From: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>
Unlike in-memory or on-disk dedupe method, only SHA256 hash method is
supported yet, so implement btrfs_dedupe_calc_hash() interface using
SHA256.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
Signed-off-by: Wang Xiaoguang <wangxg.f...@cn.fujitsu.com>
---
fs/btrfs/dedupe.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/fs/btrfs/dedupe.c b/fs/btrfs/dedupe.c
index 9175a5f..bdaea3a 100644
--- a/fs/btrfs/dedupe.c
+++ b/fs/btrfs/dedupe.c
@@ -593,3 +593,52 @@ int btrfs_dedupe_search(struct btrfs_fs_info *fs_info,
}
return ret;
}
+
+int btrfs_dedupe_calc_hash(struct btrfs_fs_info *fs_info,
+ struct inode *inode, u64 start,
+ struct btrfs_dedupe_hash *hash)
+{
+ int i;
+ int ret;
+ struct page *p;
+ struct btrfs_dedupe_info *dedupe_info = fs_info->dedupe_info;
+ struct crypto_shash *tfm = dedupe_info->dedupe_driver;
+ struct {
+ struct shash_desc desc;
+ char ctx[crypto_shash_descsize(tfm)];
+ } sdesc;
+ u64 dedupe_bs;
+ u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
+
+ if (!fs_info->dedupe_enabled || !hash)
+ return 0;
+
+ if (WARN_ON(dedupe_info == NULL))
+ return -EINVAL;
+
+ WARN_ON(!IS_ALIGNED(start, sectorsize));
+
+ dedupe_bs = dedupe_info->blocksize;
+
+ sdesc.desc.tfm = tfm;
+ sdesc.desc.flags = 0;
+ ret = crypto_shash_init(&sdesc.desc);
+ if (ret)
+ return ret;
+ for (i = 0; sectorsize * i < dedupe_bs; i++) {
+ char *d;
+
+ p = find_get_page(inode->i_mapping,
+ (start >> PAGE_CACHE_SHIFT) + i);
+ if (WARN_ON(!p))
+ return -ENOENT;
+ d = kmap(p);
+ ret = crypto_shash_update(&sdesc.desc, d, sectorsize);
+ kunmap(p);
+ page_cache_release(p);
+ if (ret)
+ return ret;
+ }
+ ret = crypto_shash_final(&sdesc.desc, hash->hash);
+ return ret;
+}
--
2.7.4
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
