From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 2 Jun 2008 04:08:19 +0000 (-0400)
Subject: ext2fs_extent_open: If the inode is empty, initialize the extent tree
X-Git-Tag: android-x86-6.0-r1~26^2~1395
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=aa8e2f1c31374bfc6e479aea008896d179b100b4;p=android-x86%2Fexternal-e2fsprogs.git

ext2fs_extent_open: If the inode is empty, initialize the extent tree

If the inode's i_block[] array is completely empty, create an empty
extent tree in the in-core inode and set the EXT4_EXTENT_FL inode
flag.  This makes it easy to create a new inode using extents.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c
index b669e29b..18e9aca7 100644
--- a/lib/ext2fs/extent.c
+++ b/lib/ext2fs/extent.c
@@ -176,6 +176,7 @@ extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 	struct ext2_extent_handle	*handle;
 	errcode_t			retval;
 	int				isize = EXT2_INODE_SIZE(fs->super);
+	int				i;
 	struct ext3_extent_header	*eh;
 
 	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
@@ -199,11 +200,24 @@ extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 	if (retval)
 		goto errout;
 
+	eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
+
+	for (i=0; i < EXT2_N_BLOCKS; i++)
+		if (handle->inode->i_block[i])
+			break;
+	if (i >= EXT2_N_BLOCKS) {
+		eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
+		eh->eh_depth = 0;
+		eh->eh_entries = 0;
+		i = (sizeof(handle->inode->i_block) - sizeof(*eh)) /
+			sizeof(struct ext3_extent);
+		eh->eh_max = ext2fs_cpu_to_le16(i);
+		handle->inode->i_flags |= EXT4_EXTENTS_FL;
+	}
+
 	if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
 		return EXT2_ET_INODE_NOT_EXTENT;
 
-	eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
-
 	retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
 	if (retval)
 		return (retval);
@@ -967,7 +981,8 @@ void do_delete_node(int argc, char *argv[])
 		com_err(argv[0], retval, 0);
 		return;
 	}
-	do_current_node(argc, argv);
+	if (current_handle->path && current_handle->path[0].curr)
+		do_current_node(argc, argv);
 }
 
 void do_replace_node(int argc, char *argv[])