diff --git a/sys/cam/ctl/ctl_backend_block.c b/sys/cam/ctl/ctl_backend_block.c
index 2d3c368bf83..0cce29f3979 100644
--- a/sys/cam/ctl/ctl_backend_block.c
+++ b/sys/cam/ctl/ctl_backend_block.c
@@ -501,6 +501,8 @@ ctl_be_block_biodone(struct bio *bio)
 	if (beio->num_errors > 0) {
 		if (error == EOPNOTSUPP) {
 			ctl_set_invalid_opcode(&io->scsiio);
+		} else if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
 		} else if (beio->bio_cmd == BIO_FLUSH) {
 			/* XXX KDM is there is a better error here? */
 			ctl_set_internal_failure(&io->scsiio,
@@ -711,14 +713,12 @@ ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
 		char path_str[32];
 
 		ctl_scsi_path_string(io, path_str, sizeof(path_str));
-		/*
-		 * XXX KDM ZFS returns ENOSPC when the underlying
-		 * filesystem fills up.  What kind of SCSI error should we
-		 * return for that?
-		 */
 		printf("%s%s command returned errno %d\n", path_str,
 		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
-		ctl_set_medium_error(&io->scsiio);
+		if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
+		} else
+			ctl_set_medium_error(&io->scsiio);
 		ctl_complete_beio(beio);
 		return;
 	}
@@ -804,7 +804,10 @@ ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
 	 * return the I/O to the user.
 	 */
 	if (error != 0) {
-		ctl_set_medium_error(&io->scsiio);
+		if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
+		} else
+			ctl_set_medium_error(&io->scsiio);
 		ctl_complete_beio(beio);
 		return;
 	}
diff --git a/sys/cam/ctl/ctl_error.c b/sys/cam/ctl/ctl_error.c
index d2edb2a9571..b6a8b89d133 100644
--- a/sys/cam/ctl/ctl_error.c
+++ b/sys/cam/ctl/ctl_error.c
@@ -805,6 +805,18 @@ ctl_set_task_aborted(struct ctl_scsiio *ctsio)
 	ctsio->io_hdr.status = CTL_CMD_ABORTED;
 }
 
+void
+ctl_set_space_alloc_fail(struct ctl_scsiio *ctsio)
+{
+	/* "Space allocation failed write protect" */
+	ctl_set_sense(ctsio,
+		      /*current_error*/ 1,
+		      /*sense_key*/ SSD_KEY_DATA_PROTECT,
+		      /*asc*/ 0x27,
+		      /*ascq*/ 0x07,
+		      SSD_ELEM_NONE);
+}
+
 void
 ctl_set_success(struct ctl_scsiio *ctsio)
 {
diff --git a/sys/cam/ctl/ctl_error.h b/sys/cam/ctl/ctl_error.h
index 034d14bff99..d7d82aa392a 100644
--- a/sys/cam/ctl/ctl_error.h
+++ b/sys/cam/ctl/ctl_error.h
@@ -81,6 +81,7 @@ void ctl_set_reservation_conflict(struct ctl_scsiio *ctsio);
 void ctl_set_queue_full(struct ctl_scsiio *ctsio);
 void ctl_set_busy(struct ctl_scsiio *ctsio);
 void ctl_set_task_aborted(struct ctl_scsiio *ctsio);
+void ctl_set_space_alloc_fail(struct ctl_scsiio *ctsio);
 void ctl_set_success(struct ctl_scsiio *ctsio);
 
 #endif	/* _CTL_ERROR_H_ */
diff --git a/sys/cam/scsi/scsi_all.c b/sys/cam/scsi/scsi_all.c
index d61d4522163..959eda9125a 100644
--- a/sys/cam/scsi/scsi_all.c
+++ b/sys/cam/scsi/scsi_all.c
@@ -1733,7 +1733,7 @@ static struct asc_table_entry asc_table[] = {
 	{ SST(0x27, 0x06, SS_RDEF,	/* XXX TBD */
 	    "Conditional write protect") },
 	/* D         B    */
-	{ SST(0x27, 0x07, SS_RDEF,	/* XXX TBD */
+	{ SST(0x27, 0x07, SS_FATAL | ENOSPC,
 	    "Space allocation failed write protect") },
 	/* DTLPWROMAEBKVF */
 	{ SST(0x28, 0x00, SS_FATAL | ENXIO,