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 <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfs/pnfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
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);
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
