Re: [PATCH v4] f2fs: fix zoned block device information initialization

[Wenjie Qi]

Hi Chao,

It seems to me that when mounting multiple zoned devices,
if their max_open_zones are all 0, then sbi->max_open_zones is 0.
This suggests that all of the mounted devices can open an unlimited
number of zones,
and that we don't need to compare sbi->max_open_zones with
F2FS_OPTION( sbi).active_logs.

Thanks,

Chao Yu <chao@xxxxxxxxxx> 于2024年2月4日周日 09:47写道：
>
> On 2024/2/3 23:24, Wenjie Qi wrote:
> > If the max open zones of zoned devices are less than
> > the active logs of F2FS, the device may error due to
> > insufficient zone resources when multiple active logs are
> > being written at the same time. If this value is 0,
> > there is no limit.
> >
> > Signed-off-by: Wenjie Qi <qwjhust@xxxxxxxxx>
> > ---
> >   fs/f2fs/f2fs.h  |  1 +
> >   fs/f2fs/super.c | 21 +++++++++++++++++++++
> >   2 files changed, 22 insertions(+)
> >
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 543898482f8b..161107f2d3bd 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -1558,6 +1558,7 @@ struct f2fs_sb_info {
> >
> >   #ifdef CONFIG_BLK_DEV_ZONED
> >       unsigned int blocks_per_blkz;           /* F2FS blocks per zone */
> > +     unsigned int max_open_zones;            /* max open zone resources of the zoned device */
> >   #endif
> >
> >       /* for node-related operations */
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index 1b718bebfaa1..45e82d6016fc 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -2388,6 +2388,16 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >       if (err)
> >               goto restore_opts;
> >
> > +#ifdef CONFIG_BLK_DEV_ZONED
> > +     if (sbi->max_open_zones && sbi->max_open_zones < F2FS_OPTION(sbi)active_logs) {
> > +             f2fs_err(sbi,
> > +                     "zoned: max open zones %u is too small, need at least %u open zones",
> > +                              sbi->max_open_zones, F2FS_OPTION(sbi).active_logs);
> > +             err = -EINVAL;
> > +             goto restore_opts;
> > +     }
> > +#endif
> > +
> >       /* flush outstanding errors before changing fs state */
> >       flush_work(&sbi->s_error_work);
> >
> > @@ -3930,11 +3940,22 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
> >       sector_t nr_sectors = bdev_nr_sectors(bdev);
> >       struct f2fs_report_zones_args rep_zone_arg;
> >       u64 zone_sectors;
> > +     unsigned int max_open_zones;
> >       int ret;
> >
> >       if (!f2fs_sb_has_blkzoned(sbi))
> >               return 0;
> >
> > +     max_open_zones = bdev_max_open_zones(bdev);
>
> Wenjie,
>
> max_open_zones can always be zero? then sbi->max_open_zones will be zero,
> is this a valid case?
>
> Thanks,
>
> > +     if (max_open_zones && (max_open_zones < sbi->max_open_zones || !sbi->max_open_zones))
> > +             sbi->max_open_zones = max_open_zones;
> > +     if (sbi->max_open_zones && sbi->max_open_zones < F2FS_OPTION(sbi)active_logs) {
> > +             f2fs_err(sbi,
> > +                     "zoned: max open zones %u is too small, need at least %u open zones",
> > +                              sbi->max_open_zones, F2FS_OPTION(sbi).active_logs);
> > +             return -EINVAL;
> > +     }
> > +
> >       zone_sectors = bdev_zone_sectors(bdev);
> >       if (!is_power_of_2(zone_sectors)) {
> >               f2fs_err(sbi, "F2FS does not support non power of 2 zone sizes\n");