-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <linux/fs.h>
+#include <linux/loop.h>
+#include <stddef.h>
+#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
#include <sys/stat.h>
-#include <sys/vfs.h>
-#ifdef HAVE_LINUX_BTRFS_H
+#include <sys/statfs.h>
+#include <sys/sysmacros.h>
+#include <unistd.h>
+
+#if HAVE_LINUX_BTRFS_H
#include <linux/btrfs.h>
#endif
#include "alloc-util.h"
#include "btrfs-ctree.h"
#include "btrfs-util.h"
+#include "chattr-util.h"
#include "copy.h"
#include "fd-util.h"
#include "fileio.h"
+#include "io-util.h"
#include "macro.h"
#include "missing.h"
#include "path-util.h"
+#include "rm-rf.h"
#include "selinux-util.h"
#include "smack-util.h"
+#include "sparse-endian.h"
#include "stat-util.h"
#include "string-util.h"
+#include "time-util.h"
#include "util.h"
/* WARNING: Be careful with file system ioctls! When we get an fd, we
return F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC);
}
-int btrfs_is_subvol(int fd) {
+int btrfs_is_subvol_fd(int fd) {
struct stat st;
assert(fd >= 0);
return btrfs_is_filesystem(fd);
}
+int btrfs_is_subvol(const char *path) {
+ _cleanup_close_ int fd = -1;
+
+ assert(path);
+
+ fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ if (fd < 0)
+ return -errno;
+
+ return btrfs_is_subvol_fd(fd);
+}
+
int btrfs_subvol_make(const char *path) {
struct btrfs_ioctl_vol_args args = {};
_cleanup_close_ int fd = -1;
unsigned i;
args.key.nr_items = 256;
- if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+ if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+ if (errno == ENOENT) /* quota tree is missing: quota disabled */
+ break;
+
return -errno;
+ }
if (args.key.nr_items <= 0)
break;
dev_t dev = 0;
int r;
+ /* In contrast to btrfs quota ioctls ftruncate() cannot make sense of "infinity" or file sizes > 2^31 */
+ if (!FILE_SIZE_VALID(new_size))
+ return -EINVAL;
+
/* btrfs cannot handle file systems < 16M, hence use this as minimum */
if (new_size < 16*1024*1024)
new_size = 16*1024*1024;
for (c = 0;; c++) {
if (ioctl(fd, BTRFS_IOC_QGROUP_CREATE, &args) < 0) {
+ /* If quota is not enabled, we get EINVAL. Turn this into a recognizable error */
+ if (errno == EINVAL)
+ return -ENOPROTOOPT;
+
if (errno == EBUSY && c < 10) {
(void) btrfs_quota_scan_wait(fd);
continue;
if (!S_ISDIR(st.st_mode))
return -EINVAL;
- subvol_fd = openat(fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ subvol_fd = openat(fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
if (subvol_fd < 0)
return -errno;
* hence we need to open the
* containing directory first */
- child_fd = openat(subvol_fd, ino_args.name, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ child_fd = openat(subvol_fd, ino_args.name, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
if (child_fd < 0)
return -errno;
unsigned i;
args.key.nr_items = 256;
- if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+ if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+ if (errno == ENOENT) /* quota tree missing: quota is not enabled, hence nothing to copy */
+ break;
+
return -errno;
+ }
if (args.key.nr_items <= 0)
break;
return n_old_qgroups;
r = btrfs_subvol_get_parent(fd, old_subvol_id, &old_parent_id);
- if (r < 0)
+ if (r == -ENXIO)
+ /* We have no parent, hence nothing to copy. */
+ n_old_parent_qgroups = 0;
+ else if (r < 0)
return r;
-
- n_old_parent_qgroups = btrfs_qgroup_find_parents(fd, old_parent_id, &old_parent_qgroups);
- if (n_old_parent_qgroups < 0)
- return n_old_parent_qgroups;
+ else {
+ n_old_parent_qgroups = btrfs_qgroup_find_parents(fd, old_parent_id, &old_parent_qgroups);
+ if (n_old_parent_qgroups < 0)
+ return n_old_parent_qgroups;
+ }
for (i = 0; i < n_old_qgroups; i++) {
