From: Andreas Gruenbacher Date: Wed, 6 Mar 2019 14:41:57 +0000 (+0100) Subject: gfs2: Fix missed wakeups in find_insert_glock X-Git-Tag: rel_imx_4.19.35_1.1.0~5965 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=4f5a4c8881064c2eac658528390a6f2e7253c9b5;p=linux.git gfs2: Fix missed wakeups in find_insert_glock 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 Signed-off-by: Andreas Gruenbacher Signed-off-by: Bob Peterson Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 4614ee25f621..9d566e62684c 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -107,7 +107,7 @@ static int glock_wake_function(wait_queue_entry_t *wait, unsigned int mode, 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); }