From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- fs/ubifs/tnc_commit.c | 1112 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1112 insertions(+) create mode 100644 fs/ubifs/tnc_commit.c (limited to 'fs/ubifs/tnc_commit.c') diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c new file mode 100644 index 000000000..7bf267206 --- /dev/null +++ b/fs/ubifs/tnc_commit.c @@ -0,0 +1,1112 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* This file implements TNC functions for committing */ + +#include +#include "ubifs.h" + +/** + * make_idx_node - make an index node for fill-the-gaps method of TNC commit. + * @c: UBIFS file-system description object + * @idx: buffer in which to place new index node + * @znode: znode from which to make new index node + * @lnum: LEB number where new index node will be written + * @offs: offset where new index node will be written + * @len: length of new index node + */ +static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx, + struct ubifs_znode *znode, int lnum, int offs, int len) +{ + struct ubifs_znode *zp; + u8 hash[UBIFS_HASH_ARR_SZ]; + int i, err; + + /* Make index node */ + idx->ch.node_type = UBIFS_IDX_NODE; + idx->child_cnt = cpu_to_le16(znode->child_cnt); + idx->level = cpu_to_le16(znode->level); + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + key_write_idx(c, &zbr->key, &br->key); + br->lnum = cpu_to_le32(zbr->lnum); + br->offs = cpu_to_le32(zbr->offs); + br->len = cpu_to_le32(zbr->len); + ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br)); + if (!zbr->lnum || !zbr->len) { + ubifs_err(c, "bad ref in znode"); + ubifs_dump_znode(c, znode); + if (zbr->znode) + ubifs_dump_znode(c, zbr->znode); + + return -EINVAL; + } + } + ubifs_prepare_node(c, idx, len, 0); + ubifs_node_calc_hash(c, idx, hash); + + znode->lnum = lnum; + znode->offs = offs; + znode->len = len; + + err = insert_old_idx_znode(c, znode); + + /* Update the parent */ + zp = znode->parent; + if (zp) { + struct ubifs_zbranch *zbr; + + zbr = &zp->zbranch[znode->iip]; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + ubifs_copy_hash(c, hash, zbr->hash); + } else { + c->zroot.lnum = lnum; + c->zroot.offs = offs; + c->zroot.len = len; + ubifs_copy_hash(c, hash, c->zroot.hash); + } + c->calc_idx_sz += ALIGN(len, 8); + + atomic_long_dec(&c->dirty_zn_cnt); + + ubifs_assert(c, ubifs_zn_dirty(znode)); + ubifs_assert(c, ubifs_zn_cow(znode)); + + /* + * Note, unlike 'write_index()' we do not add memory barriers here + * because this function is called with @c->tnc_mutex locked. + */ + __clear_bit(DIRTY_ZNODE, &znode->flags); + __clear_bit(COW_ZNODE, &znode->flags); + + return err; +} + +/** + * fill_gap - make index nodes in gaps in dirty index LEBs. + * @c: UBIFS file-system description object + * @lnum: LEB number that gap appears in + * @gap_start: offset of start of gap + * @gap_end: offset of end of gap + * @dirt: adds dirty space to this + * + * This function returns the number of index nodes written into the gap. + */ +static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end, + int *dirt) +{ + int len, gap_remains, gap_pos, written, pad_len; + + ubifs_assert(c, (gap_start & 7) == 0); + ubifs_assert(c, (gap_end & 7) == 0); + ubifs_assert(c, gap_end >= gap_start); + + gap_remains = gap_end - gap_start; + if (!gap_remains) + return 0; + gap_pos = gap_start; + written = 0; + while (c->enext) { + len = ubifs_idx_node_sz(c, c->enext->child_cnt); + if (len < gap_remains) { + struct ubifs_znode *znode = c->enext; + const int alen = ALIGN(len, 8); + int err; + + ubifs_assert(c, alen <= gap_remains); + err = make_idx_node(c, c->ileb_buf + gap_pos, znode, + lnum, gap_pos, len); + if (err) + return err; + gap_remains -= alen; + gap_pos += alen; + c->enext = znode->cnext; + if (c->enext == c->cnext) + c->enext = NULL; + written += 1; + } else + break; + } + if (gap_end == c->leb_size) { + c->ileb_len = ALIGN(gap_pos, c->min_io_size); + /* Pad to end of min_io_size */ + pad_len = c->ileb_len - gap_pos; + } else + /* Pad to end of gap */ + pad_len = gap_remains; + dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d", + lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len); + ubifs_pad(c, c->ileb_buf + gap_pos, pad_len); + *dirt += pad_len; + return written; +} + +/** + * find_old_idx - find an index node obsoleted since the last commit start. + * @c: UBIFS file-system description object + * @lnum: LEB number of obsoleted index node + * @offs: offset of obsoleted index node + * + * Returns %1 if found and %0 otherwise. + */ +static int find_old_idx(struct ubifs_info *c, int lnum, int offs) +{ + struct ubifs_old_idx *o; + struct rb_node *p; + + p = c->old_idx.rb_node; + while (p) { + o = rb_entry(p, struct ubifs_old_idx, rb); + if (lnum < o->lnum) + p = p->rb_left; + else if (lnum > o->lnum) + p = p->rb_right; + else if (offs < o->offs) + p = p->rb_left; + else if (offs > o->offs) + p = p->rb_right; + else + return 1; + } + return 0; +} + +/** + * is_idx_node_in_use - determine if an index node can be overwritten. + * @c: UBIFS file-system description object + * @key: key of index node + * @level: index node level + * @lnum: LEB number of index node + * @offs: offset of index node + * + * If @key / @lnum / @offs identify an index node that was not part of the old + * index, then this function returns %0 (obsolete). Else if the index node was + * part of the old index but is now dirty %1 is returned, else if it is clean %2 + * is returned. A negative error code is returned on failure. + */ +static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key, + int level, int lnum, int offs) +{ + int ret; + + ret = is_idx_node_in_tnc(c, key, level, lnum, offs); + if (ret < 0) + return ret; /* Error code */ + if (ret == 0) + if (find_old_idx(c, lnum, offs)) + return 1; + return ret; +} + +/** + * layout_leb_in_gaps - layout index nodes using in-the-gaps method. + * @c: UBIFS file-system description object + * @p: return LEB number in @c->gap_lebs[p] + * + * This function lays out new index nodes for dirty znodes using in-the-gaps + * method of TNC commit. + * This function merely puts the next znode into the next gap, making no attempt + * to try to maximise the number of znodes that fit. + * This function returns the number of index nodes written into the gaps, or a + * negative error code on failure. + */ +static int layout_leb_in_gaps(struct ubifs_info *c, int p) +{ + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written; + + tot_written = 0; + /* Get an index LEB with lots of obsolete index nodes */ + lnum = ubifs_find_dirty_idx_leb(c); + if (lnum < 0) + /* + * There also may be dirt in the index head that could be + * filled, however we do not check there at present. + */ + return lnum; /* Error code */ + c->gap_lebs[p] = lnum; + dbg_gc("LEB %d", lnum); + /* + * Scan the index LEB. We use the generic scan for this even though + * it is more comprehensive and less efficient than is needed for this + * purpose. + */ + sleb = ubifs_scan(c, lnum, 0, c->ileb_buf, 0); + c->ileb_len = 0; + if (IS_ERR(sleb)) + return PTR_ERR(sleb); + gap_start = 0; + list_for_each_entry(snod, &sleb->nodes, list) { + struct ubifs_idx_node *idx; + int in_use, level; + + ubifs_assert(c, snod->type == UBIFS_IDX_NODE); + idx = snod->node; + key_read(c, ubifs_idx_key(c, idx), &snod->key); + level = le16_to_cpu(idx->level); + /* Determine if the index node is in use (not obsolete) */ + in_use = is_idx_node_in_use(c, &snod->key, level, lnum, + snod->offs); + if (in_use < 0) { + ubifs_scan_destroy(sleb); + return in_use; /* Error code */ + } + if (in_use) { + if (in_use == 1) + dirt += ALIGN(snod->len, 8); + /* + * The obsolete index nodes form gaps that can be + * overwritten. This gap has ended because we have + * found an index node that is still in use + * i.e. not obsolete + */ + gap_end = snod->offs; + /* Try to fill gap */ + written = fill_gap(c, lnum, gap_start, gap_end, &dirt); + if (written < 0) { + ubifs_scan_destroy(sleb); + return written; /* Error code */ + } + tot_written += written; + gap_start = ALIGN(snod->offs + snod->len, 8); + } + } + ubifs_scan_destroy(sleb); + c->ileb_len = c->leb_size; + gap_end = c->leb_size; + /* Try to fill gap */ + written = fill_gap(c, lnum, gap_start, gap_end, &dirt); + if (written < 0) + return written; /* Error code */ + tot_written += written; + if (tot_written == 0) { + struct ubifs_lprops lp; + + dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); + err = ubifs_read_one_lp(c, lnum, &lp); + if (err) + return err; + if (lp.free == c->leb_size) { + /* + * We must have snatched this LEB from the idx_gc list + * so we need to correct the free and dirty space. + */ + err = ubifs_change_one_lp(c, lnum, + c->leb_size - c->ileb_len, + dirt, 0, 0, 0); + if (err) + return err; + } + return 0; + } + err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt, + 0, 0, 0); + if (err) + return err; + err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len); + if (err) + return err; + dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); + return tot_written; +} + +/** + * get_leb_cnt - calculate the number of empty LEBs needed to commit. + * @c: UBIFS file-system description object + * @cnt: number of znodes to commit + * + * This function returns the number of empty LEBs needed to commit @cnt znodes + * to the current index head. The number is not exact and may be more than + * needed. + */ +static int get_leb_cnt(struct ubifs_info *c, int cnt) +{ + int d; + + /* Assume maximum index node size (i.e. overestimate space needed) */ + cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz; + if (cnt < 0) + cnt = 0; + d = c->leb_size / c->max_idx_node_sz; + return DIV_ROUND_UP(cnt, d); +} + +/** + * layout_in_gaps - in-the-gaps method of committing TNC. + * @c: UBIFS file-system description object + * @cnt: number of dirty znodes to commit. + * + * This function lays out new index nodes for dirty znodes using in-the-gaps + * method of TNC commit. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_in_gaps(struct ubifs_info *c, int cnt) +{ + int err, leb_needed_cnt, written, p = 0, old_idx_lebs, *gap_lebs; + + dbg_gc("%d znodes to write", cnt); + + c->gap_lebs = kmalloc_objs(int, c->lst.idx_lebs + 1, GFP_NOFS); + if (!c->gap_lebs) + return -ENOMEM; + + old_idx_lebs = c->lst.idx_lebs; + do { + ubifs_assert(c, p < c->lst.idx_lebs); + written = layout_leb_in_gaps(c, p); + if (written < 0) { + err = written; + if (err != -ENOSPC) { + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return err; + } + if (!dbg_is_chk_index(c)) { + /* + * Do not print scary warnings if the debugging + * option which forces in-the-gaps is enabled. + */ + ubifs_warn(c, "out of space"); + ubifs_dump_budg(c, &c->bi); + ubifs_dump_lprops(c); + } + /* Try to commit anyway */ + break; + } + p++; + cnt -= written; + leb_needed_cnt = get_leb_cnt(c, cnt); + dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt, + leb_needed_cnt, c->ileb_cnt); + /* + * Dynamically change the size of @c->gap_lebs to prevent + * oob, because @c->lst.idx_lebs could be increased by + * function @get_idx_gc_leb (called by layout_leb_in_gaps-> + * ubifs_find_dirty_idx_leb) during loop. Only enlarge + * @c->gap_lebs when needed. + * + */ + if (leb_needed_cnt > c->ileb_cnt && p >= old_idx_lebs && + old_idx_lebs < c->lst.idx_lebs) { + old_idx_lebs = c->lst.idx_lebs; + gap_lebs = krealloc(c->gap_lebs, sizeof(int) * + (old_idx_lebs + 1), GFP_NOFS); + if (!gap_lebs) { + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return -ENOMEM; + } + c->gap_lebs = gap_lebs; + } + } while (leb_needed_cnt > c->ileb_cnt); + + c->gap_lebs[p] = -1; + return 0; +} + +/** + * layout_in_empty_space - layout index nodes in empty space. + * @c: UBIFS file-system description object + * + * This function lays out new index nodes for dirty znodes using empty LEBs. