On 2018/1/26 6:06, Jaegeuk Kim wrote: > On 01/25, Gaoxiang (OS) wrote: >> Previously, we attempt to flush the whole cp pack in a single bio, >> however, when suddenly powering off at this time, we could get into >> an extreme scenario that cp pack 1 page and cp pack 2 page are updated >> and latest, but payload or current summaries are still partially >> outdated. (see reliable write in the UFS specification) >> >> This patch submits the whole cp pack except cp pack 2 page at first, >> and then writes the cp pack 2 page with an extra independent >> bio with pre-io barrier. >> >> Signed-off-by: Gao Xiang <[email protected]> >> --- >> Change log from v2: >> - Apply the review comments from Chao >> Change log from v1: >> - Apply the review comments from Chao >> - time data from "finish block_ops" to " finish checkpoint" (tested on >> ARM64 with TOSHIBA 128GB UFS): >> Before patch: 0.002273 0.001973 0.002789 0.005159 0.002050 >> After patch: 0.002502 0.001624 0.002487 0.003049 0.002696 >> fs/f2fs/checkpoint.c | 39 ++++++++++++++++++++++++++++++++++----- >> 1 file changed, 34 insertions(+), 5 deletions(-) >> >> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >> index 14d2fed..c1f4b10 100644 >> --- a/fs/f2fs/checkpoint.c >> +++ b/fs/f2fs/checkpoint.c >> @@ -300,6 +300,33 @@ static int f2fs_write_meta_pages(struct address_space >> *mapping, >> return 0; >> } >> >> +static void commit_checkpoint(struct f2fs_sb_info *sbi, >> + void *src, block_t blk_addr) >> +{ >> + struct writeback_control wbc = { >> + .for_reclaim = 0, >> + }; >> + struct page *page = grab_meta_page(sbi, blk_addr); >> + int err; >> + >> + memcpy(page_address(page), src, PAGE_SIZE); >> + set_page_dirty(page); >> + >> + f2fs_wait_on_page_writeback(page, META, true); >> + f2fs_bug_on(sbi, PageWriteback(page)); >> + if (unlikely(!clear_page_dirty_for_io(page))) >> + f2fs_bug_on(sbi, 1); >> + >> + /* writeout cp pack 2 page */ >> + err = __f2fs_write_meta_page(page, &wbc, FS_CP_META_IO); >> + f2fs_bug_on(sbi, err); >> + >> + f2fs_put_page(page, 0); >> + >> + /* submit checkpoint with barrier */ >> + f2fs_submit_merged_write(sbi, META_FLUSH); >> +} >> + >> long sync_meta_pages(struct f2fs_sb_info *sbi, enum page_type type, >> long nr_to_write, enum iostat_type io_type) >> { >> @@ -1297,9 +1324,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, >> struct cp_control *cpc) >> start_blk += NR_CURSEG_NODE_TYPE; >> } >> >> - /* writeout checkpoint block */ >> - update_meta_page(sbi, ckpt, start_blk); >> - >> /* wait for previous submitted node/meta pages writeback */ >> wait_on_all_pages_writeback(sbi); > > Then, we don't need to wait for this as well as wait_on_all_pages_writeback() > in the early stage in do_checkpoint()? > > So, it seems like we can modify like below: > > --- > 1. while (get_pages()) > sync_meta_pages() > 2. if (enabled_nat_bits()) > while (get_pages()) > sync_meta_pages() > > 3. wait_on_all_pages_writeback() > -> remove
Would meta area across two devices? if it would, we need to wait all meta be persisted in second device before f2fs_flush_device_cache? > > 4. f2fs_flush_device_cache() > > 5. update_meta_page() <- for first cp_block > > 6. update_meta_page()... <- payload > > 7. orphan writes > > 8. node_summary writes > > 9. update_meta_page() <- for last cp_block > -> remove 9.1 sync_meta_pages(META) to make sure all meta IOs are issued. > > 10. wait_on_all_pages_writeback() > > ---- > Add) 11. commit_checkpoint() > - update_meta_page() <- for last cp_block > - sync_meta_pages(META_FLUSH) > > We don't need to wait for page_writeback any more. > >> >> @@ -1313,10 +1337,15 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, >> struct cp_control *cpc) >> sbi->last_valid_block_count = sbi->total_valid_block_count; >> percpu_counter_set(&sbi->alloc_valid_block_count, 0); >> >> - /* Here, we only have one bio having CP pack */ >> - sync_meta_pages(sbi, META_FLUSH, LONG_MAX, FS_CP_META_IO); >> + /* Here, we have one bio having CP pack except cp pack 2 page */ >> + sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO); >> >> /* wait for previous submitted meta pages writeback */ >> + if (!test_opt(sbi, NOBARRIER)) > > The above has nothing to do with this patch. We only need to use wait_on_all_pages_writeback to keep writeback order of previous metadata and last cp pack metadata if barrier is on? Thanks, > >> + wait_on_all_pages_writeback(sbi); >> + >> + /* barrier and flush checkpoint cp pack 2 page */ >> + commit_checkpoint(sbi, ckpt, start_blk); >> wait_on_all_pages_writeback(sbi); >> >> release_ino_entry(sbi, false); >> -- >> 2.1.4 > > . > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
