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Lock down pseudofs:

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- Initialize lock structure in vncache_alloc
 - Return locked vnodes from vncache_alloc
 - Setup vnode op vectors to use default lock, unlock, and islocked
 - Implement simple locking scheme required for lookup
This commit is contained in:
Jeff Roberson 2002-07-08 01:50:14 +00:00
parent 15c3d6e567
commit 922b974a44
2 changed files with 29 additions and 0 deletions
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5
sys/fs/pseudofs/pseudofs_vncache.c
View File

@ -120,6 +120,8 @@ pfs_vncache_alloc(struct mount *mp, struct vnode **vpp,
mtx_unlock(&pfs_vncache_mutex);
/* XXX see comment at top of pfs_lookup() */
cache_purge(*vpp);
vn_lock(*vpp, LK_RETRY | LK_EXCLUSIVE,
curthread);
return (0);
}
/* XXX if this can happen, we're in trouble */
@ -171,6 +173,9 @@ pfs_vncache_alloc(struct mount *mp, struct vnode **vpp,
pvd->pvd_next->pvd_prev = pvd;
pfs_vncache = pvd;
mtx_unlock(&pfs_vncache_mutex);
(*vpp)->v_vnlock = &(*vpp)->v_lock;
lockinit((*vpp)->v_vnlock, PINOD, "pfsnod", VLKTIMEOUT, LK_CANRECURSE);
vn_lock(*vpp, LK_RETRY | LK_EXCLUSIVE, curthread);
return (0);
}

24
sys/fs/pseudofs/pseudofs_vnops.c
View File

@ -312,11 +312,15 @@ pfs_lookup(struct vop_lookup_args *va)
struct pfs_node *pd = pvd->pvd_pn;
struct pfs_node *pn, *pdn = NULL;
pid_t pid = pvd->pvd_pid;
int lockparent;
int wantparent;
char *pname;
int error, i, namelen;
PFS_TRACE(("%.*s", (int)cnp->cn_namelen, cnp->cn_nameptr));
cnp->cn_flags &= ~PDIRUNLOCK;
if (vn->v_type != VDIR)
PFS_RETURN (ENOTDIR);
@ -336,6 +340,10 @@ pfs_lookup(struct vop_lookup_args *va)
if (!pfs_visible(curthread, pd, pvd->pvd_pid))
PFS_RETURN (ENOENT);
lockparent = cnp->cn_flags & LOCKPARENT;
wantparent = cnp->cn_flags & (LOCKPARENT | WANTPARENT);
/* self */
namelen = cnp->cn_namelen;
pname = cnp->cn_nameptr;
@ -350,6 +358,9 @@ pfs_lookup(struct vop_lookup_args *va)
if (cnp->cn_flags & ISDOTDOT) {
if (pd->pn_type == pfstype_root)
PFS_RETURN (EIO);
VOP_UNLOCK(vn, 0, cnp->cn_thread);
cnp->cn_flags |= PDIRUNLOCK;
KASSERT(pd->pn_parent, ("non-root directory has no parent"));
/*
* This one is tricky. Descendents of procdir nodes
@ -390,9 +401,19 @@ pfs_lookup(struct vop_lookup_args *va)
pn->pn_parent = pd;
if (!pfs_visible(curthread, pn, pvd->pvd_pid))
PFS_RETURN (ENOENT);
error = pfs_vncache_alloc(vn->v_mount, vpp, pn, pid);
if (error)
PFS_RETURN (error);
if ((cnp->cn_flags & ISDOTDOT) && (cnp->cn_flags & ISLASTCN)
&& lockparent) {
vn_lock(vn, LK_EXCLUSIVE|LK_RETRY, cnp->cn_thread);
cnp->cn_flags &= ~PDIRUNLOCK;
}
if (!lockparent || !(cnp->cn_flags & ISLASTCN))
VOP_UNLOCK(vn, 0, cnp->cn_thread);
/*
* XXX See comment at top of the routine.
*/
@ -806,6 +827,9 @@ static struct vnodeopv_entry_desc pfs_vnodeop_entries[] = {
{ &vop_setattr_desc, (vop_t *)pfs_setattr },
{ &vop_symlink_desc, (vop_t *)vop_eopnotsupp },
{ &vop_write_desc, (vop_t *)pfs_write },
{ &vop_lock_desc, (vop_t *)vop_stdlock },
{ &vop_unlock_desc, (vop_t *)vop_stdunlock },
{ &vop_islocked_desc, (vop_t *)vop_stdislocked},
/* XXX I've probably forgotten a few that need vop_eopnotsupp */
{ NULL, (vop_t *)NULL }
};