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Groups > linux.kernel > #1490566 > unrolled thread
| Started by | Chao Yu <yuchao0@huawei.com> |
|---|---|
| First post | 2016-09-24 08:10 +0200 |
| Last post | 2016-09-24 20:30 +0200 |
| Articles | 2 — 2 participants |
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Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery Chao Yu <yuchao0@huawei.com> - 2016-09-24 08:10 +0200
Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery Jaegeuk Kim <jaegeuk@kernel.org> - 2016-09-24 20:30 +0200
| From | Chao Yu <yuchao0@huawei.com> |
|---|---|
| Date | 2016-09-24 08:10 +0200 |
| Subject | Re: [f2fs-dev] [PATCH 1/2] f2fs: use crc and cp version to determine roll-forward recovery |
| Message-ID | <skOjT-5Ot-7@gated-at.bofh.it> |
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,
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| From | Jaegeuk Kim <jaegeuk@kernel.org> |
|---|---|
| Date | 2016-09-24 20:30 +0200 |
| Message-ID | <skZS2-4ro-27@gated-at.bofh.it> |
| In reply to | #1490566 |
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,
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