From: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
Unlike in-memory or on-disk dedup method, only SHA256 hash method is
supported yet, so implement btrfs_dedup_calc_hash() interface using
SHA256.
Signed-off-by: Qu Wenruo <quwenruo@xxxxxxxxxxxxxx>
Signed-off-by: Wang Xiaoguang <wangxg.fnst@xxxxxxxxxxxxxx>
---
fs/btrfs/dedup.c | 43 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/fs/btrfs/dedup.c b/fs/btrfs/dedup.c
index 20749ce..f6b518a 100644
--- a/fs/btrfs/dedup.c
+++ b/fs/btrfs/dedup.c
@@ -516,3 +516,46 @@ int btrfs_dedup_search(struct btrfs_dedup_info *dedup_info,
}
return ret;
}
+
+int btrfs_dedup_calc_hash(struct btrfs_dedup_info *dedup_info,
+ struct inode *inode, u64 start,
+ struct btrfs_dedup_hash *hash)
+{
+ int i;
+ int ret;
+ struct page *p;
+ struct crypto_shash *tfm = dedup_info->dedup_driver;
+ struct {
+ struct shash_desc desc;
+ char ctx[crypto_shash_descsize(tfm)];
+ } sdesc;
+ u64 dedup_bs = dedup_info->blocksize;
+ u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
+
+ if (!dedup_info || !hash)
+ return 0;
+
+ WARN_ON(!IS_ALIGNED(start, sectorsize));
+
+ sdesc.desc.tfm = tfm;
+ sdesc.desc.flags = 0;
+ ret = crypto_shash_init(&sdesc.desc);
+ if (ret)
+ return ret;
+ for (i = 0; sectorsize * i < dedup_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;
+}
--
2.7.0
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