Attachment 147915 Details for Bug 193803 – Possible fix for zvol hang issues (against 10.0-RELEASE)

[patch] Possible fix for zvol hang issues (against 10.0-RELEASE)

zfs-zvol-fixes.patch (text/plain), 7.05 KB, created by Steven Hartland on 2014-10-02 15:27:54 UTC

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Creator: Steven Hartland

Created: 2014-10-02 15:27:54 UTC

Size: 7.05 KB

patch

obsolete

>Various fixes for zvol devices not being correctly maintained when operations
>which effect them occur.
>--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c.orig	2014-03-26 17:52:33.000000000 +0000
>+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_dataset.c	2014-09-29 18:52:24.903520480 +0000
>@@ -1655,11 +1655,9 @@ static int
> dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
>     dsl_dataset_t *hds, void *arg)
> {
>-#ifdef __FreeBSD__
>-#ifdef _KERNEL
>+#if defined(__FreeBSD__) && defined(_KERNEL)
> 	char *oldname, *newname;
> #endif
>-#endif
> 	dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
> 	dsl_dataset_t *ds;
> 	uint64_t val;
>@@ -1686,8 +1684,7 @@ dsl_dataset_rename_snapshot_sync_impl(ds
> 	VERIFY0(zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj,
> 	    ds->ds_snapname, 8, 1, &ds->ds_object, tx));
> 
>-#ifdef __FreeBSD__
>-#ifdef _KERNEL
>+#if defined(__FreeBSD__) && defined (_KERNEL)
> 	oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
> 	newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
> 	snprintf(oldname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
>@@ -1699,7 +1696,6 @@ dsl_dataset_rename_snapshot_sync_impl(ds
> 	kmem_free(newname, MAXPATHLEN);
> 	kmem_free(oldname, MAXPATHLEN);
> #endif
>-#endif
> 	dsl_dataset_rele(ds, FTAG);
> 
> 	return (0);
>@@ -2076,6 +2072,9 @@ dsl_dataset_promote_sync(void *arg, dmu_
> 	dsl_dir_t *odd = NULL;
> 	uint64_t oldnext_obj;
> 	int64_t delta;
>+#if defined(__FreeBSD__) && defined(_KERNEL)
>+	char *oldname, *newname;
>+#endif
> 
> 	VERIFY0(promote_hold(ddpa, dp, FTAG));
> 	hds = ddpa->ddpa_clone;
>@@ -2141,6 +2140,14 @@ dsl_dataset_promote_sync(void *arg, dmu_
> 		    dd->dd_phys->dd_clones, origin_head->ds_object, tx));
> 	}
> 
>+#if defined(__FreeBSD__) && defined(_KERNEL)
>+	/* Take the spa_namespace_lock so zvol renames don't livelock */
>+	mutex_enter(&spa_namespace_lock);
>+
>+	oldname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
>+	newname = kmem_alloc(MAXPATHLEN, KM_SLEEP);
>+#endif
>+
> 	/* move snapshots to this dir */
> 	for (snap = list_head(&ddpa->shared_snaps); snap;
> 	    snap = list_next(&ddpa->shared_snaps, snap)) {
>@@ -2173,6 +2180,12 @@ dsl_dataset_promote_sync(void *arg, dmu_
> 		VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
> 		    NULL, ds, &ds->ds_dir));
> 
>+#if defined(__FreeBSD__) && defined(_KERNEL)
>+		dsl_dataset_name(ds, newname);
>+		zfsvfs_update_fromname(oldname, newname);
>+		zvol_rename_minors(oldname, newname);
>+#endif
>+
> 		/* move any clone references */
> 		if (ds->ds_phys->ds_next_clones_obj &&
> 		    spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
>@@ -2210,6 +2223,12 @@ dsl_dataset_promote_sync(void *arg, dmu_
> 		ASSERT(!dsl_prop_hascb(ds));
> 	}
> 
>+#if defined(__FreeBSD__) && defined(_KERNEL)
>+	mutex_exit(&spa_namespace_lock);
>+
>+	kmem_free(newname, MAXPATHLEN);
>+	kmem_free(oldname, MAXPATHLEN);
>+#endif
> 	/*
> 	 * Change space accounting.
> 	 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
>--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zvol.h.orig	2014-03-26 17:52:33.000000000 +0000
>+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zvol.h	2014-09-29 18:52:24.903520480 +0000
>@@ -41,8 +41,7 @@ extern int zvol_check_volblocksize(uint6
> extern int zvol_get_stats(objset_t *os, nvlist_t *nv);
> extern void zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx);
> extern int zvol_create_minor(const char *);
>-extern int zvol_remove_minor(const char *);
>-extern void zvol_remove_minors(const char *);
>+extern int zvol_remove_minors(const char *);
