static int clear_free_space_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
struct btrfs_path *path;
struct btrfs_key key;
int nr;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
key.objectid = 0;
key.type = 0;
key.offset = 0;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
nr = btrfs_header_nritems(path->nodes[0]);
if (!nr)
break;
path->slots[0] = 0;
ret = btrfs_del_items(trans, root, path, 0, nr);
if (ret)
goto out;
btrfs_release_path(path);
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
int convert_free_space_to_extents(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
struct btrfs_root *root = fs_info->free_space_root;
struct btrfs_free_space_info *info;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
unsigned long *bitmap;
u64 start, end;
/* Initialize to silence GCC. */
u64 extent_start = 0;
u64 offset;
u32 bitmap_size, flags, expected_extent_count;
int prev_bit = 0, bit, bitnr;
u32 extent_count = 0;
int done = 0, nr;
int ret;
bitmap_size = free_space_bitmap_size(block_group->key.offset,
block_group->sectorsize);
bitmap = alloc_bitmap(bitmap_size);
if (!bitmap) {
ret = -ENOMEM;
goto out;
}
start = block_group->key.objectid;
end = block_group->key.objectid + block_group->key.offset;
key.objectid = end - 1;
key.type = (u8)-1;
key.offset = (u64)-1;
while (!done) {
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
if (ret)
goto out;
leaf = path->nodes[0];
nr = 0;
path->slots[0]++;
while (path->slots[0] > 0) {
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
ASSERT(found_key.objectid == block_group->key.objectid);
ASSERT(found_key.offset == block_group->key.offset);
done = 1;
break;
} else if (found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
unsigned long ptr;
char *bitmap_cursor;
u32 bitmap_pos, data_size;
ASSERT(found_key.objectid >= start);
ASSERT(found_key.objectid < end);
ASSERT(found_key.objectid + found_key.offset <= end);
bitmap_pos = div_u64(found_key.objectid - start,
block_group->sectorsize *
BITS_PER_BYTE);
bitmap_cursor = ((char *)bitmap) + bitmap_pos;
data_size = free_space_bitmap_size(found_key.offset,
block_group->sectorsize);
ptr = btrfs_item_ptr_offset(leaf, path->slots[0] - 1);
read_extent_buffer(leaf, bitmap_cursor, ptr,
data_size);
nr++;
path->slots[0]--;
} else {
ASSERT(0);
}
}
ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
if (ret)
goto out;
btrfs_release_path(path);
}
info = search_free_space_info(trans, fs_info, block_group, path, 1);
if (IS_ERR(info)) {
ret = PTR_ERR(info);
goto out;
}
leaf = path->nodes[0];
flags = btrfs_free_space_flags(leaf, info);
flags &= ~BTRFS_FREE_SPACE_USING_BITMAPS;
btrfs_set_free_space_flags(leaf, info, flags);
expected_extent_count = btrfs_free_space_extent_count(leaf, info);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
offset = start;
bitnr = 0;
while (offset < end) {
bit = !!test_bit(bitnr, bitmap);
if (prev_bit == 0 && bit == 1) {
extent_start = offset;
} else if (prev_bit == 1 && bit == 0) {
key.objectid = extent_start;
key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
key.offset = offset - extent_start;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
if (ret)
goto out;
btrfs_release_path(path);
extent_count++;
}
prev_bit = bit;
offset += block_group->sectorsize;
bitnr++;
}
if (prev_bit == 1) {
key.objectid = extent_start;
key.type = BTRFS_FREE_SPACE_EXTENT_KEY;
key.offset = end - extent_start;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
if (ret)
goto out;
btrfs_release_path(path);
extent_count++;
}
if (extent_count != expected_extent_count) {
btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
block_group->key.objectid, extent_count,
expected_extent_count);
ASSERT(0);
ret = -EIO;
goto out;
}
ret = 0;
out:
kvfree(bitmap);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
}
int convert_free_space_to_bitmaps(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
struct btrfs_root *root = fs_info->free_space_root;
struct btrfs_free_space_info *info;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
unsigned long *bitmap;
char *bitmap_cursor;
u64 start, end;
u64 bitmap_range, i;
u32 bitmap_size, flags, expected_extent_count;
u32 extent_count = 0;
int done = 0, nr;
int ret;
bitmap_size = free_space_bitmap_size(block_group->key.offset,
block_group->sectorsize);
bitmap = alloc_bitmap(bitmap_size);
if (!bitmap) {
ret = -ENOMEM;
goto out;
}
start = block_group->key.objectid;
