diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2021-08-17 13:47:25 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2021-08-27 15:39:45 +0000 |
| commit | 7c1e4aab7934933f0669c2b922976b30ed628a3f (patch) | |
| tree | ee2117ff8451c0990f92c709f70d50df6b33dc1f /sys/kern/vfs_hash.c | |
| parent | 85fb840ebf3c213e45939188303bd5fe0aca4422 (diff) | |
| download | src-7c1e4aab7934933f0669c2b922976b30ed628a3f.tar.gz src-7c1e4aab7934933f0669c2b922976b30ed628a3f.zip | |
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
Diffstat (limited to 'sys/kern/vfs_hash.c')
| -rw-r--r-- | sys/kern/vfs_hash.c | 8 |
1 files changed, 7 insertions, 1 deletions
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); } |