From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/exfat/inode.c | 459 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 459 insertions(+) create mode 100644 fs/exfat/inode.c (limited to 'fs/exfat/inode.c') diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c new file mode 100644 index 000000000..ccd136301 --- /dev/null +++ b/fs/exfat/inode.c @@ -0,0 +1,459 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "exfat_raw.h" +#include "exfat_fs.h" +#include "iomap.h" + +int __exfat_write_inode(struct inode *inode, int sync) +{ + unsigned long long on_disk_size; + unsigned long long on_disk_valid_size; + struct exfat_dentry *ep, *ep2; + struct exfat_entry_set_cache es; + struct super_block *sb = inode->i_sb; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_inode_info *ei = EXFAT_I(inode); + bool is_dir = (ei->type == TYPE_DIR); + struct timespec64 ts; + + if (inode->i_ino == EXFAT_ROOT_INO) + return 0; + + /* + * If the inode is already unlinked, there is no need for updating it. + */ + if (ei->dir.dir == DIR_DELETED) + return 0; + + if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1) + return 0; + + exfat_set_volume_dirty(sb); + + /* get the directory entry of given file or directory */ + if (exfat_get_dentry_set_by_ei(&es, sb, ei)) + return -EIO; + ep = exfat_get_dentry_cached(&es, ES_IDX_FILE); + ep2 = exfat_get_dentry_cached(&es, ES_IDX_STREAM); + + ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode)); + + /* set FILE_INFO structure using the acquired struct exfat_dentry */ + exfat_set_entry_time(sbi, &ei->i_crtime, + &ep->dentry.file.create_tz, + &ep->dentry.file.create_time, + &ep->dentry.file.create_date, + &ep->dentry.file.create_time_cs); + ts = inode_get_mtime(inode); + exfat_set_entry_time(sbi, &ts, + &ep->dentry.file.modify_tz, + &ep->dentry.file.modify_time, + &ep->dentry.file.modify_date, + &ep->dentry.file.modify_time_cs); + ts = inode_get_atime(inode); + exfat_set_entry_time(sbi, &ts, + &ep->dentry.file.access_tz, + &ep->dentry.file.access_time, + &ep->dentry.file.access_date, + NULL); + + /* + * During a DIO write, valid_size is updated eagerly in iomap_end (so + * that concurrent buffered reads see IOMAP_MAPPED) while i_size is + * updated asynchronously in end_io. The FAT chain was already + * extended to cover ceil(valid_size/cluster_size) clusters. Use the + * maximum so the on-disk size field always covers the FAT chain, + * preventing fsck from reporting "more clusters are allocated". + */ + on_disk_size = max_t(unsigned long long, i_size_read(inode), + ei->valid_size); + + if (ei->start_clu == EXFAT_EOF_CLUSTER) + on_disk_size = 0; + /* + * valid_size on disk must reflect only confirmed data (up to i_size) + * and must not exceed on_disk_size. + */ + on_disk_valid_size = min_t(unsigned long long, ei->valid_size, + i_size_read(inode)); + if (ei->start_clu == EXFAT_EOF_CLUSTER) + on_disk_valid_size = 0; + + ep2->dentry.stream.size = cpu_to_le64(on_disk_size); + ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_valid_size); + + if (on_disk_size) { + ep2->dentry.stream.flags = ei->flags; + ep2->dentry.stream.start_clu = cpu_to_le32(ei->start_clu); + } else { + ep2->dentry.stream.flags = ALLOC_FAT_CHAIN; + ep2->dentry.stream.start_clu = EXFAT_FREE_CLUSTER; + } + + exfat_update_dir_chksum(&es); + return exfat_put_dentry_set(&es, sync); +} + +int exfat_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + int ret; + + if (unlikely(exfat_forced_shutdown(inode->i_sb))) + return -EIO; + + mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); + ret = __exfat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL); + mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); + + return ret; +} + +void exfat_sync_inode(struct inode *inode) +{ + lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock); + __exfat_write_inode(inode, 1); +} + +/* + * Input: inode, (logical) clu_offset, target allocation area + * Output: errcode, cluster number + * *clu = (~0), if it's unable to allocate a new cluster + */ +int exfat_map_cluster(struct inode *inode, unsigned int clu_offset, + unsigned int *clu, unsigned int *count, int create, + bool *balloc) +{ + int ret; + unsigned