nvmet: don't report 0-bytes in serial number

commit 42de82a8b544fa55670feef7d6f85085fba48fc0 upstream.

The NVME standard mandates that the SN, MN, and FR fields of the Identify
Controller Data Structure be "ASCII strings".  That means that they may
not contain 0-bytes, not even string terminators.

Signed-off-by: Martin Wilck <mwilck@suse.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
[hch: fixed for the move of the serial field, updated description]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 347a1ec..5cddab5 100644 (file)
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -166,11 +166,21 @@ out:
        nvmet_req_complete(req, status);
 }
 
+static void copy_and_pad(char *dst, int dst_len, const char *src, int src_len)
+{
+       int len = min(src_len, dst_len);
+
+       memcpy(dst, src, len);
+       if (dst_len > len)
+               memset(dst + len, ' ', dst_len - len);
+}
+
 static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 {
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvme_id_ctrl *id;
        u16 status = 0;
+       const char model[] = "Linux";
 
        id = kzalloc(sizeof(*id), GFP_KERNEL);
        if (!id) {
@@ -182,8 +192,10 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
        id->vid = 0;
        id->ssvid = 0;
 
-       memset(id->sn, ' ', sizeof(id->sn));
-       snprintf(id->sn, sizeof(id->sn), "%llx", ctrl->subsys->serial);
+       bin2hex(id->sn, &ctrl->subsys->serial,
+               min(sizeof(ctrl->subsys->serial), sizeof(id->sn) / 2));
+       copy_and_pad(id->mn, sizeof(id->mn), model, sizeof(model) - 1);
+       copy_and_pad(id->fr, sizeof(id->fr), UTS_RELEASE, strlen(UTS_RELEASE));
 
        memset(id->mn, ' ', sizeof(id->mn));
        strncpy((char *)id->mn, "Linux", sizeof(id->mn));