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master
lib/blkid/devname.c
561 строка
14 KB
Theodore Ts'o
libblkid: fix gcc -Wall warnings
31 июл 2019, 04:13
31 июл 2019, 04:13
7525e8b
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/* * 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 "config.h" #include <stdio.h> #include <string.h> #include <limits.h> #if HAVE_UNISTD_H #include <unistd.h> #endif #include <stdlib.h> #include <string.h> #include <ctype.h> #if HAVE_SYS_TYPES_H #include <sys/types.h> #endif #include <dirent.h> #if HAVE_SYS_STAT_H #include <sys/stat.h> #endif #if HAVE_ERRNO_H #include <errno.h> #endif #if HAVE_SYS_MKDEV_H #include <sys/mkdev.h> #endif #ifdef HAVE_SYS_SYSMACROS_H #include <sys/sysmacros.h> #endif #include <time.h> #include "blkidP.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; if (!cache || !devname) return NULL; list_for_each(p, &cache->bic_devs) { tmp = list_entry(p, struct blkid_struct_dev, bid_devs); if (strcmp(tmp->bid_name, devname)) continue; DBG(DEBUG_DEVNAME, printf("found devname %s in cache\n", tmp->bid_name)); dev = tmp; break; } if (!dev && (flags & BLKID_DEV_CREATE)) { if (access(devname, F_OK) < 0) return NULL; dev = blkid_new_dev(); if (!dev) return NULL; dev->bid_time = INT_MIN; dev->bid_name = blkid_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)) return dev; /* * 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; 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)) continue; if (dev->bid_label && dev2->bid_label && strcmp(dev->bid_label, dev2->bid_label)) continue; if (dev->bid_uuid && dev2->bid_uuid && strcmp(dev->bid_uuid, dev2->bid_uuid)) 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); } } return dev; } /* Directories where we will try to search for device names */ static const char *dirlist[] = { "/dev", "/devfs", "/devices", NULL }; static int is_dm_leaf(const char *devname) { struct dirent *de, *d_de; DIR *dir, *d_dir; char path[300]; int ret = 1; if ((dir = opendir("/sys/block")) == NULL) return 0; while ((de = readdir(dir)) != NULL) { if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, "..") || !strcmp(de->d_name, devname) || strncmp(de->d_name, "dm-", 3) || strlen(de->d_name) > sizeof(path)-32) continue; sprintf(path, "/sys/block/%s/slaves", de->d_name); if ((d_dir = opendir(path)) == NULL) continue; while ((d_de = readdir(d_dir)) != NULL) { if (!strcmp(d_de->d_name, devname)) { ret = 0; break; } } closedir(d_dir); if (!ret) break; } closedir(dir); return ret; } /* * Since 2.6.29 (patch 784aae735d9b0bba3f8b9faef4c8b30df3bf0128) kernel sysfs * provides the real DM device names in /sys/block/<ptname>/dm/name */ static char *get_dm_name(const char *ptname) { FILE *f; size_t sz; char path[300], name[256], *res = NULL; snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptname); if ((f = fopen(path, "r")) == NULL) return NULL; /* read "<name>\n" from sysfs */ if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) { name[sz - 1] = '\0'; snprintf(path, sizeof(path), "/dev/mapper/%s", name); res = blkid_strdup(path); } fclose(f); return res; } /* * 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) { 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 = 0; } } if (dev && dev->bid_devno == devno) goto set_pri; /* Try to translate private device-mapper dm-<N> names * to standard /dev/mapper/<name>. */ if (!strncmp(ptname, "dm-", 3) && isdigit(ptname[3])) { devname = get_dm_name(ptname); if (!devname) blkid__scan_dir("/dev/mapper", devno, 0, &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]; sprintf(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 && blkidP_is_disk_device(st.st_mode) && st.st_rdev == devno) { devname = blkid_strdup(device); goto get_dev; } } /* Do a short-cut scan of /dev/mapper first */ if (!devname) devname = get_dm_name(ptname); if (!devname) blkid__scan_dir("/dev/mapper", devno, 0, &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/", 11)) { 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; } return; } #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(DEBUG_DEVNAME, printf("opening %s\n", lvm_device)); if ((lvf = fopen(lvm_device, "r")) == NULL) { DBG(DEBUG_DEVNAME, printf("%s: (%d) %s\n", lvm_device, errno, strerror(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(DEBUG_DEVNAME, printf("probing LVM devices under %s\n", VG_DIR)); while ((vg_iter = readdir(vg_list)) != NULL) { DIR *lv_list; char *vdirname; char *vg_name; struct dirent *lv_iter; vg_name = vg_iter->d_name; if (!strcmp(vg_name, ".") || !strcmp(vg_name, "..")) continue; vdirname = malloc(vg_len + strlen(vg_name) + 8); if (!vdirname) goto