Commit b91050a8 authored by Hyunchul Lee's avatar Hyunchul Lee Committed by Jaegeuk Kim
Browse files

f2fs: add nowait aio support 



This patch adds nowait aio support[1].

Return EAGAIN if any of the following checks fail for direct I/O:
  - i_rwsem is not lockable
  - Blocks are not allocated at the write location

And xfstests generic/471 is passed.

 [1]: 6be96d "Introduce RWF_NOWAIT and FMODE_AIO_NOWAIT"

Signed-off-by: default avatarHyunchul Lee <cheol.lee@lge.com>
Reviewed-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 63189b78

fs/f2fs/data.c

+37 −10
Original line number Diff line number Diff line
@@ -839,13 +839,6 @@ alloc: 
	return 0;

}



static inline bool __force_buffered_io(struct inode *inode, int rw)

{

	return (f2fs_encrypted_file(inode) ||

			(rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||

			F2FS_I_SB(inode)->s_ndevs);

}



int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)

{

	struct inode *inode = file_inode(iocb->ki_filp);
@@ -877,7 +870,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) 


	if (direct_io) {

		map.m_seg_type = rw_hint_to_seg_type(iocb->ki_hint);

		flag = __force_buffered_io(inode, WRITE) ?

		flag = f2fs_force_buffered_io(inode, WRITE) ?

					F2FS_GET_BLOCK_PRE_AIO :

					F2FS_GET_BLOCK_PRE_DIO;

		goto map_blocks;
@@ -1121,6 +1114,31 @@ out: 
	return err;

}



bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len)

{

	struct f2fs_map_blocks map;

	block_t last_lblk;

	int err;



	if (pos + len > i_size_read(inode))

		return false;



	map.m_lblk = F2FS_BYTES_TO_BLK(pos);

	map.m_next_pgofs = NULL;

	map.m_next_extent = NULL;

	map.m_seg_type = NO_CHECK_TYPE;

	last_lblk = F2FS_BLK_ALIGN(pos + len);



	while (map.m_lblk < last_lblk) {

		map.m_len = last_lblk - map.m_lblk;

		err = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_DEFAULT);

		if (err || map.m_len == 0)

			return false;

		map.m_lblk += map.m_len;

	}

	return true;

}



static int __get_data_block(struct inode *inode, sector_t iblock,

			struct buffer_head *bh, int create, int flag,

			pgoff_t *next_pgofs, int seg_type)
@@ -2306,7 +2324,7 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
	if (err)

		return err;



	if (__force_buffered_io(inode, rw))

	if (f2fs_force_buffered_io(inode, rw))

		return 0;



	trace_f2fs_direct_IO_enter(inode, offset, count, rw);
@@ -2314,7 +2332,15 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
	if (rw == WRITE && whint_mode == WHINT_MODE_OFF)

		iocb->ki_hint = WRITE_LIFE_NOT_SET;



	if (!down_read_trylock(&F2FS_I(inode)->dio_rwsem[rw])) {

		if (iocb->ki_flags & IOCB_NOWAIT) {

			iocb->ki_hint = hint;

			err = -EAGAIN;

			goto out;

		}

		down_read(&F2FS_I(inode)->dio_rwsem[rw]);

	}



	err = blockdev_direct_IO(iocb, inode, iter, get_data_block_dio);

	up_read(&F2FS_I(inode)->dio_rwsem[rw]);
@@ -2330,6 +2356,7 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
		}

	}



out:

	trace_f2fs_direct_IO_exit(inode, offset, count, rw, err);



	return err;

fs/f2fs/f2fs.h

+8 −0
Original line number Diff line number Diff line
@@ -2877,6 +2877,7 @@ int f2fs_release_page(struct page *page, gfp_t wait); 
int f2fs_migrate_page(struct address_space *mapping, struct page *newpage,

			struct page *page, enum migrate_mode mode);

#endif

bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len);



/*

 * gc.c
@@ -3261,4 +3262,11 @@ static inline bool f2fs_may_encrypt(struct inode *inode) 
#endif

}



static inline bool f2fs_force_buffered_io(struct inode *inode, int rw)

{

	return (f2fs_encrypted_file(inode) ||

			(rw == WRITE && test_opt(F2FS_I_SB(inode), LFS)) ||

			F2FS_I_SB(inode)->s_ndevs);

}



#endif

fs/f2fs/file.c

+29 −6
Original line number Diff line number Diff line
@@ -480,6 +480,9 @@ static int f2fs_file_open(struct inode *inode, struct file *filp) 


	if (err)

		return err;



	filp->f_mode |= FMODE_NOWAIT;



	return dquot_file_open(inode, filp);

}
@@ -2896,7 +2899,15 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 
	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode))))

		return -EIO;



	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))

		return -EINVAL;



	if (!inode_trylock(inode)) {

		if (iocb->ki_flags & IOCB_NOWAIT)

			return -EAGAIN;

		inode_lock(inode);

	}



	ret = generic_write_checks(iocb, from);

	if (ret > 0) {

		int err;
@@ -2904,12 +2915,24 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) 
		if (iov_iter_fault_in_readable(from, iov_iter_count(from)))

			set_inode_flag(inode, FI_NO_PREALLOC);



		if ((iocb->ki_flags & IOCB_NOWAIT) &&

			(iocb->ki_flags & IOCB_DIRECT)) {

				if (!f2fs_overwrite_io(inode, iocb->ki_pos,

						iov_iter_count(from)) ||

					f2fs_has_inline_data(inode) ||

					f2fs_force_buffered_io(inode, WRITE)) {

						inode_unlock(inode);

						return -EAGAIN;

				}



		} else {

			err = f2fs_preallocate_blocks(iocb, from);

			if (err) {

				clear_inode_flag(inode, FI_NO_PREALLOC);

				inode_unlock(inode);

				return err;

			}

		}

		blk_start_plug(&plug);

		ret = __generic_file_write_iter(iocb, from);

		blk_finish_plug(&plug);

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