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Commit cc15620b authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: avoid f2fs_lock_op for IPU writes 



Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp):            Process B:
f2fs_lock_all(sbi)
                        get_dnode_of_data <---- lock dn.node_page
flush_nodes             f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.

Signed-off-by: default avatarHou Pengyang <houpengyang@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent a912b54d

fs/f2fs/data.c

+31 −13
Original line number Diff line number Diff line
@@ -1383,12 +1383,12 @@ int do_write_data_page(struct f2fs_io_info *fio) 


		if (valid_ipu_blkaddr(fio)) {

			ipu_force = true;

			fio->need_lock = false;

			fio->need_lock = LOCK_DONE;

			goto got_it;

		}

	}



	if (fio->need_lock)

	if (fio->need_lock == LOCK_REQ)

		f2fs_lock_op(fio->sbi);



	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
@@ -1403,19 +1403,18 @@ int do_write_data_page(struct f2fs_io_info *fio) 
		goto out_writepage;

	}

got_it:

	err = encrypt_one_page(fio);

	if (err)

		goto out_writepage;



	set_page_writeback(page);



	/*

	 * If current allocation needs SSR,

	 * it had better in-place writes for updated data.

	 */

	if (ipu_force || (valid_ipu_blkaddr(fio) && need_inplace_update(fio))) {

		err = encrypt_one_page(fio);

		if (err)

			goto out_writepage;



		set_page_writeback(page);

		f2fs_put_dnode(&dn);

		if (fio->need_lock)

		if (fio->need_lock == LOCK_REQ)

			f2fs_unlock_op(fio->sbi);

		err = rewrite_data_page(fio);

		trace_f2fs_do_write_data_page(fio->page, IPU);
@@ -1423,6 +1422,20 @@ int do_write_data_page(struct f2fs_io_info *fio) 
		return err;

	}



	if (fio->need_lock == LOCK_RETRY) {

		if (!f2fs_trylock_op(fio->sbi)) {

			err = -EAGAIN;

			goto out_writepage;

		}

		fio->need_lock = LOCK_REQ;

	}



	err = encrypt_one_page(fio);

	if (err)

		goto out_writepage;



	set_page_writeback(page);



	/* LFS mode write path */

	write_data_page(&dn, fio);

	trace_f2fs_do_write_data_page(page, OPU);
@@ -1432,7 +1445,7 @@ int do_write_data_page(struct f2fs_io_info *fio) 
out_writepage:

	f2fs_put_dnode(&dn);

out:

	if (fio->need_lock)

	if (fio->need_lock == LOCK_REQ)

		f2fs_unlock_op(fio->sbi);

	return err;

}
@@ -1458,7 +1471,7 @@ static int __write_data_page(struct page *page, bool *submitted, 
		.page = page,

		.encrypted_page = NULL,

		.submitted = false,

		.need_lock = true,

		.need_lock = LOCK_RETRY,

	};



	trace_f2fs_writepage(page, DATA);
@@ -1494,7 +1507,7 @@ static int __write_data_page(struct page *page, bool *submitted, 


	/* Dentry blocks are controlled by checkpoint */

	if (S_ISDIR(inode->i_mode)) {

		fio.need_lock = false;

		fio.need_lock = LOCK_DONE;

		err = do_write_data_page(&fio);

		goto done;

	}
@@ -1513,8 +1526,13 @@ static int __write_data_page(struct page *page, bool *submitted, 
			goto out;

	}



	if (err == -EAGAIN)

	if (err == -EAGAIN) {

		err = do_write_data_page(&fio);

		if (err == -EAGAIN) {

			fio.need_lock = LOCK_REQ;

			err = do_write_data_page(&fio);

		}

	}

	if (F2FS_I(inode)->last_disk_size < psize)

		F2FS_I(inode)->last_disk_size = psize;

fs/f2fs/f2fs.h

+12 −1
Original line number Diff line number Diff line
@@ -799,6 +799,12 @@ enum temp_type { 
	NR_TEMP_TYPE,

};



enum need_lock_type {

	LOCK_REQ = 0,

	LOCK_DONE,

	LOCK_RETRY,

};



struct f2fs_io_info {

	struct f2fs_sb_info *sbi;	/* f2fs_sb_info pointer */

	enum page_type type;	/* contains DATA/NODE/META/META_FLUSH */
@@ -810,7 +816,7 @@ struct f2fs_io_info { 
	struct page *page;	/* page to be written */

	struct page *encrypted_page;	/* encrypted page */

	bool submitted;		/* indicate IO submission */

	bool need_lock;		/* indicate we need to lock cp_rwsem */

	int need_lock;		/* indicate we need to lock cp_rwsem */

};



#define is_read_io(rw) ((rw) == READ)
@@ -1279,6 +1285,11 @@ static inline void f2fs_lock_op(struct f2fs_sb_info *sbi) 
	down_read(&sbi->cp_rwsem);

}



static inline int f2fs_trylock_op(struct f2fs_sb_info *sbi)

{

	return down_read_trylock(&sbi->cp_rwsem);

}



static inline void f2fs_unlock_op(struct f2fs_sb_info *sbi)

{

	up_read(&sbi->cp_rwsem);

fs/f2fs/gc.c

+1 −1
Original line number Diff line number Diff line
@@ -719,7 +719,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type, 
			.old_blkaddr = NULL_ADDR,

			.page = page,

			.encrypted_page = NULL,

			.need_lock = true,

			.need_lock = LOCK_REQ,

		};

		bool is_dirty = PageDirty(page);

		int err;

fs/f2fs/segment.c

+1 −1
Original line number Diff line number Diff line
@@ -312,7 +312,7 @@ static int __commit_inmem_pages(struct inode *inode, 
			fio.page = page;

			fio.old_blkaddr = NULL_ADDR;

			fio.encrypted_page = NULL;

			fio.need_lock = false,

			fio.need_lock = LOCK_DONE;

			err = do_write_data_page(&fio);

			if (err) {

				unlock_page(page);