diff options
| -rw-r--r-- | libbtrfsutil/btrfsutil.h | 15 | ||||
| -rw-r--r-- | libbtrfsutil/errors.c | 6 | ||||
| -rw-r--r-- | libbtrfsutil/python/tests/test_subvolume.py | 180 | ||||
| -rw-r--r-- | libbtrfsutil/subvolume.c | 354 |
4 files changed, 450 insertions, 105 deletions
diff --git a/libbtrfsutil/btrfsutil.h b/libbtrfsutil/btrfsutil.h index c1925007..d88c39e5 100644 --- a/libbtrfsutil/btrfsutil.h +++ b/libbtrfsutil/btrfsutil.h @@ -64,6 +64,9 @@ enum btrfs_util_error { BTRFS_UTIL_ERROR_START_SYNC_FAILED, BTRFS_UTIL_ERROR_WAIT_SYNC_FAILED, BTRFS_UTIL_ERROR_GET_SUBVOL_INFO_FAILED, + BTRFS_UTIL_ERROR_GET_SUBVOL_ROOTREF_FAILED, + BTRFS_UTIL_ERROR_INO_LOOKUP_USER_FAILED, + BTRFS_UTIL_ERROR_FS_INFO_FAILED, }; /** @@ -507,6 +510,12 @@ struct btrfs_util_subvolume_iterator; * @flags: Bitmask of BTRFS_UTIL_SUBVOLUME_ITERATOR_* flags. * @ret: Returned iterator. * + * Subvolume iterators require appropriate privilege (CAP_SYS_ADMIN) unless @top + * is zero and the kernel supports BTRFS_IOC_GET_SUBVOL_ROOTREF and + * BTRFS_IOC_INO_LOOKUP_USER (kernel >= 4.18). In this case, subvolumes which + * cannot be accessed (e.g., due to permissions or other mounts) will be + * skipped. + * * The returned iterator must be freed with * btrfs_util_destroy_subvolume_iterator(). * @@ -555,7 +564,8 @@ int btrfs_util_subvolume_iterator_fd(const struct btrfs_util_subvolume_iterator * Must be freed with free(). * @id_ret: Returned subvolume ID. May be %NULL. * - * This requires appropriate privilege (CAP_SYS_ADMIN). + * This requires appropriate privilege (CAP_SYS_ADMIN) for kernels < 4.18. See + * btrfs_util_create_subvolume_iterator(). * * Return: %BTRFS_UTIL_OK on success, %BTRFS_UTIL_ERROR_STOP_ITERATION if there * are no more subvolumes, non-zero error code on failure. @@ -574,7 +584,8 @@ enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvo * This convenience function basically combines * btrfs_util_subvolume_iterator_next() and btrfs_util_subvolume_info(). * - * This requires appropriate privilege (CAP_SYS_ADMIN). + * This requires appropriate privilege (CAP_SYS_ADMIN) for kernels < 4.18. See + * btrfs_util_create_subvolume_iterator(). * * Return: See btrfs_util_subvolume_iterator_next(). */ diff --git a/libbtrfsutil/errors.c b/libbtrfsutil/errors.c index cf968b03..d39b38d0 100644 --- a/libbtrfsutil/errors.c +++ b/libbtrfsutil/errors.c @@ -47,6 +47,12 @@ static const char * const error_messages[] = { [BTRFS_UTIL_ERROR_WAIT_SYNC_FAILED] = "Could not wait for filesystem sync", [BTRFS_UTIL_ERROR_GET_SUBVOL_INFO_FAILED] = "Could not get subvolume information with BTRFS_IOC_GET_SUBVOL_INFO", + [BTRFS_UTIL_ERROR_GET_SUBVOL_ROOTREF_FAILED] = + "Could not get rootref information with BTRFS_IOC_GET_SUBVOL_ROOTREF", + [BTRFS_UTIL_ERROR_INO_LOOKUP_USER_FAILED] = + "Could not resolve subvolume path with BTRFS_IOC_INO_LOOKUP_USER", + [BTRFS_UTIL_ERROR_FS_INFO_FAILED] = + "Could not get filesystem information", }; PUBLIC const char *btrfs_util_strerror(enum btrfs_util_error err) diff --git a/libbtrfsutil/python/tests/test_subvolume.py b/libbtrfsutil/python/tests/test_subvolume.py index 55ebf34d..99ec97bc 100644 --- a/libbtrfsutil/python/tests/test_subvolume.py +++ b/libbtrfsutil/python/tests/test_subvolume.py @@ -20,6 +20,7 @@ import errno import os import os.path from pathlib import PurePath +import subprocess import traceback import btrfsutil @@ -27,6 +28,8 @@ from tests import ( BtrfsTestCase, drop_privs, HAVE_PATH_LIKE, + NOBODY_UID, + regain_privs, skipUnlessHaveNobody, ) @@ -354,69 +357,136 @@ class TestSubvolume(BtrfsTestCase): with self.subTest(type=type(arg)): self.assertEqual(btrfsutil.deleted_subvolumes(arg), [256]) - def test_subvolume_iterator(self): - pwd = os.getcwd() - try: - os.chdir(self.mountpoint) - btrfsutil.create_subvolume('foo') - - with btrfsutil.SubvolumeIterator('.', info=True) as it: - path, subvol = next(it) - self.assertEqual(path, 'foo') - self.assertIsInstance(subvol, btrfsutil.SubvolumeInfo) - self.assertEqual(subvol.id, 256) - self.assertEqual(subvol.parent_id, 5) - self.assertRaises(StopIteration, next, it) - - btrfsutil.create_subvolume('foo/bar') - btrfsutil.create_subvolume('foo/bar/baz') - - subvols = [ - ('foo', 256), - ('foo/bar', 257), - ('foo/bar/baz', 258), - ] - - for arg in self.path_or_fd('.'): - with self.subTest(type=type(arg)), btrfsutil.SubvolumeIterator(arg) as it: - self.assertEqual(list(it), subvols) - with btrfsutil.SubvolumeIterator('.', top=0) as it: + def _test_subvolume_iterator(self): + btrfsutil.create_subvolume('foo') + + with btrfsutil.SubvolumeIterator('.', info=True) as it: + path, subvol = next(it) + self.assertEqual(path, 'foo') + self.assertIsInstance(subvol, btrfsutil.SubvolumeInfo) + self.assertEqual(subvol.id, 256) + self.assertEqual(subvol.parent_id, 5) + self.assertRaises(StopIteration, next, it) + + btrfsutil.create_subvolume('foo/bar') + btrfsutil.create_subvolume('foo/bar/baz') + + subvols = [ + ('foo', 256), + ('foo/bar', 257), + ('foo/bar/baz', 258), + ] + + for arg in self.path_or_fd('.'): + with self.subTest(type=type(arg)), btrfsutil.SubvolumeIterator(arg) as it: self.assertEqual(list(it), subvols) + with btrfsutil.SubvolumeIterator('.', top=0) as it: + self.assertEqual(list(it), subvols) + if os.geteuid() == 0: with btrfsutil.SubvolumeIterator('foo', top=5) as it: self.assertEqual(list(it), subvols) - with btrfsutil.SubvolumeIterator('.', post_order=True) as it: - self.assertEqual(list(it), - [('foo/bar/baz', 258), - ('foo/bar', 257), - ('foo', 256)]) + with btrfsutil.SubvolumeIterator('.', post_order=True) as it: + self.assertEqual(list(it), + [('foo/bar/baz', 258), + ('foo/bar', 257), + ('foo', 256)]) - subvols = [ - ('bar', 257), - ('bar/baz', 258), - ] + subvols = [ + ('bar', 257), + ('bar/baz', 258), + ] + if os.geteuid() == 0: with btrfsutil.SubvolumeIterator('.', top=256) as it: self.assertEqual(list(it), subvols) - with btrfsutil.SubvolumeIterator('foo') as it: - self.assertEqual(list(it), subvols) - with btrfsutil.SubvolumeIterator('foo', top=0) as it: - self.assertEqual(list(it), subvols) + with btrfsutil.SubvolumeIterator('foo') as it: + self.assertEqual(list(it), subvols) + with btrfsutil.SubvolumeIterator('foo', top=0) as it: + self.assertEqual(list(it), subvols) + + os.rename('foo/bar/baz', 'baz') + os.mkdir('dir') + btrfsutil.create_subvolume('dir/qux') + os.mkdir('dir/qux/dir2') + btrfsutil.create_subvolume('dir/qux/dir2/quux') + + subvols = [ + ('baz', 258), + ('dir/qux', 259), + ('dir/qux/dir2/quux', 260), + ('foo', 