[CIFS] Add support for legacy servers part 5

Handle small negotiated read sizes (under 4K) and finish up
read and write support.

Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 20 insertions, 79 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 74733851cfad..b8830118f09a 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -923,81 +923,6 @@ openRetry:
         return rc;
 }
 
-int
-SMBLegacyRead(const int xid, struct cifsTconInfo *tcon,
-            const int netfid, unsigned int count,
-            const __u64 lseek, unsigned int *nbytes, char **buf)
-{
-        int rc = -EACCES;
-        READX_REQ *pSMB = NULL;
-        READ_RSP *pSMBr = NULL;
-        char *pReadData = NULL;
-        int bytes_returned;
-
-        cFYI(1,("Legacy read %d bytes fid %d",count,netfid));
-
-        /* field is shorter in legacy read, only 16 bits */
-        if(count > 2048)
-                count = 2048;  /* BB FIXME make this configurable */
-
-        if(lseek > 0xFFFFFFFF)
-                return -EIO; /* can not read that far into file on old server */
-
-        *nbytes = 0;
-        rc = smb_init(SMB_COM_READ_ANDX, 10, tcon, (void **) &pSMB,
-                      (void **) &pSMBr);
-        if (rc)
-                return rc;
-
-        /* tcon and ses pointer are checked in smb_init */
-        if (tcon->ses->server == NULL)
-                return -ECONNABORTED;
-
-        pSMB->AndXCommand = 0xFF;       /* none */
-        pSMB->Fid = netfid;
-        pSMB->OffsetLow = cpu_to_le32(lseek & 0xFFFFFFFF);
-        pSMB->Remaining = 0;
-        pSMB->MaxCount = cpu_to_le16(count);
-        pSMB->Reserved = 0; /* Must Be Zero */
-        pSMB->ByteCount = 0;  /* no need to do le conversion since it is 0 */
-
-        rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
-                         (struct smb_hdr *) pSMBr, &bytes_returned, 0);
-        cifs_stats_inc(&tcon->num_reads);
-        if (rc) {
-                cERROR(1, ("Send error in legacy read = %d", rc));
-        } else {
-                int data_length = le16_to_cpu(pSMBr->DataLengthHigh);
-                data_length = data_length << 16;
-                data_length += le16_to_cpu(pSMBr->DataLength);
-                *nbytes = data_length;
-
-                /*check that DataLength would not go beyond end of SMB */
-                if ((data_length > CIFSMaxBufSize) || (data_length > count)) {
-                        cFYI(1,("bad length %d for count %d",data_length,count));
-                        rc = -EIO;
-                        *nbytes = 0;
-                } else {
-                        pReadData = (char *) (&pSMBr->hdr.Protocol) +
-                                                le16_to_cpu(pSMBr->DataOffset);
-/*                      if(rc = copy_to_user(buf, pReadData, data_length)) {
-                                cERROR(1,("Faulting on read rc = %d",rc));
-                                rc = -EFAULT;
-                        }*/ /* can not use copy_to_user when using page cache*/
-                        if(*buf)
-                                memcpy(*buf,pReadData,data_length);
-                }
-        }
-        if(*buf)
-                cifs_buf_release(pSMB);
-        else
-                *buf = (char *)pSMB;
-
-        /* Note: On -EAGAIN error only caller can retry on handle based calls
-                since file handle passed in no longer valid */
-        return rc;
-}
-
 /* If no buffer passed in, then caller wants to do the copy
         as in the case of readpages so the SMB buffer must be
         freed by the caller */
@@ -1012,11 +937,16 @@ CIFSSMBRead(const int xid, struct cifsTconInfo *tcon,
         READ_RSP *pSMBr = NULL;
         char *pReadData = NULL;
         int bytes_returned;
+        int wct;
 
         cFYI(1,("Reading %d bytes on fid %d",count,netfid));
+        if(tcon->ses->capabilities & CAP_LARGE_FILES)
+                wct = 12;
+        else
+                wct = 10; /* old style read */
 
         *nbytes = 0;
-        rc = smb_init(SMB_COM_READ_ANDX, 12, tcon, (void **) &pSMB,
+        rc = smb_init(SMB_COM_READ_ANDX, wct, tcon, (void **) &pSMB,
                       (void **) &pSMBr);
         if (rc)
                 return rc;
@@ -1028,12 +958,23 @@ CIFSSMBRead(const int xid, struct cifsTconInfo *tcon,
         pSMB->AndXCommand = 0xFF;       /* none */
         pSMB->Fid = netfid;
         pSMB->OffsetLow = cpu_to_le32(lseek & 0xFFFFFFFF);
-        pSMB->OffsetHigh = cpu_to_le32(lseek >> 32);
+        if(wct == 12)
+                pSMB->OffsetHigh = cpu_to_le32(lseek >> 32);
+        else if((lseek >> 32) > 0) /* can not handle this big offset for old */
+                return -EIO;
+
         pSMB->Remaining = 0;
         pSMB->MaxCount = cpu_to_le16(count & 0xFFFF);
         pSMB->MaxCountHigh = cpu_to_le32(count >> 16);
-        pSMB->ByteCount = 0;  /* no need to do le conversion since it is 0 */
-
+        if(wct == 12)
+                pSMB->ByteCount = 0;  /* no need to do le conversion since 0 */
+        else {
+                /* old style read */
+                struct smb_com_readx_req * pSMBW = 
+                        (struct smb_com_readx_req *)pSMB;
+                pSMBW->ByteCount = 0;   
+        }
+        
         rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
                          (struct smb_hdr *) pSMBr, &bytes_returned, 0);
         cifs_stats_inc(&tcon->num_reads);