NAS-125539 / None / [stable/dragonfish] Block Cloning Fixes and ZVOL Patch Backports

include/os/freebsd/spl/sys/debug.h

@@ -39,12 +39,14 @@
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
+ * ASSERT0P()	- Assert pointer is null, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
+ * VERIFY0P()	- Verify pointer is null, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
@@ -136,6 +138,15 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    (long long) (_verify3_right));			\
 	} while (0)
 
+#define	VERIFY0P(RIGHT)	do {						\
+		const uintptr_t _verify0_right = (uintptr_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
+		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
+		    "VERIFY0P(" #RIGHT ") "				\
+		    "failed (NULL == %p)\n",				\
+		    (void *)_verify0_right);				\
+	} while (0)
+
 /*
  * Debugging disabled (--disable-debug)
  */
@@ -151,6 +162,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
 	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 #define	EQUIV(A, B)		\
@@ -166,6 +178,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	IMPLY(A, B) \
 	((void)(likely((!(A)) || (B)) ||				\

include/os/linux/spl/sys/debug.h

@@ -34,12 +34,14 @@
  * ASSERT3U()	- Assert unsigned X OP Y is true, if not panic.
  * ASSERT3P()	- Assert pointer X OP Y is true, if not panic.
  * ASSERT0()	- Assert value is zero, if not panic.
+ * ASSERT0P()	- Assert pointer is null, if not panic.
  * VERIFY()	- Verify X is true, if not panic.
  * VERIFY3B()	- Verify boolean X OP Y is true, if not panic.
  * VERIFY3S()	- Verify signed X OP Y is true, if not panic.
  * VERIFY3U()	- Verify unsigned X OP Y is true, if not panic.
  * VERIFY3P()	- Verify pointer X OP Y is true, if not panic.
  * VERIFY0()	- Verify value is zero, if not panic.
+ * VERIFY0P()	- Verify pointer is null, if not panic.
  */
 
 #ifndef _SPL_DEBUG_H
@@ -140,6 +142,15 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 		    (long long) (_verify3_right));			\
 	} while (0)
 
+#define	VERIFY0P(RIGHT)	do {						\
+		const uintptr_t _verify0_right = (uintptr_t)(RIGHT);	\
+		if (unlikely(!(0 == _verify0_right)))			\
+		    spl_panic(__FILE__, __FUNCTION__, __LINE__,		\
+		    "VERIFY0P(" #RIGHT ") "				\
+		    "failed (NULL == %px)\n",				\
+		    (void *)_verify0_right);				\
+	} while (0)
+
 #define	VERIFY_IMPLY(A, B) \
 	((void)(likely((!(A)) || (B)) ||				\
 	    spl_assert("(" #A ") implies (" #B ")",			\
@@ -165,6 +176,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
 	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 #define	EQUIV(A, B)		\
@@ -180,6 +192,7 @@ spl_assert(const char *buf, const char *file, const char *func, int line)
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	IMPLY		VERIFY_IMPLY
 #define	EQUIV		VERIFY_EQUIV

include/sys/fs/zfs.h

@@ -191,6 +191,7 @@ typedef enum {
 	ZFS_PROP_REDACTED,
 	ZFS_PROP_REDACT_SNAPS,
 	ZFS_PROP_SNAPSHOTS_CHANGED,
+	ZFS_PROP_VOLTHREADING,
 	ZFS_NUM_PROPS
 } zfs_prop_t;
 

include/sys/zvol.h

@@ -50,8 +50,9 @@ extern int zvol_get_stats(objset_t *, nvlist_t *);
 extern boolean_t zvol_is_zvol(const char *);
 extern void zvol_create_cb(objset_t *, void *, cred_t *, dmu_tx_t *);
 extern int zvol_set_volsize(const char *, uint64_t);
-extern int zvol_set_snapdev(const char *, zprop_source_t, uint64_t);
-extern int zvol_set_volmode(const char *, zprop_source_t, uint64_t);
+extern int zvol_set_volthreading(const char *, boolean_t);
+extern int zvol_set_common(const char *, zfs_prop_t, zprop_source_t, uint64_t);
+extern int zvol_set_ro(const char *, boolean_t);
 extern zvol_state_handle_t *zvol_suspend(const char *);
 extern int zvol_resume(zvol_state_handle_t *);
 extern void *zvol_tag(zvol_state_handle_t *);

include/sys/zvol_impl.h

@@ -58,6 +58,7 @@ typedef struct zvol_state {
 	atomic_t		zv_suspend_ref;	/* refcount for suspend */
 	krwlock_t		zv_suspend_lock;	/* suspend lock */
 	struct zvol_state_os	*zv_zso;	/* private platform state */
+	boolean_t		zv_threading;	/* volthreading property */
 } zvol_state_t;
 
