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authorChris Mason <chris.mason@oracle.com>2011-10-27 22:02:19 -0400
committerChris Mason <chris.mason@oracle.com>2011-10-27 22:38:02 -0400
commit18c970767f21714efcbfe8121d30962c9b262545 (patch)
tree932985e764a4cedbc5b83b15421bb8d180f80d74
parentb670b9285efb2cd5b8a1668d6e80727d03e2a3d2 (diff)
btrfs-progs: add a utility to corrupt a single block
-rw-r--r--Makefile5
-rw-r--r--btrfs-corrupt-block.c221
2 files changed, 225 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index a5024f1b..96e20020 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@ LIBS=-luuid
RESTORE_LIBS=-lz
progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \
- btrfs btrfs-map-logical restore find-root calc-size
+ btrfs btrfs-map-logical restore find-root calc-size btrfs-corrupt-block
# make C=1 to enable sparse
ifdef C
@@ -79,6 +79,9 @@ btrfstune: $(objects) btrfstune.o
btrfs-map-logical: $(objects) btrfs-map-logical.o
$(CC) $(CFLAGS) -o btrfs-map-logical $(objects) btrfs-map-logical.o $(LDFLAGS) $(LIBS)
+btrfs-corrupt-block: $(objects) btrfs-corrupt-block.o
+ $(CC) $(CFLAGS) -o btrfs-corrupt-block $(objects) btrfs-corrupt-block.o $(LDFLAGS) $(LIBS)
+
btrfs-image: $(objects) btrfs-image.o
$(CC) $(CFLAGS) -o btrfs-image $(objects) btrfs-image.o -lpthread -lz $(LDFLAGS) $(LIBS)
diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
new file mode 100644
index 00000000..ace61c13
--- /dev/null
+++ b/btrfs-corrupt-block.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2009 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#define _XOPEN_SOURCE 500
+#define _GNU_SOURCE 1
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <getopt.h>
+#include "kerncompat.h"
+#include "ctree.h"
+#include "volumes.h"
+#include "disk-io.h"
+#include "print-tree.h"
+#include "transaction.h"
+#include "list.h"
+#include "version.h"
+
+/* we write the mirror info to stdout unless they are dumping the data
+ * to stdout
+ * */
+static FILE *info_file;
+
+struct extent_buffer *debug_corrupt_block(struct btrfs_root *root, u64 bytenr,
+ u32 blocksize, int copy)
+{
+ int ret;
+ struct extent_buffer *eb;
+ u64 length;
+ struct btrfs_multi_bio *multi = NULL;
+ struct btrfs_device *device;
+ int num_copies;
+ int mirror_num = 1;
+
+ eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
+ if (!eb)
+ return NULL;
+
+ length = blocksize;
+ while (1) {
+ ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
+ eb->start, &length, &multi, mirror_num);
+ BUG_ON(ret);
+ device = multi->stripes[0].dev;
+ eb->fd = device->fd;
+ device->total_ios++;
+ eb->dev_bytenr = multi->stripes[0].physical;
+
+ fprintf(info_file, "mirror %d logical %Lu physical %Lu "
+ "device %s\n", mirror_num, (unsigned long long)bytenr,
+ (unsigned long long)eb->dev_bytenr, device->name);
+ kfree(multi);
+
+ if (!copy || mirror_num == copy) {
+ ret = read_extent_from_disk(eb);
+ printf("corrupting %llu copy %d\n", eb->start,
+ mirror_num);
+ memset(eb->data, 0, eb->len);
+ write_extent_to_disk(eb);
+ fsync(eb->fd);
+ }
+
+ num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
+ eb->start, eb->len);
+ if (num_copies == 1)
+ break;
+
+ mirror_num++;
+ if (mirror_num > num_copies)
+ break;
+ }
+ return eb;
+}
+
+static void print_usage(void)
+{
+ fprintf(stderr, "usage: btrfs-map-logical [options] mount_point\n");
+ fprintf(stderr, "\t-l Logical extent to map\n");
+ fprintf(stderr, "\t-c Copy of the extent to read (usually 1 or 2)\n");
+ fprintf(stderr, "\t-o Output file to hold the extent\n");
+ fprintf(stderr, "\t-b Number of bytes to read\n");
+ exit(1);
+}
+
+static struct option long_options[] = {
+ /* { "byte-count", 1, NULL, 'b' }, */
+ { "logical", 1, NULL, 'l' },
+ { "copy", 1, NULL, 'c' },
+ { "bytes", 1, NULL, 'b' },
+ { 0, 0, 0, 0}
+};
+
+int main(int ac, char **av)
+{
+ struct cache_tree root_cache;
+ struct btrfs_root *root;
+ struct extent_buffer *eb;
+ char *dev;
+ char *output_file = NULL;
+ u64 logical = 0;
+ int ret = 0;
+ int option_index = 0;
+ int copy = 0;
+ u64 bytes = 4096;
+ int out_fd = 0;
+ int err;
+
+ while(1) {
+ int c;
+ c = getopt_long(ac, av, "l:c:", long_options,
+ &option_index);
+ if (c < 0)
+ break;
+ switch(c) {
+ case 'l':
+ logical = atoll(optarg);
+ if (logical == 0) {
+ fprintf(stderr,
+ "invalid extent number\n");
+ print_usage();
+ }
+ break;
+ case 'c':
+ copy = atoi(optarg);
+ if (copy == 0) {
+ fprintf(stderr,
+ "invalid copy number\n");
+ print_usage();
+ }
+ break;
+ case 'b':
+ bytes = atoll(optarg);
+ if (bytes == 0) {
+ fprintf(stderr,
+ "invalid byte count\n");
+ print_usage();
+ }
+ break;
+ default:
+ print_usage();
+ }
+ }
+ ac = ac - optind;
+ if (ac == 0)
+ print_usage();
+ if (logical == 0)
+ print_usage();
+ if (copy < 0)
+ print_usage();
+
+ dev = av[optind];
+
+ radix_tree_init();
+ cache_tree_init(&root_cache);
+
+ root = open_ctree(dev, 0, 1);
+ if (!root) {
+ fprintf(stderr, "Open ctree failed\n");
+ exit(1);
+ }
+
+ info_file = stdout;
+ if (output_file) {
+ if (strcmp(output_file, "-") == 0) {
+ out_fd = 1;
+ info_file = stderr;
+ } else {
+ out_fd = open(output_file, O_RDWR | O_CREAT, 0600);
+ if (out_fd < 0)
+ goto close;
+ err = ftruncate(out_fd, 0);
+ if (err) {
+ close(out_fd);
+ goto close;
+ }
+ info_file = stdout;
+ }
+ }
+
+ if (bytes == 0)
+ bytes = root->sectorsize;
+
+ bytes = (bytes + root->sectorsize - 1) / root->sectorsize;
+ bytes *= root->sectorsize;
+
+ while (bytes > 0) {
+ eb = debug_corrupt_block(root, logical, root->sectorsize, copy);
+ if (eb && output_file) {
+ err = write(out_fd, eb->data, eb->len);
+ if (err < 0 || err != eb->len) {
+ fprintf(stderr, "output file write failed\n");
+ goto out_close_fd;
+ }
+ }
+ free_extent_buffer(eb);
+ logical += root->sectorsize;
+ bytes -= root->sectorsize;
+ }
+
+out_close_fd:
+ if (output_file && out_fd != 1)
+ close(out_fd);
+close:
+ return ret;
+}