int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
u64 parent_transid)
{
int ret;
struct extent_buffer *eb;
u64 length;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
eb = btrfs_find_tree_block(root, bytenr, blocksize);
if (eb && btrfs_buffer_uptodate(eb, parent_transid)) {
free_extent_buffer(eb);
return 0;
}
length = blocksize;
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
bytenr, &length, &multi, 0, NULL);
BUG_ON(ret);
device = multi->stripes[0].dev;
device->total_ios++;
blocksize = min(blocksize, (u32)(64 * 1024));
readahead(device->fd, multi->stripes[0].physical, blocksize);
kfree(multi);
return 0;
}
int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct extent_buffer *eb)
{
int ret;
int dev_nr;
u64 length;
struct btrfs_multi_bio *multi = NULL;
if (check_tree_block(root, eb))
BUG();
if (!btrfs_buffer_uptodate(eb, trans->transid))
BUG();
btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
csum_tree_block(root, eb, 0);
dev_nr = 0;
length = eb->len;
ret = btrfs_map_block(&root->fs_info->mapping_tree, WRITE,
eb->start, &length, &multi, 0);
while(dev_nr < multi->num_stripes) {
BUG_ON(ret);
eb->fd = multi->stripes[dev_nr].dev->fd;
eb->dev_bytenr = multi->stripes[dev_nr].physical;
multi->stripes[dev_nr].dev->total_ios++;
dev_nr++;
ret = write_extent_to_disk(eb);
BUG_ON(ret);
}
kfree(multi);
return 0;
}
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid)
{
int ret;
int dev_nr;
struct extent_buffer *eb;
u64 length;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int mirror_num = 0;
int num_copies;
eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!eb)
return NULL;
if (btrfs_buffer_uptodate(eb, parent_transid))
return eb;
dev_nr = 0;
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;
kfree(multi);
ret = read_extent_from_disk(eb);
if (ret == 0 && check_tree_block(root, eb) == 0 &&
csum_tree_block(root, eb, 1) == 0 &&
verify_parent_transid(eb->tree, eb, parent_transid) == 0) {
btrfs_set_buffer_uptodate(eb);
return eb;
}
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;
}
}
free_extent_buffer(eb);
return NULL;
}
struct extent_buffer *debug_read_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);
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 int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirror)
{
unsigned long offset = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int ret = 0;
u64 read_len;
unsigned long bytes_left = eb->len;
while (bytes_left) {
read_len = bytes_left;
ret = btrfs_map_block(&info->mapping_tree, READ,
eb->start + offset, &read_len, &multi,
mirror, NULL);
if (ret) {
printk("Couldn't map the block %Lu\n", eb->start + offset);
kfree(multi);
return -EIO;
}
device = multi->stripes[0].dev;
if (device->fd == 0) {
kfree(multi);
return -EIO;
}
eb->fd = device->fd;
device->total_ios++;
eb->dev_bytenr = multi->stripes[0].physical;
kfree(multi);
multi = NULL;
if (read_len > bytes_left)
read_len = bytes_left;
ret = read_extent_from_disk(eb, offset, read_len);
if (ret)
return -EIO;
offset += read_len;
bytes_left -= read_len;
}
return 0;
}
static int __print_mapping_info(struct btrfs_fs_info *fs_info, u64 logical,
u64 len, int mirror_num)
{
struct btrfs_multi_bio *multi = NULL;
u64 cur_offset = 0;
u64 cur_len;
int ret = 0;
while (cur_offset < len) {
struct btrfs_device *device;
int i;
cur_len = len - cur_offset;
ret = btrfs_map_block(&fs_info->mapping_tree, READ,
logical + cur_offset, &cur_len,
&multi, mirror_num, NULL);
if (ret) {