end = block_group->key.objectid + block_group->key.offset;
key.objectid = end - 1;
key.type = (u8)-1;
key.offset = (u64)-1;
while (!done) {
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
if (ret)
goto out;
leaf = path->nodes[0];
nr = 0;
path->slots[0]++;
while (path->slots[0] > 0) {
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
ASSERT(found_key.objectid == block_group->key.objectid);
ASSERT(found_key.offset == block_group->key.offset);
done = 1;
break;
} else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY) {
u64 first, last;
ASSERT(found_key.objectid >= start);
ASSERT(found_key.objectid < end);
ASSERT(found_key.objectid + found_key.offset <= end);
first = div_u64(found_key.objectid - start,
block_group->sectorsize);
last = div_u64(found_key.objectid + found_key.offset - start,
block_group->sectorsize);
bitmap_set(bitmap, first, last - first);
extent_count++;
nr++;
path->slots[0]--;
} else {
ASSERT(0);
}
}
ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
if (ret)
goto out;
btrfs_release_path(path);
}
info = search_free_space_info(trans, fs_info, block_group, path, 1);
if (IS_ERR(info)) {
ret = PTR_ERR(info);
goto out;
}
leaf = path->nodes[0];
flags = btrfs_free_space_flags(leaf, info);
flags |= BTRFS_FREE_SPACE_USING_BITMAPS;
btrfs_set_free_space_flags(leaf, info, flags);
expected_extent_count = btrfs_free_space_extent_count(leaf, info);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
if (extent_count != expected_extent_count) {
btrfs_err(fs_info, "incorrect extent count for %llu; counted %u, expected %u",
block_group->key.objectid, extent_count,
expected_extent_count);
ASSERT(0);
ret = -EIO;
goto out;
}
bitmap_cursor = (char *)bitmap;
bitmap_range = block_group->sectorsize * BTRFS_FREE_SPACE_BITMAP_BITS;
i = start;
while (i < end) {
unsigned long ptr;
u64 extent_size;
u32 data_size;
extent_size = min(end - i, bitmap_range);
data_size = free_space_bitmap_size(extent_size,
block_group->sectorsize);
key.objectid = i;
key.type = BTRFS_FREE_SPACE_BITMAP_KEY;
key.offset = extent_size;
ret = btrfs_insert_empty_item(trans, root, path, &key,
data_size);
if (ret)
goto out;
leaf = path->nodes[0];
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
write_extent_buffer(leaf, bitmap_cursor, ptr,
data_size);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
i += extent_size;
bitmap_cursor += data_size;
}
ret = 0;
out:
kvfree(bitmap);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
}
int remove_block_group_free_space(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_root *root = fs_info->free_space_root;
struct btrfs_path *path;
struct btrfs_key key, found_key;
struct extent_buffer *leaf;
u64 start, end;
int done = 0, nr;
int ret;
if (!btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE))
return 0;
if (block_group->needs_free_space) {
/* We never added this block group to the free space tree. */
return 0;
}
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
start = block_group->key.objectid;
end = block_group->key.objectid + block_group->key.offset;
key.objectid = end - 1;
key.type = (u8)-1;
key.offset = (u64)-1;
while (!done) {
ret = btrfs_search_prev_slot(trans, root, &key, path, -1, 1);
if (ret)
goto out;
leaf = path->nodes[0];
nr = 0;
path->slots[0]++;
while (path->slots[0] > 0) {
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0] - 1);
if (found_key.type == BTRFS_FREE_SPACE_INFO_KEY) {
ASSERT(found_key.objectid == block_group->key.objectid);
ASSERT(found_key.offset == block_group->key.offset);
done = 1;
nr++;
path->slots[0]--;
break;
} else if (found_key.type == BTRFS_FREE_SPACE_EXTENT_KEY ||
found_key.type == BTRFS_FREE_SPACE_BITMAP_KEY) {
ASSERT(found_key.objectid >= start);
ASSERT(found_key.objectid < end);
ASSERT(found_key.objectid + found_key.offset <= end);
nr++;
path->slots[0]--;
} else {
ASSERT(0);
}
}
ret = btrfs_del_items(trans, root, path, path->slots[0], nr);
if (ret)
goto out;
btrfs_release_path(path);
}
ret = 0;
out:
btrfs_free_path(path);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
}
/*
* this is very complex, but the basic idea is to drop all extents
* in the range start - end. hint_block is filled in with a block number
* that would be a good hint to the block allocator for this file.
*
* If an extent intersects the range but is not entirely inside the range
* it is either truncated or split. Anything entirely inside the range
* is deleted from the tree.