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_in_empty_space(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext, *zp; + int lnum, offs, len, next_len, buf_len, buf_offs, used, avail; + int wlen, blen, err; + + cnext = c->enext; + if (!cnext) + return 0; + + lnum = c->ihead_lnum; + buf_offs = c->ihead_offs; + + buf_len = ubifs_idx_node_sz(c, c->fanout); + buf_len = ALIGN(buf_len, c->min_io_size); + used = 0; + avail = buf_len; + + /* Ensure there is enough room for first write */ + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + if (buf_offs + next_len > c->leb_size) + lnum = -1; + + while (1) { + znode = cnext; + + len = ubifs_idx_node_sz(c, znode->child_cnt); + + /* Determine the index node position */ + if (lnum == -1) { + if (c->ileb_nxt >= c->ileb_cnt) { + ubifs_err(c, "out of space"); + return -ENOSPC; + } + lnum = c->ilebs[c->ileb_nxt++]; + buf_offs = 0; + used = 0; + avail = buf_len; + } + + offs = buf_offs + used; + + znode->lnum = lnum; + znode->offs = offs; + znode->len = len; + + /* Update the parent */ + zp = znode->parent; + if (zp) { + struct ubifs_zbranch *zbr; + int i; + + i = znode->iip; + zbr = &zp->zbranch[i]; + zbr->lnum = lnum; + zbr->offs = offs; + zbr->len = len; + } else { + c->zroot.lnum = lnum; + c->zroot.offs = offs; + c->zroot.len = len; + } + c->calc_idx_sz += ALIGN(len, 8); + + /* + * Once lprops is updated, we can decrease the dirty znode count + * but it is easier to just do it here. + */ + atomic_long_dec(&c->dirty_zn_cnt); + + /* + * Calculate the next index node length to see if there is + * enough room for it + */ + cnext = znode->cnext; + if (cnext == c->cnext) + next_len = 0; + else + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + + /* Update buffer positions */ + wlen = used + len; + used += ALIGN(len, 8); + avail -= ALIGN(len, 8); + + if (next_len != 0 && + buf_offs + used + next_len <= c->leb_size && + avail > 0) + continue; + + if (avail <= 0 && next_len && + buf_offs + used + next_len <= c->leb_size) + blen = buf_len; + else + blen = ALIGN(wlen, c->min_io_size); + + /* The buffer is full or there are no more znodes to do */ + buf_offs += blen; + if (next_len) { + if (buf_offs + next_len > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, + c->leb_size - buf_offs, blen - used, + 0, 0); + if (err) + return err; + lnum = -1; + } + used -= blen; + if (used < 0) + used = 0; + avail = buf_len - used; + continue; + } + err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs, + blen - used, 0, 0); + if (err) + return err; + break; + } + + c->dbg->new_ihead_lnum = lnum; + c->dbg->new_ihead_offs = buf_offs; + + return 0; +} + +/** + * layout_commit - determine positions of index nodes to commit. + * @c: UBIFS file-system description object + * @no_space: indicates that insufficient empty LEBs were allocated + * @cnt: number of znodes to commit + * + * Calculate and update the positions of index nodes to commit. If there were + * an insufficient number of empty LEBs allocated, then index nodes are placed + * into the gaps created by obsolete index nodes in non-empty index LEBs. For + * this purpose, an obsolete index node is one that was not in the index as at + * the end of the last commit. To write "in-the-gaps" requires that those index + * LEBs are updated atomically in-place. + */ +static int layout_commit(struct ubifs_info *c, int no_space, int cnt) +{ + int err; + + if (no_space) { + err = layout_in_gaps(c, cnt); + if (err) + return err; + } + err = layout_in_empty_space(c); + return err; +} + +/** + * find_first_dirty - find first dirty znode. + * @znode: znode to begin searching from + */ +static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode) +{ + int i, cont; + + if (!znode) + return NULL; + + while (1) { + if (znode->level == 0) { + if (ubifs_zn_dirty(znode)) + return znode; + return NULL; + } + cont = 0; + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + if (zbr->znode && ubifs_zn_dirty(zbr->znode)) { + znode = zbr->znode; + cont = 1; + break; + } + } + if (!cont) { + if (ubifs_zn_dirty(znode)) + return znode; + return NULL; + } + } +} + +/** + * find_next_dirty - find next dirty znode. + * @znode: znode to begin searching from + */ +static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode) +{ + int