[CIFS] Add support for legacy servers part nine. statfs (df and du) is now

functional, and the length check is fixed so readdir does not throw a
warning message when windows me messes up the response to FindFirst
of an empty dir (with only . and ..).

Signed-off-by: Steve French (sfrench@us.ibm.com)

7 files changed, 107 insertions, 10 deletions

diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 47ae68b51847..661b45906d09 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -3,7 +3,8 @@ Version 1.37
 Fix readdir caching when unlink removes file in current search buffer,
 and this is followed by a rewind search to just before the deleted entry.
 Do not attempt to set ctime unless atime and/or mtime change requested
-(most servers throw it away anyway).
+(most servers throw it away anyway). Fix length check of received smbs
+to be more accurate.
 
 Version 1.36
 ------------
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index f738c8b19e3b..1f97d39100ee 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -205,6 +205,10 @@ cifs_statfs(struct super_block *sb, struct kstatfs *buf)
 #endif /* CIFS_EXPERIMENTAL */
         rc = CIFSSMBQFSInfo(xid, pTcon, buf);
 
+        /* Old Windows servers do not support level 103, retry with level 
+           one if old server failed the previous call */ 
+        if(rc)
+                rc = SMBOldQFSInfo(xid, pTcon, buf);
         /*     
            int f_type;
            __fsid_t f_fsid;
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index cf466595b0d4..3fa37790bea2 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -1684,6 +1684,14 @@ typedef struct {
 } FILE_SYSTEM_INFO;             /* size info, level 0x103 */
 
 typedef struct {
+        __le32 fsid;
+        __le32 SectorsPerAllocationUnit;
+        __le32 TotalAllocationUnits;
+        __le32 FreeAllocationUnits;
+        __le16  BytesPerSector;
+} FILE_SYSTEM_ALLOC_INFO;
+
+typedef struct {
         __le16 MajorVersionNumber;
         __le16 MinorVersionNumber;
         __le64 Capability;
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 6943f7c6de08..0bace385e97a 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -133,6 +133,8 @@ extern int get_dfs_path(int xid, struct cifsSesInfo *pSesInfo,
                         int remap);
 extern int CIFSSMBQFSInfo(const int xid, struct cifsTconInfo *tcon,
                         struct kstatfs *FSData);
+extern int SMBOldQFSInfo(const int xid, struct cifsTconInfo *tcon,
+                        struct kstatfs *FSData);
 extern int CIFSSMBSetFSUnixInfo(const int xid, struct cifsTconInfo *tcon,
                         __u64 cap);
 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index f72a61df3c68..daf717e6b6eb 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -3215,6 +3215,92 @@ GetDFSRefExit:
         return rc;
 }
 
