[PATCH v2] nvmet: fix mismatched serial

From: zhenwei pi
Date: Sat Dec 12 2020 - 04:59:30 EST


Target side uses 'bin2hex' to convert u64 serial number to a hex
string, saving serial number as be64 to keep the right byte order.
Also use format '%016llx' to show the full serial string to avoid
to drop prefixed zero.

Test on x86 server, config '0123456789abcdef' to 'attr_serial' on
target side, and run 'nvme id-ctrl /dev/nvme0' on initiator side,
then we can get the same SN string.

Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
drivers/nvme/target/configfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 37e1d7784e17..6404b9ce09eb 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -996,8 +996,9 @@ static ssize_t nvmet_subsys_attr_serial_show(struct config_item *item,
char *page)
{
struct nvmet_subsys *subsys = to_subsys(item);
+ u64 serial = be64_to_cpu((__force __be64)subsys->serial);

- return snprintf(page, PAGE_SIZE, "%llx\n", subsys->serial);
+ return snprintf(page, PAGE_SIZE, "%016llx\n", serial);
}

static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
@@ -1009,7 +1010,7 @@ static ssize_t nvmet_subsys_attr_serial_store(struct config_item *item,
return -EINVAL;

down_write(&nvmet_config_sem);
- to_subsys(item)->serial = serial;
+ to_subsys(item)->serial = (__force u64)cpu_to_be64(serial);
up_write(&nvmet_config_sem);

return count;
--
2.25.1