zvol: verify IO type is supported

ZVOLs don't support all block layer IO request types.  Add a check for
the IO types we do support.  Also, remove references to
io_is_secure_erase() since they are not supported on ZVOLs.

Signed-off-by: Tony Hutter <[email protected]>

Author: tonyhutter

module/os/linux/zfs/zvol_os.c

@@ -337,16 +337,14 @@ zvol_discard(zv_request_t *zvr)
 	}
 
 	/*
-	 * Align the request to volume block boundaries when a secure erase is
-	 * not required.  This will prevent dnode_free_range() from zeroing out
-	 * the unaligned parts which is slow (read-modify-write) and useless
-	 * since we are not freeing any space by doing so.
+	 * Align the request to volume block boundaries. This will prevent
+	 * dnode_free_range() from zeroing out the unaligned parts which is
+	 * slow (read-modify-write) and useless since we are not freeing any
+	 * space by doing so.
 	 */
-	if (!io_is_secure_erase(bio, rq)) {
-		start = P2ROUNDUP(start, zv->zv_volblocksize);
-		end = P2ALIGN_TYPED(end, zv->zv_volblocksize, uint64_t);
-		size = end - start;
-	}
+	start = P2ROUNDUP(start, zv->zv_volblocksize);
+	end = P2ALIGN_TYPED(end, zv->zv_volblocksize, uint64_t);
+	size = end - start;
 
 	if (start >= end)
 		goto unlock;
@@ -467,6 +465,18 @@ zvol_read_task(void *arg)
 	zv_request_task_free(task);
 }
 
+/*
+ * Verify the request is one of the IO types we can process (read, write, sync,
+ * trim).
+ */
+inline static boolean_t
+zvol_rq_type_is_supported(struct request *rq) {
+	return (op_is_write(rq->cmd_flags) ||
+	    req_op(rq) == REQ_OP_READ ||
+	    req_op(rq) == REQ_OP_FLUSH ||
+	    op_is_sync(rq->cmd_flags) ||
+	    op_is_discard(rq->cmd_flags));
+}
 
 /*
  * Process a BIO or request
@@ -487,6 +497,14 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 	int rw;
 
 	if (rq != NULL) {
+		if (unlikely(!zvol_rq_type_is_supported(rq))) {
+			zfs_dbgmsg("Unsupported zvol IO, op=%d, cmd=0x%x",
+			    req_op(rq), rq->cmd_flags);
+			ASSERT(zvol_rq_type_is_supported(rq));
+			zvol_end_io(bio, rq, SET_ERROR(ENOTSUPP));
+			goto out;
+		}
+
 		/*
 		 * Flush & trim requests go down the zvol_write codepath.  Or
 		 * more specifically:
@@ -610,7 +628,7 @@ zvol_request_impl(zvol_state_t *zv, struct bio *bio, struct request *rq,
 		 * interfaces lack this functionality (they block waiting for
 		 * the i/o to complete).
 		 */
-		if (io_is_discard(bio, rq) || io_is_secure_erase(bio, rq)) {
+		if (io_is_discard(bio, rq)) {
 			if (force_sync) {
 				zvol_discard(&zvr);
 			} else {

tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_trim.ksh

@@ -41,6 +41,7 @@
 # 5. TRIM the first 1MB and last 2MB of the 5MB block of data.
 # 6. Observe 2MB of used space on the zvol
 # 7. Verify the trimmed regions are zero'd on the zvol
+# 8. Verify Secure Erase does not work on zvols (Linux only)
 
 verify_runnable "global"
 
@@ -56,6 +57,7 @@ if is_linux ; then
 	else
 		trimcmd='blkdiscard'
 	fi
+	secure_trimcmd="$trimcmd --secure"
 else
 	# By default, FreeBSD 'trim' always does a dry-run.  '-f' makes
 	# it perform the actual operation.
@@ -114,6 +116,11 @@ function do_test {
 	log_must diff $datafile1 $datafile2
 
 	log_must rm $datafile1 $datafile2
+
+	# Secure erase should not work (Linux check only).
+	if [ -n "$secure_trimcmd" ] ; then
+		log_mustnot $secure_trimcmd $zvolpath
+	fi
 }
 
 log_assert "Verify that a ZFS volume can be TRIMed"