Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.0 17/25] gfs2: Fix missed wakeups in find_insert_glock | Date | Tue, 12 Mar 2019 10:08:55 -0700 |
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5.0-stable review patch. If anyone has any objections, please let me know.
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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); }
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