On Thu 29-03-18 18:44:29, Jaegeuk Kim wrote:
> From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
>
> When remounting ext4 from ro to rw, currently it allows its transition,
> even if ext4_commit_super() returns EIO. Even worse thing is, after that,
> fs/buffer complains buffer dirty bits like:
>
> Call trace:
> [<ffffff9750c259dc>] mark_buffer_dirty+0x184/0x1a4
> [<ffffff9750cb398c>] __ext4_handle_dirty_super+0x4c/0xfc
> [<ffffff9750c7a9fc>] ext4_file_open+0x154/0x1c0
> [<ffffff9750bea51c>] do_dentry_open+0x114/0x2d0
> [<ffffff9750bea75c>] vfs_open+0x5c/0x94
> [<ffffff9750bf879c>] path_openat+0x668/0xfe8
> [<ffffff9750bf8088>] do_filp_open+0x74/0x120
> [<ffffff9750beac98>] do_sys_open+0x148/0x254
> [<ffffff9750beade0>] SyS_openat+0x10/0x18
> [<ffffff9750a83ab0>] el0_svc_naked+0x24/0x28
> EXT4-fs (dm-1): previous I/O error to superblock detected
> Buffer I/O error on dev dm-1, logical block 0, lost sync page write
> EXT4-fs (dm-1): re-mounted. Opts: (null)
> Buffer I/O error on dev dm-1, logical block 80, lost async page write
>
> Cc: "Theodore Ts'o" <tytso@xxxxxxx>
> Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
> Cc: linux-ext4@xxxxxxxxxxxxxxx
> Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> fs/ext4/super.c | 21 +++++++++++++--------
> 1 file changed, 13 insertions(+), 8 deletions(-)
Thanks for the patch. Some comments below.
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 39bf464c35f1..b268bfea879c 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -2151,7 +2151,7 @@ static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
> if (sbi->s_journal)
> ext4_set_feature_journal_needs_recovery(sb);
>
> - ext4_commit_super(sb, 1);
> + res = ext4_commit_super(sb, 1);
> done:
> if (test_opt(sb, DEBUG))
> printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
So return value of ext4_setup_super() looks a bit strange and it seems it
currently returns 0 or SB_RDONLY. So I think you first need to clean this
up before making ext4_setup_super() return error code (as your patch could
make ext4_fill_super() return SB_RDONLY under some circumstances).
> @@ -4739,11 +4739,10 @@ static int ext4_commit_super(struct super_block *sb, int sync)
> unlock_buffer(sbh);
> error = __sync_dirty_buffer(sbh,
> REQ_SYNC | (test_opt(sb, BARRIER) ? REQ_FUA : 0));
> - if (error)
> + if (error && !buffer_write_io_error(sbh))
> return error;
>
> - error = buffer_write_io_error(sbh);
> - if (error) {
> + if (buffer_write_io_error(sbh)) {
> ext4_msg(sb, KERN_ERR, "I/O error while writing "
> "superblock");
> clear_buffer_write_io_error(sbh);
I'd rather rewrite this as:
if (buffer_write_io_error(sbh)) {
do stuff as now
}
if (error)
return error;
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