256), + ('foo/bar', 257), + ] + + # Test various corner cases of the unprivileged implementation + # where we can't access the subvolume. + if os.geteuid() != 0: + with regain_privs(): + # We don't have permission to traverse the path. + os.mkdir('directory_perms', 0o700) + btrfsutil.create_subvolume('directory_perms/subvol') + + # We don't have permission to resolve the subvolume path. + os.mkdir('subvol_perms', 0o755) + btrfsutil.create_subvolume('subvol_perms/subvol') + os.chmod('subvol_perms/subvol', 0o700) + + # The path doesn't exist. + os.mkdir('enoent', 0o755) + btrfsutil.create_subvolume('enoent/subvol') + subprocess.check_call(['mount', '-t', 'tmpfs', 'tmpfs', 'enoent']) + + # The path exists but it's not a subvolume. + os.mkdir('notsubvol', 0o755) + btrfsutil.create_subvolume('notsubvol/subvol') + subprocess.check_call(['mount', '-t', 'tmpfs', 'tmpfs', 'notsubvol']) + os.mkdir('notsubvol/subvol') + + # The path exists and is a subvolume, but on a different + # filesystem. + os.mkdir('wrongfs', 0o755) + btrfsutil.create_subvolume('wrongfs/subvol') + other_mountpoint, _ = self.mount_btrfs() + subprocess.check_call(['mount', '--bind', '--', + other_mountpoint, 'wrongfs/subvol']) + + # The path exists and is a subvolume on the same + # filesystem, but not the right one. + os.mkdir('wrongsubvol', 0o755) + btrfsutil.create_subvolume('wrongsubvol/subvol') + subprocess.check_call(['mount', '--bind', 'baz', 'wrongsubvol/subvol']) + + + with btrfsutil.SubvolumeIterator('.') as it: + self.assertEqual(sorted(it), subvols) + with btrfsutil.SubvolumeIterator('.', post_order=True) as it: + self.assertEqual(sorted(it), subvols) + + with btrfsutil.SubvolumeIterator('.') as it: + self.assertGreaterEqual(it.fileno(), 0) + it.close() + with self.assertRaises(ValueError): + next(iter(it)) + with self.assertRaises(ValueError): + it.fileno() + it.close() - os.rename('foo/bar/baz', 'baz') - with btrfsutil.SubvolumeIterator('.') as it: - self.assertEqual(sorted(it), - [('baz', 258), - ('foo', 256), - ('foo/bar', 257)]) - - with btrfsutil.SubvolumeIterator('.') as it: - self.assertGreaterEqual(it.fileno(), 0) - it.close() - with self.assertRaises(ValueError): - next(iter(it)) - with self.assertRaises(ValueError): - it.fileno() - it.close() + def test_subvolume_iterator(self): + pwd = os.getcwd() + try: + os.chdir(self.mountpoint) + self._test_subvolume_iterator() + finally: + os.chdir(pwd) + + @skipUnlessHaveNobody + def test_subvolume_iterator_unprivileged(self): + os.chown(self.mountpoint, NOBODY_UID, -1) + pwd = os.getcwd() + try: + os.chdir(self.mountpoint) + with drop_privs(): + self._test_subvolume_iterator() finally: os.chdir(pwd) diff --git a/libbtrfsutil/subvolume.c b/libbtrfsutil/subvolume.c index 69654db4..60ab9f9d 100644 --- a/libbtrfsutil/subvolume.c +++ b/libbtrfsutil/subvolume.c @@ -749,13 +749,28 @@ PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_fd(int parent_fd, #define BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD (1 << 30) struct search_stack_entry { - struct btrfs_ioctl_search_args search; - size_t items_pos, buf_off; + union { + /* Used for subvolume_iterator_next_tree_search(). */ + struct { + struct btrfs_ioctl_search_args search; + size_t buf_off; + }; + /* Used