+/* Query File System Info such as free space to old servers such as Win 9x */
+int
+SMBOldQFSInfo(const int xid, struct cifsTconInfo *tcon, struct kstatfs *FSData)
+{
+/* level 0x01 SMB_QUERY_FILE_SYSTEM_INFO */
+        TRANSACTION2_QFSI_REQ *pSMB = NULL;
+        TRANSACTION2_QFSI_RSP *pSMBr = NULL;
+        FILE_SYSTEM_ALLOC_INFO *response_data;
+        int rc = 0;
+        int bytes_returned = 0;
+        __u16 params, byte_count;
+
+        cFYI(1, ("OldQFSInfo"));
+oldQFSInfoRetry:
+        rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB,
+                (void **) &pSMBr);
+        if (rc)
+                return rc;
+        rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB,
+                      (void **) &pSMBr);
+        if (rc)
+                return rc;
+
+        params = 2;     /* level */
+        pSMB->TotalDataCount = 0;
+        pSMB->MaxParameterCount = cpu_to_le16(2);
+        pSMB->MaxDataCount = cpu_to_le16(1000);
+        pSMB->MaxSetupCount = 0;
+        pSMB->Reserved = 0;
+        pSMB->Flags = 0;
+        pSMB->Timeout = 0;
+        pSMB->Reserved2 = 0;
+        byte_count = params + 1 /* pad */ ;
+        pSMB->TotalParameterCount = cpu_to_le16(params);
+        pSMB->ParameterCount = pSMB->TotalParameterCount;
+        pSMB->ParameterOffset = cpu_to_le16(offsetof(
+        struct smb_com_transaction2_qfsi_req, InformationLevel) - 4);
+        pSMB->DataCount = 0;
+        pSMB->DataOffset = 0;
+        pSMB->SetupCount = 1;
+        pSMB->Reserved3 = 0;
+        pSMB->SubCommand = cpu_to_le16(TRANS2_QUERY_FS_INFORMATION);
+        pSMB->InformationLevel = cpu_to_le16(SMB_INFO_ALLOCATION);
+        pSMB->hdr.smb_buf_length += byte_count;
+        pSMB->ByteCount = cpu_to_le16(byte_count);
+
+        rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
+                (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+        if (rc) {
+                cFYI(1, ("Send error in QFSInfo = %d", rc));
+        } else {                /* decode response */
+                rc = validate_t2((struct smb_t2_rsp *)pSMBr);
+
+                if (rc || (pSMBr->ByteCount < 18))
+                        rc = -EIO;      /* bad smb */
+                else {
+                        __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
+                        cFYI(1,("qfsinf resp BCC: %d  Offset %d",
+                                 pSMBr->ByteCount, data_offset));
+
+                        response_data =
+                                (FILE_SYSTEM_ALLOC_INFO *) 
+                                (((char *) &pSMBr->hdr.Protocol) + data_offset);
+                        FSData->f_bsize =
+                                le16_to_cpu(response_data->BytesPerSector) *
+                                le32_to_cpu(response_data->
+                                        SectorsPerAllocationUnit);
+                        FSData->f_blocks =
+                                le32_to_cpu(response_data->TotalAllocationUnits);
+                        FSData->f_bfree = FSData->f_bavail =
+                                le32_to_cpu(response_data->FreeAllocationUnits);
+                        cFYI(1,
+                             ("Blocks: %lld  Free: %lld Block size %ld",
+                              (unsigned long long)FSData->f_blocks,
+                              (unsigned long long)FSData->f_bfree,
+                              FSData->f_bsize));
+                }
+        }
+        cifs_buf_release(pSMB);
+
+        if (rc == -EAGAIN)
+                goto oldQFSInfoRetry;
+
+        return rc;
+}
+
 int
 CIFSSMBQFSInfo(const int xid, struct cifsTconInfo *tcon, struct kstatfs *FSData)
 {
@@ -3236,7 +3322,7 @@ QFSInfoRetry:
         params = 2;     /* level */
         pSMB->TotalDataCount = 0;
         pSMB->MaxParameterCount = cpu_to_le16(2);
-        pSMB->MaxDataCount = cpu_to_le16(1000); /* BB find exact max SMB PDU from sess structure BB */
+        pSMB->MaxDataCount = cpu_to_le16(1000);
         pSMB->MaxSetupCount = 0;
         pSMB->Reserved = 0;
         pSMB->Flags = 0;
@@ -3259,17 +3345,14 @@ QFSInfoRetry:
         rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
                          (struct smb_hdr *) pSMBr, &bytes_returned, 0);
         if (rc) {
-                cERROR(1, ("Send error in QFSInfo = %d", rc));
+                cFYI(1, ("Send error in QFSInfo = %d", rc));
         } else {                /* decode response */
                 rc = validate_t2((struct smb_t2_rsp *)pSMBr);
 
-                if (rc || (pSMBr->ByteCount < 24)) /* BB alsO CHEck enough total bytes returned */
+                if (rc || (pSMBr->ByteCount < 24))
                         rc = -EIO;      /* bad smb */
                 else {
                         __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
-                        cFYI(1,
-                                ("Decoding qfsinfo response.  BCC: %d  Offset %d",
-                                pSMBr->ByteCount, data_offset));
 
                         response_data =
                             (FILE_SYSTEM_INFO
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index fafbdbfa63a1..26b35b55f31b 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -450,13 +450,12 @@ checkSMB(struct smb_hdr *smb, __u16 mid, int length)
 
         if ((4 + len != smbCalcSize(smb))
             || (4 + len != (unsigned int)length)) {
-                return 0;
-        } else {
                 cERROR(1, ("smbCalcSize %x ", smbCalcSize(smb)));
                 cERROR(1,
                        ("bad smb size detected. The Mid=%d", smb->Mid));
                 return 1;
         }
+        return 0;
 }
 int
 is_valid_oplock_break(struct smb_hdr *buf)
diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index 873b812c0f40..32efa32774d2 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -868,7 +868,7 @@ unsigned int
 smbCalcSize(struct smb_hdr *ptr)
 {
         return (sizeof (struct smb_hdr) + (2 * ptr->WordCount) +
-                BCC(ptr));
+                2 /* size of the bcc field itself */ + BCC(ptr));
 }
 
 /* The following are taken from fs/ntfs/util.c */