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Commit 06a407f1 authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Theodore Ts'o
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ext4: fix data integrity for ext4_sync_fs 



Inode's data or non journaled quota may be written w/o jounral so we
_must_ send a barrier at the end of ext4_sync_fs. But it can be
skipped if journal commit will do it for us.

Also fix data integrity for nojournal mode.

Signed-off-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 9ff86446

fs/ext4/super.c

+35 −1
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ static void ext4_mark_recovery_complete(struct super_block *sb, 
static void ext4_clear_journal_err(struct super_block *sb,

				   struct ext4_super_block *es);

static int ext4_sync_fs(struct super_block *sb, int wait);

static int ext4_sync_fs_nojournal(struct super_block *sb, int wait);

static int ext4_remount(struct super_block *sb, int *flags, char *data);

static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);

static int ext4_unfreeze(struct super_block *sb);
@@ -1097,6 +1098,7 @@ static const struct super_operations ext4_nojournal_sops = { 
	.dirty_inode	= ext4_dirty_inode,

	.drop_inode	= ext4_drop_inode,

	.evict_inode	= ext4_evict_inode,

	.sync_fs	= ext4_sync_fs_nojournal,

	.put_super	= ext4_put_super,

	.statfs		= ext4_statfs,

	.remount_fs	= ext4_remount,
@@ -4553,6 +4555,7 @@ static int ext4_sync_fs(struct super_block *sb, int wait) 
{

	int ret = 0;

	tid_t target;

	bool needs_barrier = false;

	struct ext4_sb_info *sbi = EXT4_SB(sb);



	trace_ext4_sync_fs(sb, wait);
@@ -4563,10 +4566,41 @@ static int ext4_sync_fs(struct super_block *sb, int wait) 
	 * no dirty dquots

	 */

	dquot_writeback_dquots(sb, -1);

	/*

	 * Data writeback is possible w/o journal transaction, so barrier must

	 * being sent at the end of the function. But we can skip it if

	 * transaction_commit will do it for us.

	 */

	target = jbd2_get_latest_transaction(sbi->s_journal);

	if (wait && sbi->s_journal->j_flags & JBD2_BARRIER &&

	    !jbd2_trans_will_send_data_barrier(sbi->s_journal, target))

		needs_barrier = true;



	if (jbd2_journal_start_commit(sbi->s_journal, &target)) {

		if (wait)

			jbd2_log_wait_commit(sbi->s_journal, target);

			ret = jbd2_log_wait_commit(sbi->s_journal, target);

	}

	if (needs_barrier) {

		int err;

		err = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);

		if (!ret)

			ret = err;

	}



	return ret;

}



static int ext4_sync_fs_nojournal(struct super_block *sb, int wait)

{

	int ret = 0;



	trace_ext4_sync_fs(sb, wait);

	flush_workqueue(EXT4_SB(sb)->rsv_conversion_wq);

	flush_workqueue(EXT4_SB(sb)->unrsv_conversion_wq);

	dquot_writeback_dquots(sb, -1);

	if (wait && test_opt(sb, BARRIER))

		ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);



	return ret;

}

include/linux/jbd2.h

+13 −0
Original line number Diff line number Diff line
@@ -1374,6 +1374,19 @@ static inline u32 jbd2_chksum(journal_t *journal, u32 crc, 
	return *(u32 *)desc.ctx;

}



/* Return most recent uncommitted transaction */

static inline tid_t  jbd2_get_latest_transaction(journal_t *journal)

{

	tid_t tid;



	read_lock(&journal->j_state_lock);

	tid = journal->j_commit_request;

	if (journal->j_running_transaction)

		tid = journal->j_running_transaction->t_tid;

	read_unlock(&journal->j_state_lock);

	return tid;

}



#ifdef __KERNEL__



#define buffer_trace_init(bh)	do {} while (0)