Btrfs: dev-replace: skip prealloc extents when copy nocow pages

It doens't make sense to process prealloc extents as pages will be
filled with zero when reading prealloc extents.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index beb441d..9fb7d09 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -4480,7 +4480,8 @@ static int check_extent_to_block(struct btrfs_inode *inode, u64 start, u64 len,
         * move on to the next inode.
         */
        if (em->block_start > logical ||
-           em->block_start + em->block_len < logical + len) {
+           em->block_start + em->block_len < logical + len ||
+           test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
                free_extent_map(em);
                ret = 1;
                goto out_unlock;