llu", + btrfs_ino(dir), ref_index, name->len, + name->name, btrfs_root_id(root)); + return ret; + } else if (di) { + ret = drop_one_dir_item(wc, dir, di); + if (ret) + return ret; + } + btrfs_release_path(wc->subvol_path); + + /* look for a conflicting name */ + di = btrfs_lookup_dir_item(trans, root, wc->subvol_path, btrfs_ino(dir), name, 0); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir item for dir %llu name %.*s root %llu", + btrfs_ino(dir), name->len, name->name, + btrfs_root_id(root)); + return ret; + } else if (di) { + ret = drop_one_dir_item(wc, dir, di); + if (ret) + return ret; + } + btrfs_release_path(wc->subvol_path); + + return 0; +} + +static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, + struct fscrypt_str *name, u64 *index, + u64 *parent_objectid) +{ + struct btrfs_inode_extref *extref; + int ret; + + extref = (struct btrfs_inode_extref *)ref_ptr; + + ret = read_alloc_one_name(eb, &extref->name, + btrfs_inode_extref_name_len(eb, extref), name); + if (ret) + return ret; + + if (index) + *index = btrfs_inode_extref_index(eb, extref); + if (parent_objectid) + *parent_objectid = btrfs_inode_extref_parent(eb, extref); + + return 0; +} + +static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr, + struct fscrypt_str *name, u64 *index) +{ + struct btrfs_inode_ref *ref; + int ret; + + ref = (struct btrfs_inode_ref *)ref_ptr; + + ret = read_alloc_one_name(eb, ref + 1, btrfs_inode_ref_name_len(eb, ref), + name); + if (ret) + return ret; + + if (index) + *index = btrfs_inode_ref_index(eb, ref); + + return 0; +} + +/* + * Take an inode reference item from the log tree and iterate all names from the + * inode reference item in the subvolume tree with the same key (if it exists). + * For any name that is not in the inode reference item from the log tree, do a + * proper unlink of that name (that is, remove its entry from the inode + * reference item and both dir index keys). + */ +static int unlink_old_inode_refs(struct walk_control *wc, struct btrfs_inode *inode) +{ + struct btrfs_root *root = wc->root; + int ret; + unsigned long ref_ptr; + unsigned long ref_end; + struct extent_buffer *eb; + +again: + btrfs_release_path(wc->subvol_path); + ret = btrfs_search_slot(NULL, root, &wc->log_key, wc->subvol_path, 0, 0); + if (ret > 0) { + ret = 0; + goto out; + } + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to search subvolume tree for key " BTRFS_KEY_FMT " root %llu", + BTRFS_KEY_FMT_VALUE(&wc->log_key), + btrfs_root_id(root)); + goto out; + } + + eb = wc->subvol_path->nodes[0]; + ref_ptr = btrfs_item_ptr_offset(eb, wc->subvol_path->slots[0]); + ref_end = ref_ptr + btrfs_item_size(eb, wc->subvol_path->slots[0]); + while (ref_ptr < ref_end) { + struct fscrypt_str name; + u64 parent_id; + + if (wc->log_key.type == BTRFS_INODE_EXTREF_KEY) { + ret = extref_get_fields(eb, ref_ptr, &name, + NULL, &parent_id); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to get extref details for inode %llu root %llu", + btrfs_ino(inode), + btrfs_root_id(root)); + goto out; + } + } else { + parent_id = wc->log_key.offset; + ret = ref_get_fields(eb, ref_ptr, &name, NULL); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to get ref details for inode %llu parent_id %llu root %llu", + btrfs_ino(inode), parent_id, + btrfs_root_id(root)); + goto out; + } + } + + if (wc->log_key.type == BTRFS_INODE_EXTREF_KEY) + ret = !!btrfs_find_name_in_ext_backref(wc->log_leaf, wc->log_slot, + parent_id, &name); + else + ret = !!btrfs_find_name_in_backref(wc->log_leaf, wc->log_slot, + &name); + + if (!ret) { + struct btrfs_inode *dir; + + btrfs_release_path(wc->subvol_path); + dir = btrfs_iget_logging(parent_id, root); + if (IS_ERR(dir)) { + ret = PTR_ERR(dir); + kfree(name.name); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir inode %llu root %llu", + parent_id, btrfs_root_id(root)); + goto out; + } + ret = unlink_inode_for_log_replay(wc, dir, inode, &name); + kfree(name.name); + iput(&dir->vfs_inode); + if (ret) + goto out; + goto again; + } + + kfree(name.name); + ref_ptr += name.len; + if (wc->log_key.type == BTRFS_INODE_EXTREF_KEY) + ref_ptr += sizeof(struct btrfs_inode_extref); + else + ref_ptr += sizeof(struct btrfs_inode_ref); + } + ret = 0; + out: + btrfs_release_path(wc->subvol_path); + return ret; +} + +/* + * Replay one inode back reference item found in the log tree. + * Path is for temporary use by this function (it should be released on return). + */ +static noinline int add_inode_ref(struct walk_control *wc) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_inode *dir = NULL; + struct btrfs_inode *inode = NULL; + unsigned long ref_ptr; + unsigned long ref_end; + struct fscrypt_str name = { 0 }; + int ret; + const bool is_extref_item = (wc->log_key.type == BTRFS_INODE_EXTREF_KEY); + u64 parent_objectid; + u64 inode_objectid; + u64 ref_index = 0; + int ref_struct_size; + + ref_ptr = btrfs_item_ptr_offset(wc->log_leaf, wc->log_slot); + ref_end = ref_ptr + btrfs_item_size(wc->log_leaf, wc->log_slot); + + if (is_extref_item) { + struct btrfs_inode_extref *r; + + ref_struct_size = sizeof(struct btrfs_inode_extref); + r = (struct btrfs_inode_extref *)ref_ptr; + parent_objectid = btrfs_inode_extref_parent(wc->log_leaf, r); + } else { + ref_struct_size = sizeof(struct btrfs_inode_ref); + parent_objectid = wc->log_key.offset; + } + inode_objectid = wc->log_key.objectid; + + /* + * it is possible that we didn't log all the parent directories + * for a given inode. If we don't find the dir, just don't + * copy the back ref in. The link count fixup code will take + * care of the rest + */ + dir = btrfs_iget_logging(parent_objectid, root); + if (IS_ERR(dir)) { + ret = PTR_ERR(dir); + if (ret == -ENOENT) + ret = 0; + else + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir inode %llu root %llu", + parent_objectid, btrfs_root_id(root)); + dir = NULL; + goto out; + } + + inode = btrfs_iget_logging(inode_objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + btrfs_abort_log_replay(wc, ret, + "failed to lookup inode %llu root %llu", + inode_objectid, btrfs_root_id(root)); + inode = NULL; + goto out; + } + + while (ref_ptr < ref_end) { + if (is_extref_item) { + ret = extref_get_fields(wc->log_leaf, ref_ptr, &name, + &ref_index, &parent_objectid); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to get extref details for inode %llu root %llu", + btrfs_ino(inode), + btrfs_root_id(root)); + goto out; + } + /* + * parent object can change from one array + * item to another. + */ + if (!dir) { + dir = btrfs_iget_logging(parent_objectid, root); + if (IS_ERR(dir)) { + ret = PTR_ERR(dir); + dir = NULL; + /* + * A new parent dir may have not been + * logged and not exist in the subvolume + * tree, see the comment above before + * the loop when getting the first + * parent dir. + */ + if (ret == -ENOENT) { + /* + * The next extref may refer to + * another parent dir that + * exists, so continue. + */ + ret = 0; + goto next; + } else { + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir inode %llu root %llu", + parent_objectid, + btrfs_root_id(root)); + } + goto out; + } + } + } else { + ret = ref_get_fields(wc->log_leaf, ref_ptr, &name, &ref_index); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to get ref details for inode %llu parent_objectid %llu root %llu", + btrfs_ino(inode), + parent_objectid, + btrfs_root_id(root)); + goto out; + } + } + + ret = inode_in_dir(root, wc->subvol_path, btrfs_ino(dir), + btrfs_ino(inode), ref_index, &name); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to check if inode %llu is in dir %llu ref_index %llu name %.*s root %llu", + btrfs_ino(inode), btrfs_ino(dir), + ref_index, name.len, name.name, + btrfs_root_id(root)); + goto out; + } else if (ret == 0) { + /* + * look for a conflicting back reference in the + * metadata. if we find one we have to unlink that name + * of the file before we add our new link. Later on, we + * overwrite any existing back reference, and we don't + * want to create dangling pointers in the directory. + */ + ret = __add_inode_ref(wc, dir, inode, ref_index, &name); + if (ret) { + if (ret == 1) + ret = 0; + goto out; + } + + /* insert our name */ + ret = btrfs_add_link(trans, dir, inode, &name, false, ref_index); + if (ret) { + btrfs_abort_log_replay(wc, ret, +"failed to add link for inode %llu in dir %llu ref_index %llu name %.*s root %llu", + btrfs_ino(inode), + btrfs_ino(dir), ref_index, + name.len, name.name, + btrfs_root_id(root)); + goto out; + } + + ret = btrfs_update_inode(trans, inode); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to update inode %llu root %llu", + btrfs_ino(inode), + btrfs_root_id(root)); + goto out; + } + } + /* Else, ret == 1, we already have a perfect match, we're done. */ + +next: + ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + name.len; + kfree(name.name); + name.name = NULL; + if (is_extref_item && dir) { + iput(&dir->vfs_inode); + dir = NULL; + } + } + + /* + * Before we overwrite the inode reference item in the subvolume tree + * with the item from the log tree, we must unlink all names from the + * parent directory that are in the subvolume's tree inode reference + * item, otherwise we end up with an inconsistent subvolume tree where + * dir index entries exist for a name but there is no inode reference + * item with the same name. + */ + ret = unlink_old_inode_refs(wc, inode); + if (ret) + goto out; + + /* finally write the back reference in the inode */ + ret = overwrite_item(wc); +out: + btrfs_release_path(wc->subvol_path); + kfree(name.name); + if (dir) + iput(&dir->vfs_inode); + if (inode) + iput(&inode->vfs_inode); + return ret; +} + +static int count_inode_extrefs(struct btrfs_inode *inode, struct btrfs_path *path) +{ + int ret = 0; + int name_len; + unsigned int nlink = 0; + u32 item_size; + u32 cur_offset = 0; + u64 inode_objectid = btrfs_ino(inode); + u64 offset = 0; + unsigned long ptr; + struct btrfs_inode_extref *extref; + struct extent_buffer *leaf; + + while (1) { + ret = btrfs_find_one_extref(inode->root, inode_objectid, offset, + path, &extref, &offset); + if (ret) + break; + + leaf = path->nodes[0]; + item_size = btrfs_item_size(leaf, path->slots[0]); + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + cur_offset = 0; + + while (cur_offset < item_size) { + extref = (struct btrfs_inode_extref *) (ptr + cur_offset); + name_len = btrfs_inode_extref_name_len(leaf, extref); + + nlink++; + + cur_offset += name_len + sizeof(*extref); + } + + offset++; + btrfs_release_path(path); + } + btrfs_release_path(path); + + if (ret < 0 && ret != -ENOENT) + return ret; + return nlink; +} + +static int count_inode_refs(struct btrfs_inode *inode, struct btrfs_path *path) +{ + int ret; + struct btrfs_key key; + unsigned int nlink = 0; + unsigned long ptr; + unsigned long ptr_end; + int name_len; + u64 ino = btrfs_ino(inode); + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(NULL, inode->root, &key, path, 0, 0); + if (ret < 0) + break; + if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } +process_slot: + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid != ino || + key.type != BTRFS_INODE_REF_KEY) + break; + ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]); + ptr_end = ptr + btrfs_item_size(path->nodes[0], + path->slots[0]); + while (ptr < ptr_end) { + struct btrfs_inode_ref *ref; + + ref = (struct btrfs_inode_ref *)ptr; + name_len = btrfs_inode_ref_name_len(path->nodes[0], + ref); + ptr = (unsigned long)(ref + 1) + name_len; + nlink++; + } + + if (key.offset == 0) + break; + if (path->slots[0] > 0) { + path->slots[0]--; + goto process_slot; + } + key.offset--; + btrfs_release_path(path); + } + btrfs_release_path(path); + + return nlink; +} + +/* + * There are a few corners where the link count of the file can't + * be properly maintained during replay. So, instead of adding + * lots of complexity to the log code, we just scan the backrefs + * for any file that has been through replay. + * + * The scan will update the link count on the inode to reflect the + * number of back refs found. If it goes down to zero, the iput + * will free the inode. + */ +static noinline int fixup_inode_link_count(struct walk_control *wc, + struct btrfs_inode *inode) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = inode->root; + int ret; + u64 nlink = 0; + const u64 ino = btrfs_ino(inode); + + ret = count_inode_refs(inode, wc->subvol_path); + if (ret < 0) + goto out; + + nlink = ret; + + ret = count_inode_extrefs(inode, wc->subvol_path); + if (ret < 0) + goto out; + + nlink += ret; + + ret = 0; + + if (nlink != inode->vfs_inode.i_nlink) { + set_nlink(&inode->vfs_inode, nlink); + ret = btrfs_update_inode(trans, inode); + if (ret) + goto out; + } + if (S_ISDIR(inode->vfs_inode.i_mode)) + inode->index_cnt = (u64)-1; + + if (inode->vfs_inode.i_nlink == 0) { + if (S_ISDIR(inode->vfs_inode.i_mode)) { + ret = replay_dir_deletes(wc, ino, true); + if (ret) + goto out; + } + ret = btrfs_insert_orphan_item(trans, root, ino); + if (ret == -EEXIST) + ret = 0; + } + +out: + btrfs_release_path(wc->subvol_path); + return ret; +} + +static noinline int fixup_inode_link_counts(struct walk_control *wc) +{ + int ret; + struct btrfs_key key; + + key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = (u64)-1; + while (1) { + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_inode *inode; + + ret = btrfs_search_slot(trans, root, &key, wc->subvol_path, -1, 1); + if (ret < 0) + break; + + if (ret == 1) { + ret = 0; + if (wc->subvol_path->slots[0] == 0) + break; + wc->subvol_path->slots[0]--; + } + + btrfs_item_key_to_cpu(wc->subvol_path->nodes[0], &key, wc->subvol_path->slots[0]); + if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID || + key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + ret = btrfs_del_item(trans, root, wc->subvol_path); + if (ret) + break; + + btrfs_release_path(wc->subvol_path); + inode = btrfs_iget_logging(key.offset, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + break; + } + + ret = fixup_inode_link_count(wc, inode); + iput(&inode->vfs_inode); + if (ret) + break; + + /* + * fixup on a directory may create new entries, + * make sure we always look for the highest possible + * offset + */ + key.offset = (u64)-1; + } + btrfs_release_path(wc->subvol_path); + return ret; +} + + +/* + * record a given inode in the fixup dir so we can check its link + * count when replay is done. The link count is incremented here + * so the inode won't go away until we check it + */ +static noinline int link_to_fixup_dir(struct walk_control *wc, u64 objectid) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_key key; + int ret = 0; + struct btrfs_inode *inode; + struct inode *vfs_inode; + + inode = btrfs_iget_logging(objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + btrfs_abort_log_replay(wc, ret, + "failed to lookup inode %llu root %llu", + objectid, btrfs_root_id(root)); + return ret; + } + + vfs_inode = &inode->vfs_inode; + key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = objectid; + + ret = btrfs_insert_empty_item(trans, root, wc->subvol_path, &key, 0); + + btrfs_release_path(wc->subvol_path); + if (ret == 0) { + if (!vfs_inode->i_nlink) + set_nlink(vfs_inode, 1); + else + inc_nlink(vfs_inode); + ret = btrfs_update_inode(trans, inode); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to update inode %llu root %llu", + objectid, btrfs_root_id(root)); + } else if (ret == -EEXIST) { + ret = 0; + } else { + btrfs_abort_log_replay(wc, ret, + "failed to insert fixup item for inode %llu root %llu", + objectid, btrfs_root_id(root)); + } + iput(vfs_inode); + + return ret; +} + +/* + * when replaying the log for a directory, we only insert names + * for inodes that actually exist. This means an fsync on a directory + * does not implicitly fsync all the new files in it + */ +static noinline int insert_one_name(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 dirid, u64 index, + const struct fscrypt_str *name, + struct btrfs_key *location) +{ + struct btrfs_inode *inode; + struct btrfs_inode *dir; + int ret; + + inode = btrfs_iget_logging(location->objectid, root); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + dir = btrfs_iget_logging(dirid, root); + if (IS_ERR(dir)) { + iput(&inode->vfs_inode); + return PTR_ERR(dir); + } + + ret = btrfs_add_link(trans, dir, inode, name, true, index); + + /* FIXME, put inode into FIXUP list */ + + iput(&inode->vfs_inode); + iput(&dir->vfs_inode); + return ret; +} + +static int delete_conflicting_dir_entry(struct walk_control *wc, + struct btrfs_inode *dir, + struct btrfs_dir_item *dst_di, + const struct btrfs_key *log_key, + u8 log_flags, + bool exists) +{ + struct btrfs_key found_key; + + btrfs_dir_item_key_to_cpu(wc->subvol_path->nodes[0], dst_di, &found_key); + /* The existing dentry points to the same inode, don't delete it. */ + if (found_key.objectid == log_key->objectid && + found_key.type == log_key->type && + found_key.offset == log_key->offset && + btrfs_dir_flags(wc->subvol_path->nodes[0], dst_di) == log_flags) + return 1; + + /* + * Don't drop the conflicting directory entry if the inode for the new + * entry doesn't exist. + */ + if (!exists) + return 0; + + return drop_one_dir_item(wc, dir, dst_di); +} + +/* + * take a single entry in a log directory item and replay it into + * the subvolume. + * + * if a conflicting item exists in the subdirectory already, + * the inode it points to is unlinked and put into the link count + * fix up tree. + * + * If a name from the log points to a file or directory that does + * not exist in the FS, it is skipped. fsyncs on directories + * do not force down inodes inside that directory, just changes to the + * names or unlinks in a directory. + * + * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a + * non-existing inode) and 1 if the name was replayed. + */ +static noinline int replay_one_name(struct walk_control *wc, struct btrfs_dir_item *di) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct fscrypt_str name = { 0 }; + struct btrfs_dir_item *dir_dst_di; + struct btrfs_dir_item *index_dst_di; + bool dir_dst_matches = false; + bool index_dst_matches = false; + struct btrfs_key log_key; + struct btrfs_key search_key; + struct btrfs_inode *dir; + u8 log_flags; + bool exists; + int ret; + bool update_size = true; + bool name_added = false; + + dir = btrfs_iget_logging(wc->log_key.objectid, root); + if (IS_ERR(dir)) { + ret = PTR_ERR(dir); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir inode %llu root %llu", + wc->log_key.objectid, btrfs_root_id(root)); + return ret; + } + + ret = read_alloc_one_name(wc->log_leaf, di + 1, + btrfs_dir_name_len(wc->log_leaf, di), &name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to allocate name for dir %llu root %llu", + btrfs_ino(dir), btrfs_root_id(root)); + goto out; + } + + log_flags = btrfs_dir_flags(wc->log_leaf, di); + btrfs_dir_item_key_to_cpu(wc->log_leaf, di, &log_key); + ret = btrfs_lookup_inode(trans, root, wc->subvol_path, &log_key, 0); + btrfs_release_path(wc->subvol_path); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to lookup inode %llu root %llu", + log_key.objectid, btrfs_root_id(root)); + goto out; + } + exists = (ret == 0); + ret = 0; + + dir_dst_di = btrfs_lookup_dir_item(trans, root, wc->subvol_path, + wc->log_key.objectid, &name, 1); + if (IS_ERR(dir_dst_di)) { + ret = PTR_ERR(dir_dst_di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir item for dir %llu name %.*s root %llu", + wc->log_key.objectid, name.len, name.name, + btrfs_root_id(root)); + goto out; + } else if (dir_dst_di) { + ret = delete_conflicting_dir_entry(wc, dir, dir_dst_di, + &log_key, log_flags, exists); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to delete conflicting entry for dir %llu name %.*s root %llu", + btrfs_ino(dir), name.len, name.name, + btrfs_root_id(root)); + goto out; + } + dir_dst_matches = (ret == 1); + } + + btrfs_release_path(wc->subvol_path); + + index_dst_di = btrfs_lookup_dir_index_item(trans, root, wc->subvol_path, + wc->log_key.objectid, + wc->log_key.offset, &name, 1); + if (IS_ERR(index_dst_di)) { + ret = PTR_ERR(index_dst_di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir index item for dir %llu name %.*s root %llu", + wc->log_key.objectid, name.len, name.name, + btrfs_root_id(root)); + goto out; + } else if (index_dst_di) { + ret = delete_conflicting_dir_entry(wc, dir, index_dst_di, + &log_key, log_flags, exists); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to delete conflicting entry for dir %llu name %.*s root %llu", + btrfs_ino(dir), name.len, name.name, + btrfs_root_id(root)); + goto out; + } + index_dst_matches = (ret == 1); + } + + btrfs_release_path(wc->subvol_path); + + if (dir_dst_matches && index_dst_matches) { + ret = 0; + update_size = false; + goto out; + } + + /* + * Check if the inode reference exists in the log for the given name, + * inode and parent inode + */ + search_key.objectid = log_key.objectid; + search_key.type = BTRFS_INODE_REF_KEY; + search_key.offset = wc->log_key.objectid; + ret = backref_in_log(root->log_root, &search_key, 0, &name); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to check if ref item is logged for inode %llu dir %llu name %.*s root %llu", + search_key.objectid, btrfs_ino(dir), + name.len, name.name, btrfs_root_id(root)); + goto out; + } else if (ret) { + /* The dentry will be added later. */ + ret = 0; + update_size = false; + goto out; + } + + search_key.objectid = log_key.objectid; + search_key.type = BTRFS_INODE_EXTREF_KEY; + search_key.offset = btrfs_extref_hash(wc->log_key.objectid, name.name, name.len); + ret = backref_in_log(root->log_root, &search_key, wc->log_key.objectid, &name); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, +"failed to check if extref item is logged for inode %llu dir %llu name %.*s root %llu", + search_key.objectid, btrfs_ino(dir), + name.len, name.name, btrfs_root_id(root)); + goto out; + } else if (ret) { + /* The dentry will be added later. */ + ret = 0; + update_size = false; + goto out; + } + ret = insert_one_name(trans, root, wc->log_key.objectid, wc->log_key.offset, + &name, &log_key); + if (ret && ret != -ENOENT && ret != -EEXIST) { + btrfs_abort_log_replay(wc, ret, + "failed to insert name %.