AcoSail/kernel_optimize_test
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btrfs: ctree: Reduce one indent level for btrfs_search_slot()

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In btrfs_search_slot(), we something like:

	if (level != 0) {
		/* Do search inside tree nodes*/
	} else {
		/* Do search inside tree leaves */
		goto done;
	}

This caused extra indent for tree node search code.  Change it to
something like:

	if (level == 0) {
		/* Do search inside tree leaves */
		goto done'
	}
	/* Do search inside tree nodes */

So we have more space to maneuver our code, this is especially useful as
the tree nodes search code is more complex than the leaves search code.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2019-09-10 15:40:17 +08:00 committed by David Sterba
parent 71bf92a9b8
commit f624d97608
1 changed files with 64 additions and 67 deletions
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131
fs/btrfs/ctree.c
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@ -2785,6 +2785,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
}
while (b) {
int dec = 0;
level = btrfs_header_level(b);
/*
@ -2861,73 +2863,7 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
if (ret < 0)
goto done;
if (level != 0) {
int dec = 0;
if (ret && slot > 0) {
dec = 1;
slot -= 1;
}
p->slots[level] = slot;
err = setup_nodes_for_search(trans, root, p, b, level,
ins_len, &write_lock_level);
if (err == -EAGAIN)
goto again;
if (err) {
ret = err;
goto done;
}
b = p->nodes[level];
slot = p->slots[level];
/*
* slot 0 is special, if we change the key
* we have to update the parent pointer
* which means we must have a write lock
* on the parent
*/
if (slot == 0 && ins_len &&
write_lock_level < level + 1) {
write_lock_level = level + 1;
btrfs_release_path(p);
goto again;
}
unlock_up(p, level, lowest_unlock,
min_write_lock_level, &write_lock_level);
if (level == lowest_level) {
if (dec)
p->slots[level]++;
goto done;
}
err = read_block_for_search(root, p, &b, level,
slot, key);
if (err == -EAGAIN)
goto again;
if (err) {
ret = err;
goto done;
}
if (!p->skip_locking) {
level = btrfs_header_level(b);
if (level <= write_lock_level) {
if (!btrfs_try_tree_write_lock(b)) {
btrfs_set_path_blocking(p);
btrfs_tree_lock(b);
}
p->locks[level] = BTRFS_WRITE_LOCK;
} else {
if (!btrfs_tree_read_lock_atomic(b)) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
}
p->locks[level] = BTRFS_READ_LOCK;
}
p->nodes[level] = b;
}
} else {
if (level == 0) {
p->slots[level] = slot;
if (ins_len > 0 &&
btrfs_leaf_free_space(b) < ins_len) {
@ -2952,6 +2888,67 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
min_write_lock_level, NULL);
goto done;
}
if (ret && slot > 0) {
dec = 1;
slot--;
}
p->slots[level] = slot;
err = setup_nodes_for_search(trans, root, p, b, level, ins_len,
&write_lock_level);
if (err == -EAGAIN)
goto again;
if (err) {
ret = err;
goto done;
}
b = p->nodes[level];
slot = p->slots[level];
/*
* Slot 0 is special, if we change the key we have to update
* the parent pointer which means we must have a write lock on
* the parent
*/
if (slot == 0 && ins_len && write_lock_level < level + 1) {
write_lock_level = level + 1;
btrfs_release_path(p);
goto again;
}
unlock_up(p, level, lowest_unlock, min_write_lock_level,
&write_lock_level);
if (level == lowest_level) {
if (dec)
p->slots[level]++;
goto done;
}
err = read_block_for_search(root, p, &b, level, slot, key);
if (err == -EAGAIN)
goto again;
if (err) {
ret = err;
goto done;
}
if (!p->skip_locking) {
level = btrfs_header_level(b);
if (level <= write_lock_level) {
if (!btrfs_try_tree_write_lock(b)) {
btrfs_set_path_blocking(p);
btrfs_tree_lock(b);
}
p->locks[level] = BTRFS_WRITE_LOCK;
} else {
if (!btrfs_tree_read_lock_atomic(b)) {
btrfs_set_path_blocking(p);
btrfs_tree_read_lock(b);
}
p->locks[level] = BTRFS_READ_LOCK;
}
p->nodes[level] = b;
}
}
ret = 1;
done: