Re: [f2fs-dev] [PATCH RESEND v2] Revert: "f2fs: check last page index in cached bio to decide submission"

From: Chao Yu
Date: Thu Sep 27 2018 - 03:50:32 EST


On 2018/9/27 15:40, Sahitya Tummala wrote:
> On Wed, Sep 26, 2018 at 10:44:56PM +0800, Chao Yu wrote:
>> From: Chao Yu <yuchao0@xxxxxxxxxx>
>>
>> There is one case that we can leave bio in f2fs, result in hanging
>> page writeback waiter.
>>
>> Thread A Thread B
>> - f2fs_write_cache_pages
>> - f2fs_submit_page_write
>> page #0 cached in bio #0 of cold log
>> - f2fs_submit_page_write
>> page #1 cached in bio #1 of warm log
>> - f2fs_write_cache_pages
>> - f2fs_submit_page_write
>> bio is full, submit bio #1 contain page #1
>> - f2fs_submit_merged_write_cond(, page #1)
>> fail to submit bio #0 due to page #1 is not in any cached bios.
>>
>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>> ---
>> v2:
>> - rebase to dev-test
>> fs/f2fs/checkpoint.c | 2 +-
>> fs/f2fs/data.c | 38 +++++++++++++++++++-------------------
>> fs/f2fs/f2fs.h | 4 ++--
>> fs/f2fs/node.c | 12 ++++++------
>> fs/f2fs/segment.c | 11 +++++------
>> 5 files changed, 33 insertions(+), 34 deletions(-)
>>
>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
>> index d624d7983197..2f63b362ce63 100644
>> --- a/fs/f2fs/checkpoint.c
>> +++ b/fs/f2fs/checkpoint.c
>> @@ -280,7 +280,7 @@ static int __f2fs_write_meta_page(struct page *page,
>>
>> if (wbc->for_reclaim)
>> f2fs_submit_merged_write_cond(sbi, page->mapping->host,
>> - 0, page->index, META);
>> + page, 0, META);
>>
>> unlock_page(page);
>>
>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>> index be69b6ac6870..b03f9d163175 100644
>> --- a/fs/f2fs/data.c
>> +++ b/fs/f2fs/data.c
>> @@ -322,8 +322,8 @@ static void __submit_merged_bio(struct f2fs_bio_info *io)
>> io->bio = NULL;
>> }
>>
>> -static bool __has_merged_page(struct f2fs_bio_info *io,
>> - struct inode *inode, nid_t ino, pgoff_t idx)
>> +static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
>> + struct page *page, nid_t ino)
>> {
>> struct bio_vec *bvec;
>> struct page *target;
>> @@ -332,7 +332,7 @@ static bool __has_merged_page(struct f2fs_bio_info *io,
>> if (!io->bio)
>> return false;
>>
>> - if (!inode && !ino)
>> + if (!inode && !page && !ino)
>> return true;
>>
>> bio_for_each_segment_all(bvec, io->bio, i) {
>> @@ -342,11 +342,10 @@ static bool __has_merged_page(struct f2fs_bio_info *io,
>> else
>> target = fscrypt_control_page(bvec->bv_page);
>>
>> - if (idx != target->index)
>> - continue;
>> -
>> if (inode && inode == target->mapping->host)
>> return true;
>> + if (page && page == target)
>> + return true;
>
> If both inode and page are passed, then I think it we should check for page first
> followed by inode checks. What do you think?

Yes, I've changed this and would like to check in latter tests.

But, it's strange, yesterday, I remember I've passed all tests, but when I
retest this patch at home, I got stuck and obviously there are compiler
warning... I guess I'm missing something yesterday.

