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>

1 files changed, 55 insertions, 37 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 50b3523912ff..217d36587185 100644
--- 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);