git: 36d971464ac2 - main - geom: Make g_waitidle() wait for orphaned providers

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=36d971464ac21f6531cb9eaa377f4e1dd915a2ad

commit 36d971464ac21f6531cb9eaa377f4e1dd915a2ad
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2026-04-09 01:08:45 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2026-04-09 01:10:13 +0000

    geom: Make g_waitidle() wait for orphaned providers
    
    This is motivated by the following race in the ZFS zvol code.
    
    When a zvol is created, we create a GEOM-backed zvol, which results in a
    /dev/zvol/<zvol path> device file, created by GEOM::dev.  If volmode=dev
    is specified, zvol_set_volmode_impl() will wither the GEOM, then create
    a device file with the same name.  This sometimes fails because
    g_wither_geom() is asynchronous, so we end up trying to create a device
    file while the old one still exists.  I want to fix this by adding a
    g_waitidle() call to zvol_os_remove_minor().
    
    g_waitidle() is not sufficient: GEOM::dev does not destroy the device
    until g_dev_orphan() is called.  (In fact the device destruction is
    asynchronous too, but the delist_dev() call is sufficient to address
    this race.)  So, I propose modifying g_waitidle() to block until
    orphaned providers are processed.
    
    PR:             258766
    Reviewed by:    mav, imp, kib
    MFC after:      2 weeks
    Differential Revision:  https://reviews.freebsd.org/D55049
---
 sys/geom/geom_event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/geom/geom_event.c b/sys/geom/geom_event.c
index ffd46db55416..34649cea5a71 100644
--- a/sys/geom/geom_event.c
+++ b/sys/geom/geom_event.c
@@ -84,7 +84,7 @@ g_waitidle(struct thread *td)
 
 	mtx_lock(&g_eventlock);
 	TSWAIT("GEOM events");
-	while (!TAILQ_EMPTY(&g_events))
+	while (!TAILQ_EMPTY(&g_events) || !TAILQ_EMPTY(&g_doorstep))
 		msleep(&g_pending_events, &g_eventlock, PPAUSE,
 		    "g_waitidle", 0);
 	TSUNWAIT("GEOM events");