diff options
| -rw-r--r-- | src/gpt-auto-generator/gpt-auto-generator.c | 79 |
1 files changed, 77 insertions, 2 deletions
diff --git a/src/gpt-auto-generator/gpt-auto-generator.c b/src/gpt-auto-generator/gpt-auto-generator.c index 0a34f86be7..2ab7257a24 100644 --- a/src/gpt-auto-generator/gpt-auto-generator.c +++ b/src/gpt-auto-generator/gpt-auto-generator.c @@ -799,6 +799,10 @@ static int get_block_device(const char *path, dev_t *dev) { assert(path); assert(dev); + /* Get's the block device directly backing a file system. If + * the block device is encrypted, returns the device mapper + * block device. */ + if (lstat(path, &st)) return -errno; @@ -816,6 +820,77 @@ static int get_block_device(const char *path, dev_t *dev) { return 0; } +static int get_block_device_harder(const char *path, dev_t *dev) { + _cleanup_closedir_ DIR *d = NULL; + _cleanup_free_ char *p = NULL, *t = NULL; + struct dirent *de, *found = NULL; + const char *q; + unsigned maj, min; + dev_t dt; + 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; + + if (asprintf(&p, "/sys/dev/block/%u:%u/slaves", major(dt), minor(dt)) < 0) + return -ENOMEM; + + d = opendir(p); + if (!d) { + if (errno == ENOENT) + goto fallback; + + return -errno; + } + + FOREACH_DIRENT_ALL(de, d, return -errno) { + + if (STR_IN_SET(de->d_name, ".", "..")) + continue; + + if (!IN_SET(de->d_type, DT_LNK, DT_UNKNOWN)) + continue; + + if (found) /* Don't try to support multiple backing block devices */ + goto fallback; + + found = de; + break; + } + + if (!found) + goto fallback; + + 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) + return -EINVAL; + + if (maj == 0) + goto fallback; + + *dev = makedev(maj, min); + return 1; + +fallback: + *dev = dt; + return 1; +} + static int parse_proc_cmdline_item(const char *key, const char *value) { int r; @@ -883,11 +958,11 @@ static int add_mounts(void) { dev_t devno; int r; - r = get_block_device("/", &devno); + r = get_block_device_harder("/", &devno); if (r < 0) return log_error_errno(r, "Failed to determine block device of root file system: %m"); else if (r == 0) { - r = get_block_device("/usr", &devno); + r = get_block_device_harder("/usr", &devno); if (r < 0) return log_error_errno(r, "Failed to determine block device of /usr file system: %m"); else if (r == 0) { |