debugfs: add the ability to manipulate the extent tree directly

This commit adds the functionality which had previously only been in
the tst_extents command to debugfs.  The debugfs command extent_open
will open extent tree of a particular inode, and enables a series of
commands which will allow the user to interact with the extent tree
directly.  Once the extent tree is closed via extent_open(), these
additional commands will be disabled again.

This commit exports two new functions from lib/ext2fs/extent.c which
had previously been statically defined: ext2fs_extent_node_split() and
ext2fs_extent_goto2().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/debugfs/extent_inode.c b/debugfs/extent_inode.c
new file mode 100644
index 0000000..69628a9
--- /dev/null
+++ b/debugfs/extent_inode.c
@@ -0,0 +1,547 @@
+/*
+ * extent_inode.c --- direct extent tree manipulation
+ *
+ * Copyright (C) 2012 Theodore Ts'o.  This file may be redistributed
+ * under the terms of the GNU Public License.
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <time.h>
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include <sys/types.h>
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#else
+extern int optind;
+extern char *optarg;
+#endif
+
+#include "debugfs.h"
+
+ext2_ino_t	current_ino;
+ext2_extent_handle_t current_handle;
+
+static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
+{
+	if (desc)
+		printf("%s: ", desc);
+	printf("extent: lblk %llu--%llu, len %u, pblk %llu, flags: ",
+	       extent->e_lblk, extent->e_lblk + extent->e_len - 1,
+	       extent->e_len, extent->e_pblk);
+	if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
+		fputs("LEAF ", stdout);
+	if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+		fputs("UNINIT ", stdout);
+	if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
+		fputs("2ND_VISIT ", stdout);
+	if (!extent->e_flags)
+		fputs("(none)", stdout);
+	fputc('\n', stdout);
+
+}
+
+int common_extent_args_process(int argc, char *argv[], int min_argc,
+			       int max_argc, const char *cmd,
+			       const char *usage, int flags)
+{
+	if (common_args_process(argc, argv, min_argc, max_argc, cmd,
+				usage, flags))
+		return 1;
+
+	if (!current_handle) {
+		com_err(cmd, 0, "Extent handle not open");
+		return 1;
+	}
+	return 0;
+}
+
+static char *orig_prompt, *extent_prompt;
+
+void do_extent_open(int argc, char *argv[])
+{
+	struct ext3_extent_header *eh;
+	ext2_ino_t	inode;
+	int		i, ret;
+	errcode_t	retval;
+	char		*cp;
+
+	if (check_fs_open(argv[0]))
+		return;
+
+	if (argc == 1) {
+		if (current_ino)
+			printf("Current inode is %d\n", current_ino);
+		else
+			printf("No current inode\n");
+		return;
+	}
+
+	if (common_inode_args_process(argc, argv, &inode, 0))
+		return;
+
+	current_ino = 0;
+
+	retval = ext2fs_extent_open(current_fs, inode, &current_handle);
+	if (retval) {
+		com_err(argv[1], retval, "while opening extent handle");
+		return;
+	}
+
+	current_ino = inode;
+
+	orig_prompt = ss_get_prompt(sci_idx);
+	extent_prompt = malloc(strlen(orig_prompt) + 32);
+	strcpy(extent_prompt, orig_prompt);
+	cp = strchr(extent_prompt, ':');
+	if (cp)
+		*cp = 0;
+	sprintf(extent_prompt + strlen(extent_prompt), " (extent ino %d): ",
+		current_ino);
+	ss_add_request_table(sci_idx, &extent_cmds, 1, &ret);
+	ss_set_prompt(sci_idx, extent_prompt);
+	return;
+}
+
+void do_extent_close(int argc, char *argv[])
+{
+	int ret;
+
+	if (check_fs_open(argv[0]))
+		return;
+
+	if (!current_handle) {
+		com_err(argv[0], 0, "Extent handle not open");
+		return;
+	}
+
+	ext2fs_extent_free(current_handle);
+	current_handle = NULL;
+	current_ino = 0;
+	ss_delete_request_table(sci_idx, &extent_cmds, &ret);
+	ss_set_prompt(sci_idx, orig_prompt);
+	free(extent_prompt);
+	extent_prompt = NULL;
+}
+
+void generic_goto_node(char *cmd_name, int op)
+{
+	struct ext2fs_extent	extent;
+	errcode_t		retval;
+
+	if (check_fs_open(cmd_name))
+		return;
+
+	if (!current_handle) {
+		com_err(cmd_name, 0, "Extent handle not open");
+		return;
+	}
+
+	retval = ext2fs_extent_get(current_handle, op, &extent);
+	if (retval) {
+		com_err(cmd_name, retval, 0);
+		return;
+	}
+	dbg_print_extent(0, &extent);
+}
+
