ext4: main fast-commit commit path
This patch adds main fast commit commit path handlers. The overall
patch can be divided into two inter-related parts:
(A) Metadata updates tracking
This part consists of helper functions to track changes that need
to be committed during a commit operation. These updates are
maintained by Ext4 in different in-memory queues. Following are
the APIs and their short description that are implemented in this
patch:
- ext4_fc_track_link/unlink/creat() - Track unlink. link and creat
operations
- ext4_fc_track_range() - Track changed logical block offsets
inodes
- ext4_fc_track_inode() - Track inodes
- ext4_fc_mark_ineligible() - Mark file system fast commit
ineligible()
- ext4_fc_start_update() / ext4_fc_stop_update() /
ext4_fc_start_ineligible() / ext4_fc_stop_ineligible() These
functions are useful for co-ordinating inode updates with
commits.
(B) Main commit Path
This part consists of functions to convert updates tracked in
in-memory data structures into on-disk commits. Function
ext4_fc_commit() is the main entry point to commit path.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-6-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index f2d11b4..79e947c 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -7,13 +7,1185 @@
*
* Ext4 fast commits routines.
*/
+#include "ext4.h"
#include "ext4_jbd2.h"
+#include "ext4_extents.h"
+#include "mballoc.h"
+
+/*
+ * Ext4 Fast Commits
+ * -----------------
+ *
+ * Ext4 fast commits implement fine grained journalling for Ext4.
+ *
+ * Fast commits are organized as a log of tag-length-value (TLV) structs. (See
+ * struct ext4_fc_tl). Each TLV contains some delta that is replayed TLV by
+ * TLV during the recovery phase. For the scenarios for which we currently
+ * don't have replay code, fast commit falls back to full commits.
+ * Fast commits record delta in one of the following three categories.
+ *
+ * (A) Directory entry updates:
+ *
+ * - EXT4_FC_TAG_UNLINK - records directory entry unlink
+ * - EXT4_FC_TAG_LINK - records directory entry link
+ * - EXT4_FC_TAG_CREAT - records inode and directory entry creation
+ *
+ * (B) File specific data range updates:
+ *
+ * - EXT4_FC_TAG_ADD_RANGE - records addition of new blocks to an inode
+ * - EXT4_FC_TAG_DEL_RANGE - records deletion of blocks from an inode
+ *
+ * (C) Inode metadata (mtime / ctime etc):
+ *
+ * - EXT4_FC_TAG_INODE - record the inode that should be replayed
+ * during recovery. Note that iblocks field is
+ * not replayed and instead derived during
+ * replay.
+ * Commit Operation
+ * ----------------
+ * With fast commits, we maintain all the directory entry operations in the
+ * order in which they are issued in an in-memory queue. This queue is flushed
+ * to disk during the commit operation. We also maintain a list of inodes
+ * that need to be committed during a fast commit in another in memory queue of
+ * inodes. During the commit operation, we commit in the following order:
+ *
+ * [1] Lock inodes for any further data updates by setting COMMITTING state
+ * [2] Submit data buffers of all the inodes
+ * [3] Wait for [2] to complete
+ * [4] Commit all the directory entry updates in the fast commit space
+ * [5] Commit all the changed inode structures
+ * [6] Write tail tag (this tag ensures the atomicity, please read the following
+ * section for more details).
+ * [7] Wait for [4], [5] and [6] to complete.
+ *
+ * All the inode updates must call ext4_fc_start_update() before starting an
+ * update. If such an ongoing update is present, fast commit waits for it to
+ * complete. The completion of such an update is marked by
+ * ext4_fc_stop_update().
+ *
+ * Fast Commit Ineligibility
+ * -------------------------
+ * Not all operations are supported by fast commits today (e.g extended
+ * attributes). Fast commit ineligiblity is marked by calling one of the
+ * two following functions:
+ *
+ * - ext4_fc_mark_ineligible(): This makes next fast commit operation to fall
+ * back to full commit. This is useful in case of transient errors.
+ *
+ * - ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() - This makes all
+ * the fast commits happening between ext4_fc_start_ineligible() and
+ * ext4_fc_stop_ineligible() and one fast commit after the call to
+ * ext4_fc_stop_ineligible() to fall back to full commits. It is important to
+ * make one more fast commit to fall back to full commit after stop call so
+ * that it guaranteed that the fast commit ineligible operation contained
+ * within ext4_fc_start_ineligible() and ext4_fc_stop_ineligible() is
+ * followed by at least 1 full commit.
+ *
+ * Atomicity of commits
+ * --------------------
+ * In order to gaurantee atomicity during the commit operation, fast commit
+ * uses "EXT4_FC_TAG_TAIL" tag that marks a fast commit as complete. Tail
+ * tag contains CRC of the contents and TID of the transaction after which
+ * this fast commit should be applied. Recovery code replays fast commit
+ * logs only if there's at least 1 valid tail present. For every fast commit
+ * operation, there is 1 tail. This means, we may end up with multiple tails
+ * in the fast commit space. Here's an example:
+ *
+ * - Create a new file A and remove existing file B
+ * - fsync()
+ * - Append contents to file A
+ * - Truncate file A
+ * - fsync()
+ *
+ * The fast commit space at the end of above operations would look like this:
+ * [HEAD] [CREAT A] [UNLINK B] [TAIL] [ADD_RANGE A] [DEL_RANGE A] [TAIL]
+ * |<--- Fast Commit 1 --->|<--- Fast Commit 2 ---->|
+ *
+ * Replay code should thus check for all the valid tails in the FC area.
