Re: (2) [PATCH] f2fs: fix null reference error when checking end of zone

[Chao Yu]

On 2024/7/4 15:55, Daejun Park wrote:
> Hi Chao Yu,
> >   
> > --------- Original Message ---------
> > Sender : Chao Yu <chao@xxxxxxxxxx>
> > Date : 2024-07-04 16:16 (GMT+9)
> > Title : Re: [PATCH] f2fs: fix null reference error when checking end of zone
> >   
> > On 2024/7/4 9:01, Daejun Park wrote:
> > > This patch fixes a potentially null pointer being accessed by
> > > is_end_zone_blkaddr() that checks the last block of a zone
> > > when f2fs is mounted as a single device.
> >
> > blkzoned feature depends on multiple device feature? One regular
> > device and one seq-zone device?
>
> According to mkfs.f2fs, if there are a sufficient number of
> conventional zones, a single zoned device can be used.

Correct.

Anyway, the code looks clean.

Reviewed-by: Chao Yu <chao@xxxxxxxxxx>

Thanks,

> Thanks,
> Daejun
>
> > Thanks,
> >
> > > Fixes: e067dc3c6b9c ("f2fs: maintain six open zones for zoned devices")
> > > Signed-off-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
> > > ---
> > >    fs/f2fs/data.c 4 +++-
> > >    1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > > index b6dcb3bcaef7..1aa7eefa659c 100644
> > > --- a/fs/f2fs/data.c
> > > +++ b/fs/f2fs/data.c
> > > @@ -925,6 +925,7 @@ int f2fs_merge_page_bio(struct f2fs_io_info *fio)
> > >    #ifdef CONFIG_BLK_DEV_ZONED
> > >    static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
> > >    {
> > > +        struct block_device *bdev = sbi->sb->s_bdev;
> > >             int devi = 0;
> > >   
> > >             if (f2fs_is_multi_device(sbi)) {
> > > @@ -935,8 +936,9 @@ static bool is_end_zone_blkaddr(struct f2fs_sb_info *sbi, block_t blkaddr)
> > >                             return false;
> > >                     }
> > >                     blkaddr -= FDEV(devi).start_blk;
> > > +                bdev = FDEV(devi).bdev;
> > >             }
> > > -        return bdev_is_zoned(FDEV(devi).bdev) &&
> > > +        return bdev_is_zoned(bdev) &&
> > >                     f2fs_blkz_is_seq(sbi, devi, blkaddr) &&
> > >                     (blkaddr % sbi->blocks_per_blkz == sbi->blocks_per_blkz - 1);
> > >    }