/* SPDX-License-Identifier: LGPL-2.1+ */
-/***
- This file is part of systemd.
- Copyright 2010 Lennart Poettering
-***/
-
-#include <sys/stat.h>
-#include <sys/statfs.h>
+#include <sys/file.h>
+#include <unistd.h>
#include "alloc-util.h"
#include "blockdev-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "fileio.h"
-#include "missing.h"
+#include "missing_magic.h"
+#include "parse-util.h"
#include "stat-util.h"
int block_get_whole_disk(dev_t d, dev_t *ret) {
char p[SYS_BLOCK_PATH_MAX("/partition")];
_cleanup_free_ char *s = NULL;
- unsigned n, m;
+ dev_t devt;
int r;
assert(ret);
+ if (major(d) == 0)
+ return -ENODEV;
+
/* If it has a queue this is good enough for us */
xsprintf_sys_block_path(p, "/queue", d);
if (access(p, F_OK) >= 0) {
*ret = d;
return 0;
}
+ if (errno != ENOENT)
+ return -errno;
/* If it is a partition find the originating device */
xsprintf_sys_block_path(p, "/partition", d);
if (access(p, F_OK) < 0)
- return -ENOENT;
+ return -errno;
/* Get parent dev_t */
xsprintf_sys_block_path(p, "/../dev", d);
if (r < 0)
return r;
- r = sscanf(s, "%u:%u", &m, &n);
- if (r != 2)
- return -EINVAL;
+ r = parse_dev(s, &devt);
+ if (r < 0)
+ return r;
/* Only return this if it is really good enough for us. */
- xsprintf_sys_block_path(p, "/queue", makedev(m, n));
+ xsprintf_sys_block_path(p, "/queue", devt);
if (access(p, F_OK) < 0)
- return -ENOENT;
+ return -errno;
- *ret = makedev(m, n);
- return 0;
+ *ret = devt;
+ return 1;
}
-int get_block_device(const char *path, dev_t *dev) {
+int get_block_device(const char *path, dev_t *ret) {
+ _cleanup_close_ int fd = -1;
struct stat st;
- struct statfs sfs;
+ int r;
assert(path);
- assert(dev);
+ assert(ret);
- /* Get's the block device directly backing a file system. If
- * the block device is encrypted, returns the device mapper
- * block device. */
+ /* Gets the block device directly backing a file system. If the block device is encrypted, returns
+ * the device mapper block device. */
- if (lstat(path, &st))
+ fd = open(path, O_NOFOLLOW|O_CLOEXEC);
+ if (fd < 0)
+ return -errno;
+
+ if (fstat(fd, &st))
return -errno;
if (major(st.st_dev) != 0) {
- *dev = st.st_dev;
+ *ret = st.st_dev;
return 1;
}
- if (statfs(path, &sfs) < 0)
- return -errno;
-
- if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC))
- return btrfs_get_block_device(path, dev);
+ r = btrfs_get_block_device_fd(fd, ret);
+ if (r > 0)
+ return 1;
+ if (r != -ENOTTY) /* not btrfs */
+ return r;
+ *ret = 0;
return 0;
}
-int get_block_device_harder(const char *path, dev_t *dev) {
+int block_get_originating(dev_t dt, dev_t *ret) {
_cleanup_closedir_ DIR *d = NULL;
_cleanup_free_ char *t = NULL;
char p[SYS_BLOCK_PATH_MAX("/slaves")];
struct dirent *de, *found = NULL;
const char *q;
- unsigned maj, min;
- dev_t dt;
+ dev_t devt;
int r;
- assert(path);
- assert(dev);
-
- /* Gets the backing block device for a file system, and
- * handles LUKS encrypted file systems, looking for its
- * immediate parent, if there is one. */
-
- r = get_block_device(path, &dt);
- if (r <= 0)
- return r;
+ /* For the specified block device tries to chase it through the layers, in case LUKS-style DM stacking is used,
+ * trying to find the next underlying layer. */
xsprintf_sys_block_path(p, "/slaves", dt);
d = opendir(p);
- if (!d) {
- if (errno == ENOENT)
- goto fallback;
-
+ if (!d)
return -errno;
- }
FOREACH_DIRENT_ALL(de, d, return -errno) {
* setups, however, only if both partitions are on the same physical device. Hence, let's
