[PATCH 5.17 009/219] btrfs: remove unused variable in btrfs_{start,write}_dirty_block_groups()

Greg Kroah-Hartman
2022-04-18T12:17:13Z

From: Nathan Chancellor <nathan@kernel.org>

commit 6d4a6b515c39f1f8763093e0f828959b2fbc2f45 upstream.

Clang's version of -Wunused-but-set-variable recently gained support for
unary operations, which reveals two unused variables:

fs/btrfs/block-group.c:2949:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
fs/btrfs/block-group.c:3116:6: error: variable 'num_started' set but not used [-Werror,-Wunused-but-set-variable]
int num_started = 0;
^
2 errors generated.

These variables appear to be unused from their introduction, so just
remove them to silence the warnings.

Fixes: c9dc4c657850 ("Btrfs: two stage dirty block group writeout")
Fixes: 1bbc621ef284 ("Btrfs: allow block group cache writeout outside critical section in commit")
CC: stable@vger.kernel.org # 5.4+
Link: https://github.com/ClangBuiltLinux/linux/issues/1614
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/block-group.c | 4 ----
1 file changed, 4 deletions(-)

--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2922,7 +2922,6 @@ int btrfs_start_dirty_block_groups(struc
struct btrfs_path *path = NULL;
LIST_HEAD(dirty);
struct list_head *io = &cur_trans->io_bgs;
- int num_started = 0;
int loops = 0;

spin_lock(&cur_trans->dirty_bgs_lock);
@@ -2988,7 +2987,6 @@ again:
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
- num_started++;
should_put = 0;

/*
@@ -3089,7 +3087,6 @@ int btrfs_write_dirty_block_groups(struc
int should_put;
struct btrfs_path *path;
struct list_head *io = &cur_trans->io_bgs;
- int num_started = 0;

path = btrfs_alloc_path();
if (!path)
@@ -3147,7 +3144,6 @@ int btrfs_write_dirty_block_groups(struc
cache->io_ctl.inode = NULL;
ret = btrfs_write_out_cache(trans, cache, path);
if (ret == 0 && cache->io_ctl.inode) {
- num_started++;
should_put = 0;
list_add_tail(&cache->io_list, io);
} else {