From cfe5e3905201349e9cf3f95d52ff4bd100bde37d Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 14 Apr 2024 21:10:49 +0200 Subject: Adding upstream version 2.39.3. Signed-off-by: Daniel Baumann --- libblkid/src/devname.c | 647 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 647 insertions(+) create mode 100644 libblkid/src/devname.c (limited to 'libblkid/src/devname.c') diff --git a/libblkid/src/devname.c b/libblkid/src/devname.c new file mode 100644 index 0000000..3f48032 --- /dev/null +++ b/libblkid/src/devname.c @@ -0,0 +1,647 @@ +/* + * devname.c - get a dev by its device inode name + * + * Copyright (C) Andries Brouwer + * Copyright (C) 1999, 2000, 2001, 2002, 2003 Theodore Ts'o + * Copyright (C) 2001 Andreas Dilger + * + * %Begin-Header% + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * %End-Header% + */ + +#define _GNU_SOURCE 1 + +#include +#include +#include +#ifdef HAVE_UNISTD_H +#include +#endif +#include +#include +#include +#ifdef HAVE_SYS_TYPES_H +#include +#endif +#include +#ifdef HAVE_SYS_STAT_H +#include +#endif +#ifdef HAVE_ERRNO_H +#include +#endif +#include + +#include "blkidP.h" + +#include "canonicalize.h" /* $(top_srcdir)/include */ +#include "pathnames.h" +#include "sysfs.h" +#include "fileutils.h" + +/* + * Find a dev struct in the cache by device name, if available. + * + * If there is no entry with the specified device name, and the create + * flag is set, then create an empty device entry. + */ +blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags) +{ + blkid_dev dev = NULL, tmp; + struct list_head *p, *pnext; + char *cn = NULL; + + if (!cache || !devname) + return NULL; + + /* search by name */ + list_for_each(p, &cache->bic_devs) { + tmp = list_entry(p, struct blkid_struct_dev, bid_devs); + if (strcmp(tmp->bid_name, devname) != 0) + continue; + dev = tmp; + break; + } + + /* try canonicalize the name */ + if (!dev && (cn = canonicalize_path(devname))) { + if (strcmp(cn, devname) != 0) { + DBG(DEVNAME, ul_debug("search canonical %s", cn)); + list_for_each(p, &cache->bic_devs) { + tmp = list_entry(p, struct blkid_struct_dev, bid_devs); + if (strcmp(tmp->bid_name, cn) != 0) + continue; + dev = tmp; + + /* update name returned by blkid_dev_devname() */ + free(dev->bid_xname); + dev->bid_xname = strdup(devname); + break; + } + } else { + free(cn); + cn = NULL; + } + } + + if (!dev && (flags & BLKID_DEV_CREATE)) { + if (access(devname, F_OK) < 0) + goto done; + dev = blkid_new_dev(); + if (!dev) + goto done; + dev->bid_time = (uintmax_t)1 << (sizeof(time_t) * 8 - 1); + if (cn) { + dev->bid_name = cn; + dev->bid_xname = strdup(devname); + cn = NULL; /* see free() below */ + } else + dev->bid_name = strdup(devname); + + dev->bid_cache = cache; + list_add_tail(&dev->bid_devs, &cache->bic_devs); + cache->bic_flags |= BLKID_BIC_FL_CHANGED; + } + + if (flags & BLKID_DEV_VERIFY) { + dev = blkid_verify(cache, dev); + if (!dev || !