Author: kib Date: Fri Aug 14 10:59:17 2009 New Revision: 196205 URL: http://svn.freebsd.org/changeset/base/196205
Log: In nfs_upgrade_vnlock(), assert that the vnode is locked. It is for all pathes, as far as I see and testing seems to confirm it. Comparision of old_lock with LK_SHARED make sense only if vnode is locked by current thread. When downgrading, pass LK_RETRY to the vn_lock(), since otherwise vn_lock() unlocks the doomed vnode, causing extra unlock. Reported and tested by: pho Approved by: re (rwatson) MFC after: 3 weeks Modified: head/sys/nfsclient/nfs_subs.c Modified: head/sys/nfsclient/nfs_subs.c ============================================================================== --- head/sys/nfsclient/nfs_subs.c Fri Aug 14 10:57:57 2009 (r196204) +++ head/sys/nfsclient/nfs_subs.c Fri Aug 14 10:59:17 2009 (r196205) @@ -409,28 +409,25 @@ int nfs_upgrade_vnlock(struct vnode *vp) { int old_lock; - - if ((old_lock = VOP_ISLOCKED(vp)) != LK_EXCLUSIVE) { - if (old_lock == LK_SHARED) { - /* Upgrade to exclusive lock, this might block */ - vn_lock(vp, LK_UPGRADE | LK_RETRY); - } else { - vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - } + + ASSERT_VOP_LOCKED(vp, "nfs_upgrade_vnlock"); + old_lock = VOP_ISLOCKED(vp); + if (old_lock != LK_EXCLUSIVE) { + KASSERT(old_lock == LK_SHARED, + ("nfs_upgrade_vnlock: wrong old_lock %d", old_lock)); + /* Upgrade to exclusive lock, this might block */ + vn_lock(vp, LK_UPGRADE | LK_RETRY); } - return old_lock; + return (old_lock); } void nfs_downgrade_vnlock(struct vnode *vp, int old_lock) { if (old_lock != LK_EXCLUSIVE) { - if (old_lock == LK_SHARED) { - /* Downgrade from exclusive lock, this might block */ - vn_lock(vp, LK_DOWNGRADE); - } else { - VOP_UNLOCK(vp, 0); - } + KASSERT(old_lock == LK_SHARED, ("wrong old_lock %d", old_lock)); + /* Downgrade from exclusive lock. */ + vn_lock(vp, LK_DOWNGRADE | LK_RETRY); } } _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"