ext4: rename: create ext4_renament structure for local vars

Need to split up ext4_rename() into helpers but there are too many local
variables involved, so create a new structure.  This also, apparently,
makes the generated code size slightly smaller.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>

fs/ext4/namei.c

@@ -3000,6 +3000,22 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
 	return ext4_get_first_inline_block(inode, parent_de, retval);
 }
 
+struct ext4_renament {
+	struct inode *dir;
+	struct dentry *dentry;
+	struct inode *inode;
+
+	/* entry for "dentry" */
+	struct buffer_head *bh;
+	struct ext4_dir_entry_2 *de;
+	int inlined;
+
+	/* entry for ".." in inode if it's a directory */
+	struct buffer_head *dir_bh;
+	struct ext4_dir_entry_2 *parent_de;
+	int dir_inlined;
+};
+
 /*
  * Anybody can rename anything with this: the permission checks are left to the
  * higher-level routines.
@@ -3012,193 +3028,194 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		       struct inode *new_dir, struct dentry *new_dentry)
 {
 	handle_t *handle = NULL;
-	struct inode *old_inode, *new_inode;
-	struct buffer_head *old_bh, *new_bh, *dir_bh;
-	struct ext4_dir_entry_2 *old_de, *new_de;
+	struct ext4_renament old = {
+		.dir = old_dir,
+		.dentry = old_dentry,
+		.inode = old_dentry->d_inode,
+	};
+	struct ext4_renament new = {
+		.dir = new_dir,
+		.dentry = new_dentry,
+		.inode = new_dentry->d_inode,
+	};
 	int retval;
-	int inlined = 0, new_inlined = 0;
-	struct ext4_dir_entry_2 *parent_de;
-
-	dquot_initialize(old_dir);
-	dquot_initialize(new_dir);
 
-	old_bh = new_bh = dir_bh = NULL;
+	dquot_initialize(old.dir);
+	dquot_initialize(new.dir);
 
 	/* Initialize quotas before so that eventual writes go
 	 * in separate transaction */
-	if (new_dentry->d_inode)
-		dquot_initialize(new_dentry->d_inode);
+	if (new.inode)
+		dquot_initialize(new.inode);
 
-	old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
+	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
 	/*
 	 *  Check for inode number is _not_ due to possible IO errors.
 	 *  We might rmdir the source, keep it as pwd of some process
 	 *  and merrily kill the link to whatever was created under the
 	 *  same name. Goodbye sticky bit ;-<
 	 */
-	old_inode = old_dentry->d_inode;
 	retval = -ENOENT;
-	if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
+	if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
 		goto end_rename;
 
-	new_inode = new_dentry->d_inode;
-	new_bh = ext4_find_entry(new_dir, &new_dentry->d_name,
-				 &new_de, &new_inlined);
-	if (new_bh) {
-		if (!new_inode) {
-			brelse(new_bh);
-			new_bh = NULL;
+	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
+				 &new.de, &new.inlined);
+	if (new.bh) {
+		if (!new.inode) {
+			brelse(new.bh);
+			new.bh = NULL;
 		}
 	}
-	if (new_inode && !test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
-		ext4_alloc_da_blocks(old_inode);
+	if (new.inode && !test_opt(new.dir->i_sb, NO_AUTO_DA_ALLOC))
+		ext4_alloc_da_blocks(old.inode);
 
-	handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
-		(2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
+	handle = ext4_journal_start(old.dir, EXT4_HT_DIR,
+		(2 * EXT4_DATA_TRANS_BLOCKS(old.dir->i_sb) +
 		 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
 	if (IS_ERR(handle))
 		return PTR_ERR(handle);
 
-	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+	if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir))
 		ext4_handle_sync(handle);
 
