on non-posix shares, clear write bits in mode when ATTR_READONLY is set

When mounting a share with posix extensions disabled,
cifs_get_inode_info turns off all the write bits in the mode for regular
files if ATTR_READONLY is set. Directories and other inode types,
however, can also have ATTR_READONLY set, but the mode gives no
indication of this.

This patch makes this apply to other inode types besides regular files.
It also cleans up how modes are set in cifs_get_inode_info for both the
"normal" and "dynperm" cases.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/inode.c

@@ -418,6 +418,7 @@ int cifs_get_inode_info(struct inode **pinode,
 	char *buf = NULL;
 	bool adjustTZ = false;
 	bool is_dfs_referral = false;
+	umode_t default_mode;
 
 	pTcon = cifs_sb->tcon;
 	cFYI(1, ("Getting info on %s", full_path));
@@ -530,47 +531,42 @@ int cifs_get_inode_info(struct inode **pinode,
 		inode->i_mtime.tv_sec += pTcon->ses->server->timeAdj;
 	}
 
-	/* set default mode. will override for dirs below */
-	if (atomic_read(&cifsInfo->inUse) == 0)
-		/* new inode, can safely set these fields */
-		inode->i_mode = cifs_sb->mnt_file_mode;
-	else /* since we set the inode type below we need to mask off
-	     to avoid strange results if type changes and both
-	     get orred in */
+	/* get default inode mode */
+	if (attr & ATTR_DIRECTORY)
+		default_mode = cifs_sb->mnt_dir_mode;
+	else
+		default_mode = cifs_sb->mnt_file_mode;
+
+	/* set permission bits */
+	if (atomic_read(&cifsInfo->inUse) == 0 ||
+	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) == 0)
+		inode->i_mode = default_mode;
+	else {
+		/* just reenable write bits if !ATTR_READONLY */
+		if ((inode->i_mode & S_IWUGO) == 0 &&
+		    (attr & ATTR_READONLY) == 0)
+			inode->i_mode |= (S_IWUGO & default_mode);
 			inode->i_mode &= ~S_IFMT;
-/*	if (attr & ATTR_REPARSE)  */
-	/* We no longer handle these as symlinks because we could not
-	   follow them due to the absolute path with drive letter */
-	if (attr & ATTR_DIRECTORY) {
-	/* override default perms since we do not do byte range locking
-	   on dirs */
-		inode->i_mode = cifs_sb->mnt_dir_mode;
-		inode->i_mode |= S_IFDIR;
-	} else if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) &&
-		   (cifsInfo->cifsAttrs & ATTR_SYSTEM) &&
-		   /* No need to le64 convert size of zero */
-		   (pfindData->EndOfFile == 0)) {
-		inode->i_mode = cifs_sb->mnt_file_mode;
+	}
+	/* clear write bits if ATTR_READONLY is set */
+	if (attr & ATTR_READONLY)
+		inode->i_mode &= ~S_IWUGO;
+
+	/* set inode type */
+	if ((attr & ATTR_SYSTEM) &&
+	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)) {
+		/* no need to fix endianness on 0 */
+		if (pfindData->EndOfFile == 0)
 			inode->i_mode |= S_IFIFO;
-/* BB Finish for SFU style symlinks and devices */
-	} else if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) &&
-		   (cifsInfo->cifsAttrs & ATTR_SYSTEM)) {
-		if (decode_sfu_inode(inode, le64_to_cpu(pfindData->EndOfFile),
+		else if (decode_sfu_inode(inode,
+				le64_to_cpu(pfindData->EndOfFile),
 				full_path, cifs_sb, xid))
-			cFYI(1, ("Unrecognized sfu inode type"));
-
-		cFYI(1, ("sfu mode 0%o", inode->i_mode));
+			cFYI(1, ("unknown SFU file type\n"));
 	} else {
+		if (attr & ATTR_DIRECTORY)
+			inode->i_mode |= S_IFDIR;
+		else
 			inode->i_mode |= S_IFREG;
-		/* treat dos attribute of read-only as read-only mode eg 555 */
-		if (cifsInfo->cifsAttrs & ATTR_READONLY)
-			inode->i_mode &= ~(S_IWUGO);
-		else if ((inode->i_mode & S_IWUGO) == 0)
-			/* the ATTR_READONLY flag may have been	*/
-			/* changed on server -- set any w bits	*/
-			/* allowed by mnt_file_mode		*/
-			inode->i_mode |= (S_IWUGO & cifs_sb->mnt_file_mode);
-	/* BB add code to validate if device or weird share or device type? */
 	}
 
 	spin_lock(&inode->i_lock);

fs/cifs/readdir.c

@@ -132,6 +132,7 @@ static void fill_in_inode(struct inode *tmp_inode, int new_buf_type,
 	__u32 attr;
 	__u64 allocation_size;
 	__u64 end_of_file;
+	umode_t default_mode;
 