fprintf(info_file,
"Error: fails to map mirror%d logical %llu: %s\n",
mirror_num, logical, strerror(-ret));
return ret;
}
for (i = 0; i < multi->num_stripes; i++) {
device = multi->stripes[i].dev;
fprintf(info_file,
"mirror %d logical %Lu physical %Lu device %s\n",
mirror_num, logical + cur_offset,
multi->stripes[0].physical,
device->name);
}
kfree(multi);
multi = NULL;
cur_offset += cur_len;
}
return ret;
}
struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid)
{
int ret;
struct extent_buffer *eb;
u64 length;
u64 best_transid = 0;
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
int mirror_num = 0;
int good_mirror = 0;
int num_copies;
int ignore = 0;
eb = btrfs_find_create_tree_block(root, bytenr, blocksize);
if (!eb)
return NULL;
if (btrfs_buffer_uptodate(eb, parent_transid))
return eb;
length = blocksize;
while (1) {
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
eb->start, &length, &multi, mirror_num);
if (ret) {
printk("Couldn't map the block %Lu\n", bytenr);
break;
}
device = multi->stripes[0].dev;
eb->fd = device->fd;
device->total_ios++;
eb->dev_bytenr = multi->stripes[0].physical;
kfree(multi);
ret = read_extent_from_disk(eb);
if (ret == 0 && check_tree_block(root, eb) == 0 &&
csum_tree_block(root, eb, 1) == 0 &&
verify_parent_transid(eb->tree, eb, parent_transid, ignore)
== 0) {
btrfs_set_buffer_uptodate(eb);
return eb;
}
if (ignore) {
if (check_tree_block(root, eb))
printk("read block failed check_tree_block\n");
else
printk("Csum didn't match\n");
break;
}
num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
eb->start, eb->len);
if (num_copies == 1) {
ignore = 1;
continue;
}
if (btrfs_header_generation(eb) > best_transid) {
best_transid = btrfs_header_generation(eb);
good_mirror = mirror_num;
}
mirror_num++;
if (mirror_num > num_copies) {
mirror_num = good_mirror;
ignore = 1;
continue;
}
}
free_extent_buffer(eb);
return NULL;
}
static int copy_one_extent(struct btrfs_root *root, int fd,
struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi, u64 pos)
{
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
char *inbuf, *outbuf = NULL;
ssize_t done, total = 0;
u64 bytenr;
u64 ram_size;
u64 disk_size;
u64 num_bytes;
u64 length;
u64 size_left;
u64 dev_bytenr;
u64 offset;
u64 count = 0;
int compress;
int ret;
int dev_fd;
int mirror_num = 1;
int num_copies;
compress = btrfs_file_extent_compression(leaf, fi);
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
disk_size = btrfs_file_extent_disk_num_bytes(leaf, fi);
ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
offset = btrfs_file_extent_offset(leaf, fi);
num_bytes = btrfs_file_extent_num_bytes(leaf, fi);
size_left = disk_size;
if (compress == BTRFS_COMPRESS_NONE)
bytenr += offset;
if (verbose && offset)
printf("offset is %Lu\n", offset);
/* we found a hole */
if (disk_size == 0)
return 0;
inbuf = malloc(size_left);
if (!inbuf) {
fprintf(stderr, "No memory\n");
return -ENOMEM;
}
if (compress != BTRFS_COMPRESS_NONE) {
outbuf = calloc(1, ram_size);
if (!outbuf) {
fprintf(stderr, "No memory\n");
free(inbuf);
return -ENOMEM;
}
}
again:
length = size_left;
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
bytenr, &length, &multi, mirror_num, NULL);
if (ret) {
fprintf(stderr, "Error mapping block %d\n", ret);
goto out;
}
device = multi->stripes[0].dev;
dev_fd = device->fd;
device->total_ios++;
dev_bytenr = multi->stripes[0].physical;
kfree(multi);
if (size_left < length)
length = size_left;
