git: 465c30c4f202 - stable/14 - nvme: add support for DIOCGIDENT

From: Alan Somers <asomers_at_FreeBSD.org>
Date: Sat, 22 Nov 2025 15:00:20 UTC
The branch stable/14 has been updated by asomers:

URL: https://cgit.FreeBSD.org/src/commit/?id=465c30c4f202b02cd9cb12f12d9ea856c84c5203

commit 465c30c4f202b02cd9cb12f12d9ea856c84c5203
Author:     Alan Somers <asomers@FreeBSD.org>
AuthorDate: 2025-10-16 22:00:14 +0000
Commit:     Alan Somers <asomers@FreeBSD.org>
CommitDate: 2025-11-22 14:59:24 +0000

    nvme: add support for DIOCGIDENT
    
    Add support for the DIOCGIDENT ioctl to both nvme controller device
    nodes and namespace device nodes.
    
    This information was already available via the nda(4) device node.
    However, mapping /dev/nvmeX to /dev/ndaY device nodes is not
    straightforward, so it's better to get it directly from the /dev/nvme
    device node.
    
    PR:             290259
    Sponsored by:   ConnectWise
    Submitted by:   imp (mostly)
    Pull Request:   https://github.com/freebsd/freebsd-src/pull/1875
    
    (cherry picked from commit 6d0001d44490becdd20d627ce663c72a30b9aac3)
---
 sys/dev/nvme/nvme_ctrlr.c   | 24 ++++++++++++++++++++++++
 sys/dev/nvme/nvme_ns.c      |  5 +++++
 sys/dev/nvme/nvme_private.h |  1 +
 3 files changed, 30 insertions(+)

diff --git a/sys/dev/nvme/nvme_ctrlr.c b/sys/dev/nvme/nvme_ctrlr.c
index ce203e2869fd..19fd4e70666e 100644
--- a/sys/dev/nvme/nvme_ctrlr.c
+++ b/sys/dev/nvme/nvme_ctrlr.c
@@ -35,6 +35,7 @@
 #include <sys/buf.h>
 #include <sys/bus.h>
 #include <sys/conf.h>
+#include <sys/disk.h>
 #include <sys/ioccom.h>
 #include <sys/proc.h>
 #include <sys/smp.h>
@@ -1229,6 +1230,24 @@ nvme_ctrlr_poll(struct nvme_controller *ctrlr)
 			nvme_qpair_process_completions(&ctrlr->ioq[i]);
 }
 
+/*
+ * Copy the NVME device's serial number to the provided buffer, which must be
+ * at least DISK_IDENT_SIZE bytes large.
+ */
+void
+nvme_ctrlr_get_ident(const struct nvme_controller *ctrlr, uint8_t *sn)
+{
+	_Static_assert(NVME_SERIAL_NUMBER_LENGTH < DISK_IDENT_SIZE,
+		"NVME serial number too big for disk ident");
+
+	memmove(sn, ctrlr->cdata.sn, NVME_SERIAL_NUMBER_LENGTH);
+	sn[NVME_SERIAL_NUMBER_LENGTH] = '\0';
+	for (int i = 0; sn[i] != '\0'; i++) {
+		if (sn[i] < 0x20 || sn[i] >= 0x80)
+			sn[i] = ' ';
+	}
+}
+
 /*
  * Poll the single-vector interrupt case: num_io_queues will be 1 and
  * there's only a single vector. While we're polling, we mask further
@@ -1367,6 +1386,11 @@ nvme_ctrlr_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
 	case NVME_GET_MAX_XFER_SIZE:
 		*(uint64_t *)arg = ctrlr->max_xfer_size;
 		break;
+	case DIOCGIDENT: {
+		uint8_t *sn = arg;
+		nvme_ctrlr_get_ident(ctrlr, sn);
+		break;
+	}
 	default:
 		return (ENOTTY);
 	}
diff --git a/sys/dev/nvme/nvme_ns.c b/sys/dev/nvme/nvme_ns.c
index 9eb808f81a48..1e9c5360f15c 100644
--- a/sys/dev/nvme/nvme_ns.c
+++ b/sys/dev/nvme/nvme_ns.c
@@ -89,6 +89,11 @@ nvme_ns_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int flag,
 		gnsid->nsid = ns->id;
 		break;
 	}
+	case DIOCGIDENT: {
+		uint8_t *sn = arg;
+		nvme_ctrlr_get_ident(ctrlr, sn);
+		break;
+	}
 	case DIOCGMEDIASIZE:
 		*(off_t *)arg = (off_t)nvme_ns_get_size(ns);
 		break;
diff --git a/sys/dev/nvme/nvme_private.h b/sys/dev/nvme/nvme_private.h
index 93833672674a..3039dcf40373 100644
--- a/sys/dev/nvme/nvme_private.h
+++ b/sys/dev/nvme/nvme_private.h
@@ -561,6 +561,7 @@ void	nvme_notify_new_controller(struct nvme_controller *ctrlr);
 void	nvme_notify_ns(struct nvme_controller *ctrlr, int nsid);
 
 void	nvme_ctrlr_shared_handler(void *arg);
+void	nvme_ctrlr_get_ident(const struct nvme_controller *ctrlr, uint8_t *sn);
 void	nvme_ctrlr_poll(struct nvme_controller *ctrlr);
 
 int	nvme_ctrlr_suspend(struct nvme_controller *ctrlr);