From: Andreas Gruenbacher <[email protected]> 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 <[email protected]> Signed-off-by: Andreas Gruenbacher <[email protected]> Signed-off-by: Bob Peterson <[email protected]> --- fs/gfs2/glock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index f66773c71bcd..d32964cd1117 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); } -- 2.20.1
