Re: [PATCH] btrfs: reject zoned RW mount if sectorsize is smaller than page size

[David Sterba <dsterba@suse.cz>]

On Mon, Feb 12, 2024 at 08:20:21PM +1030, Qu Wenruo wrote:
> 
> 
> On 2024/2/12 20:15, Johannes Thumshirn wrote:
> > On 12.02.24 06:16, Qu Wenruo wrote:
> >> Reported-by: HAN Yuwei <hrx@bupt.moe>
> >> Link: https://lore.kernel.org/all/1ACD2E3643008A17+da260584-2c7f-432a-9e22-9d390aae84cc@bupt.moe/
> >> CC: stable@vger.kernel.org # 5.10+
> >> Signed-off-by: Qu Wenruo <wqu@suse.com>
> >> ---
> >>    fs/btrfs/disk-io.c | 3 ++-
> >>    1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> >> index c3ab268533ca..85cd23aebdd6 100644
> >> --- a/fs/btrfs/disk-io.c
> >> +++ b/fs/btrfs/disk-io.c
> >> @@ -3193,7 +3193,8 @@ int btrfs_check_features(struct btrfs_fs_info *fs_info, bool is_rw_mount)
> >>    	 * part of @locked_page.
> >>    	 * That's also why compression for subpage only work for page aligned ranges.
> >>    	 */
> >> -	if (fs_info->sectorsize < PAGE_SIZE && btrfs_is_zoned(fs_info) && is_rw_mount) {
> >> +	if (fs_info->sectorsize < PAGE_SIZE &&
> >> +	    btrfs_fs_incompat(fs_info, ZONED) && is_rw_mount) {
> >>    		btrfs_warn(fs_info,
> >>    	"no zoned read-write support for page size %lu with sectorsize %u",
> >>    			   PAGE_SIZE, fs_info->sectorsize);
> >
> > Please keep btrfs_is_zoned(fs_info) instead of using
> > btrfs_fs_incompat(fs_info, ZONED).
> 
> At the time of calling, we haven't yet populate fs_info->zone_size, thus
> we have to use super flags to verify if it's zoned.
> 
> If needed, I can add a comment for it.

Yes please add a comment the difference is quite subtle.