+ *
+ * TODOs
+ * -----
+ * 1) Make fast commit atomic updates more fine grained. Today, a fast commit
+ * eligible update must be protected within ext4_fc_start_update() and
+ * ext4_fc_stop_update(). These routines are called at much higher
+ * routines. This can be made more fine grained by combining with
+ * ext4_journal_start().
+ *
+ * 2) Same above for ext4_fc_start_ineligible() and ext4_fc_stop_ineligible()
+ *
+ * 3) Handle more ineligible cases.
+ */
+
+#include <trace/events/ext4.h>
+static struct kmem_cache *ext4_fc_dentry_cachep;
+
+static void ext4_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
+{
+ BUFFER_TRACE(bh, "");
+ if (uptodate) {
+ ext4_debug("%s: Block %lld up-to-date",
+ __func__, bh->b_blocknr);
+ set_buffer_uptodate(bh);
+ } else {
+ ext4_debug("%s: Block %lld not up-to-date",
+ __func__, bh->b_blocknr);
+ clear_buffer_uptodate(bh);
+ }
+
+ unlock_buffer(bh);
+}
+
+static inline void ext4_fc_reset_inode(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ ei->i_fc_lblk_start = 0;
+ ei->i_fc_lblk_len = 0;
+}
+
+void ext4_fc_init_inode(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ ext4_fc_reset_inode(inode);
+ ext4_clear_inode_state(inode, EXT4_STATE_FC_COMMITTING);
+ INIT_LIST_HEAD(&ei->i_fc_list);
+ init_waitqueue_head(&ei->i_fc_wait);
+ atomic_set(&ei->i_fc_updates, 0);
+ ei->i_fc_committed_subtid = 0;
+}
+
+/*
+ * Inform Ext4's fast about start of an inode update
+ *
+ * This function is called by the high level call VFS callbacks before
+ * performing any inode update. This function blocks if there's an ongoing
+ * fast commit on the inode in question.
+ */
+void ext4_fc_start_update(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return;
+
+restart:
+ spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+ if (list_empty(&ei->i_fc_list))
+ goto out;
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
+ wait_queue_head_t *wq;
+#if (BITS_PER_LONG < 64)
+ DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
+ EXT4_STATE_FC_COMMITTING);
+ wq = bit_waitqueue(&ei->i_state_flags,
+ EXT4_STATE_FC_COMMITTING);
+#else
+ DEFINE_WAIT_BIT(wait, &ei->i_flags,
+ EXT4_STATE_FC_COMMITTING);
+ wq = bit_waitqueue(&ei->i_flags,
+ EXT4_STATE_FC_COMMITTING);
+#endif
+ prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+ schedule();
+ finish_wait(wq, &wait.wq_entry);
+ goto restart;
+ }
+out:
+ atomic_inc(&ei->i_fc_updates);
+ spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+}
+
+/*
+ * Stop inode update and wake up waiting fast commits if any.
+ */
+void ext4_fc_stop_update(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return;
+
+ if (atomic_dec_and_test(&ei->i_fc_updates))
+ wake_up_all(&ei->i_fc_wait);
+}
+
+/*
+ * Remove inode from fast commit list. If the inode is being committed
+ * we wait until inode commit is done.
+ */
+void ext4_fc_del(struct inode *inode)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+
+ if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return;
+
+
+ if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return;
+
+restart:
+ spin_lock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+ if (list_empty(&ei->i_fc_list)) {
+ spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+ return;
+ }
+
+ if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
+ wait_queue_head_t *wq;
+#if (BITS_PER_LONG < 64)
+ DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
+ EXT4_STATE_FC_COMMITTING);
+ wq = bit_waitqueue(&ei->i_state_flags,
+ EXT4_STATE_FC_COMMITTING);
+#else
+ DEFINE_WAIT_BIT(wait, &ei->i_flags,
+ EXT4_STATE_FC_COMMITTING);
+ wq = bit_waitqueue(&ei->i_flags,
+ EXT4_STATE_FC_COMMITTING);
+#endif
+ prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+ spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+ schedule();
+ finish_wait(wq, &wait.wq_entry);
+ goto restart;
+ }
+ if (!list_empty(&ei->i_fc_list))
+ list_del_init(&ei->i_fc_list);
+ spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+}
+
+/*
+ * Mark file system as fast commit ineligible. This means that next commit
+ * operation would result in a full jbd2 commit.
+ */
+void ext4_fc_mark_ineligible(struct super_block *sb, int reason)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ sbi->s_mount_state |= EXT4_FC_INELIGIBLE;
+ WARN_ON(reason >= EXT4_FC_REASON_MAX);
+ sbi->s_fc_stats.fc_ineligible_reason_count[reason]++;
+}
+
+/*
+ * Start a fast commit ineligible update. Any commits that happen while
+ * such an operation is in progress fall back to full commits.
+ */
+void ext4_fc_start_ineligible(struct super_block *sb, int reason)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ WARN_ON(reason >= EXT4_FC_REASON_MAX);
+ sbi->s_fc_stats.fc_ineligible_reason_count[reason]++;
+ atomic_inc(&sbi->s_fc_ineligible_updates);
+}
+
+/*
+ * Stop a fast commit ineligible update. We set EXT4_FC_INELIGIBLE flag here
+ * to ensure that after stopping the ineligible update, at least one full
+ * commit takes place.