Thanks,

>
>> if (ino && ino == ino_of_node(target))
>> return true;
>> }
>> @@ -355,7 +354,8 @@ static bool __has_merged_page(struct f2fs_bio_info *io,
>> }
>>
>> static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
>> - nid_t ino, pgoff_t idx, enum page_type type)
>> + struct page *page, nid_t ino,
>> + enum page_type type)
>> {
>> enum page_type btype = PAGE_TYPE_OF_BIO(type);
>> enum temp_type temp;
>> @@ -366,7 +366,7 @@ static bool has_merged_page(struct f2fs_sb_info *sbi, struct inode *inode,
>> io = sbi->write_io[btype] + temp;
>>
>> down_read(&io->io_rwsem);
>> - ret = __has_merged_page(io, inode, ino, idx);
>> + ret = __has_merged_page(io, inode, page, ino);
>> up_read(&io->io_rwsem);
>>
>> /* TODO: use HOT temp only for meta pages now. */
>> @@ -397,12 +397,12 @@ static void __f2fs_submit_merged_write(struct f2fs_sb_info *sbi,
>> }
>>
>> static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
>> - struct inode *inode, nid_t ino, pgoff_t idx,
>> - enum page_type type, bool force)
>> + struct inode *inode, struct page *page,
>> + nid_t ino, enum page_type type, bool force)
>> {
>> enum temp_type temp;
>>
>> - if (!force && !has_merged_page(sbi, inode, ino, idx, type))
>> + if (!force && !has_merged_page(sbi, inode, page, ino, type))
>> return;
>>
>> for (temp = HOT; temp < NR_TEMP_TYPE; temp++) {
>> @@ -421,10 +421,10 @@ void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type)
>> }
>>
>> void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
>> - struct inode *inode, nid_t ino, pgoff_t idx,
>> - enum page_type type)
>> + struct inode *inode, struct page *page,
>> + nid_t ino, enum page_type type)
>> {
>> - __submit_merged_write_cond(sbi, inode, ino, idx, type, false);
>> + __submit_merged_write_cond(sbi, inode, page, ino, type, false);
>> }
>>
>> void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi)
>> @@ -1962,7 +1962,7 @@ static int __write_data_page(struct page *page, bool *submitted,
>> ClearPageUptodate(page);
>>
>> if (wbc->for_reclaim) {
>> - f2fs_submit_merged_write_cond(sbi, inode, 0, page->index, DATA);
>> + f2fs_submit_merged_write_cond(sbi, inode, page, 0, DATA);
>> clear_inode_flag(inode, FI_HOT_DATA);
>> f2fs_remove_dirty_inode(inode);
>> submitted = NULL;
>> @@ -2020,10 +2020,10 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>> pgoff_t index;
>> pgoff_t end; /* Inclusive */
>> pgoff_t done_index;
>> - pgoff_t last_idx = ULONG_MAX;
>> int cycled;
>> int range_whole = 0;
>> int tag;
>> + int nwritten = 0;
>>
>> pagevec_init(&pvec);
>>
>> @@ -2126,7 +2126,7 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>> done = 1;
>> break;
>> } else if (submitted) {
>> - last_idx = page->index;
>> + nwritten++;
>> }
>>
>> if (--wbc->nr_to_write <= 0 &&
>> @@ -2148,9 +2148,9 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
>> if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
>> mapping->writeback_index = done_index;
>>
>> - if (last_idx != ULONG_MAX)
>> + if (nwritten)
>> f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
>> - 0, last_idx, DATA);
>> + NULL, 0, DATA);
>>
>> return ret;
>> }
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index dc9306e87a51..464545e40729 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -3049,8 +3049,8 @@ int f2fs_init_post_read_processing(void);
>> void f2fs_destroy_post_read_processing(void);
>> void f2fs_submit_merged_write(struct f2fs_sb_info *sbi, enum page_type type);
>> void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
>> - struct inode *inode, nid_t ino, pgoff_t idx,
>> - enum page_type type);
>> + struct inode *inode, struct page *page,
>> + nid_t ino, enum page_type type);
>> void f2fs_flush_merged_writes(struct f2fs_sb_info *sbi);
>> int f2fs_submit_page_bio(struct f2fs_io_info *fio);
>> void f2fs_submit_page_write(struct f2fs_io_info *fio);
>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
>> index ea151e07790f..c47ca807e245 100644
>> --- a/fs/f2fs/node.c
>> +++ b/fs/f2fs/node.c
>> @@ -1561,8 +1561,8 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
>> up_read(&sbi->node_write);
>>
>> if (wbc->for_reclaim) {
>> - f2fs_submit_merged_write_cond(sbi, page->mapping->host, 0,
>> - page->index, NODE);
>> + f2fs_submit_merged_write_cond(sbi, page->mapping->host,
>> + page, 0, NODE);
>> submitted = NULL;
>> }
>>
>> @@ -1634,13 +1634,13 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>> unsigned int *seq_id)
>> {
>> pgoff_t index;
>> - pgoff_t last_idx = ULONG_MAX;
>> struct pagevec pvec;
>> int ret = 0;
>> struct page *last_page = NULL;
>> bool marked = false;
>> nid_t ino = inode->i_ino;
>> int nr_pages;
>> + int nwritten = 0;
>>
>> if (atomic) {
>> last_page = last_fsync_dnode(sbi, ino);
>> @@ -1718,7 +1718,7 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>> f2fs_put_page(last_page, 0);
>> break;
>> } else if (submitted) {
>> - last_idx = page->index;
>> + nwritten++;
>> }
>>
>> if (page == last_page) {
>> @@ -1744,8 +1744,8 @@ int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
>> goto retry;
>> }
>> out:
>> - if (last_idx != ULONG_MAX)
>> - f2fs_submit_merged_write_cond(sbi, NULL, ino, last_idx, NODE);
>> + if (nwritten)
>> + f2fs_submit_merged_write_cond(sbi, NULL, NULL, ino, NODE);
>> return ret ? -EIO: 0;
>> }
>>
>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>> index 97a4fae75651..965ef524e2a2 100644
>> --- a/fs/f2fs/segment.c
>> +++ b/fs/f2fs/segment.c
>> @@ -371,7 +371,7 @@ static int __f2fs_commit_inmem_pages(struct inode *inode)
>> .io_type = FS_DATA_IO,
>> };
>> struct list_head revoke_list;
>> - pgoff_t last_idx = ULONG_MAX;
>> + bool submit_bio = false;
>> int err = 0;
>>
>> INIT_LIST_HEAD(&revoke_list);
>> @@ -406,14 +406,14 @@ static int __f2fs_commit_inmem_pages(struct inode *inode)
>> }
>> /* record old blkaddr for revoking */
>> cur->old_addr = fio.old_blkaddr;
>> - last_idx = page->index;
>> + submit_bio = true;
>> }
>> unlock_page(page);
>> list_move_tail(&cur->list, &revoke_list);
>> }
>>
>> - if (last_idx != ULONG_MAX)
>> - f2fs_submit_merged_write_cond(sbi, inode, 0, last_idx, DATA);
>> + if (submit_bio)
>> + f2fs_submit_merged_write_cond(sbi, inode, NULL, 0, DATA);
>>
>> if (err) {
>> /*
>> @@ -3179,8 +3179,7 @@ void f2fs_wait_on_page_writeback(struct page *page,
>> if (PageWriteback(page)) {
>> struct f2fs_sb_info *sbi = F2FS_P_SB(page);
>>
>> - f2fs_submit_merged_write_cond(sbi, page->mapping->host,
>> - 0, page->index, type);
>> + f2fs_submit_merged_write_cond(sbi, NULL, page, 0, type);
>> if (ordered)
>> wait_on_page_writeback(page);
>> else
>> --
>> 2.18.0
>>
>>
>>
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>