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Diffstat (limited to 'fs/btrfs/send.c')
-rw-r--r--fs/btrfs/send.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 145c84b44fd0..1c4b693ee4a3 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -5702,6 +5702,7 @@ static int clone_range(struct send_ctx *sctx, struct btrfs_path *dst_path,
u64 ext_len;
u64 clone_len;
u64 clone_data_offset;
+ bool crossed_src_i_size = false;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(clone_root->root, path);
@@ -5759,8 +5760,10 @@ static int clone_range(struct send_ctx *sctx, struct btrfs_path *dst_path,
if (key.offset >= clone_src_i_size)
break;
- if (key.offset + ext_len > clone_src_i_size)
+ if (key.offset + ext_len > clone_src_i_size) {
ext_len = clone_src_i_size - key.offset;
+ crossed_src_i_size = true;
+ }
clone_data_offset = btrfs_file_extent_offset(leaf, ei);
if (btrfs_file_extent_disk_bytenr(leaf, ei) == disk_byte) {
@@ -5821,6 +5824,25 @@ static int clone_range(struct send_ctx *sctx, struct btrfs_path *dst_path,
ret = send_clone(sctx, offset, clone_len,
clone_root);
}
+ } else if (crossed_src_i_size && clone_len < len) {
+ /*
+ * If we are at i_size of the clone source inode and we
+ * can not clone from it, terminate the loop. This is
+ * to avoid sending two write operations, one with a
+ * length matching clone_len and the final one after
+ * this loop with a length of len - clone_len.
+ *
+ * When using encoded writes (BTRFS_SEND_FLAG_COMPRESSED
+ * was passed to the send ioctl), this helps avoid
+ * sending an encoded write for an offset that is not
+ * sector size aligned, in case the i_size of the source
+ * inode is not sector size aligned. That will make the
+ * receiver fallback to decompression of the data and
+ * writing it using regular buffered IO, therefore while
+ * not incorrect, it's not optimal due decompression and
+ * possible re-compression at the receiver.
+ */
+ break;
} else {
ret = send_extent_data(sctx, dst_path, offset,
clone_len);