+ */
+void ext4_fc_stop_ineligible(struct super_block *sb)
+{
+ EXT4_SB(sb)->s_mount_state |= EXT4_FC_INELIGIBLE;
+ atomic_dec(&EXT4_SB(sb)->s_fc_ineligible_updates);
+}
+
+static inline int ext4_fc_is_ineligible(struct super_block *sb)
+{
+ return (EXT4_SB(sb)->s_mount_state & EXT4_FC_INELIGIBLE) ||
+ atomic_read(&EXT4_SB(sb)->s_fc_ineligible_updates);
+}
+
+/*
+ * Generic fast commit tracking function. If this is the first time this we are
+ * called after a full commit, we initialize fast commit fields and then call
+ * __fc_track_fn() with update = 0. If we have already been called after a full
+ * commit, we pass update = 1. Based on that, the track function can determine
+ * if it needs to track a field for the first time or if it needs to just
+ * update the previously tracked value.
+ *
+ * If enqueue is set, this function enqueues the inode in fast commit list.
+ */
+static int ext4_fc_track_template(
+ struct inode *inode, int (*__fc_track_fn)(struct inode *, void *, bool),
+ void *args, int enqueue)
+{
+ tid_t running_txn_tid;
+ bool update = false;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ int ret;
+
+ if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
+ return -EOPNOTSUPP;
+
+ if (ext4_fc_is_ineligible(inode->i_sb))
+ return -EINVAL;
+
+ running_txn_tid = sbi->s_journal ?
+ sbi->s_journal->j_commit_sequence + 1 : 0;
+
+ mutex_lock(&ei->i_fc_lock);
+ if (running_txn_tid == ei->i_sync_tid) {
+ update = true;
+ } else {
+ ext4_fc_reset_inode(inode);
+ ei->i_sync_tid = running_txn_tid;
+ }
+ ret = __fc_track_fn(inode, args, update);
+ mutex_unlock(&ei->i_fc_lock);
+
+ if (!enqueue)
+ return ret;
+
+ spin_lock(&sbi->s_fc_lock);
+ if (list_empty(&EXT4_I(inode)->i_fc_list))
+ list_add_tail(&EXT4_I(inode)->i_fc_list,
+ (sbi->s_mount_state & EXT4_FC_COMMITTING) ?
+ &sbi->s_fc_q[FC_Q_STAGING] :
+ &sbi->s_fc_q[FC_Q_MAIN]);
+ spin_unlock(&sbi->s_fc_lock);
+
+ return ret;
+}
+
+struct __track_dentry_update_args {
+ struct dentry *dentry;
+ int op;
+};
+
+/* __track_fn for directory entry updates. Called with ei->i_fc_lock. */
+static int __track_dentry_update(struct inode *inode, void *arg, bool update)
+{
+ struct ext4_fc_dentry_update *node;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct __track_dentry_update_args *dentry_update =
+ (struct __track_dentry_update_args *)arg;
+ struct dentry *dentry = dentry_update->dentry;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+ mutex_unlock(&ei->i_fc_lock);
+ node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS);
+ if (!node) {
+ ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_MEM);
+ mutex_lock(&ei->i_fc_lock);
+ return -ENOMEM;
+ }
+
+ node->fcd_op = dentry_update->op;
+ node->fcd_parent = dentry->d_parent->d_inode->i_ino;
+ node->fcd_ino = inode->i_ino;
+ if (dentry->d_name.len > DNAME_INLINE_LEN) {
+ node->fcd_name.name = kmalloc(dentry->d_name.len, GFP_NOFS);
+ if (!node->fcd_name.name) {
+ kmem_cache_free(ext4_fc_dentry_cachep, node);
+ ext4_fc_mark_ineligible(inode->i_sb,
+ EXT4_FC_REASON_MEM);
+ mutex_lock(&ei->i_fc_lock);
+ return -ENOMEM;
+ }
+ memcpy((u8 *)node->fcd_name.name, dentry->d_name.name,
+ dentry->d_name.len);
+ } else {
+ memcpy(node->fcd_iname, dentry->d_name.name,
+ dentry->d_name.len);
+ node->fcd_name.name = node->fcd_iname;
+ }
+ node->fcd_name.len = dentry->d_name.len;
+
+ spin_lock(&sbi->s_fc_lock);
+ if (sbi->s_mount_state & EXT4_FC_COMMITTING)
+ list_add_tail(&node->fcd_list,
+ &sbi->s_fc_dentry_q[FC_Q_STAGING]);
+ else
+ list_add_tail(&node->fcd_list, &sbi->s_fc_dentry_q[FC_Q_MAIN]);
+ spin_unlock(&sbi->s_fc_lock);
+ mutex_lock(&ei->i_fc_lock);
+
+ return 0;
+}
+
+void ext4_fc_track_unlink(struct inode *inode, struct dentry *dentry)
+{
+ struct __track_dentry_update_args args;
+ int ret;
+
+ args.dentry = dentry;
+ args.op = EXT4_FC_TAG_UNLINK;
+
+ ret = ext4_fc_track_template(inode, __track_dentry_update,
+ (void *)&args, 0);
+ trace_ext4_fc_track_unlink(inode, dentry, ret);
+}
+
+void ext4_fc_track_link(struct inode *inode, struct dentry *dentry)
+{
+ struct __track_dentry_update_args args;
+ int ret;
+
+ args.dentry = dentry;
+ args.op = EXT4_FC_TAG_LINK;
+
+ ret = ext4_fc_track_template(inode, __track_dentry_update,
+ (void *)&args, 0);
+ trace_ext4_fc_track_link(inode, dentry, ret);
+}
+
+void ext4_fc_track_create(struct inode *inode, struct dentry *dentry)
+{
+ struct __track_dentry_update_args args;
+ int ret;
+
+ args.dentry = dentry;
+ args.op = EXT4_FC_TAG_CREAT;
+
+ ret = ext4_fc_track_template(inode, __track_dentry_update,
