Commit 3df32196 authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Jan Kara
Browse files

ext3: Fix fsync error handling after filesystem abort. 

If filesystem was aborted we will return success
due to (sb->s_flags & MS_RDONLY) which is incorrect and
results in data loss.
In order to handle fs abort correctly we have to check
fs state once we discover that it is in MS_RDONLY state

Test case: http://patchwork.ozlabs.org/patch/244297/


Changes from V1:
 - fix spelling
 - fix smp_rmb()/debug order

Signed-off-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent a1457c0c

fs/ext3/fsync.c

+6 −2
Original line number Diff line number Diff line
@@ -48,9 +48,13 @@ int ext3_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 


	trace_ext3_sync_file_enter(file, datasync);



	if (inode->i_sb->s_flags & MS_RDONLY)

	if (inode->i_sb->s_flags & MS_RDONLY) {

		/* Make sure that we read updated state */

		smp_rmb();

		if (EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS)

			return -EROFS;

		return 0;



	}

	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);

	if (ret)

		goto out;

fs/ext3/super.c

+12 −1
Original line number Diff line number Diff line
@@ -174,6 +174,11 @@ static void ext3_handle_error(struct super_block *sb) 
	if (test_opt (sb, ERRORS_RO)) {

		ext3_msg(sb, KERN_CRIT,

			"error: remounting filesystem read-only");

		/*

		 * Make sure updated value of ->s_mount_state will be visible

		 * before ->s_flags update.

		 */

		smp_wmb();

		sb->s_flags |= MS_RDONLY;

	}

	ext3_commit_super(sb, es, 1);
@@ -291,8 +296,14 @@ void ext3_abort(struct super_block *sb, const char *function, 
	ext3_msg(sb, KERN_CRIT,

		"error: remounting filesystem read-only");

	EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;

	sb->s_flags |= MS_RDONLY;

	set_opt(EXT3_SB(sb)->s_mount_opt, ABORT);

	/*

	 * Make sure updated value of ->s_mount_state will be visible

	 * before ->s_flags update.

	 */

	smp_wmb();

	sb->s_flags |= MS_RDONLY;



	if (EXT3_SB(sb)->s_journal)

		journal_abort(EXT3_SB(sb)->s_journal, -EIO);

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE