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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>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
master
Josef Bacik 2013-09-09 16:41:57 -04:00 committed by Chris Mason
parent ce5a3ef3c0
commit d02aeeaae0
1 changed files with 108 additions and 9 deletions
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117
btrfs-corrupt-block.c
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@ -101,6 +101,8 @@ static void print_usage(void)
fprintf(stderr, "\t-U The whole chunk tree 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);
}
@ -290,20 +292,41 @@ 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;
@ -346,10 +369,7 @@ 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:
@ -362,6 +382,60 @@ 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' },
@ -373,6 +447,7 @@ static struct option long_options[] = {
{ "chunk-record", 0, NULL, 'u' },
{ "chunk-tree", 0, NULL, 'U' },
{ "inode", 1, NULL, 'i'},
{ "file-extent", 1, NULL, 'x'},
{ "field", 1, NULL, 'f'},
{ 0, 0, 0, 0}
};
@ -535,6 +610,7 @@ int main(int ac, char **av)
int chunk_rec = 0;
int chunk_tree = 0;
u64 inode = 0;
u64 file_extent = (u64)-1;
char field[FIELD_BUF_LEN];
field[0] = '\0';
@ -542,7 +618,7 @@ int main(int ac, char **av)
while(1) {
int c;
c = getopt_long(ac, av, "l:c:b:eEkuUi:f:", long_options,
c = getopt_long(ac, av, "l:c:b:eEkuUi:f:x:", long_options,
&option_index);
if (c < 0)
break;
@ -591,6 +667,15 @@ 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();
}
@ -663,13 +748,27 @@ 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 == (u64)-1)
print_usage();