*/
int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
u64 start, u64 end, u64 *hint_byte, int drop_cache)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key new_key;
u64 search_start = start;
u64 disk_bytenr = 0;
u64 num_bytes = 0;
u64 extent_offset = 0;
u64 extent_end = 0;
int del_nr = 0;
int del_slot = 0;
int extent_type;
int recow;
int ret;
if (drop_cache)
btrfs_drop_extent_cache(inode, start, end - 1, 0);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (1) {
recow = 0;
ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
search_start, -1);
if (ret < 0)
break;
if (ret > 0 && path->slots[0] > 0 && search_start == start) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
if (key.objectid == inode->i_ino &&
key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
ret = 0;
next_slot:
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
BUG_ON(del_nr > 0);
ret = btrfs_next_leaf(root, path);
if (ret < 0)
break;
if (ret > 0) {
ret = 0;
break;
}
leaf = path->nodes[0];
recow = 1;
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid > inode->i_ino ||
key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
break;
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = key.offset +
btrfs_file_extent_inline_len(leaf, fi);
} else {
WARN_ON(1);
extent_end = search_start;
}
if (extent_end <= search_start) {
path->slots[0]++;
goto next_slot;
}
search_start = max(key.offset, start);
if (recow) {
btrfs_release_path(root, path);
continue;
}
/*
* | - range to drop - |
* | -------- extent -------- |
*/
if (start > key.offset && end < extent_end) {
BUG_ON(del_nr > 0);
BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
memcpy(&new_key, &key, sizeof(new_key));
new_key.offset = start;
ret = btrfs_duplicate_item(trans, root, path,
&new_key);
if (ret == -EAGAIN) {
btrfs_release_path(root, path);
continue;
}
if (ret < 0)
break;
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
struct btrfs_file_extent_item);
btrfs_set_file_extent_num_bytes(leaf, fi,
start - key.offset);
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_offset += start - key.offset;
btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_end - start);
btrfs_mark_buffer_dirty(leaf);
if (disk_bytenr > 0) {
ret = btrfs_inc_extent_ref(trans, root,
disk_bytenr, num_bytes, 0,
root->root_key.objectid,
new_key.objectid,
start - extent_offset);
BUG_ON(ret);
*hint_byte = disk_bytenr;
}
key.offset = start;
}
/*
* | ---- range to drop ----- |
* | -------- extent -------- |
*/
if (start <= key.offset && end < extent_end) {
BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
memcpy(&new_key, &key, sizeof(new_key));
new_key.offset = end;
btrfs_set_item_key_safe(trans, root, path, &new_key);
extent_offset += end - key.offset;
btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_end - end);
btrfs_mark_buffer_dirty(leaf);
if (disk_bytenr > 0) {
inode_sub_bytes(inode, end - key.offset);
*hint_byte = disk_bytenr;
}
break;
}
search_start = extent_end;
/*
* | ---- range to drop ----- |
* | -------- extent -------- |
*/
if (start > key.offset && end >= extent_end) {
BUG_ON(del_nr > 0);
BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_num_bytes(leaf, fi,
start - key.offset);
btrfs_mark_buffer_dirty(leaf);
if (disk_bytenr > 0) {
inode_sub_bytes(inode, extent_end - start);
*hint_byte = disk_bytenr;
}
if (end == extent_end)
break;
path->slots[0]++;
goto next_slot;
}
/*
* | ---- range to drop ----- |
* | ------ extent ------ |
*/
if (start <= key.offset && end >= extent_end) {
if (del_nr == 0) {
del_slot = path->slots[0];
del_nr = 1;
} else {
BUG_ON(del_slot + del_nr != path->slots[0]);
del_nr++;
}
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
inode_sub_bytes(inode,
extent_end - key.offset);
extent_end = ALIGN(extent_end,
root->sectorsize);
} else if (disk_bytenr > 0) {
ret = btrfs_free_extent(trans, root,
disk_bytenr, num_bytes, 0,
root->root_key.objectid,
key.objectid, key.offset -
extent_offset);
BUG_ON(ret);
inode_sub_bytes(inode,
extent_end - key.offset);
*hint_byte = disk_bytenr;
}
if (end == extent_end)
break;
if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
path->slots[0]++;
goto next_slot;
}
ret = btrfs_del_items(trans, root, path, del_slot,
del_nr);
BUG_ON(ret);
del_nr = 0;
del_slot = 0;
btrfs_release_path(root, path);
continue;
}
BUG_ON(1);
}
