Btrfs: fix send to deal with sparse files properly
Send was just sending everything it found, even if the extent was a hole. This
is unpleasant for users, so just skip holes when we are sending. This will also
skip sending prealloc extents since the send spec doesn't have a prealloc
command. Eventually we will add a prealloc command and rev the send version so
we can send down the prealloc info. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index db7da682..cbe92da 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -3920,7 +3920,8 @@
btrfs_item_key_to_cpu(eb, &found_key, slot);
if (found_key.objectid != key.objectid ||
found_key.type != key.type) {
- ret = 0;
+ /* If we're a hole then just pretend nothing changed */
+ ret = (left_disknr) ? 0 : 1;
goto out;
}
@@ -3946,7 +3947,8 @@
* This may only happen on the first iteration.
*/
if (found_key.offset + right_len <= ekey->offset) {
- ret = 0;
+ /* If we're a hole just pretend nothing changed */
+ ret = (left_disknr) ? 0 : 1;
goto out;
}
@@ -4011,8 +4013,8 @@
struct btrfs_path *path,
struct btrfs_key *key)
{
- int ret = 0;
struct clone_root *found_clone = NULL;
+ int ret = 0;
if (S_ISLNK(sctx->cur_inode_mode))
return 0;
@@ -4025,6 +4027,32 @@
ret = 0;
goto out;
}
+ } else {
+ struct btrfs_file_extent_item *ei;
+ u8 type;
+
+ ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_file_extent_item);
+ type = btrfs_file_extent_type(path->nodes[0], ei);
+ if (type == BTRFS_FILE_EXTENT_PREALLOC ||
+ type == BTRFS_FILE_EXTENT_REG) {
+ /*
+ * The send spec does not have a prealloc command yet,
+ * so just leave a hole for prealloc'ed extents until
+ * we have enough commands queued up to justify rev'ing
+ * the send spec.
+ */
+ if (type == BTRFS_FILE_EXTENT_PREALLOC) {
+ ret = 0;
+ goto out;
+ }
+
+ /* Have a hole, just skip it. */
+ if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0) {
+ ret = 0;
+ goto out;
+ }
+ }
}
ret = find_extent_clone(sctx, path, key->objectid, key->offset,