X-Git-Url: http://git.ipfire.org/?a=blobdiff_plain;f=src%2Fbasic%2Fblockdev-util.c;h=21ff3ba1b13c018ac283476216d308b12585b19b;hb=e8467cd31c9d5da28c31a6559fbe40ccb663fa7f;hp=b15b8cf7703c05b24cd8fe489e2d5b1f05bf60a0;hpb=2cb36f7c1e4672df2b47bffab3b7d65216915992;p=thirdparty%2Fsystemd.git diff --git a/src/basic/blockdev-util.c b/src/basic/blockdev-util.c index b15b8cf7703..21ff3ba1b13 100644 --- a/src/basic/blockdev-util.c +++ b/src/basic/blockdev-util.c @@ -1,12 +1,7 @@ /* SPDX-License-Identifier: LGPL-2.1+ */ -/*** - This file is part of systemd. - Copyright 2010 Lennart Poettering -***/ - -#include -#include +#include +#include #include "alloc-util.h" #include "blockdev-util.h" @@ -14,28 +9,34 @@ #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); @@ -43,76 +44,68 @@ int block_get_whole_disk(dev_t d, dev_t *ret) { 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) { @@ -131,56 +124,130 @@ int get_block_device_harder(const char *path, dev_t *dev) { * 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); +}