svn commit: r195783 - stable/7/sys/ufs/ufs
Sean Nicholas Barkas
snb at FreeBSD.org
Mon Jul 20 16:19:43 UTC 2009
Author: snb
Date: Mon Jul 20 16:19:42 2009
New Revision: 195783
URL: http://svn.freebsd.org/changeset/base/195783
Log:
MFC r195003:
Fix a bug reported by pho@ where one can induce a panic by decreasing
vfs.ufs.dirhash_maxmem below the current amount of memory used by dirhash. When
ufsdirhash_build() is called with the memory in use greater than dirhash_maxmem,
it attempts to free up memory by calling ufsdirhash_recycle(). If successful in
freeing enough memory, ufsdirhash_recycle() leaves the dirhash list locked. But
at this point in ufsdirhash_build(), the list is not explicitly unlocked after
the call(s) to ufsdirhash_recycle(). When we next attempt to lock the dirhash
list, we will get a "panic: _mtx_lock_sleep: recursed on non-recursive mutex
dirhash list".
Approved by: dwmalone (mentor)
Modified:
stable/7/sys/ufs/ufs/ufs_dirhash.c
Modified: stable/7/sys/ufs/ufs/ufs_dirhash.c
==============================================================================
--- stable/7/sys/ufs/ufs/ufs_dirhash.c Mon Jul 20 13:55:33 2009 (r195782)
+++ stable/7/sys/ufs/ufs/ufs_dirhash.c Mon Jul 20 16:19:42 2009 (r195783)
@@ -329,9 +329,12 @@ ufsdirhash_build(struct inode *ip)
int dirblocks, i, j, memreqd, nblocks, narrays, nslots, slot;
/* Take care of a decreased sysctl value. */
- while (ufs_dirhashmem > ufs_dirhashmaxmem)
+ while (ufs_dirhashmem > ufs_dirhashmaxmem) {
if (ufsdirhash_recycle(0) != 0)
return (-1);
+ /* Recycled enough memory, so unlock the list. */
+ DIRHASHLIST_UNLOCK();
+ }
/* Check if we can/should use dirhash. */
if (ip->i_size < ufs_mindirhashsize || OFSFMT(ip->i_vnode) ||
More information about the svn-src-stable-7
mailing list