u64 bytenr, u64 num_bytes);
int btrfs_exclude_logged_extents(struct extent_buffer *eb);
int btrfs_cross_ref_exist(struct btrfs_root *root,
- u64 objectid, u64 offset, u64 bytenr);
+ u64 objectid, u64 offset, u64 bytenr, bool strict);
struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 parent, u64 root_objectid,
u64 start, u64 len);
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
- u64 *ram_bytes);
+ u64 *ram_bytes, bool strict);
void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode);
static noinline int check_committed_ref(struct btrfs_root *root,
struct btrfs_path *path,
- u64 objectid, u64 offset, u64 bytenr)
+ u64 objectid, u64 offset, u64 bytenr,
+ bool strict)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *extent_root = fs_info->extent_root;
btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY))
goto out;
- /* If extent created before last snapshot => it's definitely shared */
- if (btrfs_extent_generation(leaf, ei) <=
- btrfs_root_last_snapshot(&root->root_item))
+ /*
+ * If extent created before last snapshot => it's shared unless the
+ * snapshot has been deleted. Use the heuristic if strict is false.
+ */
+ if (!strict &&
+ (btrfs_extent_generation(leaf, ei) <=
+ btrfs_root_last_snapshot(&root->root_item)))
goto out;
iref = (struct btrfs_extent_inline_ref *)(ei + 1);
}
int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset,
- u64 bytenr)
+ u64 bytenr, bool strict)
{
struct btrfs_path *path;
int ret;
do {
ret = check_committed_ref(root, path, objectid,
- offset, bytenr);
+ offset, bytenr, strict);
if (ret && ret != -ENOENT)
goto out;
goto out_check;
ret = btrfs_cross_ref_exist(root, ino,
found_key.offset -
- extent_offset, disk_bytenr);
+ extent_offset, disk_bytenr, false);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* @orig_start: (optional) Return the original file offset of the file extent
* @orig_len: (optional) Return the original on-disk length of the file extent
* @ram_bytes: (optional) Return the ram_bytes of the file extent
+ * @strict: if true, omit optimizations that might force us into unnecessary
+ * cow. e.g., don't trust generation number.
*
* This function will flush ordered extents in the range to ensure proper
* nocow checks for (nowait == false) case.
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
- u64 *ram_bytes)
+ u64 *ram_bytes, bool strict)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path;
* Do the same check as in btrfs_cross_ref_exist but without the
* unnecessary search.
*/
- if (btrfs_file_extent_generation(leaf, fi) <=
- btrfs_root_last_snapshot(&root->root_item))
+ if (!strict &&
+ (btrfs_file_extent_generation(leaf, fi) <=
+ btrfs_root_last_snapshot(&root->root_item)))
goto out;
backref_offset = btrfs_file_extent_offset(leaf, fi);
*/
ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
- key.offset - backref_offset, disk_bytenr);
+ key.offset - backref_offset, disk_bytenr,
+ strict);
if (ret) {
ret = 0;
goto out;
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
- &orig_block_len, &ram_bytes) == 1 &&
+ &orig_block_len, &ram_bytes, false) == 1 &&
btrfs_inc_nocow_writers(fs_info, block_start)) {
struct extent_map *em2;
free_extent_map(em);
em = NULL;
- ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL);
+ ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, true);
if (ret < 0) {
goto out;
} else if (ret) {