[PATCH] e2fsprogs: add ext2fs_extent_open2

[number9652 <number9652@yahoo.com>]

The patch below adds a function, ext2fs_extent_open2(), that behaves as ext2fs_extent_open(), but will use the user-supplied inode structure when opening an extent instead of reading the inode from disk.  It also changes several of the calls to extent_open() to use this enhancement.
---

diff --git a/e2fsprogs-1.41.5-orig/e2fsck/pass1.c b/e2fsprogs-1.41.5/e2fsck/pass1.c
index 3b05cf2..2968a3e 100644
--- a/e2fsprogs-1.41.5-orig/e2fsck/pass1.c
+++ b/e2fsprogs-1.41.5/e2fsck/pass1.c
@@ -180,7 +180,7 @@ int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
 	if (inode->i_flags & EXT4_EXTENTS_FL) {
 		if (inode->i_size > fs->blocksize)
 			return 0;
-		if (ext2fs_extent_open(fs, ino, &handle))
+		if (ext2fs_extent_open2(fs, ino, inode, &handle))
 			return 0;
 		i = 0;
 		if (ext2fs_extent_get_info(handle, &info) ||
@@ -1769,7 +1769,7 @@ static void check_blocks_extents(e2fsck_t ctx, struct problem_context *pctx,
 	ext2_ino_t		ino = pctx->ino;
 	errcode_t		retval;
 
-	pctx->errcode = ext2fs_extent_open(fs, ino, &ehandle);
+	pctx->errcode = ext2fs_extent_open2(fs, ino, inode, &ehandle);
 	if (pctx->errcode &&
 	    fix_problem(ctx, PR_1_READ_EXTENT, pctx)) {
 		e2fsck_clear_inode(ctx, ino, inode, 0, "check_blocks_extents");
diff --git a/e2fsprogs-1.41.5-orig/lib/ext2fs/block.c b/e2fsprogs-1.41.5/lib/ext2fs/block.c
index 6ac9379..de5342d 100644
--- a/e2fsprogs-1.41.5-orig/lib/ext2fs/block.c
+++ b/e2fsprogs-1.41.5/lib/ext2fs/block.c
@@ -367,7 +367,7 @@ errcode_t ext2fs_block_iterate2(ext2_filsys fs,
 		int			uninit;
 		unsigned int		j;
 
-		ctx.errcode = ext2fs_extent_open(fs, ino, &handle);
+		ctx.errcode = ext2fs_extent_open2(fs, ino, &inode, &handle);
 		if (ctx.errcode)
 			goto abort_exit;
 
diff --git a/e2fsprogs-1.41.5-orig/lib/ext2fs/bmap.c b/e2fsprogs-1.41.5/lib/ext2fs/bmap.c
index 4edf425..2a86439 100644
--- a/e2fsprogs-1.41.5-orig/lib/ext2fs/bmap.c
+++ b/e2fsprogs-1.41.5/lib/ext2fs/bmap.c
@@ -160,7 +160,7 @@ errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode,
 		struct ext2fs_extent	extent;
 		unsigned int		offset;
 
-		retval = ext2fs_extent_open(fs, ino, &handle);
+		retval = ext2fs_extent_open2(fs, ino, inode, &handle);
 		if (retval)
 			goto done;
 		if (bmap_flags & BMAP_SET) {
diff --git a/e2fsprogs-1.41.5-orig/lib/ext2fs/ext2fs.h b/e2fsprogs-1.41.5/lib/ext2fs/ext2fs.h
index d5026bc..08bfa03 100644
--- a/e2fsprogs-1.41.5-orig/lib/ext2fs/ext2fs.h
+++ b/e2fsprogs-1.41.5/lib/ext2fs/ext2fs.h
@@ -839,6 +839,9 @@ extern errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
 extern errcode_t ext2fs_extent_header_verify(void *ptr, int size);
 extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 				    ext2_extent_handle_t *handle);
+extern errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
+					struct ext2_inode *inode,
+					ext2_extent_handle_t *ret_handle);
 extern void ext2fs_extent_free(ext2_extent_handle_t handle);
 extern errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
 				   int flags, struct ext2fs_extent *extent);
diff --git a/e2fsprogs-1.41.5-orig/lib/ext2fs/extent.c b/e2fsprogs-1.41.5/lib/ext2fs/extent.c
index 143929e..37cd932 100644
--- a/e2fsprogs-1.41.5-orig/lib/ext2fs/extent.c
+++ b/e2fsprogs-1.41.5/lib/ext2fs/extent.c
@@ -180,32 +180,44 @@ extern void ext2fs_extent_free(ext2_extent_handle_t handle)
 extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 				    ext2_extent_handle_t *ret_handle)
 {
+	return ext2fs_extent_open2(fs, ino, NULL, ret_handle);
+}
+
+extern errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
+				    struct ext2_inode *inode,
+				    ext2_extent_handle_t *ret_handle)
+{
 	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);
 
-	if ((ino == 0) || (ino > fs->super->s_inodes_count))
-		return EXT2_ET_BAD_INODE_NUM;
+	if (!inode)
+		if ((ino == 0) || (ino > fs->super->s_inodes_count))
+			return EXT2_ET_BAD_INODE_NUM;
 
 	retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
 	if (retval)
 		return retval;
 	memset(handle, 0, sizeof(struct ext2_extent_handle));
 
-	retval = ext2fs_get_mem(isize, &handle->inode);
+	retval = ext2fs_get_mem(sizeof(struct ext2_inode), &handle->inode);
 	if (retval)
 		goto errout;
 
 	handle->ino = ino;
 	handle->fs = fs;
 
-	retval = ext2fs_read_inode_full(fs, ino, handle->inode, isize);
-	if (retval)
-		goto errout;
+	if (inode) {
+		memcpy(handle->inode, inode, sizeof(struct ext2_inode));
+	}
+	else {
+		retval = ext2fs_read_inode(fs, ino, handle->inode);
+		if (retval)
+			goto errout;
+	}
 
 	eh = (struct ext3_extent_header *) &handle->inode->i_block[0];