(dev->bid_flags & BLKID_BID_FL_VERIFIED)) + goto done; + /* + * If the device is verified, then search the blkid + * cache for any entries that match on the type, uuid, + * and label, and verify them; if a cache entry can + * not be verified, then it's stale and so we remove + * it. + */ + list_for_each_safe(p, pnext, &cache->bic_devs) { + blkid_dev dev2 = list_entry(p, struct blkid_struct_dev, bid_devs); + if (dev2->bid_flags & BLKID_BID_FL_VERIFIED) + continue; + if (!dev->bid_type || !dev2->bid_type || + strcmp(dev->bid_type, dev2->bid_type) != 0) + continue; + if (dev->bid_label && dev2->bid_label && + strcmp(dev->bid_label, dev2->bid_label) != 0) + continue; + if (dev->bid_uuid && dev2->bid_uuid && + strcmp(dev->bid_uuid, dev2->bid_uuid) != 0) + continue; + if ((dev->bid_label && !dev2->bid_label) || + (!dev->bid_label && dev2->bid_label) || + (dev->bid_uuid && !dev2->bid_uuid) || + (!dev->bid_uuid && dev2->bid_uuid)) + continue; + dev2 = blkid_verify(cache, dev2); + if (dev2 && !(dev2->bid_flags & BLKID_BID_FL_VERIFIED)) + blkid_free_dev(dev2); + } + } +done: + if (dev) + DBG(DEVNAME, ul_debug("%s requested, found %s in cache", devname, dev->bid_name)); + free(cn); + return dev; +} + +/* Directories where we will try to search for device names */ +static const char *dirlist[] = { "/dev", "/devfs", "/devices", NULL }; + +/* + * Return 1 if the device is a device-mapper 'leaf' node + * not holding any other devices in its hierarchy. + */ +static int is_dm_leaf(const char *devname) +{ + DIR *dir; + char path[NAME_MAX + 18 + 1]; + int ret; + + snprintf(path, sizeof(path), "/sys/block/%s/holders", devname); + if ((dir = opendir(path)) == NULL) + return 0; + + ret = xreaddir(dir) == NULL ? 1 : 0; /* 'leaf' has no entries */ + + closedir(dir); + return ret; +} + +/* + * Probe a single block device to add to the device cache. + */ +static void probe_one(blkid_cache cache, const char *ptname, + dev_t devno, int pri, int only_if_new, int removable) +{ + blkid_dev dev = NULL; + struct list_head *p, *pnext; + const char **dir; + char *devname = NULL; + + /* See if we already have this device number in the cache. */ + list_for_each_safe(p, pnext, &cache->bic_devs) { + blkid_dev tmp = list_entry(p, struct blkid_struct_dev, + bid_devs); + if (tmp->bid_devno == devno) { + if (only_if_new && !access(tmp->bid_name, F_OK)) + return; + dev = blkid_verify(cache, tmp); + if (dev && (dev->bid_flags & BLKID_BID_FL_VERIFIED)) + break; + dev = NULL; + } + } + if (dev && dev->bid_devno == devno) + goto set_pri; + + /* Try to translate private device-mapper dm- names + * to standard /dev/mapper/. + */ + if (!strncmp(ptname, "dm-", 3) && isdigit(ptname[3])) { + devname = canonicalize_dm_name(ptname); + if (!devname) + blkid__scan_dir("/dev/mapper", devno, NULL, &devname); + if (devname) + goto get_dev; + } + + /* + * Take a quick look at /dev/ptname for the device number. We check + * all of the likely device directories. If we don't find it, or if + * the stat information doesn't check out, use blkid_devno_to_devname() + * to find it via an exhaustive search for the device major/minor. + */ + for (dir = dirlist; *dir; dir++) { + struct stat st; + char device[256]; + + snprintf(device, sizeof(device), "%s/%s", *dir, ptname); + if ((dev = blkid_get_dev(cache, device, BLKID_DEV_FIND)) && + dev->bid_devno == devno) + goto set_pri; + + if (stat(device, &st) == 0 && + (S_ISBLK(st.st_mode) || + (S_ISCHR(st.st_mode) && !strncmp(ptname, "ubi", 3))) && + st.st_rdev == devno) { + devname = strdup(device); + goto get_dev; + } + } + /* Do a short-cut scan of /dev/mapper first */ + if (!devname) + blkid__scan_dir("/dev/mapper", devno, NULL, &devname); + if (!devname) { + devname = blkid_devno_to_devname(devno); + if (!devname) + return; + } + +get_dev: + dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL); + free(devname); + +set_pri: + if (dev) { + if (pri) + dev->bid_pri = pri; + else if (!strncmp(dev->bid_name, "/dev/mapper/", 12)) { + dev->bid_pri = BLKID_PRI_DM; + if (is_dm_leaf(ptname)) + dev->bid_pri += 5; + } else if (!strncmp(ptname, "md", 2)) + dev->bid_pri = BLKID_PRI_MD; + if (removable) + dev->bid_flags |= BLKID_BID_FL_REMOVABLE; + } +} + +#define PROC_PARTITIONS "/proc/partitions" +#define VG_DIR "/proc/lvm/VGs" + +/* + * This function initializes the UUID cache with devices from the LVM + * proc hierarchy. We currently depend on the names of the LVM + * hierarchy giving us the device structure in /dev. (XXX is this a + * safe thing to do?) + */ +#ifdef VG_DIR +static dev_t lvm_get_devno(const char *lvm_device) +{ + FILE *lvf; + char buf[1024]; + int ma, mi; + dev_t ret = 0; + + DBG(DEVNAME, ul_debug("opening %s", lvm_device)); + if ((lvf = fopen(lvm_device, "r" UL_CLOEXECSTR)) == NULL) { + DBG(DEVNAME, ul_debug("%s: (%d) %m", lvm_device, errno)); + return 0; + } + + while (fgets(buf, sizeof(buf), lvf)) { + if (sscanf(buf, "device: %d:%d", &ma, &mi) == 2) { + ret = makedev(ma, mi); + break; + } + } + fclose(lvf); + + return ret; +} + +static void lvm_probe_all(blkid_cache cache, int only_if_new) +{ + DIR *vg_list; + struct dirent *vg_iter; + int vg_len = strlen(VG_DIR); + dev_t dev; + + if ((vg_list = opendir(VG_DIR)) == NULL) + return; + + DBG(DEVNAME, ul_debug("probing LVM devices under %s", VG_DIR)); + + while ((vg_iter = readdir(vg_list)) != NULL) { + DIR *lv_list; + char *vdirname; + char *vg_name; + struct dirent *lv_iter; + size_t len; + + vg_name = vg_iter->d_name; + if (!strcmp(vg_name, ".") || !strcmp(vg_name, "..")) + continue; + len = vg_len + strlen(vg_name) + 8; + vdirname = malloc(len); + if (!vdirname) + goto exit; + snprintf(vdirname, len, "%s/%s/LVs", VG_DIR, vg_name); + + lv_list = opendir(vdirname); + free(vdirname); + if (lv_list == NULL) + continue; + + while ((lv_iter = readdir(lv_list)) != NULL) { + char *lv_name, *lvm_device; + + lv_name = lv_iter->d_name; + if (!strcmp(lv_name, ".") || !strcmp(lv_name, "..")) + continue; + + len = vg_len + strlen(vg_name) + strlen(lv_name) + 8; + lvm_device = malloc(len); + if (!lvm_device) { + closedir(lv_list); + goto exit; + } + snprintf(lvm_device, len, "%s/%s/LVs/%s", VG_DIR, vg_name, + lv_name); + dev = lvm_get_devno(lvm_device); + snprintf(lvm_device, len, "%s/%s", vg_name, lv_name); + DBG(DEVNAME, ul_debug("Probe LVM dev %s: devno 0x%04X", + lvm_device, + (unsigned int) dev)); + probe_one(cache, lvm_device, dev, BLKID_PRI_LVM, + only_if_new, 0); + free(lvm_device); + } + closedir(lv_list); + } +exit: + closedir(vg_list); +} +#endif + +static void +ubi_probe_all(blkid_cache cache, int only_if_new) +{ + const char **dirname; + + for (dirname = dirlist; *dirname; dirname++) { + DIR *dir; + struct dirent *iter; + + DBG(DEVNAME, ul_debug("probing UBI volumes under %s", + *dirname)); + + dir = opendir(*dirname); + if (dir == NULL) + continue ; + + while ((iter = readdir(dir)) != NULL) { + char *name; + struct stat st; + dev_t dev; + + name = iter->d_name; +#ifdef _DIRENT_HAVE_D_TYPE + if (iter->d_type != DT_UNKNOWN && + iter->d_type != DT_CHR && iter->d_type != DT_LNK) + continue; +#endif + if (!strcmp(name, ".") || !strcmp(name, "..") || + !strstr(name, "ubi")) + continue; + if (!strcmp(name, "ubi_ctrl")) + continue; + if (fstatat(dirfd(dir), name, &st, 0)) + continue; + + dev = st.st_rdev; + + if (!S_ISCHR(st.st_mode) || !minor(dev)) + continue; + DBG(DEVNAME, ul_debug("Probe UBI vol %s/%s: devno 0x%04X", + *dirname, name, (int) dev)); + probe_one(cache, name, dev, BLKID_PRI_UBI, only_if_new, 0); + } + closedir(dir); + } +} + +/* + * This function uses /sys to read all block devices in way compatible with + * /proc/partitions (like the original libblkid implementation) + */ +static int +sysfs_probe_all(blkid_cache cache, int only_if_new, int only_removable) +{ + DIR *sysfs; + struct dirent *dev; + + sysfs = opendir(_PATH_SYS_BLOCK); + if (!sysfs) + return -BLKID_ERR_SYSFS; + + DBG(DEVNAME, ul_debug(" probe /sys/block")); + + /* scan /sys/block */ + while ((dev = xreaddir(sysfs))) { + DIR *dir = NULL; + dev_t devno; + size_t nparts = 0; + unsigned int maxparts = 0, removable = 0; + struct dirent *part; + struct path_cxt *pc = NULL; + uint64_t size = 0; + + DBG(DEVNAME, ul_debug("checking %s", dev->d_name)); + + devno = sysfs_devname_to_devno(dev->d_name); + if (!devno) + goto next; + pc = ul_new_sysfs_path(devno, NULL, NULL); + if (!pc) + goto next; + + if (ul_path_read_u64(pc, &size, "size") != 0) + size = 0; + if (ul_path_read_u32(pc, &removable, "removable") != 0) + removable = 0; + + /* ignore empty devices */ + if (!size) + goto next; + + /* accept removable if only removable requested */ + if (only_removable) { + if (!removable) + goto next; + + /* emulate /proc/partitions + * -- ignore empty devices and non-partitionable removable devices */ + } else { + if (ul_path_read_u32(pc, &maxparts, "ext_range") != 0) + maxparts = 0; + if (!maxparts && removable) + goto next; + } + + DBG(DEVNAME, ul_debug("read device name %s", dev->d_name)); + + dir = ul_path_opendir(pc, NULL); + if (!dir) + goto next; + + /* read /sys/block// do get partitions */ + while ((part = xreaddir(dir))) { + dev_t partno; + + if (!sysfs_blkdev_is_partition_dirent(dir, part, dev->d_name)) + continue; + + /* ignore extended partitions + * -- recount size to blocks like /proc/partitions */ + if (ul_path_readf_u64(pc, &size, "%s/size", part->d_name) == 0 + && (size >> 1) == 1) + continue; + partno = __sysfs_devname_to_devno(NULL, part->d_name, dev->d_name); + if (!partno) + continue; + + DBG(DEVNAME, ul_debug(" Probe partition dev %s, devno 0x%04X", + part->d_name, (unsigned int) partno)); + nparts++; + probe_one(cache, part->d_name, partno, 0, only_if_new, 0); + } + + if (!nparts) { + /* add non-partitioned whole disk to cache */ + DBG(DEVNAME, ul_debug(" Probe whole dev %s, devno 0x%04X", + dev->d_name, (unsigned int) devno)); + probe_one(cache, dev->d_name, devno, 0, only_if_new, 0); + } else { + /* remove partitioned whole-disk from cache */ + struct list_head *p, *pnext; + + list_for_each_safe(p, pnext, &cache->bic_devs) { + blkid_dev tmp = list_entry(p, struct blkid_struct_dev, + bid_devs); + if (tmp->bid_devno == devno) { + DBG(DEVNAME, ul_debug(" freeing %s", tmp->bid_name)); + blkid_free_dev(tmp); + cache->bic_flags |= BLKID_BIC_FL_CHANGED; + break; + } + } + } + next: + if (dir) + closedir(dir); + if (pc) + ul_unref_path(pc); + } + + closedir(sysfs); + return 0; +} + +/* + * Read the device data for all available block devices in the system. + */ +static int probe_all(blkid_cache cache, int only_if_new, int update_interval) +{ + int rc; + + if (!cache) + return -BLKID_ERR_PARAM; + + if (cache->bic_flags & BLKID_BIC_FL_PROBED && + time(NULL) - cache->bic_time < BLKID_PROBE_INTERVAL) { + DBG(PROBE, ul_debug("don't re-probe [delay < %d]", BLKID_PROBE_INTERVAL)); + return 0; + } + + blkid_read_cache(cache); +#ifdef VG_DIR + lvm_probe_all(cache, only_if_new); +#endif + ubi_probe_all(cache, only_if_new); + + rc = sysfs_probe_all(cache, only_if_new, 0); + + /* Don't mark the change as "probed" if /sys not avalable */ + if (update_interval && rc == 0) { + cache->bic_time = time(NULL); + cache->bic_flags |= BLKID_BIC_FL_PROBED; + } + + blkid_flush_cache(cache); + return 0; +} + +/** + * blkid_probe_all: + * @cache: cache handler + * + * Probes all block devices. + * + * Returns: 0 on success, or number less than zero in case of error. + */ +int blkid_probe_all(blkid_cache cache) +{ + int ret; + + DBG(PROBE, ul_debug("Begin blkid_probe_all()")); + ret = probe_all(cache, 0, 1); + DBG(PROBE, ul_debug("End blkid_probe_all() [rc=%d]", ret)); + return ret; +} + +/** + * blkid_probe_all_new: + * @cache: cache handler + * + * Probes all new block devices. + * + * Returns: 0 on success, or number less than zero in case of error. + */ +int blkid_probe_all_new(blkid_cache cache) +{ + int ret; + + DBG(PROBE, ul_debug("Begin blkid_probe_all_new()")); + ret = probe_all(cache, 1, 0); + DBG(PROBE, ul_debug("End blkid_probe_all_new() [rc=%d]", ret)); + return ret; +} + +/** + * blkid_probe_all_removable: + * @cache: cache handler + * + * The libblkid probing is based on devices from /proc/partitions by default. + * This file usually does not contain removable devices (e.g. CDROMs) and this kind + * of devices are invisible for libblkid. + * + * This function adds removable block devices to @cache (probing is based on + * information from the /sys directory). Don't forget that removable devices + * (floppies, CDROMs, ...) could be pretty slow. It's very bad idea to call + * this function by default. + * + * Note that devices which were detected by this function won't be written to + * blkid.tab cache file. + * + * Returns: 0 on success, or number less than zero in case of error. + */ +int blkid_probe_all_removable(blkid_cache cache) +{ + int ret; + + DBG(PROBE, ul_debug("Begin blkid_probe_all_removable()")); + ret = sysfs_probe_all(cache, 0, 1); + DBG(PROBE, ul_debug("End blkid_probe_all_removable() [rc=%d]", ret)); + return ret; +} + +#ifdef TEST_PROGRAM +int main(int argc, char **argv) +{ + blkid_cache cache = NULL; + int ret; + + blkid_init_debug(BLKID_DEBUG_ALL); + if (argc != 1) { + fprintf(stderr, "Usage: %s\n" + "Probe all devices and exit\n", argv[0]); + exit(1); + } + if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) { + fprintf(stderr, "%s: error creating cache (%d)\n", + argv[0], ret); + exit(1); + } + if (blkid_probe_all(cache) < 0) + printf("%s: error probing devices\n", argv[0]); + + if (blkid_probe_all_removable(cache) < 0) + printf("%s: error probing removable devices\n", argv[0]); + + blkid_put_cache(cache); + return (0); +} +#endif -- cgit v1.2.3