+ (void *)&args, 0);
+ trace_ext4_fc_track_create(inode, dentry, ret);
+}
+
+/* __track_fn for inode tracking */
+static int __track_inode(struct inode *inode, void *arg, bool update)
+{
+ if (update)
+ return -EEXIST;
+
+ EXT4_I(inode)->i_fc_lblk_len = 0;
+
+ return 0;
+}
+
+void ext4_fc_track_inode(struct inode *inode)
+{
+ int ret;
+
+ if (S_ISDIR(inode->i_mode))
+ return;
+
+ ret = ext4_fc_track_template(inode, __track_inode, NULL, 1);
+ trace_ext4_fc_track_inode(inode, ret);
+}
+
+struct __track_range_args {
+ ext4_lblk_t start, end;
+};
+
+/* __track_fn for tracking data updates */
+static int __track_range(struct inode *inode, void *arg, bool update)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ ext4_lblk_t oldstart;
+ struct __track_range_args *__arg =
+ (struct __track_range_args *)arg;
+
+ if (inode->i_ino < EXT4_FIRST_INO(inode->i_sb)) {
+ ext4_debug("Special inode %ld being modified\n", inode->i_ino);
+ return -ECANCELED;
+ }
+
+ oldstart = ei->i_fc_lblk_start;
+
+ if (update && ei->i_fc_lblk_len > 0) {
+ ei->i_fc_lblk_start = min(ei->i_fc_lblk_start, __arg->start);
+ ei->i_fc_lblk_len =
+ max(oldstart + ei->i_fc_lblk_len - 1, __arg->end) -
+ ei->i_fc_lblk_start + 1;
+ } else {
+ ei->i_fc_lblk_start = __arg->start;
+ ei->i_fc_lblk_len = __arg->end - __arg->start + 1;
+ }
+
+ return 0;
+}
+
+void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start,
+ ext4_lblk_t end)
+{
+ struct __track_range_args args;
+ int ret;
+
+ if (S_ISDIR(inode->i_mode))
+ return;
+
+ args.start = start;
+ args.end = end;
+
+ ret = ext4_fc_track_template(inode, __track_range, &args, 1);
+
+ trace_ext4_fc_track_range(inode, start, end, ret);
+}
+
+static void ext4_fc_submit_bh(struct super_block *sb)
+{
+ int write_flags = REQ_SYNC;
+ struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh;
+
+ if (test_opt(sb, BARRIER))
+ write_flags |= REQ_FUA | REQ_PREFLUSH;
+ lock_buffer(bh);
+ clear_buffer_dirty(bh);
+ set_buffer_uptodate(bh);
+ bh->b_end_io = ext4_end_buffer_io_sync;
+ submit_bh(REQ_OP_WRITE, write_flags, bh);
+ EXT4_SB(sb)->s_fc_bh = NULL;
+}
+
+/* Ext4 commit path routines */
+
+/* memzero and update CRC */
+static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len,
+ u32 *crc)
+{
+ void *ret;
+
+ ret = memset(dst, 0, len);
+ if (crc)
+ *crc = ext4_chksum(EXT4_SB(sb), *crc, dst, len);
+ return ret;
+}
+
+/*
+ * Allocate len bytes on a fast commit buffer.
+ *
+ * During the commit time this function is used to manage fast commit
+ * block space. We don't split a fast commit log onto different
+ * blocks. So this function makes sure that if there's not enough space
+ * on the current block, the remaining space in the current block is
+ * marked as unused by adding EXT4_FC_TAG_PAD tag. In that case,
+ * new block is from jbd2 and CRC is updated to reflect the padding
+ * we added.
+ */
+static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc)
+{
+ struct ext4_fc_tl *tl;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct buffer_head *bh;
+ int bsize = sbi->s_journal->j_blocksize;
+ int ret, off = sbi->s_fc_bytes % bsize;
+ int pad_len;
+
+ /*
+ * After allocating len, we should have space at least for a 0 byte
+ * padding.
+ */
+ if (len + sizeof(struct ext4_fc_tl) > bsize)
+ return NULL;
+
+ if (bsize - off - 1 > len + sizeof(struct ext4_fc_tl)) {
+ /*
+ * Only allocate from current buffer if we have enough space for
+ * this request AND we have space to add a zero byte padding.
+ */
+ if (!sbi->s_fc_bh) {
+ ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
+ if (ret)
+ return NULL;
+ sbi->s_fc_bh = bh;
+ }
+ sbi->s_fc_bytes += len;
+ return sbi->s_fc_bh->b_data + off;
+ }
+ /* Need to add PAD tag */
+ tl = (struct ext4_fc_tl *)(sbi->s_fc_bh->b_data + off);
+ tl->fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD);
+ pad_len = bsize - off - 1 - sizeof(struct ext4_fc_tl);
+ tl->fc_len = cpu_to_le16(pad_len);
+ if (crc)
+ *crc = ext4_chksum(sbi, *crc, tl, sizeof(*tl));
+ if (pad_len > 0)
+ ext4_fc_memzero(sb, tl + 1, pad_len, crc);
+ ext4_fc_submit_bh(sb);
+
+ ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
+ if (ret)
+ return NULL;
+ sbi->s_fc_bh = bh;
+ sbi->s_fc_bytes = (sbi->s_fc_bytes / bsize + 1) * bsize + len;
+ return sbi->s_fc_bh->b_data;
+}
+
+/* memcpy to fc reserved space and update CRC */
+static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src,
+ int len, u32 *crc)
+{
+ if (crc)
+ *crc = ext4_chksum(EXT4_SB(sb), *crc, src, len);
+ return memcpy(dst, src, len);
+}
+
+/*
+ * Complete a fast commit by writing tail tag.
