struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
u32 blocksize, u64 parent_transid)
{
int ret;
struct extent_buffer *eb;
u64 best_transid = 0;
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;
while (1) {
ret = read_whole_eb(root->fs_info, eb, mirror_num);
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;
}
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 *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;
}