lkml.org 
[lkml]   [2019]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [f2fs-dev] [PATCH 1/2] f2fs: allow unfixed f2fs_checkpoint.checksum_offset
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

\
 
 \ /
  Last update: 2019-04-23 22:57    [W:0.088 / U:1.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site