diff options
| -rw-r--r-- | fs/cifs/transport.c | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 2045f886546c..9c3a6809194c 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -860,13 +860,41 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, if (ses->server->tcpStatus == CifsExiting) return -ENOENT; + spin_lock(&ses->server->req_lock); + if (ses->server->credits < num_rqst) { + /* + * Return immediately if not too many requests in flight since + * we will likely be stuck on waiting for credits. + */ + if (ses->server->in_flight < num_rqst - ses->server->credits) { + spin_unlock(&ses->server->req_lock); + return -ENOTSUPP; + } + } else { + /* enough credits to send the whole compounded request */ + ses->server->credits -= num_rqst; + ses->server->in_flight += num_rqst; + first_instance = ses->server->reconnect_instance; + } + spin_unlock(&ses->server->req_lock); + + if (first_instance) { + cifs_dbg(FYI, "Acquired %d credits at once\n", num_rqst); + for (i = 0; i < num_rqst; i++) { + credits[i].value = 1; + credits[i].instance = first_instance; + } + goto setup_rqsts; + } + /* + * There are not enough credits to send the whole compound request but + * there are requests in flight that may bring credits from the server. + * This approach still leaves the possibility to be stuck waiting for + * credits if the server doesn't grant credits to the outstanding + * requests. This should be fixed by returning immediately and letting + * a caller fallback to sequential commands instead of compounding. * Ensure we obtain 1 credit per request in the compound chain. - * It can be optimized further by waiting for all the credits - * at once but this can wait long enough if we don't have enough - * credits due to some heavy operations in progress or the server - * not granting us much, so a fallback to the current approach is - * needed anyway. */ for (i = 0; i < num_rqst; i++) { rc = wait_for_free_request(ses->server, timeout, optype, @@ -906,6 +934,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, } } +setup_rqsts: /* * Make sure that we sign in the same order that we send on this socket * and avoid races inside tcp sendmsg code that could cause corruption |