 	/* save mtime and size */
 	local_mtime = tmp_inode->i_mtime;
@@ -187,48 +188,54 @@ static void fill_in_inode(struct inode *tmp_inode, int new_buf_type,
 	if (atomic_read(&cifsInfo->inUse) == 0) {
 		tmp_inode->i_uid = cifs_sb->mnt_uid;
 		tmp_inode->i_gid = cifs_sb->mnt_gid;
-		/* set default mode. will override for dirs below */
-		tmp_inode->i_mode = cifs_sb->mnt_file_mode;
-	} else {
-		/* mask off the type bits since it gets set
-		below and we do not want to get two type
-		bits set */
+	}
+
+	if (attr & ATTR_DIRECTORY)
+		default_mode = cifs_sb->mnt_dir_mode;
+	else
+		default_mode = cifs_sb->mnt_file_mode;
+
+	/* set initial permissions */
+	if ((atomic_read(&cifsInfo->inUse) == 0) ||
+	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DYNPERM) == 0)
+		tmp_inode->i_mode = default_mode;
+	else {
+		/* just reenable write bits if !ATTR_READONLY */
+		if ((tmp_inode->i_mode & S_IWUGO) == 0 &&
+		    (attr & ATTR_READONLY) == 0)
+			tmp_inode->i_mode |= (S_IWUGO & default_mode);
+
 		tmp_inode->i_mode &= ~S_IFMT;
 	}
 
-	if (attr & ATTR_DIRECTORY) {
-		*pobject_type = DT_DIR;
-		/* override default perms since we do not lock dirs */
-		if (atomic_read(&cifsInfo->inUse) == 0)
-			tmp_inode->i_mode = cifs_sb->mnt_dir_mode;
-		tmp_inode->i_mode |= S_IFDIR;
-	} else if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) &&
-		   (attr & ATTR_SYSTEM)) {
+	/* clear write bits if ATTR_READONLY is set */
+	if (attr & ATTR_READONLY)
+		tmp_inode->i_mode &= ~S_IWUGO;
+
+	/* set inode type */
+	if ((attr & ATTR_SYSTEM) &&
+	    (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)) {
 		if (end_of_file == 0)  {
-			*pobject_type = DT_FIFO;
 			tmp_inode->i_mode |= S_IFIFO;
+			*pobject_type = DT_FIFO;
 		} else {
-			/* rather than get the type here, we mark the
-			inode as needing revalidate and get the real type
-			(blk vs chr vs. symlink) later ie in lookup */
-			*pobject_type = DT_REG;
+			/*
+			 * trying to get the type can be slow, so just call
+			 * this a regular file for now, and mark for reval
+			 */
 			tmp_inode->i_mode |= S_IFREG;
+			*pobject_type = DT_REG;
 			cifsInfo->time = 0;
 		}
-/* we no longer mark these because we could not follow them */
-/*        } else if (attr & ATTR_REPARSE) {
-		*pobject_type = DT_LNK;
-		tmp_inode->i_mode |= S_IFLNK; */
 	} else {
-		*pobject_type = DT_REG;
+		if (attr & ATTR_DIRECTORY) {
+			tmp_inode->i_mode |= S_IFDIR;
+			*pobject_type = DT_DIR;
+		} else {
 			tmp_inode->i_mode |= S_IFREG;
-		if (attr & ATTR_READONLY)
-			tmp_inode->i_mode &= ~(S_IWUGO);
-		else if ((tmp_inode->i_mode & S_IWUGO) == 0)
-			/* the ATTR_READONLY flag may have been changed on   */
-			/* server -- set any w bits allowed by mnt_file_mode */
-			tmp_inode->i_mode |= (S_IWUGO & cifs_sb->mnt_file_mode);
-	} /* could add code here - to validate if device or weird share type? */
+			*pobject_type = DT_REG;
+		}
+	}
 
 	/* can not fill in nlink here as in qpathinfo version and Unx search */
 	if (atomic_read(&cifsInfo->inUse) == 0)