-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#include <errno.h>
+#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include "chattr-util.h"
+#include "errno-util.h"
#include "fd-util.h"
-#include "util.h"
-
-int chattr_fd(int fd, unsigned value, unsigned mask) {
+#include "macro.h"
+#include "string-util.h"
+
+int chattr_full(const char *path,
+ int fd,
+ unsigned value,
+ unsigned mask,
+ unsigned *ret_previous,
+ unsigned *ret_final,
+ ChattrApplyFlags flags) {
+
+ _cleanup_close_ int fd_will_close = -EBADF;
unsigned old_attr, new_attr;
+ int set_flags_errno = 0;
struct stat st;
- assert(fd >= 0);
+ assert(path || fd >= 0);
+
+ if (fd < 0) {
+ fd = fd_will_close = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
+ if (fd < 0)
+ return -errno;
+ }
if (fstat(fd, &st) < 0)
return -errno;
- /* Explicitly check whether this is a regular file or
- * directory. If it is anything else (such as a device node or
- * fifo), then the ioctl will not hit the file systems but
- * possibly drivers, where the ioctl might have different
- * effects. Notably, DRM is using the same ioctl() number. */
+ /* Explicitly check whether this is a regular file or directory. If it is anything else (such
+ * as a device node or fifo), then the ioctl will not hit the file systems but possibly
+ * drivers, where the ioctl might have different effects. Notably, DRM is using the same
+ * ioctl() number. */
if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
return -ENOTTY;
- if (mask == 0)
+ if (mask == 0 && !ret_previous && !ret_final)
return 0;
if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0)
return -errno;
new_attr = (old_attr & ~mask) | (value & mask);
- if (new_attr == old_attr)
+ if (new_attr == old_attr) {
+ if (ret_previous)
+ *ret_previous = old_attr;
+ if (ret_final)
+ *ret_final = old_attr;
return 0;
+ }
- if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0)
- return -errno;
+ if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) >= 0) {
+ unsigned attr;
- return 1;
-}
+ /* Some filesystems (BTRFS) silently fail when a flag cannot be set. Let's make sure our
+ * changes actually went through by querying the flags again and verifying they're equal to
+ * the flags we tried to configure. */
-int chattr_path(const char *p, unsigned value, unsigned mask) {
- _cleanup_close_ int fd = -1;
+ if (ioctl(fd, FS_IOC_GETFLAGS, &attr) < 0)
+ return -errno;
- assert(p);
+ if (new_attr == attr) {
+ if (ret_previous)
+ *ret_previous = old_attr;
+ if (ret_final)
+ *ret_final = new_attr;
+ return 1;
+ }
- if (mask == 0)
- return 0;
+ /* Trigger the fallback logic. */
+ errno = EINVAL;
+ }
- fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
- if (fd < 0)
+ if ((errno != EINVAL && !ERRNO_IS_NOT_SUPPORTED(errno)) ||
+ !FLAGS_SET(flags, CHATTR_FALLBACK_BITWISE))
return -errno;
- return chattr_fd(fd, value, mask);
+ /* When -EINVAL is returned, we assume that incompatible attributes are simultaneously
+ * specified. E.g., compress(c) and nocow(C) attributes cannot be set to files on btrfs.
+ * As a fallback, let's try to set attributes one by one.
+ *
+ * Also, when we get EOPNOTSUPP (or a similar error code) we assume a flag might just not be
+ * supported, and we can ignore it too */
+
+ unsigned current_attr = old_attr;
+ for (unsigned i = 0; i < sizeof(unsigned) * 8; i++) {
+ unsigned new_one, mask_one = 1u << i;
+
+ if (!FLAGS_SET(mask, mask_one))
+ continue;
+
+ new_one = UPDATE_FLAG(current_attr, mask_one, FLAGS_SET(value, mask_one));
+ if (new_one == current_attr)
+ continue;
+
+ if (ioctl(fd, FS_IOC_SETFLAGS, &new_one) < 0) {
+ if (errno != EINVAL && !ERRNO_IS_NOT_SUPPORTED(errno))
+ return -errno;
+
+ log_full_errno(FLAGS_SET(flags, CHATTR_WARN_UNSUPPORTED_FLAGS) ? LOG_WARNING : LOG_DEBUG,
+ errno,
+ "Unable to set file attribute 0x%x on %s, ignoring: %m", mask_one, strna(path));
+
+ /* Ensures that we record whether only EOPNOTSUPP&friends are encountered, or if a more serious
+ * error (thus worth logging at a different level, etc) was seen too. */
+ if (set_flags_errno == 0 || !ERRNO_IS_NOT_SUPPORTED(errno))
+ set_flags_errno = -errno;
+
+ continue;
+ }
+
+ if (ioctl(fd, FS_IOC_GETFLAGS, ¤t_attr) < 0)
+ return -errno;
+ }
+
+ if (ret_previous)
+ *ret_previous = old_attr;
+ if (ret_final)
+ *ret_final = current_attr;
+
+ /* -ENOANO indicates that some attributes cannot be set. ERRNO_IS_NOT_SUPPORTED indicates that all
+ * encountered failures were due to flags not supported by the FS, so return a specific error in
+ * that case, so callers can handle it properly (e.g.: tmpfiles.d can use debug level logging). */
+ return current_attr == new_attr ? 1 : ERRNO_IS_NOT_SUPPORTED(set_flags_errno) ? set_flags_errno : -ENOANO;
}
int read_attr_fd(int fd, unsigned *ret) {
if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode))
return -ENOTTY;
- if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0)
- return -errno;
-
- return 0;
+ return RET_NERRNO(ioctl(fd, FS_IOC_GETFLAGS, ret));
}
int read_attr_path(const char *p, unsigned *ret) {
- _cleanup_close_ int fd = -1;
+ _cleanup_close_ int fd = -EBADF;
assert(p);
assert(ret);
projects / thirdparty / systemd.git / blobdiff