Commit d530d4d8 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: support synchronous gc in ioctl 



This patch drops in batches gc triggered through ioctl, since user
can easily control the gc by designing the loop around the ->ioctl.

We support synchronous gc by forcing using FG_GC in f2fs_gc, so with
it, user can make sure that in this round all blocks gced were
persistent in the device until ioctl returned.

Signed-off-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 3342bb30

fs/f2fs/f2fs.h

+1 −1
Original line number Diff line number Diff line
@@ -1830,7 +1830,7 @@ int f2fs_release_page(struct page *, gfp_t); 
int start_gc_thread(struct f2fs_sb_info *);

void stop_gc_thread(struct f2fs_sb_info *);

block_t start_bidx_of_node(unsigned int, struct f2fs_inode_info *);

int f2fs_gc(struct f2fs_sb_info *);

int f2fs_gc(struct f2fs_sb_info *, bool);

void build_gc_manager(struct f2fs_sb_info *);



/*

fs/f2fs/file.c

+9 −13
Original line number Diff line number Diff line
@@ -1618,29 +1618,25 @@ static int f2fs_ioc_gc(struct file *filp, unsigned long arg) 
{

	struct inode *inode = file_inode(filp);

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	__u32 i, count;

	__u32 sync;



	if (!capable(CAP_SYS_ADMIN))

		return -EPERM;



	if (get_user(count, (__u32 __user *)arg))

	if (get_user(sync, (__u32 __user *)arg))

		return -EFAULT;



	if (!count || count > F2FS_BATCH_GC_MAX_NUM)

		return -EINVAL;

	if (f2fs_readonly(sbi->sb))

		return -EROFS;



	for (i = 0; i < count; i++) {

	if (!sync) {

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

			break;



		if (f2fs_gc(sbi))

			break;

			return -EBUSY;

	} else {

		mutex_lock(&sbi->gc_mutex);

	}



	if (put_user(i, (__u32 __user *)arg))

		return -EFAULT;



	return 0;

	return f2fs_gc(sbi, sync);

}



long f2fs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

fs/f2fs/gc.c

+13 −8
Original line number Diff line number Diff line
@@ -78,7 +78,7 @@ static int gc_thread_func(void *data) 
		stat_inc_bggc_count(sbi);



		/* if return value is not zero, no victim was selected */

		if (f2fs_gc(sbi))

		if (f2fs_gc(sbi, false))

			wait_ms = gc_th->no_gc_sleep_time;



		/* balancing f2fs's metadata periodically */
@@ -803,12 +803,12 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, 
	return nfree;

}



int f2fs_gc(struct f2fs_sb_info *sbi)

int f2fs_gc(struct f2fs_sb_info *sbi, bool sync)

{

	unsigned int segno, i;

	int gc_type = BG_GC;

	int gc_type = sync ? FG_GC : BG_GC;

	int sec_freed = 0;

	int ret = -1;

	int ret = -EINVAL;

	struct cp_control cpc;

	struct gc_inode_list gc_list = {

		.ilist = LIST_HEAD_INIT(gc_list.ilist),
@@ -855,15 +855,20 @@ gc_more: 
	if (gc_type == FG_GC)

		sbi->cur_victim_sec = NULL_SEGNO;



	if (!sync) {

		if (has_not_enough_free_secs(sbi, sec_freed))

			goto gc_more;



		if (gc_type == FG_GC)

			write_checkpoint(sbi, &cpc);

	}

stop:

	mutex_unlock(&sbi->gc_mutex);



	put_gc_inode(&gc_list);



	if (sync)

		ret = sec_freed ? 0 : -EAGAIN;

	return ret;

}

fs/f2fs/gc.h

+0 −6
Original line number Diff line number Diff line
@@ -19,12 +19,6 @@ 
#define LIMIT_INVALID_BLOCK	40 /* percentage over total user space */

#define LIMIT_FREE_BLOCK	40 /* percentage over invalid + free space */



/*

 * with this macro, we can control the max time we do garbage collection,

 * when user triggers batch mode gc by ioctl.

 */

#define F2FS_BATCH_GC_MAX_NUM		16



/* Search max. number of dirty segments to select a victim segment */

#define DEF_MAX_VICTIM_SEARCH 4096 /* covers 8GB */

fs/f2fs/segment.c

+1 −1
Original line number Diff line number Diff line
@@ -295,7 +295,7 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi) 
	 */

	if (has_not_enough_free_secs(sbi, 0)) {

		mutex_lock(&sbi->gc_mutex);

		f2fs_gc(sbi);

		f2fs_gc(sbi, false);

	}

}

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