+ *
+ * Writing tail tag marks the end of a fast commit. In order to guarantee
+ * atomicity, after writing tail tag, even if there's space remaining
+ * in the block, next commit shouldn't use it. That's why tail tag
+ * has the length as that of the remaining space on the block.
+ */
+static int ext4_fc_write_tail(struct super_block *sb, u32 crc)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_fc_tl tl;
+ struct ext4_fc_tail tail;
+ int off, bsize = sbi->s_journal->j_blocksize;
+ u8 *dst;
+
+ /*
+ * ext4_fc_reserve_space takes care of allocating an extra block if
+ * there's no enough space on this block for accommodating this tail.
+ */
+ dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(tail), &crc);
+ if (!dst)
+ return -ENOSPC;
+
+ off = sbi->s_fc_bytes % bsize;
+
+ tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_TAIL);
+ tl.fc_len = cpu_to_le16(bsize - off - 1 + sizeof(struct ext4_fc_tail));
+ sbi->s_fc_bytes = round_up(sbi->s_fc_bytes, bsize);
+
+ ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), &crc);
+ dst += sizeof(tl);
+ tail.fc_tid = cpu_to_le32(sbi->s_journal->j_running_transaction->t_tid);
+ ext4_fc_memcpy(sb, dst, &tail.fc_tid, sizeof(tail.fc_tid), &crc);
+ dst += sizeof(tail.fc_tid);
+ tail.fc_crc = cpu_to_le32(crc);
+ ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL);
+
+ ext4_fc_submit_bh(sb);
+
+ return 0;
+}
+
+/*
+ * Adds tag, length, value and updates CRC. Returns true if tlv was added.
+ * Returns false if there's not enough space.
+ */
+static bool ext4_fc_add_tlv(struct super_block *sb, u16 tag, u16 len, u8 *val,
+ u32 *crc)
+{
+ struct ext4_fc_tl tl;
+ u8 *dst;
+
+ dst = ext4_fc_reserve_space(sb, sizeof(tl) + len, crc);
+ if (!dst)
+ return false;
+
+ tl.fc_tag = cpu_to_le16(tag);
+ tl.fc_len = cpu_to_le16(len);
+
+ ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc);
+ ext4_fc_memcpy(sb, dst + sizeof(tl), val, len, crc);
+
+ return true;
+}
+
+/* Same as above, but adds dentry tlv. */
+static bool ext4_fc_add_dentry_tlv(struct super_block *sb, u16 tag,
+ int parent_ino, int ino, int dlen,
+ const unsigned char *dname,
+ u32 *crc)
+{
+ struct ext4_fc_dentry_info fcd;
+ struct ext4_fc_tl tl;
+ u8 *dst = ext4_fc_reserve_space(sb, sizeof(tl) + sizeof(fcd) + dlen,
+ crc);
+
+ if (!dst)
+ return false;
+
+ fcd.fc_parent_ino = cpu_to_le32(parent_ino);
+ fcd.fc_ino = cpu_to_le32(ino);
+ tl.fc_tag = cpu_to_le16(tag);
+ tl.fc_len = cpu_to_le16(sizeof(fcd) + dlen);
+ ext4_fc_memcpy(sb, dst, &tl, sizeof(tl), crc);
+ dst += sizeof(tl);
+ ext4_fc_memcpy(sb, dst, &fcd, sizeof(fcd), crc);
+ dst += sizeof(fcd);
+ ext4_fc_memcpy(sb, dst, dname, dlen, crc);
+ dst += dlen;
+
+ return true;
+}
+
+/*
+ * Writes inode in the fast commit space under TLV with tag @tag.
+ * Returns 0 on success, error on failure.
+ */
+static int ext4_fc_write_inode(struct inode *inode, u32 *crc)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ int inode_len = EXT4_GOOD_OLD_INODE_SIZE;
+ int ret;
+ struct ext4_iloc iloc;
+ struct ext4_fc_inode fc_inode;
+ struct ext4_fc_tl tl;
+ u8 *dst;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE)
+ inode_len += ei->i_extra_isize;
+
+ fc_inode.fc_ino = cpu_to_le32(inode->i_ino);
+ tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_INODE);
+ tl.fc_len = cpu_to_le16(inode_len + sizeof(fc_inode.fc_ino));
+
+ dst = ext4_fc_reserve_space(inode->i_sb,
+ sizeof(tl) + inode_len + sizeof(fc_inode.fc_ino), crc);
+ if (!dst)
+ return -ECANCELED;
+
+ if (!ext4_fc_memcpy(inode->i_sb, dst, &tl, sizeof(tl), crc))
+ return -ECANCELED;
+ dst += sizeof(tl);
+ if (!ext4_fc_memcpy(inode->i_sb, dst, &fc_inode, sizeof(fc_inode), crc))
+ return -ECANCELED;
+ dst += sizeof(fc_inode);
+ if (!ext4_fc_memcpy(inode->i_sb, dst, (u8 *)ext4_raw_inode(&iloc),
+ inode_len, crc))
+ return -ECANCELED;
+
+ return 0;
+}
+
+/*
+ * Writes updated data ranges for the inode in question. Updates CRC.
+ * Returns 0 on success, error otherwise.
