On Wed, Apr 14, 2021 at 03:47:08PM +0200, Karel Zak wrote:
> On Wed, Apr 14, 2021 at 10:33:38AM +0900, Naohiro Aota wrote:
> > +#define ASSERT(x) assert(x)
>
> Really? ;-)
>
> > +typedef uint64_t u64;
> > +typedef uint64_t sector_t;
> > +typedef uint8_t u8;
>
> I do not see a reason for u64 and u8 here.
Yep, these are here just to make it easy to copy the code from
kernel. But this code won't change so much, so I can drop these.
> > +
> > +#ifdef HAVE_LINUX_BLKZONED_H
> > +static int sb_write_pointer(int fd, struct blk_zone *zones, u64 *wp_ret)
> > +{
> > + bool empty[BTRFS_NR_SB_LOG_ZONES];
> > + bool full[BTRFS_NR_SB_LOG_ZONES];
> > + sector_t sector;
> > +
> > + ASSERT(zones[0].type != BLK_ZONE_TYPE_CONVENTIONAL &&
> > + zones[1].type != BLK_ZONE_TYPE_CONVENTIONAL);
>
> assert()
I will use it.
> ...
> > + for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
> > + u64 bytenr;
> > +
> > + bytenr = ((zones[i].start + zones[i].len)
> > + << SECTOR_SHIFT) - BTRFS_SUPER_INFO_SIZE;
> > +
> > + ret = pread64(fd, buf[i], BTRFS_SUPER_INFO_SIZE,
> > + bytenr);
>
> please, use
>
> ptr = blkid_probe_get_buffer(pr, BTRFS_SUPER_INFO_SIZE, bytenr);
>
> the library will care about the buffer and reuse it. It's also
> important to keep blkid_do_wipe() usable.
Sure. I'll use it.
> > + if (ret != BTRFS_SUPER_INFO_SIZE)
> > + return -EIO;
> > + super[i] = (struct btrfs_super_block *)&buf[i];
>
> super[i] = (struct btrfs_super_block *) ptr;
>
> > + }
> > +
> > + if (super[0]->generation > super[1]->generation)
> > + sector = zones[1].start;
> > + else
> > + sector = zones[0].start;
> > + } else if (!full[0] && (empty[1] || full[1])) {
> > + sector = zones[0].wp;
> > + } else if (full[0]) {
> > + sector = zones[1].wp;
> > + } else {
> > + return -EUCLEAN;
> > + }
> > + *wp_ret = sector << SECTOR_SHIFT;
> > + return 0;
> > +}
> > +
> > +static int sb_log_offset(blkid_probe pr, uint64_t *bytenr_ret)
> > +{
> > + uint32_t zone_num = 0;
> > + uint32_t zone_size_sector;
> > + struct blk_zone_report *rep;
> > + struct blk_zone *zones;
> > + size_t rep_size;
> > + int ret;
> > + uint64_t wp;
> > +
> > + zone_size_sector = pr->zone_size >> SECTOR_SHIFT;
> > +
> > + rep_size = sizeof(struct blk_zone_report) + sizeof(struct blk_zone) * 2;
> > + rep = malloc(rep_size);
> > + if (!rep)
> > + return -errno;
> > +
> > + memset(rep, 0, rep_size);
> > + rep->sector = zone_num * zone_size_sector;
> > + rep->nr_zones = 2;
>
> what about to add to lib/blkdev.c a new function:
>
> struct blk_zone_report *blkdev_get_zonereport(int fd, uint64 sector, int
> nzones);
>
> and call this function from your sb_log_offset() as well as from
> blkid_do_wipe()?
>
> Anyway, calloc() is better than malloc()+memset().
Indeed. I will do so.
> > + if (zones[0].type == BLK_ZONE_TYPE_CONVENTIONAL) {
> > + *bytenr_ret = zones[0].start << SECTOR_SHIFT;
> > + ret = 0;
> > + goto out;
> > + } else if (zones[1].type == BLK_ZONE_TYPE_CONVENTIONAL) {
> > + *bytenr_ret = zones[1].start << SECTOR_SHIFT;
> > + ret = 0;
> > + goto out;
> > + }
>
> what about:
>
> for (i = 0; i < BTRFS_NR_SB_LOG_ZONES; i++) {
> if (zones[i].type == BLK_ZONE_TYPE_CONVENTIONAL) {
> *bytenr_ret = zones[i].start << SECTOR_SHIFT;
> ret = 0;
> goto out;
> }
> }
Yes, this looks cleaner. Thanks.
>
>
>
> Karel
>
> --
> Karel Zak <k...@redhat.com>
> http://karelzak.blogspot.com
>
