From e9037b63940e8bd79fbb939cb050a0ed105a6208 Mon Sep 17 00:00:00 2001 From: kib Date: Thu, 21 Mar 2019 13:30:48 +0000 Subject: [PATCH] nullfs: fix unmounts when filesystem is active. If vflush() did not completely flushed the mount vnodes queue, either retry for forced unmounts, or give up for non-forced. This situation can occur when new vnodes are instantiated while vflush() worked. Reported and tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week --- sys/fs/nullfs/null_vfsops.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/sys/fs/nullfs/null_vfsops.c b/sys/fs/nullfs/null_vfsops.c index fdb5e9e7e7e..361a878687d 100644 --- a/sys/fs/nullfs/null_vfsops.c +++ b/sys/fs/nullfs/null_vfsops.c @@ -235,7 +235,7 @@ nullfs_unmount(mp, mntflags) { struct null_mount *mntdata; struct mount *ump; - int error, flags; + int error, flags, rootrefs; NULLFSDEBUG("nullfs_unmount: mp = %p\n", (void *)mp); @@ -244,10 +244,20 @@ nullfs_unmount(mp, mntflags) else flags = 0; - /* There is 1 extra root vnode reference (nullm_rootvp). */ - error = vflush(mp, 1, flags, curthread); - if (error) - return (error); + for (rootrefs = 1;; rootrefs = 0) { + /* There is 1 extra root vnode reference (nullm_rootvp). */ + error = vflush(mp, rootrefs, flags, curthread); + if (error) + return (error); + MNT_ILOCK(mp); + if (mp->mnt_nvnodelistsize == 0) { + MNT_IUNLOCK(mp); + break; + } + MNT_IUNLOCK(mp); + if ((mntflags & MNT_FORCE) == 0) + return (EBUSY); + } /* * Finally, throw away the null_mount structure -- 2.45.2