Re: [f2fs-dev] [PATCH v3] f2fs: fix zoned block device information initialization

[Wenjie Qi]

Hi all,

Yes, I also agree with using bdev_max_open_zones() instead of
bdev_max_active_zones().
I will submit a revised version as soon as possible.

Thanks,

On Thu, Feb 1, 2024 at 10:47 PM Chao Yu <chao@xxxxxxxxxx> wrote:
>
> On 2024/1/23 17:18, Yongpeng Yang wrote:
> > Hi Wenjie,
> > It seems more reasonable to use bdev_max_open_zones instead of
> > bdev_max_active_zones.
>
> Hi all,
>
> I guess it needs to be initialized w/ bdev_max_open_zones(), due
> to the max of open zones of zoned device limits the number of
> zones that a host software can simultaneously write [1], right?
>
> [1] https://zonedstorage.io/docs/introduction/zoned-storage#active-zones-limit
>
> Thanks,
>
> >
> > If an NVMe device has multiple namespaces, and the device contains a
> > total of 11 open zones, two of the namespaces, nvme0n1 and nvme0n2, each
> > correspond to an instance of the F2FS filesystem, and both filesystem
> > instances can be initialized successfully. Since multiple namespaces
> > share all open zones, the number of open zones is not equal to the
> > number of open zones available to F2FS in a multi-namespace scenario.
> > This patch does not yet cover this scenario.
> >
> > On 1/23/2024 4:12 PM, Wenjie Qi wrote:
> >> If the max active 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 | 18 ++++++++++++++++++
> >>    2 files changed, 19 insertions(+)
> >>
> >> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >> index 65294e3b0bef..669f84f6b0e5 100644
> >> --- a/fs/f2fs/f2fs.h
> >> +++ b/fs/f2fs/f2fs.h
> >> @@ -1551,6 +1551,7 @@ struct f2fs_sb_info {
> >>
> >>    #ifdef CONFIG_BLK_DEV_ZONED
> >>      unsigned int blocks_per_blkz;           /* F2FS blocks per zone */
> >> +    unsigned int max_active_zones;          /* max zone resources of the zoned device */
> >>    #endif
> >>
> >>      /* for node-related operations */
> >> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >> index 206d03c82d96..aef41b54098c 100644
> >> --- a/fs/f2fs/super.c
> >> +++ b/fs/f2fs/super.c
> >> @@ -2385,6 +2385,16 @@ 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_active_zones && sbi->max_active_zones < F2FS_OPTION(sbi).active_logs) {
> >> +            f2fs_err(sbi,
> >> +                    "zoned: max active zones %u is too small, need at least %u active zones",
> >> +                             sbi->max_active_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);
> >>
> >> @@ -3932,6 +3942,14 @@ static int init_blkz_info(struct f2fs_sb_info *sbi, int devi)
> >>      if (!f2fs_sb_has_blkzoned(sbi))
> >>              return 0;
> >>
> >> +    sbi->max_active_zones = bdev_max_active_zones(bdev);
> >> +    if (sbi->max_active_zones && sbi->max_active_zones < F2FS_OPTION(sbi).active_logs) {
> >> +            f2fs_err(sbi,
> >> +                    "zoned: max active zones %u is too small, need at least %u active zones",
> >> +                             sbi->max_active_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");