Ping, On 2019-6-26 17:48, Chao Yu wrote: > This original patch was from Weichao Guo. > > We may encounter both checkpoints invalid in such a case: > 1. kernel writes CP A; > 2. power-cut when kernel writes CP B, then CP B is corrupted; > 3. fsck: load CP A, fix meta/data; > 4. power-cut when fsck writes CP A in-place, then CP A is corrupted too; > > To avoid both checkpoints being invalid, this patch changes to duplicate > valid checkpoint to mirror position first, and then, write fixed checkpoint > to CP #0 position. > > This can make sure that, while fsck repairing, even there is sudden > power-cut, last valid checkpoint can be kept in CP #1 position. > > Signed-off-by: Weichao Guo <[email protected]> > Signed-off-by: Chao Yu <[email protected]> > --- > v2: > - duplicate valid CP to mirror position, update CP on #0 position. > fsck/f2fs.h | 2 ++ > fsck/fsck.c | 14 ++++++++++++-- > fsck/fsck.h | 2 ++ > fsck/mount.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++- > 4 files changed, 66 insertions(+), 3 deletions(-) > > diff --git a/fsck/f2fs.h b/fsck/f2fs.h > index 4dc6698..52e68ec 100644 > --- a/fsck/f2fs.h > +++ b/fsck/f2fs.h > @@ -195,6 +195,8 @@ struct f2fs_sb_info { > > unsigned int cur_victim_sec; /* current victim section num */ > u32 free_segments; > + > + int cp_backuped; /* backup valid checkpoint */ > }; > > static inline struct f2fs_super_block *F2FS_RAW_SUPER(struct f2fs_sb_info > *sbi) > diff --git a/fsck/fsck.c b/fsck/fsck.c > index 8953ca1..aee45d9 100644 > --- a/fsck/fsck.c > +++ b/fsck/fsck.c > @@ -2127,6 +2127,16 @@ static void fix_checkpoint(struct f2fs_sb_info *sbi) > ASSERT(ret >= 0); > } > > +static void fix_checkpoints(struct f2fs_sb_info *sbi) > +{ > + /* copy valid checkpoint to its mirror position */ > + duplicate_checkpoint(sbi); > + > + /* repair checkpoint at CP #0 position */ > + sbi->cur_cp = 1; > + fix_checkpoint(sbi); > +} > + > int check_curseg_offset(struct f2fs_sb_info *sbi, int type) > { > struct curseg_info *curseg = CURSEG_I(sbi, type); > @@ -2777,10 +2787,10 @@ int fsck_verify(struct f2fs_sb_info *sbi) > rewrite_sit_area_bitmap(sbi); > fix_curseg_info(sbi); > fix_checksum(sbi); > - fix_checkpoint(sbi); > + fix_checkpoints(sbi); > } else if (is_set_ckpt_flags(cp, CP_FSCK_FLAG) || > is_set_ckpt_flags(cp, CP_QUOTA_NEED_FSCK_FLAG)) { > - write_checkpoint(sbi); > + write_checkpoints(sbi); > } > } > return ret; > diff --git a/fsck/fsck.h b/fsck/fsck.h > index d38e8de..3699b35 100644 > --- a/fsck/fsck.h > +++ b/fsck/fsck.h > @@ -191,7 +191,9 @@ extern void flush_sit_entries(struct f2fs_sb_info *); > extern void move_curseg_info(struct f2fs_sb_info *, u64, int); > extern void write_curseg_info(struct f2fs_sb_info *); > extern int find_next_free_block(struct f2fs_sb_info *, u64 *, int, int); > +extern void duplicate_checkpoint(struct f2fs_sb_info *); > extern void write_checkpoint(struct f2fs_sb_info *); > +extern void write_checkpoints(struct f2fs_sb_info *); > extern void update_superblock(struct f2fs_super_block *, int); > extern void update_data_blkaddr(struct f2fs_sb_info *, nid_t, u16, block_t); > extern void update_nat_blkaddr(struct f2fs_sb_info *, nid_t, nid_t, block_t); > diff --git a/fsck/mount.c b/fsck/mount.c > index 60e0e4a..89f538b 100644 > --- a/fsck/mount.c > +++ b/fsck/mount.c > @@ -2229,7 +2229,7 @@ void flush_journal_entries(struct f2fs_sb_info *sbi) > int n_sits = flush_sit_journal_entries(sbi); > > if (n_nats || n_sits) > - write_checkpoint(sbi); > + write_checkpoints(sbi); > } > > void flush_sit_entries(struct f2fs_sb_info *sbi) > @@ -2478,6 +2478,45 @@ void nullify_nat_entry(struct f2fs_sb_info *sbi, u32 > nid) > free(nat_block); > } > > +void duplicate_checkpoint(struct f2fs_sb_info *sbi) > +{ > + struct f2fs_super_block *sb = F2FS_RAW_SUPER(sbi); > + unsigned long long dst, src; > + void *buf; > + unsigned int seg_size = 1 << get_sb(log_blocks_per_seg); > + int ret; > + > + if (sbi->cp_backuped) > + return; > + > + buf = malloc(F2FS_BLKSIZE * seg_size); > + ASSERT(buf); > + > + if (sbi->cur_cp == 1) { > + src = get_sb(cp_blkaddr); > + dst = src + seg_size; > + } else { > + dst = get_sb(cp_blkaddr); > + src = dst + seg_size; > + } > + > + ret = dev_read(buf, src << F2FS_BLKSIZE_BITS, seg_size); > + ASSERT(ret >= 0); > + > + ret = dev_write(buf, dst << F2FS_BLKSIZE_BITS, seg_size); > + ASSERT(ret >= 0); > + > + free(buf); > + > + ret = f2fs_fsync_device(); > + ASSERT(ret >= 0); > + > + sbi->cp_backuped = 1; > + > + MSG(0, "Info: Duplicate valid checkpoint to mirror position " > + "%llu -> %llu\n", src, dst); > +} > + > void write_checkpoint(struct f2fs_sb_info *sbi) > { > struct f2fs_checkpoint *cp = F2FS_CKPT(sbi); > @@ -2557,6 +2596,16 @@ void write_checkpoint(struct f2fs_sb_info *sbi) > ASSERT(ret >= 0); > } > > +void write_checkpoints(struct f2fs_sb_info *sbi) > +{ > + /* copy valid checkpoint to its mirror position */ > + duplicate_checkpoint(sbi); > + > + /* repair checkpoint at CP #0 position */ > + sbi->cur_cp = 1; > + write_checkpoint(sbi); > +} > + > void build_nat_area_bitmap(struct f2fs_sb_info *sbi) > { > struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA); >
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