Re: [PATCH v3] f2fs: add bio cache for IPU
From: Chao Yu
Date: Mon Dec 24 2018 - 01:35:52 EST
Jaegeuk,
Will kernel still hang with this v3?
Thanks,
On 2018/12/19 17:29, Chao Yu wrote:
> SQLite in Wal mode may trigger sequential IPU write in db-wal file, after
> commit d1b3e72d5490 ("f2fs: submit bio of in-place-update pages"), we
> lost the chance of merging page in inner managed bio cache, result in
> submitting more small-sized IO.
>
> So let's add temporary bio in writepages() to cache mergeable write IO as
> much as possible.
>
> Test case:
> 1. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"
> 2. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"
>
> Before:
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65552, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65560, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65568, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65576, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65584, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65592, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65600, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65608, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65616, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65624, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65632, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65640, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65648, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65656, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65664, size = 4096
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57352, size = 4096
>
> After:
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 65536
> f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57368, size = 4096
>
> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> ---
> v3:
> - introduce f2fs_submit_ipu_bio() to check page Writeback status.
> fs/f2fs/data.c | 85 ++++++++++++++++++++++++++++++++++++++++++-----
> fs/f2fs/f2fs.h | 3 ++
> fs/f2fs/segment.c | 5 ++-
> 3 files changed, 84 insertions(+), 9 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index cdfe9a7b856e..e5cd3fd9e215 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -341,20 +341,20 @@ 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,
> +static bool __has_merged_page(struct bio *bio, struct inode *inode,
> struct page *page, nid_t ino)
> {
> struct bio_vec *bvec;
> struct page *target;
> int i;
>
> - if (!io->bio)
> + if (!bio)
> return false;
>
> if (!inode && !page && !ino)
> return true;
>
> - bio_for_each_segment_all(bvec, io->bio, i) {
> + bio_for_each_segment_all(bvec, bio, i) {
>
> if (bvec->bv_page->mapping)
> target = bvec->bv_page;
> @@ -405,7 +405,7 @@ static void __submit_merged_write_cond(struct f2fs_sb_info *sbi,
> struct f2fs_bio_info *io = sbi->write_io[btype] + temp;
>
> down_read(&io->io_rwsem);
> - ret = __has_merged_page(io, inode, page, ino);
> + ret = __has_merged_page(io->bio, inode, page, ino);
> up_read(&io->io_rwsem);
> }
> if (ret)
> @@ -474,6 +474,59 @@ int f2fs_submit_page_bio(struct f2fs_io_info *fio)
> return 0;
> }
>
> +int f2fs_merge_page_bio(struct f2fs_io_info *fio)
> +{
> + struct bio *bio = *fio->bio;
> + struct page *page = fio->encrypted_page ?
> + fio->encrypted_page : fio->page;
> +
> + if (!f2fs_is_valid_blkaddr(fio->sbi, fio->new_blkaddr,
> + __is_meta_io(fio) ? META_GENERIC : DATA_GENERIC))
> + return -EFAULT;
> +
> + trace_f2fs_submit_page_bio(page, fio);
> + f2fs_trace_ios(fio, 0);
> +
> + if (bio && (*fio->last_block + 1 != fio->new_blkaddr ||
> + !__same_bdev(fio->sbi, fio->new_blkaddr, bio))) {
> + __submit_bio(fio->sbi, bio, fio->type);
> + bio = NULL;
> + }
> +alloc_new:
> + if (!bio) {
> + bio = __bio_alloc(fio->sbi, fio->new_blkaddr, fio->io_wbc,
> + BIO_MAX_PAGES, false, fio->type, fio->temp);
> + *fio->last_block = fio->new_blkaddr;
> + bio_set_op_attrs(bio, fio->op, fio->op_flags);
> + }
> +
> + if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
> + __submit_bio(fio->sbi, bio, fio->type);
> + bio = NULL;
> + goto alloc_new;
> + }
> +
> + if (fio->io_wbc)
