Illumos #3090 and #3102

[zfs.git] / module / zfs / vdev_label.c

diff --git a/module/zfs/vdev_label.c b/module/zfs/vdev_label.c
index 352b630..1fe36fe 100644 (file)
--- a/module/zfs/vdev_label.c
+++ b/module/zfs/vdev_label.c
@@ -433,17 +433,22 @@ vdev_top_config_generate(spa_t *spa, nvlist_t *config)
 }
 
 /*
- * Returns the configuration from the label of the given vdev. If 'label' is
- * VDEV_BEST_LABEL, each label of the vdev will be read until a valid
- * configuration is found; otherwise, only the specified label will be read.
+ * Returns the configuration from the label of the given vdev. For vdevs
+ * which don't have a txg value stored on their label (i.e. spares/cache)
+ * or have not been completely initialized (txg = 0) just return
+ * the configuration from the first valid label we find. Otherwise,
+ * find the most up-to-date label that does not exceed the specified
+ * 'txg' value.
  */
 nvlist_t *
-vdev_label_read_config(vdev_t *vd, int label)
+vdev_label_read_config(vdev_t *vd, uint64_t txg)
 {
        spa_t *spa = vd->vdev_spa;
        nvlist_t *config = NULL;
        vdev_phys_t *vp;
        zio_t *zio;
+       uint64_t best_txg = 0;
+       int error = 0;
        int flags = ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_CANFAIL |
            ZIO_FLAG_SPECULATIVE;
        int l;
@@ -457,8 +462,7 @@ vdev_label_read_config(vdev_t *vd, int label)
 
 retry:
        for (l = 0; l < VDEV_LABELS; l++) {
-               if (label >= 0 && label < VDEV_LABELS && label != l)
-                       continue;
+               nvlist_t *label = NULL;
 
                zio = zio_root(spa, NULL, NULL, flags);
 
@@ -468,12 +472,31 @@ retry:
 
                if (zio_wait(zio) == 0 &&
                    nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist),
-                   &config, 0) == 0)
-                       break;
+                   &label, 0) == 0) {
+                       uint64_t label_txg = 0;
+
+                       /*
+                        * Auxiliary vdevs won't have txg values in their
+                        * labels and newly added vdevs may not have been
+                        * completely initialized so just return the
+                        * configuration from the first valid label we
+                        * encounter.
+                        */
+                       error = nvlist_lookup_uint64(label,
+                           ZPOOL_CONFIG_POOL_TXG, &label_txg);
+                       if ((error || label_txg == 0) && !config) {
+                               config = label;
+                               break;
+                       } else if (label_txg <= txg && label_txg > best_txg) {
+                               best_txg = label_txg;
+                               nvlist_free(config);
+                               config = fnvlist_dup(label);
+                       }
+               }
 
-               if (config != NULL) {
-                       nvlist_free(config);
-                       config = NULL;
+               if (label != NULL) {
+                       nvlist_free(label);
+                       label = NULL;
                }
        }
 
@@ -508,7 +531,7 @@ vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason,
        /*
         * Read the label, if any, and perform some basic sanity checks.
         */
-       if ((label = vdev_label_read_config(vd, VDEV_BEST_LABEL)) == NULL)
+       if ((label = vdev_label_read_config(vd, -1ULL)) == NULL)
                return (B_FALSE);
 
        (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG,
@@ -872,7 +895,6 @@ vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2)
 struct ubl_cbdata {
        uberblock_t     *ubl_ubbest;    /* Best uberblock */
        vdev_t          *ubl_vd;        /* vdev associated with the above */
-       int             ubl_label;      /* Label associated with the above */
 };
 
 static void
@@ -891,15 +913,13 @@ vdev_uberblock_load_done(zio_t *zio)
                if (ub->ub_txg <= spa->spa_load_max_txg &&
                    vdev_uberblock_compare(ub, cbp->ubl_ubbest) > 0) {
                        /*
-                        * Keep track of the vdev and label in which this
-                        * uberblock was found. We will use this information
-                        * later to obtain the config nvlist associated with
+                        * Keep track of the vdev in which this uberblock
+                        * was found. We will use this information later
+                        * to obtain the config nvlist associated with
                         * this uberblock.
                         */
                        *cbp->ubl_ubbest = *ub;
                        cbp->ubl_vd = vd;
-                       cbp->ubl_label = vdev_label_number(vd->vdev_psize,
-                           zio->io_offset);
                }
                mutex_exit(&rio->io_lock);
        }
@@ -933,12 +953,11 @@ vdev_uberblock_load_impl(zio_t *zio, vdev_t *vd, int flags,
  * Reads the 'best' uberblock from disk along with its associated
  * configuration. First, we read the uberblock array of each label of each
  * vdev, keeping track of the uberblock with the highest txg in each array.
- * Then, we read the configuration from the same label as the best uberblock.
+ * Then, we read the configuration from the same vdev as the best uberblock.
  */
 void
 vdev_uberblock_load(vdev_t *rvd, uberblock_t *ub, nvlist_t **config)
 {
-       int i;
        zio_t *zio;
        spa_t *spa = rvd->vdev_spa;
        struct ubl_cbdata cb;
@@ -958,13 +977,15 @@ vdev_uberblock_load(vdev_t *rvd, uberblock_t *ub, nvlist_t **config)
        zio = zio_root(spa, NULL, &cb, flags);
        vdev_uberblock_load_impl(zio, rvd, flags, &cb);
        (void) zio_wait(zio);
-       if (cb.ubl_vd != NULL) {
-               for (i = cb.ubl_label % 2; i < VDEV_LABELS; i += 2) {
-                       *config = vdev_label_read_config(cb.ubl_vd, i);
-                       if (*config != NULL)
-                               break;
-               }
-       }
+
+       /*
+        * It's possible that the best uberblock was discovered on a label
+        * that has a configuration which was written in a future txg.
+        * Search all labels on this vdev to find the configuration that
+        * matches the txg for our uberblock.
+        */
+       if (cb.ubl_vd != NULL)
+               *config = vdev_label_read_config(cb.ubl_vd, ub->ub_txg);
        spa_config_exit(spa, SCL_ALL, FTAG);
 }