Commit 79963d96 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: shrink node_write lock coverage 



- to avoid race between checkpoint and quota file writeback, it
just needs to hold read lock of node_write in writeback path.
- node_write lock has covered all LFS data write paths, it's not
necessary, we only need to hold node_write lock at write path of
quota file.

This refactors commit ca7f76e6 ("f2fs: fix wrong discard space").

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent fa679555

fs/f2fs/compress.c

+15 −3
Original line number Diff line number Diff line
@@ -1096,8 +1096,16 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, 
	loff_t psize;

	int i, err;



	if (!IS_NOQUOTA(inode) && !f2fs_trylock_op(sbi))

	if (IS_NOQUOTA(inode)) {

		/*

		 * We need to wait for node_write to avoid block allocation during

		 * checkpoint. This can only happen to quota writes which can cause

		 * the below discard race condition.

		 */

		down_read(&sbi->node_write);

	} else if (!f2fs_trylock_op(sbi)) {

		return -EAGAIN;

	}



	set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
@@ -1203,7 +1211,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, 
		set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);



	f2fs_put_dnode(&dn);

	if (!IS_NOQUOTA(inode))

	if (IS_NOQUOTA(inode))

		up_read(&sbi->node_write);

	else

		f2fs_unlock_op(sbi);



	spin_lock(&fi->i_size_lock);
@@ -1230,7 +1240,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, 
out_put_dnode:

	f2fs_put_dnode(&dn);

out_unlock_op:

	if (!IS_NOQUOTA(inode))

	if (IS_NOQUOTA(inode))

		up_read(&sbi->node_write);

	else

		f2fs_unlock_op(sbi);

	return -EAGAIN;

}

fs/f2fs/data.c

+12 −0
Original line number Diff line number Diff line
@@ -2719,8 +2719,20 @@ int f2fs_write_single_data_page(struct page *page, int *submitted, 


	/* Dentry/quota blocks are controlled by checkpoint */

	if (S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) {

		/*

		 * We need to wait for node_write to avoid block allocation during

		 * checkpoint. This can only happen to quota writes which can cause

		 * the below discard race condition.

		 */

		if (IS_NOQUOTA(inode))

			down_read(&sbi->node_write);



		fio.need_lock = LOCK_DONE;

		err = f2fs_do_write_data_page(&fio);



		if (IS_NOQUOTA(inode))

			up_read(&sbi->node_write);



		goto done;

	}

fs/f2fs/segment.c

+0 −11
Original line number Diff line number Diff line
@@ -3133,14 +3133,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, 
		type = CURSEG_COLD_DATA;

	}



	/*

	 * We need to wait for node_write to avoid block allocation during

	 * checkpoint. This can only happen to quota writes which can cause

	 * the below discard race condition.

	 */

	if (IS_DATASEG(type))

		down_write(&sbi->node_write);



	down_read(&SM_I(sbi)->curseg_lock);



	mutex_lock(&curseg->curseg_mutex);
@@ -3206,9 +3198,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, 


	up_read(&SM_I(sbi)->curseg_lock);



	if (IS_DATASEG(type))

		up_write(&sbi->node_write);



	if (put_pin_sem)

		up_read(&sbi->pin_sem);

}