diff options
Diffstat (limited to 'sys/kern/vfs_lookup.c')
| -rw-r--r-- | sys/kern/vfs_lookup.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c index a0cbc83..bf624d8 100644 --- a/sys/kern/vfs_lookup.c +++ b/sys/kern/vfs_lookup.c @@ -69,13 +69,18 @@ __FBSDID("$FreeBSD$"); * Allocation zone for namei */ uma_zone_t namei_zone; +/* + * Placeholder vnode for mp traversal + */ +static struct vnode *vp_crossmp; static void nameiinit(void *dummy __unused) { namei_zone = uma_zcreate("NAMEI", MAXPATHLEN, NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); - + getnewvnode("crossmp", NULL, &dead_vnodeops, &vp_crossmp); + vp_crossmp->v_vnlock->lk_flags &= ~LK_NOSHARE; } SYSINIT(vfs, SI_SUB_VFS, SI_ORDER_SECOND, nameiinit, NULL) @@ -559,7 +564,8 @@ unionlookup: * If we have a shared lock we may need to upgrade the lock for the * last operation. */ - if (VOP_ISLOCKED(dp, td) == LK_SHARED && + if (dp != vp_crossmp && + VOP_ISLOCKED(dp, td) == LK_SHARED && (cnp->cn_flags & ISLASTCN) && (cnp->cn_flags & LOCKPARENT)) vn_lock(dp, LK_UPGRADE|LK_RETRY, td); /* @@ -658,10 +664,17 @@ unionlookup: VFS_UNLOCK_GIANT(vfslocked); vfslocked = VFS_LOCK_GIANT(mp); if (dp != ndp->ni_dvp) - VOP_UNLOCK(ndp->ni_dvp, 0, td); + vput(ndp->ni_dvp); + else + vrele(ndp->ni_dvp); + VFS_UNLOCK_GIANT(dvfslocked); + dvfslocked = 0; + vref(vp_crossmp); + ndp->ni_dvp = vp_crossmp; error = VFS_ROOT(mp, compute_cn_lkflags(mp, cnp->cn_lkflags), &tdp, td); vfs_unbusy(mp, td); - vn_lock(ndp->ni_dvp, compute_cn_lkflags(mp, cnp->cn_lkflags | LK_RETRY), td); + if (vn_lock(vp_crossmp, LK_SHARED | LK_NOWAIT, td)) + panic("vp_crossmp exclusively locked or reclaimed"); if (error) { dpunlocked = 1; goto bad2; |