for subvolume_iterator_next_unprivileged(). */ + struct { + uint64_t id; + struct btrfs_ioctl_get_subvol_rootref_args rootref_args; + }; + }; + /* Used for both. */ + size_t items_pos; size_t path_len; }; struct btrfs_util_subvolume_iterator { + bool use_tree_search; int fd; + /* cur_fd is only used for subvolume_iterator_next_unprivileged(). */ + int cur_fd; int flags; struct search_stack_entry *search_stack; @@ -766,6 +781,58 @@ struct btrfs_util_subvolume_iterator { size_t cur_path_capacity; }; +static struct search_stack_entry *top_search_stack_entry(struct btrfs_util_subvolume_iterator *iter) +{ + return &iter->search_stack[iter->search_stack_len - 1]; +} + +/* + * Check that a path that we opened is the subvolume which we expect. It may not + * be if there is another filesystem mounted over a parent directory or the + * subvolume itself. + */ +static enum btrfs_util_error check_expected_subvolume(int fd, int parent_fd, + uint64_t tree_id) +{ + struct btrfs_ioctl_fs_info_args parent_fs_info, fs_info; + enum btrfs_util_error err; + uint64_t id; + int ret; + + /* Make sure it's a subvolume. */ + err = btrfs_util_is_subvolume_fd(fd); + if (err == BTRFS_UTIL_ERROR_NOT_BTRFS || + err == BTRFS_UTIL_ERROR_NOT_SUBVOLUME) { + errno = ENOENT; + return BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND; + } else if (err) { + return err; + } + + /* Make sure it's on the same filesystem. */ + ret = ioctl(parent_fd, BTRFS_IOC_FS_INFO, &parent_fs_info); + if (ret == -1) + return BTRFS_UTIL_ERROR_FS_INFO_FAILED; + ret = ioctl(fd, BTRFS_IOC_FS_INFO, &fs_info); + if (ret == -1) + return BTRFS_UTIL_ERROR_FS_INFO_FAILED; + if (memcmp(parent_fs_info.fsid, fs_info.fsid, sizeof(fs_info.fsid)) != 0) { + errno = ENOENT; + return BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND; + } + + /* Make sure it's the subvolume that we expected. */ + err = btrfs_util_subvolume_id_fd(fd, &id); + if (err) + return err; + if (id != tree_id) { + errno = ENOENT; + return BTRFS_UTIL_ERROR_SUBVOLUME_NOT_FOUND; + } + + return BTRFS_UTIL_OK; +} + static enum btrfs_util_error append_to_search_stack(struct btrfs_util_subvolume_iterator *iter, uint64_t tree_id, size_t path_len) @@ -786,24 +853,84 @@ static enum btrfs_util_error append_to_search_stack(struct btrfs_util_subvolume_ iter->search_stack = new_search_stack; } - entry = &iter->search_stack[iter->search_stack_len++]; + entry = &iter->search_stack[iter->search_stack_len]; - memset(&entry->search, 0, sizeof(entry->search)); - entry->search.key.tree_id = BTRFS_ROOT_TREE_OBJECTID; - entry->search.key.min_objectid = tree_id; - entry->search.key.max_objectid = tree_id; - entry->search.key.min_type = BTRFS_ROOT_REF_KEY; - entry->search.key.max_type = BTRFS_ROOT_REF_KEY; - entry->search.key.min_offset = 0; - entry->search.key.max_offset = UINT64_MAX; - entry->search.key.min_transid = 0; - entry->search.key.max_transid = UINT64_MAX; - entry->search.key.nr_items = 0; + memset(entry, 0, sizeof(*entry)); + entry->path_len = path_len; + if (iter->use_tree_search) { + entry->search.key.tree_id = BTRFS_ROOT_TREE_OBJECTID; + entry->search.key.min_objectid = tree_id; + entry->search.key.max_objectid = tree_id; + entry->search.key.min_type = BTRFS_ROOT_REF_KEY; + entry->search.key.max_type = BTRFS_ROOT_REF_KEY; + entry->search.key.min_offset = 0; + entry->search.key.max_offset = UINT64_MAX; + entry->search.key.min_transid = 0; + entry->search.key.max_transid = UINT64_MAX; + entry->search.key.nr_items = 0; + } else { + entry->id = tree_id; - entry->items_pos = 0; - entry->buf_off = 0; + if (iter->search_stack_len) { + struct search_stack_entry *top; + enum btrfs_util_error err; + char *path; + int fd; - entry->path_len = path_len; + top = top_search_stack_entry(iter); + path = &iter->cur_path[top->path_len]; + if (*path == '/') + path++; + fd = openat(iter->cur_fd, path, O_RDONLY); + if (fd == -1) + return BTRFS_UTIL_ERROR_OPEN_FAILED; + + err = check_expected_subvolume(fd, iter->cur_fd, + tree_id); + if (err) { + close(fd); + return err; + } + + close(iter->cur_fd); + iter->cur_fd = fd; + } + } + + iter->search_stack_len++; + + return BTRFS_UTIL_OK; +} + +static enum btrfs_util_error pop_search_stack(struct btrfs_util_subvolume_iterator *iter) +{ + struct search_stack_entry *top, *parent; + int fd, parent_fd; + size_t i; + + if (iter->use_tree_search || iter->search_stack_len == 1) { + iter->search_stack_len--; + return BTRFS_UTIL_OK; + } + + top = top_search_stack_entry(iter); + iter->search_stack_len--; + parent = top_search_stack_entry(iter); + + fd = iter->cur_fd; + for (i = parent->path_len; i < top->path_len; i++) { + if (i == 0 || iter->cur_path[i] == '/') { + parent_fd = openat(fd, "..", O_RDONLY); + if (fd != iter->cur_fd) + SAVE_ERRNO_AND_CLOSE(fd); + if (parent_fd == -1) + return BTRFS_UTIL_ERROR_OPEN_FAILED; + fd = parent_fd; + } + } + if (iter->cur_fd != iter->fd) + close(iter->cur_fd); + iter->cur_fd = fd; return BTRFS_UTIL_OK; } @@ -836,12 +963,14 @@ PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd, { struct btrfs_util_subvolume_iterator *iter; enum btrfs_util_error err; + bool use_tree_search; if (flags & ~BTRFS_UTIL_SUBVOLUME_ITERATOR_MASK) { errno = EINVAL; return BTRFS_UTIL_ERROR_INVALID_ARGUMENT; } + use_tree_search = top != 0 || is_root(); if (top == 0) { err = btrfs_util_is_subvolume_fd(fd); if (err) @@ -857,7 +986,9 @@ PUBLIC enum btrfs_util_error btrfs_util_create_subvolume_iterator_fd(int fd, return BTRFS_UTIL_ERROR_NO_MEMORY; iter->fd = fd; + iter->cur_fd = fd; iter->flags = flags; + iter->use_tree_search = use_tree_search; iter->search_stack_len = 0; iter->search_stack_capacity = 4; @@ -1166,6 +1297,8 @@ PUBLIC void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_it if (iter) { free(iter->cur_path); free(iter->search_stack); + if (iter->cur_fd != iter->fd) + SAVE_ERRNO_AND_CLOSE(iter->cur_fd); if (iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_CLOSE_FD) SAVE_ERRNO_AND_CLOSE(iter->fd); free(iter); @@ -1177,32 +1310,14 @@ PUBLIC int btrfs_util_subvolume_iterator_fd(const struct btrfs_util_subvolume_it return iter->fd; } -static struct search_stack_entry *top_search_stack_entry(struct btrfs_util_subvolume_iterator *iter) -{ - return &iter->search_stack[iter->search_stack_len - 1]; -} - static enum btrfs_util_error build_subvol_path(struct btrfs_util_subvolume_iterator *iter, - const struct btrfs_ioctl_search_header *header, - const struct btrfs_root_ref *ref, - const char *name, + const char *name, size_t name_len, + const