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authorOmar Sandoval <osandov@fb.com>2018-01-18 14:26:35 -0800
committerDavid Sterba <dsterba@suse.com>2018-03-06 11:28:37 +0100
commit678da5a7f71ed7fbc887e40cc8ef91008c6fe843 (patch)
tree1a2f01608affa5b7b4a9cd91976996c82450044a /libbtrfsutil
parentcfa89b30821fedb48ca163a9c1128c4db596c911 (diff)
libbtrfsutil: add btrfs_util_delete_subvolume()
We also support recursive deletion using a subvolume iterator. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'libbtrfsutil')
-rw-r--r--libbtrfsutil/btrfsutil.h33
-rw-r--r--libbtrfsutil/python/btrfsutilpy.h1
-rw-r--r--libbtrfsutil/python/module.c8
-rw-r--r--libbtrfsutil/python/subvolume.c27
-rw-r--r--libbtrfsutil/python/tests/test_subvolume.py48
-rw-r--r--libbtrfsutil/subvolume.c102
6 files changed, 219 insertions, 0 deletions
diff --git a/libbtrfsutil/btrfsutil.h b/libbtrfsutil/btrfsutil.h
index ccb2c17..6717b65 100644
--- a/libbtrfsutil/btrfsutil.h
+++ b/libbtrfsutil/btrfsutil.h
@@ -450,6 +450,39 @@ enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd, int parent_fd,
uint64_t *async_transid,
struct btrfs_util_qgroup_inherit *qgroup_inherit);
+/**
+ * BTRFS_UTIL_DELETE_SUBVOLUME_RECURSIVE - Delete subvolumes beneath the given
+ * subvolume before attempting to delete the given subvolume.
+ *
+ * If this flag is not used, deleting a subvolume with child subvolumes is an
+ * error. Note that this is currently implemented in userspace non-atomically.
+ * It requires appropriate privilege (CAP_SYS_ADMIN).
+ */
+#define BTRFS_UTIL_DELETE_SUBVOLUME_RECURSIVE (1 << 0)
+#define BTRFS_UTIL_DELETE_SUBVOLUME_MASK ((1 << 1) - 1)
+
+/**
+ * btrfs_util_delete_subvolume() - Delete a subvolume or snapshot.
+ * @path: Path of the subvolume to delete.
+ * @flags: Bitmask of BTRFS_UTIL_DELETE_SUBVOLUME_* flags.
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_delete_subvolume(const char *path, int flags);
+
+/**
+ * btrfs_util_delete_subvolume_fd() - Delete a subvolume or snapshot given its
+ * parent and name.
+ * @parent_fd: File descriptor of the subvolume's parent directory.
+ * @name: Name of the subvolume.
+ * @flags: See btrfs_util_delete_subvolume().
+ *
+ * Return: %BTRFS_UTIL_OK on success, non-zero error code on failure.
+ */
+enum btrfs_util_error btrfs_util_delete_subvolume_fd(int parent_fd,
+ const char *name,
+ int flags);
+
struct btrfs_util_subvolume_iterator;
/**
diff --git a/libbtrfsutil/python/btrfsutilpy.h b/libbtrfsutil/python/btrfsutilpy.h
index 59c7e99..0ee6afa 100644
--- a/libbtrfsutil/python/btrfsutilpy.h
+++ b/libbtrfsutil/python/btrfsutilpy.h
@@ -74,6 +74,7 @@ PyObject *get_default_subvolume(PyObject *self, PyObject *args, PyObject *kwds);
PyObject *set_default_subvolume(PyObject *self, PyObject *args, PyObject *kwds);
PyObject *create_subvolume(PyObject *self, PyObject *args, PyObject *kwds);
PyObject *create_snapshot(PyObject *self, PyObject *args, PyObject *kwds);
+PyObject *delete_subvolume(PyObject *self, PyObject *args, PyObject *kwds);