n = znode->iip + 1; + + znode = znode->parent; + if (!znode) + return NULL; + for (; n < znode->child_cnt; n++) { + struct ubifs_zbranch *zbr = &znode->zbranch[n]; + + if (zbr->znode && ubifs_zn_dirty(zbr->znode)) + return find_first_dirty(zbr->znode); + } + return znode; +} + +/** + * get_znodes_to_commit - create list of dirty znodes to commit. + * @c: UBIFS file-system description object + * + * This function returns the number of znodes to commit. + */ +static int get_znodes_to_commit(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext; + int cnt = 0; + + c->cnext = find_first_dirty(c->zroot.znode); + znode = c->enext = c->cnext; + if (!znode) { + dbg_cmt("no znodes to commit"); + return 0; + } + cnt += 1; + while (1) { + ubifs_assert(c, !ubifs_zn_cow(znode)); + __set_bit(COW_ZNODE, &znode->flags); + znode->alt = 0; + cnext = find_next_dirty(znode); + if (!cnext) { + ubifs_assert(c, !znode->parent); + znode->cparent = NULL; + znode->cnext = c->cnext; + break; + } + znode->cparent = znode->parent; + znode->ciip = znode->iip; + znode->cnext = cnext; + znode = cnext; + cnt += 1; + } + dbg_cmt("committing %d znodes", cnt); + ubifs_assert(c, cnt == atomic_long_read(&c->dirty_zn_cnt)); + return cnt; +} + +/** + * alloc_idx_lebs - allocate empty LEBs to be used to commit. + * @c: UBIFS file-system description object + * @cnt: number of znodes to commit + * + * This function returns %-ENOSPC if it cannot allocate a sufficient number of + * empty LEBs. %0 is returned on success, otherwise a negative error code + * is returned. + */ +static int alloc_idx_lebs(struct ubifs_info *c, int cnt) +{ + int i, leb_cnt, lnum; + + c->ileb_cnt = 0; + c->ileb_nxt = 0; + leb_cnt = get_leb_cnt(c, cnt); + dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt); + if (!leb_cnt) + return 0; + c->ilebs = kmalloc_objs(int, leb_cnt, GFP_NOFS); + if (!c->ilebs) + return -ENOMEM; + for (i = 0; i < leb_cnt; i++) { + lnum = ubifs_find_free_leb_for_idx(c); + if (lnum < 0) + return lnum; + c->ilebs[c->ileb_cnt++] = lnum; + dbg_cmt("LEB %d", lnum); + } + if (dbg_is_chk_index(c) && !get_random_u32_below(8)) + return -ENOSPC; + return 0; +} + +/** + * free_unused_idx_lebs - free unused LEBs that were allocated for the commit. + * @c: UBIFS file-system description object + * + * It is possible that we allocate more empty LEBs for the commit than we need. + * This functions frees the surplus. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int free_unused_idx_lebs(struct ubifs_info *c) +{ + int i, err = 0, lnum, er; + + for (i = c->ileb_nxt; i < c->ileb_cnt; i++) { + lnum = c->ilebs[i]; + dbg_cmt("LEB %d", lnum); + er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_INDEX | LPROPS_TAKEN, 0); + if (!err) + err = er; + } + return err; +} + +/** + * free_idx_lebs - free unused LEBs after commit end. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int free_idx_lebs(struct ubifs_info *c) +{ + int err; + + err = free_unused_idx_lebs(c); + kfree(c->ilebs); + c->ilebs = NULL; + return err; +} + +/** + * ubifs_tnc_start_commit - start TNC commit. + * @c: UBIFS file-system description object + * @zroot: new index root position is returned here + * + * This function prepares the list of indexing nodes to commit and lays out + * their positions on flash. If there is not enough free space it uses the + * in-gap commit method. Returns zero in case of success and a negative error + * code in case of failure. + */ +int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot) +{ + int err = 0, cnt; + + mutex_lock(&c->tnc_mutex); + err = dbg_check_tnc(c, 1); + if (err) + goto out; + cnt = get_znodes_to_commit(c); + if (cnt != 0) { + int no_space = 0; + + err = alloc_idx_lebs(c, cnt); + if (err == -ENOSPC) + no_space = 1; + else if (err) + goto out_free; + err = layout_commit(c, no_space, cnt); + if (err) + goto out_free; + ubifs_assert(c, atomic_long_read(&c->dirty_zn_cnt) == 0); + err = free_unused_idx_lebs(c); + if (err) + goto out; + } + destroy_old_idx(c); + memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch)); + + err = ubifs_save_dirty_idx_lnums(c); + if (err) + goto out; + + spin_lock(&c->space_lock); + /* + * Although we have not finished committing yet, update size of the + * committed index ('c->bi.old_idx_sz') and zero out the index growth + * budget. It is OK to do this now, because we've reserved all the + * space which is needed to commit the index, and it is save for the + * budgeting subsystem to assume the index is already committed, + * even though it is not. + */ + ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c)); + c->bi.old_idx_sz = c->calc_idx_sz; + c->bi.uncommitted_idx = 0; + c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); + spin_unlock(&c->space_lock); + mutex_unlock(&c->tnc_mutex); + + dbg_cmt("number of index LEBs %d", c->lst.idx_lebs); + dbg_cmt("size of index %llu", c->calc_idx_sz); + return err; + +out_free: + free_idx_lebs(c); +out: + mutex_unlock(&c->tnc_mutex); + return err; +} + +/** + * write_index - write index nodes. + * @c: UBIFS file-system description object + * + * This function writes the index nodes whose positions were laid out in the + * layout_in_empty_space function. + */ +static int write_index(struct ubifs_info *c) +{ + struct ubifs_idx_node *idx; + struct ubifs_znode *znode, *cnext; + int i, lnum, offs, len, next_len, buf_len, buf_offs, used; + int avail, wlen, err, lnum_pos = 0, blen, nxt_offs; + + cnext = c->enext; + if (!cnext) + return 0; + + /* + * Always write index nodes to the index head so that index nodes and + * other types of nodes are never mixed in the same erase block. + */ + lnum = c->ihead_lnum; + buf_offs = c->ihead_offs; + + /* Allocate commit buffer */ + buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size); + used = 0; + avail = buf_len; + + /* Ensure there is enough room for first write */ + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + if (buf_offs + next_len > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0, + LPROPS_TAKEN); + if (err) + return err; + lnum = -1; + } + + while (1) { + u8 hash[UBIFS_HASH_ARR_SZ]; + + cond_resched(); + + znode = cnext; + idx = c->cbuf + used; + + /* Make index node */ + idx->ch.node_type = UBIFS_IDX_NODE; + idx->child_cnt = cpu_to_le16(znode->child_cnt); + idx->level = cpu_to_le16(znode->level); + for (i = 0; i < znode->child_cnt; i++) { + struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); + struct ubifs_zbranch *zbr = &znode->zbranch[i]; + + key_write_idx(c, &zbr->key, &br->key); + br->lnum = cpu_to_le32(zbr->lnum); + br->offs = cpu_to_le32(zbr->offs); + br->len = cpu_to_le32(zbr->len); + ubifs_copy_hash(c, zbr->hash, ubifs_branch_hash(c, br)); + if (!zbr->lnum || !zbr->len) { + ubifs_err(c, "bad ref in znode"); + ubifs_dump_znode(c, znode); + if (zbr->znode) + ubifs_dump_znode(c, zbr->znode); + + return -EINVAL; + } + } + len = ubifs_idx_node_sz(c, znode->child_cnt); + ubifs_prepare_node(c, idx, len, 0); + ubifs_node_calc_hash(c, idx, hash); + + mutex_lock(&c->tnc_mutex); + + if (znode->cparent) + ubifs_copy_hash(c, hash, + znode->cparent->zbranch[znode->ciip].hash); + + if (znode->parent) { + if (!ubifs_zn_obsolete(znode)) + ubifs_copy_hash(c, hash, + znode->parent->zbranch[znode->iip].hash); + } else { + ubifs_copy_hash(c, hash, c->zroot.hash); + } + + mutex_unlock(&c->tnc_mutex); + + /* Determine the index node position */ + if (lnum == -1) { + lnum = c->ilebs[lnum_pos++]; + buf_offs = 0; + used = 0; + avail = buf_len; + } + offs = buf_offs + used; + + if (lnum != znode->lnum || offs != znode->offs || + len != znode->len) { + ubifs_err(c, "inconsistent znode posn"); + return -EINVAL; + } + + /* Grab some stuff from znode while we still can */ + cnext = znode->cnext; + + ubifs_assert(c, ubifs_zn_dirty(znode)); + ubifs_assert(c, ubifs_zn_cow(znode)); + + /* + * It is important that other threads should see %DIRTY_ZNODE + * flag cleared before %COW_ZNODE. Specifically, it matters in + * the 'dirty_cow_znode()' function. This is the reason for the + * first barrier. Also, we want the bit