| From 605b0487f0bc1ae9963bf52ece0f5c8055186f81 Mon Sep 17 00:00:00 2001 |
| From: Andreas Gruenbacher <agruenba@redhat.com> |
| Date: Wed, 6 Mar 2019 15:41:57 +0100 |
| Subject: gfs2: Fix missed wakeups in find_insert_glock |
| |
| From: Andreas Gruenbacher <agruenba@redhat.com> |
| |
| commit 605b0487f0bc1ae9963bf52ece0f5c8055186f81 upstream. |
| |
| Mark Syms has reported seeing tasks that are stuck waiting in |
| find_insert_glock. It turns out that struct lm_lockname contains four padding |
| bytes on 64-bit architectures that function glock_waitqueue doesn't skip when |
| hashing the glock name. As a result, we can end up waking up the wrong |
| waitqueue, and the waiting tasks may be stuck forever. |
| |
| Fix that by using ht_parms.key_len instead of sizeof(struct lm_lockname) for |
| the key length. |
| |
| Reported-by: Mark Syms <mark.syms@citrix.com> |
| Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> |
| Signed-off-by: Bob Peterson <rpeterso@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/gfs2/glock.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/fs/gfs2/glock.c |
| +++ b/fs/gfs2/glock.c |
| @@ -107,7 +107,7 @@ static int glock_wake_function(wait_queu |
| |
| static wait_queue_head_t *glock_waitqueue(struct lm_lockname *name) |
| { |
| - u32 hash = jhash2((u32 *)name, sizeof(*name) / 4, 0); |
| + u32 hash = jhash2((u32 *)name, ht_parms.key_len / 4, 0); |
| |
| return glock_wait_table + hash_32(hash, GLOCK_WAIT_TABLE_BITS); |
| } |
