Re: [PATCH 1/1]ext4: Fix WARN_ON_ONCE when marking buffer dirty

[Pranay Srivastava]

On Thu, Jun 30, 2016 at 4:42 PM, Pranay Kr. Srivastava
<pranjas@xxxxxxxxx> wrote:
> Signed-off-by: Pranay Kr. Srivastava <pranjas@xxxxxxxxx>
> ---
>  fs/ext4/super.c | 30 ++++++++++++++++--------------
>  1 file changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 3822a5a..8f10715 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4327,20 +4327,6 @@ static int ext4_commit_super(struct super_block *sb, int sync)
>
>         if (!sbh || block_device_ejected(sb))
>                 return error;
> -       if (buffer_write_io_error(sbh)) {
> -               /*
> -                * Oh, dear.  A previous attempt to write the
> -                * superblock failed.  This could happen because the
> -                * USB device was yanked out.  Or it could happen to
> -                * be a transient write error and maybe the block will
> -                * be remapped.  Nothing we can do but to retry the
> -                * write and hope for the best.
> -                */
> -               ext4_msg(sb, KERN_ERR, "previous I/O error to "
> -                      "superblock detected");
> -               clear_buffer_write_io_error(sbh);
> -               set_buffer_uptodate(sbh);
> -       }
>         /*
>          * If the file system is mounted read-only, don't update the
>          * superblock write time.  This avoids updating the superblock
> @@ -4371,7 +4357,23 @@ static int ext4_commit_super(struct super_block *sb, int sync)
>                                 &EXT4_SB(sb)->s_freeinodes_counter));
>         BUFFER_TRACE(sbh, "marking dirty");
>         ext4_superblock_csum_set(sb);
> +       lock_buffer(sbh);
> +       if (buffer_write_io_error(sbh)) {
> +               /*
> +                * Oh, dear.  A previous attempt to write the
> +                * superblock failed.  This could happen because the
> +                * USB device was yanked out.  Or it could happen to
> +                * be a transient write error and maybe the block will
> +                * be remapped.  Nothing we can do but to retry the
> +                * write and hope for the best.
> +                */
> +               ext4_msg(sb, KERN_ERR, "previous I/O error to "
> +                      "superblock detected");
> +               clear_buffer_write_io_error(sbh);
> +               set_buffer_uptodate(sbh);
> +       }
>         mark_buffer_dirty(sbh);
> +       unlock_buffer(sbh);
>         if (sync) {
>                 error = __sync_dirty_buffer(sbh,
>                         test_opt(sb, BARRIER) ? WRITE_FUA : WRITE_SYNC);
> --
> 1.9.1
>

Can this be reviewed as well please.


-- 
        ---P.K.S