loopdev: report lost loop devices

[thirdparty/util-linux.git] / lib / loopdev.c

diff --git a/lib/loopdev.c b/lib/loopdev.c
index dae499f256fa07c8b00a9913cd45c9ad81f733b4..c72fb2c404b676ed7cfd0234ebb4b4ad256d2625 100644 (file)
--- a/lib/loopdev.c
+++ b/lib/loopdev.c
@@ -116,6 +116,8 @@ int loopcxt_set_device(struct loopdev_cxt *lc, const char *device)
                DBG(CXT, ul_debugobj(lc, "closing old open fd"));
        }
        lc->fd = -1;
+       lc->is_lost = 0;
+       lc->devno = 0;
        lc->mode = O_RDONLY;
        lc->blocksize = 0;
        lc->has_info = 0;
@@ -153,6 +155,28 @@ int loopcxt_has_device(struct loopdev_cxt *lc)
        return lc && *lc->device;
 }
 
+dev_t loopcxt_get_devno(struct loopdev_cxt *lc)
+{
+       if (!lc || !loopcxt_has_device(lc))
+               return 0;
+       if (!lc->devno)
+               lc->devno = sysfs_devname_to_devno(lc->device);
+       return lc->devno;
+}
+
+int loopcxt_is_lost(struct loopdev_cxt *lc)
+{
+       if (!lc || !loopcxt_has_device(lc))
+               return 0;
+       if (lc->is_lost)
+               return 1;
+
+       lc->is_lost = access(lc->device, F_OK) != 0
+                       && loopcxt_get_devno(lc) != 0;
+
+       return lc->is_lost;
+}
+
 /*
  * @lc: context
  * @flags: LOOPDEV_FL_* flags
@@ -265,7 +289,7 @@ static struct path_cxt *loopcxt_get_sysfs(struct loopdev_cxt *lc)
                return NULL;
 
        if (!lc->sysfs) {
-               dev_t devno = sysfs_devname_to_devno(lc->device);
+               dev_t devno = loopcxt_get_devno(lc);
                if (!devno) {
                        DBG(CXT, ul_debugobj(lc, "sysfs: failed devname to devno"));
                        return NULL;
@@ -416,13 +440,6 @@ static int loopiter_set_device(struct loopdev_cxt *lc, const char *device)
            !(lc->iter.flags & LOOPITER_FL_FREE))
                return 0;       /* caller does not care about device status */
 
-       if (!is_loopdev(lc->device)) {
-               DBG(ITER, ul_debugobj(&lc->iter, "%s does not exist", lc->device));
-               return -errno;
-       }
-
-       DBG(ITER, ul_debugobj(&lc->iter, "%s exist", lc->device));
-
        used = loopcxt_get_offset(lc, NULL) == 0;
 
        if ((lc->iter.flags & LOOPITER_FL_USED) && used)
@@ -876,7 +893,7 @@ int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size)
 
 /*
  * @lc: context
- * @devno: returns encryption type
+ * @type: returns encryption type
  *
  * Cryptoloop is DEPRECATED!
  *
@@ -901,7 +918,6 @@ int loopcxt_get_encrypt_type(struct loopdev_cxt *lc, uint32_t *type)
 
 /*
  * @lc: context
- * @devno: returns crypt name
  *
  * Cryptoloop is DEPRECATED!
  *