+void do_current_node(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
+}
+
+void do_root_node(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
+}
+
+void do_last_leaf(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
+}
+
+void do_first_sib(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
+}
+
+void do_last_sib(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
+}
+
+void do_next_sib(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
+}
+
+void do_prev_sib(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
+}
+
+void do_next_leaf(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
+}
+
+void do_prev_leaf(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
+}
+
+void do_next(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
+}
+
+void do_prev(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_PREV);
+}
+
+void do_up(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_UP);
+}
+
+void do_down(int argc, char *argv[])
+{
+	generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
+}
+
+void do_delete_node(int argc, char *argv[])
+{
+	struct ext2fs_extent extent;
+	errcode_t	retval;
+	int		err;
+
+	if (common_extent_args_process(argc, argv, 1, 1, "delete_node",
+				       "", CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	retval = ext2fs_extent_delete(current_handle, 0);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+
+	retval = ext2fs_extent_get(current_handle, EXT2_EXTENT_CURRENT,
+				   &extent);
+	if (retval)
+		return;
+	dbg_print_extent(0, &extent);
+}
+
+void do_replace_node(int argc, char *argv[])
+{
+	const char	*usage = "[--uninit] <lblk> <len> <pblk>";
+	errcode_t	retval;
+	struct ext2fs_extent extent;
+	int err;
+
+	if (common_extent_args_process(argc, argv, 3, 5, "replace_node",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	extent.e_flags = 0;
+
+	if (!strcmp(argv[1], "--uninit")) {
+		argc--;
+		argv++;
+		extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+	}
+
+	if (argc != 4) {
+		fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
+		return;
+	}
+
+	extent.e_lblk = parse_ulong(argv[1], argv[0], "logical block", &err);
+	if (err)
+		return;
+
+	extent.e_len = parse_ulong(argv[2], argv[0], "logical block", &err);
+	if (err)
+		return;
+
+	extent.e_pblk = parse_ulong(argv[3], argv[0], "logical block", &err);
+	if (err)
+		return;
+
+	retval = ext2fs_extent_replace(current_handle, 0, &extent);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+	do_current_node(argc, argv);
+}
+
+void do_split_node(int argc, char *argv[])
+{
+	errcode_t	retval;
+	struct ext2fs_extent extent;
+	int err;
+
+	if (common_extent_args_process(argc, argv, 1, 1, "split_node",
+				       "", CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	retval = ext2fs_extent_node_split(current_handle);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+	do_current_node(argc, argv);
+}
+
+void do_insert_node(int argc, char *argv[])
+{
+	const char	*usage = "[--after] [--uninit] <lblk> <len> <pblk>";
+	errcode_t	retval;
+	struct ext2fs_extent extent;
+	char *cmd;
+	int err;
+	int flags = 0;
+
+	if (common_extent_args_process(argc, argv, 3, 6, "insert_node",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	cmd = argv[0];
+
+	extent.e_flags = 0;
+
+	while (argc > 2) {
+		if (!strcmp(argv[1], "--after")) {
+			argc--;
+			argv++;
+			flags |= EXT2_EXTENT_INSERT_AFTER;
+			continue;
+		}
+		if (!strcmp(argv[1], "--uninit")) {
+			argc--;
+			argv++;
+			extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
+			continue;
+		}
+		break;
+	}
+
+	if (argc != 4) {
+		fprintf(stderr, "usage: %s %s\n", cmd, usage);
+		return;
+	}
+
+	extent.e_lblk = parse_ulong(argv[1], cmd,
+				    "logical block", &err);
+	if (err)
+		return;
+
+	extent.e_len = parse_ulong(argv[2], cmd,
+				    "length", &err);
+	if (err)
+		return;
+
+	extent.e_pblk = parse_ulong(argv[3], cmd,
+				    "pysical block", &err);
+	if (err)
+		return;
+
+	retval = ext2fs_extent_insert(current_handle, flags, &extent);
+	if (retval) {
+		com_err(cmd, retval, 0);
+		return;
+	}
+	do_current_node(argc, argv);
+}
+
+void do_set_bmap(int argc, char **argv)
+{
+	const char	*usage = "[--uninit] <lblk> <pblk>";
