[CIFS] CIFS writepage improvements - eliminate double copy
Signed-off-by: Steve French (sfrench@us.ibm.com)
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 3c628bf..b4f7b98 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -951,56 +951,69 @@
}
#ifdef CONFIG_CIFS_EXPERIMENTAL
-int CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
+int
+CIFSSMBWrite2(const int xid, struct cifsTconInfo *tcon,
const int netfid, const unsigned int count,
- const __u64 offset, unsigned int *nbytes, const char __user *buf,
+ const __u64 offset, unsigned int *nbytes, const char *buf,
const int long_op)
{
int rc = -EACCES;
WRITE_REQ *pSMB = NULL;
- WRITE_RSP *pSMBr = NULL;
- /*int bytes_returned;*/
- unsigned bytes_sent;
+ int bytes_returned;
+ int smb_hdr_len;
+ __u32 bytes_sent;
__u16 byte_count;
+ cERROR(1,("write2 at %lld %d bytes",offset,count)); /* BB removeme BB */
rc = small_smb_init(SMB_COM_WRITE_ANDX, 14, tcon, (void **) &pSMB);
-
if (rc)
return rc;
-
- pSMBr = (WRITE_RSP *)pSMB; /* BB removeme BB */
-
/* tcon and ses pointer are checked in smb_init */
if (tcon->ses->server == NULL)
return -ECONNABORTED;
- pSMB->AndXCommand = 0xFF; /* none */
+ pSMB->AndXCommand = 0xFF; /* none */
pSMB->Fid = netfid;
pSMB->OffsetLow = cpu_to_le32(offset & 0xFFFFFFFF);
pSMB->OffsetHigh = cpu_to_le32(offset >> 32);
pSMB->Reserved = 0xFFFFFFFF;
pSMB->WriteMode = 0;
pSMB->Remaining = 0;
- bytes_sent = (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE) & ~0xFF;
+
+ /* Can increase buffer size if buffer is big enough in some cases - ie
+ can send more if LARGE_WRITE_X capability returned by the server and if
+ our buffer is big enough or if we convert to iovecs on socket writes
+ and eliminate the copy to the CIFS buffer */
+ if(tcon->ses->capabilities & CAP_LARGE_WRITE_X) {
+ bytes_sent = min_t(const unsigned int, CIFSMaxBufSize, count);
+ } else {
+ bytes_sent = (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE)
+ & ~0xFF;
+ }
+
if (bytes_sent > count)
bytes_sent = count;
- pSMB->DataLengthHigh = 0;
pSMB->DataOffset =
cpu_to_le16(offsetof(struct smb_com_write_req,Data) - 4);
- byte_count = bytes_sent + 1 /* pad */ ;
- pSMB->DataLengthLow = cpu_to_le16(bytes_sent);
- pSMB->DataLengthHigh = 0;
- pSMB->hdr.smb_buf_length += byte_count;
+ byte_count = bytes_sent + 1 /* pad */ ; /* BB fix this for sends > 64K */
+ pSMB->DataLengthLow = cpu_to_le16(bytes_sent & 0xFFFF);
+ pSMB->DataLengthHigh = cpu_to_le16(bytes_sent >> 16);
+ smb_hdr_len = pSMB->hdr.smb_buf_length + 1; /* hdr + 1 byte pad */
+ pSMB->hdr.smb_buf_length += bytes_sent+1;
pSMB->ByteCount = cpu_to_le16(byte_count);
-/* rc = SendReceive2(xid, tcon->ses, (struct smb_hdr *) pSMB,
- (struct smb_hdr *) pSMBr, buf, buflen, &bytes_returned, long_op); */ /* BB fixme BB */
+ rc = SendReceive2(xid, tcon->ses, (struct smb_hdr *) pSMB, smb_hdr_len,
+ buf, bytes_sent, &bytes_returned, long_op);
if (rc) {
- cFYI(1, ("Send error in write2 (large write) = %d", rc));
+ cFYI(1, ("Send error in write = %d", rc));
*nbytes = 0;
- } else
- *nbytes = le16_to_cpu(pSMBr->Count);
+ } else {
+ WRITE_RSP * pSMBr = (WRITE_RSP *)pSMB;
+ *nbytes = le16_to_cpu(pSMBr->CountHigh);
+ *nbytes = (*nbytes) << 16;
+ *nbytes += le16_to_cpu(pSMBr->Count);
+ }
cifs_small_buf_release(pSMB);
@@ -1009,6 +1022,8 @@
return rc;
}
+
+
#endif /* CIFS_EXPERIMENTAL */
int