[PATCH v13 08/15] btrfs: dedupe: Implement btrfs_dedupe_calc_hash interface
From: Qu Wenruo <hidden>
Date: 2016-09-08 07:13:34
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
From: Wang Xiaoguang <redacted> 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 <redacted> Signed-off-by: Wang Xiaoguang <redacted> Reviewed-by: Josef Bacik <redacted> --- fs/btrfs/dedupe.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)
diff --git a/fs/btrfs/dedupe.c b/fs/btrfs/dedupe.c
index ef4968f..d0d2f8a 100644
--- a/fs/btrfs/dedupe.c
+++ b/fs/btrfs/dedupe.c@@ -639,3 +639,49 @@ 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; + SHASH_DESC_ON_STACK(sdesc, tfm); + 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->tfm = tfm; + sdesc->flags = 0; + ret = crypto_shash_init(sdesc); + if (ret) + return ret; + for (i = 0; sectorsize * i < dedupe_bs; i++) { + char *d; + + p = find_get_page(inode->i_mapping, + (start >> PAGE_SHIFT) + i); + if (WARN_ON(!p)) + return -ENOENT; + d = kmap(p); + ret = crypto_shash_update(sdesc, d, sectorsize); + kunmap(p); + put_page(p); + if (ret) + return ret; + } + ret = crypto_shash_final(sdesc, hash->hash); + return ret; +}
--
2.9.3