*s for inode %llu dir %llu root %llu", + name.len, name.name, log_key.objectid, + btrfs_ino(dir), btrfs_root_id(root)); + goto out; + } + if (!ret) + name_added = true; + update_size = false; + ret = 0; + +out: + if (!ret && update_size) { + btrfs_i_size_write(dir, dir->vfs_inode.i_size + name.len * 2); + ret = btrfs_update_inode(trans, dir); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to update dir inode %llu root %llu", + btrfs_ino(dir), btrfs_root_id(root)); + } + kfree(name.name); + iput(&dir->vfs_inode); + if (!ret && name_added) + ret = 1; + return ret; +} + +/* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */ +static noinline int replay_one_dir_item(struct walk_control *wc) +{ + int ret; + struct btrfs_dir_item *di; + + /* We only log dir index keys, which only contain a single dir item. */ + ASSERT(wc->log_key.type == BTRFS_DIR_INDEX_KEY, + "wc->log_key.type=%u", wc->log_key.type); + + di = btrfs_item_ptr(wc->log_leaf, wc->log_slot, struct btrfs_dir_item); + ret = replay_one_name(wc, di); + if (ret < 0) + return ret; + + /* + * If this entry refers to a non-directory (directories can not have a + * link count > 1) and it was added in the transaction that was not + * committed, make sure we fixup the link count of the inode the entry + * points to. Otherwise something like the following would result in a + * directory pointing to an inode with a wrong link that does not account + * for this dir entry: + * + * mkdir testdir + * touch testdir/foo + * touch testdir/bar + * sync + * + * ln testdir/bar testdir/bar_link + * ln testdir/foo testdir/foo_link + * xfs_io -c "fsync" testdir/bar + * + * <power failure> + * + * mount fs, log replay happens + * + * File foo would remain with a link count of 1 when it has two entries + * pointing to it in the directory testdir. This would make it impossible + * to ever delete the parent directory has it would result in stale + * dentries that can never be deleted. + */ + if (ret == 1 && btrfs_dir_ftype(wc->log_leaf, di) != BTRFS_FT_DIR) { + struct btrfs_key di_key; + + btrfs_dir_item_key_to_cpu(wc->log_leaf, di, &di_key); + ret = link_to_fixup_dir(wc, di_key.objectid); + } + + return ret; +} + +/* + * directory replay has two parts. There are the standard directory + * items in the log copied from the subvolume, and range items + * created in the log while the subvolume was logged. + * + * The range items tell us which parts of the key space the log + * is authoritative for. During replay, if a key in the subvolume + * directory is in a logged range item, but not actually in the log + * that means it was deleted from the directory before the fsync + * and should be removed. + */ +static noinline int find_dir_range(struct btrfs_root *root, + struct btrfs_path *path, + u64 dirid, + u64 *start_ret, u64 *end_ret) +{ + struct btrfs_key key; + u64 found_end; + struct btrfs_dir_log_item *item; + int ret; + int nritems; + + if (*start_ret == (u64)-1) + return 1; + + key.objectid = dirid; + key.type = BTRFS_DIR_LOG_INDEX_KEY; + key.offset = *start_ret; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + if (ret > 0) { + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + } + if (ret != 0) + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) { + ret = 1; + goto next; + } + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + found_end = btrfs_dir_log_end(path->nodes[0], item); + + if (*start_ret >= key.offset && *start_ret <= found_end) { + ret = 0; + *start_ret = key.offset; + *end_ret = found_end; + goto out; + } + ret = 1; +next: + /* check the next slot in the tree to see if it is a valid item */ + nritems = btrfs_header_nritems(path->nodes[0]); + path->slots[0]++; + if (path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, path); + if (ret) + goto out; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) { + ret = 1; + goto out; + } + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + found_end = btrfs_dir_log_end(path->nodes[0], item); + *start_ret = key.offset; + *end_ret = found_end; + ret = 0; +out: + btrfs_release_path(path); + return ret; +} + +/* + * this looks for a given directory item in the log. If the directory + * item is not in the log, the item is removed and the inode it points + * to is unlinked + */ +static noinline int check_item_in_log(struct walk_control *wc, + struct btrfs_path *log_path, + struct btrfs_inode *dir, + struct btrfs_key *dir_key, + bool force_remove) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = dir->root; + int ret; + struct extent_buffer *eb; + int slot; + struct btrfs_dir_item *di; + struct fscrypt_str name = { 0 }; + struct btrfs_inode *inode = NULL; + struct btrfs_key location; + + /* + * Currently we only log dir index keys. Even if we replay a log created + * by an older kernel that logged both dir index and dir item keys, all + * we need to do is process the dir index keys, we (and our caller) can + * safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY). + */ + ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY, "dir_key->type=%u", dir_key->type); + + eb = wc->subvol_path->nodes[0]; + slot = wc->subvol_path->slots[0]; + di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item); + ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to allocate name for dir %llu index %llu root %llu", + btrfs_ino(dir), dir_key->offset, + btrfs_root_id(root)); + goto out; + } + + if (!force_remove) { + struct btrfs_dir_item *log_di; + + log_di = btrfs_lookup_dir_index_item(trans, wc->log, log_path, + dir_key->objectid, + dir_key->offset, &name, 0); + if (IS_ERR(log_di)) { + ret = PTR_ERR(log_di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir index item for dir %llu index %llu name %.*s root %llu", + btrfs_ino(dir), dir_key->offset, + name.len, name.name, + btrfs_root_id(root)); + goto out; + } else if (log_di) { + /* The dentry exists in the log, we have nothing to do. */ + ret = 0; + goto out; + } + } + + btrfs_dir_item_key_to_cpu(eb, di, &location); + btrfs_release_path(wc->subvol_path); + btrfs_release_path(log_path); + inode = btrfs_iget_logging(location.objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + inode = NULL; + btrfs_abort_log_replay(wc, ret, + "failed to lookup inode %llu root %llu", + location.objectid, btrfs_root_id(root)); + goto out; + } + + ret = link_to_fixup_dir(wc, location.objectid); + if (ret) + goto out; + + inc_nlink(&inode->vfs_inode); + ret = unlink_inode_for_log_replay(wc, dir, inode, &name); + /* + * Unlike dir item keys, dir index keys can only have one name (entry) in + * them, as there are no key collisions since each key has a unique offset + * (an index number), so we're done. + */ +out: + btrfs_release_path(wc->subvol_path); + btrfs_release_path(log_path); + kfree(name.name); + if (inode) + iput(&inode->vfs_inode); + return ret; +} + +static int replay_xattr_deletes(struct walk_control *wc) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_root *root = wc->root; + struct btrfs_root *log = wc->log; + struct btrfs_key search_key; + BTRFS_PATH_AUTO_FREE(log_path); + const u64 ino = wc->log_key.objectid; + int nritems; + int ret; + + log_path = btrfs_alloc_path(); + if (!log_path) { + btrfs_abort_log_replay(wc, -ENOMEM, "failed to allocate path"); + return -ENOMEM; + } + + search_key.objectid = ino; + search_key.type = BTRFS_XATTR_ITEM_KEY; + search_key.offset = 0; +again: + ret = btrfs_search_slot(NULL, root, &search_key, wc->subvol_path, 0, 0); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to search xattrs for inode %llu root %llu", + ino, btrfs_root_id(root)); + goto out; + } +process_leaf: + nritems = btrfs_header_nritems(wc->subvol_path->nodes[0]); + for (int i = wc->subvol_path->slots[0]; i < nritems; i++) { + struct btrfs_key key; + struct btrfs_dir_item *di; + struct btrfs_dir_item *log_di; + u32 total_size; + u32 cur; + + btrfs_item_key_to_cpu(wc->subvol_path->nodes[0], &key, i); + if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) { + ret = 0; + goto out; + } + + di = btrfs_item_ptr(wc->subvol_path->nodes[0], i, struct btrfs_dir_item); + total_size = btrfs_item_size(wc->subvol_path->nodes[0], i); + cur = 0; + while (cur < total_size) { + u16 name_len = btrfs_dir_name_len(wc->subvol_path->nodes[0], di); + u16 data_len = btrfs_dir_data_len(wc->subvol_path->nodes[0], di); + u32 this_len = sizeof(*di) + name_len + data_len; + char *name; + + name = kmalloc(name_len, GFP_NOFS); + if (!name) { + ret = -ENOMEM; + btrfs_abort_log_replay(wc, ret, + "failed to allocate memory for name of length %u", + name_len); + goto out; + } + read_extent_buffer(wc->subvol_path->nodes[0], name, + (unsigned long)(di + 1), name_len); + + log_di = btrfs_lookup_xattr(NULL, log, log_path, ino, + name, name_len, 0); + btrfs_release_path(log_path); + if (!log_di) { + /* Doesn't exist in log tree, so delete it. */ + btrfs_release_path(wc->subvol_path); + di = btrfs_lookup_xattr(trans, root, wc->subvol_path, ino, + name, name_len, -1); + if (IS_ERR(di)) { + ret = PTR_ERR(di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup xattr with name %.*s for inode %llu root %llu", + name_len, name, ino, + btrfs_root_id(root)); + kfree(name); + goto out; + } + ASSERT(di); + ret = btrfs_delete_one_dir_name(trans, root, + wc->subvol_path, di); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to delete xattr with name %.*s for inode %llu root %llu", + name_len, name, ino, + btrfs_root_id(root)); + kfree(name); + goto out; + } + btrfs_release_path(wc->subvol_path); + kfree(name); + search_key = key; + goto again; + } + if (IS_ERR(log_di)) { + ret = PTR_ERR(log_di); + btrfs_abort_log_replay(wc, ret, + "failed to lookup xattr in log tree with name %.*s for inode %llu root %llu", + name_len, name, ino, + btrfs_root_id(root)); + kfree(name); + goto out; + } + kfree(name); + cur += this_len; + di = (struct btrfs_dir_item *)((char *)di + this_len); + } + } + ret = btrfs_next_leaf(root, wc->subvol_path); + if (ret > 0) + ret = 0; + else if (ret == 0) + goto process_leaf; + else + btrfs_abort_log_replay(wc, ret, + "failed to get next leaf in subvolume root %llu", + btrfs_root_id(root)); +out: + btrfs_release_path(wc->subvol_path); + return ret; +} + + +/* + * deletion replay happens before we copy any new directory items + * out of the log or out of backreferences from inodes. It + * scans the log to find ranges of keys that log is authoritative for, + * and then scans the directory to find items in those ranges that are + * not present in the log. + * + * Anything we don't find in the log is unlinked and removed from the + * directory. + */ +static noinline int replay_dir_deletes(struct walk_control *wc, + u64 dirid, bool del_all) +{ + struct btrfs_root *root = wc->root; + struct btrfs_root *log = (del_all ? NULL : wc->log); + u64 range_start; + u64 range_end; + int ret = 0; + struct btrfs_key dir_key; + struct btrfs_key found_key; + BTRFS_PATH_AUTO_FREE(log_path); + struct btrfs_inode *dir; + + dir_key.objectid = dirid; + dir_key.type = BTRFS_DIR_INDEX_KEY; + log_path = btrfs_alloc_path(); + if (!log_path) { + btrfs_abort_log_replay(wc, -ENOMEM, "failed to allocate path"); + return -ENOMEM; + } + + dir = btrfs_iget_logging(dirid, root); + /* + * It isn't an error if the inode isn't there, that can happen because + * we replay the deletes before we copy in the inode item from the log. + */ + if (IS_ERR(dir)) { + ret = PTR_ERR(dir); + if (ret == -ENOENT) + ret = 0; + else + btrfs_abort_log_replay(wc, ret, + "failed to lookup dir inode %llu root %llu", + dirid, btrfs_root_id(root)); + return ret; + } + + range_start = 0; + range_end = 0; + while (1) { + if (del_all) + range_end = (u64)-1; + else { + ret = find_dir_range(log, wc->subvol_path, dirid, + &range_start, &range_end); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to find range for dir %llu in log tree root %llu", + dirid, btrfs_root_id(root)); + goto out; + } else if (ret > 0) { + break; + } + } + + dir_key.offset = range_start; + while (1) { + int nritems; + ret = btrfs_search_slot(NULL, root, &dir_key, + wc->subvol_path, 0, 0); + if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to search root %llu for key " BTRFS_KEY_FMT, + btrfs_root_id(root), + BTRFS_KEY_FMT_VALUE(&dir_key)); + goto out; + } + + nritems = btrfs_header_nritems(wc->subvol_path->nodes[0]); + if (wc->subvol_path->slots[0] >= nritems) { + ret = btrfs_next_leaf(root, wc->subvol_path); + if (ret == 1) { + break; + } else if (ret < 0) { + btrfs_abort_log_replay(wc, ret, + "failed to get next leaf in subvolume root %llu", + btrfs_root_id(root)); + goto out; + } + } + btrfs_item_key_to_cpu(wc->subvol_path->nodes[0], &found_key, + wc->subvol_path->slots[0]); + if (found_key.objectid != dirid || + found_key.type != dir_key.type) { + ret = 0; + goto out; + } + + if (found_key.offset > range_end) + break; + + ret = check_item_in_log(wc, log_path, dir, &found_key, del_all); + if (ret) + goto out; + if (found_key.offset == (u64)-1) + break; + dir_key.offset = found_key.offset + 1; + } + btrfs_release_path(wc->subvol_path); + if (range_end == (u64)-1) + break; + range_start = range_end + 1; + } + ret = 0; +out: + btrfs_release_path(wc->subvol_path); + iput(&dir->vfs_inode); + return ret; +} + +/* + * the process_func used to replay items from the log tree. This + * gets called in two different stages. The first stage just looks + * for inodes and makes sure they are all copied into the subvolume. + * + * The second stage copies all the other item types from the log into + * the subvolume. The two stage approach is slower, but gets rid of + * lots of complexity around inodes referencing other inodes that exist + * only in the log (references come from either directory items or inode + * back refs). + */ +static int replay_one_buffer(struct extent_buffer *eb, + struct walk_control *wc, u64 gen, int level) +{ + int nritems; + struct btrfs_tree_parent_check check = { + .transid = gen, + .level = level + }; + struct btrfs_root *root = wc->root; + struct btrfs_trans_handle *trans = wc->trans; + int ret; + + if (level != 0) + return 0; + + /* + * Set to NULL since it was not yet read and in case we abort log replay + * on error, we have no valid log tree leaf to dump. + */ + wc->log_leaf = NULL; + ret = btrfs_read_extent_buffer(eb, &check); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to read log tree leaf %llu for root %llu", + eb->start, btrfs_root_id(root)); + return ret; + } + + ASSERT(wc->subvol_path == NULL); + wc->subvol_path = btrfs_alloc_path(); + if (!wc->subvol_path) { + btrfs_abort_log_replay(wc, -ENOMEM, "failed to allocate path"); + return -ENOMEM; + } + + wc->log_leaf = eb; + + nritems = btrfs_header_nritems(eb); + for (wc->log_slot = 0; wc->log_slot < nritems; wc->log_slot++) { + struct btrfs_inode_item *inode_item = NULL; + + btrfs_item_key_to_cpu(eb, &wc->log_key, wc->log_slot); + + if (wc->log_key.type == BTRFS_INODE_ITEM_KEY) { + inode_item = btrfs_item_ptr(eb, wc->log_slot, + struct btrfs_inode_item); + /* + * An inode with no links is either: + * + * 1) A tmpfile (O_TMPFILE) that got fsync'ed and never + * got linked before the fsync, skip it, as replaying + * it is pointless since it would be deleted later. + * We skip logging tmpfiles, but it's always possible + * we are replaying a log created with a kernel that + * used to log tmpfiles; + * + * 2) A non-tmpfile which got its last link deleted + * while holding an open fd on it and later got + * fsynced through that fd. We always log the + * parent inodes when inode->last_unlink_trans is + * set to the current transaction, so ignore all the + * inode items for this inode. We will delete the + * inode when processing the parent directory with + * replay_dir_deletes(). + */ + if (btrfs_inode_nlink(eb, inode_item) == 0) { + wc->ignore_cur_inode = true; + continue; + } else { + wc->ignore_cur_inode = false; + } + } + + /* Inode keys are done during the first stage. */ + if (wc->log_key.type == BTRFS_INODE_ITEM_KEY && + wc->stage == LOG_WALK_REPLAY_INODES) { + u32 mode; + + ret = replay_xattr_deletes(wc); + if (ret) + break; + mode = btrfs_inode_mode(eb, inode_item); + if (S_ISDIR(mode)) { + ret = replay_dir_deletes(wc, wc->log_key.objectid, false); + if (ret) + break; + } + ret = overwrite_item(wc); + if (ret) + break; + + /* + * Before replaying extents, truncate the inode to its + * size. We need to do it now and not after log replay + * because before an fsync we can have prealloc extents + * added beyond the inode's i_size. If we did it after, + * through orphan cleanup for example, we would drop + * those prealloc extents just after replaying them. + */ + if (S_ISREG(mode)) { + struct btrfs_drop_extents_args drop_args = { 0 }; + struct btrfs_inode *inode; + u64 from; + + inode = btrfs_iget_logging(wc->log_key.objectid, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + btrfs_abort_log_replay(wc, ret, + "failed to lookup inode %llu root %llu", + wc->log_key.objectid, + btrfs_root_id(root)); + break; + } + from = ALIGN(i_size_read(&inode->vfs_inode), + root->fs_info->sectorsize); + drop_args.start = from; + drop_args.end = (u64)-1; + drop_args.drop_cache = true; + drop_args.path = wc->subvol_path; + ret = btrfs_drop_extents(trans, root, inode, &drop_args); + if (ret) { + btrfs_abort_log_replay(wc, ret, + "failed to drop extents for inode %llu root %llu offset %llu", + btrfs_ino(inode), + btrfs_root_id(root), + from); + } else { + inode_sub_bytes(&inode->vfs_inode, + drop_args.bytes_found); + /* Update the inode's nbytes. */ + ret = btrfs_update_inode(trans, inode); + if (ret) + btrfs_abort_log_replay(wc, ret, + "failed to update inode %llu root %llu", + btrfs_ino(inode), + btrfs_root_id(root)); + } + iput(&inode->vfs_inode); + if (ret) + break; + } + + ret = link_to_fixup_dir(wc, wc->log_key.objectid); + if (ret) + break; + } + + if (wc->ignore_cur_inode) + continue; + + if (wc->log_key.type == BTRFS_DIR_INDEX_KEY && + wc->stage == LOG_WALK_REPLAY_DIR_INDEX) { + ret = replay_one_dir_item(wc); + if (ret) + break; + } + + if (wc->stage < LOG_WALK_REPLAY_ALL) + continue; + + /* these keys are simply copied */ + if (wc->log_key.type == BTRFS_XATTR_ITEM_KEY) { + ret = overwrite_item(wc); + if (ret) + break; + } else if (wc->log_key.type == BTRFS_INODE_REF_KEY || + wc->log_key.type == BTRFS_INODE_EXTREF_KEY) { + ret = add_inode_ref(wc); + if (ret) + break; + } else if (wc->log_key.type == BTRFS_EXTENT_DATA_KEY) { + ret = replay_one_extent(wc); + if (ret) + break; + } + /* + * We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the + * BTRFS_DIR_INDEX_KEY items which we use to derive the + * BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an + * older kernel with such keys, ignore them. + */ + } + btrfs_free_path(wc->subvol_path); + wc->subvol_path = NULL; + return ret; +} + +static int clean_log_buffer(struct btrfs_trans_handle *trans, + struct extent_buffer *eb) +{ + struct btrfs_fs_info *fs_info = eb->fs_info; + struct btrfs_block_group *bg; + + btrfs_tree_lock(eb); + btrfs_clear_buffer_dirty(trans, eb); + wait_on_extent_buffer_writeback(eb); + btrfs_tree_unlock(eb); + + if (trans) { + int ret; + + ret = btrfs_pin_reserved_extent(trans, eb); + if (ret) + btrfs_abort_transaction(trans, ret); + return ret; + } + + bg = btrfs_lookup_block_group(fs_info, eb->start); + if (!bg) { + btrfs_err(fs_info, "unable to find block group for %llu", eb->start); + btrfs_handle_fs_error(fs_info, -ENOENT, NULL); + return -ENOENT; + } + + spin_lock(&bg->space_info->lock); + spin_lock(&bg->lock); + bg->reserved -= fs_info->nodesize; + bg->space_info->bytes_reserved -= fs_info->nodesize; + spin_unlock(&bg->lock); + spin_unlock(&bg->space_info->lock); + + btrfs_put_block_group(bg); + + return 0; +} + +static noinline int walk_down_log_tree(struct btrfs_path *path, int *level, + struct walk_control *wc) +{ + struct btrfs_trans_handle *trans = wc->trans; + struct btrfs_fs_info *fs_info = wc->log->fs_info; + struct btrfs_eb_prealloc pa = { 0 }; + u64 bytenr; + u64 ptr_gen; + struct extent_buffer *next; + struct extent_buffer *cur; + int ret = 0; + + while (*level > 0) { + struct btrfs_tree_parent_check check = { 0 }; + + cur = path->nodes[*level]; + + WARN_ON(btrfs_header_level(cur) != *level); + + if (path->slots[*level] >= + btrfs_header_nritems(cur)) + break; + + bytenr = btrfs_node_blockptr(cur, path->slots[*level]); + ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); + check.transid = ptr_gen; + check.level = *level - 1; + check.has_first_key = true; + btrfs_node_key_to_cpu(cur, &check.first_key, path->slots[*level]); + + next = btrfs_find_create_tree_block(fs_info, &pa, bytenr, + btrfs_header_owner(cur), + *level - 1); + if (IS_ERR(next)) { + ret = PTR_ERR(next); + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(fs_info, ret, NULL); + return ret; + } + + if (*level == 1) { + ret = wc->process_func(next, wc, ptr_gen, *level - 1); + if (ret) { + free_extent_buffer(next); + return ret; + } + + path->slots[*level]++; + if (wc->free) { + ret = btrfs_read_extent_buffer(next, &check); + if (ret) { + free_extent_buffer(next); + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(fs_info, ret, NULL); + return ret; + } + + ret = clean_log_buffer(trans, next); + if (ret) { + free_extent_buffer(next); + return ret; + } + } + free_extent_buffer(next); + continue; + } + ret = btrfs_read_extent_buffer(next, &check); + if (ret) { + free_extent_buffer(next); + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(fs_info, ret, NULL); + return ret; + } + + if (path->nodes[*level-1]) + free_extent_buffer(path->nodes[*level-1]); + path->nodes[*level-1] = next; + *level = btrfs_header_level(next); + path->slots[*level] = 0; + cond_resched(); + } + path->slots[*level] = btrfs_header_nritems(path->nodes[*level]); + + cond_resched(); + return 0; +} + +static noinline int walk_up_log_tree(struct btrfs_path *path, int *level, + struct walk_control *wc) +{ + int i; + int slot; + int ret; + + for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { + slot = path->slots[i]; + if (slot + 1 < btrfs_header_nritems(path->nodes[i])) { + path->slots[i]++; + *level = i; + WARN_ON(*level == 0); + return 0; + } else { + ret = wc->process_func(path->nodes[*level], wc, + btrfs_header_generation(path->nodes[*level]), + *level); + if (ret) + return ret; + + if (wc->free) { + ret = clean_log_buffer(wc->trans, path->nodes[*level]); + if (ret) + return ret; + } + free_extent_buffer(path->nodes[*level]); + path->nodes[*level] = NULL; + *level = i + 1; + } + } + return 1; +} + +/* + * drop the reference count on the tree rooted at 'snap'. This traverses + * the tree freeing any blocks that have a ref count of zero after being + * decremented. + */ +static int walk_log_tree(struct walk_control *wc) +{ + struct btrfs_root *log = wc->log; + int ret = 0; + int wret; + int level; + BTRFS_PATH_AUTO_FREE(path); + int orig_level; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + level = btrfs_header_level(log->node); + orig_level = level; + path->nodes[level] = log->node; + refcount_inc(&log->node->refs); + path->slots[level] = 0; + + while (1) { + wret = walk_down_log_tree(path, &level, wc); + if (wret > 0) + break; + if (wret < 0) + return wret; + + wret = walk_up_log_tree(path, &level, wc); + if (wret > 0) + break; + if (wret < 0) + return wret; + } + + /* was the root node processed? if not, catch it here */ + if (path->nodes[orig_level]) { + ret = wc->process_func(path->nodes[orig_level], wc, + btrfs_header_generation(path->nodes[orig_level]), + orig_level); + if (ret) + return ret; + if (wc->free) + ret = clean_log_buffer(wc->trans, path->nodes[orig_level]); + } + + return ret; +} + +/* + * helper function to update the item for a given subvolumes log root + * in the tree of log roots + */ +static int update_log_root(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_root_item *root_item) +{ + struct btrfs_fs_info *fs_info = log->fs_info; + int ret; + + if (log->log_transid == 1) { + /* insert root item on the first sync */ + ret = btrfs_insert_root(trans, fs_info->log_root_tree, + &log->root_key, root_item); + } else { + ret = btrfs_update_root(trans, fs_info->log_root_tree, + &log->root_key, root_item); + } + return ret; +} + +/* Returns true if we had to wait, false otherwise. */ +static bool wait_log_commit(struct btrfs_root *root, int transid) +{ + DEFINE_WAIT(wait); + const int index = (transid >= 0 ? transid % 2 : -transid % 2); + + if (!root->log_commit[index]) + return false; + + /* + * we only allow two pending log transactions at a time, + * so we know that if ours is more than 2 older than the + * current transaction, we're done + */ + for (;;) { + prepare_to_wait(&root->log_commit_wait[index], + &wait, TASK_UNINTERRUPTIBLE); + + mutex_unlock(&root->log_mutex); + schedule(); + mutex_lock(&root->log_mutex); + + if (!(root->log_transid_committed < transid && + root->log_commit[index])) + break; + } + finish_wait(&root->log_commit_wait[index], &wait); + + return true; +} + +static void wait_for_writer(struct btrfs_root *root) +{ + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait(&root->log_writer_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (!atomic_read(&root->log_writers)) + break; + + mutex_unlock(&root->log_mutex); + schedule(); + mutex_lock(&root->log_mutex); + } + finish_wait(&root->log_writer_wait, &wait); +} + +void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx, struct btrfs_inode *inode) +{ + ctx->log_ret = 0; + ctx->log_transid = 0; + ctx->log_new_dentries = false; + ctx->logging_new_name = false; + ctx->logging_new_delayed_dentries = false; + ctx->logged_before = false; + ctx->inode = inode; + INIT_LIST_HEAD(&ctx->list); + INIT_LIST_HEAD(&ctx->ordered_extents); + INIT_LIST_HEAD(&ctx->conflict_inodes); + ctx->num_conflict_inodes = 0; + ctx->logging_conflict_inodes = false; + ctx->scratch_eb = NULL; +} + +void btrfs_init_log_ctx_scratch_eb(struct btrfs_log_ctx *ctx) +{ + struct btrfs_inode *inode = ctx->inode; + + if (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) && + !