Messages in this thread | | | Date | Thu, 10 Nov 2016 12:03:40 -0800 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] f2fs: don't wait writeback for datas during checkpoint |
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Hi Chao,
On Thu, Nov 10, 2016 at 07:40:03PM +0800, Chao Yu wrote: > Normally, while committing checkpoint, we will wait on all pages to be > writebacked no matter the page is data or metadata, so in scenario where > there are lots of data IO being submitted with metadata, we may suffer > long latency for waiting writeback during checkpoint. > > Indeed, we only care about persistence for pages with metadata, but not > pages with data, as file system consistent are only related to metadate, > so in order to avoid encountering long latency in above scenario, let's > recognize and reference metadata in submitted IOs, wait writeback only > for metadatas. > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > --- > fs/f2fs/checkpoint.c | 2 +- > fs/f2fs/data.c | 9 +++++++-- > fs/f2fs/debug.c | 7 ++++--- > fs/f2fs/f2fs.h | 26 +++++++++++++++++++++++--- > fs/f2fs/gc.c | 2 ++ > fs/f2fs/node.c | 1 + > fs/f2fs/segment.c | 2 ++ > 7 files changed, 40 insertions(+), 9 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 7bece59..bdf8a50 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -1003,7 +1003,7 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi) > for (;;) { > prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE); > > - if (!atomic_read(&sbi->nr_wb_bios)) > + if (!get_pages(sbi, F2FS_WB_META)) > break; > > io_schedule_timeout(5*HZ); > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 66d2aee..2fb1ffd 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -73,6 +73,7 @@ static void f2fs_write_end_io(struct bio *bio) > > bio_for_each_segment_all(bvec, bio, i) { > struct page *page = bvec->bv_page; > + bool is_meta = f2fs_is_meta_data(page); > > fscrypt_pullback_bio_page(&page, true); > > @@ -80,9 +81,10 @@ static void f2fs_write_end_io(struct bio *bio) > mapping_set_error(page->mapping, -EIO); > f2fs_stop_checkpoint(sbi, true); > } > + dec_page_count(sbi, is_meta ? F2FS_WB_META : F2FS_WB_DATA); > end_page_writeback(page); > } > - if (atomic_dec_and_test(&sbi->nr_wb_bios) && > + if (!get_pages(sbi, F2FS_WB_META) && > wq_has_sleeper(&sbi->cp_wait)) > wake_up(&sbi->cp_wait); > > @@ -111,7 +113,6 @@ static inline void __submit_bio(struct f2fs_sb_info *sbi, > struct bio *bio, enum page_type type) > { > if (!is_read_io(bio_op(bio))) { > - atomic_inc(&sbi->nr_wb_bios); > if (f2fs_sb_mounted_blkzoned(sbi->sb) && > current->plug && (type == DATA || type == NODE)) > blk_finish_plug(current->plug); > @@ -272,6 +273,9 @@ void f2fs_submit_page_mbio(struct f2fs_io_info *fio) > verify_block_addr(sbi, fio->old_blkaddr); > verify_block_addr(sbi, fio->new_blkaddr); > > + if (!is_read) > + inc_page_count(sbi, fio->is_meta ? F2FS_WB_META : F2FS_WB_DATA); > +
How about using f2fs_is_meta_data(page) instead of changing fio?
Thanks,
> down_write(&io->io_rwsem); > > if (io->bio && (io->last_block_in_bio != fio->new_blkaddr - 1 || > @@ -1237,6 +1241,7 @@ static int f2fs_write_data_page(struct page *page, > .type = DATA, > .op = REQ_OP_WRITE, > .op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0, > + .is_meta = S_ISDIR(inode->i_mode), > .page = page, > .encrypted_page = NULL, > }; > diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c > index 2fdf233..f2d87de 100644 > --- a/fs/f2fs/debug.c > +++ b/fs/f2fs/debug.c > @@ -50,7 +50,8 @@ static void update_general_status(struct f2fs_sb_info *sbi) > si->ndirty_files = sbi->ndirty_inode[FILE_INODE]; > si->ndirty_all = sbi->ndirty_inode[DIRTY_META]; > si->inmem_pages = get_pages(sbi, F2FS_INMEM_PAGES); > - si->wb_bios = atomic_read(&sbi->nr_wb_bios); > + si->nr_wb_meta = get_pages(sbi, F2FS_WB_META); > + si->nr_wb_data = get_pages(sbi, F2FS_WB_DATA); > si->total_count = (int)sbi->user_block_count / sbi->blocks_per_seg; > si->rsvd_segs = reserved_segments(sbi); > si->overp_segs = overprovision_segments(sbi); > @@ -313,8 +314,8 @@ static int stat_show(struct seq_file *s, void *v) > seq_printf(s, " - Inner Struct Count: tree: %d(%d), node: %d\n", > si->ext_tree, si->zombie_tree, si->ext_node); > seq_puts(s, "\nBalancing F2FS Async:\n"); > - seq_printf(s, " - inmem: %4d, wb_bios: %4d\n", > - si->inmem_pages, si->wb_bios); > + seq_printf(s, " - inmem: %4d, wb_meta: %4d, wb_data: %4d\n", > + si->inmem_pages, si->nr_wb_meta, si->nr_wb_data); > seq_printf(s, " - nodes: %4d in %4d\n", > si->ndirty_node, si->node_pages); > seq_printf(s, " - dents: %4d in dirs:%4d (%4d)\n", > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 23a937f..95ad091 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -682,6 +682,8 @@ enum count_type { > F2FS_DIRTY_META, > F2FS_INMEM_PAGES, > F2FS_DIRTY_IMETA, > + F2FS_WB_META, > + F2FS_WB_DATA, > NR_COUNT_TYPE, > }; > > @@ -715,6 +717,7 @@ struct f2fs_io_info { > enum page_type type; /* contains DATA/NODE/META/META_FLUSH */ > int op; /* contains REQ_OP_ */ > int op_flags; /* rq_flag_bits */ > + bool is_meta; /* checkpoint needs to wait its writeback */ > block_t new_blkaddr; /* new block address to be written */ > block_t old_blkaddr; /* old block address before Cow */ > struct page *page; /* page to be written */ > @@ -849,7 +852,6 @@ struct f2fs_sb_info { > block_t discard_blks; /* discard command candidats */ > block_t last_valid_block_count; /* for recovery */ > u32 s_next_generation; /* for NFS support */ > - atomic_t nr_wb_bios; /* # of writeback bios */ > > /* # of pages, see count_type */ > atomic_t nr_pages[NR_COUNT_TYPE]; > @@ -1193,6 +1195,23 @@ static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid) > return 0; > } > > +static inline bool f2fs_is_meta_data(struct page *page) > +{ > + struct address_space *mapping = page->mapping; > + struct inode *inode; > + > + /* it is bounce page of encrypted regular inode */ > + if (!mapping) > + return false; > + > + inode = mapping->host; > + if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)) || > + inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)) || > + S_ISDIR(inode->i_mode)) > + return true; > + return false; > +} > + > #define F2FS_DEFAULT_ALLOCATED_BLOCKS 1 > > /* > @@ -1263,7 +1282,8 @@ static inline void inc_page_count(struct f2fs_sb_info *sbi, int count_type) > { > atomic_inc(&sbi->nr_pages[count_type]); > > - if (count_type == F2FS_DIRTY_DATA || count_type == F2FS_INMEM_PAGES) > + if (count_type == F2FS_DIRTY_DATA || count_type == F2FS_INMEM_PAGES || > + count_type == F2FS_WB_META || count_type == F2FS_WB_DATA) > return; > > set_sbi_flag(sbi, SBI_IS_DIRTY); > @@ -2219,7 +2239,7 @@ struct f2fs_stat_info { > unsigned int ndirty_dirs, ndirty_files, ndirty_all; > int nats, dirty_nats, sits, dirty_sits, free_nids, alloc_nids; > int total_count, utilization; > - int bg_gc, wb_bios; > + int bg_gc, nr_wb_meta, nr_wb_data; > int inline_xattr, inline_inode, inline_dir, orphans; > unsigned int valid_count, valid_node_count, valid_inode_count, discard_blks; > unsigned int bimodal, avg_vblocks; > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index f8d8cc96a..6b762d4 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -554,6 +554,7 @@ static void move_encrypted_block(struct inode *inode, block_t bidx, > .type = DATA, > .op = REQ_OP_READ, > .op_flags = READ_SYNC, > + .is_meta = true, > .encrypted_page = NULL, > }; > struct dnode_of_data dn; > @@ -674,6 +675,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type, > .type = DATA, > .op = REQ_OP_WRITE, > .op_flags = WRITE_SYNC, > + .is_meta = S_ISDIR(inode->i_mode), > .page = page, > .encrypted_page = NULL, > }; > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index d58438f..3c7e00c 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -1574,6 +1574,7 @@ static int f2fs_write_node_page(struct page *page, > .type = NODE, > .op = REQ_OP_WRITE, > .op_flags = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : 0, > + .is_meta = true, > .page = page, > .encrypted_page = NULL, > }; > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 078c571..b34e20a 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -261,6 +261,7 @@ static int __commit_inmem_pages(struct inode *inode, > .type = DATA, > .op = REQ_OP_WRITE, > .op_flags = WRITE_SYNC | REQ_PRIO, > + .is_meta = false, > .encrypted_page = NULL, > }; > bool submit_bio = false; > @@ -1573,6 +1574,7 @@ void write_meta_page(struct f2fs_sb_info *sbi, struct page *page) > .type = META, > .op = REQ_OP_WRITE, > .op_flags = WRITE_SYNC | REQ_META | REQ_PRIO, > + .is_meta = true, > .old_blkaddr = page->index, > .new_blkaddr = page->index, > .page = page, > -- > 2.8.2.311.gee88674
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