 

lib/libspl/include/assert.h

@@ -120,6 +120,15 @@ do {									\
 		    (u_longlong_t)__left);				\
 } while (0)
 
+#define	VERIFY0P(LEFT)							\
+do {									\
+	const uintptr_t __left = (uintptr_t)(LEFT);			\
+	if (!(__left == 0))						\
+		libspl_assertf(__FILE__, __FUNCTION__, __LINE__,	\
+		    "%s == 0 (%p == 0)", #LEFT,				\
+		    (void *)__left);					\
+} while (0)
+
 #ifdef assert
 #undef assert
 #endif
@@ -134,6 +143,7 @@ do {									\
 #define	ASSERT3P(x, y, z)						\
 	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
 #define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT0P(x)		((void) sizeof ((uintptr_t)(x)))
 #define	ASSERT(x)		((void) sizeof ((uintptr_t)(x)))
 #define	assert(x)		((void) sizeof ((uintptr_t)(x)))
 #define	IMPLY(A, B)							\
@@ -146,6 +156,7 @@ do {									\
 #define	ASSERT3U	VERIFY3U
 #define	ASSERT3P	VERIFY3P
 #define	ASSERT0		VERIFY0
+#define	ASSERT0P	VERIFY0P
 #define	ASSERT		VERIFY
 #define	assert		VERIFY
 #define	IMPLY(A, B) \

lib/libzfs/libzfs.abi

@@ -1867,7 +1867,8 @@
       <enumerator name='ZFS_PROP_REDACTED' value='93'/>
       <enumerator name='ZFS_PROP_REDACT_SNAPS' value='94'/>
       <enumerator name='ZFS_PROP_SNAPSHOTS_CHANGED' value='95'/>
-      <enumerator name='ZFS_NUM_PROPS' value='96'/>
+      <enumerator name='ZFS_PROP_VOLTHREADING' value='96'/>
+      <enumerator name='ZFS_NUM_PROPS' value='97'/>
     </enum-decl>
     <typedef-decl name='zfs_prop_t' type-id='4b000d60' id='58603c44'/>
     <enum-decl name='zprop_source_t' naming-typedef-id='a2256d42' id='5903f80e'>

man/man7/zfsprops.7

@@ -1192,6 +1192,18 @@ are equivalent to the
 and
 .Sy noexec
 mount options.
+.It Sy volthreading Ns = Ns Sy on Ns | Ns Sy off
+Controls internal zvol threading.
+The value
+.Sy off
+disables zvol threading, and zvol relies on application threads.
+The default value is
+.Sy on ,
+which enables threading within a zvol.
+Please note that this property will be overridden by
+.Sy zvol_request_sync
+module parameter.
+This property is only applicable to Linux.
 .It Sy filesystem_limit Ns = Ns Ar count Ns | Ns Sy none
 Limits the number of filesystems and volumes that can exist under this point in
 the dataset tree.

module/os/linux/zfs/zvol_os.c

@@ -512,7 +512,7 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 	uint64_t size = io_size(bio, rq);
 	int rw = io_data_dir(bio, rq);
 
-	if (zvol_request_sync)
+	if (zvol_request_sync || zv->zv_threading == B_FALSE)
 		force_sync = 1;
 
 	zv_request_t zvr = {
@@ -1304,6 +1304,7 @@ zvol_os_create_minor(const char *name)
 	int error = 0;
 	int idx;
 	uint64_t hash = zvol_name_hash(name);
+	uint64_t volthreading;
 	bool replayed_zil = B_FALSE;
 
 	if (zvol_inhibit_dev)
@@ -1350,6 +1351,12 @@ zvol_os_create_minor(const char *name)
 	zv->zv_volsize = volsize;
 	zv->zv_objset = os;
 
