Commit bdc8a53a authored by Xin Yin's avatar Xin Yin Committed by Theodore Ts'o
Browse files

ext4: fast commit may miss file actions 



in the follow scenario:
1. jbd start transaction n
2. task A get new handle for transaction n+1
3. task A do some actions and add inode to FC_Q_MAIN fc_q
4. jbd complete transaction n and clear FC_Q_MAIN fc_q
5. task A call fsync

Fast commit will lost the file actions during a full commit.

we should also add updates to staging queue during a full commit.
and in ext4_fc_cleanup(), when reset a inode's fc track range, check
it's i_sync_tid, if it bigger than current transaction tid, do not
rest it, or we will lost the track range.

And EXT4_MF_FC_COMMITTING is not needed anymore, so drop it.

Signed-off-by: default avatarXin Yin <yinxin.x@bytedance.com>
Link: https://lore.kernel.org/r/20220117093655.35160-3-yinxin.x@bytedance.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
parent e85c81ba

fs/ext4/ext4.h

+1 −4
Original line number Diff line number Diff line
@@ -1795,10 +1795,7 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) 
enum {

	EXT4_MF_MNTDIR_SAMPLED,

	EXT4_MF_FS_ABORTED,	/* Fatal error detected */

	EXT4_MF_FC_INELIGIBLE,	/* Fast commit ineligible */

	EXT4_MF_FC_COMMITTING	/* File system underoing a fast

				 * commit.

				 */

	EXT4_MF_FC_INELIGIBLE	/* Fast commit ineligible */

};



static inline void ext4_set_mount_flag(struct super_block *sb, int bit)

fs/ext4/fast_commit.c

+6 −5
Original line number Diff line number Diff line
@@ -375,7 +375,8 @@ static int ext4_fc_track_template( 
	spin_lock(&sbi->s_fc_lock);

	if (list_empty(&EXT4_I(inode)->i_fc_list))

		list_add_tail(&EXT4_I(inode)->i_fc_list,

				(ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_COMMITTING)) ?

				(sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||

				 sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING) ?

				&sbi->s_fc_q[FC_Q_STAGING] :

				&sbi->s_fc_q[FC_Q_MAIN]);

	spin_unlock(&sbi->s_fc_lock);
@@ -428,7 +429,8 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update) 
	node->fcd_name.len = dentry->d_name.len;



	spin_lock(&sbi->s_fc_lock);

	if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_COMMITTING))

	if (sbi->s_journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||

		sbi->s_journal->j_flags & JBD2_FAST_COMMIT_ONGOING)

		list_add_tail(&node->fcd_list,

				&sbi->s_fc_dentry_q[FC_Q_STAGING]);

	else
@@ -893,7 +895,6 @@ static int ext4_fc_submit_inode_data_all(journal_t *journal) 
	int ret = 0;



	spin_lock(&sbi->s_fc_lock);

	ext4_set_mount_flag(sb, EXT4_MF_FC_COMMITTING);

	list_for_each_entry(ei, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {

		ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING);

		while (atomic_read(&ei->i_fc_updates)) {
@@ -1211,6 +1212,7 @@ static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid) 
		list_del_init(&iter->i_fc_list);

		ext4_clear_inode_state(&iter->vfs_inode,

				       EXT4_STATE_FC_COMMITTING);

		if (iter->i_sync_tid <= tid)

			ext4_fc_reset_inode(&iter->vfs_inode);

		/* Make sure EXT4_STATE_FC_COMMITTING bit is clear */

		smp_mb();
@@ -1240,7 +1242,6 @@ static void ext4_fc_cleanup(journal_t *journal, int full, tid_t tid) 
	list_splice_init(&sbi->s_fc_q[FC_Q_STAGING],

				&sbi->s_fc_q[FC_Q_MAIN]);



	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);

	if (tid >= sbi->s_fc_ineligible_tid) {

		sbi->s_fc_ineligible_tid = 0;

		ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);

fs/ext4/super.c

+0 −1
Original line number Diff line number Diff line
@@ -5083,7 +5083,6 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) 
	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);

	sbi->s_fc_bytes = 0;

	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);

	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);

	sbi->s_fc_ineligible_tid = 0;

	spin_lock_init(&sbi->s_fc_lock);

	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));