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags)) + return; + + /* + * Don't care about allocation failure. This is just for optimization, + * if we fail to allocate here, we will try again later if needed. + */ + ctx->scratch_eb = alloc_dummy_extent_buffer(inode->root->fs_info, 0); +} + +void btrfs_release_log_ctx_extents(struct btrfs_log_ctx *ctx) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_ordered_extent *tmp; + + btrfs_assert_inode_locked(ctx->inode); + + list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) { + list_del_init(&ordered->log_list); + btrfs_put_ordered_extent(ordered); + } +} + + +static inline void btrfs_remove_log_ctx(struct btrfs_root *root, + struct btrfs_log_ctx *ctx) +{ + mutex_lock(&root->log_mutex); + list_del_init(&ctx->list); + mutex_unlock(&root->log_mutex); +} + +/* + * Invoked in log mutex context, or be sure there is no other task which + * can access the list. + */ +static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root, + int index, int error) +{ + struct btrfs_log_ctx *ctx; + struct btrfs_log_ctx *safe; + + list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) { + list_del_init(&ctx->list); + ctx->log_ret = error; + } +} + +/* + * Sends a given tree log down to the disk and updates the super blocks to + * record it. When this call is done, you know that any inodes previously + * logged are safely on disk only if it returns 0. + * + * Any other return value means you need to call btrfs_commit_transaction. + * Some of the edge cases for fsyncing directories that have had unlinks + * or renames done in the past mean that sometimes the only safe + * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN, + * that has happened. + */ +int btrfs_sync_log(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_log_ctx *ctx) +{ + int mark; + int ret; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_root *log = root->log_root; + struct btrfs_root *log_root_tree = fs_info->log_root_tree; + struct btrfs_root_item new_root_item; + int log_transid = ctx->log_transid; + int index1 = log_transid % 2; + int index2; + struct btrfs_log_ctx root_log_ctx; + struct blk_plug plug; + u64 log_root_start; + u64 log_root_level; + + mutex_lock(&root->log_mutex); + trace_btrfs_sync_log_enter(trans, root, ctx); + if (root->log_transid_committed >= log_transid) { + trace_btrfs_sync_log_exit(trans, root, ctx, ctx->log_ret); + mutex_unlock(&root->log_mutex); + return ctx->log_ret; + } + + if (wait_log_commit(root, log_transid)) { + trace_btrfs_sync_log_exit(trans, root, ctx, ctx->log_ret); + mutex_unlock(&root->log_mutex); + return ctx->log_ret; + } + ASSERT(log_transid == root->log_transid, + "log_transid=%d root->log_transid=%d", log_transid, root->log_transid); + root->log_commit[index1] = true; + + /* wait for previous tree log sync to complete */ + wait_log_commit(root, log_transid - 1); + + wait_for_writer(root); + + /* bail out if we need to do a full commit */ + if (btrfs_need_log_full_commit(trans)) { + ret = BTRFS_LOG_FORCE_COMMIT; + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + mutex_unlock(&root->log_mutex); + goto out; + } + + if (log_transid % 2 == 0) + mark = EXTENT_DIRTY_LOG1; + else + mark = EXTENT_DIRTY_LOG2; + + /* we start IO on all the marked extents here, but we don't actually + * wait for them until later. + */ + blk_start_plug(&plug); + ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark); + /* + * -EAGAIN happens when someone, e.g., a concurrent transaction + * commit, writes a dirty extent in this tree-log commit. This + * concurrent write will create a hole writing out the extents, + * and we cannot proceed on a zoned filesystem, requiring + * sequential writing. While we can bail out to a full commit + * here, but we can continue hoping the concurrent writing fills + * the hole. + */ + if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) + ret = 0; + if (ret) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + blk_finish_plug(&plug); + btrfs_set_log_full_commit(trans); + mutex_unlock(&root->log_mutex); + goto out; + } + + /* + * We _must_ update under the root->log_mutex in order to make sure we + * have a consistent view of the log root we are trying to commit at + * this moment. + * + * We _must_ copy this into a local copy, because we are not holding the + * log_root_tree->log_mutex yet. This is important because when we + * commit the log_root_tree we must have a consistent view of the + * log_root_tree when we update the super block to point at the + * log_root_tree bytenr. If we update the log_root_tree here we'll race + * with the commit and possibly point at the new block which we may not + * have written out. + */ + btrfs_set_root_node(&log->root_item, log->node); + memcpy(&new_root_item, &log->root_item, sizeof(new_root_item)); + + btrfs_set_root_log_transid(root, root->log_transid + 1); + log->log_transid = root->log_transid; + /* + * IO has been started, blocks of the log tree have WRITTEN flag set + * in their headers. new modifications of the log will be written to + * new positions. so it's safe to allow log writers to go in. + */ + mutex_unlock(&root->log_mutex); + + if (btrfs_is_zoned(fs_info)) { + mutex_lock(&fs_info->tree_root->log_mutex); + if (!log_root_tree->node) { + ret = btrfs_alloc_log_tree_node(trans, log_root_tree); + if (ret) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + mutex_unlock(&fs_info->tree_root->log_mutex); + blk_finish_plug(&plug); + goto out; + } + } + mutex_unlock(&fs_info->tree_root->log_mutex); + } + + btrfs_init_log_ctx(&root_log_ctx, NULL); + + mutex_lock(&log_root_tree->log_mutex); + + index2 = log_root_tree->log_transid % 2; + list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]); + root_log_ctx.log_transid = log_root_tree->log_transid; + + /* + * Now we are safe to update the log_root_tree because we're under the + * log_mutex, and we're a current writer so we're holding the commit + * open until we drop the log_mutex. + */ + ret = update_log_root(trans, log, &new_root_item); + if (ret) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + list_del_init(&root_log_ctx.list); + blk_finish_plug(&plug); + btrfs_set_log_full_commit(trans); + if (ret != -ENOSPC) + btrfs_err(fs_info, + "failed to update log for root %llu ret %d", + btrfs_root_id(root), ret); + btrfs_wait_tree_log_extents(log, mark); + mutex_unlock(&log_root_tree->log_mutex); + goto out; + } + + if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) { + blk_finish_plug(&plug); + list_del_init(&root_log_ctx.list); + mutex_unlock(&log_root_tree->log_mutex); + ret = root_log_ctx.log_ret; + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + goto out; + } + + if (log_root_tree->log_commit[index2]) { + blk_finish_plug(&plug); + ret = btrfs_wait_tree_log_extents(log, mark); + wait_log_commit(log_root_tree, + root_log_ctx.log_transid); + mutex_unlock(&log_root_tree->log_mutex); + if (!ret) + ret = root_log_ctx.log_ret; + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + goto out; + } + ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid, + "root_log_ctx.log_transid=%d log_root_tree->log_transid=%d", + root_log_ctx.log_transid, log_root_tree->log_transid); + log_root_tree->log_commit[index2] = true; + + wait_log_commit(log_root_tree, root_log_ctx.log_transid - 1); + + /* + * now that we've moved on to the tree of log tree roots, + * check the full commit flag again + */ + if (btrfs_need_log_full_commit(trans)) { + blk_finish_plug(&plug); + btrfs_wait_tree_log_extents(log, mark); + mutex_unlock(&log_root_tree->log_mutex); + ret = BTRFS_LOG_FORCE_COMMIT; + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + goto out_wake_log_root; + } + + ret = btrfs_write_marked_extents(fs_info, + &log_root_tree->dirty_log_pages, + EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2); + blk_finish_plug(&plug); + /* + * As described above, -EAGAIN indicates a hole in the extents. We + * cannot wait for these write outs since the waiting cause a + * deadlock. Bail out to the full commit instead. + */ + if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + btrfs_set_log_full_commit(trans); + btrfs_wait_tree_log_extents(log, mark); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } else if (ret) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + btrfs_set_log_full_commit(trans); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + ret = btrfs_wait_tree_log_extents(log, mark); + if (!ret) + ret = btrfs_wait_tree_log_extents(log_root_tree, + EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2); + if (ret) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + btrfs_set_log_full_commit(trans); + mutex_unlock(&log_root_tree->log_mutex); + goto out_wake_log_root; + } + + log_root_start = log_root_tree->node->start; + log_root_level = btrfs_header_level(log_root_tree->node); + log_root_tree->log_transid++; + mutex_unlock(&log_root_tree->log_mutex); + + /* + * Here we are guaranteed that nobody is going to write the superblock + * for the current transaction before us and that neither we do write + * our superblock before the previous transaction finishes its commit + * and writes its superblock, because: + * + * 1) We are holding a handle on the current transaction, so no body + * can commit it until we release the handle; + * + * 2) Before writing our superblock we acquire the tree_log_mutex, so + * if the previous transaction is still committing, and hasn't yet + * written its superblock, we wait for it to do it, because a + * transaction commit acquires the tree_log_mutex when the commit + * begins and releases it only after writing its superblock. + */ + mutex_lock(&fs_info->tree_log_mutex); + + /* + * The previous transaction writeout phase could have failed, and thus + * marked the fs in an error state. We must not commit here, as we + * could have updated our generation in the super_for_commit and + * writing the super here would result in transid mismatches. If there + * is an error here just bail. + */ + if (unlikely(BTRFS_FS_ERROR(fs_info))) { + ret = -EIO; + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + btrfs_set_log_full_commit(trans); + btrfs_abort_transaction(trans, ret); + mutex_unlock(&fs_info->tree_log_mutex); + goto out_wake_log_root; + } + + btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start); + btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level); + ret = write_all_supers(trans); + mutex_unlock(&fs_info->tree_log_mutex); + if (unlikely(ret)) { + trace_btrfs_sync_log_exit(trans, root, ctx, ret); + btrfs_set_log_full_commit(trans); + btrfs_abort_transaction(trans, ret); + goto out_wake_log_root; + } + + /* + * We know there can only be one task here, since we have not yet set + * root->log_commit[index1] to false and any task attempting to sync the + * log must wait for the previous log transaction to commit if it's + * still in progress or wait for the current log transaction commit if + * someone else already started it. We use <= and not < because the + * first log transaction has an ID of 0. + */ + ASSERT(btrfs_get_root_last_log_commit(root) <= log_transid, + "last_log_commit(root)=%d log_transid=%d", + btrfs_get_root_last_log_commit(root), log_transid); + btrfs_set_root_last_log_commit(root, log_transid); + +out_wake_log_root: + mutex_lock(&log_root_tree->log_mutex); + btrfs_remove_all_log_ctxs(log_root_tree, index2, ret); + + log_root_tree->log_transid_committed++; + log_root_tree->log_commit[index2] = false; + mutex_unlock(&log_root_tree->log_mutex); + + /* + * The barrier before waitqueue_active (in cond_wake_up) is needed so + * all the updates above are seen by the woken threads. It might not be + * necessary, but proving that seems to be hard. + */ + cond_wake_up(&log_root_tree->log_commit_wait[index2]); +out: + mutex_lock(&root->log_mutex); + btrfs_remove_all_log_ctxs(root, index1, ret); + root->log_transid_committed++; + root->log_commit[index1] = false; + mutex_unlock(&root->log_mutex); + + /* + * The barrier before waitqueue_active (in cond_wake_up) is needed so + * all the updates above are seen by the woken threads. It might not be + * necessary, but proving that seems to be hard. + */ + cond_wake_up(&root->log_commit_wait[index1]); + return ret; +} + +static void free_log_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *log) +{ + int ret; + struct walk_control wc = { + .free = true, + .process_func = process_one_buffer, + .log = log, + .trans = trans, + }; + + if (log->node) { + ret = walk_log_tree(&wc); + if (ret) { + /* + * We weren't able to traverse the entire log tree, the + * typical scenario is getting an -EIO when reading an + * extent buffer of the tree, due to a previous writeback + * failure of it. + */ + set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR, + &log->fs_info->fs_state); + + /* + * Some extent buffers of the log tree may still be dirty + * and not yet written back to storage, because we may + * have updates to a log tree without syncing a log tree, + * such as during rename and link operations. So flush + * them out and wait for their writeback to complete, so + * that we properly cleanup their state and pages. + */ + btrfs_write_marked_extents(log->fs_info, + &log->dirty_log_pages, + EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2); + btrfs_wait_tree_log_extents(log, + EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2); + + if (trans) + btrfs_abort_transaction(trans, ret); + else + btrfs_handle_fs_error(log->fs_info, ret, NULL); + } + } + + btrfs_extent_io_tree_release(&log->dirty_log_pages); + btrfs_extent_io_tree_release(&log->log_csum_range); + + btrfs_put_root(log); +} + +/* + * free all the extents used by the tree log. This should be called + * at commit time of the full transaction + */ +void btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root) +{ + if (root->log_root) { + free_log_tree(trans, root->log_root); + root->log_root = NULL; + clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state); + } +} + +void btrfs_free_log_root_tree(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info) +{ + if (fs_info->log_root_tree) { + free_log_tree(trans, fs_info->log_root_tree); + fs_info->log_root_tree = NULL; + clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state); + } +} + +static bool mark_inode_as_not_logged(const struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + bool ret = false; + + /* + * Do this only if ->logged_trans is still 0 to prevent races with + * concurrent logging as we may see the inode not logged when + * inode_logged() is called but it gets logged after inode_logged() did + * not find it in the log tree and we end up setting ->logged_trans to a + * value less than trans->transid after the concurrent logging task has + * set it to trans->transid. As a consequence, subsequent rename, unlink + * and link operations may end up not logging new names and removing old + * names from the log. + */ + spin_lock(&inode->lock); + if (inode->logged_trans == 0) + inode->logged_trans = trans->transid - 1; + else if (inode->logged_trans == trans->transid) + ret = true; + spin_unlock(&inode->lock); + + return ret; +} + +/* + * Check if an inode was logged in the current transaction. This correctly deals + * with the case where the inode was logged but has a logged_trans of 0, which + * happens if the inode is evicted and loaded again, as logged_trans is an in + * memory only field (not persisted). + * + * Returns 1 if the inode was logged before in the transaction, 0 if it was not, + * and < 0 on error. + */ +static int inode_logged(const struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path_in) +{ + struct btrfs_path *path = path_in; + struct btrfs_key key; + int ret; + + /* + * Quick lockless call, since once ->logged_trans is set to the current + * transaction, we never set it to a lower value anywhere else. + */ + if (data_race(inode->logged_trans) == trans->transid) + return 1; + + /* + * If logged_trans is not 0 and not trans->transid, then we know the + * inode was not logged in this transaction, so we can return false + * right away. We take the lock to avoid a race caused by load/store + * tearing with a concurrent btrfs_log_inode() call or a concurrent task + * in this function further below - an update to trans->transid can be + * teared into two 32 bits updates for example, in which case we could + * see a positive value that is not trans->transid and assume the inode + * was not logged when it was. + */ + spin_lock(&inode->lock); + if (inode->logged_trans == trans->transid) { + spin_unlock(&inode->lock); + return 1; + } else if (inode->logged_trans > 0) { + spin_unlock(&inode->lock); + return 0; + } + spin_unlock(&inode->lock); + + /* + * If no log tree was created for this root in this transaction, then + * the inode can not have been logged in this transaction. In that case + * set logged_trans to anything greater than 0 and less than the current + * transaction's ID, to avoid the search below in a future call in case + * a log tree gets created after this. + */ + if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) + return mark_inode_as_not_logged(trans, inode); + + /* + * We have a log tree and the inode's logged_trans is 0. We can't tell + * for sure if the inode was logged before in this transaction by looking + * only at logged_trans. We could be pessimistic and assume it was, but + * that can lead to unnecessarily logging an inode during rename and link + * operations, and then further updating the log in followup rename and + * link operations, specially if it's a directory, which adds latency + * visible to applications doing a series of rename or link operations. + * + * A logged_trans of 0 here can mean several things: + * + * 1) The inode was never logged since the filesystem was mounted, and may + * or may have not been evicted and loaded again; + * + * 2) The inode was logged in a previous transaction, then evicted and + * then loaded again; + * + * 3) The inode was logged in the current transaction, then evicted and + * then loaded again. + * + * For cases 1) and 2) we don't want to return true, but we need to detect + * case 3) and return true. So we do a search in the log root for the inode + * item. + */ + key.objectid = btrfs_ino(inode); + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + if (!path) { + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + } + + ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0); + + if (path_in) + btrfs_release_path(path); + else + btrfs_free_path(path); + + /* + * Logging an inode always results in logging its inode item. So if we + * did not find the item we know the inode was not logged for sure. + */ + if (ret < 0) { + return ret; + } else if (ret > 0) { + /* + * Set logged_trans to a value greater than 0 and less then the + * current transaction to avoid doing the search in future calls. + */ + return mark_inode_as_not_logged(trans, inode); + } + + /* + * The inode was previously logged and then evicted, set logged_trans to + * the current transaction's ID, to avoid future tree searches as long as + * the inode is not evicted again. + */ + spin_lock(&inode->lock); + inode->logged_trans = trans->transid; + spin_unlock(&inode->lock); + + return 1; +} + +/* + * Delete a directory entry from the log if it exists. + * + * Returns < 0 on error + * 1 if the entry does not exists + * 0 if the entry existed and was successfully deleted + */ +static int del_logged_dentry(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + u64 dir_ino, + const struct fscrypt_str *name, + u64 index) +{ + struct btrfs_dir_item *di; + + /* + * We only log dir index items of a directory, so we don't need to look + * for dir item keys. + */ + di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino, + index, name, -1); + if (IS_ERR(di)) + return PTR_ERR(di); + else if (!di) + return 1; + + /* + * We do not need to update the size field of the directory's + * inode item because on log replay we update the field to reflect + * all existing entries in the directory (see overwrite_item()). + */ + return btrfs_del_item(trans, log, path); +} + +/* + * If both a file and directory are logged, and unlinks or renames are + * mixed in, we have a few interesting corners: + * + * create file X in dir Y + * link file X to X.link in dir Y + * fsync file X + * unlink file X but leave X.link + * fsync dir Y + * + * After a crash we would expect only X.link to exist. But file X + * didn't get fsync'd again so the log has back refs for X and X.link. + * + * We solve this by removing directory entries and inode backrefs from the + * log when a file that was logged in the current transaction is + * unlinked. Any later fsync will include the updated log entries, and + * we'll be able to reconstruct the proper directory items from backrefs. + * + * This optimizations allows us to avoid relogging the entire inode + * or the entire directory. + */ +void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans, + const struct fscrypt_str *name, + struct btrfs_inode *dir, u64 index) +{ + struct btrfs_root *root = dir->root; + BTRFS_PATH_AUTO_FREE(path); + int ret; + + ret = inode_logged(trans, dir, NULL); + if (ret == 0) + return; + if (ret < 0) { + btrfs_set_log_full_commit(trans); + return; + } + + path = btrfs_alloc_path(); + if (!path) { + btrfs_set_log_full_commit(trans); + return; + } + + ret = join_running_log_trans(root); + ASSERT(ret == 0, "join_running_log_trans() ret=%d", ret); + if (WARN_ON(ret)) + return; + + mutex_lock(&dir->log_mutex); + + ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir), + name, index); + mutex_unlock(&dir->log_mutex); + if (ret < 0) + btrfs_set_log_full_commit(trans); + btrfs_end_log_trans(root); +} + +/* see comments for btrfs_del_dir_entries_in_log */ +void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans, + const struct fscrypt_str *name, + struct btrfs_inode *inode, + struct btrfs_inode *dir) +{ + struct btrfs_root *root = dir->root; + int ret; + + ret = inode_logged(trans, inode, NULL); + if (ret == 0) + return; + else if (ret < 0) { + btrfs_set_log_full_commit(trans); + return; + } + + ret = join_running_log_trans(root); + ASSERT(ret == 0, "join_running_log_trans() ret=%d", ret); + if (WARN_ON(ret)) + return; + mutex_lock(&inode->log_mutex); + + ret = btrfs_del_inode_ref(trans, root->log_root, name, btrfs_ino(inode), + btrfs_ino(dir), NULL); + mutex_unlock(&inode->log_mutex); + if (ret < 0 && ret != -ENOENT) + btrfs_set_log_full_commit(trans); + btrfs_end_log_trans(root); +} + +/* + * creates a range item in the log for 'dirid'. first_offset and + * last_offset tell us which parts of the key space the log should + * be considered authoritative for. + */ +static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + u64 dirid, + u64 first_offset, u64 last_offset) +{ + int ret; + struct btrfs_key key; + struct btrfs_dir_log_item *item; + + key.objectid = dirid; + key.type = BTRFS_DIR_LOG_INDEX_KEY; + key.offset = first_offset; + ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item)); + /* + * -EEXIST is fine and can happen sporadically when we are logging a + * directory and have concurrent insertions in the subvolume's tree for + * items from other inodes and that result in pushing off some dir items + * from one leaf to another in order to accommodate for the new items. + * This results in logging the same dir index range key. + */ + if (ret && ret != -EEXIST) + return