Use provider's ident to handle situations when disks are moved around

and show up with different names: first try to open provider using
remembered name and compare its ident, if equal, this is our provider,
if not equal or there is no provider with such name, find provider with
remembered ident and don't care about the name.

1 files changed, 161 insertions, 10 deletions

diff --git a/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c b/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
index 39358e9..859895a 100644
--- a/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
+++ b/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
@@ -27,11 +27,13 @@
 #include <sys/param.h>
 #include <sys/kernel.h>
 #include <sys/bio.h>
+#include <sys/disk.h>
 #include <sys/spa.h>
 #include <sys/vdev_impl.h>
 #include <sys/fs/zfs.h>
 #include <sys/zio.h>
 #include <geom/geom.h>
+#include <geom/geom_int.h>
 
 /*
  * Virtual device vector for GEOM.
@@ -83,7 +85,8 @@ vdev_geom_orphan(struct g_consumer *cp)
 	error = cp->provider->error;
 
 	ZFS_LOG(1, "Closing access to %s.", cp->provider->name);
-	g_access(cp, -cp->acr, -cp->acw, -cp->ace);
+	if (cp->acr + cp->acw + cp->ace > 0)
+		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
 	ZFS_LOG(1, "Destroyed consumer to %s.", cp->provider->name);
 	g_detach(cp);
 	g_destroy_consumer(cp);
@@ -113,8 +116,11 @@ vdev_geom_attach(struct g_provider *pp, int write)
 	ZFS_LOG(1, "Attaching to %s.", pp->name);
 	/* Do we have geom already? No? Create one. */
 	LIST_FOREACH(gp, &zfs_vdev_class.geom, geom) {
-		if (!(gp->flags & G_GEOM_WITHER))
-			break;
+		if (gp->flags & G_GEOM_WITHER)
+			continue;
+		if (strcmp(gp->name, "zfs::vdev") != 0)
+			continue;
+		break;
 	}
 	if (gp == NULL) {
 		gp = g_new_geomf(&zfs_vdev_class, "zfs::vdev");
@@ -227,12 +233,125 @@ vdev_geom_worker(void *arg)
 	}
 }
 
+static char *
+vdev_geom_get_id(struct g_consumer *cp)
+{
+	char *id;
+	int len;
+
+	g_topology_assert_not();
+	len = DISK_IDENT_SIZE;
+	id = kmem_zalloc(len, KM_SLEEP);
+	if (g_io_getattr("GEOM::ident", cp, &len, id) != 0) {
+		kmem_free(id, DISK_IDENT_SIZE);
+		return (NULL);
+	}
+	return (id);
+}
+
+static void
+vdev_geom_free_id(char *id)
+{
+
+	if (id != NULL)
+		kmem_free(id, DISK_IDENT_SIZE);
+}
+
+struct vdev_geom_find {
+	const char *id;
+	int write;
+	struct g_consumer *cp;
+};
+
+static void
+vdev_geom_taste_orphan(struct g_consumer *cp)
+{
+
+	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
+	    cp->provider->name));
+}
+
+static void
+vdev_geom_attach_by_id_event(void *arg, int flags __unused)
+{
+	struct vdev_geom_find *ap;
+	struct g_class *mp;
+	struct g_geom *gp, *zgp;
+	struct g_provider *pp;
+	struct g_consumer *zcp;
+	char *id;
+
+	g_topology_assert();
+
+	ap = arg;
+
+	zgp = g_new_geomf(&zfs_vdev_class, "zfs::vdev::taste");
+	/* This orphan function should be never called. */
+	zgp->orphan = vdev_geom_taste_orphan;
+	zcp = g_new_consumer(zgp);
+
+	LIST_FOREACH(mp, &g_classes, class) {
+		if (mp == &zfs_vdev_class)
+			continue;
+		LIST_FOREACH(gp, &mp->geom, geom) {
+			if (gp->flags & G_GEOM_WITHER)
+				continue;
+			LIST_FOREACH(pp, &gp->provider, provider) {
+				if (pp->flags & G_PF_WITHER)
+					continue;
+				g_attach(zcp, pp);
+				if (g_access(zcp, 1, 0, 0) != 0) {
+					g_detach(zcp);
+					continue;
+				}
+				g_topology_unlock();
+				id = vdev_geom_get_id(zcp);
+				g_topology_lock();
+				g_access(zcp, -1, 0, 0);
+				g_detach(zcp);
+				if (id == NULL || strcmp(id, ap->id) != 0) {
+					vdev_geom_free_id(id);
+					continue;
+				}
+				vdev_geom_free_id(id);
+				ap->cp = vdev_geom_attach(pp, ap->write);
+				if (ap->cp == NULL) {
+					printf("ZFS WARNING: Cannot open %s "
+					    "for writting.\n", pp->name);
+					continue;
+				}
+				goto end;
+			}
+		}
+	}
+	ap->cp = NULL;
+end:
+	g_destroy_consumer(zcp);
+	g_destroy_geom(zgp);
+}
+
+static struct g_consumer *
+vdev_geom_attach_by_id(const char *id, int write)
+{
+	struct vdev_geom_find *ap;
+	struct g_consumer *cp;
+
+	ap = kmem_zalloc(sizeof(*ap), KM_SLEEP);
+	ap->id = id;
+	ap->write = write;
+	g_waitfor_event(vdev_geom_attach_by_id_event, ap, M_WAITOK, NULL);
+	cp = ap->cp;
+	kmem_free(ap, sizeof(*ap));
+	return (cp);
+}
+
 static int
 vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 {
 	vdev_geom_ctx_t *ctx;
 	struct g_provider *pp;
 	struct g_consumer *cp;
+	char *id = NULL;
 	int owned;
 
