2022-04-01 14:50:10

by Jakob Koschel

Subject: [PATCH 2/2] f2fs: replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <[email protected]>
---
fs/f2fs/segment.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 81ef2c3d08e5..037164bf40a6 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1666,33 +1666,32 @@ static unsigned int __wait_discard_cmd_range(struct f2fs_sb_info *sbi,
struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
struct list_head *wait_list = (dpolicy->type == DPOLICY_FSTRIM) ?
&(dcc->fstrim_list) : &(dcc->wait_list);
- struct discard_cmd *dc, *tmp;
- bool need_wait;
+ struct discard_cmd *dc = NULL, *iter, *tmp;
unsigned int trimmed = 0;

next:
- need_wait = false;
+ dc = NULL;

mutex_lock(&dcc->cmd_lock);
- list_for_each_entry_safe(dc, tmp, wait_list, list) {
- if (dc->lstart + dc->len <= start || end <= dc->lstart)
+ list_for_each_entry_safe(iter, tmp, wait_list, list) {
+ if (iter->lstart + iter->len <= start || end <= iter->lstart)
continue;
- if (dc->len < dpolicy->granularity)
+ if (iter->len < dpolicy->granularity)
continue;
- if (dc->state == D_DONE && !dc->ref) {
- wait_for_completion_io(&dc->wait);
- if (!dc->error)
- trimmed += dc->len;
- __remove_discard_cmd(sbi, dc);
+ if (iter->state == D_DONE && !iter->ref) {
+ wait_for_completion_io(&iter->wait);
+ if (!iter->error)
+ trimmed += iter->len;
+ __remove_discard_cmd(sbi, iter);
} else {
- dc->ref++;
- need_wait = true;
+ iter->ref++;
+ dc = iter;
break;
}
}
mutex_unlock(&dcc->cmd_lock);

- if (need_wait) {
+ if (dc) {
trimmed += __wait_one_discard_bio(sbi, dc);
goto next;
}
--
2.25.1

2022-04-12 22:41:41

by Chao Yu

Subject: Re: [PATCH 2/2] f2fs: replace usage of found with dedicated list iterator variable

On 2022/4/1 6:16, Jakob Koschel wrote:
> To move the list iterator variable into the list_for_each_entry_*()
> macro in the future it should be avoided to use the list iterator
> variable after the loop body.
>
> To *never* use the list iterator variable after the loop it was
> concluded to use a separate iterator variable instead of a
> found boolean [1].
>
> This removes the need to use a found variable and simply checking if
> the variable was set, can determine if the break/goto was hit.
>
> Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
> Signed-off-by: Jakob Koschel <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,