ret; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_dir_log_item); + if (ret == -EEXIST) { + const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item); + + /* + * btrfs_del_dir_entries_in_log() might have been called during + * an unlink between the initial insertion of this key and the + * current update, or we might be logging a single entry deletion + * during a rename, so set the new last_offset to the max value. + */ + last_offset = max(last_offset, curr_end); + } + btrfs_set_dir_log_end(path->nodes[0], item, last_offset); + btrfs_release_path(path); + return 0; +} + +static int flush_dir_items_batch(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct extent_buffer *src, + struct btrfs_path *dst_path, + int start_slot, + int count) +{ + struct btrfs_root *log = inode->root->log_root; + char AUTO_KFREE(ins_data); + struct btrfs_item_batch batch; + struct extent_buffer *dst; + unsigned long src_offset; + unsigned long dst_offset; + u64 last_index; + struct btrfs_key key; + u32 item_size; + int ret; + int i; + + ASSERT(count > 0, "count=%d", count); + batch.nr = count; + + if (count == 1) { + btrfs_item_key_to_cpu(src, &key, start_slot); + item_size = btrfs_item_size(src, start_slot); + batch.keys = &key; + batch.data_sizes = &item_size; + batch.total_data_size = item_size; + } else { + struct btrfs_key *ins_keys; + u32 *ins_sizes; + + ins_data = kmalloc_array(count, sizeof(u32) + sizeof(struct btrfs_key), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + + ins_sizes = (u32 *)ins_data; + ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32)); + batch.keys = ins_keys; + batch.data_sizes = ins_sizes; + batch.total_data_size = 0; + + for (i = 0; i < count; i++) { + const int slot = start_slot + i; + + btrfs_item_key_to_cpu(src, &ins_keys[i], slot); + ins_sizes[i] = btrfs_item_size(src, slot); + batch.total_data_size += ins_sizes[i]; + } + } + + ret = btrfs_insert_empty_items(trans, log, dst_path, &batch); + if (ret) + return ret; + + dst = dst_path->nodes[0]; + /* + * Copy all the items in bulk, in a single copy operation. Item data is + * organized such that it's placed at the end of a leaf and from right + * to left. For example, the data for the second item ends at an offset + * that matches the offset where the data for the first item starts, the + * data for the third item ends at an offset that matches the offset + * where the data of the second items starts, and so on. + * Therefore our source and destination start offsets for copy match the + * offsets of the last items (highest slots). + */ + dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1); + src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1); + copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size); + btrfs_release_path(dst_path); + + last_index = batch.keys[count - 1].offset; + ASSERT(last_index > inode->last_dir_index_offset, + "last_index=%llu inode->last_dir_index_offset=%llu", + last_index, inode->last_dir_index_offset); + + /* + * If for some unexpected reason the last item's index is not greater + * than the last index we logged, warn and force a transaction commit. + */ + if (WARN_ON(last_index <= inode->last_dir_index_offset)) + ret = BTRFS_LOG_FORCE_COMMIT; + else + inode->last_dir_index_offset = last_index; + + if (btrfs_get_first_dir_index_to_log(inode) == 0) + btrfs_set_first_dir_index_to_log(inode, batch.keys[0].offset); + + return ret; +} + +static int clone_leaf(struct btrfs_path *path, struct btrfs_log_ctx *ctx) +{ + const int slot = path->slots[0]; + + if (ctx->scratch_eb) { + copy_extent_buffer_full(ctx->scratch_eb, path->nodes[0]); + } else { + ctx->scratch_eb = btrfs_clone_extent_buffer(path->nodes[0]); + if (!ctx->scratch_eb) + return -ENOMEM; + } + + btrfs_release_path(path); + path->nodes[0] = ctx->scratch_eb; + path->slots[0] = slot; + /* + * Add extra ref to scratch eb so that it is not freed when callers + * release the path, so we can reuse it later if needed. + */ + refcount_inc(&ctx->scratch_eb->refs); + + return 0; +} + +static int process_dir_items_leaf(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path, + struct btrfs_log_ctx *ctx, + u64 *last_old_dentry_offset) +{ + struct btrfs_root *log = inode->root->log_root; + struct extent_buffer *src; + const int nritems = btrfs_header_nritems(path->nodes[0]); + const u64 ino = btrfs_ino(inode); + bool last_found = false; + int batch_start = 0; + int batch_size = 0; + int ret; + + /* + * We need to clone the leaf, release the read lock on it, and use the + * clone before modifying the log tree. See the comment at copy_items() + * about why we need to do this. + */ + ret = clone_leaf(path, ctx); + if (ret < 0) + return ret; + + src = path->nodes[0]; + + for (int i = path->slots[0]; i < nritems; i++) { + struct btrfs_dir_item *di; + struct btrfs_key key; + + btrfs_item_key_to_cpu(src, &key, i); + + if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) { + last_found = true; + break; + } + + di = btrfs_item_ptr(src, i, struct btrfs_dir_item); + + /* + * Skip ranges of items that consist only of dir item keys created + * in past transactions. However if we find a gap, we must log a + * dir index range item for that gap, so that index keys in that + * gap are deleted during log replay. + */ + if (btrfs_dir_transid(src, di) < trans->transid) { + if (key.offset > *last_old_dentry_offset + 1) { + ret = insert_dir_log_key(trans, log, dst_path, + ino, *last_old_dentry_offset + 1, + key.offset - 1); + if (ret < 0) + return ret; + } + + *last_old_dentry_offset = key.offset; + continue; + } + + /* If we logged this dir index item before, we can skip it. */ + if (key.offset <= inode->last_dir_index_offset) + continue; + + /* + * We must make sure that when we log a directory entry, the + * corresponding inode, after log replay, has a matching link + * count. For example: + * + * touch foo + * mkdir mydir + * sync + * ln foo mydir/bar + * xfs_io -c "fsync" mydir + * <crash> + * <mount fs and log replay> + * + * Would result in a fsync log that when replayed, our file inode + * would have a link count of 1, but we get two directory entries + * pointing to the same inode. After removing one of the names, + * it would not be possible to remove the other name, which + * resulted always in stale file handle errors, and would not be + * possible to rmdir the parent directory, since its i_size could + * never be decremented to the value BTRFS_EMPTY_DIR_SIZE, + * resulting in -ENOTEMPTY errors. + */ + if (!ctx->log_new_dentries) { + struct btrfs_key di_key; + + btrfs_dir_item_key_to_cpu(src, di, &di_key); + if (di_key.type != BTRFS_ROOT_ITEM_KEY) + ctx->log_new_dentries = true; + } + + if (batch_size == 0) + batch_start = i; + batch_size++; + } + + if (batch_size > 0) { + ret = flush_dir_items_batch(trans, inode, src, dst_path, + batch_start, batch_size); + if (ret < 0) + return ret; + } + + return last_found ? 1 : 0; +} + +/* + * log all the items included in the current transaction for a given + * directory. This also creates the range items in the log tree required + * to replay anything deleted before the fsync + */ +static noinline int log_dir_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path, + struct btrfs_log_ctx *ctx, + u64 min_offset, u64 *last_offset_ret) +{ + struct btrfs_key min_key; + struct btrfs_root *root = inode->root; + struct btrfs_root *log = root->log_root; + int ret; + u64 last_old_dentry_offset = min_offset - 1; + u64 last_offset = (u64)-1; + u64 ino = btrfs_ino(inode); + + min_key.objectid = ino; + min_key.type = BTRFS_DIR_INDEX_KEY; + min_key.offset = min_offset; + + ret = btrfs_search_forward(root, &min_key, path, trans->transid); + + /* + * we didn't find anything from this transaction, see if there + * is anything at all + */ + if (ret != 0 || min_key.objectid != ino || + min_key.type != BTRFS_DIR_INDEX_KEY) { + min_key.objectid = ino; + min_key.type = BTRFS_DIR_INDEX_KEY; + min_key.offset = (u64)-1; + btrfs_release_path(path); + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (ret < 0) { + btrfs_release_path(path); + return ret; + } + ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY); + + /* if ret == 0 there are items for this type, + * create a range to tell us the last key of this type. + * otherwise, there are no items in this directory after + * *min_offset, and we create a range to indicate that. + */ + if (ret == 0) { + struct btrfs_key tmp; + + btrfs_item_key_to_cpu(path->nodes[0], &tmp, + path->slots[0]); + if (tmp.type == BTRFS_DIR_INDEX_KEY) + last_old_dentry_offset = tmp.offset; + } else if (ret > 0) { + ret = 0; + } + + goto done; + } + + /* go backward to find any previous key */ + ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY); + if (ret == 0) { + struct btrfs_key tmp; + + btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]); + /* + * The dir index key before the first one we found that needs to + * be logged might be in a previous leaf, and there might be a + * gap between these keys, meaning that we had deletions that + * happened. So the key range item we log (key type + * BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the + * previous key's offset plus 1, so that those deletes are replayed. + */ + if (tmp.type == BTRFS_DIR_INDEX_KEY) + last_old_dentry_offset = tmp.offset; + } else if (ret < 0) { + goto done; + } + + btrfs_release_path(path); + + /* + * Find the first key from this transaction again or the one we were at + * in the loop below in case we had to reschedule. We may be logging the + * directory without holding its VFS lock, which happen when logging new + * dentries (through log_new_dir_dentries()) or in some cases when we + * need to log the parent directory of an inode. This means a dir index + * key might be deleted from the inode's root, and therefore we may not + * find it anymore. If we can't find it, just move to the next key. We + * can not bail out and ignore, because if we do that we will simply + * not log dir index keys that come after the one that was just deleted + * and we can end up logging a dir index range that ends at (u64)-1 + * (@last_offset is initialized to that), resulting in removing dir + * entries we should not remove at log replay time. + */ +search: + ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0); + if (ret > 0) { + ret = btrfs_next_item(root, path); + if (ret > 0) { + /* There are no more keys in the inode's root. */ + ret = 0; + goto done; + } + } + if (ret < 0) + goto done; + + /* + * we have a block from this transaction, log every item in it + * from our directory + */ + while (1) { + ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx, + &last_old_dentry_offset); + if (ret != 0) { + if (ret > 0) + ret = 0; + goto done; + } + path->slots[0] = btrfs_header_nritems(path->nodes[0]); + + /* + * look ahead to the next item and see if it is also + * from this directory and from this transaction + */ + ret = btrfs_next_leaf(root, path); + if (ret) { + if (ret == 1) { + last_offset = (u64)-1; + ret = 0; + } + goto done; + } + btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]); + if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) { + last_offset = (u64)-1; + goto done; + } + if (btrfs_header_generation(path->nodes[0]) != trans->transid) { + /* + * The next leaf was not changed in the current transaction + * and has at least one dir index key. + * We check for the next key because there might have been + * one or more deletions between the last key we logged and + * that next key. So the key range item we log (key type + * BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's + * offset minus 1, so that those deletes are replayed. + */ + last_offset = min_key.offset - 1; + goto done; + } + if (need_resched()) { + btrfs_release_path(path); + cond_resched(); + goto search; + } + } +done: + btrfs_release_path(path); + btrfs_release_path(dst_path); + + if (ret == 0) { + *last_offset_ret = last_offset; + /* + * In case the leaf was changed in the current transaction but + * all its dir items are from a past transaction, the last item + * in the leaf is a dir item and there's no gap between that last + * dir item and the first one on the next leaf (which did not + * change in the current transaction), then we don't need to log + * a range, last_old_dentry_offset is == to last_offset. + */ + ASSERT(last_old_dentry_offset <= last_offset, + "last_old_dentry_offset=%llu last_offset=%llu", + last_old_dentry_offset, last_offset); + if (last_old_dentry_offset < last_offset) + ret = insert_dir_log_key(trans, log, path, ino, + last_old_dentry_offset + 1, + last_offset); + } + + return ret; +} + +/* + * If the inode was logged before and it was evicted, then its + * last_dir_index_offset is 0, so we don't know the value of the last index + * key offset. If that's the case, search for it and update the inode. This + * is to avoid lookups in the log tree every time we try to insert a dir index + * key from a leaf changed in the current transaction, and to allow us to always + * do batch insertions of dir index keys. + */ +static int update_last_dir_index_offset(struct btrfs_inode *inode, + struct btrfs_path *path, + const struct btrfs_log_ctx *ctx) +{ + const u64 ino = btrfs_ino(inode); + struct btrfs_key key; + int ret; + + lockdep_assert_held(&inode->log_mutex); + + if (inode->last_dir_index_offset != 0) + return 0; + + if (!ctx->logged_before) { + inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1; + return 0; + } + + key.objectid = ino; + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0); + /* + * An error happened or we actually have an index key with an offset + * value of (u64)-1. Bail out, we're done. + */ + if (ret <= 0) + goto out; + + ret = 0; + inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1; + + /* + * No dir index items, bail out and leave last_dir_index_offset with + * the value right before the first valid index value. + */ + if (path->slots[0] == 0) + goto out; + + /* + * btrfs_search_slot() left us at one slot beyond the slot with the last + * index key, or beyond the last key of the directory that is not an + * index key. If we have an index key before, set last_dir_index_offset + * to its offset value, otherwise leave it with a value right before the + * first valid index value, as it means we have an empty directory. + */ + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1); + if (key.objectid == ino && key.type == BTRFS_DIR_INDEX_KEY) + inode->last_dir_index_offset = key.offset; + +out: + btrfs_release_path(path); + + return ret; +} + +/* + * logging directories is very similar to logging inodes, We find all the items + * from the current transaction and write them to the log. + * + * The recovery code scans the directory in the subvolume, and if it finds a + * key in the range logged that is not present in the log tree, then it means + * that dir entry was unlinked during the transaction. + * + * In order for that scan to work, we must include one key smaller than + * the smallest logged by this transaction and one key larger than the largest + * key logged by this transaction. + */ +static noinline int log_directory_changes(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path, + struct btrfs_log_ctx *ctx) +{ + u64 min_key; + u64 max_key; + int ret; + + ret = update_last_dir_index_offset(inode, path, ctx); + if (ret) + return ret; + + min_key = BTRFS_DIR_START_INDEX; + max_key = 0; + + while (1) { + ret = log_dir_items(trans, inode, path, dst_path, + ctx, min_key, &max_key); + if (ret) + return ret; + if (max_key == (u64)-1) + break; + min_key = max_key + 1; + } + + return 0; +} + +/* + * a helper function to drop items from the log before we relog an + * inode. max_key_type indicates the highest item type to remove. + * This cannot be run for file data extents because it does not + * free the extents they point to. + */ +static int drop_inode_items(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + struct btrfs_inode *inode, + int max_key_type) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + int start_slot; + + key.objectid = btrfs_ino(inode); + key.type = max_key_type; + key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(trans, log, &key, path, -1, 1); + if (ret < 0) { + break; + } else if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + + if (found_key.objectid != key.objectid) + break; + + found_key.offset = 0; + found_key.type = 0; + ret = btrfs_bin_search(path->nodes[0], 0, &found_key, &start_slot); + if (ret < 0) + break; + + ret = btrfs_del_items(trans, log, path, start_slot, + path->slots[0] - start_slot + 1); + /* + * If start slot isn't 0 then we don't need to re-search, we've + * found the last guy with the objectid in this tree. + */ + if (ret || start_slot != 0) + break; + btrfs_release_path(path); + } + btrfs_release_path(path); + if (ret > 0) + ret = 0; + return ret; +} + +static int truncate_inode_items(struct btrfs_trans_handle *trans, + struct btrfs_root *log_root, + struct btrfs_inode *inode, + u64 new_size, u32 min_type) +{ + struct btrfs_truncate_control control = { + .new_size = new_size, + .ino = btrfs_ino(inode), + .min_type = min_type, + .skip_ref_updates = true, + }; + + return btrfs_truncate_inode_items(trans, log_root, &control); +} + +static void fill_inode_item(struct btrfs_trans_handle *trans, + struct extent_buffer *leaf, + struct btrfs_inode_item *item, + struct btrfs_inode *inode, bool log_inode_only, + u64 logged_isize) +{ + struct inode *vfs_inode = &inode->vfs_inode; + u64 gen = inode->generation; + u64 flags; + + if (log_inode_only) { + /* + * Set the generation to zero so the recover code can tell the + * difference between a logging just to say 'this inode exists' + * and a logging to say 'update this inode with these values'. + * But only if the inode was not already logged before. + * We access ->logged_trans directly since it was already set + * up in the call chain by btrfs_log_inode(), and data_race() + * to avoid false alerts from KCSAN and since it was set already + * and one can set it to 0 since that only happens on eviction + * and we are holding a ref on the inode. + */ + ASSERT(data_race(inode->logged_trans) > 0); + if (data_race(inode->logged_trans) < trans->transid) + gen = 0; + + btrfs_set_inode_size(leaf, item, logged_isize); + } else { + btrfs_set_inode_size(leaf, item, vfs_inode->i_size); + } + + btrfs_set_inode_generation(leaf, item, gen); + + btrfs_set_inode_uid(leaf, item, i_uid_read(vfs_inode)); + btrfs_set_inode_gid(leaf, item, i_gid_read(vfs_inode)); + btrfs_set_inode_mode(leaf, item, vfs_inode->i_mode); + btrfs_set_inode_nlink(leaf, item, vfs_inode->i_nlink); + + btrfs_set_timespec_sec(leaf, &item->atime, inode_get_atime_sec(vfs_inode)); + btrfs_set_timespec_nsec(leaf, &item->atime, inode_get_atime_nsec(vfs_inode)); + + btrfs_set_timespec_sec(leaf, &item->mtime, inode_get_mtime_sec(vfs_inode)); + btrfs_set_timespec_nsec(leaf, &item->mtime, inode_get_mtime_nsec(vfs_inode)); + + btrfs_set_timespec_sec(leaf, &item->ctime, inode_get_ctime_sec(vfs_inode)); + btrfs_set_timespec_nsec(leaf, &item->ctime, inode_get_ctime_nsec(vfs_inode)); + + btrfs_set_timespec_sec(leaf, &item->otime, inode->i_otime_sec); + btrfs_set_timespec_nsec(leaf, &item->otime, inode->i_otime_nsec); + + /* + * We do not need to set the nbytes field, in fact during a fast fsync + * its value may not even be correct, since a fast fsync does not wait + * for ordered extent completion, which is where we update nbytes, it + * only waits for writeback to complete. During log replay as we find + * file extent items and replay them, we adjust the nbytes field of the + * inode item in subvolume tree as needed (see overwrite_item()). + */ + + btrfs_set_inode_sequence(leaf, item, inode_peek_iversion(vfs_inode)); + btrfs_set_inode_transid(leaf, item, trans->transid); + btrfs_set_inode_rdev(leaf, item, vfs_inode->i_rdev); + flags = btrfs_inode_combine_flags(inode->flags, inode->ro_flags); + btrfs_set_inode_flags(leaf, item, flags); + btrfs_set_inode_block_group(leaf, item, 0); +} + +static int log_inode_item(struct btrfs_trans_handle *trans, + struct btrfs_root *log, struct btrfs_path *path, + struct btrfs_inode *inode, bool inode_item_dropped) +{ + struct btrfs_inode_item *inode_item; + struct btrfs_key key; + int ret; + + btrfs_get_inode_key(inode, &key); + /* + * If we are doing a fast fsync and the inode was logged before in the + * current transaction, then we know the inode was previously logged and + * it exists in the log tree. For performance reasons, in this case use + * btrfs_search_slot() directly with ins_len set to 0 so that we never + * attempt a write lock on the leaf's parent, which adds unnecessary lock + * contention in case there are concurrent fsyncs for other inodes of the + * same subvolume. Using btrfs_insert_empty_item() when the inode item + * already exists can also result in unnecessarily splitting a leaf. + */ + if (!inode_item_dropped && inode->logged_trans == trans->transid) { + ret = btrfs_search_slot(trans, log, &key, path, 0, 1); + ASSERT(ret <= 0); + if (ret > 0) + ret = -ENOENT; + } else { + /* + * This means it is the first fsync in the current transaction, + * so the inode item is not in the log and we need to insert it. + * We can never get -EEXIST because we are only called for a fast + * fsync and in case an inode eviction happens after the inode was + * logged before in the current transaction, when we load again + * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime + * flags and set ->logged_trans to 0. + */ + ret = btrfs_insert_empty_item(trans, log, path, &key, + sizeof(*inode_item)); + ASSERT(ret != -EEXIST); + } + if (ret) + return ret; + inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + fill_inode_item(trans, path->nodes[0], inode_item, inode, false, 0); + btrfs_release_path(path); + return 0; +} + +static int log_csums(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_root *log_root, + struct btrfs_ordered_sum *sums) +{ + const u64 lock_end = sums->logical + sums->len - 1; + struct extent_state *cached_state = NULL; + int ret; + + /* + * If this inode was not used for reflink operations in the current + * transaction with new extents, then do the fast path, no need to + * worry about logging checksum items with overlapping ranges. + */ + if (inode->last_reflink_trans < trans->transid) + return btrfs_insert_data_csums(trans, log_root, sums); + + /* + * Serialize logging for checksums. This is to avoid racing with the + * same checksum being logged by another task that is logging another + * file which happens to refer to the same extent as well. Such races + * can leave checksum items in the log with overlapping ranges. + */ + ret = btrfs_lock_extent(&log_root->log_csum_range, sums->logical, lock_end, + &cached_state); + if (ret) + return ret; + /* + * Due to extent cloning, we might have logged a csum item that covers a + * subrange of a cloned extent, and later we can end up logging a csum + * item for a larger subrange of the same extent or the entire range. + * This would leave csum items in the log tree that cover the same range + * and break the searches for checksums in the log tree, resulting in + * some checksums missing in the fs/subvolume tree. So just delete (or + * trim and adjust) any existing csum items in the log for this range. + */ + ret = btrfs_del_csums(trans, log_root, sums->logical, sums->len); + if (!ret) + ret = btrfs_insert_data_csums(trans, log_root, sums); + + btrfs_unlock_extent(&log_root->log_csum_range, sums->logical, lock_end, + &cached_state); + + return ret; +} + +static noinline int copy_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *dst_path, + struct btrfs_path *src_path, + int start_slot, int nr, enum btrfs_log_mode log_mode, + u64 logged_isize, struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *log = inode->root->log_root; + struct btrfs_file_extent_item *extent; + struct