d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- Don't acquire the vnode interlock in _vn_lock() unless no lock type

Browse Source 
is requested.  Handle this case specially before the while loop.
 - Use the held vnode lock to check for VI_DOOMED.  The vnode lock and
   interlock must both be held to set VI_DOOMED so either one held, even
   shared, is sufficient to check it.

No objection by:	kib
This commit is contained in:
Jeff Roberson 2008-03-24 04:17:35 +00:00
parent 97735db712
commit 804e60d4cf
1 changed files with 13 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
sys/kern/vfs_vnops.c
View File

@ -862,27 +862,21 @@ _vn_lock(struct vnode *vp, int flags, char *file, int line)
{ {
int error; int error;
do { /*
* With no lock type requested we're just polling for validity.
*/
if ((flags & LK_TYPE_MASK) == 0) {
error = 0;
if ((flags & LK_INTERLOCK) == 0) if ((flags & LK_INTERLOCK) == 0)
VI_LOCK(vp); VI_LOCK(vp);
if ((flags & LK_NOWAIT || (flags & LK_TYPE_MASK) == 0) && if (vp->v_iflag & VI_DOOMED)
vp->v_iflag & VI_DOOMED) { error = ENOENT;
VI_UNLOCK(vp); VI_UNLOCK(vp);
return (ENOENT); return (error);
} }
/* do {
* Just polling to check validity. error = VOP_LOCK1(vp, flags, file, line);
*/ flags &= ~LK_INTERLOCK; /* Interlock is always dropped. */
if ((flags & LK_TYPE_MASK) == 0) {
VI_UNLOCK(vp);
return (0);
}
/*
* lockmgr drops interlock before it will return for
* any reason. So force the code above to relock it.
*/
error = VOP_LOCK1(vp, flags | LK_INTERLOCK, file, line);
flags &= ~LK_INTERLOCK;
KASSERT((flags & LK_RETRY) == 0 || error == 0, KASSERT((flags & LK_RETRY) == 0 || error == 0,
("LK_RETRY set with incompatible flags %d\n", flags)); ("LK_RETRY set with incompatible flags %d\n", flags));
/* /*