Re: [PATCH 4/4] ext3: Warn if mounting rw on a disk requiringstable page writes

From: Jan Kara
Date: Tue Nov 20 2012 - 21:15:47 EST


On Tue 20-11-12 18:00:56, Darrick J. Wong wrote:
> ext3 doesn't properly isolate pages from changes during writeback. Since the
> recommended fix is to use ext4, for now we'll just print a warning if the user
> tries to mount in write mode.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/ext3/super.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
>
> diff --git a/fs/ext3/super.c b/fs/ext3/super.c
> index 5366393..5b3725d 100644
> --- a/fs/ext3/super.c
> +++ b/fs/ext3/super.c
> @@ -1325,6 +1325,14 @@ static int ext3_setup_super(struct super_block *sb, struct ext3_super_block *es,
> "forcing read-only mode");
> res = MS_RDONLY;
> }
> + if (!read_only &&
> + queue_requires_stable_pages(bdev_get_queue(sb->s_bdev))) {
> + ext3_msg(sb, KERN_ERR,
> + "error: ext3 cannot safely write data to a disk "
> + "requiring stable pages writes; forcing read-only "
> + "mode. Upgrading to ext4 is recommended.");
> + res = MS_RDONLY;
> + }
> if (read_only)
> return res;
> if (!(sbi->s_mount_state & EXT3_VALID_FS))
Why this? ext3 should be fixed by your change to
filemap_page_mkwrite()... Or does testing show otherwise?

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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