btrfs: Remove redundant WARN_ON in walk_down_log_tree (36ee0b44) · Commits · 戴 / test

level <0 and level >= BTRFS_MAX_LEVEL are already performed upon extent buffer read by tree checker in btrfs_check_node. go. As far as 'level <= 0' we are guaranteed that level is '> 0' because the value of level _before_ reading 'next' is larger than 1 (otherwise we wouldn't have executed that code at all) this in turn guarantees that 'level' after btrfs_read_buffer is 'level - 1' since we verify this invariant in: btrfs_read_buffer btree_read_extent_buffer_pages btrfs_verify_level_key This guarantees that level can never be '<= 0' so the warn on is never triggered. Signed-off-by:

Nikolay Borisov <nborisov@suse.com> Reviewed-by:

David Sterba <dsterba@suse.com> Signed-off-by:

David Sterba <dsterba@suse.com>

fs/btrfs/tree-log.c

+0 −9

Original line number	Diff line number	Diff line
		@@ -2674,14 +2674,9 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
		u32 blocksize;
		int ret = 0;

		WARN_ON(*level < 0);
		WARN_ON(*level >= BTRFS_MAX_LEVEL);

		while (*level > 0) {
		struct btrfs_key first_key;

		WARN_ON(*level < 0);
		WARN_ON(*level >= BTRFS_MAX_LEVEL);
		cur = path->nodes[*level];

		WARN_ON(btrfs_header_level(cur) != *level);
		@@ -2748,7 +2743,6 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
		return ret;
		}

		WARN_ON(*level <= 0);
		if (path->nodes[*level-1])
		free_extent_buffer(path->nodes[*level-1]);
		path->nodes[*level-1] = next;
		@@ -2756,9 +2750,6 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
		path->slots[*level] = 0;
		cond_resched();
		}
		WARN_ON(*level < 0);
		WARN_ON(*level >= BTRFS_MAX_LEVEL);

		path->slots[level] = btrfs_header_nritems(path->nodes[level]);

		cond_resched();

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