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

[Wenjie Qi]

I agree with you, it looks a bit more intuitive that way.
I'll submit a new version of the patch as soon as I can.
Thanks,

On Sun, Feb 4, 2024 at 10:24 AM Chao Yu <chao@xxxxxxxxxx> wrote:
>
> On 2024/2/4 10:18, Wenjie Qi wrote:
> > 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.
>
> Yes, but I'm curious about how this case (sbi->max_open_zones is zero)
> works w/ following patch, do we need to initialized sbi->max_open_zones
> w/ UINT_MAX to indicate the unlimited open zone status of device if
> all zoned devices' max_open_zones is zero?
>
> >
> > 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");