Date: Fri, 27 Aug 2021 15:39:59 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 7c1e4aab7934 - main - vfs_hash_insert: ensure that predicate is true Message-ID: <202108271539.17RFdxfP089236@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=7c1e4aab7934933f0669c2b922976b30ed628a3f commit 7c1e4aab7934933f0669c2b922976b30ed628a3f Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-08-17 13:47:25 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-08-27 15:39:45 +0000 vfs_hash_insert: ensure that predicate is true After vnode lock, recheck v_hash. When vfs_hash_insert() is used with a predicate, recheck it after the selected vnode is locked. Since vfs_hash_lock is dropped, vnode could be rehashed during the sleep for the vnode lock, which could go unnoticed there. Reported and tested by: pho Reviewed by: mckusick, rmacklem Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D31464 --- sys/kern/vfs_hash.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/sys/kern/vfs_hash.c b/sys/kern/vfs_hash.c index e10e9b57e316..c5d67c8b2b33 100644 --- a/sys/kern/vfs_hash.c +++ b/sys/kern/vfs_hash.c @@ -93,8 +93,14 @@ vfs_hash_get(const struct mount *mp, u_int hash, int flags, struct thread *td, error = vget_finish(vp, flags, vs); if (error == ENOENT && (flags & LK_NOWAIT) == 0) break; - if (error) + if (error != 0) return (error); + if (vp->v_hash != hash || + (fn != NULL && fn(vp, arg))) { + vput(vp); + /* Restart the bucket walk. */ + break; + } *vpp = vp; return (0); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202108271539.17RFdxfP089236>