char *dir, size_t dir_len, size_t *path_len_ret) { - struct btrfs_ioctl_ino_lookup_args lookup = { - .treeid = header->objectid, - .objectid = le64_to_cpu(ref->dirid), - }; struct search_stack_entry *top = top_search_stack_entry(iter); - size_t dir_len, name_len, path_len; + size_t path_len; char *p; - int ret; - - ret = ioctl(iter->fd, BTRFS_IOC_INO_LOOKUP, &lookup); - if (ret == -1) - return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED; - - dir_len = strlen(lookup.name); - name_len = le16_to_cpu(ref->name_len); path_len = top->path_len; /* @@ -1220,33 +1335,75 @@ static enum btrfs_util_error build_subvol_path(struct btrfs_util_subvolume_itera path_len++; path_len += name_len; - if (path_len > iter->cur_path_capacity) { - char *tmp = realloc(iter->cur_path, path_len); + /* We need one extra character for the NUL terminator. */ + if (path_len + 1 > iter->cur_path_capacity) { + char *tmp = realloc(iter->cur_path, path_len + 1); if (!tmp) return BTRFS_UTIL_ERROR_NO_MEMORY; iter->cur_path = tmp; - iter->cur_path_capacity = path_len; + iter->cur_path_capacity = path_len + 1; } p = iter->cur_path + top->path_len; if (top->path_len && dir_len) *p++ = '/'; - memcpy(p, lookup.name, dir_len); + memcpy(p, dir, dir_len); p += dir_len; if (top->path_len && !dir_len && name_len) *p++ = '/'; memcpy(p, name, name_len); p += name_len; + *p = '\0'; *path_len_ret = path_len; return BTRFS_UTIL_OK; } -PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter, - char **path_ret, - uint64_t *id_ret) +static enum btrfs_util_error build_subvol_path_privileged(struct btrfs_util_subvolume_iterator *iter, + const struct btrfs_ioctl_search_header *header, + const struct btrfs_root_ref *ref, + const char *name, + size_t *path_len_ret) +{ + struct btrfs_ioctl_ino_lookup_args lookup = { + .treeid = header->objectid, + .objectid = le64_to_cpu(ref->dirid), + }; + int ret; + + ret = ioctl(iter->fd, BTRFS_IOC_INO_LOOKUP, &lookup); + if (ret == -1) + return BTRFS_UTIL_ERROR_INO_LOOKUP_FAILED; + + return build_subvol_path(iter, name, le16_to_cpu(ref->name_len), + lookup.name, strlen(lookup.name), + path_len_ret); +} + +static enum btrfs_util_error build_subvol_path_unprivileged(struct btrfs_util_subvolume_iterator *iter, + uint64_t treeid, + uint64_t dirid, + size_t *path_len_ret) +{ + struct btrfs_ioctl_ino_lookup_user_args args = { + .treeid = treeid, + .dirid = dirid, + }; + int ret; + + ret = ioctl(iter->cur_fd, BTRFS_IOC_INO_LOOKUP_USER, &args); + if (ret == -1) + return BTRFS_UTIL_ERROR_INO_LOOKUP_USER_FAILED; + + return build_subvol_path(iter, args.name, strlen(args.name), + args.path, strlen(args.path), path_len_ret); +} + +static enum btrfs_util_error subvolume_iterator_next_tree_search(struct btrfs_util_subvolume_iterator *iter, + char **path_ret, + uint64_t *id_ret) { struct search_stack_entry *top; const struct btrfs_ioctl_search_header *header; @@ -1273,7 +1430,10 @@ PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_uti top->buf_off = 0; if (top->search.key.nr_items == 0) { - iter->search_stack_len--; + /* + * This never fails for use_tree_search. + */ + pop_search_stack(iter); if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) && iter->search_stack_len) goto out; @@ -1293,7 +1453,8 @@ PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_uti ref = (struct btrfs_root_ref *)(header + 1); name = (const char *)(ref + 1); - err = build_subvol_path(iter, header, ref, name, &path_len); + err = build_subvol_path_privileged(iter, header, ref, name, + &path_len); if (err) return err; @@ -1320,6 +1481,100 @@ out: return BTRFS_UTIL_OK; } +static enum btrfs_util_error subvolume_iterator_next_unprivileged(struct btrfs_util_subvolume_iterator *iter, + char **path_ret, + uint64_t *id_ret) +{ + struct search_stack_entry *top; + uint64_t treeid, dirid; + enum btrfs_util_error err; + size_t path_len; + int ret; + + for (;;) { + for (;;) { + if (iter->search_stack_len == 0) + return BTRFS_UTIL_ERROR_STOP_ITERATION; + + top = top_search_stack_entry(iter); + if (top->items_pos < top->rootref_args.num_items) { + break; + } else { + ret = ioctl(iter->cur_fd, + BTRFS_IOC_GET_SUBVOL_ROOTREF, + &top->rootref_args); + if (ret == -1 && errno != EOVERFLOW) + return BTRFS_UTIL_ERROR_GET_SUBVOL_ROOTREF_FAILED; + top->items_pos = 0; + + if (top->rootref_args.num_items == 0) { + err = pop_search_stack(iter); + if (err) + return err; + if ((iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER) && + iter->search_stack_len) + goto out; + } + } + } + + treeid = top->rootref_args.rootref[top->items_pos].treeid; + dirid = top->rootref_args.rootref[top->items_pos].dirid; + top->items_pos++; + err = build_subvol_path_unprivileged(iter, treeid, dirid, + &path_len); + if (err) { + /* Skip the subvolume if we can't access it. */ + if (errno == EACCES) + continue; + return err; + } + + err = append_to_search_stack(iter, treeid, path_len); + if (err) { + /* + * Skip the subvolume if it does not exist (which can + * happen if there is another filesystem mounted over a + * parent directory) or we don't have permission to + * access it. + */ + if (errno == ENOENT || errno == EACCES) + continue; + return err; + } + + if (!(iter->flags & BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER)) { + top = top_search_stack_entry(iter); + goto out; + } + } + +out: + if (path_ret) { + *path_ret = malloc(top->path_len + 1); + if (!*path_ret) + return BTRFS_UTIL_ERROR_NO_MEMORY; + memcpy(*path_ret, iter->cur_path, top->path_len); + (*path_ret)[top->path_len] = '\0'; + } + if (id_ret) + *id_ret = top->id; + return BTRFS_UTIL_OK; +} + +PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next(struct btrfs_util_subvolume_iterator *iter, + char **path_ret, + uint64_t *id_ret) +{ + if (iter->use_tree_search) { + return subvolume_iterator_next_tree_search(iter, path_ret, + id_ret); + } else { + return subvolume_iterator_next_unprivileged(iter, path_ret, + id_ret); + } +} + PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrfs_util_subvolume_iterator *iter, char **path_ret, struct btrfs_util_subvolume_info *subvol) @@ -1331,7 +1586,10 @@ PUBLIC enum btrfs_util_error btrfs_util_subvolume_iterator_next_info(struct btrf if (err) return err; - return btrfs_util_subvolume_info_fd(iter->fd, id, subvol); + if (iter->use_tree_search) + return btrfs_util_subvolume_info_fd(iter->fd, id, subvol); + else + return btrfs_util_subvolume_info_fd(iter->cur_fd, 0, subvol); } PUBLIC enum btrfs_util_error btrfs_util_deleted_subvolumes(const char *path, |