Re: [PATCH] f2fs: allow writeback on error status filesystem

From: Chao Yu
Date: Sun Jun 07 2020 - 23:03:57 EST


On 2020/6/8 5:17, Jaegeuk Kim wrote:
> On 06/05, Chao Yu wrote:
>> 71.07% 0.01% kworker/u256:1+ [kernel.kallsyms] [k] wb_writeback
>> |
>> --71.06%--wb_writeback
>> |
>> |--68.96%--__writeback_inodes_wb
>> | |
>> | --68.95%--writeback_sb_inodes
>> | |
>> | |--65.08%--__writeback_single_inode
>> | | |
>> | | --64.35%--do_writepages
>> | | |
>> | | |--59.83%--f2fs_write_node_pages
>> | | | |
>> | | | --59.74%--f2fs_sync_node_pages
>> | | | |
>> | | | |--27.91%--pagevec_lookup_range_tag
>> | | | | |
>> | | | | --27.90%--find_get_pages_range_tag
>>
>> If filesystem was injected w/ checkpoint errror, before umount, kworker
>> will always hold one core in order to writeback a large number of node
>> pages, that looks not reasonable, to avoid that, we can allow data/node
>> write in such case, since we can force all data/node writes with OPU mode,
>> and clear recovery flag on node, and checkpoint is not allowed as well,
>> so we don't need to worry about writeback's effect on data/node in
>> previous checkpoint, then with this way, it can decrease memory footprint
>> cost by node/data pages and avoid looping into data/node writeback
>> process.
>
> This patch breaks fault injection test with filesystem corruption. Please check.

My bad, will check soon.

Thanks,

>
>>
>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>> ---
>> fs/f2fs/data.c | 19 ++++++++++++-------
>> fs/f2fs/node.c | 7 +++++--
>> 2 files changed, 17 insertions(+), 9 deletions(-)
>>
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index 9d40db50cd65..2b3c846181bb 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -2519,6 +2519,8 @@ bool f2fs_should_update_outplace(struct inode *inode, struct f2fs_io_info *fio)
>> {
>> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
>>
>> + if (unlikely(f2fs_cp_error(sbi)))
>> + return true;
>> if (f2fs_lfs_mode(sbi))
>> return true;
>> if (S_ISDIR(inode->i_mode))
>> @@ -2702,13 +2704,16 @@ int f2fs_write_single_data_page(struct page *page, int *submitted,
>> /* we should bypass data pages to proceed the kworkder jobs */
>> if (unlikely(f2fs_cp_error(sbi))) {
>> mapping_set_error(page->mapping, -EIO);
>> - /*
>> - * don't drop any dirty dentry pages for keeping lastest
>> - * directory structure.
>> - */
>> - if (S_ISDIR(inode->i_mode))
>> - goto redirty_out;
>> - goto out;
>> +
>> + if (has_not_enough_free_secs(sbi, 0, 0)) {
>> + /*
>> + * don't drop any dirty dentry pages for keeping lastest
>> + * directory structure.
>> + */
>> + if (S_ISDIR(inode->i_mode))
>> + goto redirty_out;
>> + goto out;
>> + }
>> }
>>
>> if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>> index 03e24df1c84f..372c04efad38 100644
>> --- a/fs/f2fs/node.c
>> +++ b/fs/f2fs/node.c
>> @@ -1527,7 +1527,10 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>> unlock_page(page);
>> return 0;
>> }
>> - goto redirty_out;
>> + if (has_not_enough_free_secs(sbi, 0, 0))
>> + goto redirty_out;
>> + set_fsync_mark(page, 0);
>> + set_dentry_mark(page, 0);
>> }
>>
>> if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
>> @@ -1568,7 +1571,7 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>> goto redirty_out;
>> }
>>
>> - if (atomic && !test_opt(sbi, NOBARRIER))
>> + if (atomic && !test_opt(sbi, NOBARRIER) && !f2fs_cp_error(sbi))
>> fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
>>
>> /* should add to global list before clearing PAGECACHE status */
>> --
>> 2.18.0.rc1
> .
>