From 57cfd4627046efc43081d26b5db77dbfb7595caa Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 20 Aug 2013 15:55:39 -0400 Subject: [PATCH] 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 Signed-off-by: Chris Mason --- fs/btrfs/send.c | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index db7da682f0d2..cbe92da5f33b 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -3920,7 +3920,8 @@ static int is_extent_unchanged(struct send_ctx *sctx, 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 @@ static int is_extent_unchanged(struct send_ctx *sctx, * 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 @@ static int process_extent(struct send_ctx *sctx, 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 @@ static int process_extent(struct send_ctx *sctx, 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, -- 2.20.1