Commit 7ae023c5 authored by Noam Gottlieb's avatar Noam Gottlieb Committed by Christoph Hellwig
Browse files

nvmet: make sn stable once connection was established 



Once some host has connected to the target, make sure that the serial
number is stable and cannot be changed.

Reviewed-by: default avatarMax Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: default avatarNoam Gottlieb <ngottlieb@nvidia.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent e13b0615

drivers/nvme/target/admin-cmd.c

+6 −0
Original line number Diff line number Diff line
@@ -337,6 +337,12 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req) 
	u32 cmd_capsule_size;

	u16 status = 0;



	if (!subsys->subsys_discovered) {

		mutex_lock(&subsys->lock);

		subsys->subsys_discovered = true;

		mutex_unlock(&subsys->lock);

	}



	/*

	 * If there is no model number yet, set it now.  It will then remain

	 * stable for the life time of the subsystem.

drivers/nvme/target/configfs.c

+22 −5
Original line number Diff line number Diff line
@@ -1044,12 +1044,18 @@ static ssize_t nvmet_subsys_attr_serial_show(struct config_item *item, 
	return snprintf(page, PAGE_SIZE, "%s\n", subsys->serial);

}



static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,

static ssize_t

nvmet_subsys_attr_serial_store_locked(struct nvmet_subsys *subsys,

		const char *page, size_t count)

{

	struct nvmet_subsys *subsys = to_subsys(item);

	int pos, len = strcspn(page, "\n");



	if (subsys->subsys_discovered) {

		pr_err("Can't set serial number. %s is already assigned\n",

		       subsys->serial);

		return -EINVAL;

	}



	if (!len || len > NVMET_SN_MAX_SIZE) {

		pr_err("Serial Number can not be empty or exceed %d Bytes\n",

		       NVMET_SN_MAX_SIZE);
@@ -1063,13 +1069,24 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item, 
		}

	}



	memcpy_and_pad(subsys->serial, NVMET_SN_MAX_SIZE, page, len, ' ');



	return count;

}



static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,

					      const char *page, size_t count)

{

	struct nvmet_subsys *subsys = to_subsys(item);

	ssize_t ret;



	down_write(&nvmet_config_sem);

	mutex_lock(&subsys->lock);

	memcpy_and_pad(subsys->serial, NVMET_SN_MAX_SIZE, page, len, ' ');

	ret = nvmet_subsys_attr_serial_store_locked(subsys, page, count);

	mutex_unlock(&subsys->lock);

	up_write(&nvmet_config_sem);



	return count;

	return ret;

}

CONFIGFS_ATTR(nvmet_subsys_, attr_serial);

drivers/nvme/target/nvmet.h

+1 −0
Original line number Diff line number Diff line
@@ -231,6 +231,7 @@ struct nvmet_subsys { 


	u64			ver;

	char			serial[NVMET_SN_MAX_SIZE];

	bool			subsys_discovered;

	char			*subsysnqn;

	bool			pi_support;