Commit 02d91398 authored by Daeho Jeong's avatar Daeho Jeong Committed by Jaegeuk Kim
Browse files

f2fs: fix to freeze GC and discard threads quickly 



Suspend can fail if kernel threads do not freeze for a while.
f2fs_gc and f2fs_discard threads can perform long-running operations
that prevent them from reaching a freeze point in a timely manner.

This patch adds explicit freezing checks in the following locations:
1. f2fs_gc: Added a check at the 'retry' label to exit the loop quickly
   if freezing is requested, especially during heavy GC rounds.
2. __issue_discard_cmd: Added a 'suspended' flag to break both inner and
   outer loops during discard command issuance if freezing is detected
   after at least one command has been issued.
3. __issue_discard_cmd_orderly: Added a similar check for orderly discard
   to ensure responsiveness.

These checks ensure that the threads release locks safely and enter the
frozen state.

Signed-off-by: default avatarDaeho Jeong <daehojeong@google.com>
Reviewed-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 7b9161a6

fs/f2fs/gc.c

+10 −0
Original line number Diff line number Diff line
@@ -1895,12 +1895,18 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, 
				sbi->next_victim_seg[gc_type] =

					(cur_segno + 1 < sec_end_segno) ?

					cur_segno + 1 : NULL_SEGNO;



			if (unlikely(freezing(current))) {

				folio_put_refs(sum_folio, 2);

				goto stop;

			}

		}

next_block:

		folio_put_refs(sum_folio, 2);

		segno = block_end_segno;

	}



stop:

	if (submitted)

		f2fs_submit_merged_write(sbi, data_type);
@@ -1974,6 +1980,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control) 
		goto stop;

	}

retry:

	if (unlikely(freezing(current))) {

		ret = 0;

		goto stop;

	}

	ret = __get_victim(sbi, &segno, gc_type, gc_control->one_time);

	if (ret) {

		/* allow to search victim from sections has pinned data */

fs/f2fs/segment.c

+11 −1
Original line number Diff line number Diff line
@@ -1606,6 +1606,9 @@ static void __issue_discard_cmd_orderly(struct f2fs_sb_info *sbi, 
		if (dc->state != D_PREP)

			goto next;



		if (*issued > 0 && unlikely(freezing(current)))

			break;



		if (dpolicy->io_aware && !is_idle(sbi, DISCARD_TIME)) {

			io_interrupted = true;

			break;
@@ -1645,6 +1648,7 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, 
	struct blk_plug plug;

	int i, issued;

	bool io_interrupted = false;

	bool suspended = false;



	if (dpolicy->timeout)

		f2fs_update_time(sbi, UMOUNT_DISCARD_TIMEOUT);
@@ -1675,6 +1679,11 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, 
		list_for_each_entry_safe(dc, tmp, pend_list, list) {

			f2fs_bug_on(sbi, dc->state != D_PREP);



			if (issued > 0 && unlikely(freezing(current))) {

				suspended = true;

				break;

			}



			if (dpolicy->timeout &&

				f2fs_time_over(sbi, UMOUNT_DISCARD_TIMEOUT))

				break;
@@ -1694,7 +1703,8 @@ static int __issue_discard_cmd(struct f2fs_sb_info *sbi, 
next:

		mutex_unlock(&dcc->cmd_lock);



		if (issued >= dpolicy->max_requests || io_interrupted)

		if (issued >= dpolicy->max_requests || io_interrupted ||

					suspended)

			break;

	}