CIFS: Use multicredits for SMB 2.1/3 reads

[cascardo/linux.git] / fs / cifs / smb2pdu.c

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index be7b2eb..c31e5a0 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1747,11 +1747,12 @@ smb2_readv_callback(struct mid_q_entry *mid)
 int
 smb2_async_readv(struct cifs_readdata *rdata)
 {
-       int rc;
+       int rc, flags = 0;
        struct smb2_hdr *buf;
        struct cifs_io_parms io_parms;
        struct smb_rqst rqst = { .rq_iov = &rdata->iov,
                                 .rq_nvec = 1 };
+       struct TCP_Server_Info *server;
 
        cifs_dbg(FYI, "%s: offset=%llu bytes=%u\n",
                 __func__, rdata->offset, rdata->bytes);
@@ -1762,18 +1763,41 @@ smb2_async_readv(struct cifs_readdata *rdata)
        io_parms.persistent_fid = rdata->cfile->fid.persistent_fid;
        io_parms.volatile_fid = rdata->cfile->fid.volatile_fid;
        io_parms.pid = rdata->pid;
+
+       server = io_parms.tcon->ses->server;
+
        rc = smb2_new_read_req(&rdata->iov, &io_parms, 0, 0);
-       if (rc)
+       if (rc) {
+               if (rc == -EAGAIN && rdata->credits) {
+                       /* credits was reset by reconnect */
+                       rdata->credits = 0;
+                       /* reduce in_flight value since we won't send the req */
+                       spin_lock(&server->req_lock);
+                       server->in_flight--;
+                       spin_unlock(&server->req_lock);
+               }
                return rc;
+       }
 
        buf = (struct smb2_hdr *)rdata->iov.iov_base;
        /* 4 for rfc1002 length field */
        rdata->iov.iov_len = get_rfc1002_length(rdata->iov.iov_base) + 4;
 
+       if (rdata->credits) {
+               buf->CreditCharge = cpu_to_le16(DIV_ROUND_UP(rdata->bytes,
+                                               SMB2_MAX_BUFFER_SIZE));
+               spin_lock(&server->req_lock);
+               server->credits += rdata->credits -
+                                               le16_to_cpu(buf->CreditCharge);
+               spin_unlock(&server->req_lock);
+               wake_up(&server->request_q);
+               flags = CIFS_HAS_CREDITS;
+       }
+
        kref_get(&rdata->refcount);
        rc = cifs_call_async(io_parms.tcon->ses->server, &rqst,
                             cifs_readv_receive, smb2_readv_callback,
-                            rdata, 0);
+                            rdata, flags);
        if (rc) {
                kref_put(&rdata->refcount, cifs_readdata_release);
                cifs_stats_fail_inc(io_parms.tcon, SMB2_READ_HE);