 	/*
@@ -245,23 +364,55 @@ vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
 
 	if ((owned = mtx_owned(&Giant)))
 		mtx_unlock(&Giant);
+	cp = NULL;
 	g_topology_lock();
 	pp = g_provider_by_name(vd->vdev_path + sizeof("/dev/") - 1);
-	if (pp == NULL) {
-		g_topology_unlock();
-		if (owned)
-			mtx_lock(&Giant);
-		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
-		return (EINVAL);
+	if (pp != NULL) {
+		ZFS_LOG(1, "Found provider by name %s.", vd->vdev_path);
+		cp = vdev_geom_attach(pp, !!(spa_mode & FWRITE));
+		if (cp != NULL && vd->vdev_devid != NULL) {
+			g_topology_unlock();
+			id = vdev_geom_get_id(cp);
+			g_topology_lock();
+			if (id == NULL || strcmp(id, vd->vdev_devid) != 0) {
+				vdev_geom_detach(cp, 0);
+				cp = NULL;
+				ZFS_LOG(1, "ID mismatch for provider %s: "
+				    "[%s]!=[%s].", vd->vdev_path,
+				    vd->vdev_devid, id);
+				goto next;
+			}
+			ZFS_LOG(1, "ID match for provider %s.", vd->vdev_path);
+		}
 	}
-	cp = vdev_geom_attach(pp, !!(spa_mode & FWRITE));
+next:
 	g_topology_unlock();
+	vdev_geom_free_id(id);
+	if (cp == NULL && vd->vdev_devid != NULL) {
+		ZFS_LOG(0, "Searching by ID [%s].", vd->vdev_devid);
+		cp = vdev_geom_attach_by_id(vd->vdev_devid,
+		    !!(spa_mode & FWRITE));
+		if (cp != NULL) {
+			size_t len = strlen(cp->provider->name) + 6; /* 6 == strlen("/dev/") + 1 */
+			char *buf = kmem_alloc(len, KM_SLEEP);
+
+			snprintf(buf, len, "/dev/%s", cp->provider->name);
+			spa_strfree(vd->vdev_path);
+			vd->vdev_path = buf;
+
+			ZFS_LOG(1, "Attach by ID [%s] succeeded, provider %s.",
+			    vd->vdev_devid, vd->vdev_path);
+		}
+	}
 	if (owned)
 		mtx_lock(&Giant);
 	if (cp == NULL) {
+		ZFS_LOG(1, "Provider %s (id=[%s]) not found.", vd->vdev_path,
+		    vd->vdev_devid);
 		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 		return (EACCES);
 	}
+	pp = cp->provider;
 
 	/*
 	 * Determine the actual size of the device.