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| author | snb <snb@FreeBSD.org> | 2009-06-25 20:40:13 +0000 |
|---|---|---|
| committer | snb <snb@FreeBSD.org> | 2009-06-25 20:40:13 +0000 |
| commit | 5d2850ae03b3aae3b966028ceb9b1b04c7093197 (patch) | |
| tree | 4037e45800143a968f40328f85b61e9f3daa55bd /sys/ufs | |
| parent | 6d5618d67ce9b5926b533d242ff4e234e0f2a680 (diff) | |
| download | FreeBSD-src-5d2850ae03b3aae3b966028ceb9b1b04c7093197.zip FreeBSD-src-5d2850ae03b3aae3b966028ceb9b1b04c7093197.tar.gz | |
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".
Tested by: pho
Approved by: dwmalone (mentor)
MFC after: 3 weeks
Diffstat (limited to 'sys/ufs')
| -rw-r--r-- | sys/ufs/ufs/ufs_dirhash.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/sys/ufs/ufs/ufs_dirhash.c b/sys/ufs/ufs/ufs_dirhash.c index 7f801af..e18b838 100644 --- a/sys/ufs/ufs/ufs_dirhash.c +++ b/sys/ufs/ufs/ufs_dirhash.c @@ -348,9 +348,12 @@ 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) || |