* verify this. */
- u = strjoin(p, "/", de->d_name, "/../dev");
+ u = path_join(p, de->d_name, "../dev");
if (!u)
return -ENOMEM;
- v = strjoin(p, "/", found->d_name, "/../dev");
+ v = path_join(p, found->d_name, "../dev");
if (!v)
return -ENOMEM;
r = read_one_line_file(u, &a);
- if (r < 0) {
- log_debug_errno(r, "Failed to read %s: %m", u);
- goto fallback;
- }
+ if (r < 0)
+ return log_debug_errno(r, "Failed to read %s: %m", u);
r = read_one_line_file(v, &b);
- if (r < 0) {
- log_debug_errno(r, "Failed to read %s: %m", v);
- goto fallback;
- }
+ if (r < 0)
+ return log_debug_errno(r, "Failed to read %s: %m", v);
/* Check if the parent device is the same. If not, then the two backing devices are on
* different physical devices, and we don't support that. */
if (!streq(a, b))
- goto fallback;
+ return -ENOTUNIQ;
}
found = de;
}
if (!found)
- goto fallback;
+ return -ENOENT;
q = strjoina(p, "/", found->d_name, "/dev");
r = read_one_line_file(q, &t);
- if (r == -ENOENT)
- goto fallback;
if (r < 0)
return r;
- if (sscanf(t, "%u:%u", &maj, &min) != 2)
+ r = parse_dev(t, &devt);
+ if (r < 0)
return -EINVAL;
- if (maj == 0)
- goto fallback;
+ if (major(devt) == 0)
+ return -ENOENT;
- *dev = makedev(maj, min);
+ *ret = devt;
return 1;
+}
+
+int get_block_device_harder(const char *path, dev_t *ret) {
+ int r;
+
+ assert(path);
+ assert(ret);
+
+ /* Gets the backing block device for a file system, and handles LUKS encrypted file systems, looking for its
+ * immediate parent, if there is one. */
+
+ r = get_block_device(path, ret);
+ if (r <= 0)
+ return r;
+
+ r = block_get_originating(*ret, ret);
+ if (r < 0)
+ log_debug_errno(r, "Failed to chase block device '%s', ignoring: %m", path);
-fallback:
- *dev = dt;
return 1;
}
+
+int lock_whole_block_device(dev_t devt, int operation) {
+ _cleanup_free_ char *whole_node = NULL;
+ _cleanup_close_ int lock_fd = -1;
+ dev_t whole_devt;
+ int r;
+
+ /* Let's get a BSD file lock on the whole block device, as per: https://systemd.io/BLOCK_DEVICE_LOCKING */
+
+ r = block_get_whole_disk(devt, &whole_devt);
+ if (r < 0)
+ return r;
+
+ r = device_path_make_major_minor(S_IFBLK, whole_devt, &whole_node);
+ if (r < 0)
+ return r;
+
+ lock_fd = open(whole_node, O_RDONLY|O_CLOEXEC|O_NONBLOCK);
+ if (lock_fd < 0)
+ return -errno;
+
+ if (flock(lock_fd, operation) < 0)
+ return -errno;
+
+ return TAKE_FD(lock_fd);
+}
+
+int blockdev_partscan_enabled(int fd) {
+ _cleanup_free_ char *p = NULL, *buf = NULL;
+ unsigned long long ull;
+ struct stat st;
+ int r;
+
+ /* Checks if partition scanning is correctly enabled on the block device */
+
+ if (fstat(fd, &st) < 0)
+ return -errno;
+
+ if (!S_ISBLK(st.st_mode))
+ return -ENOTBLK;
+
+ if (asprintf(&p, "/sys/dev/block/%u:%u/capability", major(st.st_rdev), minor(st.st_rdev)) < 0)
+ return -ENOMEM;
+
+ r = read_one_line_file(p, &buf);
+ if (r == -ENOENT) /* If the capability file doesn't exist then we are most likely looking at a
+ * partition block device, not the whole block device. And that means we have no
+ * partition scanning on for it (we do for its parent, but not for the partition
+ * itself). */
+ return false;
+ if (r < 0)
+ return r;
+
+ r = safe_atollu_full(buf, 16, &ull);
+ if (r < 0)
+ return r;
+
+#ifndef GENHD_FL_NO_PART_SCAN
+#define GENHD_FL_NO_PART_SCAN (0x0200)
+#endif
+
+ return !FLAGS_SET(ull, GENHD_FL_NO_PART_SCAN);
+}
projects / thirdparty / systemd.git / blobdiff