btrfs: refactor btrfs_drop_extents() to make it easier to extend
There are many arguments for __btrfs_drop_extents() and its wrapper
btrfs_drop_extents(), which makes it hard to add more arguments to it and
requires changing every caller. I have added a couple myself back in 2014
commit 1acae57b161e ("Btrfs: faster file extent item replace operations")
and therefore know firsthand that it is a bit cumbersome to add additional
arguments to these functions.
Since I will need to add more arguments in a subsequent bug fix, this
change is preparatory work and adds a data structure that holds all the
arguments, for both input and output, that are passed to this function,
with some comments in the structure's definition mentioning what each
field is and how it relates to other fields.
Callers of this function need only to zero out the content of the
structure and setup only the fields they need. This also removes the
need to have both __btrfs_drop_extents() and btrfs_drop_extents(), so
now we have a single function named btrfs_drop_extents() that takes a
pointer to this new data structure (struct btrfs_drop_extents_args).
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 97b5b18..1648b6b 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -678,13 +678,9 @@ void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
* 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 btrfs_root *root, struct btrfs_inode *inode,
- struct btrfs_path *path, u64 start, u64 end,
- u64 *drop_end, int drop_cache,
- int replace_extent,
- u32 extent_item_size,
- int *key_inserted)
+int btrfs_drop_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_inode *inode,
+ struct btrfs_drop_extents_args *args)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *leaf;
@@ -694,12 +690,12 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
struct btrfs_key new_key;
struct inode *vfs_inode = &inode->vfs_inode;
u64 ino = btrfs_ino(inode);
- u64 search_start = start;
+ u64 search_start = args->start;
u64 disk_bytenr = 0;
u64 num_bytes = 0;
u64 extent_offset = 0;
u64 extent_end = 0;
- u64 last_end = start;
+ u64 last_end = args->start;
int del_nr = 0;
int del_slot = 0;
int extent_type;
@@ -709,11 +705,25 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
int update_refs;
int found = 0;
int leafs_visited = 0;
+ struct btrfs_path *path = args->path;
- if (drop_cache)
- btrfs_drop_extent_cache(inode, start, end - 1, 0);
+ args->extent_inserted = false;
- if (start >= inode->disk_i_size && !replace_extent)
+ /* Must always have a path if ->replace_extent is true */
+ ASSERT(!(args->replace_extent && !args->path));
+
+ if (!path) {
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ if (args->drop_cache)
+ btrfs_drop_extent_cache(inode, args->start, args->end - 1, 0);
+
+ if (args->start >= inode->disk_i_size && !args->replace_extent)
modify_tree = 0;
update_refs = (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
@@ -724,7 +734,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
search_start, modify_tree);
if (ret < 0)
break;
- if (ret > 0 && path->slots[0] > 0 && search_start == start) {
+ if (ret > 0 && path->slots[0] > 0 && search_start == args->start) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
if (key.objectid == ino &&
@@ -759,7 +769,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
path->slots[0]++;
goto next_slot;
}
- if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
+ if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end)
break;
fi = btrfs_item_ptr(leaf, path->slots[0],
@@ -801,7 +811,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
}
found = 1;
- search_start = max(key.offset, start);
+ search_start = max(key.offset, args->start);
if (recow || !modify_tree) {
modify_tree = -1;
btrfs_release_path(path);
@@ -812,7 +822,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* | - range to drop - |
* | -------- extent -------- |
*/
- if (start > key.offset && end < extent_end) {
+ if (args->start > key.offset && args->end < extent_end) {
BUG_ON(del_nr > 0);
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
ret = -EOPNOTSUPP;
@@ -820,7 +830,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
}
memcpy(&new_key, &key, sizeof(new_key));
- new_key.offset = start;
+ new_key.offset = args->start;
ret = btrfs_duplicate_item(trans, root, path,
&new_key);
if (ret == -EAGAIN) {
@@ -834,15 +844,15 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
