1 files changed, 141 insertions, 0 deletions
diff --git a/resize/banalysis.c b/resize/banalysis.c
new file mode 100644
index 00000000..233158b6
--- /dev/null
+++ b/resize/banalysis.c
@@ -0,0 +1,141 @@
+/*
+ * banalysis.c --- Analyze a filesystem for a block struct
+ *
+ * Copyright (C) 1997 Theodore Ts'o.  This file may be redistributed
+ * under the terms of the GNU Public License.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#ifdef HAVE_LINUX_FS_H
+#include <linux/fs.h>
+#endif
+#include <linux/ext2_fs.h>
+
+#include "ext2fs/ext2fs.h"
+
+#include "ext2fs/brel.h"
+#include "banalysis.h"
+
+struct process_block_struct {
+	struct ext2_block_analyzer_funcs *funcs;
+	struct ext2_inode_context *ctx;
+	void *private;
+};
+
+/*
+ * This function returns 1 if the inode's block entries actually
+ * contain block entries.
+ */
+static int inode_has_valid_blocks(struct ext2_inode *inode)
+{
+	/*
+	 * Only directories, regular files, and some symbolic links
+	 * have valid block entries.
+	 */
+	if (!LINUX_S_ISDIR(inode->i_mode) && !LINUX_S_ISREG(inode->i_mode) &&
+	    !LINUX_S_ISLNK(inode->i_mode))
+		return 0;
+	
+	/*
+	 * If the symbolic link is a "fast symlink", then the symlink
+	 * target is stored in the block entries.
+	 */
+	if (LINUX_S_ISLNK (inode->i_mode) && inode->i_blocks == 0 &&
+	    inode->i_size < EXT2_N_BLOCKS * sizeof (unsigned long))
+		return 0;
+
+	return 1;
+}
+
+static int process_block(ext2_filsys fs, blk_t	*block_nr,
+			 int blockcnt, blk_t ref_block,
+			 int ref_offset, void *private)
+{
+	struct process_block_struct *pb = private;
+	blk_t	new_block;
+	struct ext2_block_relocate_entry ent;
+
+	if (ref_block == 0)
+		ref_offset = blockcnt;
+
+	new_block = pb->funcs->block_analyze(fs, *block_nr, ref_block,
+					     ref_offset, pb->ctx, pb->private);
+	if (new_block) {
+		ent.new = new_block;
+		ent.offset = ref_offset;
+		if (ref_block) {
+			ent.owner.block_ref = ref_block;
+			ent.flags = 0;
+		} else {
+			ent.owner.inode_ref = pb->ctx->ino;
+			ent.flags = RELOCATE_INODE_REF;
+		}
+		ext2fs_brel_put(pb->ctx->brel, *block_nr, &ent);
+	}
+	return 0;
+}
+
+errcode_t ext2_block_analyze(ext2_filsys fs,
+			     struct ext2_block_analyzer_funcs *funcs,
+			     ext2_brel block_relocation_table,
+			     void *private)
+{
+	ino_t	ino;
+	struct ext2_inode inode;
+	errcode_t	retval;
+	struct process_block_struct pb;
+	struct ext2_inode_context ctx;
+	ext2_inode_scan	scan;
+	char		*block_buf;
+	
+	retval = ext2fs_open_inode_scan(fs, 0, &scan);
+	if (retval)
+		return retval;
+
+	pb.funcs = funcs;
+	pb.private = private;
+	pb.ctx = &ctx;
+	
+	block_buf = malloc(fs->blocksize * 3);
+	if (!block_buf)
+		return ENOMEM;
+
+	retval = ext2fs_get_next_inode(scan, &ino, &inode);
+	if (retval)
+		return retval;
+	ctx.ctx = private;
+	ctx.brel = block_relocation_table;
+	while (ino) {
+		if ((inode.i_links_count == 0) ||
+		    !inode_has_valid_blocks(&inode))
+			goto next;
+		
+		ctx.ino = ino;
+		ctx.inode = &inode;
+		ctx.error = 0;
+
+		if (funcs->pre_analyze &&
+		    !(*funcs->pre_analyze)(fs, &ctx, private))
+			goto next;
+
+		retval = ext2fs_block_iterate2(fs, ino, 0, block_buf,
+					      process_block, &pb);
+		if (retval)
+			return retval;
+
+		if (funcs->post_analyze) 
+			(funcs->post_analyze)(fs, &ctx, private);
+
+	next:
+		retval = ext2fs_get_next_inode(scan, &ino, &inode);
+		if (retval == EXT2_ET_BAD_BLOCK_IN_INODE_TABLE)
+			goto next;
+	}
+	return 0;
+}