changes to be seen to + * other threads ASAP, to avoid unnecessary copying, which is + * the reason for the second barrier. + */ + clear_bit(DIRTY_ZNODE, &znode->flags); + smp_mb__before_atomic(); + clear_bit(COW_ZNODE, &znode->flags); + smp_mb__after_atomic(); + + /* + * We have marked the znode as clean but have not updated the + * @c->clean_zn_cnt counter. If this znode becomes dirty again + * before 'free_obsolete_znodes()' is called, then + * @c->clean_zn_cnt will be decremented before it gets + * incremented (resulting in 2 decrements for the same znode). + * This means that @c->clean_zn_cnt may become negative for a + * while. + * + * Q: why we cannot increment @c->clean_zn_cnt? + * A: because we do not have the @c->tnc_mutex locked, and the + * following code would be racy and buggy: + * + * if (!ubifs_zn_obsolete(znode)) { + * atomic_long_inc(&c->clean_zn_cnt); + * atomic_long_inc(&ubifs_clean_zn_cnt); + * } + * + * Thus, we just delay the @c->clean_zn_cnt update until we + * have the mutex locked. + */ + + /* Do not access znode from this point on */ + + /* Update buffer positions */ + wlen = used + len; + used += ALIGN(len, 8); + avail -= ALIGN(len, 8); + + /* + * Calculate the next index node length to see if there is + * enough room for it + */ + if (cnext == c->cnext) + next_len = 0; + else + next_len = ubifs_idx_node_sz(c, cnext->child_cnt); + + nxt_offs = buf_offs + used + next_len; + if (next_len && nxt_offs <= c->leb_size) { + if (avail > 0) + continue; + else + blen = buf_len; + } else { + wlen = ALIGN(wlen, 8); + blen = ALIGN(wlen, c->min_io_size); + ubifs_pad(c, c->cbuf + wlen, blen - wlen); + } + + /* The buffer is full or there are no more znodes to do */ + err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, blen); + if (err) + return err; + buf_offs += blen; + if (next_len) { + if (nxt_offs > c->leb_size) { + err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, + 0, LPROPS_TAKEN); + if (err) + return err; + lnum = -1; + } + used -= blen; + if (used < 0) + used = 0; + avail = buf_len - used; + memmove(c->cbuf, c->cbuf + blen, used); + continue; + } + break; + } + + if (lnum != c->dbg->new_ihead_lnum || + buf_offs != c->dbg->new_ihead_offs) { + ubifs_err(c, "inconsistent ihead"); + return -EINVAL; + } + + c->ihead_lnum = lnum; + c->ihead_offs = buf_offs; + + return 0; +} + +/** + * free_obsolete_znodes - free obsolete znodes. + * @c: UBIFS file-system description object + * + * At the end of commit end, obsolete znodes are freed. + */ +static void free_obsolete_znodes(struct ubifs_info *c) +{ + struct ubifs_znode *znode, *cnext; + + cnext = c->cnext; + do { + znode = cnext; + cnext = znode->cnext; + if (ubifs_zn_obsolete(znode)) + kfree(znode); + else { + znode->cnext = NULL; + atomic_long_inc(&c->clean_zn_cnt); + atomic_long_inc(&ubifs_clean_zn_cnt); + } + } while (cnext != c->cnext); +} + +/** + * return_gap_lebs - return LEBs used by the in-gap commit method. + * @c: UBIFS file-system description object + * + * This function clears the "taken" flag for the LEBs which were used by the + * "commit in-the-gaps" method. + */ +static int return_gap_lebs(struct ubifs_info *c) +{ + int *p, err; + + if (!c->gap_lebs) + return 0; + + dbg_cmt(""); + for (p = c->gap_lebs; *p != -1; p++) { + err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0, + LPROPS_TAKEN, 0); + if (err) + return err; + } + + kfree(c->gap_lebs); + c->gap_lebs = NULL; + return 0; +} + +/** + * ubifs_tnc_end_commit - update the TNC for commit end. + * @c: UBIFS file-system description object + * + * Write the dirty znodes. + */ +int ubifs_tnc_end_commit(struct ubifs_info *c) +{ + int err; + + if (!c->cnext) + return 0; + + err = return_gap_lebs(c); + if (err) + return err; + + err = write_index(c); + if (err) + return err; + + mutex_lock(&c->tnc_mutex); + + dbg_cmt("TNC height is %d", c->zroot.znode->level + 1); + + free_obsolete_znodes(c); + + c->cnext = NULL; + kfree(c->ilebs); + c->ilebs = NULL; + + mutex_unlock(&c->tnc_mutex); + + return 0; +} -- cgit v1.3.1