On 10.05.19 г. 14:15 ч., Johannes Thumshirn wrote:
> Commit 9678c54388b6 ("btrfs: Remove custom crc32c init code") removed the
> btrfs_crc32c() function, because it was a duplicate of the crc32c() library
> function we already have in the kernel.
>
> Resurrect it as a shim wrapper over crc32c() to make following
> transformations of the checksumming code in btrfs easier.
>
> Also provide a btrfs_crc32_final() to ease following transformations.
>
> Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Mechanical patch so :
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/ctree.h | 12 ++++++++++++
> fs/btrfs/extent-tree.c | 6 +++---
> fs/btrfs/send.c | 2 +-
> 3 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index b81c331b28fa..d85541f13f65 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -19,6 +19,7 @@
> #include <linux/kobject.h>
> #include <trace/events/btrfs.h>
> #include <asm/kmap_types.h>
> +#include <asm/unaligned.h>
> #include <linux/pagemap.h>
> #include <linux/btrfs.h>
> #include <linux/btrfs_tree.h>
> @@ -2642,6 +2643,17 @@ BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cursor_right,
> ((unsigned long)(BTRFS_LEAF_DATA_OFFSET + \
> btrfs_item_offset_nr(leaf, slot)))
>
> +
> +static inline u32 btrfs_crc32c(u32 crc, const void *address, unsigned length)
> +{
> + return crc32c(crc, address, length);
> +}
> +
> +static inline void btrfs_crc32c_final(u32 crc, u8 *result)
> +{
> + put_unaligned_le32(~crc, result);
> +}
> +
> static inline u64 btrfs_name_hash(const char *name, int len)
> {
> return crc32c((u32)~1, name, len);
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index f79e477a378e..06a30f2cd2e0 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -1119,11 +1119,11 @@ static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
> __le64 lenum;
>
> lenum = cpu_to_le64(root_objectid);
> - high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
> + high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
> lenum = cpu_to_le64(owner);
> - low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
> + low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
> lenum = cpu_to_le64(offset);
> - low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
> + low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
>
> return ((u64)high_crc << 31) ^ (u64)low_crc;
> }
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index dd38dfe174df..c029ca6d5eba 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -686,7 +686,7 @@ static int send_cmd(struct send_ctx *sctx)
> hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
> hdr->crc = 0;
>
> - crc = crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
> + crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
> hdr->crc = cpu_to_le32(crc);
>
> ret = write_buf(sctx->send_filp, sctx->send_buf, sctx->send_size,
>