> + wbc_account_io(fio->io_wbc, page, PAGE_SIZE);
> +
> + *fio->last_block = fio->new_blkaddr;
> +
> + inc_page_count(fio->sbi, WB_DATA_TYPE(fio->page));
> +
> + *fio->bio = bio;
> + return 0;
> +}
> +
> +void f2fs_submit_ipu_bio(struct f2fs_sb_info *sbi, struct bio *bio,
> + struct page *page)
> +{
> + if (!__has_merged_page(bio, NULL, page, 0))
> + return;
> +
> + if (bio)
> + __submit_bio(sbi, bio, DATA);
> +}
> +
> void f2fs_submit_page_write(struct f2fs_io_info *fio)
> {
> struct f2fs_sb_info *sbi = fio->sbi;
> @@ -1903,6 +1956,8 @@ int f2fs_do_write_data_page(struct f2fs_io_info *fio)
> }
>
> static int __write_data_page(struct page *page, bool *submitted,
> + struct bio **bio,
> + sector_t *last_block,
> struct writeback_control *wbc,
> enum iostat_type io_type)
> {
> @@ -1928,6 +1983,8 @@ static int __write_data_page(struct page *page, bool *submitted,
> .need_lock = LOCK_RETRY,
> .io_type = io_type,
> .io_wbc = wbc,
> + .bio = bio,
> + .last_block = last_block,
> };
>
> trace_f2fs_writepage(page, DATA);
> @@ -2029,6 +2086,10 @@ static int __write_data_page(struct page *page, bool *submitted,
> f2fs_balance_fs(sbi, need_balance_fs);
>
> if (unlikely(f2fs_cp_error(sbi))) {
> + if (bio && *bio) {
> + __submit_bio(sbi, *bio, DATA);
> + *bio = NULL;
> + }
> f2fs_submit_merged_write(sbi, DATA);
> submitted = NULL;
> }
> @@ -2055,7 +2116,7 @@ static int __write_data_page(struct page *page, bool *submitted,
> static int f2fs_write_data_page(struct page *page,
> struct writeback_control *wbc)
> {
> - return __write_data_page(page, NULL, wbc, FS_DATA_IO);
> + return __write_data_page(page, NULL, NULL, NULL, wbc, FS_DATA_IO);
> }
>
> /*
> @@ -2071,6 +2132,8 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> int done = 0;
> struct pagevec pvec;
> struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
> + struct bio *bio = NULL;
> + sector_t last_block;
> int nr_pages;
> pgoff_t uninitialized_var(writeback_index);
> pgoff_t index;
> @@ -2147,17 +2210,20 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> }
>
> if (PageWriteback(page)) {
> - if (wbc->sync_mode != WB_SYNC_NONE)
> + if (wbc->sync_mode != WB_SYNC_NONE) {
> f2fs_wait_on_page_writeback(page,
> DATA, true);
> - else
> + f2fs_submit_ipu_bio(sbi, bio, page);
> + } else {
> goto continue_unlock;
> + }
> }
>
> if (!clear_page_dirty_for_io(page))
> goto continue_unlock;
>
> - ret = __write_data_page(page, &submitted, wbc, io_type);
> + ret = __write_data_page(page, &submitted, &bio,
> + &last_block, wbc, io_type);
> if (unlikely(ret)) {
> /*
> * keep nr_to_write, since vfs uses this to
> @@ -2206,6 +2272,9 @@ static int f2fs_write_cache_pages(struct address_space *mapping,
> if (nwritten)
> f2fs_submit_merged_write_cond(F2FS_M_SB(mapping), mapping->host,
> NULL, 0, DATA);
> + /* submit cached bio of IPU write */
> + if (bio)
> + __submit_bio(sbi, bio, DATA);
>
> return ret;
> }
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 9e56c78fe519..eeede26339a8 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -1044,6 +1044,8 @@ struct f2fs_io_info {
> bool retry; /* need to reallocate block address */
> enum iostat_type io_type; /* io type */
> struct writeback_control *io_wbc; /* writeback control */
> + struct bio **bio; /* bio for ipu */
> + sector_t *last_block; /* last block number in bio */
> unsigned char version; /* version of the node */
> };
>
> @@ -3105,6 +3107,7 @@ void f2fs_submit_merged_write_cond(struct f2fs_sb_info *sbi,
> 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);
> +int f2fs_merge_page_bio(struct f2fs_io_info *fio);
> void f2fs_submit_page_write(struct f2fs_io_info *fio);
> struct block_device *f2fs_target_device(struct f2fs_sb_info *sbi,
> block_t blk_addr, struct bio *bio);
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 3241e0619275..a361d61b005e 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -3163,7 +3163,10 @@ int f2fs_inplace_write_data(struct f2fs_io_info *fio)
>
> stat_inc_inplace_blocks(fio->sbi);
>
> - err = f2fs_submit_page_bio(fio);
> + if (fio->bio)
> + err = f2fs_merge_page_bio(fio);
> + else
> + err = f2fs_submit_page_bio(fio);
> if (!err)
> update_device_state(fio);
>
>