On Tue 30-05-17 11:50:36, Jeff Layton wrote:
> sync_filesystem is called from several kernel subsystems to write out
> a superblock. After writing out the inodes, it calls the superblock
> sync_fs operation, which is an int return operation. That error code
> is then discarded. It then calls __sync_blockdev and returns an error
> if that fails.
>
> Most filesystems that have a sync_fs operation do most of the work
> inside that operation and then return an error if it fails. With those
> filesystems, the sync_blockdev is effectively a no-op and may very well
> not return an error even though writeback failed.
>
> Have __sync_filesystem preserve the error from sync_fs and return that
> if it fails, or the return from __sync_blockdev if it succeeds.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Makes sense. Although this will likely have only a small impact since most
of the errors are likely to happen in the inode writeback where they just
get ignored. Anyway you can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/sync.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/fs/sync.c b/fs/sync.c
> index 45ecf6854595..ec93aac4feb9 100644
> --- a/fs/sync.c
> +++ b/fs/sync.c
> @@ -29,14 +29,18 @@
> */
> static int __sync_filesystem(struct super_block *sb, int wait)
> {
> + int fs_ret = 0, bd_ret;
> +
> if (wait)
> sync_inodes_sb(sb);
> else
> writeback_inodes_sb(sb, WB_REASON_SYNC);
>
> if (sb->s_op->sync_fs)
> - sb->s_op->sync_fs(sb, wait);
> - return __sync_blockdev(sb->s_bdev, wait);
> + fs_ret = sb->s_op->sync_fs(sb, wait);
> + bd_ret = __sync_blockdev(sb->s_bdev, wait);
> +
> + return fs_ret ? fs_ret : bd_ret;
> }
>
> /*
> --
> 2.9.4
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