+ */
+static int ext4_fc_write_inode_data(struct inode *inode, u32 *crc)
+{
+ ext4_lblk_t old_blk_size, cur_lblk_off, new_blk_size;
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_map_blocks map;
+ struct ext4_fc_add_range fc_ext;
+ struct ext4_fc_del_range lrange;
+ struct ext4_extent *ex;
+ int ret;
+
+ mutex_lock(&ei->i_fc_lock);
+ if (ei->i_fc_lblk_len == 0) {
+ mutex_unlock(&ei->i_fc_lock);
+ return 0;
+ }
+ old_blk_size = ei->i_fc_lblk_start;
+ new_blk_size = ei->i_fc_lblk_start + ei->i_fc_lblk_len - 1;
+ ei->i_fc_lblk_len = 0;
+ mutex_unlock(&ei->i_fc_lock);
+
+ cur_lblk_off = old_blk_size;
+ jbd_debug(1, "%s: will try writing %d to %d for inode %ld\n",
+ __func__, cur_lblk_off, new_blk_size, inode->i_ino);
+
+ while (cur_lblk_off <= new_blk_size) {
+ map.m_lblk = cur_lblk_off;
+ map.m_len = new_blk_size - cur_lblk_off + 1;
+ ret = ext4_map_blocks(NULL, inode, &map, 0);
+ if (ret < 0)
+ return -ECANCELED;
+
+ if (map.m_len == 0) {
+ cur_lblk_off++;
+ continue;
+ }
+
+ if (ret == 0) {
+ lrange.fc_ino = cpu_to_le32(inode->i_ino);
+ lrange.fc_lblk = cpu_to_le32(map.m_lblk);
+ lrange.fc_len = cpu_to_le32(map.m_len);
+ if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_DEL_RANGE,
+ sizeof(lrange), (u8 *)&lrange, crc))
+ return -ENOSPC;
+ } else {
+ fc_ext.fc_ino = cpu_to_le32(inode->i_ino);
+ ex = (struct ext4_extent *)&fc_ext.fc_ex;
+ ex->ee_block = cpu_to_le32(map.m_lblk);
+ ex->ee_len = cpu_to_le16(map.m_len);
+ ext4_ext_store_pblock(ex, map.m_pblk);
+ if (map.m_flags & EXT4_MAP_UNWRITTEN)
+ ext4_ext_mark_unwritten(ex);
+ else
+ ext4_ext_mark_initialized(ex);
+ if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_ADD_RANGE,
+ sizeof(fc_ext), (u8 *)&fc_ext, crc))
+ return -ENOSPC;
+ }
+
+ cur_lblk_off += map.m_len;
+ }
+
+ return 0;
+}
+
+
+/* Submit data for all the fast commit inodes */
+static int ext4_fc_submit_inode_data_all(journal_t *journal)
+{
+ struct super_block *sb = (struct super_block *)(journal->j_private);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_inode_info *ei;
+ struct list_head *pos;
+ int ret = 0;
+
+ spin_lock(&sbi->s_fc_lock);
+ sbi->s_mount_state |= EXT4_FC_COMMITTING;
+ list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) {
+ ei = list_entry(pos, struct ext4_inode_info, i_fc_list);
+ ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING);
+ while (atomic_read(&ei->i_fc_updates)) {
+ DEFINE_WAIT(wait);
+
+ prepare_to_wait(&ei->i_fc_wait, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&ei->i_fc_updates)) {
+ spin_unlock(&sbi->s_fc_lock);
+ schedule();
+ spin_lock(&sbi->s_fc_lock);
+ }
+ finish_wait(&ei->i_fc_wait, &wait);
+ }
+ spin_unlock(&sbi->s_fc_lock);
+ ret = jbd2_submit_inode_data(ei->jinode);
+ if (ret)
+ return ret;
+ spin_lock(&sbi->s_fc_lock);
+ }
+ spin_unlock(&sbi->s_fc_lock);
+
+ return ret;
+}
+
+/* Wait for completion of data for all the fast commit inodes */
+static int ext4_fc_wait_inode_data_all(journal_t *journal)
+{
+ struct super_block *sb = (struct super_block *)(journal->j_private);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_inode_info *pos, *n;
+ int ret = 0;
+
+ spin_lock(&sbi->s_fc_lock);
+ list_for_each_entry_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
+ if (!ext4_test_inode_state(&pos->vfs_inode,
+ EXT4_STATE_FC_COMMITTING))
+ continue;
+ spin_unlock(&sbi->s_fc_lock);
+
+ ret = jbd2_wait_inode_data(journal, pos->jinode);
+ if (ret)
+ return ret;
+ spin_lock(&sbi->s_fc_lock);
+ }
+ spin_unlock(&sbi->s_fc_lock);
+
+ return 0;
+}
+
+/* Commit all the directory entry updates */
+static int ext4_fc_commit_dentry_updates(journal_t *journal, u32 *crc)
+{
+ struct super_block *sb = (struct super_block *)(journal->j_private);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_fc_dentry_update *fc_dentry;
+ struct inode *inode;
+ struct list_head *pos, *n, *fcd_pos, *fcd_n;
+ struct ext4_inode_info *ei;
+ int ret;
+
+ if (list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN]))
+ return 0;
+ list_for_each_safe(fcd_pos, fcd_n, &sbi->s_fc_dentry_q[FC_Q_MAIN]) {
+ fc_dentry = list_entry(fcd_pos, struct ext4_fc_dentry_update,
+ fcd_list);
+ if (fc_dentry->fcd_op != EXT4_FC_TAG_CREAT) {
+ spin_unlock(&sbi->s_fc_lock);
+ if (!ext4_fc_add_dentry_tlv(
+ sb, fc_dentry->fcd_op,
+ fc_dentry->fcd_parent, fc_dentry->fcd_ino,
+ fc_dentry->fcd_name.len,
+ fc_dentry->fcd_name.name, crc)) {
+ ret = -ENOSPC;
+ goto lock_and_exit;
+ }
+ spin_lock(&sbi->s_fc_lock);
+ continue;
+ }
+
+ inode = NULL;
+ list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) {
+ ei = list_entry(pos, struct ext4_inode_info, i_fc_list);
+ if (ei->vfs_inode.i_ino == fc_dentry->fcd_ino) {
+ inode = &ei->vfs_inode;
+ break;
+ }
+ }
+ /*
+ * If we don't find inode in our list, then it was deleted,
+ * in which case, we don't need to record it's create tag.
+ */
+ if (!inode)
+ continue;
+ spin_unlock(&sbi->s_fc_lock);
+
+ /*
+ * We first write the inode and then the create dirent. This
+ * allows the recovery code to create an unnamed inode first
+ * and then link it to a directory entry. This allows us
+ * to use namei.c routines almost as is and simplifies
+ * the recovery code.
+ */
+ ret = ext4_fc_write_inode(inode, crc);
+ if (ret)
+ goto lock_and_exit;
+
+ ret = ext4_fc_write_inode_data(inode, crc);
+ if (ret)
+ goto lock_and_exit;
+
+ if (!ext4_fc_add_dentry_tlv(
+ sb, fc_dentry->fcd_op,
+ fc_dentry->fcd_parent, fc_dentry->fcd_ino,
+ fc_dentry->fcd_name.len,
+ fc_dentry->fcd_name.name, crc)) {
+ spin_lock(&sbi->s_fc_lock);
+ ret = -ENOSPC;
+ goto lock_and_exit;
+ }
+
+ spin_lock(&sbi->s_fc_lock);
+ }
+ return 0;
+lock_and_exit:
+ spin_lock(&sbi->s_fc_lock);
+ return ret;
+}
+
+static int ext4_fc_perform_commit(journal_t *journal)
+{
+ struct super_block *sb = (struct super_block *)(journal->j_private);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_inode_info *iter;
+ struct ext4_fc_head head;
+ struct list_head *pos;
+ struct inode *inode;
+ struct blk_plug plug;
+ int ret = 0;
+ u32 crc = 0;
+
+ ret = ext4_fc_submit_inode_data_all(journal);
+ if (ret)
+ return ret;
+
+ ret = ext4_fc_wait_inode_data_all(journal);
+ if (ret)
+ return ret;
+
+ blk_start_plug(&plug);
+ if (sbi->s_fc_bytes == 0) {
+ /*
+ * Add a head tag only if this is the first fast commit
+ * in this TID.
+ */
+ head.fc_features = cpu_to_le32(EXT4_FC_SUPPORTED_FEATURES);
+ head.fc_tid = cpu_to_le32(
+ sbi->s_journal->j_running_transaction->t_tid);
+ if (!ext4_fc_add_tlv(sb, EXT4_FC_TAG_HEAD, sizeof(head),
+ (u8 *)&head, &crc))
+ goto out;
+ }
+
+ spin_lock(&sbi->s_fc_lock);
+ ret = ext4_fc_commit_dentry_updates(journal, &crc);
+ if (ret) {
+ spin_unlock(&sbi->s_fc_lock);
+ goto out;
+ }
+
+ list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) {
+ iter = list_entry(pos, struct ext4_inode_info, i_fc_list);
+ inode = &iter->vfs_inode;
+ if (!ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING))
+ continue;
+
+ spin_unlock(&sbi->s_fc_lock);
+ ret = ext4_fc_write_inode_data(inode, &crc);
+ if (ret)
+ goto out;
+ ret = ext4_fc_write_inode(inode, &crc);
+ if (ret)
+ goto out;
+ spin_lock(&sbi->s_fc_lock);
+ EXT4_I(inode)->i_fc_committed_subtid =
+ atomic_read(&sbi->s_fc_subtid);
+ }
+ spin_unlock(&sbi->s_fc_lock);
+
+ ret = ext4_fc_write_tail(sb, crc);
+
+out:
+ blk_finish_plug(&plug);
+ return ret;
+}
+
+/*
+ * The main commit entry point. Performs a fast commit for transaction
+ * commit_tid if needed. If it's not possible to perform a fast commit
+ * due to various reasons, we fall back to full commit. Returns 0
+ * on success, error otherwise.
