/*
* 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.
*
* inline_limit is used to tell this code which offsets in the file to keep
* if they contain inline extents.
*/
noinline int btrfs_drop_extents(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode,
u64 start, u64 end, u64 inline_limit, u64 *hint_byte)
{
u64 extent_end = 0;
u64 locked_end = end;
u64 search_start = start;
u64 leaf_start;
u64 ram_bytes = 0;
u64 orig_parent = 0;
u64 disk_bytenr = 0;
u8 compression;
u8 encryption;
u16 other_encoding = 0;
u64 root_gen;
u64 root_owner;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *extent;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_file_extent_item old;
int keep;
int slot;
int bookend;
int found_type = 0;
int found_extent;
int found_inline;
int recow;
int ret;
inline_limit = 0;
btrfs_drop_extent_cache(inode, start, end - 1, 0);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (1) {
recow = 0;
btrfs_release_path(root, path);
ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
search_start, -1);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0) {
ret = 0;
goto out;
}
path->slots[0]--;
}
next_slot:
keep = 0;
bookend = 0;
found_extent = 0;
found_inline = 0;
leaf_start = 0;
root_gen = 0;
root_owner = 0;
compression = 0;
encryption = 0;
extent = NULL;
leaf = path->nodes[0];
slot = path->slots[0];
ret = 0;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY &&
key.offset >= end) {
goto out;
}
if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
key.objectid != inode->i_ino) {
goto out;
}
if (recow) {
search_start = max(key.offset, start);
continue;
}
if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, extent);
compression = btrfs_file_extent_compression(leaf,
extent);
encryption = btrfs_file_extent_encryption(leaf,
extent);
other_encoding = btrfs_file_extent_other_encoding(leaf,
extent);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
extent_end =
btrfs_file_extent_disk_bytenr(leaf,
extent);
if (extent_end)
*hint_byte = extent_end;
extent_end = key.offset +
btrfs_file_extent_num_bytes(leaf, extent);
ram_bytes = btrfs_file_extent_ram_bytes(leaf,
extent);
found_extent = 1;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
found_inline = 1;
extent_end = key.offset +
btrfs_file_extent_inline_len(leaf, extent);
}
} else {
/*
* 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);
}
int btrfs_check_file(struct btrfs_root *root, struct inode *inode)
{
return 0;
#if 0
struct btrfs_path *path;
struct btrfs_key found_key;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *extent;
u64 last_offset = 0;
int nritems;
int slot;
int found_type;
int ret;
int err = 0;
u64 extent_end = 0;
path = btrfs_alloc_path();
ret = btrfs_lookup_file_extent(NULL, root, path, inode->i_ino,
last_offset, 0);
while (1) {
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
}
slot = path->slots[0];
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != inode->i_ino)
break;
if (found_key.type != BTRFS_EXTENT_DATA_KEY)
goto out;
if (found_key.offset < last_offset) {
WARN_ON(1);
btrfs_print_leaf(root, leaf);
printk(KERN_ERR "inode %lu found offset %llu "
"expected %llu\n", inode->i_ino,
(unsigned long long)found_key.offset,
(unsigned long long)last_offset);
err = 1;
goto out;
}
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, extent);
if (found_type == BTRFS_FILE_EXTENT_REG) {
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, extent);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
struct btrfs_item *item;
item = btrfs_item_nr(leaf, slot);
extent_end = found_key.offset +
btrfs_file_extent_inline_len(leaf, extent);
extent_end = (extent_end + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
}
last_offset = extent_end;
path->slots[0]++;
}
if (0 && last_offset < inode->i_size) {
WARN_ON(1);
btrfs_print_leaf(root, leaf);
printk(KERN_ERR "inode %lu found offset %llu size %llu\n",
inode->i_ino, (unsigned long long)last_offset,
(unsigned long long)inode->i_size);
err = 1;
}
out:
btrfs_free_path(path);
return err;
#endif
}