-	if (S_ISDIR(old_inode->i_mode)) {
-		if (new_inode) {
+	if (S_ISDIR(old.inode->i_mode)) {
+		if (new.inode) {
 			retval = -ENOTEMPTY;
-			if (!empty_dir(new_inode))
+			if (!empty_dir(new.inode))
 				goto end_rename;
 		}
 		retval = -EIO;
-		dir_bh = ext4_get_first_dir_block(handle, old_inode,
-						  &retval, &parent_de,
-						  &inlined);
-		if (!dir_bh)
+		old.dir_bh = ext4_get_first_dir_block(handle, old.inode,
+						  &retval, &old.parent_de,
+						  &old.dir_inlined);
+		if (!old.dir_bh)
 			goto end_rename;
-		if (le32_to_cpu(parent_de->inode) != old_dir->i_ino)
+		if (le32_to_cpu(old.parent_de->inode) != old.dir->i_ino)
 			goto end_rename;
 		retval = -EMLINK;
-		if (!new_inode && new_dir != old_dir &&
-		    EXT4_DIR_LINK_MAX(new_dir))
+		if (!new.inode && new.dir != old.dir &&
+		    EXT4_DIR_LINK_MAX(new.dir))
 			goto end_rename;
-		BUFFER_TRACE(dir_bh, "get_write_access");
-		retval = ext4_journal_get_write_access(handle, dir_bh);
+		BUFFER_TRACE(old.dir_bh, "get_write_access");
+		retval = ext4_journal_get_write_access(handle, old.dir_bh);
 		if (retval)
 			goto end_rename;
 	}
-	if (!new_bh) {
-		retval = ext4_add_entry(handle, new_dentry, old_inode);
+	if (!new.bh) {
+		retval = ext4_add_entry(handle, new.dentry, old.inode);
 		if (retval)
 			goto end_rename;
 	} else {
-		BUFFER_TRACE(new_bh, "get write access");
-		retval = ext4_journal_get_write_access(handle, new_bh);
+		BUFFER_TRACE(new.bh, "get write access");
+		retval = ext4_journal_get_write_access(handle, new.bh);
 		if (retval)
 			goto end_rename;
-		new_de->inode = cpu_to_le32(old_inode->i_ino);
-		if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
+		new.de->inode = cpu_to_le32(old.inode->i_ino);
+		if (EXT4_HAS_INCOMPAT_FEATURE(new.dir->i_sb,
 					      EXT4_FEATURE_INCOMPAT_FILETYPE))
-			new_de->file_type = old_de->file_type;
-		new_dir->i_version++;
-		new_dir->i_ctime = new_dir->i_mtime =
-					ext4_current_time(new_dir);
-		ext4_mark_inode_dirty(handle, new_dir);
-		BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
-		if (!new_inlined) {
+			new.de->file_type = old.de->file_type;
+		new.dir->i_version++;
+		new.dir->i_ctime = new.dir->i_mtime =
+					ext4_current_time(new.dir);
+		ext4_mark_inode_dirty(handle, new.dir);
+		BUFFER_TRACE(new.bh, "call ext4_handle_dirty_metadata");
+		if (!new.inlined) {
 			retval = ext4_handle_dirty_dirent_node(handle,
-							       new_dir, new_bh);
+							       new.dir, new.bh);
 			if (unlikely(retval)) {
-				ext4_std_error(new_dir->i_sb, retval);
+				ext4_std_error(new.dir->i_sb, retval);
 				goto end_rename;
 			}
 		}
-		brelse(new_bh);
-		new_bh = NULL;
+		brelse(new.bh);
+		new.bh = NULL;
 	}
 
 	/*
 	 * Like most other Unix systems, set the ctime for inodes on a
 	 * rename.
 	 */
-	old_inode->i_ctime = ext4_current_time(old_inode);
-	ext4_mark_inode_dirty(handle, old_inode);
+	old.inode->i_ctime = ext4_current_time(old.inode);
+	ext4_mark_inode_dirty(handle, old.inode);
 
 	/*
 	 * ok, that's it
 	 */
-	if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
-	    old_de->name_len != old_dentry->d_name.len ||
-	    strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
-	    (retval = ext4_delete_entry(handle, old_dir,
-					old_de, old_bh)) == -ENOENT) {
-		/* old_de could have moved from under us during htree split, so
+	if (le32_to_cpu(old.de->inode) != old.inode->i_ino ||
+	    old.de->name_len != old.dentry->d_name.len ||
+	    strncmp(old.de->name, old.dentry->d_name.name, old.de->name_len) ||
+	    (retval = ext4_delete_entry(handle, old.dir,
+					old.de, old.bh)) == -ENOENT) {
+		/* old.de could have moved from under us during htree split, so
 		 * make sure that we are deleting the right entry.  We might
 		 * also be pointing to a stale entry in the unused part of
-		 * old_bh so just checking inum and the name isn't enough. */
+		 * old.bh so just checking inum and the name isn't enough. */
 		struct buffer_head *old_bh2;
 		struct ext4_dir_entry_2 *old_de2;
 
