[CIFS] Allow reset of file to ATTR_NORMAL when archive bit not set

When a file had a dos attribute of 0x1 (readonly - but dos attribute
of archive was not set) - doing chmod 0777 or equivalent would
try to set a dos attribute of 0 (which some servers ignore)
rather than ATTR_NORMAL (0x20) which most servers accept.
Does not affect servers which support the CIFS Unix Extensions.

Acked-by: Prasad Potluri <pvp@us.ibm.com>
Acked-by: Shirish Pargaonkar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index 1cbe561..5d1f487 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -6,7 +6,10 @@
 (which we are about to overwrite anyway) when writing out file opened rw.
 When DOS attribute of file on non-Unix server's file changes on the server side
 from read-only back to read-write, reflect this change in default file mode
-(we had been leaving a file's mode read-only until the inode were reloaded)
+(we had been leaving a file's mode read-only until the inode were reloaded).
+Allow setting of attribute back to ATTR_NORMAL (removing readonly dos attribute
+when archive dos attribute not set and we are changing mode back to writeable
+on server which does not support the Unix Extensions).
 
 Version 1.47
 ------------
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index e75a844..f414526 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1196,6 +1196,7 @@
 	struct cifsFileInfo *open_file = NULL;
 	FILE_BASIC_INFO time_buf;
 	int set_time = FALSE;
+	int set_dosattr = FALSE;
 	__u64 mode = 0xFFFFFFFFFFFFFFFFULL;
 	__u64 uid = 0xFFFFFFFFFFFFFFFFULL;
 	__u64 gid = 0xFFFFFFFFFFFFFFFFULL;
@@ -1332,15 +1333,23 @@
 	else if (attrs->ia_valid & ATTR_MODE) {
 		rc = 0;
 		if ((mode & S_IWUGO) == 0) /* not writeable */ {
-			if ((cifsInode->cifsAttrs & ATTR_READONLY) == 0)
+			if ((cifsInode->cifsAttrs & ATTR_READONLY) == 0) {
+				set_dosattr = TRUE;
 				time_buf.Attributes =
 					cpu_to_le32(cifsInode->cifsAttrs |
 						    ATTR_READONLY);
+			}
 		} else if ((mode & S_IWUGO) == S_IWUGO) {
-			if (cifsInode->cifsAttrs & ATTR_READONLY)
+			if (cifsInode->cifsAttrs & ATTR_READONLY) {
+				set_dosattr = TRUE;
 				time_buf.Attributes =
 					cpu_to_le32(cifsInode->cifsAttrs &
 						    (~ATTR_READONLY));
+				/* Windows ignores set to zero */
+				if(time_buf.Attributes == 0)
+					time_buf.Attributes |= 
+						cpu_to_le32(ATTR_NORMAL);
+			}
 		}
 		/* BB to be implemented -
 		   via Windows security descriptors or streams */
@@ -1378,7 +1387,7 @@
 	} else
 		time_buf.ChangeTime = 0;
 
-	if (set_time || time_buf.Attributes) {
+	if (set_time || set_dosattr) {
 		time_buf.CreationTime = 0;	/* do not change */
 		/* In the future we should experiment - try setting timestamps
 		   via Handle (SetFileInfo) instead of by path */