[CIFS] Add support for legacy servers part 4

	Fix WriteX support for old servers which do not support large
	files.

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

1 files changed, 48 insertions, 18 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index ef455dda0473..b6c303f6373f 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1183,11 +1183,16 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
         char *smb_read_data;
         char __user *current_offset;
         struct smb_com_read_rsp *pSMBr;
+        int use_old_read = FALSE;
 
         xid = GetXid();
         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
         pTcon = cifs_sb->tcon;
 
+        if(pTcon->ses)
+                if((pTcon->ses->capabilities & CAP_LARGE_FILES) == 0)
+                        use_old_read = TRUE;
+
         if (file->private_data == NULL) {
                 FreeXid(xid);
                 return -EBADF;
@@ -1212,16 +1217,21 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data,
                                 if (rc != 0)
                                         break;
                         }
-
-                        rc = CIFSSMBRead(xid, pTcon,
-                                 open_file->netfid,
-                                 current_read_size, *poffset,
-                                 &bytes_read, &smb_read_data);
-                        if(rc == -EINVAL) {
+                        if(use_old_read)
                                 rc = SMBLegacyRead(xid, pTcon,
                                         open_file->netfid,
                                         current_read_size, *poffset,
                                         &bytes_read, &smb_read_data);
+                        else {
+                                rc = CIFSSMBRead(xid, pTcon,
+                                        open_file->netfid,
+                                        current_read_size, *poffset,
+                                        &bytes_read, &smb_read_data);
+                                if(rc == -EINVAL) {
+                                        use_old_read = TRUE;
+                                        rc = -EAGAIN;
+                                        continue;
+                                }
                         }
                         pSMBr = (struct smb_com_read_rsp *)smb_read_data;
                         if (copy_to_user(current_offset, 
@@ -1266,6 +1276,7 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
         int xid;
         char *current_offset;
         struct cifsFileInfo *open_file;
+        int use_old_read = FALSE;
 
         xid = GetXid();
         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
@@ -1276,6 +1287,9 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
                 return -EBADF;
         }
         open_file = (struct cifsFileInfo *)file->private_data;
+        if(pTcon->ses)
+                if((pTcon->ses->capabilities & CAP_LARGE_FILES) == 0)
+                        use_old_read = TRUE;
 
         if ((file->f_flags & O_ACCMODE) == O_WRONLY)
                 cFYI(1, ("attempting read on write only file instance"));
@@ -1294,16 +1308,23 @@ static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size,
                                 if (rc != 0)
                                         break;
                         }
-
-                        rc = CIFSSMBRead(xid, pTcon,
-                                 open_file->netfid,
-                                 current_read_size, *poffset,
-                                 &bytes_read, &current_offset);
-                        if(rc == -EINVAL) {
+                        if(use_old_read) 
                                 rc = SMBLegacyRead(xid, pTcon,
+                                         open_file->netfid,
+                                         current_read_size, *poffset,
+                                         &bytes_read, &current_offset);
+                        else {
+                                rc = CIFSSMBRead(xid, pTcon,
                                         open_file->netfid,
                                         current_read_size, *poffset,
                                         &bytes_read, &current_offset);
+                                /* check if server disavows support for
+                                   64 bit offsets */
+                                if(rc == -EINVAL) {
+                                        rc = -EAGAIN;
+                                        use_old_read = TRUE;
+                                        continue;
+                                }
                         }
                 }
                 if (rc || (bytes_read == 0)) {
@@ -1402,6 +1423,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
         struct smb_com_read_rsp *pSMBr;
         struct pagevec lru_pvec;
         struct cifsFileInfo *open_file;
+        int use_old_read = FALSE;
 
         xid = GetXid();
         if (file->private_data == NULL) {
@@ -1411,7 +1433,9 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
         open_file = (struct cifsFileInfo *)file->private_data;
         cifs_sb = CIFS_SB(file->f_dentry->d_sb);
         pTcon = cifs_sb->tcon;
-
+        if(pTcon->ses)
+                if((pTcon->ses->capabilities & CAP_LARGE_FILES) == 0)
+                        use_old_read = TRUE;
         pagevec_init(&lru_pvec, 0);
 
         for (i = 0; i < num_pages; ) {
@@ -1457,15 +1481,21 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
                                         break;
                         }
 
-                        rc = CIFSSMBRead(xid, pTcon,
-                                open_file->netfid,
-                                read_size, offset,
-                                &bytes_read, &smb_read_data);
-                        if (rc == -EINVAL) {
+                        if(use_old_read)
                                 rc = SMBLegacyRead(xid, pTcon,
                                         open_file->netfid,
                                         read_size, offset,
                                         &bytes_read, &smb_read_data);
+                        else {
+                                rc = CIFSSMBRead(xid, pTcon,
+                                        open_file->netfid,
+                                        read_size, offset,
+                                        &bytes_read, &smb_read_data);
+                                if(rc == -EINVAL) {
+                                        use_old_read = TRUE;
+                                        rc = -EAGAIN;
+                                        continue;
+                                }
                         }
 
                         /* BB more RC checks ? */