btrfs: resurrect btrfs_crc32c()

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.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1baa8cc395719588b85459f4558688855129f2f0..3691cd177ead09c34a0ea02d6d67e02bdd668004 100644 (file)
--- 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>
@@ -2644,6 +2645,16 @@ 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 f63dfb777e4ad954b168806ec26155f244ea2ad6..5d736d8ae3e3ed461d6684aff181430504099ab5 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1135,11 +1135,11 @@ 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 f7fe4770f0e58ea9ba5be199edf1589a95cbedbf..49edcc709a9913de4a93458eafa8d5379311bd9e 100644 (file)
--- 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,