diff options
Diffstat (limited to 'sys/nfs/nfs_node.c')
| -rw-r--r-- | sys/nfs/nfs_node.c | 36 |
1 files changed, 27 insertions, 9 deletions
diff --git a/sys/nfs/nfs_node.c b/sys/nfs/nfs_node.c index 70ccacb047d..2fcfcf3c7ed 100644 --- a/sys/nfs/nfs_node.c +++ b/sys/nfs/nfs_node.c @@ -1,4 +1,4 @@ -/* $OpenBSD: nfs_node.c,v 1.47 2009/08/11 17:06:11 thib Exp $ */ +/* $OpenBSD: nfs_node.c,v 1.48 2009/08/14 17:52:18 thib Exp $ */ /* $NetBSD: nfs_node.c,v 1.16 1996/02/18 11:53:42 fvdl Exp $ */ /* @@ -83,7 +83,7 @@ nfs_nget(struct mount *mnt, nfsfh_t *fh, int fhsize, struct nfsnode **npp) { extern int (**nfsv2_vnodeop_p)(void *); /* XXX */ struct nfsmount *nmp; - struct nfsnode *np, find; + struct nfsnode *np, find, *np2; struct vnode *vp, *nvp; struct proc *p = curproc; /* XXX */ int error; @@ -91,28 +91,43 @@ nfs_nget(struct mount *mnt, nfsfh_t *fh, int fhsize, struct nfsnode **npp) nmp = VFSTONFS(mnt); loop: - /* XXXTHIB: locking. */ + rw_enter_write(&nfs_hashlock); find.n_fhp = fh; find.n_fhsize = fhsize; np = RB_FIND(nfs_nodetree, &nmp->nm_ntree, &find); if (np != NULL) { + rw_exit_write(&nfs_hashlock); vp = NFSTOV(np); - if (vget(vp, LK_EXCLUSIVE, p)) + error = vget(vp, LK_EXCLUSIVE, p); + if (error) goto loop; *npp = np; return (0); } - if (rw_enter(&nfs_hashlock, RW_WRITE|RW_SLEEPFAIL)) - goto loop; - + /* + * getnewvnode() could recycle a vnode, potentially formerly + * owned by NFS. This will cause a VOP_RECLAIM() to happen, + * which will cause recursive locking, so we unlock before + * calling getnewvnode() lock again afterwards, but must check + * to see if this nfsnode has been added while we did not hold + * the lock. + */ + rw_exit_write(&nfs_hashlock); error = getnewvnode(VT_NFS, mnt, nfsv2_vnodeop_p, &nvp); + rw_enter_write(&nfs_hashlock); if (error) { *npp = NULL; - rw_exit(&nfs_hashlock); + rw_exit_write(&nfs_hashlock); return (error); } + np = RB_FIND(nfs_nodetree, &nmp->nm_ntree, &find); + if (np != NULL) { + rw_exit_write(&nfs_hashlock); + goto loop; + } + vp = nvp; np = pool_get(&nfs_node_pool, PR_WAITOK | PR_ZERO); vp->v_data = np; @@ -133,7 +148,8 @@ loop: np->n_fhp = &np->n_fh; bcopy(fh, np->n_fhp, fhsize); np->n_fhsize = fhsize; - RB_INSERT(nfs_nodetree, &nmp->nm_ntree, np); + np2 = RB_INSERT(nfs_nodetree, &nmp->nm_ntree, np); + KASSERT(np2 == NULL); np->n_accstamp = -1; rw_exit(&nfs_hashlock); *npp = np; @@ -190,7 +206,9 @@ nfs_reclaim(void *v) vprint("nfs_reclaim: pushing active", vp); #endif + rw_enter_write(&nfs_hashlock); RB_REMOVE(nfs_nodetree, &nmp->nm_ntree, np); + rw_exit_write(&nfs_hashlock); if (np->n_rcred) crfree(np->n_rcred); |