git: 824530a5c4fd - main - nda: Assume all cases in ndaasync can sleep

The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=824530a5c4fd59427cda0eae0a4ac85212814958

commit 824530a5c4fd59427cda0eae0a4ac85212814958
Author:     Warner Losh <imp@FreeBSD.org>
AuthorDate: 2026-03-03 18:00:15 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2026-03-03 18:00:15 +0000

    nda: Assume all cases in ndaasync can sleep
    
    The error recovery is nicer if we can wait for the tiny memory we need
    to send the messages when the physpath changes. Since we've moved the
    async handler into a sleepable context, we can wait for the allocation
    to complete since async events are rare enough and it's not an
    indefinite wait.
    
    Also add a comment about the scope of AC_ADVINFO_CHANGED for nvme
    drives. We could use it for broadcasting INDENTIFY changes in nvme
    drives. However, the underlying mechanisms in NVMe don't really allow
    for that (they are more fine-grained). So for namespace changes, for
    example, we'll send AC_GETDEV_CHANGED instead of a AC_ADVINFO_CHANGED.
    
    Sponsored by:           Netflix
    Differential Revision:  https://reviews.freebsd.org/D55523
---
 sys/cam/nvme/nvme_da.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/sys/cam/nvme/nvme_da.c b/sys/cam/nvme/nvme_da.c
index a1114ffe8a44..be578bae5da5 100644
--- a/sys/cam/nvme/nvme_da.c
+++ b/sys/cam/nvme/nvme_da.c
@@ -782,11 +782,19 @@ ndaasync(void *callback_arg, uint32_t code, struct cam_path *path, void *arg)
 	{
 		uintptr_t buftype;
 
+		/*
+		 * Note: In theory, we could send CDAI_TYPE_NVME_* events here,
+		 * but instead the rescan code only sends more specific
+		 * AC_GETDEV_CHANGED. There's no way to generically get
+		 * notifications of changes to these structures from the drive
+		 * (though we could notice with memcmp). The automation in NVME
+		 * is at a much more granular level, so we leverage that.
+		 */
 		softc = periph->softc;
 		buftype = (uintptr_t)arg;
 		if (buftype == CDAI_TYPE_PHYS_PATH) {
 			disk_attr_changed(softc->disk, "GEOM::physpath",
-			    M_NOWAIT);
+			    M_WAITOK);
 		}
 		break;
 	}