From: Trond Myklebust Date: Sun, 4 Sep 2016 16:46:35 +0000 (-0400) Subject: pNFS: Don't forget the layout stateid if there are outstanding LAYOUTGETs X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=334a8f37115bf35e38617315a360a91ac4f2b2c6;p=deliverable%2Flinux.git pNFS: Don't forget the layout stateid if there are outstanding LAYOUTGETs If there are outstanding LAYOUTGET rpc calls, then we want to ensure that we keep the layout stateid around so we that don't inadvertently pick up an old/misordered sequence id. The race is as follows: Client Server ====== ====== LAYOUTGET(seqid) LAYOUTGET(seqid) return LAYOUTGET(seqid+1) return LAYOUTGET(seqid+2) process LAYOUTGET(seqid+2) forget layout process LAYOUTGET(seqid+1) If it forgets the layout stateid before processing seqid+1, then the client will not check the layout->plh_barrier, and so will set the stateid with seqid+1. Signed-off-by: Trond Myklebust --- diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index cd8b5fca33f6..2c93a85eda51 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -365,7 +365,8 @@ pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo, /* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */ atomic_dec(&lo->plh_refcount); if (list_empty(&lo->plh_segs)) { - set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags); + if (atomic_read(&lo->plh_outstanding) == 0) + set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags); clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags); } rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);