/* vi: set sw=4 ts=4: */ /* * 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% */ #include #include #ifdef HAVE_UNISTD_H #include #endif #include #include #include #ifdef HAVE_SYS_TYPES_H #include #endif #include #ifdef HAVE_ERRNO_H #include #endif #ifdef HAVE_SYS_MKDEV_H #include #endif #include #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; 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)) { dev = blkid_new_dev(); if (!dev) return NULL; 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); return dev; } /* * 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) { blkid_dev dev = NULL; struct list_head *p; const char **dir; char *devname = NULL; /* See if we already have this device number in the cache. */ list_for_each(p, &cache->bic_devs) { blkid_dev tmp = list_entry(p, struct blkid_struct_dev, bid_devs); if (tmp->bid_devno == devno) { dev = blkid_verify(cache, tmp); break; } } if (dev && dev->bid_devno == devno) goto set_pri; /* * 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 = blkid_devdirs; *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 && S_ISBLK(st.st_mode) && st.st_rdev == devno) { devname = blkid_strdup(device); break; } } if (!devname) { devname = blkid_devno_to_devname(devno); if (!devname) return; } dev = blkid_get_dev(cache, devname, BLKID_DEV_NORMAL); free(devname); set_pri: if (!pri && !strncmp(ptname, "md", 2)) pri = BLKID_PRI_MD; if (dev) dev->bid_pri = pri; } #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 #include 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_for_read(lvm_device)) == 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) { 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 (LONE_CHAR(vg_name, '.') || !strcmp(vg_name, "..")) continue; vdirname = xmalloc(vg_len + strlen(vg_name) + 8); 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 (LONE_CHAR(lv_name, '.') || !strcmp(lv_name, "..")) continue; lvm_device = xmalloc(vg_len + strlen(vg_name) + strlen(lv_name) + 8); 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); free(lvm_device); } closedir(lv_list); } closedir(vg_list); } #endif #define PROC_EVMS_VOLUMES "/proc/evms/volumes" static int evms_probe_all(blkid_cache cache) { char line[100]; int ma, mi, sz, num = 0; FILE *procpt; char device[110]; procpt = fopen_for_read(PROC_EVMS_VOLUMES); 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); num++; } fclose(procpt); return num; } /* * Read the device data for all available block devices in the system. */ int blkid_probe_all(blkid_cache cache) { FILE *proc; char line[1024]; char ptname0[128], ptname1[128], *ptname = NULL; char *ptnames[2]; dev_t devs[2]; int ma, mi; unsigned long long sz; int lens[2] = { 0, 0 }; int which = 0, last = 0; ptnames[0] = ptname0; ptnames[1] = ptname1; if (!cache) return -BLKID_ERR_PARAM; if (cache->bic_flags & BLKID_BIC_FL_PROBED && time(NULL) - cache->bic_time < BLKID_PROBE_INTERVAL) return 0; blkid_read_cache(cache); evms_probe_all(cache); #ifdef VG_DIR lvm_probe_all(cache); #endif proc = fopen_for_read(PROC_PARTITIONS); 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 we don't have a partition on this dev, also * check previous dev to see if it didn't have a partn. * heuristic: partition name ends in a digit. * * Skip extended partitions. * heuristic: size is 1 * * FIXME: skip /dev/{ida,cciss,rd} whole-disk devs */ lens[which] = strlen(ptname); 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); lens[which] = 0; lens[last] = 0; } else 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); lens[last] = 0; } } /* Handle the last device if it wasn't partitioned */ if (lens[which]) probe_one(cache, ptname, devs[which], 0); fclose(proc); cache->bic_time = time(NULL); cache->bic_flags |= BLKID_BIC_FL_PROBED; blkid_flush_cache(cache); return 0; } #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, bb_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