[CIFS] when not using unix extensions, check for and set ATTR_READONLY on create and mkdir

When creating a directory on a CIFS share without POSIX extensions,
and the given mode has no write bits set, set the ATTR_READONLY bit.

When creating a file, set ATTR_READONLY if the create mode has no write
bits set and we're not using unix extensions.

There are some comments about this being problematic due to the VFS
splitting creates into 2 parts. I'm not sure what that's actually
talking about, but I'm assuming that it has something to do with how
mknod is implemented. In the simple case where we have no unix
extensions and we're just creating a regular file, there's no reason
we can't set ATTR_READONLY.

Signed-off-by: Jeff Layton <[e-mail]>
Signed-off-by: Steve French <[e-mail]>

fs/cifs/cifspdu.h

···
 #define OPEN_NO_RECALL          0x00400000
 #define OPEN_FREE_SPACE_QUERY   0x00800000	/* should be zero */
 #define CREATE_OPTIONS_MASK     0x007FFFFF
+#define CREATE_OPTION_READONLY	0x10000000
 #define CREATE_OPTION_SPECIAL   0x20000000   /* system. NB not sent over wire */
 
 /* ImpersonationLevel flags */

fs/cifs/cifssmb.c

···
 	else /* BB FIXME BB */
 		pSMB->FileAttributes = cpu_to_le16(0/*ATTR_NORMAL*/);
 
-	/* if ((omode & S_IWUGO) == 0)
-		pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);*/
-	/*  Above line causes problems due to vfs splitting create into two
-	    pieces - need to set mode after file created not while it is
-	    being created */
+	if (create_options & CREATE_OPTION_READONLY)
+		pSMB->FileAttributes |= cpu_to_le16(ATTR_READONLY);
 
 	/* BB FIXME BB */
 /*	pSMB->CreateOptions = cpu_to_le32(create_options &
···
 		pSMB->FileAttributes = cpu_to_le32(ATTR_SYSTEM);
 	else
 		pSMB->FileAttributes = cpu_to_le32(ATTR_NORMAL);
+
 	/* XP does not handle ATTR_POSIX_SEMANTICS */
 	/* but it helps speed up case sensitive checks for other
 	servers such as Samba */
 	if (tcon->ses->capabilities & CAP_UNIX)
 		pSMB->FileAttributes |= cpu_to_le32(ATTR_POSIX_SEMANTICS);
 
-	/* if ((omode & S_IWUGO) == 0)
-		pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);*/
-	/*  Above line causes problems due to vfs splitting create into two
-		pieces - need to set mode after file created not while it is
-		being created */
+	if (create_options & CREATE_OPTION_READONLY)
+		pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY);
+
 	pSMB->ShareAccess = cpu_to_le32(FILE_SHARE_ALL);
 	pSMB->CreateDisposition = cpu_to_le32(openDisposition);
 	pSMB->CreateOptions = cpu_to_le32(create_options & CREATE_OPTIONS_MASK);

fs/cifs/dir.c

···
 {
 	int rc = -ENOENT;
 	int xid;
+	int create_options = CREATE_NOT_DIR;
 	int oplock = 0;
 	int desiredAccess = GENERIC_READ | GENERIC_WRITE;
 	__u16 fileHandle;
···
 		FreeXid(xid);
 		return -ENOMEM;
 	}
+
+	mode &= ~current->fs->umask;
+
+	/*
+	 * if we're not using unix extensions, see if we need to set
+	 * ATTR_READONLY on the create call
+	 */
+	if (!pTcon->unix_ext && (mode & S_IWUGO) == 0)
+		create_options |= CREATE_OPTION_READONLY;
+
 	if (cifs_sb->tcon->ses->capabilities & CAP_NT_SMBS)
 		rc = CIFSSMBOpen(xid, pTcon, full_path, disposition,
-			 desiredAccess, CREATE_NOT_DIR,
+			 desiredAccess, create_options,
 			 &fileHandle, &oplock, buf, cifs_sb->local_nls,
 			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	else
···
 	if (rc == -EIO) {
 		/* old server, retry the open legacy style */
 		rc = SMBLegacyOpen(xid, pTcon, full_path, disposition,
-			desiredAccess, CREATE_NOT_DIR,
+			desiredAccess, create_options,
 			&fileHandle, &oplock, buf, cifs_sb->local_nls,
 			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
 	}
···
 		/* If Open reported that we actually created a file
 		then we now have to set the mode if possible */
 		if ((pTcon->unix_ext) && (oplock & CIFS_CREATE_ACTION)) {
-			mode &= ~current->fs->umask;
 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 				CIFSSMBUnixSetPerms(xid, pTcon, full_path, mode,
 					(__u64)current->fsuid,

fs/cifs/inode.c

···
 		  * failed to get it from the server or was set bogus */
 		if ((direntry->d_inode) && (direntry->d_inode->i_nlink < 2))
 				direntry->d_inode->i_nlink = 2;
+		mode &= ~current->fs->umask;
 		if (pTcon->unix_ext) {
-			mode &= ~current->fs->umask;
 			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
 				CIFSSMBUnixSetPerms(xid, pTcon, full_path,
 						    mode,
···
 						    CIFS_MOUNT_MAP_SPECIAL_CHR);
 			}
 		} else {
-			/* BB to be implemented via Windows secrty descriptors
-			   eg CIFSSMBWinSetPerms(xid, pTcon, full_path, mode,
-						 -1, -1, local_nls); */
+			if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) &&
+			    (mode & S_IWUGO) == 0) {
+				FILE_BASIC_INFO pInfo;
+				memset(&pInfo, 0, sizeof(pInfo));
+				pInfo.Attributes = cpu_to_le32(ATTR_READONLY);
+				CIFSSMBSetTimes(xid, pTcon, full_path,
+						&pInfo, cifs_sb->local_nls,
+						cifs_sb->mnt_cifs_flags &
+						CIFS_MOUNT_MAP_SPECIAL_CHR);
+			}
 			if (direntry->d_inode) {
 				direntry->d_inode->i_mode = mode;
 				direntry->d_inode->i_mode |= S_IFDIR;