done = pread(dev_fd, inbuf+count, length, dev_bytenr);
/* Need both checks, or we miss negative values due to u64 conversion */
if (done < 0 || done < length) {
num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
bytenr, length);
mirror_num++;
/* mirror_num is 1-indexed, so num_copies is a valid mirror. */
if (mirror_num > num_copies) {
ret = -1;
fprintf(stderr, "Exhausted mirrors trying to read\n");
goto out;
}
fprintf(stderr, "Trying another mirror\n");
goto again;
}
mirror_num = 1;
size_left -= length;
count += length;
bytenr += length;
if (size_left)
goto again;
if (compress == BTRFS_COMPRESS_NONE) {
while (total < num_bytes) {
done = pwrite(fd, inbuf+total, num_bytes-total,
pos+total);
if (done < 0) {
ret = -1;
fprintf(stderr, "Error writing: %d %s\n", errno, strerror(errno));
goto out;
}
total += done;
}
ret = 0;
goto out;
}
ret = decompress(inbuf, outbuf, disk_size, &ram_size, compress);
if (ret) {
num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
bytenr, length);
mirror_num++;
if (mirror_num >= num_copies) {
ret = -1;
goto out;
}
fprintf(stderr, "Trying another mirror\n");
goto again;
}
while (total < num_bytes) {
done = pwrite(fd, outbuf + offset + total,
num_bytes - total,
pos + total);
if (done < 0) {
ret = -1;
goto out;
}
total += done;
}
out:
free(inbuf);
free(outbuf);
return ret;
}
static int copy_one_extent(struct btrfs_root *root, int fd,
struct extent_buffer *leaf,
struct btrfs_file_extent_item *fi, u64 pos)
{
struct btrfs_multi_bio *multi = NULL;
struct btrfs_device *device;
char *inbuf, *outbuf = NULL;
ssize_t done, total = 0;
u64 bytenr;
u64 ram_size;
u64 disk_size;
u64 length;
u64 size_left;
u64 dev_bytenr;
u64 count = 0;
int compress;
int ret;
int dev_fd;
compress = btrfs_file_extent_compression(leaf, fi);
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
disk_size = btrfs_file_extent_disk_num_bytes(leaf, fi);
ram_size = btrfs_file_extent_ram_bytes(leaf, fi);
size_left = disk_size;
/* we found a hole */
if (disk_size == 0)
return 0;
inbuf = malloc(disk_size);
if (!inbuf) {
fprintf(stderr, "No memory\n");
return -1;
}
if (compress != BTRFS_COMPRESS_NONE) {
outbuf = malloc(ram_size);
if (!outbuf) {
fprintf(stderr, "No memory\n");
free(inbuf);
return -1;
}
}
again:
length = size_left;
ret = btrfs_map_block(&root->fs_info->mapping_tree, READ,
bytenr, &length, &multi, 0);
if (ret) {
free(inbuf);
free(outbuf);
fprintf(stderr, "Error mapping block %d\n", ret);
return ret;
}
device = multi->stripes[0].dev;
dev_fd = device->fd;
device->total_ios++;
dev_bytenr = multi->stripes[0].physical;
kfree(multi);
if (size_left < length)
length = size_left;
size_left -= length;
done = pread(dev_fd, inbuf+count, length, dev_bytenr);
if (done < length) {
free(inbuf);
free(outbuf);
fprintf(stderr, "Short read %d\n", errno);
return -1;
}
count += length;
bytenr += length;
if (size_left)
goto again;
if (compress == BTRFS_COMPRESS_NONE) {
while (total < ram_size) {
done = pwrite(fd, inbuf+total, ram_size-total,
pos+total);
if (done < 0) {
free(inbuf);
fprintf(stderr, "Error writing: %d %s\n", errno, strerror(errno));
return -1;
}
total += done;
}
free(inbuf);
return 0;
}
ret = decompress(inbuf, outbuf, disk_size, ram_size);
free(inbuf);
if (ret) {
free(outbuf);
return ret;
}
while (total < ram_size) {
done = pwrite(fd, outbuf+total, ram_size-total, pos+total);
if (done < 0) {
free(outbuf);
fprintf(stderr, "Error writing: %d %s\n", errno, strerror(errno));
return -1;
}
total += done;
}
free(outbuf);
return 0;
}