> extern int zvol_set_volsize(const char *, major_t, uint64_t);
> 
> #ifdef sun
>--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c.orig	2014-03-26 17:52:33.000000000 +0000
>+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ioctl.c	2014-09-29 18:52:24.908521871 +0000
>@@ -3517,7 +3517,7 @@ zfs_ioc_destroy_snaps(const char *poolna
> 		error = zfs_unmount_snap(name);
> 		if (error != 0)
> 			return (error);
>-		(void) zvol_remove_minor(name);
>+		(void) zvol_remove_minors(name);
> 	}
> 
> 	return (dsl_destroy_snapshots_nvl(snaps, defer, outnvl));
>@@ -3547,7 +3547,7 @@ zfs_ioc_destroy(zfs_cmd_t *zc)
> 	else
> 		err = dsl_destroy_head(zc->zc_name);
> 	if (zc->zc_objset_type == DMU_OST_ZVOL && err == 0)
>-		(void) zvol_remove_minor(zc->zc_name);
>+		(void) zvol_remove_minors(zc->zc_name);
> 	return (err);
> }
> 
>@@ -3643,7 +3643,7 @@ zfs_ioc_rename(zfs_cmd_t *zc)
> 	} else {
> #ifdef illumos
> 		if (zc->zc_objset_type == DMU_OST_ZVOL)
>-			(void) zvol_remove_minor(zc->zc_name);
>+			(void) zvol_remove_minors(zc->zc_name);
> #endif
> 		return (dsl_dir_rename(zc->zc_name, zc->zc_value));
> 	}
>--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c.orig	2014-09-29 18:52:05.348521778 +0000
>+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c	2014-09-29 18:52:24.909520935 +0000
>@@ -630,24 +630,6 @@ zvol_remove_zv(zvol_state_t *zv)
> }
> 
> int
>-zvol_remove_minor(const char *name)
>-{
>-	zvol_state_t *zv;
>-	int rc;
>-
>-	mutex_enter(&spa_namespace_lock);
>-	if ((zv = zvol_minor_lookup(name)) == NULL) {
>-		mutex_exit(&spa_namespace_lock);
>-		return (SET_ERROR(ENXIO));
>-	}
>-	g_topology_lock();
>-	rc = zvol_remove_zv(zv);
>-	g_topology_unlock();
>-	mutex_exit(&spa_namespace_lock);
>-	return (rc);
>-}
>-
>-int
> zvol_first_open(zvol_state_t *zv)
> {
> 	objset_t *os;
>@@ -775,15 +757,17 @@ zvol_update_volsize(objset_t *os, uint64
> 	return (error);
> }
> 
>-void
>+int
> zvol_remove_minors(const char *name)
> {
> 	struct g_geom *gp, *gptmp;
> 	struct g_provider *pp;
> 	zvol_state_t *zv;
> 	size_t namelen;
>+	int rc;
> 
> 	namelen = strlen(name);
>+	rc = ENXIO;
> 
> 	DROP_GIANT();
> 	mutex_enter(&spa_namespace_lock);
>@@ -798,14 +782,18 @@ zvol_remove_minors(const char *name)
> 			continue;
> 		if (strcmp(zv->zv_name, name) == 0 ||
> 		    (strncmp(zv->zv_name, name, namelen) == 0 &&
>-		     zv->zv_name[namelen] == '/')) {
>-			(void) zvol_remove_zv(zv);
>+		    strlen(zv->zv_name) > namelen && (zv->zv_name[namelen] == '/' ||
>+		    zv->zv_name[namelen] == '@'))) {
>+			if ((rc = zvol_remove_zv(zv)) != 0)
>+				break;
> 		}
> 	}
> 
> 	g_topology_unlock();
> 	mutex_exit(&spa_namespace_lock);
> 	PICKUP_GIANT();
>+
>+	return (rc);
> }
> 
> int
>@@ -2393,9 +2381,10 @@ zvol_create_minors(const char *name)
> 	if (dmu_objset_type(os) == DMU_OST_ZVOL) {
> 		dsl_dataset_long_hold(os->os_dsl_dataset, FTAG);
> 		dsl_pool_rele(dmu_objset_pool(os), FTAG);
>-		if ((error = zvol_create_minor(name)) == 0)
>+		error = zvol_create_minor(name);
>+		if (error == 0 || error == EEXIST) {
> 			error = zvol_create_snapshots(os, name);
>-		else {
>+		} else {
> 			printf("ZFS WARNING: Unable to create ZVOL %s (error=%d).\n",
> 			    name, error);
> 		}
>@@ -2479,12 +2468,16 @@ zvol_rename_minors(const char *oldname, 
> 	size_t oldnamelen, newnamelen;
> 	zvol_state_t *zv;
> 	char *namebuf;
>+	boolean_t locked = B_FALSE;
> 
> 	oldnamelen = strlen(oldname);
> 	newnamelen = strlen(newname);
> 
> 	DROP_GIANT();
>-	mutex_enter(&spa_namespace_lock);
>+	if (!MUTEX_HELD(&spa_namespace_lock)) {
>+		mutex_enter(&spa_namespace_lock);
>+		locked = B_TRUE;
>+	}
> 	g_topology_lock();
> 
> 	LIST_FOREACH(gp, &zfs_zvol_class.geom, geom) {
>@@ -2507,6 +2500,7 @@ zvol_rename_minors(const char *oldname, 
> 	}
> 
> 	g_topology_unlock();
>-	mutex_exit(&spa_namespace_lock);
>+	if (locked)
>+		mutex_exit(&spa_namespace_lock);
> 	PICKUP_GIANT();
> }

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Attachments on bug 193803: 147905 | 147915 | 147924 | 161674