extent_buffer *src; + int ret; + struct btrfs_key *ins_keys; + u32 *ins_sizes; + struct btrfs_item_batch batch; + char AUTO_KFREE(ins_data); + int dst_index; + const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM); + const u64 i_size = i_size_read(&inode->vfs_inode); + + /* + * To keep lockdep happy and avoid deadlocks, clone the source leaf and + * use the clone. This is because otherwise we would be changing the log + * tree, to insert items from the subvolume tree or insert csum items, + * while holding a read lock on a leaf from the subvolume tree, which + * creates a nasty lock dependency when COWing log tree nodes/leaves: + * + * 1) Modifying the log tree triggers an extent buffer allocation while + * holding a write lock on a parent extent buffer from the log tree. + * Allocating the pages for an extent buffer, or the extent buffer + * struct, can trigger inode eviction and finally the inode eviction + * will trigger a release/remove of a delayed node, which requires + * taking the delayed node's mutex; + * + * 2) Allocating a metadata extent for a log tree can trigger the async + * reclaim thread and make us wait for it to release enough space and + * unblock our reservation ticket. The reclaim thread can start + * flushing delayed items, and that in turn results in the need to + * lock delayed node mutexes and in the need to write lock extent + * buffers of a subvolume tree - all this while holding a write lock + * on the parent extent buffer in the log tree. + * + * So one task in scenario 1) running in parallel with another task in + * scenario 2) could lead to a deadlock, one wanting to lock a delayed + * node mutex while having a read lock on a leaf from the subvolume, + * while the other is holding the delayed node's mutex and wants to + * write lock the same subvolume leaf for flushing delayed items. + */ + ret = clone_leaf(src_path, ctx); + if (ret < 0) + return ret; + + src = src_path->nodes[0]; + + ins_data = kmalloc_array(nr, sizeof(struct btrfs_key) + sizeof(u32), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + + ins_sizes = (u32 *)ins_data; + ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32)); + batch.keys = ins_keys; + batch.data_sizes = ins_sizes; + batch.total_data_size = 0; + batch.nr = 0; + + dst_index = 0; + for (int i = 0; i < nr; i++) { + const int src_slot = start_slot + i; + struct btrfs_root *csum_root; + struct btrfs_ordered_sum *sums; + struct btrfs_ordered_sum *sums_next; + LIST_HEAD(ordered_sums); + u64 disk_bytenr; + u64 disk_num_bytes; + u64 extent_offset; + u64 extent_num_bytes; + bool is_old_extent; + + btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot); + + if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY) + goto add_to_batch; + + extent = btrfs_item_ptr(src, src_slot, + struct btrfs_file_extent_item); + + is_old_extent = (btrfs_file_extent_generation(src, extent) < + trans->transid); + + /* + * Don't copy extents from past generations. That would make us + * log a lot more metadata for common cases like doing only a + * few random writes into a file and then fsync it for the first + * time or after the full sync flag is set on the inode. We can + * get leaves full of extent items, most of which are from past + * generations, so we can skip them - as long as the inode has + * not been the target of a reflink operation in this transaction, + * as in that case it might have had file extent items with old + * generations copied into it. We also must always log prealloc + * extents that start at or beyond eof, otherwise we would lose + * them on log replay. + */ + if (is_old_extent && + ins_keys[dst_index].offset < i_size && + inode->last_reflink_trans < trans->transid) + continue; + + if (skip_csum) + goto add_to_batch; + + /* Only regular extents have checksums. */ + if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG) + goto add_to_batch; + + /* + * If it's an extent created in a past transaction, then its + * checksums are already accessible from the committed csum tree, + * no need to log them. + */ + if (is_old_extent) + goto add_to_batch; + + disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent); + /* If it's an explicit hole, there are no checksums. */ + if (disk_bytenr == 0) + goto add_to_batch; + + disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent); + + if (btrfs_file_extent_compression(src, extent)) { + extent_offset = 0; + extent_num_bytes = disk_num_bytes; + } else { + extent_offset = btrfs_file_extent_offset(src, extent); + extent_num_bytes = btrfs_file_extent_num_bytes(src, extent); + } + + csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr); + if (unlikely(!csum_root)) { + btrfs_err(trans->fs_info, + "missing csum root for extent at bytenr %llu", + disk_bytenr); + return -EUCLEAN; + } + + disk_bytenr += extent_offset; + ret = btrfs_lookup_csums_list(csum_root, disk_bytenr, + disk_bytenr + extent_num_bytes - 1, + &ordered_sums, false); + if (ret < 0) + return ret; + ret = 0; + + list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) { + if (!ret) + ret = log_csums(trans, inode, log, sums); + list_del(&sums->list); + kfree(sums); + } + if (ret) + return ret; + +add_to_batch: + ins_sizes[dst_index] = btrfs_item_size(src, src_slot); + batch.total_data_size += ins_sizes[dst_index]; + batch.nr++; + dst_index++; + } + + /* + * We have a leaf full of old extent items that don't need to be logged, + * so we don't need to do anything. + */ + if (batch.nr == 0) + return 0; + + ret = btrfs_insert_empty_items(trans, log, dst_path, &batch); + if (ret) + return ret; + + dst_index = 0; + for (int i = 0; i < nr; i++) { + const int src_slot = start_slot + i; + const int dst_slot = dst_path->slots[0] + dst_index; + struct btrfs_key key; + unsigned long src_offset; + unsigned long dst_offset; + + /* + * We're done, all the remaining items in the source leaf + * correspond to old file extent items. + */ + if (dst_index >= batch.nr) + break; + + btrfs_item_key_to_cpu(src, &key, src_slot); + + if (key.type != BTRFS_EXTENT_DATA_KEY) + goto copy_item; + + extent = btrfs_item_ptr(src, src_slot, + struct btrfs_file_extent_item); + + /* See the comment in the previous loop, same logic. */ + if (btrfs_file_extent_generation(src, extent) < trans->transid && + key.offset < i_size && + inode->last_reflink_trans < trans->transid) + continue; + +copy_item: + dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot); + src_offset = btrfs_item_ptr_offset(src, src_slot); + + if (key.type == BTRFS_INODE_ITEM_KEY) { + struct btrfs_inode_item *inode_item; + + inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot, + struct btrfs_inode_item); + fill_inode_item(trans, dst_path->nodes[0], inode_item, + inode, log_mode == LOG_INODE_EXISTS, + logged_isize); + } else { + copy_extent_buffer(dst_path->nodes[0], src, dst_offset, + src_offset, ins_sizes[dst_index]); + } + + dst_index++; + } + + btrfs_release_path(dst_path); + + return ret; +} + +static int extent_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + const struct extent_map *em1, *em2; + + em1 = list_entry(a, struct extent_map, list); + em2 = list_entry(b, struct extent_map, list); + + if (em1->start < em2->start) + return -1; + else if (em1->start > em2->start) + return 1; + return 0; +} + +static int log_extent_csums(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_root *log_root, + const struct extent_map *em, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_root *csum_root; + u64 block_start; + u64 csum_offset; + u64 csum_len; + u64 mod_start = em->start; + u64 mod_len = em->len; + LIST_HEAD(ordered_sums); + int ret = 0; + + if (inode->flags & BTRFS_INODE_NODATASUM || + (em->flags & EXTENT_FLAG_PREALLOC) || + em->disk_bytenr == EXTENT_MAP_HOLE) + return 0; + + list_for_each_entry(ordered, &ctx->ordered_extents, log_list) { + const u64 ordered_end = ordered->file_offset + ordered->num_bytes; + const u64 mod_end = mod_start + mod_len; + struct btrfs_ordered_sum *sums; + + if (mod_len == 0) + break; + + if (ordered_end <= mod_start) + continue; + if (mod_end <= ordered->file_offset) + break; + + /* + * We are going to copy all the csums on this ordered extent, so + * go ahead and adjust mod_start and mod_len in case this ordered + * extent has already been logged. + */ + if (ordered->file_offset > mod_start) { + if (ordered_end >= mod_end) + mod_len = ordered->file_offset - mod_start; + /* + * If we have this case + * + * |--------- logged extent ---------| + * |----- ordered extent ----| + * + * Just don't mess with mod_start and mod_len, we'll + * just end up logging more csums than we need and it + * will be ok. + */ + } else { + if (ordered_end < mod_end) { + mod_len = mod_end - ordered_end; + mod_start = ordered_end; + } else { + mod_len = 0; + } + } + + /* + * To keep us from looping for the above case of an ordered + * extent that falls inside of the logged extent. + */ + if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags)) + continue; + + list_for_each_entry(sums, &ordered->csum_list, list) { + ret = log_csums(trans, inode, log_root, sums); + if (ret) + return ret; + } + } + + /* We're done, found all csums in the ordered extents. */ + if (mod_len == 0) + return 0; + + /* If we're compressed we have to save the entire range of csums. */ + if (btrfs_extent_map_is_compressed(em)) { + csum_offset = 0; + csum_len = em->disk_num_bytes; + } else { + csum_offset = mod_start - em->start; + csum_len = mod_len; + } + + /* block start is already adjusted for the file extent offset. */ + block_start = btrfs_extent_map_block_start(em); + csum_root = btrfs_csum_root(trans->fs_info, block_start); + if (unlikely(!csum_root)) { + btrfs_err(trans->fs_info, + "missing csum root for extent at bytenr %llu", + block_start); + return -EUCLEAN; + } + + ret = btrfs_lookup_csums_list(csum_root, block_start + csum_offset, + block_start + csum_offset + csum_len - 1, + &ordered_sums, false); + if (ret < 0) + return ret; + ret = 0; + + while (!list_empty(&ordered_sums)) { + struct btrfs_ordered_sum *sums = list_first_entry(&ordered_sums, + struct btrfs_ordered_sum, + list); + if (!ret) + ret = log_csums(trans, inode, log_root, sums); + list_del(&sums->list); + kfree(sums); + } + + return ret; +} + +static int log_one_extent(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + const struct extent_map *em, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_drop_extents_args drop_args = { 0 }; + struct btrfs_root *log = inode->root->log_root; + struct btrfs_file_extent_item fi = { 0 }; + struct extent_buffer *leaf; + struct btrfs_key key; + enum btrfs_compression_type compress_type; + u64 extent_offset = em->offset; + u64 block_start = btrfs_extent_map_block_start(em); + u64 block_len; + int ret; + + btrfs_set_stack_file_extent_generation(&fi, trans->transid); + if (em->flags & EXTENT_FLAG_PREALLOC) + btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC); + else + btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG); + + block_len = em->disk_num_bytes; + compress_type = btrfs_extent_map_compression(em); + if (compress_type != BTRFS_COMPRESS_NONE) { + btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start); + btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len); + } else if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE) { + btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start - extent_offset); + btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len); + } + + btrfs_set_stack_file_extent_offset(&fi, extent_offset); + btrfs_set_stack_file_extent_num_bytes(&fi, em->len); + btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes); + btrfs_set_stack_file_extent_compression(&fi, compress_type); + + ret = log_extent_csums(trans, inode, log, em, ctx); + if (ret) + return ret; + + /* + * If this is the first time we are logging the inode in the current + * transaction, we can avoid btrfs_drop_extents(), which is expensive + * because it does a deletion search, which always acquires write locks + * for extent buffers at levels 2, 1 and 0. This not only wastes time + * but also adds significant contention in a log tree, since log trees + * are small, with a root at level 2 or 3 at most, due to their short + * life span. + */ + if (ctx->logged_before) { + drop_args.path = path; + drop_args.start = em->start; + drop_args.end = btrfs_extent_map_end(em); + drop_args.replace_extent = true; + drop_args.extent_item_size = sizeof(fi); + ret = btrfs_drop_extents(trans, log, inode, &drop_args); + if (ret) + return ret; + } + + if (!drop_args.extent_inserted) { + key.objectid = btrfs_ino(inode); + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = em->start; + + ret = btrfs_insert_empty_item(trans, log, path, &key, + sizeof(fi)); + if (ret) + return ret; + } + leaf = path->nodes[0]; + write_extent_buffer(leaf, &fi, + btrfs_item_ptr_offset(leaf, path->slots[0]), + sizeof(fi)); + + btrfs_release_path(path); + + return ret; +} + +/* + * Log all prealloc extents beyond the inode's i_size to make sure we do not + * lose them after doing a full/fast fsync and replaying the log. We scan the + * subvolume's root instead of iterating the inode's extent map tree because + * otherwise we can log incorrect extent items based on extent map conversion. + * That can happen due to the fact that extent maps are merged when they + * are not in the extent map tree's list of modified extents. + */ +static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key; + const u64 i_size = i_size_read(&inode->vfs_inode); + const u64 ino = btrfs_ino(inode); + BTRFS_PATH_AUTO_FREE(dst_path); + bool dropped_extents = false; + u64 truncate_offset = i_size; + struct extent_buffer *leaf; + int slot; + int ins_nr = 0; + int start_slot = 0; + int ret; + + if (!(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = i_size; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + /* + * We must check if there is a prealloc extent that starts before the + * i_size and crosses the i_size boundary. This is to ensure later we + * truncate down to the end of that extent and not to the i_size, as + * otherwise we end up losing part of the prealloc extent after a log + * replay and with an implicit hole if there is another prealloc extent + * that starts at an offset beyond i_size. + */ + ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY); + if (ret < 0) + goto out; + + if (ret == 0) { + struct btrfs_file_extent_item *ei; + + leaf = path->nodes[0]; + slot = path->slots[0]; + ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + + if (btrfs_file_extent_type(leaf, ei) == + BTRFS_FILE_EXTENT_PREALLOC) { + u64 extent_end; + + btrfs_item_key_to_cpu(leaf, &key, slot); + extent_end = key.offset + + btrfs_file_extent_num_bytes(leaf, ei); + + if (extent_end > i_size) + truncate_offset = extent_end; + } + } else { + ret = 0; + } + + while (true) { + leaf = path->nodes[0]; + slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(leaf)) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0, ctx); + if (ret < 0) + goto out; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid > ino) + break; + if (WARN_ON_ONCE(key.objectid < ino) || + key.type < BTRFS_EXTENT_DATA_KEY || + key.offset < i_size) { + path->slots[0]++; + continue; + } + /* + * Avoid overlapping items in the log tree. The first time we + * get here, get rid of everything from a past fsync. After + * that, if the current extent starts before the end of the last + * extent we copied, truncate the last one. This can happen if + * an ordered extent completion modifies the subvolume tree + * while btrfs_next_leaf() has the tree unlocked. + */ + if (!dropped_extents || key.offset < truncate_offset) { + ret = truncate_inode_items(trans, root->log_root, inode, + min(key.offset, truncate_offset), + BTRFS_EXTENT_DATA_KEY); + if (ret) + goto out; + dropped_extents = true; + } + truncate_offset = btrfs_file_extent_end(path); + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + if (!dst_path) { + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + } + } + if (ins_nr > 0) + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0, ctx); +out: + btrfs_release_path(path); + return ret; +} + +static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_ordered_extent *tmp; + struct extent_map *em, *n; + LIST_HEAD(extents); + struct extent_map_tree *tree = &inode->extent_tree; + int ret = 0; + int num = 0; + + write_lock(&tree->lock); + + list_for_each_entry_safe(em, n, &tree->modified_extents, list) { + list_del_init(&em->list); + /* + * Just an arbitrary number, this can be really CPU intensive + * once we start getting a lot of extents, and really once we + * have a bunch of extents we just want to commit since it will + * be faster. + */ + if (++num > 32768) { + list_del_init(&tree->modified_extents); + ret = -EFBIG; + goto process; + } + + if (em->generation < trans->transid) + continue; + + /* We log prealloc extents beyond eof later. */ + if ((em->flags & EXTENT_FLAG_PREALLOC) && + em->start >= i_size_read(&inode->vfs_inode)) + continue; + + /* Need a ref to keep it from getting evicted from cache */ + refcount_inc(&em->refs); + em->flags |= EXTENT_FLAG_LOGGING; + list_add_tail(&em->list, &extents); + num++; + } + + list_sort(NULL, &extents, extent_cmp); +process: + while (!list_empty(&extents)) { + em = list_first_entry(&extents, struct extent_map, list); + + list_del_init(&em->list); + + /* + * If we had an error we just need to delete everybody from our + * private list. + */ + if (ret) { + btrfs_clear_em_logging(inode, em); + btrfs_free_extent_map(em); + continue; + } + + write_unlock(&tree->lock); + + ret = log_one_extent(trans, inode, em, path, ctx); + write_lock(&tree->lock); + btrfs_clear_em_logging(inode, em); + btrfs_free_extent_map(em); + } + WARN_ON(!list_empty(&extents)); + write_unlock(&tree->lock); + + if (!ret) + ret = btrfs_log_prealloc_extents(trans, inode, path, ctx); + if (ret) + return ret; + + /* + * We have logged all extents successfully, now make sure the commit of + * the current transaction waits for the ordered extents to complete + * before it commits and wipes out the log trees, otherwise we would + * lose data if an ordered extents completes after the transaction + * commits and a power failure happens after the transaction commit. + */ + list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) { + list_del_init(&ordered->log_list); + set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags); + + if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { + spin_lock(&inode->ordered_tree_lock); + if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) { + set_bit(BTRFS_ORDERED_PENDING, &ordered->flags); + atomic_inc(&trans->transaction->pending_ordered); + } + spin_unlock(&inode->ordered_tree_lock); + } + btrfs_put_ordered_extent(ordered); + } + + return 0; +} + +static int get_inode_size_to_log(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, u64 *size_ret) +{ + struct btrfs_key key; + struct btrfs_inode_item *item; + int ret; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + /* + * Our caller called inode_logged(), so logged_trans is up to date. + * Use data_race() to silence any warning from KCSAN. Once logged_trans + * is set, it can only be reset to 0 after inode eviction. + */ + if (data_race(inode->logged_trans) == trans->transid) { + ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0); + } else if (inode->generation < trans->transid) { + path->search_commit_root = true; + path->skip_locking = true; + ret = btrfs_search_slot(NULL, inode->root, &key, path, 0, 0); + path->search_commit_root = false; + path->skip_locking = false; + + } else { + *size_ret = 0; + return 0; + } + + /* + * If the inode was logged before or is from a past transaction, then + * its inode item must exist in the log root or in the commit root. + */ + ASSERT(ret <= 0); + if (WARN_ON_ONCE(ret > 0)) + ret = -ENOENT; + + if (ret < 0) + return ret; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + *size_ret = btrfs_inode_size(path->nodes[0], item); + /* + * If the in-memory inode's i_size is smaller then the inode size stored + * in the btree, return the inode's i_size, so that we get a correct + * inode size after replaying the log when before a power failure we had + * a shrinking truncate followed by addition of a new name (rename / new + * hard link). Otherwise return the inode size from the btree, to avoid + * data loss when replaying a log due to previously doing a write that + * expands the inode's size and logging a new name immediately after. + */ + if (*size_ret > inode->vfs_inode.i_size) + *size_ret = inode->vfs_inode.i_size; + + btrfs_release_path(path); + return 0; +} + +/* + * At the moment we always log all xattrs. This is to figure out at log replay + * time which xattrs must have their deletion replayed. If a xattr is missing + * in the log tree and exists in the fs/subvol tree, we delete it. This is + * because if a xattr is deleted, the inode is fsynced and a power failure + * happens, causing the log to be replayed the next time the fs is mounted, + * we want the xattr to not exist anymore (same behaviour as other filesystems + * with a journal, ext3/4, xfs, f2fs, etc). + */ +static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + struct btrfs_path *dst_path, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + int ret; + struct btrfs_key key; + const u64 ino = btrfs_ino(inode); + int ins_nr = 0; + int start_slot = 0; + bool found_xattrs = false; + + if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags)) + return 0; + + key.objectid = ino; + key.type = BTRFS_XATTR_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + while (true) { + int slot = path->slots[0]; + struct extent_buffer *leaf = path->nodes[0]; + int nritems = btrfs_header_nritems(leaf); + + if (slot >= nritems) { + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0, ctx); + if (ret < 0) + return ret; + ins_nr = 0; + } + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) + break; + + if (ins_nr == 0) + start_slot = slot; + ins_nr++; + path->slots[0]++; + found_xattrs = true; + cond_resched(); + } + if (ins_nr > 0) { + ret = copy_items(trans, inode, dst_path, path, + start_slot, ins_nr, 1, 0, ctx); + if (ret < 0) + return ret; + } + + if (!found_xattrs) + set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags); + + return 0; +} + +/* + * When using the NO_HOLES feature if we punched a hole that causes the + * deletion of entire leafs or all the extent items of the first leaf (the one + * that contains the inode item and references) we may end up not processing + * any extents, because there are no leafs with a generation matching the + * current transaction that have extent items for our inode. So we need to find + * if any holes exist and then log them. We also need to log holes after any + * truncate operation that changes the inode's size. + */ +static int btrfs_log_holes(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_key key; + const u64 ino = btrfs_ino(inode); + const u64 i_size = i_size_read(&inode->vfs_inode); + u64 prev_extent_end = 0; + int ret; + + if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0) + return 0; + + /* + * If there are no prealloc extents (which can be located past i_size), + * and disk space used is greater than or equals to i_size, then there + * are no holes. + */ + if (!