From 64edc851da59c47b92ee6830101be0854add7f09 Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Fri, 1 Feb 2013 15:56:29 +0800 Subject: Btrfs-progs: filter the deleted subvolumes when listing snapshots btrfs snapshot list command will stop by the deleted subvolumes. The problem may happen by two ways: 1. a subvolume deletion is not commited, that is ROOT_BACKREF has been deleted, but ROOT_ITEM still exists. The command will fail to fill the path of the deleted subvolumes because we can not get the parent fs/file tree. 2. a subvolume is possibly deleted when we fill the path, For example, Fs tree |->subv0 |->subv1 We may fill the path of subv1 firstly, after that, some user deletes subv1 and subv0, and then we fill the path of subv0. The command will fail to fill the path of subv0 because we can not get path of subv0. And the command also will fail to make the full path of subv1 because we don't have the path of subv0. Since these subvolumes have been deleted, we should filter them. This patch fixed the above problem by this way. For the 1st case, ->ref_tree of the deleted subvolumes are 0. For the 2nd case, if we found the error number that ioctl() returns is ENOENT, we will set ->ref_tree to 0. And when we make the full path of the subvolumes, we will check ->ref_tree of them and their parent. If someone's ->ref_tree or its parent's ->ref_tree is 0, we will filter it. Reported-by: Stefan Priebe Signed-off-by: Wang Shilong Signed-off-by: Anand Jain --- btrfs-list.c | 42 ++++++++++++++++++++++++++++++++---------- 1 file changed, 32 insertions(+), 10 deletions(-) diff --git a/btrfs-list.c b/btrfs-list.c index 2378a4f8..cfe62f3f 100644 --- a/btrfs-list.c +++ b/btrfs-list.c @@ -564,6 +564,12 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri, while (1) { char *tmp; u64 next; + /* + * ref_tree = 0 indicates the subvolumes + * has been deleted. + */ + if (!found->ref_tree) + return -ENOENT; int add_len = strlen(found->path); /* room for / and for null */ @@ -592,20 +598,22 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri, break; } + /* + * if the ref_tree = BTRFS_FS_TREE_OBJECTID, + * we are at the top + */ if (next == BTRFS_FS_TREE_OBJECTID) { ri->top_id = next; break; } /* - * if the ref_tree wasn't in our tree of roots, we're - * at the top - */ + * if the ref_tree wasn't in our tree of roots, the + * subvolume was deleted. + */ found = root_tree_search(rl, next); - if (!found) { - ri->top_id = next; - break; - } + if (!found) + return -ENOENT; } ri->full_path = full_path; @@ -628,6 +636,9 @@ static int lookup_ino_path(int fd, struct root_info *ri) if (ri->path) return 0; + if (!ri->ref_tree) + return -ENOENT; + memset(&args, 0, sizeof(args)); args.treeid = ri->ref_tree; args.objectid = ri->dir_id; @@ -635,6 +646,10 @@ static int lookup_ino_path(int fd, struct root_info *ri) ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args); e = errno; if (ret) { + if (e == ENOENT) { + ri->ref_tree = 0; + return -ENOENT; + } fprintf(stderr, "ERROR: Failed to lookup path for root %llu - %s\n", (unsigned long long)ri->ref_tree, strerror(e)); @@ -1268,10 +1283,13 @@ static void __filter_and_sort_subvol(struct root_lookup *all_subvols, while (n) { entry = rb_entry(n, struct root_info, rb_node); - resolve_root(all_subvols, entry, top_id); + ret = resolve_root(all_subvols, entry, top_id); + if (ret == -ENOENT) + goto skip; ret = filter_root(entry, filter_set); if (ret) sort_tree_insert(sort_tree, entry, comp_set); +skip: n = rb_prev(n); } } @@ -1286,7 +1304,7 @@ static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup) int ret; entry = rb_entry(n, struct root_info, rb_node); ret = lookup_ino_path(fd, entry); - if(ret < 0) + if (ret && ret != -ENOENT) return ret; n = rb_next(n); } @@ -1735,7 +1753,11 @@ char *btrfs_list_path_for_root(int fd, u64 root) struct root_info *entry; entry = rb_entry(n, struct root_info, rb_node); - resolve_root(&root_lookup, entry, top_id); + ret = resolve_root(&root_lookup, entry, top_id); + if (ret == -ENOENT && entry->root_id == root) { + ret_path = NULL; + break; + } if (entry->root_id == root) { ret_path = entry->full_path; entry->full_path = NULL; -- cgit v1.2.3