2023-05-30 14:45:00

by Tom Rix

Subject: [PATCH] btrfs: remove unused variable pages_processed

clang with W=1 reports
fs/btrfs/extent_io.c:230:16: error: variable
'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]
unsigned long pages_processed = 0;
^
This variable is not used so remove it.

Signed-off-by: Tom Rix <[email protected]>
---
fs/btrfs/extent_io.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 89e093ae1c33..6919409c1183 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -227,7 +227,6 @@ static void __process_pages_contig(struct address_space *mapping,
pgoff_t start_index = start >> PAGE_SHIFT;
pgoff_t end_index = end >> PAGE_SHIFT;
pgoff_t index = start_index;
- unsigned long pages_processed = 0;
struct folio_batch fbatch;
int i;

@@ -242,7 +241,6 @@ static void __process_pages_contig(struct address_space *mapping,

process_one_page(fs_info, &folio->page, locked_page,
page_ops, start, end);
- pages_processed += folio_nr_pages(folio);
}
folio_batch_release(&fbatch);
cond_resched();
--
2.27.0

2023-06-01 18:49:25

by Nathan Chancellor

Subject: Re: [PATCH] btrfs: remove unused variable pages_processed

On Tue, May 30, 2023 at 10:21:54AM -0400, Tom Rix wrote:
> clang with W=1 reports
> fs/btrfs/extent_io.c:230:16: error: variable
> 'pages_processed' set but not used [-Werror,-Wunused-but-set-variable]
> unsigned long pages_processed = 0;
> ^
> This variable is not used so remove it.
>
> Signed-off-by: Tom Rix <[email protected]>

Caused by commit 6d6a31e7fc99 ("btrfs: split page locking out of
__process_pages_contig").

It is worth noting that while -Wunused-but-set-variable is normally
under W=1, btrfs explicitly enables it in their Makefile, so this
warning is visible during a normal build, which breaks the build with
CONFIG_WERROR.

Reviewed-by: Nathan Chancellor <[email protected]>

> ---
> fs/btrfs/extent_io.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 89e093ae1c33..6919409c1183 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -227,7 +227,6 @@ static void __process_pages_contig(struct address_space *mapping,
> pgoff_t start_index = start >> PAGE_SHIFT;
> pgoff_t end_index = end >> PAGE_SHIFT;
> pgoff_t index = start_index;
> - unsigned long pages_processed = 0;
> struct folio_batch fbatch;
> int i;
>
> @@ -242,7 +241,6 @@ static void __process_pages_contig(struct address_space *mapping,
>
> process_one_page(fs_info, &folio->page, locked_page,
> page_ops, start, end);
> - pages_processed += folio_nr_pages(folio);
> }
> folio_batch_release(&fbatch);
> cond_resched();
> --
> 2.27.0
>