Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery
On 2016/9/21 8:45, Jaegeuk Kim wrote: > @@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct page > *page, block_t blkaddr) > { > struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page)); > struct f2fs_node *rn = F2FS_NODE(page); > + size_t crc_offset = le32_to_cpu(ckpt->checksum_offset); > + __u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver); > + __u64 crc; > > - rn->footer.cp_ver = ckpt->checkpoint_ver; > + crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset))); > + cp_ver |= (crc << 32); How about using '^=' here? > + rn->footer.cp_ver = cpu_to_le64(cp_ver); > rn->footer.next_blkaddr = cpu_to_le32(blkaddr); > } > > -static inline nid_t ino_of_node(struct page *node_page) > -{ > - struct f2fs_node *rn = F2FS_NODE(node_page); > - return le32_to_cpu(rn->footer.ino); > -} > - > -static inline nid_t nid_of_node(struct page *node_page) > -{ > - struct f2fs_node *rn = F2FS_NODE(node_page); > - return le32_to_cpu(rn->footer.nid); > -} > - > -static inline unsigned int ofs_of_node(struct page *node_page) > -{ > - struct f2fs_node *rn = F2FS_NODE(node_page); > - unsigned flag = le32_to_cpu(rn->footer.flag); > - return flag >> OFFSET_BIT_SHIFT; > -} > - > -static inline unsigned long long cpver_of_node(struct page *node_page) > +static inline bool is_recoverable_dnode(struct page *page) > { > - struct f2fs_node *rn = F2FS_NODE(node_page); > - return le64_to_cpu(rn->footer.cp_ver); > -} > + struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page)); > + size_t crc_offset = le32_to_cpu(ckpt->checksum_offset); > + __u64 cp_ver = cur_cp_version(ckpt); > + __u64 crc; > > -static inline block_t next_blkaddr_of_node(struct page *node_page) > -{ > - struct f2fs_node *rn = F2FS_NODE(node_page); > - return le32_to_cpu(rn->footer.next_blkaddr); > + crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset))); > + cp_ver |= (crc << 32); > + return cpu_to_le64(cp_ver) == cpver_of_node(page); > } cpu_to_le64(cp_ver) == cpver_of_node(page) ^ (crc << 32) Thanks,
Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery
On Sat, Sep 24, 2016 at 02:00:41PM +0800, Chao Yu wrote: > On 2016/9/21 8:45, Jaegeuk Kim wrote: > > @@ -259,40 +290,26 @@ static inline void fill_node_footer_blkaddr(struct > > page *page, block_t blkaddr) > > { > > struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page)); > > struct f2fs_node *rn = F2FS_NODE(page); > > + size_t crc_offset = le32_to_cpu(ckpt->checksum_offset); > > + __u64 cp_ver = le64_to_cpu(ckpt->checkpoint_ver); > > + __u64 crc; > > > > - rn->footer.cp_ver = ckpt->checkpoint_ver; > > + crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset))); > > + cp_ver |= (crc << 32); > > How about using '^=' here? The crc is already random enough, but has 32bits only. The cp_ver is not easy to use over 32bits, so we don't need to keep the other 32bits untouched in most of life. Thanks, > > > + rn->footer.cp_ver = cpu_to_le64(cp_ver); > > rn->footer.next_blkaddr = cpu_to_le32(blkaddr); > > } > > > > -static inline nid_t ino_of_node(struct page *node_page) > > -{ > > - struct f2fs_node *rn = F2FS_NODE(node_page); > > - return le32_to_cpu(rn->footer.ino); > > -} > > - > > -static inline nid_t nid_of_node(struct page *node_page) > > -{ > > - struct f2fs_node *rn = F2FS_NODE(node_page); > > - return le32_to_cpu(rn->footer.nid); > > -} > > - > > -static inline unsigned int ofs_of_node(struct page *node_page) > > -{ > > - struct f2fs_node *rn = F2FS_NODE(node_page); > > - unsigned flag = le32_to_cpu(rn->footer.flag); > > - return flag >> OFFSET_BIT_SHIFT; > > -} > > - > > -static inline unsigned long long cpver_of_node(struct page *node_page) > > +static inline bool is_recoverable_dnode(struct page *page) > > { > > - struct f2fs_node *rn = F2FS_NODE(node_page); > > - return le64_to_cpu(rn->footer.cp_ver); > > -} > > + struct f2fs_checkpoint *ckpt = F2FS_CKPT(F2FS_P_SB(page)); > > + size_t crc_offset = le32_to_cpu(ckpt->checksum_offset); > > + __u64 cp_ver = cur_cp_version(ckpt); > > + __u64 crc; > > > > -static inline block_t next_blkaddr_of_node(struct page *node_page) > > -{ > > - struct f2fs_node *rn = F2FS_NODE(node_page); > > - return le32_to_cpu(rn->footer.next_blkaddr); > > + crc = le32_to_cpu(*((__le32 *)((unsigned char *)ckpt + crc_offset))); > > + cp_ver |= (crc << 32); > > + return cpu_to_le64(cp_ver) == cpver_of_node(page); > > } > > cpu_to_le64(cp_ver) == cpver_of_node(page) ^ (crc << 32) > > Thanks,
Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery
