Hi Jan, Thank you for the review.
On 04/19, Jan Kara wrote: > On Thu 29-03-18 18:44:29, Jaegeuk Kim wrote: > > From: Jaegeuk Kim <[email protected]> > > > > 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" <[email protected]> > > Cc: Andreas Dilger <[email protected]> > > Cc: [email protected] > > Cc: Jaegeuk Kim <[email protected]> > > Signed-off-by: Jaegeuk Kim <[email protected]> > > --- > > 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 Indeed. I'll update it in v2. > up before making ext4_setup_super() return error code (as your patch could > make ext4_fill_super() return SB_RDONLY under some circumstances). Interestingly, it only affects ext4_remount() only. :P > > > @@ -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; Got it. Thanks, > > Honza > -- > Jan Kara <[email protected]> > SUSE Labs, CR