-		old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name,
+		old_bh2 = ext4_find_entry(old.dir, &old.dentry->d_name,
 					  &old_de2, NULL);
 		if (old_bh2) {
-			retval = ext4_delete_entry(handle, old_dir,
+			retval = ext4_delete_entry(handle, old.dir,
 						   old_de2, old_bh2);
 			brelse(old_bh2);
 		}
 	}
 	if (retval) {
-		ext4_warning(old_dir->i_sb,
+		ext4_warning(old.dir->i_sb,
 				"Deleting old file (%lu), %d, error=%d",
-				old_dir->i_ino, old_dir->i_nlink, retval);
+				old.dir->i_ino, old.dir->i_nlink, retval);
 	}
 
-	if (new_inode) {
-		ext4_dec_count(handle, new_inode);
-		new_inode->i_ctime = ext4_current_time(new_inode);
+	if (new.inode) {
+		ext4_dec_count(handle, new.inode);
+		new.inode->i_ctime = ext4_current_time(new.inode);
 	}
-	old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
-	ext4_update_dx_flag(old_dir);
-	if (dir_bh) {
-		parent_de->inode = cpu_to_le32(new_dir->i_ino);
-		BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
-		if (!inlined) {
-			if (is_dx(old_inode)) {
+	old.dir->i_ctime = old.dir->i_mtime = ext4_current_time(old.dir);
+	ext4_update_dx_flag(old.dir);
+	if (old.dir_bh) {
+		old.parent_de->inode = cpu_to_le32(new.dir->i_ino);
+		BUFFER_TRACE(old.dir_bh, "call ext4_handle_dirty_metadata");
+		if (!old.dir_inlined) {
+			if (is_dx(old.inode)) {
 				retval = ext4_handle_dirty_dx_node(handle,
-								   old_inode,
-								   dir_bh);
+								   old.inode,
+								   old.dir_bh);
 			} else {
 				retval = ext4_handle_dirty_dirent_node(handle,
-							old_inode, dir_bh);
+							old.inode, old.dir_bh);
 			}
 		} else {
-			retval = ext4_mark_inode_dirty(handle, old_inode);
+			retval = ext4_mark_inode_dirty(handle, old.inode);
 		}
 		if (retval) {
-			ext4_std_error(old_dir->i_sb, retval);
+			ext4_std_error(old.dir->i_sb, retval);
 			goto end_rename;
 		}
-		ext4_dec_count(handle, old_dir);
-		if (new_inode) {
+		ext4_dec_count(handle, old.dir);
+		if (new.inode) {
 			/* checked empty_dir above, can't have another parent,
 			 * ext4_dec_count() won't work for many-linked dirs */
-			clear_nlink(new_inode);
+			clear_nlink(new.inode);
 		} else {
-			ext4_inc_count(handle, new_dir);
-			ext4_update_dx_flag(new_dir);
-			ext4_mark_inode_dirty(handle, new_dir);
+			ext4_inc_count(handle, new.dir);
+			ext4_update_dx_flag(new.dir);
+			ext4_mark_inode_dirty(handle, new.dir);
 		}
 	}
-	ext4_mark_inode_dirty(handle, old_dir);
-	if (new_inode) {
-		ext4_mark_inode_dirty(handle, new_inode);
-		if (!new_inode->i_nlink)
-			ext4_orphan_add(handle, new_inode);
+	ext4_mark_inode_dirty(handle, old.dir);
+	if (new.inode) {
+		ext4_mark_inode_dirty(handle, new.inode);
+		if (!new.inode->i_nlink)
+			ext4_orphan_add(handle, new.inode);
 	}
 	retval = 0;
 
 end_rename:
-	brelse(dir_bh);
-	brelse(old_bh);
-	brelse(new_bh);
+	brelse(old.dir_bh);
+	brelse(old.bh);
+	brelse(new.bh);
 	if (handle)
 		ext4_journal_stop(handle);
 	return retval;