CIFS: Separate SMB2 sync header processing

BugLink: http://bugs.launchpad.net/bugs/1670508
Do not process RFC1001 length in smb2_hdr_assemble() because
it is not a part of SMB2 header. This allows to cleanup the code
and adds a possibility combine several SMB2 packets into one
for compounding.

Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
(cherry picked from commit cb200bd6264a80c04e09e8635fa4f3901cabdaef)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 438c4b108c07471e1c9bfc871eab10a20438a6c8..f6ba2c03f7cce1b6a7ec0f855d3170dfd02a9d5b 100644 (file)
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -79,25 +79,9 @@ static const int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
 
 
 static void
-smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
+smb2_hdr_assemble(struct smb2_sync_hdr *shdr, __le16 smb2_cmd,
                  const struct cifs_tcon *tcon)
 {
-       struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
-       struct smb2_sync_hdr *shdr = get_sync_hdr(hdr);
-       char *temp = (char *)hdr;
-       /* lookup word count ie StructureSize from table */
-       __u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_cmd)];
-
-       /*
-        * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
-        * largest operations (Create)
-        */
-       memset(temp, 0, 256);
-
-       /* Note this is only network field converted to big endian */
-       hdr->smb2_buf_length =
-                       cpu_to_be32(parmsize + sizeof(struct smb2_sync_hdr));
-
        shdr->ProtocolId = SMB2_PROTO_NUMBER;
        shdr->StructureSize = cpu_to_le16(64);
        shdr->Command = smb2_cmd;
@@ -149,7 +133,6 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
        if (tcon->ses && tcon->ses->server && tcon->ses->server->sign)
                shdr->Flags |= SMB2_FLAGS_SIGNED;
 out:
-       pdu->StructureSize2 = cpu_to_le16(parmsize);
        return;
 }
 
@@ -290,6 +273,26 @@ out:
        return rc;
 }
 
+static void
+fill_small_buf(__le16 smb2_command, struct cifs_tcon *tcon, void *buf,
+              unsigned int *total_len)
+{
+       struct smb2_sync_pdu *spdu = (struct smb2_sync_pdu *)buf;
+       /* lookup word count ie StructureSize from table */
+       __u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_command)];
+
+       /*
+        * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
+        * largest operations (Create)
+        */
+       memset(buf, 0, 256);
+
+       smb2_hdr_assemble(&spdu->sync_hdr, smb2_command, tcon);
+       spdu->StructureSize2 = cpu_to_le16(parmsize);
+
+       *total_len = parmsize + sizeof(struct smb2_sync_hdr);
+}
+
 /*
  * Allocate and return pointer to an SMB request hdr, and set basic
  * SMB information in the SMB header. If the return code is zero, this
@@ -299,7 +302,9 @@ static int
 small_smb2_init(__le16 smb2_command, struct cifs_tcon *tcon,
                void **request_buf)
 {
-       int rc = 0;
+       int rc;
+       unsigned int total_len;
+       struct smb2_pdu *pdu;
 
        rc = smb2_reconnect(smb2_command, tcon);
        if (rc)
@@ -312,7 +317,12 @@ small_smb2_init(__le16 smb2_command, struct cifs_tcon *tcon,
                return -ENOMEM;
        }
 
-       smb2_hdr_assemble((struct smb2_hdr *) *request_buf, smb2_command, tcon);
+       pdu = (struct smb2_pdu *)(*request_buf);
+
+       fill_small_buf(smb2_command, tcon, get_sync_hdr(pdu), &total_len);
+
+       /* Note this is only network field converted to big endian */
+       pdu->hdr.smb2_buf_length = cpu_to_be32(total_len);
 
        if (tcon != NULL) {
 #ifdef CONFIG_CIFS_STATS2

diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 8dd24b73d974068dc3982ea5f553bc0a05448e93..052342da484484dc4b87ba513340ef23bd02eb51 100644 (file)
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -117,6 +117,11 @@ struct smb2_sync_hdr {
        __u8   Signature[16];
 } __packed;
 
+struct smb2_sync_pdu {
+       struct smb2_sync_hdr sync_hdr;
+       __le16 StructureSize2; /* size of wct area (varies, request specific) */
+} __packed;
+
 struct smb2_hdr {
        __be32 smb2_buf_length; /* big endian on wire */
                                /* length is only two or three bytes - with */