+++ /dev/null
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-
-#include <sys/file.h>
-#include <unistd.h>
-
-#include "alloc-util.h"
-#include "blockdev-util.h"
-#include "btrfs-util.h"
-#include "dirent-util.h"
-#include "fd-util.h"
-#include "fileio.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;
- 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 -errno;
-
- /* Get parent dev_t */
- xsprintf_sys_block_path(p, "/../dev", d);
- r = read_one_line_file(p, &s);
- if (r < 0)
- return r;
-
- 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", devt);
- if (access(p, F_OK) < 0)
- return -errno;
-
- *ret = devt;
- return 1;
-}
-
-int get_block_device(const char *path, dev_t *ret) {
- _cleanup_close_ int fd = -1;
- struct stat st;
- int r;
-
- assert(path);
- assert(ret);
-
- /* Gets the block device directly backing a file system. If the block device is encrypted, returns
- * the device mapper block device. */
-
- fd = open(path, O_RDONLY|O_NOFOLLOW|O_CLOEXEC);
- if (fd < 0)
- return -errno;
-
- if (fstat(fd, &st))
- return -errno;
-
- if (major(st.st_dev) != 0) {
- *ret = st.st_dev;
- return 1;
- }
-
- 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 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")];
- _cleanup_free_ char *first_found = NULL;
- struct dirent *de;
- const char *q;
- dev_t devt;
- int 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)
- return -errno;
-
- FOREACH_DIRENT_ALL(de, d, return -errno) {
-
- if (dot_or_dot_dot(de->d_name))
- continue;
-
- if (!IN_SET(de->d_type, DT_LNK, DT_UNKNOWN))
- continue;
-
- if (first_found) {
- _cleanup_free_ char *u = NULL, *v = NULL, *a = NULL, *b = NULL;
-
- /* We found a device backed by multiple other devices. We don't really support
- * automatic discovery on such setups, with the exception of dm-verity partitions. In
- * this case there are two backing devices: the data partition and the hash
- * partition. We are fine with such setups, however, only if both partitions are on
- * the same physical device. Hence, let's verify this by iterating over every node
- * in the 'slaves/' directory and comparing them with the first that gets returned by
- * readdir(), to ensure they all point to the same device. */
-
- u = path_join(p, de->d_name, "../dev");
- if (!u)
- return -ENOMEM;
-
- v = path_join(p, first_found, "../dev");
- if (!v)
- return -ENOMEM;
-
- r = read_one_line_file(u, &a);
- if (r < 0)
- return log_debug_errno(r, "Failed to read %s: %m", u);
-
- r = read_one_line_file(v, &b);
- 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))
- return -ENOTUNIQ;
- } else {
- first_found = strdup(de->d_name);
- if (!first_found)
- return -ENOMEM;
- }
- }
-
- if (!first_found)
- return -ENOENT;
-
- q = strjoina(p, "/", first_found, "/dev");
-
- r = read_one_line_file(q, &t);
- if (r < 0)
- return r;
-
- r = parse_dev(t, &devt);
- if (r < 0)
- return -EINVAL;
-
- if (major(devt) == 0)
- return -ENOENT;
-
- *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);
-
- 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