f2fs: reduce cmd_lock coverage in __issue_discard_cmd

__submit_discard_cmd may lead long latency due to exhaustion of I/O
request resource in block layer, so issuing all discard under cmd_lock
may lead to hangtask, in order to avoid that, let's reduce it's coverage.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Chao Yu 2017-10-04 09:08:35 +08:00 committed by Jaegeuk Kim
parent 78997b569f
commit 33da62cf7a
1 changed files with 10 additions and 8 deletions

View File

@ -1158,14 +1158,14 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
int i, iter = 0, issued = 0;
bool io_interrupted = false;
mutex_lock(&dcc->cmd_lock);
f2fs_bug_on(sbi,
!__check_rb_tree_consistence(sbi, &dcc->root));
blk_start_plug(&plug);
for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
if (i + 1 < dpolicy->granularity)
break;
pend_list = &dcc->pend_list[i];
mutex_lock(&dcc->cmd_lock);
f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
blk_start_plug(&plug);
list_for_each_entry_safe(dc, tmp, pend_list, list) {
f2fs_bug_on(sbi, dc->state != D_PREP);
@ -1179,12 +1179,14 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
issued++;
skip:
if (++iter >= dpolicy->max_requests)
goto out;
break;
}
blk_finish_plug(&plug);
mutex_unlock(&dcc->cmd_lock);
if (iter >= dpolicy->max_requests)
break;
}
out:
blk_finish_plug(&plug);
mutex_unlock(&dcc->cmd_lock);
if (!issued && io_interrupted)
issued = -1;