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);
+ args->start - key.offset);
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
- extent_offset += start - key.offset;
+ extent_offset += args->start - key.offset;
btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi,
- extent_end - start);
+ extent_end - args->start);
btrfs_mark_buffer_dirty(leaf);
if (update_refs && disk_bytenr > 0) {
@@ -852,11 +862,11 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
btrfs_init_data_ref(&ref,
root->root_key.objectid,
new_key.objectid,
- start - extent_offset);
+ args->start - extent_offset);
ret = btrfs_inc_extent_ref(trans, &ref);
BUG_ON(ret); /* -ENOMEM */
}
- key.offset = start;
+ key.offset = args->start;
}
/*
* From here on out we will have actually dropped something, so
@@ -868,23 +878,24 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* | ---- range to drop ----- |
* | -------- extent -------- |
*/
- if (start <= key.offset && end < extent_end) {
+ if (args->start <= key.offset && args->end < extent_end) {
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
ret = -EOPNOTSUPP;
break;
}
memcpy(&new_key, &key, sizeof(new_key));
- new_key.offset = end;
+ new_key.offset = args->end;
btrfs_set_item_key_safe(fs_info, path, &new_key);
- extent_offset += end - key.offset;
+ extent_offset += args->end - key.offset;
btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi,
- extent_end - end);
+ extent_end - args->end);
btrfs_mark_buffer_dirty(leaf);
if (update_refs && disk_bytenr > 0)
- inode_sub_bytes(vfs_inode, end - key.offset);
+ inode_sub_bytes(vfs_inode,
+ args->end - key.offset);
break;
}
@@ -893,7 +904,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* | ---- range to drop ----- |
* | -------- extent -------- |
*/
- if (start > key.offset && end >= extent_end) {
+ if (args->start > key.offset && args->end >= extent_end) {
BUG_ON(del_nr > 0);
if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
ret = -EOPNOTSUPP;
@@ -901,11 +912,12 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
}
btrfs_set_file_extent_num_bytes(leaf, fi,
- start - key.offset);
+ args->start - key.offset);
btrfs_mark_buffer_dirty(leaf);
if (update_refs && disk_bytenr > 0)
- inode_sub_bytes(vfs_inode, extent_end - start);
- if (end == extent_end)
+ inode_sub_bytes(vfs_inode,
+ extent_end - args->start);
+ if (args->end == extent_end)
break;
path->slots[0]++;
@@ -916,7 +928,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* | ---- range to drop ----- |
* | ------ extent ------ |
*/
- if (start <= key.offset && end >= extent_end) {
+ if (args->start <= key.offset && args->end >= extent_end) {
delete_extent_item:
if (del_nr == 0) {
del_slot = path->slots[0];
@@ -946,7 +958,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
extent_end - key.offset);
}
- if (end == extent_end)
+ if (args->end == extent_end)
break;
if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
@@ -976,7 +988,7 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* Set path->slots[0] to first slot, so that after the delete
* if items are move off from our leaf to its immediate left or
* right neighbor leafs, we end up with a correct and adjusted
- * path->slots[0] for our insertion (if replace_extent != 0).
+ * path->slots[0] for our insertion (if args->replace_extent).
*/
path->slots[0] = del_slot;
ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
@@ -990,14 +1002,14 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
* which case it unlocked our path, so check path->locks[0] matches a
* write lock.
*/
- if (!ret && replace_extent && leafs_visited == 1 &&
+ if (!ret && args->replace_extent && leafs_visited == 1 &&
path->locks[0] == BTRFS_WRITE_LOCK &&
btrfs_leaf_free_space(leaf) >=
- sizeof(struct btrfs_item) + extent_item_size) {
+ sizeof(struct btrfs_item) + args->extent_item_size) {
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
- key.offset = start;
+ key.offset = args->start;
if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
struct btrfs_key slot_key;
@@ -1005,30 +1017,18 @@ int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
path->slots[0]++;
}
- setup_items_for_insert(root, path, &key, &extent_item_size, 1);
- *key_inserted = 1;
+ setup_items_for_insert(root, path, &key,
+ &args->extent_item_size, 1);
+ args->extent_inserted = true;
}
- if (!replace_extent || !(*key_inserted))
+ if (!args->path)
+ btrfs_free_path(path);
+ else if (!args->extent_inserted)
