Commit fb24fea7 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: change to use rwsem for gc_mutex 



Mutex lock won't serialize callers, in order to avoid starving of unlucky
caller, let's use rwsem lock instead.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent d7b0a23d

fs/f2fs/f2fs.h

+4 −1
Original line number Diff line number Diff line
@@ -1391,7 +1391,10 @@ struct f2fs_sb_info { 
	struct f2fs_mount_info mount_opt;	/* mount options */



	/* for cleaning operations */

	struct mutex gc_mutex;			/* mutex for GC */

	struct rw_semaphore gc_lock;		/*

						 * semaphore for GC, avoid

						 * race between GC and GC or CP

						 */

	struct f2fs_gc_kthread	*gc_thread;	/* GC thread */

	unsigned int cur_victim_sec;		/* current victim section num */

	unsigned int gc_mode;			/* current GC state */

fs/f2fs/file.c

+6 −6
Original line number Diff line number Diff line
@@ -1642,7 +1642,7 @@ static int expand_inode_data(struct inode *inode, loff_t offset, 
next_alloc:

		if (has_not_enough_free_secs(sbi, 0,

			GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {

			mutex_lock(&sbi->gc_mutex);

			down_write(&sbi->gc_lock);

			err = f2fs_gc(sbi, true, false, NULL_SEGNO);

			if (err && err != -ENODATA && err != -EAGAIN)

				goto out_err;
@@ -2450,12 +2450,12 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg) 
		return ret;



	if (!sync) {

		if (!mutex_trylock(&sbi->gc_mutex)) {

		if (!down_write_trylock(&sbi->gc_lock)) {

			ret = -EBUSY;

			goto out;

		}

	} else {

		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

	}



	ret = f2fs_gc(sbi, sync, true, NULL_SEGNO);
@@ -2493,12 +2493,12 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg) 


do_more:

	if (!range.sync) {

		if (!mutex_trylock(&sbi->gc_mutex)) {

		if (!down_write_trylock(&sbi->gc_lock)) {

			ret = -EBUSY;

			goto out;

		}

	} else {

		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

	}



	ret = f2fs_gc(sbi, range.sync, true, GET_SEGNO(sbi, range.start));
@@ -2929,7 +2929,7 @@ static int f2fs_ioc_flush_device(struct file *filp, unsigned long arg) 
	end_segno = min(start_segno + range.segments, dev_end_segno);



	while (start_segno < end_segno) {

		if (!mutex_trylock(&sbi->gc_mutex)) {

		if (!down_write_trylock(&sbi->gc_lock)) {

			ret = -EBUSY;

			goto out;

		}

fs/f2fs/gc.c

+6 −6
Original line number Diff line number Diff line
@@ -78,18 +78,18 @@ static int gc_thread_func(void *data) 
		 */

		if (sbi->gc_mode == GC_URGENT) {

			wait_ms = gc_th->urgent_sleep_time;

			mutex_lock(&sbi->gc_mutex);

			down_write(&sbi->gc_lock);

			goto do_gc;

		}



		if (!mutex_trylock(&sbi->gc_mutex)) {

		if (!down_write_trylock(&sbi->gc_lock)) {

			stat_other_skip_bggc_count(sbi);

			goto next;

		}



		if (!is_idle(sbi, GC_TIME)) {

			increase_sleep_time(gc_th, &wait_ms);

			mutex_unlock(&sbi->gc_mutex);

			up_write(&sbi->gc_lock);

			stat_io_skip_bggc_count(sbi);

			goto next;

		}
@@ -1370,7 +1370,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, 
				reserved_segments(sbi),

				prefree_segments(sbi));



	mutex_unlock(&sbi->gc_mutex);

	up_write(&sbi->gc_lock);



	put_gc_inode(&gc_list);
@@ -1409,9 +1409,9 @@ static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start, 
			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),

		};



		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

		do_garbage_collect(sbi, segno, &gc_list, FG_GC);

		mutex_unlock(&sbi->gc_mutex);

		up_write(&sbi->gc_lock);

		put_gc_inode(&gc_list);



		if (get_valid_blocks(sbi, segno, true))

fs/f2fs/segment.c

+3 −3
Original line number Diff line number Diff line
@@ -504,7 +504,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need) 
	 * dir/node pages without enough free segments.

	 */

	if (has_not_enough_free_secs(sbi, 0, 0)) {

		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

		f2fs_gc(sbi, false, false, NULL_SEGNO);

	}

}
@@ -2860,9 +2860,9 @@ int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range) 
	if (sbi->discard_blks == 0)

		goto out;



	mutex_lock(&sbi->gc_mutex);

	down_write(&sbi->gc_lock);

	err = f2fs_write_checkpoint(sbi, &cpc);

	mutex_unlock(&sbi->gc_mutex);

	up_write(&sbi->gc_lock);

	if (err)

		goto out;

fs/f2fs/super.c

+8 −8
Original line number Diff line number Diff line
@@ -1238,9 +1238,9 @@ int f2fs_sync_fs(struct super_block *sb, int sync) 


		cpc.reason = __get_cp_reason(sbi);



		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

		err = f2fs_write_checkpoint(sbi, &cpc);

		mutex_unlock(&sbi->gc_mutex);

		up_write(&sbi->gc_lock);

	}

	f2fs_trace_ios(NULL, 1);
@@ -1621,7 +1621,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) 
	f2fs_update_time(sbi, DISABLE_TIME);



	while (!f2fs_time_over(sbi, DISABLE_TIME)) {

		mutex_lock(&sbi->gc_mutex);

		down_write(&sbi->gc_lock);

		err = f2fs_gc(sbi, true, false, NULL_SEGNO);

		if (err == -ENODATA) {

			err = 0;
@@ -1643,7 +1643,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) 
		goto restore_flag;

	}



	mutex_lock(&sbi->gc_mutex);

	down_write(&sbi->gc_lock);

	cpc.reason = CP_PAUSE;

	set_sbi_flag(sbi, SBI_CP_DISABLED);

	err = f2fs_write_checkpoint(sbi, &cpc);
@@ -1655,7 +1655,7 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) 
	spin_unlock(&sbi->stat_lock);



out_unlock:

	mutex_unlock(&sbi->gc_mutex);

	up_write(&sbi->gc_lock);

restore_flag:

	sbi->sb->s_flags = s_flags;	/* Restore MS_RDONLY status */

	return err;
@@ -1663,12 +1663,12 @@ static int f2fs_disable_checkpoint(struct f2fs_sb_info *sbi) 


static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi)

{

	mutex_lock(&sbi->gc_mutex);

	down_write(&sbi->gc_lock);

	f2fs_dirty_to_prefree(sbi);



	clear_sbi_flag(sbi, SBI_CP_DISABLED);

	set_sbi_flag(sbi, SBI_IS_DIRTY);

	mutex_unlock(&sbi->gc_mutex);

	up_write(&sbi->gc_lock);



	f2fs_sync_fs(sbi->sb, 1);

}
@@ -3398,7 +3398,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) 


	/* init f2fs-specific super block info */

	sbi->valid_super_block = valid_super_block;

	mutex_init(&sbi->gc_mutex);

	init_rwsem(&sbi->gc_lock);

	mutex_init(&sbi->writepages);

	mutex_init(&sbi->cp_mutex);

	mutex_init(&sbi->resize_mutex);