btrfs: raid56: enable subpage support for RAID56

Now the btrfs RAID56 infrastructure has migrated to use sector_ptr
interface, it should be safe to enable subpage support for RAID56.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -3686,14 +3686,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 		btrfs_warn(fs_info,
 		"read-write for sector size %u with page size %lu is experimental",
 			   sectorsize, PAGE_SIZE);
-		if (btrfs_super_incompat_flags(fs_info->super_copy) &
-			BTRFS_FEATURE_INCOMPAT_RAID56) {
-			btrfs_err(fs_info,
-		"RAID56 is not yet supported for sector size %u with page size %lu",
-				sectorsize, PAGE_SIZE);
-			err = -EINVAL;
-			goto fail_alloc;
-		}
 		subpage_info = kzalloc(sizeof(*subpage_info), GFP_KERNEL);
 		if (!subpage_info)
 			goto fail_alloc;

fs/btrfs/raid56.c

@@ -1154,9 +1154,6 @@ static int rbio_add_io_sector(struct btrfs_raid_bio *rbio,
 	ASSERT(sector_nr >= 0 && sector_nr < rbio->stripe_nsectors);
 	ASSERT(sector->page);
 
-	/* We don't yet support subpage, thus pgoff should always be 0 */
-	ASSERT(sector->pgoff == 0);
-
 	stripe = &rbio->bioc->stripes[stripe_nr];
 	disk_start = stripe->physical + sector_nr * sectorsize;
 
@@ -2378,9 +2375,6 @@ struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
 	}
 	ASSERT(i < rbio->real_stripes);
 
-	/* Now we just support the sectorsize equals to page size */
-	ASSERT(fs_info->sectorsize == PAGE_SIZE);
-	ASSERT(rbio->stripe_npages == stripe_nsectors);
 	bitmap_copy(rbio->dbitmap, dbitmap, stripe_nsectors);
 
 	/*

fs/btrfs/volumes.c

@@ -4063,13 +4063,6 @@ static inline int validate_convert_profile(struct btrfs_fs_info *fs_info,
 	if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT))
 		return true;
 
-	if (fs_info->sectorsize < PAGE_SIZE &&
-		bargs->target & BTRFS_BLOCK_GROUP_RAID56_MASK) {
-		btrfs_err(fs_info,
-		"RAID56 is not yet supported for sectorsize %u with page size %lu",
-			  fs_info->sectorsize, PAGE_SIZE);
-		return false;
-	}
 	/* Profile is valid and does not have bits outside of the allowed set */
 	if (alloc_profile_is_valid(bargs->target, 1) &&
 	    (bargs->target & ~allowed) == 0)