Re: [PATCH 2/4] btrfs: inode: remove variable shadowing in btrfs_invalidatepage()

[Su Yue <l@damenly.su>]

On Thu 17 Dec 2020 at 12:57, Qu Wenruo <wqu@suse.com> wrote:

> In btrfs_invalidatepage() we re-declare @tree variable as
> btrfs_ordered_inode_tree.
>
> Remove such variable shadowing which can be very confusing.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  fs/btrfs/inode.c | 9 +++------
>  1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index dced71bccaac..b4d36d138008 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -8169,6 +8169,7 @@ static void btrfs_invalidatepage(struct 
> page *page, unsigned int offset,
>  				 unsigned int length)
>  {
>  	struct btrfs_inode *inode = BTRFS_I(page->mapping->host);
> +	struct btrfs_ordered_inode_tree *ordered_tree = 
> &inode->ordered_tree;
>
Any reason for the declaration here? I didn't find that patch[3/4] 
use it.

>  	struct extent_io_tree *tree = &inode->io_tree;
>  	struct btrfs_ordered_extent *ordered;
>  	struct extent_state *cached_state = NULL;
> @@ -8218,15 +8219,11 @@ static void btrfs_invalidatepage(struct 
> page *page, unsigned int offset,
>  		 * for the finish_ordered_io
>  		 */
>  		if (TestClearPagePrivate2(page)) {
> -			struct btrfs_ordered_inode_tree *tree;
> -
Better to just rename the @tree to @ordered_tree.

> -			tree = &inode->ordered_tree;
> -
> -			spin_lock_irq(&tree->lock);
> +			spin_lock_irq(&ordered_tree->lock);
>  			set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
>  			ordered->truncated_len = min(ordered->truncated_len,
>  					start - ordered->file_offset);
> -			spin_unlock_irq(&tree->lock);
> +			spin_unlock_irq(&ordered_tree->lock);
>
>  			ASSERT(end - start + 1 < U32_MAX);
>  			if (btrfs_dec_test_ordered_pending(inode, &ordered,