uint64_t id;
if (!c)
return -ENOMEM;
- old_child_fd = openat(old_fd, c, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ old_child_fd = openat(old_fd, c, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
if (old_child_fd < 0)
return -errno;
- np = strjoin(subvolume, "/", ino_args.name, NULL);
+ np = strjoin(subvolume, "/", ino_args.name);
if (!np)
return -ENOMEM;
- new_child_fd = openat(new_fd, np, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ new_child_fd = openat(new_fd, np, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
if (new_child_fd < 0)
return -errno;
* into place. */
if (subvolume_fd < 0) {
- subvolume_fd = openat(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ subvolume_fd = openat(new_fd, subvolume, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY|O_NOFOLLOW);
if (subvolume_fd < 0)
return -errno;
}
assert(old_fd >= 0);
assert(new_path);
- r = btrfs_is_subvol(old_fd);
+ r = btrfs_is_subvol_fd(old_fd);
if (r < 0)
return r;
if (r == 0) {
+ bool plain_directory = false;
+
+ /* If the source isn't a proper subvolume, fail unless fallback is requested */
if (!(flags & BTRFS_SNAPSHOT_FALLBACK_COPY))
return -EISDIR;
r = btrfs_subvol_make(new_path);
- if (r < 0)
- return r;
+ if (r == -ENOTTY && (flags & BTRFS_SNAPSHOT_FALLBACK_DIRECTORY)) {
+ /* If the destination doesn't support subvolumes, then use a plain directory, if that's requested. */
+ if (mkdir(new_path, 0755) < 0)
+ return r;
- r = copy_directory_fd(old_fd, new_path, true);
- if (r < 0) {
- (void) btrfs_subvol_remove(new_path, BTRFS_REMOVE_QUOTA);
+ plain_directory = true;
+ } else if (r < 0)
return r;
- }
+
+ r = copy_directory_fd(old_fd, new_path, COPY_MERGE|COPY_REFLINK);
+ if (r < 0)
+ goto fallback_fail;
if (flags & BTRFS_SNAPSHOT_READ_ONLY) {
- r = btrfs_subvol_set_read_only(new_path, true);
- if (r < 0) {
- (void) btrfs_subvol_remove(new_path, BTRFS_REMOVE_QUOTA);
- return r;
+
+ if (plain_directory) {
+ /* Plain directories have no recursive read-only flag, but something pretty close to
+ * it: the IMMUTABLE bit. Let's use this here, if this is requested. */
+
+ if (flags & BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE)
+ (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL);
+ } else {
+ r = btrfs_subvol_set_read_only(new_path, true);
+ if (r < 0)
+ goto fallback_fail;
}
}
return 0;
+
+ fallback_fail:
+ (void) rm_rf(new_path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+ return r;
}
r = extract_subvolume_name(new_path, &subvolume);
unsigned i;
args.key.nr_items = 256;
- if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
+ if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0) {
+ if (errno == ENOENT) /* quota tree missing: quota is disabled */
+ break;
+
return -errno;
+ }
if (args.key.nr_items <= 0)
break;
*/
if (subvol_id == 0) {
- r = btrfs_is_subvol(fd);
+ r = btrfs_is_subvol_fd(fd);
if (r < 0)
return r;
if (!r)
if (n > 0) /* already parent qgroups set up, let's bail */
return 0;
+ qgroups = mfree(qgroups);
+
r = btrfs_subvol_get_parent(fd, subvol_id, &parent_subvol);
- if (r < 0)
+ if (r == -ENXIO)
+ /* No parent, hence no qgroup memberships */
+ n = 0;
+ else if (r < 0)
return r;
-
- qgroups = mfree(qgroups);
- n = btrfs_qgroup_find_parents(fd, parent_subvol, &qgroups);
- if (n < 0)
- return n;
+ else {
+ n = btrfs_qgroup_find_parents(fd, parent_subvol, &qgroups);
+ if (n < 0)
+ return n;
+ }
if (insert_intermediary_qgroup) {
uint64_t lowest = 256, new_qgroupid;
args.key.nr_items = 256;
if (ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args) < 0)
- return -errno;
+ return negative_errno();
if (args.key.nr_items <= 0)
break;
projects / thirdparty / systemd.git / blobdiff