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Commit 5b5162d0 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
Browse files

f2fs: fix out-place-update DIO write 



In get_more_blocks(), we may override @create as below code:

	create = dio->op == REQ_OP_WRITE;
	if (dio->flags & DIO_SKIP_HOLES) {
		if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
						i_blkbits))
			create = 0;
	}

But in f2fs_map_blocks(), we only trigger f2fs_balance_fs() if @create
is 1, so in LFS mode, dio overwrite under LFS mode can easily run out
of free segments, result in below panic.

 Call Trace:
  allocate_segment_by_default+0xa8/0x270 [f2fs]
  f2fs_allocate_data_block+0x1ea/0x5c0 [f2fs]
  __allocate_data_block+0x306/0x480 [f2fs]
  f2fs_map_blocks+0x6f6/0x920 [f2fs]
  __get_data_block+0x4f/0xb0 [f2fs]
  get_data_block_dio_write+0x50/0x60 [f2fs]
  do_blockdev_direct_IO+0xcd5/0x21e0
  __blockdev_direct_IO+0x3a/0x3c
  f2fs_direct_IO+0x1ff/0x4a0 [f2fs]
  generic_file_direct_write+0xd9/0x160
  __generic_file_write_iter+0xbb/0x1e0
  f2fs_file_write_iter+0xaf/0x220 [f2fs]
  __vfs_write+0xd0/0x130
  vfs_write+0xb2/0x1b0
  SyS_pwrite64+0x69/0xa0
  ? vtime_user_exit+0x29/0x70
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25
 RIP: new_curseg+0x36f/0x380 [f2fs] RSP: ffffac570393f7a8

So this patch introduces a parameter map.m_may_create to indicate that
f2fs_map_blocks() is called from write or read path, which can give the
right hint to let f2fs_map_blocks() trigger OPU allocation and call
f2fs_balanc_fs() correctly.

BTW, it disables physical address preallocation for direct IO in
f2fs_preallocate_blocks, which is redundant to OPU allocation of
f2fs_map_blocks.

Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 504ab57a

fs/f2fs/data.c

+29 −13
Original line number Diff line number Diff line
@@ -954,6 +954,9 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) 
			return err;

	}



	if (direct_io && allow_outplace_dio(inode, iocb, from))

		return 0;



	if (is_inode_flag_set(inode, FI_NO_PREALLOC))

		return 0;
@@ -967,6 +970,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from) 
	map.m_next_pgofs = NULL;

	map.m_next_extent = NULL;

	map.m_seg_type = NO_CHECK_TYPE;

	map.m_may_create = true;



	if (direct_io) {

		map.m_seg_type = f2fs_rw_hint_to_seg_type(iocb->ki_hint);
@@ -1025,7 +1029,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, 
	unsigned int maxblocks = map->m_len;

	struct dnode_of_data dn;

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	int mode = create ? ALLOC_NODE : LOOKUP_NODE;

	int mode = map->m_may_create ? ALLOC_NODE : LOOKUP_NODE;

	pgoff_t pgofs, end_offset, end;

	int err = 0, ofs = 1;

	unsigned int ofs_in_node, last_ofs_in_node;
@@ -1059,7 +1063,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, 
	}



next_dnode:

	if (create)

	if (map->m_may_create)

		__do_map_lock(sbi, flag, true);



	/* When reading holes, we need its node page */
@@ -1096,8 +1100,8 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, 


	if (is_valid_data_blkaddr(sbi, blkaddr)) {

		/* use out-place-update for driect IO under LFS mode */

		if (test_opt(sbi, LFS) && create &&

				flag == F2FS_GET_BLOCK_DIO) {

		if (test_opt(sbi, LFS) && flag == F2FS_GET_BLOCK_DIO &&

							map->m_may_create) {

			err = __allocate_data_block(&dn, map->m_seg_type);

			if (!err)

				set_inode_flag(inode, FI_APPEND_WRITE);
@@ -1206,7 +1210,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, 


	f2fs_put_dnode(&dn);



	if (create) {

	if (map->m_may_create) {

		__do_map_lock(sbi, flag, false);

		f2fs_balance_fs(sbi, dn.node_changed);

