From f49f9baac8f63de9cbc17a0a84e04060496e8e76 Mon Sep 17 00:00:00 2001 From: Fred Isaman Date: Thu, 3 Feb 2011 18:28:52 +0000 Subject: pnfs: fix pnfs lock inversion of i_lock and cl_lock The pnfs code was using throughout the lock order i_lock, cl_lock. This conflicts with the nfs delegation code. Rework the pnfs code to avoid taking both locks simultaneously. Currently the code takes the double lock to add/remove the layout to a nfs_client list, while atomically checking that the list of lsegs is empty. To avoid this, we rely on existing serializations. When a layout is initialized with lseg count equal zero, LAYOUTGET's openstateid serialization is in effect, making it safe to assume it stays zero unless we change it. And once a layout's lseg count drops to zero, it is set as DESTROYED and so will stay at zero. Signed-off-by: Fred Isaman Signed-off-by: Trond Myklebust --- fs/nfs/callback_proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/nfs/callback_proc.c') diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index 89587573fe50..2f41dccea18e 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -188,10 +188,10 @@ static u32 initiate_bulk_draining(struct nfs_client *clp, rv = NFS4ERR_DELAY; list_del_init(&lo->plh_bulk_recall); spin_unlock(&ino->i_lock); + pnfs_free_lseg_list(&free_me_list); put_layout_hdr(lo); iput(ino); } - pnfs_free_lseg_list(&free_me_list); return rv; } -- cgit v1.2.3