# 第二次發 linux patch
[kernel org](https://lore.kernel.org/dm-devel/[e-mail]/T/#u)
閱讀 dmcache driver 時注意到 `dm_kcopyd_copy` 底下判斷 flag 的方式有機會優化，所以想試試看發 patch

先到 [linux github](https://github.com/torvalds/linux) 下載最新的 source code 我是下載 .zip

unzip linux-6.9-rc3 

設定 git

git init
git add .
git commit -m "linux-6.9-rc3"

更改程式碼
> linux-6.9-rc3/drivers/md/dm-kcopyd.c

- if (job->flags & BIT(DM_KCOPYD_WRITE_SEQ) &&
-    job->flags & BIT(DM_KCOPYD_IGNORE_ERROR))
+ if (job->flags & BIT(DM_KCOPYD_WRITE_SEQ))
    job->flags &= ~BIT(DM_KCOPYD_IGNORE_ERROR);

git

git add .
git commit -s -v
git format-patch {比較的分支}
ls *.patch

檢查 pathc 格式

./scripts/checkpatch.pl 0001-md-Reduce-flag-condition.patch

:::success
total: 0 errors, 0 warnings, 9 lines checked

0001-md-Reduce-flag-condition.patch has no obvious style problems and is ready for submission.

:::

接下來要找管理者

./scripts/get_maintainer.pl -f drivers/md/dm-kcopyd.c 

測試 email

git send-email --to [e-mail] 0001-md-Reduce-flag-condition.patch 

正式送出

git send-email --to [e-mail] --cc [e-mail] --cc [e-mail] 0001-md-Reduce-flag-condition.patch