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

To avoid a deadlock when handling .. directory during a lookup, we unlock

Browse Source 
parent vnode and relock it after locking child vnode. The problem was that
we always relock it exclusively, even when it was share-locked.

Discussed with:	jeff
This commit is contained in:
Pawel Jakub Dawidek 2007-05-25 22:23:38 +00:00
parent b4c85af977
commit 6e042171bd
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=170000
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
sys/kern/vfs_cache.c
View File

@ -315,7 +315,7 @@ cache_lookup(dvp, vpp, cnp)
{
struct namecache *ncp;
u_int32_t hash;
int error;
int error, ltype;
if (!doingcache) {
cnp->cn_flags &= ~MAKEENTRY;
@ -421,13 +421,16 @@ cache_lookup(dvp, vpp, cnp)
CACHE_UNLOCK();
return (-1);
}
if (cnp->cn_flags & ISDOTDOT)
ltype = 0; /* silence gcc warning */
if (cnp->cn_flags & ISDOTDOT) {
ltype = VOP_ISLOCKED(dvp, cnp->cn_thread);
VOP_UNLOCK(dvp, 0, cnp->cn_thread);
}
VI_LOCK(*vpp);
CACHE_UNLOCK();
error = vget(*vpp, cnp->cn_lkflags | LK_INTERLOCK, cnp->cn_thread);
if (cnp->cn_flags & ISDOTDOT)
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, cnp->cn_thread);
vn_lock(dvp, ltype | LK_RETRY, cnp->cn_thread);
if (error) {
*vpp = NULL;
goto retry;