(inode->flags & BTRFS_INODE_PREALLOC) && + i_size <= inode_get_bytes(&inode->vfs_inode)) + return 0; + + key.objectid = ino; + key.type = BTRFS_EXTENT_DATA_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + if (ret > 0) { + ret = 0; + break; + } + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) + break; + + /* We have a hole, log it. */ + if (prev_extent_end < key.offset) { + const u64 hole_len = key.offset - prev_extent_end; + + /* + * Release the path to avoid deadlocks with other code + * paths that search the root while holding locks on + * leafs from the log root. + */ + btrfs_release_path(path); + ret = btrfs_insert_hole_extent(trans, root->log_root, + ino, prev_extent_end, + hole_len); + if (ret < 0) + return ret; + + /* + * Search for the same key again in the root. Since it's + * an extent item and we are holding the inode lock, the + * key must still exist. If it doesn't just emit warning + * and return an error to fall back to a transaction + * commit. + */ + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + if (WARN_ON(ret > 0)) + return -ENOENT; + leaf = path->nodes[0]; + } + + prev_extent_end = btrfs_file_extent_end(path); + path->slots[0]++; + cond_resched(); + } + + if (prev_extent_end < i_size) { + u64 hole_len; + + btrfs_release_path(path); + hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize); + ret = btrfs_insert_hole_extent(trans, root->log_root, ino, + prev_extent_end, hole_len); + if (ret < 0) + return ret; + } + + return 0; +} + +/* + * When we are logging a new inode X, check if it doesn't have a reference that + * matches the reference from some other inode Y created in a past transaction + * and that was renamed in the current transaction. If we don't do this, then at + * log replay time we can lose inode Y (and all its files if it's a directory): + * + * mkdir /mnt/x + * echo "hello world" > /mnt/x/foobar + * sync + * mv /mnt/x /mnt/y + * mkdir /mnt/x # or touch /mnt/x + * xfs_io -c fsync /mnt/x + * <power fail> + * mount fs, trigger log replay + * + * After the log replay procedure, we would lose the first directory and all its + * files (file foobar). + * For the case where inode Y is not a directory we simply end up losing it: + * + * echo "123" > /mnt/foo + * sync + * mv /mnt/foo /mnt/bar + * echo "abc" > /mnt/foo + * xfs_io -c fsync /mnt/foo + * <power fail> + * + * We also need this for cases where a snapshot entry is replaced by some other + * entry (file or directory) otherwise we end up with an unreplayable log due to + * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as + * if it were a regular entry: + * + * mkdir /mnt/x + * btrfs subvolume snapshot /mnt /mnt/x/snap + * btrfs subvolume delete /mnt/x/snap + * rmdir /mnt/x + * mkdir /mnt/x + * fsync /mnt/x or fsync some new file inside it + * <power fail> + * + * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in + * the same transaction. + */ +static int btrfs_check_ref_name_override(struct extent_buffer *eb, + const int slot, + const struct btrfs_key *key, + struct btrfs_inode *inode, + u64 *other_ino, u64 *other_parent) +{ + BTRFS_PATH_AUTO_FREE(search_path); + char AUTO_KFREE(name); + u32 name_len = 0; + u32 item_size = btrfs_item_size(eb, slot); + u32 cur_offset = 0; + unsigned long ptr = btrfs_item_ptr_offset(eb, slot); + + search_path = btrfs_alloc_path(); + if (!search_path) + return -ENOMEM; + search_path->search_commit_root = true; + search_path->skip_locking = true; + + while (cur_offset < item_size) { + u64 parent; + u32 this_name_len; + u32 this_len; + unsigned long name_ptr; + struct btrfs_dir_item *di; + struct fscrypt_str name_str; + + if (key->type == BTRFS_INODE_REF_KEY) { + struct btrfs_inode_ref *iref; + + iref = (struct btrfs_inode_ref *)(ptr + cur_offset); + parent = key->offset; + this_name_len = btrfs_inode_ref_name_len(eb, iref); + name_ptr = (unsigned long)(iref + 1); + this_len = sizeof(*iref) + this_name_len; + } else { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)(ptr + + cur_offset); + parent = btrfs_inode_extref_parent(eb, extref); + this_name_len = btrfs_inode_extref_name_len(eb, extref); + name_ptr = (unsigned long)&extref->name; + this_len = sizeof(*extref) + this_name_len; + } + + if (this_name_len > name_len) { + char *new_name; + + new_name = krealloc(name, this_name_len, GFP_NOFS); + if (!new_name) + return -ENOMEM; + name_len = this_name_len; + name = new_name; + } + + read_extent_buffer(eb, name, name_ptr, this_name_len); + + name_str.name = name; + name_str.len = this_name_len; + di = btrfs_lookup_dir_item(NULL, inode->root, search_path, + parent, &name_str, 0); + if (!IS_ERR_OR_NULL(di)) { + struct btrfs_key di_key; + + btrfs_dir_item_key_to_cpu(search_path->nodes[0], + di, &di_key); + if (di_key.type == BTRFS_INODE_ITEM_KEY) { + if (di_key.objectid != key->objectid) { + *other_ino = di_key.objectid; + *other_parent = parent; + return 1; + } else { + return 0; + } + } else { + return -EAGAIN; + } + } else if (IS_ERR(di)) { + return PTR_ERR(di); + } + btrfs_release_path(search_path); + + cur_offset += this_len; + } + + return 0; +} + +/* + * Check if we need to log an inode. This is used in contexts where while + * logging an inode we need to log another inode (either that it exists or in + * full mode). This is used instead of btrfs_inode_in_log() because the later + * requires the inode to be in the log and have the log transaction committed, + * while here we do not care if the log transaction was already committed - our + * caller will commit the log later - and we want to avoid logging an inode + * multiple times when multiple tasks have joined the same log transaction. + */ +static bool need_log_inode(const struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + /* + * If a directory was not modified, no dentries added or removed, we can + * and should avoid logging it. + */ + if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid) + return false; + + /* + * If this inode does not have new/updated/deleted xattrs since the last + * time it was logged and is flagged as logged in the current transaction, + * we can skip logging it. As for new/deleted names, those are updated in + * the log by link/unlink/rename operations. + * In case the inode was logged and then evicted and reloaded, its + * logged_trans will be 0, in which case we have to fully log it since + * logged_trans is a transient field, not persisted. + */ + if (inode_logged(trans, inode, NULL) == 1 && + !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags)) + return false; + + return true; +} + +struct btrfs_dir_list { + u64 ino; + struct list_head list; +}; + +/* + * Log the inodes of the new dentries of a directory. + * See process_dir_items_leaf() for details about why it is needed. + * This is a recursive operation - if an existing dentry corresponds to a + * directory, that directory's new entries are logged too (same behaviour as + * ext3/4, xfs, f2fs, nilfs2). Note that when logging the inodes + * the dentries point to we do not acquire their VFS lock, otherwise lockdep + * complains about the following circular lock dependency / possible deadlock: + * + * CPU0 CPU1 + * ---- ---- + * lock(&type->i_mutex_dir_key#3/2); + * lock(sb_internal#2); + * lock(&type->i_mutex_dir_key#3/2); + * lock(&sb->s_type->i_mutex_key#14); + * + * Where sb_internal is the lock (a counter that works as a lock) acquired by + * sb_start_intwrite() in btrfs_start_transaction(). + * Not acquiring the VFS lock of the inodes is still safe because: + * + * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible + * that while logging the inode new references (names) are added or removed + * from the inode, leaving the logged inode item with a link count that does + * not match the number of logged inode reference items. This is fine because + * at log replay time we compute the real number of links and correct the + * link count in the inode item (see replay_one_buffer() and + * link_to_fixup_dir()); + * + * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that + * while logging the inode's items new index items (key type + * BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item + * has a size that doesn't match the sum of the lengths of all the logged + * names - this is ok, not a problem, because at log replay time we set the + * directory's i_size to the correct value (see replay_one_name() and + * overwrite_item()). + */ +static int log_new_dir_dentries(struct btrfs_trans_handle *trans, + struct btrfs_inode *start_inode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = start_inode->root; + struct btrfs_path *path; + LIST_HEAD(dir_list); + struct btrfs_dir_list *dir_elem; + u64 ino = btrfs_ino(start_inode); + struct btrfs_inode *curr_inode = start_inode; + int ret = 0; + + trace_btrfs_log_new_dir_dentries_enter(trans, start_inode); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + /* Pairs with btrfs_add_delayed_iput below. */ + ihold(&curr_inode->vfs_inode); + + while (true) { + struct btrfs_key key; + struct btrfs_key found_key; + u64 next_index; + bool continue_curr_inode = true; + int iter_ret; + + key.objectid = ino; + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = btrfs_get_first_dir_index_to_log(curr_inode); + next_index = key.offset; +again: + btrfs_for_each_slot(root->log_root, &key, &found_key, path, iter_ret) { + struct extent_buffer *leaf = path->nodes[0]; + struct btrfs_dir_item *di; + struct btrfs_key di_key; + struct btrfs_inode *di_inode; + int log_mode = LOG_INODE_EXISTS; + int type; + + if (found_key.objectid != ino || + found_key.type != BTRFS_DIR_INDEX_KEY) { + continue_curr_inode = false; + break; + } + + next_index = found_key.offset + 1; + + di = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item); + type = btrfs_dir_ftype(leaf, di); + if (btrfs_dir_transid(leaf, di) < trans->transid) + continue; + btrfs_dir_item_key_to_cpu(leaf, di, &di_key); + if (di_key.type == BTRFS_ROOT_ITEM_KEY) + continue; + + btrfs_release_path(path); + di_inode = btrfs_iget_logging(di_key.objectid, root); + if (IS_ERR(di_inode)) { + ret = PTR_ERR(di_inode); + goto out; + } + + if (!need_log_inode(trans, di_inode)) { + btrfs_add_delayed_iput(di_inode); + break; + } + + ctx->log_new_dentries = false; + if (type == BTRFS_FT_DIR) + log_mode = LOG_INODE_ALL; + ret = btrfs_log_inode(trans, di_inode, log_mode, ctx); + btrfs_add_delayed_iput(di_inode); + if (ret) + goto out; + if (ctx->log_new_dentries) { + dir_elem = kmalloc_obj(*dir_elem, GFP_NOFS); + if (!dir_elem) { + ret = -ENOMEM; + goto out; + } + dir_elem->ino = di_key.objectid; + list_add_tail(&dir_elem->list, &dir_list); + } + break; + } + + btrfs_release_path(path); + + if (iter_ret < 0) { + ret = iter_ret; + goto out; + } else if (iter_ret > 0) { + continue_curr_inode = false; + } else { + key = found_key; + } + + if (continue_curr_inode && key.offset < (u64)-1) { + key.offset++; + goto again; + } + + btrfs_set_first_dir_index_to_log(curr_inode, next_index); + + if (list_empty(&dir_list)) + break; + + dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list); + ino = dir_elem->ino; + list_del(&dir_elem->list); + kfree(dir_elem); + + btrfs_add_delayed_iput(curr_inode); + + curr_inode = btrfs_iget_logging(ino, root); + if (IS_ERR(curr_inode)) { + ret = PTR_ERR(curr_inode); + curr_inode = NULL; + break; + } + } +out: + btrfs_free_path(path); + if (curr_inode) + btrfs_add_delayed_iput(curr_inode); + + if (ret) { + struct btrfs_dir_list *next; + + list_for_each_entry_safe(dir_elem, next, &dir_list, list) + kfree(dir_elem); + } + + trace_btrfs_log_new_dir_dentries_exit(trans, start_inode, ret); + + return ret; +} + +struct btrfs_ino_list { + u64 ino; + u64 parent; + struct list_head list; +}; + +static void free_conflicting_inodes(struct btrfs_log_ctx *ctx) +{ + struct btrfs_ino_list *curr; + struct btrfs_ino_list *next; + + list_for_each_entry_safe(curr, next, &ctx->conflict_inodes, list) { + list_del(&curr->list); + kfree(curr); + } +} + +static int conflicting_inode_is_dir(struct btrfs_root *root, u64 ino, + struct btrfs_path *path) +{ + struct btrfs_key key; + int ret; + + key.objectid = ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + path->search_commit_root = true; + path->skip_locking = true; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (WARN_ON_ONCE(ret > 0)) { + /* + * We have previously found the inode through the commit root + * so this should not happen. If it does, just error out and + * fallback to a transaction commit. + */ + ret = -ENOENT; + } else if (ret == 0) { + struct btrfs_inode_item *item; + + item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + if (S_ISDIR(btrfs_inode_mode(path->nodes[0], item))) + ret = 1; + } + + btrfs_release_path(path); + path->search_commit_root = false; + path->skip_locking = false; + + return ret; +} + +static bool can_log_conflicting_inode(const struct btrfs_trans_handle *trans, + const struct btrfs_inode *inode) +{ + if (!S_ISDIR(inode->vfs_inode.i_mode)) + return true; + + if (inode->last_unlink_trans < trans->transid) + return true; + + /* + * If this is a directory and its unlink_trans is not from a past + * transaction then we must fallback to a transaction commit in order + * to avoid getting a directory with 2 hard links after log replay. + * + * This happens if a directory A is renamed, moved from one parent + * directory to another one, a new file is created in the old parent + * directory with the old name of our directory A, the new file is + * fsynced, then we moved the new file to some other parent directory + * and fsync again the new file. This results in a log tree where we + * logged that directory A existed, with the INODE_REF item for the + * new location but without having logged its old parent inode, so + * that on log replay we add a new link for the new location but the + * old link remains, resulting in a link count of 2. + */ + return false; +} + +static int add_conflicting_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + u64 ino, u64 parent, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_ino_list *ino_elem; + struct btrfs_inode *inode; + int ret = 0; + + trace_btrfs_add_conflicting_inode_enter(trans, ctx, ino, parent); + + /* + * It's rare to have a lot of conflicting inodes, in practice it is not + * common to have more than 1 or 2. We don't want to collect too many, + * as we could end up logging too many inodes (even if only in + * LOG_INODE_EXISTS mode) and slow down other fsyncs or transaction + * commits. + */ + if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + inode = btrfs_iget_logging(ino, root); + /* + * If the other inode that had a conflicting dir entry was deleted in + * the current transaction then we either: + * + * 1) Log the parent directory (later after adding it to the list) if + * the inode is a directory. This is because it may be a deleted + * subvolume/snapshot or it may be a regular directory that had + * deleted subvolumes/snapshots (or subdirectories that had them), + * and at the moment we can't deal with dropping subvolumes/snapshots + * during log replay. So we just log the parent, which will result in + * a fallback to a transaction commit if we are dealing with those + * cases (last_unlink_trans will match the current transaction); + * + * 2) Do nothing if it's not a directory. During log replay we simply + * unlink the conflicting dentry from the parent directory and then + * add the dentry for our inode. Like this we can avoid logging the + * parent directory (and maybe fallback to a transaction commit in + * case it has a last_unlink_trans == trans->transid, due to moving + * some inode from it to some other directory). + */ + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + if (ret != -ENOENT) + goto out; + + ret = conflicting_inode_is_dir(root, ino, path); + /* Not a directory or we got an error. */ + if (ret <= 0) + goto out; + + /* Conflicting inode is a directory, so we'll log its parent. */ + ino_elem = kmalloc_obj(*ino_elem, GFP_NOFS); + if (!ino_elem) { + ret = -ENOMEM; + goto out; + } + ino_elem->ino = ino; + ino_elem->parent = parent; + list_add_tail(&ino_elem->list, &ctx->conflict_inodes); + ctx->num_conflict_inodes++; + ret = 0; + goto out; + } + + /* + * If the inode was already logged skip it - otherwise we can hit an + * infinite loop. Example: + * + * From the commit root (previous transaction) we have the following + * inodes: + * + * inode 257 a directory + * inode 258 with references "zz" and "zz_link" on inode 257 + * inode 259 with reference "a" on inode 257 + * + * And in the current (uncommitted) transaction we have: + * + * inode 257 a directory, unchanged + * inode 258 with references "a" and "a2" on inode 257 + * inode 259 with reference "zz_link" on inode 257 + * inode 261 with reference "zz" on inode 257 + * + * When logging inode 261 the following infinite loop could + * happen if we don't skip already logged inodes: + * + * - we detect inode 258 as a conflicting inode, with inode 261 + * on reference "zz", and log it; + * + * - we detect inode 259 as a conflicting inode, with inode 258 + * on reference "a", and log it; + * + * - we detect inode 258 as a conflicting inode, with inode 259 + * on reference "zz_link", and log it - again! After this we + * repeat the above steps forever. + * + * Here we can use need_log_inode() because we only need to log the + * inode in LOG_INODE_EXISTS mode and rename operations update the log, + * so that the log ends up with the new name and without the old name. + */ + if (!need_log_inode(trans, inode)) { + btrfs_add_delayed_iput(inode); + goto out; + } + + if (!can_log_conflicting_inode(trans, inode)) { + btrfs_add_delayed_iput(inode); + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + btrfs_add_delayed_iput(inode); + + ino_elem = kmalloc_obj(*ino_elem, GFP_NOFS); + if (!ino_elem) { + ret = -ENOMEM; + goto out; + } + ino_elem->ino = ino; + ino_elem->parent = parent; + list_add_tail(&ino_elem->list, &ctx->conflict_inodes); + ctx->num_conflict_inodes++; + +out: + trace_btrfs_add_conflicting_inode_exit(trans, ctx, ino, parent, ret); + + return ret; +} + +static int log_conflicting_inodes(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_log_ctx *ctx) +{ + const bool orig_log_new_dentries = ctx->log_new_dentries; + int ret = 0; + + /* + * Conflicting inodes are logged by the first call to btrfs_log_inode(), + * otherwise we could have unbounded recursion of btrfs_log_inode() + * calls. This check guarantees we can have only 1 level of recursion. + */ + if (ctx->logging_conflict_inodes) + return 0; + + /* + * Avoid any work if no conflicting inodes and emitting the trace event + * which only adds noise and it's useless if there are no inodes. + */ + if (list_empty(&ctx->conflict_inodes)) + return 0; + + ctx->logging_conflict_inodes = true; + trace_btrfs_log_conflicting_inodes_enter(trans, ctx); + + /* + * New conflicting inodes may be found and added to the list while we + * are logging a conflicting inode, so keep iterating while the list is + * not empty. + */ + while (!list_empty(&ctx->conflict_inodes)) { + struct btrfs_ino_list *curr; + struct btrfs_inode *inode; + u64 ino; + u64 parent; + + curr = list_first_entry(&ctx->conflict_inodes, + struct btrfs_ino_list, list); + ino = curr->ino; + parent = curr->parent; + list_del(&curr->list); + kfree(curr); + + inode = btrfs_iget_logging(ino, root); + /* + * If the other inode that had a conflicting dir entry was + * deleted in the current transaction, we need to log its parent + * directory. See the comment at add_conflicting_inode(). + */ + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + if (ret != -ENOENT) + break; + + inode = btrfs_iget_logging(parent, root); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + break; + } + + if (!can_log_conflicting_inode(trans, inode)) { + btrfs_add_delayed_iput(inode); + ret = BTRFS_LOG_FORCE_COMMIT; + break; + } + + /* + * Always log the directory, we cannot make this + * conditional on need_log_inode() because the directory + * might have been logged in LOG_INODE_EXISTS mode or + * the dir index of the conflicting inode is not in a + * dir index key range logged for the directory. So we + * must make sure the deletion is recorded. + */ + ctx->log_new_dentries = false; + ret = btrfs_log_inode(trans, inode, LOG_INODE_ALL, ctx); + if (!ret && ctx->log_new_dentries) + ret = log_new_dir_dentries(trans, inode, ctx); + + btrfs_add_delayed_iput(inode); + if (ret) + break; + continue; + } + + /* + * Here we can use need_log_inode() because we only need to log + * the inode in LOG_INODE_EXISTS mode and rename operations + * update the log, so that the log ends up with the new name and + * without the old name. + * + * We did this check at add_conflicting_inode(), but here we do + * it again because if some other task logged the inode after + * that, we can avoid doing it again. + */ + if (!need_log_inode(trans, inode)) { + btrfs_add_delayed_iput(inode); + continue; + } + + /* + * We are safe logging the other inode without acquiring its + * lock as long as we log with the LOG_INODE_EXISTS mode. We + * are safe against concurrent renames of the other inode as + * well because during a rename we pin the log and update the + * log with the new name before we unpin it. + */ + ret = btrfs_log_inode(trans, inode, LOG_INODE_EXISTS, ctx); + btrfs_add_delayed_iput(inode); + if (ret) + break; + } + + ctx->log_new_dentries = orig_log_new_dentries; + ctx->logging_conflict_inodes = false; + if (ret) + free_conflicting_inodes(ctx); + trace_btrfs_log_conflicting_inodes_exit(trans, ctx, ret); + + return ret; +} + +static int copy_inode_items_to_log(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_key *min_key, + const struct btrfs_key *max_key, + struct btrfs_path *path, + struct btrfs_path *dst_path, + const u64 logged_isize, + const enum btrfs_log_mode log_mode, + struct btrfs_log_ctx *ctx, + bool *need_log_inode_item) +{ + const u64 i_size = i_size_read(&inode->vfs_inode); + struct btrfs_root *root = inode->root; + int ins_start_slot = 0; + int ins_nr = 0; + int ret; + + while (1) { + ret = btrfs_search_forward(root, min_key, path, trans->transid); + if (ret < 0) + return ret; + if (ret > 0) { + ret = 0; + break; + } +again: + /* Note, ins_nr might be > 0 here, cleanup outside the loop */ + if (min_key->objectid != max_key->objectid) + break; + if (min_key->type > max_key->type) + break; + + if (min_key->type == BTRFS_INODE_ITEM_KEY) { + *need_log_inode_item = false; + } else if (min_key->type == BTRFS_EXTENT_DATA_KEY && + min_key->offset >= i_size) { + /* + * Extents at and beyond eof are logged with + * btrfs_log_prealloc_extents(). + * Only regular files have BTRFS_EXTENT_DATA_KEY keys, + * and no keys greater than that, so bail out. + */ + break; + } else if (min_key->type == BTRFS_INODE_REF_KEY || + min_key->type == BTRFS_INODE_EXTREF_KEY) { + u64 other_ino = 0; + u64 other_parent = 0; + + ret = btrfs_check_ref_name_override(path->nodes[0], + path->slots[0], min_key, inode, + &other_ino, &other_parent); + if (ret < 0) { + return ret; + } else if (ret > 0 && + other_ino != btrfs_ino(ctx->inode)) { + if (ins_nr > 0) { + ins_nr++; + } else { + ins_nr = 1; + ins_start_slot = path->slots[0]; + } + ret = copy_items(trans, inode, dst_path, path, + ins_start_slot, ins_nr, + log_mode, logged_isize, ctx); + if (ret < 0) + return ret; + ins_nr = 0; + + btrfs_release_path(path); + ret = add_conflicting_inode(trans, root, path, + other_ino, + other_parent, ctx); + if (ret) + return ret; + goto next_key; + } + } else if (min_key->type == BTRFS_XATTR_ITEM_KEY) { + /* Skip xattrs, logged later with btrfs_log_all_xattrs() */ + if (ins_nr == 0) + goto next_slot; + ret = copy_items(trans, inode, dst_path, path, + ins_start_slot, + ins_nr, log_mode, logged_isize, ctx); + if (ret < 0) + return ret; + ins_nr = 0; + goto next_slot; + } + + if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) { + ins_nr++; + goto next_slot; + } else if (!ins_nr) { + ins_start_slot = path->slots[0]; + ins_nr = 1; + goto next_slot; + } + + ret = copy_items(trans, inode, dst_path, path, ins_start_slot, + ins_nr, log_mode, logged_isize, ctx); + if (ret < 0) + return ret; + ins_nr = 1; + ins_start_slot = path->slots[0]; +next_slot: + path->slots[0]++; + if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { + btrfs_item_key_to_cpu(path->nodes[0], min_key, + path->slots[0]); + goto again; + } + if (ins_nr) { + ret = copy_items(trans, inode, dst_path, path, + ins_start_slot, ins_nr, log_mode, + logged_isize, ctx); + if (ret < 0) + return ret; + ins_nr = 0; + } + btrfs_release_path(path); +next_key: + if (min_key->offset < (u64)-1) { + min_key->offset++; + } else if (min_key->type < max_key->type) { + min_key->type++; + min_key->offset = 0; + } else { + break; + } + + /* + * We may process many leaves full of items for our inode, so + * avoid monopolizing a cpu for too long by rescheduling while + * not holding locks on any tree. + */ + cond_resched(); + } + if (ins_nr) { + ret = copy_items(trans, inode, dst_path, path, ins_start_slot, + ins_nr, log_mode, logged_isize, ctx); + if (ret) + return ret; + } + + if (log_mode == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) { + /* + * Release the path because otherwise we might attempt to double + * lock the same leaf with btrfs_log_prealloc_extents() below. + */ + btrfs_release_path(path); + ret = btrfs_log_prealloc_extents(trans, inode, dst_path, ctx); + } + + return ret; +} + +static int insert_delayed_items_batch(struct btrfs_trans_handle *trans, + struct btrfs_root *log, + struct btrfs_path *path, + const struct btrfs_item_batch *batch, + const struct btrfs_delayed_item *first_item) +{ + const struct btrfs_delayed_item *curr = first_item; + int ret; + + ret = btrfs_insert_empty_items(trans, log, path, batch); + if (ret) + return ret; + + for (int i = 0; i < batch->nr; i++) { + char *data_ptr; + + data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char); + write_extent_buffer(path->nodes[0], &curr->data, + (unsigned long)data_ptr, curr->data_len); + curr = list_next_entry(curr, log_list); + path->slots[0]++; + } + + btrfs_release_path(path); + + return 0; +} + +static int log_delayed_insertion_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_ins_list, + struct btrfs_log_ctx *ctx) +{ + /* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */ + const int max_batch_size = 195; + const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info); + const u64 ino = btrfs_ino(inode); + struct btrfs_root *log = inode->root->log_root; + struct btrfs_item_batch batch = { + .nr = 0, + .total_data_size = 0, + }; + const struct btrfs_delayed_item *first = NULL; + const struct btrfs_delayed_item *curr; + char *ins_data; + struct btrfs_key *ins_keys; + u32 *ins_sizes; + u64 curr_batch_size = 0; + int batch_idx = 0; + int ret; + + /* We are adding dir index items to the log tree. */ + lockdep_assert_held(&inode->log_mutex); + + /* + * We collect delayed items before copying index keys from the subvolume + * to the log tree. However just after we collected them, they may have + * been flushed (all of them or just some of them), and therefore we + * could have copied them from the subvolume tree to the log tree. + * So find the first delayed item that was not yet logged (they are + * sorted by index number). + */ + list_for_each_entry(curr, delayed_ins_list, log_list) { + if (curr->index > inode->last_dir_index_offset) { + first = curr; + break; + } + } + + /* Empty list or all delayed items were already logged. */ + if (!first) + return 0; + + ins_data = kmalloc_array(max_batch_size, sizeof(u32) + sizeof(struct btrfs_key), GFP_NOFS); + if (!ins_data) + return -ENOMEM; + ins_sizes = (u32 *)ins_data; + batch.data_sizes = ins_sizes; + ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32)); + batch.keys = ins_keys; + + curr = first; + while (!list_entry_is_head(curr, delayed_ins_list, log_list)) { + const u32 curr_size = curr->data_len + sizeof(struct btrfs_item); + + if (curr_batch_size + curr_size > leaf_data_size || + batch.nr == max_batch_size) { + ret = insert_delayed_items_batch(trans, log, path, + &batch, first); + if (ret) + goto out; + batch_idx = 0; + batch.nr = 0; + batch.total_data_size = 0; + curr_batch_size = 0; + first = curr; + } + + ins_sizes[batch_idx] = curr->data_len; + ins_keys[batch_idx].objectid = ino; + ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY; + ins_keys[batch_idx].offset = curr->index; + curr_batch_size += curr_size; + batch.total_data_size += curr->data_len; + batch.nr++; + batch_idx++; + curr = list_next_entry(curr, log_list); + } + + ASSERT(batch.nr >= 1, "batch.nr=%d", batch.nr); + ret = insert_delayed_items_batch(trans, log, path, &batch, first); + + curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item, + log_list); + inode->last_dir_index_offset = curr->index; +out: + kfree(ins_data); + + return ret; +} + +static int log_delayed_deletions_full(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + const u64 ino = btrfs_ino(inode); + const struct btrfs_delayed_item *curr; + + curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item, + log_list); + + while (!list_entry_is_head(curr, delayed_del_list, log_list)) { + u64 first_dir_index = curr->index; + u64 last_dir_index; + const struct btrfs_delayed_item *next; + int ret; + + /* + * Find a range of consecutive dir index items to delete. Like + * this we log a single dir range item spanning several contiguous + * dir items instead of logging one range item per dir index item. + */ + next = list_next_entry(curr, log_list); + while (!list_entry_is_head(next, delayed_del_list, log_list)) { + if (next->index != curr->index + 1) + break; + curr = next; + next = list_next_entry(next, log_list); + } + + last_dir_index = curr->index; + ASSERT(last_dir_index >= first_dir_index, + "last_dir_index=%llu first_dir_index=%llu", + last_dir_index, first_dir_index); + + ret = insert_dir_log_key(trans, inode->root->log_root, path, + ino, first_dir_index, last_dir_index); + if (ret) + return ret; + curr = list_next_entry(curr, log_list); + } + + return 0; +} + +static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + const struct btrfs_delayed_item *first, + const struct btrfs_delayed_item **last_ret) +{ + const struct btrfs_delayed_item *next; + struct extent_buffer *leaf = path->nodes[0]; + const int last_slot = btrfs_header_nritems(leaf) - 1; + int slot = path->slots[0] + 1; + const u64 ino = btrfs_ino(inode); + + next = list_next_entry(first, log_list); + + while (slot < last_slot && + !list_entry_is_head(next, delayed_del_list, log_list)) { + struct btrfs_key key; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != ino || + key.type != BTRFS_DIR_INDEX_KEY || + key.offset != next->index) + break; + + slot++; + *last_ret = next; + next = list_next_entry(next, log_list); + } + + return btrfs_del_items(trans, inode->root->log_root, path, + path->slots[0], slot - path->slots[0]); +} + +static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *log = inode->root->log_root; + const struct btrfs_delayed_item *curr; + u64 last_range_start = 0; + u64 last_range_end = 0; + struct btrfs_key key; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_DIR_INDEX_KEY; + curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item, + log_list); + + while (!list_entry_is_head(curr, delayed_del_list, log_list)) { + const struct btrfs_delayed_item *last = curr; + u64 first_dir_index = curr->index; + u64 last_dir_index; + bool deleted_items = false; + int ret; + + key.offset = curr->index; + ret = btrfs_search_slot(trans, log, &key, path, -1, 1); + if (ret < 0) { + return ret; + } else if (ret == 0) { + ret = batch_delete_dir_index_items(trans, inode, path, + delayed_del_list, curr, + &last); + if (ret) + return ret; + deleted_items = true; + } + + btrfs_release_path(path); + + /* + * If we deleted items from the leaf, it means we have a range + * item logging their range, so no need to add one or update an + * existing one. Otherwise we have to log a dir range item. + */ + if (deleted_items) + goto next_batch; + + last_dir_index = last->index; + ASSERT(last_dir_index >= first_dir_index, + "last_dir_index=%llu first_dir_index=%llu", + last_dir_index, first_dir_index); + /* + * If this range starts right after where the previous one ends, + * then we want to reuse the previous range item and change its + * end offset to the end of this range. This is just to minimize + * leaf space usage, by avoiding adding a new range item. + */ + if (last_range_end != 0 && first_dir_index == last_range_end + 1) + first_dir_index = last_range_start; + + ret = insert_dir_log_key(trans, log, path, key.objectid, + first_dir_index, last_dir_index); + if (ret) + return ret; + + last_range_start = first_dir_index; + last_range_end = last_dir_index; +next_batch: + curr = list_next_entry(last, log_list); + } + + return 0; +} + +static int log_delayed_deletion_items(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_path *path, + const struct list_head *delayed_del_list, + struct btrfs_log_ctx *ctx) +{ + /* + * We are deleting dir index items from the log tree or adding range + * items to it. + */ + lockdep_assert_held(&inode->log_mutex); + + if (list_empty(delayed_del_list)) + return 0; + + if (ctx->logged_before) + return log_delayed_deletions_incremental(trans, inode, path, + delayed_del_list, ctx); + + return log_delayed_deletions_full(trans, inode, path, delayed_del_list, + ctx); +} + +/* + * Similar logic as for log_new_dir_dentries(), but it iterates over the delayed + * items instead of the subvolume tree. + */ +static int log_new_delayed_dentries(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + const struct list_head *delayed_ins_list, + struct btrfs_log_ctx *ctx) +{ + const bool orig_log_new_dentries = ctx->log_new_dentries; + struct btrfs_delayed_item *item; + int ret = 0; + + /* + * No need for the log mutex, plus to avoid potential deadlocks or + * lockdep annotations due to nesting of delayed inode mutexes and log + * mutexes. + */ + lockdep_assert_not_held(&inode->log_mutex); + + ASSERT(!ctx->logging_new_delayed_dentries); + + /* + * Return early if empty list, avoid emitting redundant trace events + * that generate noise only. + */ + if (list_empty(delayed_ins_list)) + return 0; + + trace_btrfs_log_new_delayed_dentries_enter(trans, inode); + ctx->logging_new_delayed_dentries = true; + + list_for_each_entry(item, delayed_ins_list, log_list) { + struct btrfs_dir_item *dir_item; + struct btrfs_inode *di_inode; + struct btrfs_key key; + int log_mode = LOG_INODE_EXISTS; + + dir_item = (struct btrfs_dir_item *)item->data; + btrfs_disk_key_to_cpu(&key, &dir_item->location); + + if (key.type == BTRFS_ROOT_ITEM_KEY) + continue; + + di_inode = btrfs_iget_logging(key.objectid, inode->root); + if (IS_ERR(di_inode)) { + ret = PTR_ERR(di_inode); + break; + } + + if (!need_log_inode(trans, di_inode)) { + btrfs_add_delayed_iput(di_inode); + continue; + } + + if (btrfs_stack_dir_ftype(dir_item) == BTRFS_FT_DIR) + log_mode = LOG_INODE_ALL; + + ctx->log_new_dentries = false; + ret = btrfs_log_inode(trans, di_inode, log_mode, ctx); + + if (!ret && ctx->log_new_dentries) + ret = log_new_dir_dentries(trans, di_inode, ctx); + + btrfs_add_delayed_iput(di_inode); + + if (ret) + break; + } + + ctx->log_new_dentries = orig_log_new_dentries; + ctx->logging_new_delayed_dentries = false; + trace_btrfs_log_new_delayed_dentries_exit(trans, inode, ret); + + return ret; +} + +/* log a single inode in the tree log. + * At least one parent directory for this inode must exist in the tree + * or be logged already. + * + * Any items from this inode changed by the current transaction are copied + * to the log tree. An extra reference is taken on any extents in this + * file, allowing us to avoid a whole pile of corner cases around logging + * blocks that have been removed from the tree. + * + * See LOG_INODE_ALL and related defines for a description of what inode_only + * does. + * + * This handles both files and directories. + */ +static int btrfs_log_inode(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + enum btrfs_log_mode log_mode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_path *path; + struct btrfs_path *dst_path = NULL; + struct btrfs_key min_key; + struct btrfs_key max_key; + struct btrfs_root *log = inode->root->log_root; + int ret; + bool fast_search = false; + u64 ino = btrfs_ino(inode); + struct extent_map_tree *em_tree = &inode->extent_tree; + u64 logged_isize = 0; + bool need_log_inode_item = true; + bool xattrs_logged = false; + bool inode_item_dropped = true; + bool full_dir_logging = false; + LIST_HEAD(delayed_ins_list); + LIST_HEAD(delayed_del_list); + + trace_btrfs_log_inode_enter(trans, inode, ctx, log_mode); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + + min_key.objectid = ino; + min_key.type = BTRFS_INODE_ITEM_KEY; + min_key.offset = 0; + + max_key.objectid = ino; + + + /* today the code can only do partial logging of directories */ + if (S_ISDIR(inode->vfs_inode.i_mode) || + (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &inode->runtime_flags) && + log_mode >= LOG_INODE_EXISTS)) + max_key.type = BTRFS_XATTR_ITEM_KEY; + else + max_key.type = (u8)-1; + max_key.offset = (u64)-1; + + if (S_ISDIR(inode->vfs_inode.i_mode) && log_mode == LOG_INODE_ALL) + full_dir_logging = true; + + /* + * If we are logging a directory while we are logging dentries of the + * delayed items of some other inode, then we need to flush the delayed + * items of this directory and not log the delayed items directly. This + * is to prevent more than one level of recursion into btrfs_log_inode() + * by having something like this: + * + * $ mkdir -p a/b/c/d/e/f/g/h/... + * $ xfs_io -c "fsync" a + * + * Where all directories in the path did not exist before and are + * created in the current transaction. + * So in such a case we directly log the delayed items of the main + * directory ("a") without flushing them first, while for each of its + * subdirectories we flush their delayed items before logging them. + * This prevents a potential unbounded recursion like this: + * + * btrfs_log_inode() + * log_new_delayed_dentries() + * btrfs_log_inode() + * log_new_delayed_dentries() + * btrfs_log_inode() + * log_new_delayed_dentries() + * (...) + * + * We have thresholds for the maximum number of delayed items to have in + * memory, and once they are hit, the items are flushed asynchronously. + * However the limit is quite high, so lets prevent deep levels of + * recursion to happen by limiting the maximum depth to be 1. + */ + if (full_dir_logging && ctx->logging_new_delayed_dentries) { + ret = btrfs_commit_inode_delayed_items(trans, inode); + if (ret) + goto out; + } + + mutex_lock(&inode->log_mutex); + + /* + * For symlinks, we must always log their content, which is stored in an + * inline extent, otherwise we could end up with an empty symlink after + * log replay, which is invalid on linux (symlink(2) returns -ENOENT if + * one attempts to create an empty symlink). + * We don't need to worry about flushing delalloc, because when we create + * the inline extent when the symlink is created (we never have delalloc + * for symlinks). + */ + if (S_ISLNK(inode->vfs_inode.i_mode)) + log_mode = LOG_INODE_ALL; + + /* + * Before logging the inode item, cache the value returned by + * inode_logged(), because after that we have the need to figure out if + * the inode was previously logged in this transaction. + */ + ret = inode_logged(trans, inode, path); + if (ret < 0) + goto out_unlock; + ctx->logged_before = (ret == 1); + ret = 0; + + /* + * This is for cases where logging a directory could result in losing a + * a file after replaying the log. For example, if we move a file from a + * directory A to a directory B, then fsync directory A, we have no way + * to known the file was moved from A to B, so logging just A would + * result in losing the file after a log replay. + */ + if (full_dir_logging && inode->last_unlink_trans >= trans->transid) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out_unlock; + } + + /* + * a brute force approach to making sure we get the most uptodate + * copies of everything. + */ + if (S_ISDIR(inode->vfs_inode.i_mode)) { + clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags); + if (ctx->logged_before) + ret = drop_inode_items(trans, log, path, inode, + BTRFS_XATTR_ITEM_KEY); + } else { + if (log_mode == LOG_INODE_EXISTS) { + /* + * Make sure the new inode item we write to the log has + * the same isize as the current one (if it exists). + * This is necessary to prevent data loss after log + * replay, and also to prevent doing a wrong expanding + * truncate - for e.g. create file, write 4K into offset + * 0, fsync, write 4K into offset 4096, add hard link, + * fsync some other file (to sync log), power fail - if + * we use the inode's current i_size, after log replay + * we get a 8Kb file, with the last 4Kb extent as a hole + * (zeroes), as if an expanding truncate happened, + * instead of getting a file of 4Kb only. + */ + ret = get_inode_size_to_log(trans, inode, path, &logged_isize); + if (ret) + goto out_unlock; + } + if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &inode->runtime_flags)) { + if (log_mode == LOG_INODE_EXISTS) { + max_key.type = BTRFS_XATTR_ITEM_KEY; + if (ctx->logged_before) + ret = drop_inode_items(trans, log, path, + inode, max_key.type); + } else { + clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &inode->runtime_flags); + clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &inode->runtime_flags); + if (ctx->logged_before) + ret = truncate_inode_items(trans, log, + inode, 0, 0); + } + } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING, + &inode->runtime_flags) || + log_mode == LOG_INODE_EXISTS) { + if (log_mode == LOG_INODE_ALL) + fast_search = true; + max_key.type = BTRFS_XATTR_ITEM_KEY; + if (ctx->logged_before) + ret = drop_inode_items(trans, log, path, inode, + max_key.type); + } else { + if (log_mode == LOG_INODE_ALL) + fast_search = true; + inode_item_dropped = false; + goto log_extents; + } + + } + if (ret) + goto out_unlock; + + /* + * If we are logging a directory in full mode, collect the delayed items + * before iterating the subvolume tree, so that we don't miss any new + * dir index items in case they get flushed while or right after we are + * iterating the subvolume tree. + */ + if (full_dir_logging && !ctx->logging_new_delayed_dentries) + btrfs_log_get_delayed_items(inode, &delayed_ins_list, + &delayed_del_list); + + /* + * If we are fsyncing a file with 0 hard links, then commit the delayed + * inode because the last inode ref (or extref) item may still be in the + * subvolume tree and if we log it the file will still exist after a log + * replay. So commit the delayed inode to delete that last ref and we + * skip logging it. + */ + if (inode->vfs_inode.i_nlink == 0) { + ret = btrfs_commit_inode_delayed_inode(inode); + if (ret) + goto out_unlock; + } + + ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key, + path, dst_path, logged_isize, + log_mode, ctx, &need_log_inode_item); + if (ret) + goto out_unlock; + + btrfs_release_path(path); + btrfs_release_path(dst_path); + ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx); + if (ret) + goto out_unlock; + xattrs_logged = true; + if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) { + btrfs_release_path(path); + btrfs_release_path(dst_path); + ret = btrfs_log_holes(trans, inode, path); + if (ret) + goto out_unlock; + } +log_extents: + btrfs_release_path(path); + btrfs_release_path(dst_path); + if (need_log_inode_item) { + ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped); + if (ret) + goto out_unlock; + /* + * If we are doing a fast fsync and the inode was logged before + * in this transaction, we don't need to log the xattrs because + * they were logged before. If xattrs were added, changed or + * deleted since the last time we logged the inode, then we have + * already logged them because the inode had the runtime flag + * BTRFS_INODE_COPY_EVERYTHING set. + */ + if (!xattrs_logged && inode->logged_trans < trans->transid) { + ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx); + if (ret) + goto out_unlock; + btrfs_release_path(path); + } + } + if (fast_search) { + ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx); + if (ret) + goto out_unlock; + } else if (log_mode == LOG_INODE_ALL) { + struct extent_map *em, *n; + + write_lock(&em_tree->lock); + list_for_each_entry_safe(em, n, &em_tree->modified_extents, list) + list_del_init(&em->list); + write_unlock(&em_tree->lock); + } + + if (full_dir_logging) { + ret = log_directory_changes(trans, inode, path, dst_path, ctx); + if (ret) + goto out_unlock; + ret = log_delayed_insertion_items(trans, inode, path, + &delayed_ins_list, ctx); + if (ret) + goto out_unlock; + ret = log_delayed_deletion_items(trans, inode, path, + &delayed_del_list, ctx); + if (ret) + goto out_unlock; + } + + spin_lock(&inode->lock); + inode->logged_trans = trans->transid; + /* + * Don't update last_log_commit if we logged that an inode exists. + * We do this for three reasons: + * + * 1) We might have had buffered writes to this inode that were + * flushed and had their ordered extents completed in this + * transaction, but we did not previously log the inode with + * LOG_INODE_ALL. Later the inode was evicted and after that + * it was loaded again and this LOG_INODE_EXISTS log operation + * happened. We must make sure that if an explicit fsync against + * the inode is performed later, it logs the new extents, an + * updated inode item, etc, and syncs the log. The same logic + * applies to direct IO writes instead of buffered writes. + * + * 2) When we log the inode with LOG_INODE_EXISTS, its inode item + * is logged with an i_size of 0 or whatever value was logged + * before. If later the i_size of the inode is increased by a + * truncate operation, the log is synced through an fsync of + * some other inode and then finally an explicit fsync against + * this inode is made, we must make sure this fsync logs the + * inode with the new i_size, the hole between old i_size and + * the new i_size, and syncs the log. + * + * 3) If we are logging that an ancestor inode exists as part of + * logging a new name from a link or rename operation, don't update + * its last_log_commit - otherwise if an explicit fsync is made + * against an ancestor, the fsync considers the inode in the log + * and doesn't sync the log, resulting in the ancestor missing after + * a power failure unless the log was synced as part of an fsync + * against any other unrelated inode. + */ + if (!ctx->logging_new_name && log_mode != LOG_INODE_EXISTS) + inode->last_log_commit = inode->last_sub_trans; + spin_unlock(&inode->lock); + + /* + * Reset the last_reflink_trans so that the next fsync does not need to + * go through the slower path when logging extents and their checksums. + */ + if (log_mode == LOG_INODE_ALL) + inode->last_reflink_trans = 0; + +out_unlock: + mutex_unlock(&inode->log_mutex); +out: + btrfs_free_path(path); + btrfs_free_path(dst_path); + + if (ret) + free_conflicting_inodes(ctx); + else + ret = log_conflicting_inodes(trans, inode->root, ctx); + + if (full_dir_logging && !ctx->logging_new_delayed_dentries) { + if (!ret) + ret = log_new_delayed_dentries(trans, inode, + &delayed_ins_list, ctx); + + btrfs_log_put_delayed_items(inode, &delayed_ins_list, + &delayed_del_list); + } + + trace_btrfs_log_inode_exit(trans, inode, ret); + + return ret; +} + +static int btrfs_log_all_parents(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct btrfs_log_ctx *ctx) +{ + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct btrfs_root *root = inode->root; + const u64 ino = btrfs_ino(inode); + + trace_btrfs_log_all_parents_enter(trans, inode); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + path->skip_locking = true; + path->search_commit_root = true; + + key.objectid = ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + u32 cur_offset = 0; + u32 item_size; + unsigned long ptr; + + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, slot); + /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */ + if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY) + break; + + item_size = btrfs_item_size(leaf, slot); + ptr = btrfs_item_ptr_offset(leaf, slot); + while (cur_offset < item_size) { + u64 dir_id; + struct btrfs_inode *dir_inode; + + if (key.type == BTRFS_INODE_EXTREF_KEY) { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *) + (ptr + cur_offset); + dir_id = btrfs_inode_extref_parent(leaf, extref); + cur_offset += sizeof(*extref); + cur_offset += btrfs_inode_extref_name_len(leaf, + extref); + } else { + dir_id = key.offset; + cur_offset = item_size; + } + + dir_inode = btrfs_iget_logging(dir_id, root); + /* + * If the parent inode was deleted, return an error to + * fallback to a transaction commit. This is to prevent + * getting an inode that was moved from one parent A to + * a parent B, got its former parent A deleted and then + * it got fsync'ed, from existing at both parents after + * a log replay (and the old parent still existing). + * Example: + * + * mkdir /mnt/A + * mkdir /mnt/B + * touch /mnt/B/bar + * sync + * mv /mnt/B/bar /mnt/A/bar + * mv -T /mnt/A /mnt/B + * fsync /mnt/B/bar + * <power fail> + * + * If we ignore the old parent B which got deleted, + * after a log replay we would have file bar linked + * at both parents and the old parent B would still + * exist. + */ + if (IS_ERR(dir_inode)) { + ret = PTR_ERR(dir_inode); + goto out; + } + + if (!need_log_inode(trans, dir_inode)) { + btrfs_add_delayed_iput(dir_inode); + continue; + } + + ctx->log_new_dentries = false; + ret = btrfs_log_inode(trans, dir_inode, LOG_INODE_ALL, ctx); + if (!ret && ctx->log_new_dentries) + ret = log_new_dir_dentries(trans, dir_inode, ctx); + btrfs_add_delayed_iput(dir_inode); + if (ret) + goto out; + } + path->slots[0]++; + } +out: + trace_btrfs_log_all_parents_exit(trans, inode, ret); + + return ret; +} + +static int log_new_ancestors(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_key found_key; + + btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]); + + while (true) { + struct extent_buffer *leaf; + int slot; + struct btrfs_key search_key; + struct btrfs_inode *inode; + u64 ino; + int ret = 0; + + btrfs_release_path(path); + + ino = found_key.offset; + + search_key.objectid = found_key.offset; + search_key.type = BTRFS_INODE_ITEM_KEY; + search_key.offset = 0; + inode = btrfs_iget_logging(ino, root); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + if (inode->generation >= trans->transid && + need_log_inode(trans, inode)) + ret = btrfs_log_inode(trans, inode, LOG_INODE_EXISTS, ctx); + btrfs_add_delayed_iput(inode); + if (ret) + return ret; + + if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID) + break; + + search_key.type = BTRFS_INODE_REF_KEY; + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + return ret; + + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + else if (ret > 0) + return -ENOENT; + leaf = path->nodes[0]; + slot = path->slots[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, slot); + if (found_key.objectid != search_key.objectid || + found_key.type != BTRFS_INODE_REF_KEY) + return -ENOENT; + } + return 0; +} + +static int log_new_ancestors_fast(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct dentry *parent, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + struct dentry *old_parent = NULL; + struct super_block *sb = inode->vfs_inode.i_sb; + int ret = 0; + + while (true) { + if (!parent || d_really_is_negative(parent) || + sb != parent->d_sb) + break; + + inode = BTRFS_I(d_inode(parent)); + if (root != inode->root) + break; + + if (inode->generation >= trans->transid && + need_log_inode(trans, inode)) { + ret = btrfs_log_inode(trans, inode, + LOG_INODE_EXISTS, ctx); + if (ret) + break; + } + if (IS_ROOT(parent)) + break; + + parent = dget_parent(parent); + dput(old_parent); + old_parent = parent; + } + dput(old_parent); + + return ret; +} + +static int log_all_new_ancestors(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct dentry *parent, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + const u64 ino = btrfs_ino(inode); + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key search_key; + int ret; + + trace_btrfs_log_all_new_ancestors_enter(trans, inode); + + /* + * For a single hard link case, go through a fast path that does not + * need to iterate the fs/subvolume tree. + */ + if (inode->vfs_inode.i_nlink < 2) { + ret = log_new_ancestors_fast(trans, inode, parent, ctx); + goto out; + } + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + search_key.objectid = ino; + search_key.type = BTRFS_INODE_REF_KEY; + search_key.offset = 0; +again: + ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0); + if (ret < 0) + goto out; + if (ret == 0) + path->slots[0]++; + + while (true) { + struct extent_buffer *leaf = path->nodes[0]; + int slot = path->slots[0]; + struct btrfs_key found_key; + + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + if (ret > 0) { + ret = 0; + break; + } + continue; + } + + btrfs_item_key_to_cpu(leaf, &found_key, slot); + if (found_key.objectid != ino || + found_key.type > BTRFS_INODE_EXTREF_KEY) + break; + + /* + * Don't deal with extended references because they are rare + * cases and too complex to deal with (we would need to keep + * track of which subitem we are processing for each item in + * this loop, etc). So just return some error to fallback to + * a transaction commit. + */ + if (found_key.type == BTRFS_INODE_EXTREF_KEY) { + ret = -EMLINK; + goto out; + } + + /* + * Logging ancestors needs to do more searches on the fs/subvol + * tree, so it releases the path as needed to avoid deadlocks. + * Keep track of the last inode ref key and resume from that key + * after logging all new ancestors for the current hard link. + */ + memcpy(&search_key, &found_key, sizeof(search_key)); + + ret = log_new_ancestors(trans, root, path, ctx); + if (ret) + goto out; + btrfs_release_path(path); + goto again; + } +out: + trace_btrfs_log_all_new_ancestors_exit(trans, inode, ret); + return ret; +} + +/* + * helper function around btrfs_log_inode to make sure newly created + * parent directories also end up in the log. A minimal inode and backref + * only logging is done of any parent directories that are older than + * the last committed transaction + */ +static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, + struct dentry *parent, + enum btrfs_log_mode log_mode, + struct btrfs_log_ctx *ctx) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + int ret = 0; + bool log_dentries; + + trace_btrfs_log_inode_parent_enter(trans, inode); + + if (btrfs_test_opt(fs_info, NOTREELOG)) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + if (btrfs_root_refs(&root->root_item) == 0) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + /* + * If we're logging an inode from a subvolume created in the current + * transaction we must force a commit since the root is not persisted. + */ + if (btrfs_root_generation(&root->root_item) == trans->transid) { + ret = BTRFS_LOG_FORCE_COMMIT; + goto out; + } + + /* Skip already logged inodes and without new extents. */ + if (btrfs_inode_in_log(inode, trans->transid) && + list_empty(&ctx->ordered_extents)) { + ret = BTRFS_NO_LOG_SYNC; + goto out; + } + + ret = start_log_trans(trans, root, ctx); + if (ret) + goto out; + + ret = btrfs_log_inode(trans, inode, log_mode, ctx); + if (ret) + goto end_trans; + + /* + * for regular files, if its inode is already on disk, we don't + * have to worry about the parents at all. This is because + * we can use the last_unlink_trans field to record renames + * and other fun in this file. + */ + if (S_ISREG(inode->vfs_inode.i_mode) && + inode->generation < trans->transid && + inode->last_unlink_trans < trans->transid) { + ret = 0; + goto end_trans; + } + + /* + * Track if we need to log dentries because ctx->log_new_dentries can + * be modified in the call chains below. + */ + log_dentries = ctx->log_new_dentries; + + /* + * On unlink we must make sure all our current and old parent directory + * inodes are fully logged. This is to prevent leaving dangling + * directory index entries in directories that were our parents but are + * not anymore. Not doing this results in old parent directory being + * impossible to delete after log replay (rmdir will always fail with + * error -ENOTEMPTY). + * + * Example 1: + * + * mkdir testdir + * touch testdir/foo + * ln testdir/foo testdir/bar + * sync + * unlink testdir/bar + * xfs_io -c fsync testdir/foo + * <power failure> + * mount fs, triggers log replay + * + * If we don't log the parent directory (testdir), after log replay the + * directory still has an entry pointing to the file inode using the bar + * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and + * the file inode has a link count of 1. + * + * Example 2: + * + * mkdir testdir + * touch foo + * ln foo testdir/foo2 + * ln foo testdir/foo3 + * sync + * unlink testdir/foo3 + * xfs_io -c fsync foo + * <power failure> + * mount fs, triggers log replay + * + * Similar as the first example, after log replay the parent directory + * testdir still has an entry pointing to the inode file with name foo3 + * but the file inode does not have a matching BTRFS_INODE_REF_KEY item + * and has a link count of 2. + */ + if (inode->last_unlink_trans >= trans->transid) { + ret = btrfs_log_all_parents(trans, inode, ctx); + if (ret) + goto end_trans; + } + + ret = log_all_new_ancestors(trans, inode, parent, ctx); + if (ret) + goto end_trans; + + if (log_dentries) + ret = log_new_dir_dentries(trans, inode, ctx); +end_trans: + if (ret < 0) { + btrfs_set_log_full_commit(trans); + ret = BTRFS_LOG_FORCE_COMMIT; + } + + if (ret) + btrfs_remove_log_ctx(root, ctx); + btrfs_end_log_trans(root); + +out: + trace_btrfs_log_inode_parent_exit(trans, inode, ret); + + return ret; +} + +/* + * it is not safe to log dentry if the chunk root has added new + * chunks. This returns 0 if the dentry was logged, and 1 otherwise. + * If this returns 1, you must commit the transaction to safely get your + * data on disk. + */ +int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans, + struct dentry *dentry, + struct btrfs_log_ctx *ctx) +{ + struct dentry *parent = dget_parent(dentry); + int ret; + + ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent, + LOG_INODE_ALL, ctx); + dput(parent); + + return ret; +} + +/* + * should be called during mount to recover any replay any log trees + * from the FS + */ +int btrfs_recover_log_trees(struct btrfs_root *log_root_tree) +{ + int ret; + struct btrfs_path *path; + struct btrfs_trans_handle *trans; + struct btrfs_key key; + struct btrfs_fs_info *fs_info = log_root_tree->fs_info; + struct walk_control wc = { + .process_func = process_one_buffer, + .stage = LOG_WALK_PIN_ONLY, + }; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + + trans = btrfs_start_transaction(fs_info->tree_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto error; + } + + wc.trans = trans; + wc.pin = true; + wc.log = log_root_tree; + + ret = walk_log_tree(&wc); + wc.log = NULL; + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto error; + } + +again: + key.objectid = BTRFS_TREE_LOG_OBJECTID; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = (u64)-1; + + while (1) { + struct btrfs_key found_key; + + ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0); + + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto error; + } + if (ret > 0) { + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + btrfs_release_path(path); + if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID) + break; + + wc.log = btrfs_read_tree_root(log_root_tree, &found_key); + if (IS_ERR(wc.log)) { + ret = PTR_ERR(wc.log); + wc.log = NULL; + btrfs_abort_transaction(trans, ret); + goto error; + } + + wc.root = btrfs_get_fs_root(fs_info, found_key.offset, true); + if (IS_ERR(wc.root)) { + ret = PTR_ERR(wc.root); + wc.root = NULL; + if (unlikely(ret != -ENOENT)) { + btrfs_abort_transaction(trans, ret); + goto error; + } + + /* + * We didn't find the subvol, likely because it was + * deleted. This is ok, simply skip this log and go to + * the next one. + * + * We need to exclude the root because we can't have + * other log replays overwriting this log as we'll read + * it back in a few more times. This will keep our + * block from being modified, and we'll just bail for + * each subsequent pass. + */ + ret = btrfs_pin_extent_for_log_replay(trans, wc.log->node); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto error; + } + goto next; + } + + wc.root->log_root = wc.log; + ret = btrfs_record_root_in_trans(trans, wc.root); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto next; + } + + ret = walk_log_tree(&wc); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto next; + } + + if (wc.stage == LOG_WALK_REPLAY_ALL) { + struct btrfs_root *root = wc.root; + + wc.subvol_path = path; + ret = fixup_inode_link_counts(&wc); + wc.subvol_path = NULL; + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto next; + } + /* + * We have just replayed everything, and the highest + * objectid of fs roots probably has changed in case + * some inode_item's got replayed. + * + * root->objectid_mutex is not acquired as log replay + * could only happen during mount. + */ + ret = btrfs_init_root_free_objectid(root); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto next; + } + } +next: + if (wc.root) { + wc.root->log_root = NULL; + btrfs_put_root(wc.root); + } + btrfs_put_root(wc.log); + wc.log = NULL; + + if (ret) + goto error; + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + btrfs_release_path(path); + + /* step one is to pin it all, step two is to replay just inodes */ + if (wc.pin) { + wc.pin = false; + wc.process_func = replay_one_buffer; + wc.stage = LOG_WALK_REPLAY_INODES; + goto again; + } + /* step three is to replay everything */ + if (wc.stage < LOG_WALK_REPLAY_ALL) { + wc.stage++; + goto again; + } + + btrfs_free_path(path); + + /* step 4: commit the transaction, which also unpins the blocks */ + ret = btrfs_commit_transaction(trans); + if (ret) + return ret; + + clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + + return 0; +error: + if (wc.trans) + btrfs_end_transaction(wc.trans); + btrfs_put_root(wc.log); + clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags); + btrfs_free_path(path); + return ret; +} + +/* + * there are some corner cases where we want to force a full + * commit instead of allowing a directory to be logged. + * + * They revolve around files there were unlinked from the directory, and + * this function updates the parent directory so that a full commit is + * properly done if it is fsync'd later after the unlinks are done. + * + * Must be called before the unlink operations (updates to the subvolume tree, + * inodes, etc) are done. + */ +void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir, struct btrfs_inode *inode, + bool for_rename) +{ + trace_btrfs_record_unlink_dir(trans, dir, inode, for_rename); + + /* + * when we're logging a file, if it hasn't been renamed + * or unlinked, and its inode is fully committed on disk, + * we don't have to worry about walking up the directory chain + * to log its parents. + * + * So, we use the last_unlink_trans field to put this transid + * into the file. When the file is logged we check it and + * don't log the parents if the file is fully on disk. + */ + mutex_lock(&inode->log_mutex); + inode->last_unlink_trans = trans->transid; + mutex_unlock(&inode->log_mutex); + + if (!for_rename) + return; + + /* + * If this directory was already logged, any new names will be logged + * with btrfs_log_new_name() and old names will be deleted from the log + * tree with btrfs_del_dir_entries_in_log() or with + * btrfs_del_inode_ref_in_log(). + */ + if (inode_logged(trans, dir, NULL) == 1) + return; + + /* + * If the inode we're about to unlink was logged before, the log will be + * properly updated with the new name with btrfs_log_new_name() and the + * old name removed with btrfs_del_dir_entries_in_log() or with + * btrfs_del_inode_ref_in_log(). + */ + if (inode_logged(trans, inode, NULL) == 1) + return; + + /* + * when renaming files across directories, if the directory + * there we're unlinking from gets fsync'd later on, there's + * no way to find the destination directory later and fsync it + * properly. So, we have to be conservative and force commits + * so the new name gets discovered. + */ + mutex_lock(&dir->log_mutex); + dir->last_unlink_trans = trans->transid; + mutex_unlock(&dir->log_mutex); +} + +/* + * Make sure that if someone attempts to fsync the parent directory of a deleted + * snapshot, it ends up triggering a transaction commit. This is to guarantee + * that after replaying the log tree of the parent directory's root we will not + * see the snapshot anymore and at log replay time we will not see any log tree + * corresponding to the deleted snapshot's root, which could lead to replaying + * it after replaying the log tree of the parent directory (which would replay + * the snapshot delete operation). + * + * Must be called before the actual snapshot destroy operation (updates to the + * parent root and tree of tree roots trees, etc) are done. + */ +void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir) +{ + trace_btrfs_record_snapshot_destroy(trans, dir); + + mutex_lock(&dir->log_mutex); + dir->last_unlink_trans = trans->transid; + mutex_unlock(&dir->log_mutex); +} + +/* + * Call this when creating a subvolume in a directory. + * Because we don't commit a transaction when creating a subvolume, we can't + * allow the directory pointing to the subvolume to be logged with an entry that + * points to an unpersisted root if we are still in the transaction used to + * create the subvolume, so make any attempt to log the directory to result in a + * full log sync. + * Also we don't need to worry with renames, since btrfs_rename() marks the log + * for full commit when renaming a subvolume. + * + * Must be called before creating the subvolume entry in its parent directory. + */ +void btrfs_record_new_subvolume(const struct btrfs_trans_handle *trans, + struct btrfs_inode *dir) +{ + trace_btrfs_record_new_subvolume(trans, dir); + + mutex_lock(&dir->log_mutex); + dir->last_unlink_trans = trans->transid; + mutex_unlock(&dir->log_mutex); +} + +/* + * Update the log after adding a new name for an inode. + * + * @trans: Transaction handle. + * @old_dentry: The dentry associated with the old name and the old + * parent directory. + * @old_dir: The inode of the previous parent directory for the case + * of a rename. For a link operation, it must be NULL. + * @old_dir_index: The index number associated with the old name, meaningful + * only for rename operations (when @old_dir is not NULL). + * Ignored for link operations. + * @parent: The dentry associated with the directory under which the + * new name is located. + * + * Call this after adding a new name for an inode, as a result of a link or + * rename operation, and it will properly update the log to reflect the new name. + */ +void btrfs_log_new_name(struct btrfs_trans_handle *trans, + struct dentry *old_dentry, struct btrfs_inode *old_dir, + u64 old_dir_index, struct dentry *parent) +{ + struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry)); + struct btrfs_root *root = inode->root; + struct btrfs_log_ctx ctx; + bool log_pinned = false; + int ret; + + trace_btrfs_log_new_name_enter(trans, inode, old_dir, old_dir_index); + + /* The inode has a new name (ref/extref), so make sure we log it. */ + set_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags); + + btrfs_init_log_ctx(&ctx, inode); + ctx.logging_new_name = true; + + /* + * this will force the logging code to walk the dentry chain + * up for the file + */ + if (!S_ISDIR(inode->vfs_inode.i_mode)) + inode->last_unlink_trans = trans->transid; + + /* + * if this inode hasn't been logged and directory we're renaming it + * from hasn't been logged, we don't need to log it + */ + ret = inode_logged(trans, inode, NULL); + if (ret < 0) { + goto out; + } else if (ret == 0) { + if (!old_dir) + goto out; + /* + * If the inode was not logged and we are doing a rename (old_dir is not + * NULL), check if old_dir was logged - if it was not we can return and + * do nothing. + */ + ret = inode_logged(trans, old_dir, NULL); + if (ret < 0) + goto out; + else if (ret == 0) + goto out; + } + ret = 0; + + /* + * Now that we know we need to update the log, allocate the scratch eb + * for the context before joining a log transaction below, as this can + * take time and therefore we could delay log commits from other tasks. + */ + btrfs_init_log_ctx_scratch_eb(&ctx); + + /* + * If we are doing a rename (old_dir is not NULL) from a directory that + * was previously logged, make sure that on log replay we get the old + * dir entry deleted. This is needed because we will also log the new + * name of the renamed inode, so we need to make sure that after log + * replay we don't end up with both the new and old dir entries existing. + */ + if (old_dir && old_dir->logged_trans == trans->transid) { + struct btrfs_root *log = old_dir->root->log_root; + struct btrfs_path *path; + struct fscrypt_name fname; + + ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX, + "old_dir_index=%llu", old_dir_index); + + ret = fscrypt_setup_filename(&old_dir->vfs_inode, + &old_dentry->d_name, 0, &fname); + if (ret) + goto out; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + fscrypt_free_filename(&fname); + goto out; + } + + /* + * We have two inodes to update in the log, the old directory and + * the inode that got renamed, so we must pin the log to prevent + * anyone from syncing the log until we have updated both inodes + * in the log. + */ + ret = join_running_log_trans(root); + /* + * At least one of the inodes was logged before, so this should + * not fail, but if it does, it's not serious, just bail out and + * mark the log for a full commit. + */ + if (WARN_ON_ONCE(ret < 0)) { + btrfs_free_path(path); + fscrypt_free_filename(&fname); + goto out; + } + + log_pinned = true; + + /* + * Other concurrent task might be logging the old directory, + * as it can be triggered when logging other inode that had or + * still has a dentry in the old directory. We lock the old + * directory's log_mutex to ensure the deletion of the old + * name is persisted, because during directory logging we + * delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of + * the old name's dir index item is in the delayed items, so + * it could be missed by an in progress directory logging. + */ + mutex_lock(&old_dir->log_mutex); + ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir), + &fname.disk_name, old_dir_index); + if (ret > 0) { + /* + * The dentry does not exist in the log, so record its + * deletion. + */ + btrfs_release_path(path); + ret = insert_dir_log_key(trans, log, path, + btrfs_ino(old_dir), + old_dir_index, old_dir_index); + } + mutex_unlock(&old_dir->log_mutex); + + btrfs_free_path(path); + fscrypt_free_filename(&fname); + if (ret < 0) + goto out; + } + + /* + * We don't care about the return value. If we fail to log the new name + * then we know the next attempt to sync the log will fallback to a full + * transaction commit (due to a call to btrfs_set_log_full_commit()), so + * we don't need to worry about getting a log committed that has an + * inconsistent state after a rename operation. + */ + btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx); + ASSERT(list_empty(&ctx.conflict_inodes)); +out: + trace_btrfs_log_new_name_exit(trans, inode, old_dir, ret); + /* + * If an error happened mark the log for a full commit because it's not + * consistent and up to date or we couldn't find out if one of the + * inodes was logged before in this transaction. Do it before unpinning + * the log, to avoid any races with someone else trying to commit it. + */ + if (ret < 0) + btrfs_set_log_full_commit(trans); + if (log_pinned) + btrfs_end_log_trans(root); + free_extent_buffer(ctx.scratch_eb); +} + |