Messages in this thread | | | Date | Tue, 23 Apr 2019 21:56:19 +0100 | From | Jaegeuk Kim <> | Subject | Re: [f2fs-dev] [PATCH 1/2] f2fs: allow unfixed f2fs_checkpoint.checksum_offset |
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On 04/23, Jaegeuk Kim wrote: > On 04/22, Chao Yu wrote: > > Previously, f2fs_checkpoint.checksum_offset points fixed position of > > f2fs_checkpoint structure: > > > > "#define CP_CHKSUM_OFFSET 4092" > > > > It is unnecessary, and it breaks the consecutiveness of nat and sit > > bitmap stored across checkpoint park block and payload blocks. > > > > This patch allows f2fs to handle unfixed .checksum_offset. > > > > In addition, for the case checksum value is stored in the middle of > > checkpoint park, calculating checksum value with superposition method > > like we did for inode_checksum. > > > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > > --- > > fs/f2fs/checkpoint.c | 27 +++++++++++++++++++++------ > > include/linux/f2fs_fs.h | 4 ++++ > > 2 files changed, 25 insertions(+), 6 deletions(-) > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > index 441814607b13..a25556aef8cc 100644 > > --- a/fs/f2fs/checkpoint.c > > +++ b/fs/f2fs/checkpoint.c > > @@ -794,13 +794,27 @@ static void write_orphan_inodes(struct f2fs_sb_info *sbi, block_t start_blk) > > } > > } > > > > +static __u32 f2fs_checkpoint_chksum(struct f2fs_sb_info *sbi, > > + struct f2fs_checkpoint *ckpt) > > +{ > > + unsigned int chksum_ofs = le32_to_cpu(ckpt->checksum_offset); > > + __u32 chksum; > > + > > + chksum = f2fs_crc32(sbi, ckpt, chksum_ofs); > > + if (chksum_ofs < CP_CHKSUM_OFFSET) { > > + chksum_ofs += sizeof(chksum); > > + chksum = f2fs_chksum(sbi, chksum, (__u8 *)ckpt + chksum_ofs, > > + F2FS_BLKSIZE - chksum_ofs); > > Do we need to cover __cp_payload(sbi) * blksize - chksum_ofs?
Self answer - it'd be fine to get 4KB only, since payload will be covered by entire checkpoint pack.
> > > + } > > + return chksum; > > +} > > + > > static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr, > > struct f2fs_checkpoint **cp_block, struct page **cp_page, > > unsigned long long *version) > > { > > - unsigned long blk_size = sbi->blocksize; > > size_t crc_offset = 0; > > - __u32 crc = 0; > > + __u32 crc; > > > > *cp_page = f2fs_get_meta_page(sbi, cp_addr); > > if (IS_ERR(*cp_page)) > > @@ -809,15 +823,16 @@ static int get_checkpoint_version(struct f2fs_sb_info *sbi, block_t cp_addr, > > *cp_block = (struct f2fs_checkpoint *)page_address(*cp_page); > > > > crc_offset = le32_to_cpu((*cp_block)->checksum_offset); > > - if (crc_offset > (blk_size - sizeof(__le32))) { > > + if (crc_offset < CP_MIN_CHKSUM_OFFSET || > > + crc_offset > CP_CHKSUM_OFFSET) { > > f2fs_put_page(*cp_page, 1); > > f2fs_msg(sbi->sb, KERN_WARNING, > > "invalid crc_offset: %zu", crc_offset); > > return -EINVAL; > > } > > > > - crc = cur_cp_crc(*cp_block); > > - if (!f2fs_crc_valid(sbi, crc, *cp_block, crc_offset)) { > > + crc = f2fs_checkpoint_chksum(sbi, *cp_block); > > + if (crc != cur_cp_crc(*cp_block)) { > > f2fs_put_page(*cp_page, 1); > > f2fs_msg(sbi->sb, KERN_WARNING, "invalid crc value"); > > return -EINVAL; > > @@ -1425,7 +1440,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc) > > get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP)); > > get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP)); > > > > - crc32 = f2fs_crc32(sbi, ckpt, le32_to_cpu(ckpt->checksum_offset)); > > + crc32 = f2fs_checkpoint_chksum(sbi, ckpt); > > *((__le32 *)((unsigned char *)ckpt + > > le32_to_cpu(ckpt->checksum_offset))) > > = cpu_to_le32(crc32); > > diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h > > index 55da9abed023..65559900d4d7 100644 > > --- a/include/linux/f2fs_fs.h > > +++ b/include/linux/f2fs_fs.h > > @@ -164,6 +164,10 @@ struct f2fs_checkpoint { > > unsigned char sit_nat_version_bitmap[1]; > > } __packed; > > > > +#define CP_CHKSUM_OFFSET 4092 /* default chksum offset in checkpoint */ > > +#define CP_MIN_CHKSUM_OFFSET \ > > + (offsetof(struct f2fs_checkpoint, sit_nat_version_bitmap)) > > + > > /* > > * For orphan inode management > > */ > > -- > > 2.18.0.rc1 > > > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
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