Btrfs-progs: make btrfs-image grab the free space cache

A lot of tree log replay bugs are because of strange space cache setups, so make
btrfs-image scrape the free space cache as well so we can better replicate what
a user is seeing if they have a tree log bug or anything related to free space
cache.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
This commit is contained in:
Josef Bacik 2013-03-19 09:43:13 -04:00 committed by David Sterba
parent 274518d7b8
commit 2881054956

View file

@ -34,7 +34,7 @@
#include "transaction.h"
#include "utils.h"
#include "version.h"
#include "volumes.h"
#define HEADER_MAGIC 0xbd5c25e27295668bULL
#define MAX_PENDING_SIZE (256 * 1024)
@ -96,6 +96,7 @@ struct metadump_struct {
int compress_level;
int done;
int data;
};
struct mdrestore_struct {
@ -409,6 +410,60 @@ out:
return err;
}
static int read_data_extent(struct metadump_struct *md,
struct async_work *async)
{
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
u64 bytes_left = async->size;
u64 logical = async->start;
u64 offset = 0;
u64 bytenr;
u64 read_len;
ssize_t done;
int fd;
int ret;
while (bytes_left) {
read_len = bytes_left;
ret = btrfs_map_block(&md->root->fs_info->mapping_tree, READ,
logical, &read_len, &multi, 0, NULL);
if (ret) {
fprintf(stderr, "Couldn't map data block %d\n", ret);
return ret;
}
device = multi->stripes[0].dev;
if (device->fd == 0) {
fprintf(stderr,
"Device we need to read from is not open\n");
free(multi);
return -EIO;
}
fd = device->fd;
bytenr = multi->stripes[0].physical;
free(multi);
read_len = min(read_len, bytes_left);
done = pread64(fd, async->buffer+offset, read_len, bytenr);
if (done < read_len) {
if (done < 0)
fprintf(stderr, "Error reading extent %d\n",
errno);
else
fprintf(stderr, "Short read\n");
return -EIO;
}
bytes_left -= done;
offset += done;
logical += done;
}
return 0;
}
static int flush_pending(struct metadump_struct *md, int done)
{
struct async_work *async = NULL;
@ -435,7 +490,17 @@ static int flush_pending(struct metadump_struct *md, int done)
offset = 0;
start = async->start;
size = async->size;
while (size > 0) {
if (md->data) {
ret = read_data_extent(md, async);
if (ret) {
free(async->buffer);
free(async);
return ret;
}
}
while (!md->data && size > 0) {
eb = read_tree_block(md->root, start, blocksize, 0);
if (!eb) {
free(async->buffer);
@ -480,10 +545,12 @@ static int flush_pending(struct metadump_struct *md, int done)
return ret;
}
static int add_metadata(u64 start, u64 size, struct metadump_struct *md)
static int add_extent(u64 start, u64 size, struct metadump_struct *md,
int data)
{
int ret;
if (md->pending_size + size > MAX_PENDING_SIZE ||
if (md->data != data ||
md->pending_size + size > MAX_PENDING_SIZE ||
md->pending_start + md->pending_size != start) {
ret = flush_pending(md, 0);
if (ret)
@ -492,6 +559,7 @@ static int add_metadata(u64 start, u64 size, struct metadump_struct *md)
}
readahead_tree_block(md->root, start, size, 0);
md->pending_size += size;
md->data = data;
return 0;
}
@ -545,7 +613,7 @@ static int copy_log_blocks(struct btrfs_root *root, struct extent_buffer *eb,
int i = 0;
int ret;
ret = add_metadata(btrfs_header_bytenr(eb), root->leafsize, metadump);
ret = add_extent(btrfs_header_bytenr(eb), root->leafsize, metadump, 0);
if (ret) {
fprintf(stderr, "Error adding metadata block\n");
return ret;
@ -610,6 +678,72 @@ static int copy_log_trees(struct btrfs_root *root,
metadump, 1);
}
static int copy_space_cache(struct btrfs_root *root,
struct metadump_struct *metadump,
struct btrfs_path *path)
{
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 bytenr, num_bytes;
int ret;
root = root->fs_info->tree_root;
key.objectid = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0) {
fprintf(stderr, "Error searching for free space inode %d\n",
ret);
return ret;
}
while (1) {
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
fprintf(stderr, "Error going to next leaf "
"%d\n", ret);
return ret;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.type != BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
continue;
}
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, fi) !=
BTRFS_FILE_EXTENT_REG) {
path->slots[0]++;
continue;
}
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
ret = add_extent(bytenr, num_bytes, metadump, 1);
if (ret) {
fprintf(stderr, "Error adding space cache blocks %d\n",
ret);
btrfs_release_path(root, path);
return ret;
}
path->slots[0]++;
}
return 0;
}
static int create_metadump(const char *input, FILE *out, int num_threads,
int compress_level)
{
@ -641,7 +775,7 @@ static int create_metadump(const char *input, FILE *out, int num_threads,
return ret;
}
ret = add_metadata(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump);
ret = add_extent(BTRFS_SUPER_INFO_OFFSET, 4096, &metadump, 0);
if (ret) {
fprintf(stderr, "Error adding metadata %d\n", ret);
err = ret;
@ -697,8 +831,8 @@ static int create_metadump(const char *input, FILE *out, int num_threads,
struct btrfs_extent_item);
if (btrfs_extent_flags(leaf, ei) &
BTRFS_EXTENT_FLAG_TREE_BLOCK) {
ret = add_metadata(bytenr, num_bytes,
&metadump);
ret = add_extent(bytenr, num_bytes, &metadump,
0);
if (ret) {
fprintf(stderr, "Error adding block "
"%d\n", ret);
@ -717,8 +851,8 @@ static int create_metadump(const char *input, FILE *out, int num_threads,
}
if (ret) {
ret = add_metadata(bytenr, num_bytes,
&metadump);
ret = add_extent(bytenr, num_bytes, &metadump,
0);
if (ret) {
fprintf(stderr, "Error adding block "
"%d\n", ret);
@ -736,9 +870,15 @@ static int create_metadump(const char *input, FILE *out, int num_threads,
bytenr += num_bytes;
}
btrfs_release_path(root, path);
ret = copy_log_trees(root, &metadump, path);
if (ret)
if (ret) {
err = ret;
goto out;
}
ret = copy_space_cache(root, &metadump, path);
out:
ret = flush_pending(&metadump, 1);
if (ret) {