+	/* Default */
+	zv->zv_threading = B_TRUE;
+	if (dsl_prop_get_integer(name, "volthreading", &volthreading, NULL)
+	    == 0)
+		zv->zv_threading = volthreading;
+
 	set_capacity(zv->zv_zso->zvo_disk, zv->zv_volsize >> 9);
 
 	blk_queue_max_hw_sectors(zv->zv_zso->zvo_queue,

module/zcommon/zfs_prop.c

@@ -611,6 +611,9 @@ zfs_prop_init(void)
 	    ZVOL_DEFAULT_BLOCKSIZE, PROP_ONETIME,
 	    ZFS_TYPE_VOLUME, "512 to 128k, power of 2",	"VOLBLOCK", B_FALSE,
 	    sfeatures);
+	zprop_register_index(ZFS_PROP_VOLTHREADING, "volthreading",
+	    1, PROP_DEFAULT, ZFS_TYPE_VOLUME, "on | off", "zvol threading",
+	    boolean_table, sfeatures);
 	zprop_register_number(ZFS_PROP_USEDSNAP, "usedbysnapshots", 0,
 	    PROP_READONLY, ZFS_TYPE_FILESYSTEM | ZFS_TYPE_VOLUME, "<size>",
 	    "USEDSNAP", B_FALSE, sfeatures);

module/zfs/dbuf.c

@@ -1904,7 +1904,6 @@ dbuf_unoverride(dbuf_dirty_record_t *dr)
 	dmu_buf_impl_t *db = dr->dr_dbuf;
 	blkptr_t *bp = &dr->dt.dl.dr_overridden_by;
 	uint64_t txg = dr->dr_txg;
-	boolean_t release;
 
 	ASSERT(MUTEX_HELD(&db->db_mtx));
 	/*
@@ -1925,7 +1924,10 @@ dbuf_unoverride(dbuf_dirty_record_t *dr)
 	if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite)
 		zio_free(db->db_objset->os_spa, txg, bp);
 
-	release = !dr->dt.dl.dr_brtwrite;
+	if (dr->dt.dl.dr_brtwrite) {
+		ASSERT0P(dr->dt.dl.dr_data);
+		dr->dt.dl.dr_data = db->db_buf;
+	}
 	dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
 	dr->dt.dl.dr_nopwrite = B_FALSE;
 	dr->dt.dl.dr_brtwrite = B_FALSE;
@@ -1939,7 +1941,7 @@ dbuf_unoverride(dbuf_dirty_record_t *dr)
 	 * the buf thawed to save the effort of freezing &
 	 * immediately re-thawing it.
 	 */
-	if (release)
+	if (dr->dt.dl.dr_data)
 		arc_release(dr->dt.dl.dr_data, db);
 }
 
@@ -2930,7 +2932,8 @@ dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
 	while (db->db_state == DB_READ || db->db_state == DB_FILL)
 		cv_wait(&db->db_changed, &db->db_mtx);
 
-	ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED);
+	ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED ||
+	    db->db_state == DB_NOFILL);
 
 	if (db->db_state == DB_CACHED &&
 	    zfs_refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
@@ -2967,6 +2970,15 @@ dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
 			arc_buf_destroy(db->db_buf, db);
 		}
 		db->db_buf = NULL;
+	} else if (db->db_state == DB_NOFILL) {
+		/*
+		 * We will be completely replacing the cloned block.  In case
+		 * it was cloned in this transaction group, let's undirty the
+		 * pending clone and mark the block as uncached. This will be
+		 * as if the clone was never done.
+		 */
+		VERIFY(!dbuf_undirty(db, tx));
+		db->db_state = DB_UNCACHED;
 	}
 	ASSERT(db->db_buf == NULL);
 	dbuf_set_data(db, buf);

module/zfs/zfs_ioctl.c

@@ -2523,11 +2523,27 @@ zfs_prop_set_special(const char *dsname, zprop_source_t source,
 	case ZFS_PROP_VOLSIZE:
 		err = zvol_set_volsize(dsname, intval);
 		break;
-	case ZFS_PROP_SNAPDEV:
-		err = zvol_set_snapdev(dsname, source, intval);
+	case ZFS_PROP_VOLTHREADING:
+		err = zvol_set_volthreading(dsname, intval);
+		/*
+		 * Set err to -1 to force the zfs_set_prop_nvlist code down the
+		 * default path to set the value in the nvlist.
+		 */
+		if (err == 0)
+			err = -1;
 		break;
+	case ZFS_PROP_SNAPDEV:
 	case ZFS_PROP_VOLMODE:
-		err = zvol_set_volmode(dsname, source, intval);
+		err = zvol_set_common(dsname, prop, source, intval);
+		break;
+	case ZFS_PROP_READONLY:
+		err = zvol_set_ro(dsname, intval);
+		/*
+		 * Set err to -1 to force the zfs_set_prop_nvlist code down the
+		 * default path to set the value in the nvlist.
+		 */
+		if (err == 0)
+			err = -1;
 		break;
 	case ZFS_PROP_VERSION:
 	{