void add_module_constants(PyObject *m);
diff --git a/libbtrfsutil/python/module.c b/libbtrfsutil/python/module.c
index 3f0f617..fe25f4b 100644
--- a/libbtrfsutil/python/module.c
+++ b/libbtrfsutil/python/module.c
@@ -227,6 +227,14 @@ static PyMethodDef btrfsutil_methods[] = {
"read_only -- create a read-only snapshot\n"
"async -- create the subvolume without waiting for it to commit to\n"
"disk and return the transaction ID"},
+ {"delete_subvolume", (PyCFunction)delete_subvolume,
+ METH_VARARGS | METH_KEYWORDS,
+ "delete_subvolume(path, recursive=False)\n\n"
+ "Delete a subvolume or snapshot.\n\n"
+ "Arguments:\n"
+ "path -- string, bytes, or path-like object\n"
+ "recursive -- if the given subvolume has child subvolumes, delete\n"
+ "them instead of failing"},
{},
};
diff --git a/libbtrfsutil/python/subvolume.c b/libbtrfsutil/python/subvolume.c
index a158ade..eb3f6e2 100644
--- a/libbtrfsutil/python/subvolume.c
+++ b/libbtrfsutil/python/subvolume.c
@@ -398,6 +398,33 @@ PyObject *create_snapshot(PyObject *self, PyObject *args, PyObject *kwds)
Py_RETURN_NONE;
}
+PyObject *delete_subvolume(PyObject *self, PyObject *args, PyObject *kwds)
+{
+ static char *keywords[] = {"path", "recursive", NULL};
+ struct path_arg path = {.allow_fd = false};
+ enum btrfs_util_error err;
+ int recursive = 0;
+ int flags = 0;
+
+ if (!PyArg_ParseTupleAndKeywords(args, kwds, "O&|p:delete_subvolume",
+ keywords, &path_converter, &path,
+ &recursive))
+ return NULL;
+
+ if (recursive)
+ flags |= BTRFS_UTIL_DELETE_SUBVOLUME_RECURSIVE;
+
+ err = btrfs_util_delete_subvolume(path.path, flags);
+ if (err) {
+ SetFromBtrfsUtilErrorWithPath(err, &path);
+ path_cleanup(&path);
+ return NULL;
+ }
+
+ path_cleanup(&path);
+ Py_RETURN_NONE;
+}
+
typedef struct {
PyObject_HEAD
struct btrfs_util_subvolume_iterator *iter;
diff --git a/libbtrfsutil/python/tests/test_subvolume.py b/libbtrfsutil/python/tests/test_subvolume.py
index 2951154..08083ab 100644
--- a/libbtrfsutil/python/tests/test_subvolume.py
+++ b/libbtrfsutil/python/tests/test_subvolume.py
@@ -270,6 +270,54 @@ class TestSubvolume(BtrfsTestCase):
btrfsutil.create_snapshot(subvol, snapshot + '4', read_only=True)
self.assertTrue(btrfsutil.get_subvolume_read_only(snapshot + '4'))
+ def test_delete_subvolume(self):
+ subvol = os.path.join(self.mountpoint, 'subvol')
+ btrfsutil.create_subvolume(subvol + '1')
+ self.assertTrue(os.path.exists(subvol + '1'))
+ btrfsutil.create_subvolume(subvol + '2')
+ self.assertTrue(os.path.exists(subvol + '2'))
+ btrfsutil.create_subvolume(subvol + '3')
+ self.assertTrue(os.path.exists(subvol + '3'))
+
+ btrfsutil.delete_subvolume(subvol + '1')
+ self.assertFalse(os.path.exists(subvol + '1'))
+ btrfsutil.delete_subvolume((subvol + '2').encode())
+ self.assertFalse(os.path.exists(subvol + '2'))
+ if HAVE_PATH_LIKE:
+ btrfsutil.delete_subvolume(PurePath(subvol + '3'))
+ self.assertFalse(os.path.exists(subvol + '3'))
+
+ # Test deleting subvolumes under '/' in a chroot.
