On 04/23, Chao Yu wrote:
> Thread A Thread B
> - f2fs_ioc_commit_atomic_write
> - commit_inmem_pages
> - f2fs_submit_merged_write_cond
> : write data
> - write_checkpoint
> - do_checkpoint
> : commit all node within CP
> -> SPO
> - f2fs_do_sync_file
> - file_write_and_wait_range
> : wait data writeback
>
> In above race condition, data/node can be flushed in reversed order when
> coming a checkpoint before f2fs_do_sync_file, after SPOR, it results in
> atomic written data being corrupted.
>
> This patch adds filemap_fdatawait() in commit_inmem_pages() to keep data
> and node of atomic file being flushed orderly.
>
> Signed-off-by: Chao Yu <yuch...@huawei.com>
> ---
> fs/f2fs/file.c | 21 ++++++++++++---------
> fs/f2fs/segment.c | 2 ++
> 2 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 5d710f7f2684..4ea418cbd189 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -217,15 +217,18 @@ static int f2fs_do_sync_file(struct file *file, loff_t
> start, loff_t end,
>
> trace_f2fs_sync_file_enter(inode);
if (atomic)
goto write_done;
>
> - /* if fdatasync is triggered, let's do in-place-update */
> - if (datasync || get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
> - set_inode_flag(inode, FI_NEED_IPU);
> - ret = file_write_and_wait_range(file, start, end);
> - clear_inode_flag(inode, FI_NEED_IPU);
> -
> - if (ret) {
> - trace_f2fs_sync_file_exit(inode, cp_reason, datasync, ret);
> - return ret;
> + if (!atomic) {
> + /* if fdatasync is triggered, let's do in-place-update */
> + if (datasync || get_dirty_pages(inode) <=
> + SM_I(sbi)->min_fsync_blocks)
> + set_inode_flag(inode, FI_NEED_IPU);
> + ret = file_write_and_wait_range(file, start, end);
> + clear_inode_flag(inode, FI_NEED_IPU);
> +
> + if (ret) {
> + trace_f2fs_sync_file_exit(inode, cp_reason, datasync,
> ret);
> + return ret;
> + }
> }
write_done:
>
> /* if the inode is dirty, let's recover all the time */
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index dcb4fcb8b1b0..3b66c4aa04a6 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -420,6 +420,8 @@ static int __commit_inmem_pages(struct inode *inode)
> __revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
> } else {
> __revoke_inmem_pages(inode, &revoke_list, false, false);
> +
> + err = filemap_fdatawait(inode->i_mapping);
> }
>
> return err;
> --
> 2.15.0.55.gc2ece9dc4de6
