diff options
Diffstat (limited to 'sys/fs/nullfs/null_subr.c')
| -rw-r--r-- | sys/fs/nullfs/null_subr.c | 29 |
1 files changed, 18 insertions, 11 deletions
diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c index 7e3571d..5f926a6 100644 --- a/sys/fs/nullfs/null_subr.c +++ b/sys/fs/nullfs/null_subr.c @@ -67,7 +67,6 @@ struct mtx null_hashmtx; static MALLOC_DEFINE(M_NULLFSHASH, "nullfs_hash", "NULLFS hash table"); MALLOC_DEFINE(M_NULLFSNODE, "nullfs_node", "NULLFS vnode private part"); -static struct vnode * null_hashget(struct mount *, struct vnode *); static struct vnode * null_hashins(struct mount *, struct null_node *); /* @@ -98,7 +97,7 @@ nullfs_uninit(vfsp) * Return a VREF'ed alias for lower vnode if already exists, else 0. * Lower vnode should be locked on entry and will be left locked on exit. */ -static struct vnode * +struct vnode * null_hashget(mp, lowervp) struct mount *mp; struct vnode *lowervp; @@ -209,14 +208,10 @@ null_nodeget(mp, lowervp, vpp) struct vnode *vp; int error; - /* - * The insmntque1() call below requires the exclusive lock on - * the nullfs vnode. - */ - ASSERT_VOP_ELOCKED(lowervp, "lowervp"); - KASSERT(lowervp->v_usecount >= 1, ("Unreferenced vnode %p\n", lowervp)); + ASSERT_VOP_LOCKED(lowervp, "lowervp"); + KASSERT(lowervp->v_usecount >= 1, ("Unreferenced vnode %p", lowervp)); - /* Lookup the hash firstly */ + /* Lookup the hash firstly. */ *vpp = null_hashget(mp, lowervp); if (*vpp != NULL) { vrele(lowervp); @@ -224,6 +219,19 @@ null_nodeget(mp, lowervp, vpp) } /* + * The insmntque1() call below requires the exclusive lock on + * the nullfs vnode. Upgrade the lock now if hash failed to + * provide ready to use vnode. + */ + if (VOP_ISLOCKED(lowervp) != LK_EXCLUSIVE) { + vn_lock(lowervp, LK_UPGRADE | LK_RETRY); + if ((lowervp->v_iflag & VI_DOOMED) != 0) { + vput(lowervp); + return (ENOENT); + } + } + + /* * We do not serialize vnode creation, instead we will check for * duplicates later, when adding new vnode to hash. * Note that duplicate can only appear in hash if the lowervp is @@ -233,8 +241,7 @@ null_nodeget(mp, lowervp, vpp) * might cause a bogus v_data pointer to get dereferenced * elsewhere if MALLOC should block. */ - xp = malloc(sizeof(struct null_node), - M_NULLFSNODE, M_WAITOK); + xp = malloc(sizeof(struct null_node), M_NULLFSNODE, M_WAITOK); error = getnewvnode("null", mp, &null_vnodeops, &vp); if (error) { |