+ */
+int ext4_fc_commit(journal_t *journal, tid_t commit_tid)
+{
+ struct super_block *sb = (struct super_block *)(journal->j_private);
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ int nblks = 0, ret, bsize = journal->j_blocksize;
+ int subtid = atomic_read(&sbi->s_fc_subtid);
+ int reason = EXT4_FC_REASON_OK, fc_bufs_before = 0;
+ ktime_t start_time, commit_time;
+
+ trace_ext4_fc_commit_start(sb);
+
+ start_time = ktime_get();
+
+ if (!test_opt2(sb, JOURNAL_FAST_COMMIT) ||
+ (ext4_fc_is_ineligible(sb))) {
+ reason = EXT4_FC_REASON_INELIGIBLE;
+ goto out;
+ }
+
+restart_fc:
+ ret = jbd2_fc_begin_commit(journal, commit_tid);
+ if (ret == -EALREADY) {
+ /* There was an ongoing commit, check if we need to restart */
+ if (atomic_read(&sbi->s_fc_subtid) <= subtid &&
+ commit_tid > journal->j_commit_sequence)
+ goto restart_fc;
+ reason = EXT4_FC_REASON_ALREADY_COMMITTED;
+ goto out;
+ } else if (ret) {
+ sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
+ reason = EXT4_FC_REASON_FC_START_FAILED;
+ goto out;
+ }
+
+ fc_bufs_before = (sbi->s_fc_bytes + bsize - 1) / bsize;
+ ret = ext4_fc_perform_commit(journal);
+ if (ret < 0) {
+ sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
+ reason = EXT4_FC_REASON_FC_FAILED;
+ goto out;
+ }
+ nblks = (sbi->s_fc_bytes + bsize - 1) / bsize - fc_bufs_before;
+ ret = jbd2_fc_wait_bufs(journal, nblks);
+ if (ret < 0) {
+ sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
+ reason = EXT4_FC_REASON_FC_FAILED;
+ goto out;
+ }
+ atomic_inc(&sbi->s_fc_subtid);
+ jbd2_fc_end_commit(journal);
+out:
+ /* Has any ineligible update happened since we started? */
+ if (reason == EXT4_FC_REASON_OK && ext4_fc_is_ineligible(sb)) {
+ sbi->s_fc_stats.fc_ineligible_reason_count[EXT4_FC_COMMIT_FAILED]++;
+ reason = EXT4_FC_REASON_INELIGIBLE;
+ }
+
+ spin_lock(&sbi->s_fc_lock);
+ if (reason != EXT4_FC_REASON_OK &&
+ reason != EXT4_FC_REASON_ALREADY_COMMITTED) {
+ sbi->s_fc_stats.fc_ineligible_commits++;
+ } else {
+ sbi->s_fc_stats.fc_num_commits++;
+ sbi->s_fc_stats.fc_numblks += nblks;
+ }
+ spin_unlock(&sbi->s_fc_lock);
+ nblks = (reason == EXT4_FC_REASON_OK) ? nblks : 0;
+ trace_ext4_fc_commit_stop(sb, nblks, reason);
+ commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
+ /*
+ * weight the commit time higher than the average time so we don't
+ * react too strongly to vast changes in the commit time
+ */
+ if (likely(sbi->s_fc_avg_commit_time))
+ sbi->s_fc_avg_commit_time = (commit_time +
+ sbi->s_fc_avg_commit_time * 3) / 4;
+ else
+ sbi->s_fc_avg_commit_time = commit_time;
+ jbd_debug(1,
+ "Fast commit ended with blks = %d, reason = %d, subtid - %d",
+ nblks, reason, subtid);
+ if (reason == EXT4_FC_REASON_FC_FAILED)
+ return jbd2_fc_end_commit_fallback(journal, commit_tid);
+ if (reason == EXT4_FC_REASON_FC_START_FAILED ||
+ reason == EXT4_FC_REASON_INELIGIBLE)
+ return jbd2_complete_transaction(journal, commit_tid);
+ return 0;
+}
+
/*
* Fast commit cleanup routine. This is called after every fast commit and
* full commit. full is true if we are called after a full commit.
*/
static void ext4_fc_cleanup(journal_t *journal, int full)
{
+ struct super_block *sb = journal->j_private;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_inode_info *iter;
+ struct ext4_fc_dentry_update *fc_dentry;
+ struct list_head *pos, *n;
+
+ if (full && sbi->s_fc_bh)
+ sbi->s_fc_bh = NULL;
+
+ jbd2_fc_release_bufs(journal);
+
+ spin_lock(&sbi->s_fc_lock);
+ list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) {
+ iter = list_entry(pos, struct ext4_inode_info, i_fc_list);
+ list_del_init(&iter->i_fc_list);
+ ext4_clear_inode_state(&iter->vfs_inode,
+ EXT4_STATE_FC_COMMITTING);
+ ext4_fc_reset_inode(&iter->vfs_inode);
+ /* Make sure EXT4_STATE_FC_COMMITTING bit is clear */
+ smp_mb();
+#if (BITS_PER_LONG < 64)
+ wake_up_bit(&iter->i_state_flags, EXT4_STATE_FC_COMMITTING);
+#else
+ wake_up_bit(&iter->i_flags, EXT4_STATE_FC_COMMITTING);
+#endif
+ }
+
+ while (!list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN])) {
+ fc_dentry = list_first_entry(&sbi->s_fc_dentry_q[FC_Q_MAIN],
+ struct ext4_fc_dentry_update,
+ fcd_list);
+ list_del_init(&fc_dentry->fcd_list);
+ spin_unlock(&sbi->s_fc_lock);
+
+ if (fc_dentry->fcd_name.name &&
+ fc_dentry->fcd_name.len > DNAME_INLINE_LEN)
+ kfree(fc_dentry->fcd_name.name);
+ kmem_cache_free(ext4_fc_dentry_cachep, fc_dentry);
+ spin_lock(&sbi->s_fc_lock);
+ }
+
+ list_splice_init(&sbi->s_fc_dentry_q[FC_Q_STAGING],
+ &sbi->s_fc_dentry_q[FC_Q_MAIN]);
+ list_splice_init(&sbi->s_fc_q[FC_Q_STAGING],
+ &sbi->s_fc_q[FC_Q_STAGING]);
+
+ sbi->s_mount_state &= ~EXT4_FC_COMMITTING;
+ sbi->s_mount_state &= ~EXT4_FC_INELIGIBLE;
+
+ if (full)
+ sbi->s_fc_bytes = 0;
+ spin_unlock(&sbi->s_fc_lock);
+ trace_ext4_fc_stats(sb);
}
void ext4_fc_init(struct super_block *sb, journal_t *journal)
@@ -26,3 +1198,14 @@
ext4_clear_feature_fast_commit(sb);
}
}
+
+int __init ext4_fc_init_dentry_cache(void)
+{
+ ext4_fc_dentry_cachep = KMEM_CACHE(ext4_fc_dentry_update,
+ SLAB_RECLAIM_ACCOUNT);
+
+ if (ext4_fc_dentry_cachep == NULL)
+ return -ENOMEM;
+
+ return 0;
+}