net/9p: handle flushed Tclunk/Tremove

When a Tclunk or Tremove request is flushed, the fid is not freed on the
server.

p9_client_clunk() should retry once on interrupt, then if interrupted
again, leak the fid for the duration of the connection.

p9_client_remove() should call p9_client_clunk() on interrupt
instead of unconditionally destroying the fid.

Signed-off-by: Jim Garlick <garlick@llnl.gov>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/client.c b/net/9p/client.c
index 6efbb33..b23a17c 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1428,6 +1428,7 @@ int p9_client_clunk(struct p9_fid *fid)
        int err;
        struct p9_client *clnt;
        struct p9_req_t *req;
+       int retries = 0;
 
        if (!fid) {
                pr_warn("%s (%d): Trying to clunk with NULL fid\n",
@@ -1436,7 +1437,9 @@ int p9_client_clunk(struct p9_fid *fid)
                return 0;
        }
 
-       p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d\n", fid->fid);
+again:
+       p9_debug(P9_DEBUG_9P, ">>> TCLUNK fid %d (try %d)\n", fid->fid,
+                                                               retries);
        err = 0;
        clnt = fid->clnt;
 
@@ -1452,8 +1455,14 @@ int p9_client_clunk(struct p9_fid *fid)
 error:
        /*
         * Fid is not valid even after a failed clunk
+        * If interrupted, retry once then give up and
+        * leak fid until umount.
         */
-       p9_fid_destroy(fid);
+       if (err == -ERESTARTSYS) {
+               if (retries++ == 0)
+                       goto again;
+       } else
+               p9_fid_destroy(fid);
        return err;
 }
 EXPORT_SYMBOL(p9_client_clunk);
@@ -1478,7 +1487,10 @@ int p9_client_remove(struct p9_fid *fid)
 
        p9_free_req(clnt, req);
 error:
-       p9_fid_destroy(fid);
+       if (err == -ERESTARTSYS)
+               p9_client_clunk(fid);
+       else
+               p9_fid_destroy(fid);
        return err;
 }
 EXPORT_SYMBOL(p9_client_remove);