btrfs_release_path(path);
- if (drop_end)
- *drop_end = found ? min(end, last_end) : end;
- return ret;
-}
+out:
+ args->drop_end = found ? min(args->end, last_end) : args->end;
-int btrfs_drop_extents(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, struct inode *inode, u64 start,
- u64 end, int drop_cache)
-{
- struct btrfs_path *path;
- int ret;
-
- path = btrfs_alloc_path();
- if (!path)
- return -ENOMEM;
- ret = __btrfs_drop_extents(trans, root, BTRFS_I(inode), path, start,
- end, NULL, drop_cache, 0, 0, NULL);
- btrfs_free_path(path);
return ret;
}
@@ -2607,6 +2607,7 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
struct btrfs_replace_extent_info *extent_info,
struct btrfs_trans_handle **trans_out)
{
+ struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
@@ -2615,7 +2616,6 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
struct btrfs_block_rsv *rsv;
unsigned int rsv_count;
u64 cur_offset;
- u64 drop_end;
u64 len = end - start;
int ret = 0;
@@ -2654,10 +2654,12 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
trans->block_rsv = rsv;
cur_offset = start;
+ drop_args.path = path;
+ drop_args.end = end + 1;
+ drop_args.drop_cache = true;
while (cur_offset < end) {
- ret = __btrfs_drop_extents(trans, root, BTRFS_I(inode), path,
- cur_offset, end + 1, &drop_end,
- 1, 0, 0, NULL);
+ drop_args.start = cur_offset;
+ ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
if (ret != -ENOSPC) {
/*
* When cloning we want to avoid transaction aborts when
@@ -2674,10 +2676,10 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
trans->block_rsv = &fs_info->trans_block_rsv;
- if (!extent_info && cur_offset < drop_end &&
+ if (!extent_info && cur_offset < drop_args.drop_end &&
cur_offset < ino_size) {
ret = fill_holes(trans, BTRFS_I(inode), path,
- cur_offset, drop_end);
+ cur_offset, drop_args.drop_end);
if (ret) {
/*
* If we failed then we didn't insert our hole
@@ -2688,7 +2690,7 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
btrfs_abort_transaction(trans, ret);
break;
}
- } else if (!extent_info && cur_offset < drop_end) {
+ } else if (!extent_info && cur_offset < drop_args.drop_end) {
/*
* We are past the i_size here, but since we didn't
* insert holes we need to clear the mapped area so we
@@ -2696,7 +2698,8 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
* file extent is inserted here.
*/
ret = btrfs_inode_clear_file_extent_range(BTRFS_I(inode),
- cur_offset, drop_end - cur_offset);
+ cur_offset,
+ drop_args.drop_end - cur_offset);
if (ret) {
/*
* We couldn't clear our area, so we could
@@ -2708,8 +2711,10 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
}
}
- if (extent_info && drop_end > extent_info->file_offset) {
- u64 replace_len = drop_end - extent_info->file_offset;
+ if (extent_info &&
+ drop_args.drop_end > extent_info->file_offset) {
+ u64 replace_len = drop_args.drop_end -
+ extent_info->file_offset;
ret = btrfs_insert_replace_extent(trans, inode, path,
extent_info, replace_len);
@@ -2722,7 +2727,7 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
extent_info->file_offset += replace_len;
}
- cur_offset = drop_end;
+ cur_offset = drop_args.drop_end;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
@@ -2781,25 +2786,26 @@ int btrfs_replace_file_extents(struct inode *inode, struct btrfs_path *path,
* will not record the existence of the hole region
* [existing_hole_start, lockend].
*/
- if (drop_end <= end)
- drop_end = end + 1;
+ if (drop_args.drop_end <= end)
+ drop_args.drop_end = end + 1;
/*
* Don't insert file hole extent item if it's for a range beyond eof
* (because it's useless) or if it represents a 0 bytes range (when
* cur_offset == drop_end).
*/
- if (!extent_info && cur_offset < ino_size && cur_offset < drop_end) {
+ if (!extent_info && cur_offset < ino_size &&
+ cur_offset < drop_args.drop_end) {
ret = fill_holes(trans, BTRFS_I(inode), path,
- cur_offset, drop_end);
+ cur_offset, drop_args.drop_end);
if (ret) {
/* Same comment as above. */
btrfs_abort_transaction(trans, ret);
goto out_trans;
}
- } else if (!extent_info && cur_offset < drop_end) {
+ } else if (!extent_info && cur_offset < drop_args.drop_end) {
/* See the comment in the loop above for the reasoning here. */
ret = btrfs_inode_clear_file_extent_range(BTRFS_I(inode),
- cur_offset, drop_end - cur_offset);
+ cur_offset, drop_args.drop_end - cur_offset);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_trans;