+	struct ext2fs_extent extent;
+	errcode_t	retval;
+	blk_t		logical;
+	blk_t		physical;
+	char		*cmd = argv[0];
+	int		flags = 0;
+	int		err;
+
+	if (common_extent_args_process(argc, argv, 3, 5, "set_bmap",
+				       usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
+		return;
+
+	if (argc > 2 && !strcmp(argv[1], "--uninit")) {
+		argc--;
+		argv++;
+		flags |= EXT2_EXTENT_SET_BMAP_UNINIT;
+	}
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s %s\n", cmd, usage);
+		return;
+	}
+
+	logical = parse_ulong(argv[1], cmd,
+				    "logical block", &err);
+	if (err)
+		return;
+
+	physical = parse_ulong(argv[2], cmd,
+				    "physical block", &err);
+	if (err)
+		return;
+
+	retval = ext2fs_extent_set_bmap(current_handle, logical,
+					(blk64_t) physical, flags);
+	if (retval) {
+		com_err(cmd, retval, 0);
+		return;
+	}
+
+	retval = ext2fs_extent_get(current_handle, EXT2_EXTENT_CURRENT,
+				   &extent);
+	if (retval)
+		return;
+	dbg_print_extent(0, &extent);
+}
+
+void do_print_all(int argc, char **argv)
+{
+	const char	*usage = "[--leaf-only|--reverse|--reverse-leaf]";
+	struct ext2fs_extent	extent;
+	errcode_t		retval;
+	errcode_t		end_err = EXT2_ET_EXTENT_NO_NEXT;
+	int			op = EXT2_EXTENT_NEXT;
+	int			first_op = EXT2_EXTENT_ROOT;
+
+
+	if (common_extent_args_process(argc, argv, 1, 2, "print_all",
+				       usage, 0))
+		return;
+
+	if (argc == 2) {
+		if (!strcmp(argv[1], "--leaf-only"))
+			op = EXT2_EXTENT_NEXT_LEAF;
+		else if (!strcmp(argv[1], "--reverse")) {
+			op = EXT2_EXTENT_PREV;
+			first_op = EXT2_EXTENT_LAST_LEAF;
+			end_err = EXT2_ET_EXTENT_NO_PREV;
+		} else if (!strcmp(argv[1], "--reverse-leaf")) {
+			op = EXT2_EXTENT_PREV_LEAF;
+			first_op = EXT2_EXTENT_LAST_LEAF;
+			end_err = EXT2_ET_EXTENT_NO_PREV;
+		} else {
+			fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
+			return;
+		}
+	}
+
+	retval = ext2fs_extent_get(current_handle, first_op, &extent);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+	dbg_print_extent(0, &extent);
+
+	while (1) {
+		retval = ext2fs_extent_get(current_handle, op, &extent);
+		if (retval == end_err)
+			break;
+
+		if (retval) {
+			com_err(argv[0], retval, 0);
+			return;
+		}
+		dbg_print_extent(0, &extent);
+	}
+}
+
+void do_fix_parents(int argc, char **argv)
+{
+	struct ext2fs_extent	extent;
+	struct ext2_extent_info	info;
+	errcode_t		retval;
+
+	if (common_extent_args_process(argc, argv, 1, 1, "fix_parents", "",
+				       CHECK_FS_RW))
+		return;
+
+	retval = ext2fs_extent_fix_parents(current_handle);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+}
+
+void do_info(int argc, char **argv)
+{
+	struct ext2fs_extent	extent;
+	struct ext2_extent_info	info;
+	errcode_t		retval;
+
+	if (common_extent_args_process(argc, argv, 1, 1, "info", "", 0))
+		return;
+
+	retval = ext2fs_extent_get_info(current_handle, &info);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+
+	retval = ext2fs_extent_get(current_handle,
+				   EXT2_EXTENT_CURRENT, &extent);
+	if (retval) {
+		com_err(argv[0], retval, 0);
+		return;
+	}
+
+	dbg_print_extent(0, &extent);
+
+	printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
+	       info.curr_entry, info.num_entries, info.max_entries,
+	       info.bytes_avail, info.curr_level, info.max_depth);
+	printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
+	       info.max_pblk);
+	printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
+	       info.max_uninit_len);
+}
+
+void do_goto_block(int argc, char **argv)
+{
+	struct ext2fs_extent	extent;
+	errcode_t		retval;
+	int			op = EXT2_EXTENT_NEXT_LEAF;
+	blk64_t			blk;
+	int			level = 0, err;
+
+	if (common_extent_args_process(argc, argv, 2, 3, "goto_block",
+				       "block [level]", 0))
+		return;
+
+	if (strtoblk(argv[0], argv[1], &blk))
+		return;
+
+	if (argc == 3) {
+		level = parse_ulong(argv[2], argv[0], "level", &err);
+		if (err)
+			return;
+	}
+
+	retval = ext2fs_extent_goto2(current_handle, level, (blk64_t) blk);
+
+	if (retval) {
+		com_err(argv[0], retval,
+			"while trying to go to block %llu, level %d",
+			(unsigned long long) blk, level);
+		return;
+	}
+
+	generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
+}