	}
@@ -1232,7 +1236,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, 
	}

	f2fs_put_dnode(&dn);

unlock_out:

	if (create) {

	if (map->m_may_create) {

		__do_map_lock(sbi, flag, false);

		f2fs_balance_fs(sbi, dn.node_changed);

	}
@@ -1268,7 +1272,7 @@ bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len) 


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)

			pgoff_t *next_pgofs, int seg_type, bool may_write)

{

	struct f2fs_map_blocks map;

	int err;
@@ -1278,6 +1282,7 @@ static int __get_data_block(struct inode *inode, sector_t iblock, 
	map.m_next_pgofs = next_pgofs;

	map.m_next_extent = NULL;

	map.m_seg_type = seg_type;

	map.m_may_create = may_write;



	err = f2fs_map_blocks(inode, &map, create, flag);

	if (!err) {
@@ -1294,7 +1299,16 @@ static int get_data_block(struct inode *inode, sector_t iblock, 
{

	return __get_data_block(inode, iblock, bh_result, create,

							flag, next_pgofs,

							NO_CHECK_TYPE);

							NO_CHECK_TYPE, create);

}



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

			struct buffer_head *bh_result, int create)

{

	return __get_data_block(inode, iblock, bh_result, create,

				F2FS_GET_BLOCK_DIO, NULL,

				f2fs_rw_hint_to_seg_type(inode->i_write_hint),

				true);

}



static int get_data_block_dio(struct inode *inode, sector_t iblock,
@@ -1302,8 +1316,8 @@ static int get_data_block_dio(struct inode *inode, sector_t iblock, 
{

	return __get_data_block(inode, iblock, bh_result, create,

				F2FS_GET_BLOCK_DIO, NULL,

						f2fs_rw_hint_to_seg_type(

							inode->i_write_hint));

				f2fs_rw_hint_to_seg_type(inode->i_write_hint),

				false);

}



static int get_data_block_bmap(struct inode *inode, sector_t iblock,
@@ -1315,7 +1329,7 @@ static int get_data_block_bmap(struct inode *inode, sector_t iblock, 


	return __get_data_block(inode, iblock, bh_result, create,

						F2FS_GET_BLOCK_BMAP, NULL,

						NO_CHECK_TYPE);

						NO_CHECK_TYPE, create);

}



static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
@@ -1522,6 +1536,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping, 
	map.m_next_pgofs = NULL;

	map.m_next_extent = NULL;

	map.m_seg_type = NO_CHECK_TYPE;

	map.m_may_create = false;



	for (; nr_pages; nr_pages--) {

		if (pages) {
@@ -2639,7 +2654,8 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 
	}



	err = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,

			iter, get_data_block_dio, NULL, f2fs_dio_submit_bio,

			iter, rw == WRITE ? get_data_block_dio_write :

			get_data_block_dio, NULL, f2fs_dio_submit_bio,

			DIO_LOCKING | DIO_SKIP_HOLES);



	if (do_opu)

fs/f2fs/f2fs.h

+1 −0
Original line number Diff line number Diff line
@@ -601,6 +601,7 @@ struct f2fs_map_blocks { 
	pgoff_t *m_next_pgofs;		/* point next possible non-hole pgofs */

	pgoff_t *m_next_extent;		/* point to next possible extent */

	int m_seg_type;

	bool m_may_create;		/* indicate it is from write path */

};



/* for flag in get_data_block */

fs/f2fs/file.c

+2 −1
Original line number Diff line number Diff line
@@ -1502,7 +1502,8 @@ static int expand_inode_data(struct inode *inode, loff_t offset, 
{

	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);

	struct f2fs_map_blocks map = { .m_next_pgofs = NULL,

			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE };

			.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE,

			.m_may_create = true };

	pgoff_t pg_end;

	loff_t new_size = i_size_read(inode);

	loff_t off_end;