On 2018/1/31 14:39, 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 outdated.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]> > Reviewed-by: Chao Yu <[email protected]> > --- > Change log from v3: > - further review comments are applied from Jaegeuk and Chao > - Tested on this patch (without multiple-device): mount, boot Android with > f2fs userdata and make fragment > - If any problem with this patch or I miss something, please kindly share > your comments, thanks :) > 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 | 67 > ++++++++++++++++++++++++++++++++++++---------------- > 1 file changed, 46 insertions(+), 21 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 14d2fed..916dc72 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -1158,6 +1158,39 @@ static void update_ckpt_flags(struct f2fs_sb_info > *sbi, struct cp_control *cpc) > spin_unlock_irqrestore(&sbi->cp_lock, flags); > } > > +static void commit_checkpoint(struct f2fs_sb_info *sbi, > + void *src, block_t blk_addr) > +{ > + struct writeback_control wbc = { > + .for_reclaim = 0, > + }; > + > + /* > + * pagevec_lookup_tag and lock_page again will take > + * some extra time. Therefore, update_meta_pages and > + * sync_meta_pages are combined in this function. > + */ > + 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 if NOBARRIER is not set) */ > + f2fs_submit_merged_write(sbi, META_FLUSH); > +} > + > static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > { > struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); > @@ -1260,16 +1293,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, > struct cp_control *cpc) > } > } > > - /* need to wait for end_io results */ > - wait_on_all_pages_writeback(sbi); > - if (unlikely(f2fs_cp_error(sbi))) > - return -EIO; > - > - /* flush all device cache */ > - err = f2fs_flush_device_cache(sbi); > - if (err) > - return err; > - > /* write out checkpoint buffer at block 0 */ > update_meta_page(sbi, ckpt, start_blk++); > > @@ -1297,15 +1320,6 @@ 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); > - > - if (unlikely(f2fs_cp_error(sbi))) > - return -EIO; > - > filemap_fdatawait_range(NODE_MAPPING(sbi), 0, LLONG_MAX); > filemap_fdatawait_range(META_MAPPING(sbi), 0, LLONG_MAX); > > @@ -1313,12 +1327,23 @@ 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); > + > + /* flush all device cache */ > + err = f2fs_flush_device_cache(sbi); > + if (err) > + return err; > > /* wait for previous submitted meta pages writeback */ > wait_on_all_pages_writeback(sbi);
Move f2fs_flush_device_cache here? since meta area can cross the multiple devices, we should make sure all metadata were in device cache at least, and then trigger the flush. > > + if (unlikely(f2fs_cp_error(sbi))) > + return -EIO; > + > + /* barrier and flush checkpoint cp pack 2 page if it can */ > + commit_checkpoint(sbi, ckpt, start_blk); Jaegeuk, are we really allow to make critical do_checkpoint which is on path of fsync()/sync() be asynchronous? Thanks, > + > release_ino_entry(sbi, false); > > if (unlikely(f2fs_cp_error(sbi))) > ------------------------------------------------------------------------------ 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