+ pid = os.fork()
+ if pid == 0:
+ try:
+ os.chroot(self.mountpoint)
+ os.chdir('/')
+ btrfsutil.create_subvolume('/subvol4')
+ self.assertTrue(os.path.exists('/subvol4'))
+ btrfsutil.delete_subvolume('/subvol4')
+ self.assertFalse(os.path.exists('/subvol4'))
+ with self.assertRaises(btrfsutil.BtrfsUtilError):
+ btrfsutil.delete_subvolume('/')
+ os._exit(0)
+ except Exception:
+ traceback.print_exc()
+ os._exit(1)
+ wstatus = os.waitpid(pid, 0)[1]
+ self.assertTrue(os.WIFEXITED(wstatus))
+ self.assertEqual(os.WEXITSTATUS(wstatus), 0)
+
+ btrfsutil.create_subvolume(subvol + '5')
+ btrfsutil.create_subvolume(subvol + '5/foo')
+ btrfsutil.create_subvolume(subvol + '5/bar')
+ btrfsutil.create_subvolume(subvol + '5/bar/baz')
+ btrfsutil.create_subvolume(subvol + '5/bar/qux')
+ btrfsutil.create_subvolume(subvol + '5/quux')
+ with self.assertRaises(btrfsutil.BtrfsUtilError):
+ btrfsutil.delete_subvolume(subvol + '5')
+ btrfsutil.delete_subvolume(subvol + '5', recursive=True)
+ self.assertFalse(os.path.exists(subvol + '5'))
+
def test_subvolume_iterator(self):
pwd = os.getcwd()
try:
diff --git a/libbtrfsutil/subvolume.c b/libbtrfsutil/subvolume.c
index 28b38e5..56cd2c6 100644
--- a/libbtrfsutil/subvolume.c
+++ b/libbtrfsutil/subvolume.c
@@ -1005,6 +1005,108 @@ PUBLIC enum btrfs_util_error btrfs_util_create_snapshot_fd2(int fd,
return BTRFS_UTIL_OK;
}
+static enum btrfs_util_error delete_subvolume_children(int parent_fd,
+ const char *name)
+{
+ struct btrfs_util_subvolume_iterator *iter;
+ enum btrfs_util_error err;
+ int fd;
+
+ fd = openat(parent_fd, name, O_RDONLY);
+ if (fd == -1)
+ return BTRFS_UTIL_ERROR_OPEN_FAILED;
+
+ err = btrfs_util_create_subvolume_iterator_fd(fd, 0,
+ BTRFS_UTIL_SUBVOLUME_ITERATOR_POST_ORDER,
+ &iter);
+ if (err)
+ goto out;
+
+ for (;;) {
+ char child_name[BTRFS_PATH_NAME_MAX + 1];
+ char *child_path;
+ int child_parent_fd;
+
+ err = btrfs_util_subvolume_iterator_next(iter, &child_path,
+ NULL);
+ if (err) {
+ if (err == BTRFS_UTIL_ERROR_STOP_ITERATION)
+ err = BTRFS_UTIL_OK;
+ break;
+ }
+
+ err = openat_parent_and_name(fd, child_path, child_name,
+ sizeof(child_name),
+ &child_parent_fd);
+ free(child_path);
+ if (err)
+ break;
+
+ err = btrfs_util_delete_subvolume_fd(child_parent_fd,
+ child_name, 0);
+ SAVE_ERRNO_AND_CLOSE(child_parent_fd);
+ if (err)
+ break;
+ }
+
+ btrfs_util_destroy_subvolume_iterator(iter);
+out:
+ SAVE_ERRNO_AND_CLOSE(fd);
+ return err;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_delete_subvolume(const char *path,
+ int flags)
+{
+ char name[BTRFS_PATH_NAME_MAX + 1];
+ enum btrfs_util_error err;
+ int parent_fd;
+
+ err = openat_parent_and_name(AT_FDCWD, path, name, sizeof(name),
+ &parent_fd);
+ if (err)
+ return err;
+
+ err = btrfs_util_delete_subvolume_fd(parent_fd, name, flags);
+ SAVE_ERRNO_AND_CLOSE(parent_fd);
+ return err;
+}
+
+PUBLIC enum btrfs_util_error btrfs_util_delete_subvolume_fd(int parent_fd,
+ const char *name,
+ int flags)
+{
+ struct btrfs_ioctl_vol_args args = {};
+ enum btrfs_util_error err;
+ size_t len;
+ int ret;
+
+ if (flags & ~BTRFS_UTIL_DELETE_SUBVOLUME_MASK) {
+ errno = EINVAL;
+ return BTRFS_UTIL_ERROR_INVALID_ARGUMENT;
+ }
+
+ if (flags & BTRFS_UTIL_DELETE_SUBVOLUME_RECURSIVE) {
+ err = delete_subvolume_children(parent_fd, name);
+ if (err)
+ return err;
+ }
+
+ len = strlen(name);
+ if (len >= sizeof(args.name)) {
+ errno = ENAMETOOLONG;
+ return BTRFS_UTIL_ERROR_INVALID_ARGUMENT;
+ }
+ memcpy(args.name, name, len);
+ args.name[len] = '\0';
+
+ ret = ioctl(parent_fd, BTRFS_IOC_SNAP_DESTROY, &args);
+ if (ret == -1)
+ return BTRFS_UTIL_ERROR_SNAP_DESTROY_FAILED;
+
+ return BTRFS_UTIL_OK;
+}
+
PUBLIC void btrfs_util_destroy_subvolume_iterator(struct btrfs_util_subvolume_iterator *iter)
{
if (iter) {