int last_clu; + struct exfat_chain new_clu; + struct super_block *sb = inode->i_sb; + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_inode_info *ei = EXFAT_I(inode); + unsigned int local_clu_offset = clu_offset; + unsigned int num_to_be_allocated = 0, num_clusters; + + num_clusters = exfat_bytes_to_cluster(sbi, exfat_ondisk_size(inode)); + if (clu_offset > num_clusters || + *count > num_clusters - clu_offset) + num_to_be_allocated = clu_offset + *count - num_clusters; + + if (!create && (num_to_be_allocated > 0)) { + *clu = EXFAT_EOF_CLUSTER; + return 0; + } + + *clu = last_clu = ei->start_clu; + + if (*clu == EXFAT_EOF_CLUSTER) { + *count = 0; + } else if (ei->flags == ALLOC_NO_FAT_CHAIN) { + last_clu += num_clusters - 1; + if (clu_offset < num_clusters) { + *clu += clu_offset; + *count = min(num_clusters - clu_offset, *count); + } else { + *clu = EXFAT_EOF_CLUSTER; + *count = 0; + } + } else { + int err = exfat_get_cluster(inode, clu_offset, + clu, count, &last_clu); + if (err) + return -EIO; + } + + if (*clu == EXFAT_EOF_CLUSTER) { + exfat_set_volume_dirty(sb); + + new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ? + EXFAT_EOF_CLUSTER : last_clu + 1; + new_clu.size = 0; + new_clu.flags = ei->flags; + + /* allocate a cluster */ + if (num_to_be_allocated < 1) { + /* Broken FAT (i_sze > allocated FAT) */ + exfat_fs_error(sb, "broken FAT chain."); + return -EIO; + } + + ret = exfat_alloc_cluster(inode, num_to_be_allocated, &new_clu, + inode_needs_sync(inode), true); + if (ret) + return ret; + + if (new_clu.dir == EXFAT_EOF_CLUSTER || + new_clu.dir == EXFAT_FREE_CLUSTER) { + exfat_fs_error(sb, + "bogus cluster new allocated (last_clu : %u, new_clu : %u)", + last_clu, new_clu.dir); + return -EIO; + } + + /* append to the FAT chain */ + if (last_clu == EXFAT_EOF_CLUSTER) { + if (new_clu.flags == ALLOC_FAT_CHAIN) + ei->flags = ALLOC_FAT_CHAIN; + ei->start_clu = new_clu.dir; + } else { + if (new_clu.flags != ei->flags) { + /* no-fat-chain bit is disabled, + * so fat-chain should be synced with + * alloc-bitmap + */ + if (exfat_chain_cont_cluster(sb, ei->start_clu, + num_clusters)) + return -EIO; + ei->flags = ALLOC_FAT_CHAIN; + } + if (new_clu.flags == ALLOC_FAT_CHAIN) + if (exfat_ent_set(sb, last_clu, new_clu.dir)) + return -EIO; + } + + *clu = new_clu.dir; + *count = new_clu.size; + + inode->i_blocks += exfat_cluster_to_sectors(sbi, new_clu.size); + if (balloc) + *balloc = true; + } + + /* hint information */ + ei->hint_bmap.off = local_clu_offset; + ei->hint_bmap.clu = *clu; + + return 0; +} + +static int exfat_read_folio(struct file *file, struct folio *folio) +{ + struct iomap_read_folio_ctx ctx = { + .cur_folio = folio, + .ops = &exfat_iomap_bio_read_ops, + }; + + iomap_read_folio(&exfat_iomap_ops, &ctx, NULL); + return 0; +} + +static void exfat_readahead(struct readahead_control *rac) +{ + struct address_space *mapping = rac->mapping; + struct inode *inode = mapping->host; + struct exfat_inode_info *ei = EXFAT_I(inode); + loff_t pos = readahead_pos(rac); + struct iomap_read_folio_ctx ctx = { + .ops = &exfat_iomap_bio_read_ops, + .rac = rac, + }; + + /* Range cross valid_size, read it page by page. */ + if (ei->valid_size < i_size_read(inode) && + pos <= ei->valid_size && + ei->valid_size < pos + readahead_length(rac)) + return; + + iomap_readahead(&exfat_iomap_ops, &ctx, NULL); +} + +static int exfat_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct iomap_writepage_ctx wpc = { + .inode = mapping->host, + .wbc = wbc, + .ops = &exfat_writeback_ops, + }; + + if (unlikely(exfat_forced_shutdown(mapping->host->i_sb))) + return -EIO; + + return iomap_writepages(&wpc); +} + +static sector_t exfat_aop_bmap(struct address_space *mapping, sector_t block) +{ + sector_t blocknr; + + inode_lock_shared(mapping->host); + blocknr = iomap_bmap(mapping, block, &exfat_iomap_ops); + inode_unlock_shared(mapping->host); + return blocknr; +} + +static const struct address_space_operations exfat_aops = { + .read_folio = exfat_read_folio, + .readahead = exfat_readahead, + .writepages = exfat_writepages, + .dirty_folio = iomap_dirty_folio, + .bmap = exfat_aop_bmap, + .migrate_folio = filemap_migrate_folio, + .is_partially_uptodate = iomap_is_partially_uptodate, + .error_remove_folio = generic_error_remove_folio, + .release_folio = iomap_release_folio, + .invalidate_folio = iomap_invalidate_folio, + .swap_activate = exfat_iomap_swap_activate, +}; + +static inline unsigned long exfat_hash(loff_t i_pos) +{ + return hash_32(i_pos, EXFAT_HASH_BITS); +} + +void exfat_hash_inode(struct inode *inode, loff_t i_pos) +{ + struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); + struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); + + spin_lock(&sbi->inode_hash_lock); + EXFAT_I(inode)->i_pos = i_pos; + hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head); + spin_unlock(&sbi->inode_hash_lock); +} + +void exfat_unhash_inode(struct inode *inode) +{ + struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); + + spin_lock(&sbi->inode_hash_lock); + hlist_del_init(&EXFAT_I(inode)->i_hash_fat); + EXFAT_I(inode)->i_pos = 0; + spin_unlock(&sbi->inode_hash_lock); +} + +struct inode *exfat_iget(struct super_block *sb, loff_t i_pos) +{ + struct exfat_sb_info *sbi = EXFAT_SB(sb); + struct exfat_inode_info *info; + struct hlist_head *head = sbi->inode_hashtable + exfat_hash(i_pos); + struct inode *inode = NULL; + + spin_lock(&sbi->inode_hash_lock); + hlist_for_each_entry(info, head, i_hash_fat) { + WARN_ON(info->vfs_inode.i_sb != sb); + + if (i_pos != info->i_pos) + continue; + inode = igrab(&info->vfs_inode); + if (inode) + break; + } + spin_unlock(&sbi->inode_hash_lock); + return inode; +} + +/* doesn't deal with root inode */ +static int exfat_fill_inode(struct inode *inode, struct exfat_dir_entry *info) +{ + struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb); + struct exfat_inode_info *ei = EXFAT_I(inode); + loff_t size = info->size; + + ei->dir = info->dir; + ei->entry = info->entry; + ei->attr = info->attr; + ei->start_clu = info->start_clu; + ei->flags = info->flags; + ei->type = info->type; + ei->valid_size = info->valid_size; + ei->zeroed_size = info->valid_size; + + ei->version = 0; + ei->hint_stat.eidx = 0; + ei->hint_stat.clu = info->start_clu; + ei->hint_femp.eidx = EXFAT_HINT_NONE; + ei->hint_bmap.off = EXFAT_EOF_CLUSTER; + ei->i_pos = 0; + + inode->i_uid = sbi->options.fs_uid; + inode->i_gid = sbi->options.fs_gid; + inode_inc_iversion(inode); + inode->i_generation = get_random_u32(); + + if (info->attr & EXFAT_ATTR_SUBDIR) { /* directory */ + inode->i_generation &= ~1; + inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); + inode->i_op = &exfat_dir_inode_operations; + inode->i_fop = &exfat_dir_operations; + set_nlink(inode, info->num_subdirs); + } else { /* regular file */ + inode->i_generation |= 1; + inode->i_mode = exfat_make_mode(sbi, info->attr, 0777); + inode->i_op = &exfat_file_inode_operations; + inode->i_fop = &exfat_file_operations; + inode->i_mapping->a_ops = &exfat_aops; + inode->i_mapping->nrpages = 0; + } + + i_size_write(inode, size); + + exfat_save_attr(inode, info->attr); + + inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9; + inode_set_mtime_to_ts(inode, info->mtime); + inode_set_ctime_to_ts(inode, info->mtime); + ei->i_crtime = info->crtime; + inode_set_atime_to_ts(inode, info->atime); + + return 0; +} + +struct inode *exfat_build_inode(struct super_block *sb, + struct exfat_dir_entry *info, loff_t i_pos) +{ + struct inode *inode; + int err; + + inode = exfat_iget(sb, i_pos); + if (inode) + goto out; + inode = new_inode(sb); + if (!inode) { + inode = ERR_PTR(-ENOMEM); + goto out; + } + inode->i_ino = iunique(sb, EXFAT_ROOT_INO); + inode_set_iversion(inode, 1); + err = exfat_fill_inode(inode, info); + if (err) { + iput(inode); + inode = ERR_PTR(err); + goto out; + } + exfat_hash_inode(inode, i_pos); + insert_inode_hash(inode); +out: + return inode; +} + +void exfat_evict_inode(struct inode *inode) +{ + truncate_inode_pages_final(&inode->i_data); + + if (!inode->i_nlink) { + i_size_write(inode, 0); + mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock); + __exfat_truncate(inode); + mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock); + } + + clear_inode(inode); + exfat_cache_inval_inode(inode); + exfat_unhash_inode(inode); +} -- cgit v1.3.1