From 294c1bafd2a32b17f8c29a98d3daaf2397e332ce Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 12 Mar 2012 19:17:39 +0200 Subject: Btrfs-progs: nuke redundant zeroing in __list_subvol_search() There's no need to zero out things twice. Signed-off-by: Ilya Dryomov --- btrfs-list.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'btrfs-list.c') diff --git a/btrfs-list.c b/btrfs-list.c index 5f4a9bea..44a73de1 100644 --- a/btrfs-list.c +++ b/btrfs-list.c @@ -569,10 +569,6 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup) root_lookup_init(root_lookup); memset(&args, 0, sizeof(args)); - root_lookup_init(root_lookup); - - memset(&args, 0, sizeof(args)); - /* search in the tree of tree roots */ sk->tree_id = 1; -- cgit v1.2.3 From 55bf019ff439d0fd9fa1eb442418b9a627bc396a Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 12 Mar 2012 19:17:39 +0200 Subject: Btrfs-progs: refactor resolve_root() function a bit Don't pass a pointer to root_id to resolve_root(). It's always the same as ri->root_id, passing a pointer hints that root_id can somehow change which is not true. Signed-off-by: Ilya Dryomov --- btrfs-list.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) (limited to 'btrfs-list.c') diff --git a/btrfs-list.c b/btrfs-list.c index 44a73de1..cc1dc661 100644 --- a/btrfs-list.c +++ b/btrfs-list.c @@ -200,7 +200,7 @@ static int add_root(struct root_lookup *root_lookup, * in by lookup_ino_path */ static int resolve_root(struct root_lookup *rl, struct root_info *ri, - u64 *root_id, u64 *parent_id, u64 *top_id, char **path) + u64 *parent_id, u64 *top_id, char **path) { char *full_path = NULL; int len = 0; @@ -254,7 +254,6 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri, } } - *root_id = ri->root_id; *path = full_path; return 0; @@ -692,23 +691,23 @@ int list_subvols(int fd, int print_parent) n = rb_last(&root_lookup.root); while (n) { struct root_info *entry; - u64 root_id; u64 level; u64 parent_id; char *path; + entry = rb_entry(n, struct root_info, rb_node); - resolve_root(&root_lookup, entry, &root_id, &parent_id, - &level, &path); + resolve_root(&root_lookup, entry, &parent_id, &level, &path); if (print_parent) { printf("ID %llu parent %llu top level %llu path %s\n", - (unsigned long long)root_id, + (unsigned long long)entry->root_id, (unsigned long long)parent_id, (unsigned long long)level, path); } else { printf("ID %llu top level %llu path %s\n", - (unsigned long long)root_id, + (unsigned long long)entry->root_id, (unsigned long long)level, path); } + free(path); n = rb_prev(n); } @@ -914,17 +913,17 @@ char *path_for_root(int fd, u64 root) n = rb_last(&root_lookup.root); while (n) { struct root_info *entry; - u64 root_id; u64 parent_id; u64 level; char *path; + entry = rb_entry(n, struct root_info, rb_node); - resolve_root(&root_lookup, entry, &root_id, &parent_id, &level, - &path); - if (root_id == root) + resolve_root(&root_lookup, entry, &parent_id, &level, &path); + if (entry->root_id == root) ret_path = path; else free(path); + n = rb_prev(n); } -- cgit v1.2.3 From a0bdde58f840b47c6a4a7f2c8766706a44562cae Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Mon, 12 Mar 2012 19:17:39 +0200 Subject: Btrfs-progs: bring 'subvol get-default' back in Commit bab2c565 accidentally broke 'subvol get-default' command by removing almost all of the underlying code. Bring it back with some fixes and improvements. Signed-off-by: Ilya Dryomov --- btrfs-list.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 80 insertions(+), 1 deletion(-) (limited to 'btrfs-list.c') diff --git a/btrfs-list.c b/btrfs-list.c index cc1dc661..00c428b6 100644 --- a/btrfs-list.c +++ b/btrfs-list.c @@ -552,6 +552,60 @@ build: return full; } +static int get_default_subvolid(int fd, u64 *default_id) +{ + struct btrfs_ioctl_search_args args; + struct btrfs_ioctl_search_key *sk = &args.key; + struct btrfs_ioctl_search_header *sh; + u64 found = 0; + int ret; + + memset(&args, 0, sizeof(args)); + + /* + * search for a dir item with a name 'default' in the tree of + * tree roots, it should point us to a default root + */ + sk->tree_id = 1; + + /* don't worry about ancient format and request only one item */ + sk->nr_items = 1; + + sk->max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID; + sk->min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID; + sk->max_type = BTRFS_DIR_ITEM_KEY; + sk->min_type = BTRFS_DIR_ITEM_KEY; + sk->max_offset = (u64)-1; + sk->max_transid = (u64)-1; + + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args); + if (ret < 0) + return ret; + + /* the ioctl returns the number of items it found in nr_items */ + if (sk->nr_items == 0) + goto out; + + sh = (struct btrfs_ioctl_search_header *)args.buf; + + if (sh->type == BTRFS_DIR_ITEM_KEY) { + struct btrfs_dir_item *di; + int name_len; + char *name; + + di = (struct btrfs_dir_item *)(sh + 1); + name_len = btrfs_stack_dir_name_len(di); + name = (char *)(di + 1); + + if (!strncmp("default", name, name_len)) + found = btrfs_disk_key_objectid(&di->location); + } + +out: + *default_id = found; + return 0; +} + static int __list_subvol_search(int fd, struct root_lookup *root_lookup) { int ret; @@ -663,12 +717,32 @@ static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup) return 0; } -int list_subvols(int fd, int print_parent) +int list_subvols(int fd, int print_parent, int get_default) { struct root_lookup root_lookup; struct rb_node *n; + u64 default_id; int ret; + if (get_default) { + ret = get_default_subvolid(fd, &default_id); + if (ret) { + fprintf(stderr, "ERROR: can't perform the search - %s\n", + strerror(errno)); + return ret; + } + if (default_id == 0) { + fprintf(stderr, "ERROR: 'default' dir item not found\n"); + return ret; + } + + /* no need to resolve roots if FS_TREE is default */ + if (default_id == BTRFS_FS_TREE_OBJECTID) { + printf("ID 5 (FS_TREE)\n"); + return ret; + } + } + ret = __list_subvol_search(fd, &root_lookup); if (ret) { fprintf(stderr, "ERROR: can't perform the search - %s\n", @@ -696,6 +770,11 @@ int list_subvols(int fd, int print_parent) char *path; entry = rb_entry(n, struct root_info, rb_node); + if (get_default && entry->root_id != default_id) { + n = rb_prev(n); + continue; + } + resolve_root(&root_lookup, entry, &parent_id, &level, &path); if (print_parent) { printf("ID %llu parent %llu top level %llu path %s\n", -- cgit v1.2.3