exit; sprintf(vdirname, "%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; lvm_device = malloc(vg_len + strlen(vg_name) + strlen(lv_name) + 8); if (!lvm_device) { closedir(lv_list); goto exit; } sprintf(lvm_device, "%s/%s/LVs/%s", VG_DIR, vg_name, lv_name); dev = lvm_get_devno(lvm_device); sprintf(lvm_device, "%s/%s", vg_name, lv_name); DBG(DEBUG_DEVNAME, printf("LVM dev %s: devno 0x%04X\n", lvm_device, (unsigned int) dev)); probe_one(cache, lvm_device, dev, BLKID_PRI_LVM, only_if_new); free(lvm_device); } closedir(lv_list); } exit: closedir(vg_list); } #endif #define PROC_EVMS_VOLUMES "/proc/evms/volumes" static int evms_probe_all(blkid_cache cache, int only_if_new) { char line[100]; int ma, mi, sz, num = 0; FILE *procpt; char device[110]; procpt = fopen(PROC_EVMS_VOLUMES, "r"); if (!procpt) return 0; while (fgets(line, sizeof(line), procpt)) { if (sscanf (line, " %d %d %d %*s %*s %[^\n ]", &ma, &mi, &sz, device) != 4) continue; DBG(DEBUG_DEVNAME, printf("Checking partition %s (%d, %d)\n", device, ma, mi)); probe_one(cache, device, makedev(ma, mi), BLKID_PRI_EVMS, only_if_new); num++; } fclose(procpt); return num; } /* * Read the device data for all available block devices in the system. */ static int probe_all(blkid_cache cache, int only_if_new) { FILE *proc; char line[1024]; char ptname0[129], ptname1[129], *ptname = 0; char *ptnames[2]; dev_t devs[2]; int ma, mi; unsigned long long sz; int lens[2] = { 0, 0 }; int which = 0, last = 0; struct list_head *p, *pnext; ptnames[0] = ptname0; ptnames[1] = ptname1; if (!cache) return -BLKID_ERR_PARAM; if (cache->bic_flags & BLKID_BIC_FL_PROBED && time(0) - cache->bic_time < BLKID_PROBE_INTERVAL) return 0; blkid_read_cache(cache); evms_probe_all(cache, only_if_new); #ifdef VG_DIR lvm_probe_all(cache, only_if_new); #endif proc = fopen(PROC_PARTITIONS, "r"); if (!proc) return -BLKID_ERR_PROC; while (fgets(line, sizeof(line), proc)) { last = which; which ^= 1; ptname = ptnames[which]; if (sscanf(line, " %d %d %llu %128[^\n ]", &ma, &mi, &sz, ptname) != 4) continue; devs[which] = makedev(ma, mi); DBG(DEBUG_DEVNAME, printf("read partition name %s\n", ptname)); /* Skip whole disk devs unless they have no partitions. * If base name of device has changed, also * check previous dev to see if it didn't have a partn. * heuristic: partition name ends in a digit, & partition * names contain whole device name as substring. * * Skip extended partitions. * heuristic: size is 1 * * FIXME: skip /dev/{ida,cciss,rd} whole-disk devs */ lens[which] = strlen(ptname); /* ends in a digit, clearly a partition, so check */ if (isdigit(ptname[lens[which] - 1])) { DBG(DEBUG_DEVNAME, printf("partition dev %s, devno 0x%04X\n", ptname, (unsigned int) devs[which])); if (sz > 1) probe_one(cache, ptname, devs[which], 0, only_if_new); lens[which] = 0; /* mark as checked */ } /* * If last was a whole disk and we just found a partition * on it, remove the whole-disk dev from the cache if * it exists. */ if (lens[last] && !strncmp(ptnames[last], ptname, lens[last])) { list_for_each_safe(p, pnext, &cache->bic_devs) { blkid_dev tmp; /* find blkid dev for the whole-disk devno */ tmp = list_entry(p, struct blkid_struct_dev, bid_devs); if (tmp->bid_devno == devs[last]) { DBG(DEBUG_DEVNAME, printf("freeing %s\n", tmp->bid_name)); blkid_free_dev(tmp); cache->bic_flags |= BLKID_BIC_FL_CHANGED; break; } } lens[last] = 0; } /* * If last was not checked because it looked like a whole-disk * dev, and the device's base name has changed, * check last as well. */ if (lens[last] && strncmp(ptnames[last], ptname, lens[last])) { DBG(DEBUG_DEVNAME, printf("whole dev %s, devno 0x%04X\n", ptnames[last], (unsigned int) devs[last])); probe_one(cache, ptnames[last], devs[last], 0, only_if_new); lens[last] = 0; } } /* Handle the last device if it wasn't partitioned */ if (lens[which]) probe_one(cache, ptname, devs[which], 0, only_if_new); fclose(proc); blkid_flush_cache(cache); return 0; } int blkid_probe_all(blkid_cache cache) { int ret; DBG(DEBUG_PROBE, printf("Begin blkid_probe_all()\n")); ret = probe_all(cache, 0); cache->bic_time = time(0); cache->bic_flags |= BLKID_BIC_FL_PROBED; DBG(DEBUG_PROBE, printf("End blkid_probe_all()\n")); return ret; } int blkid_probe_all_new(blkid_cache cache) { int ret; DBG(DEBUG_PROBE, printf("Begin blkid_probe_all_new()\n")); ret = probe_all(cache, 1); DBG(DEBUG_PROBE, printf("End blkid_probe_all_new()\n")); return ret; } #ifdef TEST_PROGRAM int main(int argc, char **argv) { blkid_cache cache = NULL; int ret; blkid_debug_mask = 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]); blkid_put_cache(cache); return (0); } #endif