Filipe David Borba Manana
2014-May-25 02:43 UTC
[PATCH] Btrfs: send, don't error in the presence of subvols/snapshots
If we are doing an incremental send and the base snapshot has a directory with name X that doesn't exist anymore in the second snapshot and a new subvolume/snapshot exists in the second snapshot that has the same name as the directory (name X), the incremental send would fail with -ENOENT error. This is because it attempts to lookup for an inode with a number matching the objectid of a root, which doesn't exist. Steps to reproduce: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt mkdir /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap1 rmdir /mnt/testdir btrfs subvolume create /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap2 btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data A test case for xfstests follows. Reported-by: Robert White <rwhite@pobox.com> Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> --- fs/btrfs/send.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 1a65a40..f51525e 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -1642,7 +1642,8 @@ out: static int lookup_dir_item_inode(struct btrfs_root *root, u64 dir, const char *name, int name_len, u64 *found_inode, - u8 *found_type) + u8 *found_type, + int *found_is_root) { int ret = 0; struct btrfs_dir_item *di; @@ -1666,6 +1667,8 @@ static int lookup_dir_item_inode(struct btrfs_root *root, btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key); *found_inode = key.objectid; *found_type = btrfs_dir_type(path->nodes[0], di); + if (found_is_root) + *found_is_root = (key.type == BTRFS_ROOT_ITEM_KEY); out: btrfs_free_path(path); @@ -1816,7 +1819,7 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen, } ret = lookup_dir_item_inode(sctx->parent_root, dir, name, name_len, - &other_inode, &other_type); + &other_inode, &other_type, NULL); if (ret < 0 && ret != -ENOENT) goto out; if (ret) { @@ -1861,6 +1864,7 @@ static int did_overwrite_ref(struct send_ctx *sctx, u64 gen; u64 ow_inode; u8 other_type; + int other_is_root = 0; if (!sctx->parent_root) goto out; @@ -1871,10 +1875,10 @@ static int did_overwrite_ref(struct send_ctx *sctx, /* check if the ref was overwritten by another ref */ ret = lookup_dir_item_inode(sctx->send_root, dir, name, name_len, - &ow_inode, &other_type); + &ow_inode, &other_type, &other_is_root); if (ret < 0 && ret != -ENOENT) goto out; - if (ret) { + if (ret || other_is_root) { /* was never and will never be overwritten */ ret = 0; goto out; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html