Josef Bacik
2013-Sep-06 18:15 UTC
[PATCH] Btrfs-progs: add ability to corrupt file extent disk bytenr
A user had a corrupt fs where one of his file extents pointed to a completely
bogus disk bytenr. This patch allows us to corrupt a file system in a similar
way in order to test btrfsck. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
---
btrfs-corrupt-block.c | 117 +++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 108 insertions(+), 9 deletions(-)
diff --git a/btrfs-corrupt-block.c b/btrfs-corrupt-block.c
index 65cebfc..dc85889 100644
--- a/btrfs-corrupt-block.c
+++ b/btrfs-corrupt-block.c
@@ -97,6 +97,8 @@ static void print_usage(void)
fprintf(stderr, "\t-E The whole extent free to be corrupted\n");
fprintf(stderr, "\t-i The inode item to corrupt (must also specify "
"the field to corrupt\n");
+ fprintf(stderr, "\t-x The file extent item to corrupt (must also "
+ "specify -i for the inode and -f for the field to corrupt)\n");
fprintf(stderr, "\t-f The field in the item to corrupt\n");
exit(1);
}
@@ -278,20 +280,41 @@ enum btrfs_inode_field {
BTRFS_INODE_FIELD_BAD,
};
-static enum btrfs_inode_field convert_field(char *field)
+enum btrfs_file_extent_field {
+ BTRFS_FILE_EXTENT_DISK_BYTENR,
+ BTRFS_FILE_EXTENT_BAD,
+};
+
+static enum btrfs_inode_field convert_inode_field(char *field)
{
if (!strncmp(field, "isize", FIELD_BUF_LEN))
return BTRFS_INODE_FIELD_ISIZE;
return BTRFS_INODE_FIELD_BAD;
}
+static enum btrfs_file_extent_field convert_file_extent_field(char *field)
+{
+ if (!strncmp(field, "disk_bytenr", FIELD_BUF_LEN))
+ return BTRFS_FILE_EXTENT_DISK_BYTENR;
+ return BTRFS_FILE_EXTENT_BAD;
+}
+
+static u64 generate_u64(u64 orig)
+{
+ u64 ret;
+ do {
+ ret = rand();
+ } while (ret == orig);
+ return ret;
+}
+
static int corrupt_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 inode, char *field)
{
struct btrfs_inode_item *ei;
struct btrfs_path *path;
struct btrfs_key key;
- enum btrfs_inode_field corrupt_field = convert_field(field);
+ enum btrfs_inode_field corrupt_field = convert_inode_field(field);
u64 bogus;
u64 orig;
int ret;
@@ -334,10 +357,7 @@ static int corrupt_inode(struct btrfs_trans_handle *trans,
switch (corrupt_field) {
case BTRFS_INODE_FIELD_ISIZE:
orig = btrfs_inode_size(path->nodes[0], ei);
- do {
- bogus = rand();
- } while (bogus == orig);
-
+ bogus = generate_u64(orig);
btrfs_set_inode_size(path->nodes[0], ei, bogus);
break;
default:
@@ -350,6 +370,60 @@ out:
return ret;
}
+static int corrupt_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 inode, u64 extent,
+ char *field)
+{
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ enum btrfs_file_extent_field corrupt_field;
+ u64 bogus;
+ u64 orig;
+ int ret = 0;
+
+ corrupt_field = convert_file_extent_field(field);
+ if (corrupt_field == BTRFS_FILE_EXTENT_BAD) {
+ fprintf(stderr, "Invalid field %s\n", field);
+ return -EINVAL;
+ }
+
+ key.objectid = inode;
+ key.type = BTRFS_EXTENT_DATA_KEY;
+ key.offset = extent;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0)
+ goto out;
+ if (ret) {
+ fprintf(stderr, "Couldn''t find extent %llu for inode
%llu\n",
+ extent, inode);
+ ret = -ENOENT;
+ goto out;
+ }
+
+ fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_file_extent_item);
+ switch (corrupt_field) {
+ case BTRFS_FILE_EXTENT_DISK_BYTENR:
+ orig = btrfs_file_extent_disk_bytenr(path->nodes[0], fi);
+ bogus = generate_u64(orig);
+ btrfs_set_file_extent_disk_bytenr(path->nodes[0], fi, bogus);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
static struct option long_options[] = {
/* { "byte-count", 1, NULL, ''b'' }, */
{ "logical", 1, NULL, ''l'' },
@@ -359,6 +433,7 @@ static struct option long_options[] = {
{ "extent-tree", 0, NULL, ''E'' },
{ "keys", 0, NULL, ''k'' },
{ "inode", 1, NULL, ''i''},
+ { "file-extent", 1, NULL, ''x''},
{ "field", 1, NULL, ''f''},
{ 0, 0, 0, 0}
};
@@ -379,6 +454,7 @@ int main(int ac, char **av)
int extent_tree = 0;
int corrupt_block_keys = 0;
u64 inode = 0;
+ u64 file_extent = (u64)-1;
char field[FIELD_BUF_LEN];
field[0] = ''\0'';
@@ -386,7 +462,7 @@ int main(int ac, char **av)
while(1) {
int c;
- c = getopt_long(ac, av, "l:c:b:eEki:f:", long_options,
+ c = getopt_long(ac, av, "l:c:b:eEki:f:x:", long_options,
&option_index);
if (c < 0)
break;
@@ -435,6 +511,15 @@ int main(int ac, char **av)
case ''f'':
strncpy(field, optarg, FIELD_BUF_LEN);
break;
+ case ''x'':
+ errno = 0;
+ file_extent = atoll(optarg);
+ if (errno) {
+ fprintf(stderr, "error converting "
+ "%d\n", errno);
+ print_usage();
+ }
+ break;
default:
print_usage();
}
@@ -476,13 +561,27 @@ int main(int ac, char **av)
if (!strlen(field))
print_usage();
- printf("corrupting inode\n");
+
trans = btrfs_start_transaction(root, 1);
- ret = corrupt_inode(trans, root, inode, field);
+ if (file_extent == (u64)-1) {
+ printf("corrupting inode\n");
+ ret = corrupt_inode(trans, root, inode, field);
+ } else {
+ printf("corrupting file extent\n");
+ ret = corrupt_file_extent(trans, root, inode,
+ file_extent, field);
+ }
btrfs_commit_transaction(trans, root);
goto out_close;
}
+ /*
+ * If we made it here and we have extent set then we didn''t specify
+ * inode and we''re screwed.
+ */
+ if (file_extent != (u64)-1)
+ print_usage();
+
if (logical == 0)
print_usage();
--
1.7.7.6
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