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libext2fs: fix ext2fs_close() when MMP is not enabled
[tools/e2fsprogs.git] / lib / blkid / devname.c
index df77001..3e2efa9 100644 (file)
  * %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
@@ -22,6 +26,7 @@
 #if HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
+#include <dirent.h>
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
@@ -44,7 +49,7 @@
 blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
 {
        blkid_dev dev = NULL, tmp;
-       struct list_head *p;
+       struct list_head *p, *pnext;
 
        if (!cache || !devname)
                return NULL;
@@ -54,57 +59,167 @@ blkid_dev blkid_get_dev(blkid_cache cache, const char *devname, int flags)
                if (strcmp(tmp->bid_name, devname))
                        continue;
 
-               DBG(DEBUG_DEVNAME, 
+               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_devname(cache, dev);
+       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[256];
+       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[256], 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)
+                     dev_t devno, int pri, int only_if_new)
 {
        blkid_dev dev = NULL;
-       struct list_head *p;
+       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(p, &cache->bic_devs) {
+       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) {
-                       dev = blkid_verify_devname(cache, tmp);
-                       break;
+                       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 = blkid_devdirs; *dir; dir++) {
+       for (dir = dirlist; *dir; dir++) {
                struct stat st;
                char device[256];
 
@@ -113,23 +228,36 @@ static void probe_one(blkid_cache cache, const char *ptname,
                    dev->bid_devno == devno)
                        goto set_pri;
 
-               if (stat(device, &st) == 0 && st.st_rdev == devno) {
+               if (stat(device, &st) == 0 && S_ISBLK(st.st_mode) &&
+                   st.st_rdev == devno) {
                        devname = blkid_strdup(device);
-                       break;
+                       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 (!pri && !strncmp(ptname, "md", 2))
-               pri = BLKID_PRI_MD;
-       dev->bid_pri = 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;
 }
 
@@ -143,7 +271,6 @@ set_pri:
  * safe thing to do?)
  */
 #ifdef VG_DIR
-#include <dirent.h>
 static dev_t lvm_get_devno(const char *lvm_device)
 {
        FILE *lvf;
@@ -169,7 +296,7 @@ static dev_t lvm_get_devno(const char *lvm_device)
        return ret;
 }
 
-static void lvm_probe_all(blkid_cache cache)
+static void lvm_probe_all(blkid_cache cache, int only_if_new)
 {
        DIR             *vg_list;
        struct dirent   *vg_iter;
@@ -220,7 +347,8 @@ static void lvm_probe_all(blkid_cache cache)
                        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);
+                       probe_one(cache, lvm_device, dev, BLKID_PRI_LVM,
+                                 only_if_new);
                        free(lvm_device);
                }
                closedir(lv_list);
@@ -233,7 +361,7 @@ exit:
 #define PROC_EVMS_VOLUMES "/proc/evms/volumes"
 
 static int
-evms_probe_all(blkid_cache cache)
+evms_probe_all(blkid_cache cache, int only_if_new)
 {
        char line[100];
        int ma, mi, sz, num = 0;
@@ -251,7 +379,8 @@ evms_probe_all(blkid_cache cache)
                DBG(DEBUG_DEVNAME, printf("Checking partition %s (%d, %d)\n",
                                          device, ma, mi));
 
-               probe_one(cache, device, makedev(ma, mi), BLKID_PRI_EVMS);
+               probe_one(cache, device, makedev(ma, mi), BLKID_PRI_EVMS,
+                         only_if_new);
                num++;
        }
        fclose(procpt);
@@ -261,7 +390,7 @@ evms_probe_all(blkid_cache cache)
 /*
  * Read the device data for all available block devices in the system.
  */
-int blkid_probe_all(blkid_cache cache)
+static int probe_all(blkid_cache cache, int only_if_new)
 {
        FILE *proc;
        char line[1024];
@@ -272,6 +401,7 @@ int blkid_probe_all(blkid_cache cache)
        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;
@@ -284,9 +414,9 @@ int blkid_probe_all(blkid_cache cache)
                return 0;
 
        blkid_read_cache(cache);
-       evms_probe_all(cache);
+       evms_probe_all(cache, only_if_new);
 #ifdef VG_DIR
-       lvm_probe_all(cache);
+       lvm_probe_all(cache, only_if_new);
 #endif
 
        proc = fopen(PROC_PARTITIONS, "r");
@@ -298,17 +428,18 @@ int blkid_probe_all(blkid_cache cache)
                which ^= 1;
                ptname = ptnames[which];
 
-               if (sscanf(line, " %d %d %lld %128[^\n ]",
+               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
+               /* 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.
+                * heuristic: partition name ends in a digit, & partition
+                * names contain whole device name as substring.
                 *
                 * Skip extended partitions.
                 * heuristic: size is 1
@@ -317,37 +448,89 @@ int blkid_probe_all(blkid_cache cache)
                 */
 
                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);
-                       lens[which] = 0;
+                               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;
-               } else if (lens[last] && strncmp(ptnames[last], ptname,
-                                                lens[last])) {
+               }
+               /*
+                * 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);
+                       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);
+               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;
-       blkid_flush_cache(cache);
-       return 0;
+       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)
 {