On 29.06.20 г. 17:16 ч., Nikolay Borisov wrote: > Since btrfs_bio always contains the extra space for the tgtdev_map and > raid_maps it's pointless to make the assignment iff specific conditions > are met. Instead, always assign the pointers to their correct value at > allocation time. > > Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx> > --- > fs/btrfs/volumes.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index cb9883c7f8b7..1b1fc1485a41 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -5522,6 +5522,9 @@ static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes) > atomic_set(&bbio->error, 0); > refcount_set(&bbio->refs, 1); > > + bbio->tgtdev_map = (int *)(bbio->stripes + total_stripes); > + bbio->raid_map = (u64 *)(bbio->tgtdev_map + real_stripes); > + > return bbio; > } > > @@ -6144,8 +6147,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > ret = -ENOMEM; > goto out; > } > - if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL) > - bbio->tgtdev_map = (int *)(bbio->stripes + num_alloc_stripes); > > /* build raid_map */ > if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && need_raid_map && > @@ -6153,10 +6154,6 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, > u64 tmp; > unsigned rot; > > - bbio->raid_map = (u64 *)((void *)bbio->stripes + > - sizeof(struct btrfs_bio_stripe) * > - num_alloc_stripes + > - sizeof(int) * tgtdev_indexes); > > /* Work out the disk rotation on this stripe-set */ > div_u64_rem(stripe_nr, num_stripes, &rot); > This patch is not complete since the presence of raid_map now means that the sort parityu function in __btrfs_map_block will always be invoked, which is not what we want. I'll send a fixed v2 later.
