linux: add possibility to disable IOCTL probing

blktests nvme/039 is assuming that the first ioctl issued is the
expected IO passthru. Though the recent introduce ioctl probing breaks
the tests. One could argue that the test should be made more robust but
it's probably a good idea to have a way to disable this feature anyway.

The obvious to way to implement this feature is to add a flag argument
to nvme_open. This works for all nvme commands but not for the nvmf
because under the hood new transport handles are created when necessary.
Since this is a global flag anyway, add it to the global context.

Signed-off-by: Daniel Wagner <[email protected]>

Author: igaw

libnvme/src/libnvme.ld

@@ -229,6 +229,7 @@ LIBNVME_2_0 {
 		nvme_set_application;
 		nvme_set_dry_run;
 		nvme_set_etdas;
+		nvme_set_ioctl_probing;
 		nvme_set_keyring;
 		nvme_set_property;
 		nvme_set_root;

libnvme/src/nvme/linux.c

@@ -46,6 +46,11 @@ void nvme_set_dry_run(struct nvme_global_ctx *ctx, bool enable)
 	ctx->dry_run = enable;
 }
 
+void nvme_set_ioctl_probing(struct nvme_global_ctx *ctx, bool enable)
+{
+	ctx->ioctl_probing = enable;
+}
+
 void nvme_transport_handle_set_submit_entry(struct nvme_transport_handle *hdl,
 		void *(*submit_entry)(struct nvme_transport_handle *hdl,
 				struct nvme_passthru_cmd *cmd))
@@ -108,9 +113,11 @@ static int __nvme_transport_handle_open_direct(struct nvme_transport_handle *hdl
 		return -EINVAL;
 	}
 
-	ret = ioctl(hdl->fd, NVME_IOCTL_ADMIN64_CMD, &dummy);
-	if (ret > 0)
-		hdl->ioctl64 = true;
+	if (hdl->ctx->ioctl_probing) {
+		ret = ioctl(hdl->fd, NVME_IOCTL_ADMIN64_CMD, &dummy);
+		if (ret > 0)
+			hdl->ioctl64 = true;
+	}
 
 	return 0;
 }

libnvme/src/nvme/linux.h

@@ -742,4 +742,16 @@ int nvme_import_tls_key_versioned(struct nvme_global_ctx *ctx,
  */
 void nvme_set_dry_run(struct nvme_global_ctx *ctx, bool enable);
 
+/**
+ * nvme_set_ioctl_probing() - Enable/disable 64-bit IOCTL probing
+ * @ctx:	struct nvme_global_ctx object
+ * @enable:	Enable/disable 64-bit IOCTL probing
+ *
+ * When IOCTL probing is enabled, a 64-bit IOCTL command is issued to
+ * figure out if the passthru interface supports it.
+ *
+ * IOCTL probing is enabled per default.
+ */
+void nvme_set_ioctl_probing(struct nvme_global_ctx *ctx, bool enable);
+
 #endif /* _LIBNVME_LINUX_H */

libnvme/src/nvme/private.h

@@ -272,6 +272,7 @@ struct nvme_global_ctx {
 	struct list_head hosts;
 	struct nvme_log log;
 	bool mi_probe_enabled;
+	bool ioctl_probing;
 	bool create_only;
 	bool dry_run;
 	struct nvme_fabric_options *options;

libnvme/src/nvme/tree.c

@@ -335,7 +335,7 @@ struct nvme_global_ctx *nvme_create_global_ctx(FILE *fp, int log_level)
 	int fd;
 
 	ctx = calloc(1, sizeof(*ctx));
-	if (!ctx) 
+	if (!ctx)
 		return NULL;
 
 	if (fp) {
@@ -353,6 +353,8 @@ struct nvme_global_ctx *nvme_create_global_ctx(FILE *fp, int log_level)
 	list_head_init(&ctx->hosts);
 	list_head_init(&ctx->endpoints);
 
+	ctx->ioctl_probing = true;
+
 	return ctx;
 }
 

nvme.c

@@ -396,6 +396,9 @@ int parse_and_open(struct nvme_global_ctx **ctx,
 	if (!ctx_new)
 		return -ENOMEM;
 
+	nvme_set_ioctl_probing(ctx_new,
+		!argconfig_parse_seen(opts, "no-ioctl-probing"));
+
 	ret = get_transport_handle(ctx_new, argc, argv, O_RDONLY, &hdl_new);
 	if (ret) {
 		nvme_free_global_ctx(ctx_new);

nvme.h

@@ -58,6 +58,7 @@ struct nvme_config {
 	__u32 timeout;
 	bool dry_run;
 	bool no_retries;
+	bool no_ioctl_probing;
 	unsigned int output_format_ver;
 };
 
@@ -73,7 +74,9 @@ struct nvme_config {
 		OPT_UINT("timeout",      't', &nvme_cfg.timeout,       timeout),       \
 		OPT_FLAG("dry-run",        0, &nvme_cfg.dry_run,       dry_run),       \
 		OPT_FLAG("no-retries",     0, &nvme_cfg.no_retries,                    \
-			 "disable retry logic on errors\n"),                           \
+			 "disable retry logic on errors"),                             \
+		OPT_FLAG("no-ioctl-probing", 0, &nvme_cfg.no_ioctl_probing,            \
+			 "disable 64-bit IOCTL support probing"),                      \
 		OPT_UINT("output-format-version", 0, &nvme_cfg.output_format_ver,      \
 			 "output format version: 1|2"),                                \
 		OPT_END()                                                              \