CIFS: Move buffer allocation to a separate function

Reviewed-and-Tested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 50b3523912ff3c3fc2cf09f4f771a1a86e214e82..217d3658718574cf1fed3ecaa36c72436a768545 100644 (file)
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -319,15 +319,53 @@ requeue_echo:
        queue_delayed_work(system_nrt_wq, &server->echo, SMB_ECHO_INTERVAL);
 }
 
+static bool
+allocate_buffers(char **bigbuf, char **smallbuf, unsigned int size,
+                bool is_large_buf)
+{
+       char *bbuf = *bigbuf, *sbuf = *smallbuf;
+
+       if (bbuf == NULL) {
+               bbuf = (char *)cifs_buf_get();
+               if (!bbuf) {
+                       cERROR(1, "No memory for large SMB response");
+                       msleep(3000);
+                       /* retry will check if exiting */
+                       return false;
+               }
+       } else if (is_large_buf) {
+               /* we are reusing a dirty large buf, clear its start */
+               memset(bbuf, 0, size);
+       }
+
+       if (sbuf == NULL) {
+               sbuf = (char *)cifs_small_buf_get();
+               if (!sbuf) {
+                       cERROR(1, "No memory for SMB response");
+                       msleep(1000);
+                       /* retry will check if exiting */
+                       return false;
+               }
+               /* beginning of smb buffer is cleared in our buf_get */
+       } else {
+               /* if existing small buf clear beginning */
+               memset(sbuf, 0, size);
+       }
+
+       *bigbuf = bbuf;
+       *smallbuf = sbuf;
+
+       return true;
+}
+
 static int
 cifs_demultiplex_thread(void *p)
 {
        int length;
        struct TCP_Server_Info *server = p;
        unsigned int pdu_length, total_read;
+       char *buf = NULL, *bigbuf = NULL, *smallbuf = NULL;
        struct smb_hdr *smb_buffer = NULL;
-       struct smb_hdr *bigbuf = NULL;
-       struct smb_hdr *smallbuf = NULL;
        struct msghdr smb_msg;
        struct kvec iov;
        struct socket *csocket = server->ssocket;
@@ -351,35 +389,16 @@ cifs_demultiplex_thread(void *p)
        while (server->tcpStatus != CifsExiting) {
                if (try_to_freeze())
                        continue;
-               if (bigbuf == NULL) {
-                       bigbuf = cifs_buf_get();
-                       if (!bigbuf) {
-                               cERROR(1, "No memory for large SMB response");
-                               msleep(3000);
-                               /* retry will check if exiting */
-                               continue;
-                       }
-               } else if (isLargeBuf) {
-                       /* we are reusing a dirty large buf, clear its start */
-                       memset(bigbuf, 0, sizeof(struct smb_hdr));
-               }
 
-               if (smallbuf == NULL) {
-                       smallbuf = cifs_small_buf_get();
-                       if (!smallbuf) {
-                               cERROR(1, "No memory for SMB response");
-                               msleep(1000);
-                               /* retry will check if exiting */
-                               continue;
-                       }
-                       /* beginning of smb buffer is cleared in our buf_get */
-               } else /* if existing small buf clear beginning */
-                       memset(smallbuf, 0, sizeof(struct smb_hdr));
+               if (!allocate_buffers(&bigbuf, &smallbuf,
+                                     sizeof(struct smb_hdr), isLargeBuf))
+                       continue;
 
                isLargeBuf = false;
                isMultiRsp = false;
-               smb_buffer = smallbuf;
-               iov.iov_base = smb_buffer;
+               smb_buffer = (struct smb_hdr *)smallbuf;
+               buf = smallbuf;
+               iov.iov_base = buf;
                iov.iov_len = 4;
                smb_msg.msg_control = NULL;
                smb_msg.msg_controllen = 0;
@@ -417,8 +436,7 @@ incomplete_rcv:
                                allowing socket to clear and app threads to set
                                tcpStatus CifsNeedReconnect if server hung */
                        if (pdu_length < 4) {
-                               iov.iov_base = (4 - pdu_length) +
-                                                       (char *)smb_buffer;
+                               iov.iov_base = (4 - pdu_length) + buf;
                                iov.iov_len = pdu_length;
                                smb_msg.msg_control = NULL;
                                smb_msg.msg_controllen = 0;
@@ -446,7 +464,7 @@ incomplete_rcv:
                /* the first byte big endian of the length field,
                is actually not part of the length but the type
                with the most common, zero, as regular data */
-               temp = *((char *) smb_buffer);
+               temp = *buf;
 
                /* Note that FC 1001 length is big endian on the wire,
                but we convert it here so it is always manipulated
@@ -480,8 +498,7 @@ incomplete_rcv:
                        continue;
                } else if (temp != (char) 0) {
                        cERROR(1, "Unknown RFC 1002 frame");
-                       cifs_dump_mem(" Received Data: ", (char *)smb_buffer,
-                                     length);
+                       cifs_dump_mem(" Received Data: ", buf, length);
                        cifs_reconnect(server);
                        csocket = server->ssocket;
                        continue;
@@ -504,10 +521,11 @@ incomplete_rcv:
                if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
                        isLargeBuf = true;
                        memcpy(bigbuf, smallbuf, 4);
-                       smb_buffer = bigbuf;
+                       smb_buffer = (struct smb_hdr *)bigbuf;
+                       buf = bigbuf;
                }
                length = 0;
-               iov.iov_base = 4 + (char *)smb_buffer;
+               iov.iov_base = 4 + buf;
                iov.iov_len = pdu_length;
                for (total_read = 0; total_read < pdu_length;
                     total_read += length) {
@@ -562,8 +580,8 @@ incomplete_rcv:
                 */
                length = checkSMB(smb_buffer, smb_buffer->Mid, total_read);
                if (length != 0)
-                       cifs_dump_mem("Bad SMB: ", smb_buffer,
-                                       min_t(unsigned int, total_read, 48));
+                       cifs_dump_mem("Bad SMB: ", buf,
+                                     min_t(unsigned int, total_read, 48));
 
                mid_entry = NULL;
                server->lstrp = jiffies;
@@ -648,7 +666,7 @@ multi_t2_fnd:
                           !isMultiRsp) {
                        cERROR(1, "No task to wake, unknown frame received! "
                                   "NumMids %d", atomic_read(&midCount));
-                       cifs_dump_mem("Received Data is: ", (char *)smb_buffer,
+                       cifs_dump_mem("Received Data is: ", buf,
                                      sizeof(struct smb_hdr));
 #ifdef CONFIG_CIFS_DEBUG2
                        cifs_dump_detail(smb_buffer);