git: 080917298512 - main - unionfs: fixes to unionfs_nodeget() error handling

The branch main has been updated by jah:

URL: https://cgit.FreeBSD.org/src/commit/?id=08091729851294fe302548af3c57c51aa12692fb

commit 08091729851294fe302548af3c57c51aa12692fb
Author:     Jason A. Harmening <jah@FreeBSD.org>
AuthorDate: 2023-03-26 01:30:25 +0000
Commit:     Jason A. Harmening <jah@FreeBSD.org>
CommitDate: 2023-05-07 23:30:43 +0000

    unionfs: fixes to unionfs_nodeget() error handling
    
    If either the lower or upper vnode is found to be doomed after
    locking it, the newly-created unionfs node won't be associated
    with it and its lock will be dropped.  In that case, clear the
    uppervp and lowervp locals as necessary to avoid further use
    of the vnode in unionfs_nodeget().  If the upper vnode is doomed
    but the lower vnode remains valid, additionally reset the unionfs
    node's v_vnlock field to point to the lower vnode lock.
    
    Reviewed by:    kib, markj
    Tested by:      pho
    Differential Revision:  https://reviews.freebsd.org/D39767
---
 sys/fs/unionfs/union_subr.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/sys/fs/unionfs/union_subr.c b/sys/fs/unionfs/union_subr.c
index 264d37634949..702b10bb6204 100644
--- a/sys/fs/unionfs/union_subr.c
+++ b/sys/fs/unionfs/union_subr.c
@@ -397,13 +397,15 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	}
 	if (lowervp != NULL && VN_IS_DOOMED(lowervp)) {
 		vput(lowervp);
-		unp->un_lowervp = NULL;
+		unp->un_lowervp = lowervp = NULL;
 	}
 	if (uppervp != NULL && VN_IS_DOOMED(uppervp)) {
 		vput(uppervp);
-		unp->un_uppervp = NULL;
+		unp->un_uppervp = uppervp = NULL;
+		if (lowervp != NULLVP)
+			vp->v_vnlock = lowervp->v_vnlock;
 	}
-	if (unp->un_lowervp == NULL && unp->un_uppervp == NULL) {
+	if (lowervp == NULL && uppervp == NULL) {
 		unionfs_nodeget_cleanup(vp, unp);
 		return (ENOENT);
 	}