Hi Jaegeuk, On 2016/9/20 10:55, Jaegeuk Kim wrote: > Previously, we used cp_version only to detect recoverable dnodes. > In order to avoid same garbage cp_version, we needed to truncate the next > dnode during checkpoint, resulting in additional discard or data write. > If we can distinguish this by using crc in addition to cp_version, we can > remove this overhead. > > There is backward compatibility concern where it changes node_footer layout. > But, it only affects the direct nodes written after the last checkpoint. > We simply expect that user would change kernel versions back and forth after > stable checkpoint. With it, tests/generic/050 of fstest will fail: setting device read-only mounting filesystem that needs recovery on a read-only device: mount: SCRATCH_DEV is write-protected, mounting read-only -mount: cannot mount SCRATCH_DEV read-only unmounting read-only filesystem -umount: SCRATCH_DEV: not mounted mounting filesystem with -o norecovery on a read-only device: Could you have a look at it? Thanks,
Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery
On Tue, Sep 20, 2016 at 11:48:24PM +0800, Chao Yu wrote: > Hi Jaegeuk, > > On 2016/9/20 10:55, Jaegeuk Kim wrote: > > Previously, we used cp_version only to detect recoverable dnodes. > > In order to avoid same garbage cp_version, we needed to truncate the next > > dnode during checkpoint, resulting in additional discard or data write. > > If we can distinguish this by using crc in addition to cp_version, we can > > remove this overhead. > > > > There is backward compatibility concern where it changes node_footer layout. > > But, it only affects the direct nodes written after the last checkpoint. > > We simply expect that user would change kernel versions back and forth after > > stable checkpoint. > > With it, tests/generic/050 of fstest will fail: > > setting device read-only > mounting filesystem that needs recovery on a read-only device: > mount: SCRATCH_DEV is write-protected, mounting read-only > -mount: cannot mount SCRATCH_DEV read-only > unmounting read-only filesystem > -umount: SCRATCH_DEV: not mounted > mounting filesystem with -o norecovery on a read-only device: > > Could you have a look at it? Confirmed. There was a bug in the retrial path of fill_super(). I'm testing with this patch without any failure. Thanks, >From 2536ed279d3675549c5efe5747bf56b08a4e7070 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Mon, 19 Sep 2016 17:55:10 -0700 Subject: [PATCH] f2fs: use crc and cp version to determine roll-forward recovery Previously, we used cp_version only to detect recoverable dnodes. In order to avoid same garbage cp_version, we needed to truncate the next dnode during checkpoint, resulting in additional discard or data write. If we can distinguish this by using crc in addition to cp_version, we can remove this overhead. There is backward compatibility concern where it changes node_footer layout. But, it only affects the direct nodes written after the last checkpoint. We simply expect that user would change kernel versions back and forth after stable checkpoint. Signed-off-by: Jaegeuk Kim --- fs/f2fs/checkpoint.c | 18 - fs/f2fs/f2fs.h | 1 - fs/f2fs/node.h | 73 fs/f2fs/recovery.c | 36 +- fs/f2fs/segment.c| 22 fs/f2fs/super.c | 5 +++- 6 files changed, 55 insertions(+), 100 deletions(-) diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index df56a43..6ecc5b8 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -992,7 +992,6 @@ static void wait_on_all_pages_writeback(struct f2fs_sb_info *sbi) static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) { struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); - struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE); struct f2fs_nm_info *nm_i = NM_I(sbi); unsigned long orphan_num = sbi->im[ORPHAN_INO].ino_num; nid_t last_nid = nm_i->next_scan_nid; @@ -1001,19 +1000,10 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) __u32 crc32 = 0; int i; int cp_payload_blks = __cp_payload(sbi); - block_t discard_blk = NEXT_FREE_BLKADDR(sbi, curseg); - bool invalidate = false; struct super_block *sb = sbi->sb; struct curseg_info *seg_i = CURSEG_I(sbi, CURSEG_HOT_NODE); u64 kbytes_written; - /* -* This avoids to conduct wrong roll-forward operations and uses -* metapages, so should be called prior to sync_meta_pages below. -*/ - if (!test_opt(sbi, LFS) && discard_next_dnode(sbi, discard_blk)) - invalidate = true; - /* Flush all the NAT/SIT pages */ while (get_pages(sbi, F2FS_DIRTY_META)) { sync_meta_pages(sbi, META, LONG_MAX); @@ -1154,14 +1144,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) /* wait for previous submitted meta pages writeback */ wait_on_all_pages_writeback(sbi); - /* -* invalidate meta page which is used temporarily for zeroing out -* block at the end of warm node chain. -*/ - if (invalidate) - invalidate_mapping_pages(META_MAPPING(sbi), discard_blk, - discard_blk); - release_ino_entry(sbi, false); if (unlikely(f2fs_cp_error(sbi))) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 132756c..a472191 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2065,7 +2065,6 @@ void refresh_sit_entry(struct f2fs_sb_info *, block_t, block_t); void f2fs_wait_all_discard_bio(struct f2fs_sb_info *); void clear_prefree_segments(struct f2fs_sb_info *, struct cp_control *); void release_discard_addrs(struct f2fs_sb_info *); -bool discard_next_dnode(struct f2fs_sb_info *, block_t); int npages_for_summary_flush(struct f2fs_sb_info *, bool); void allocate_new_seg