f2fs: use cryptoapi crc32 functions

The crc function is done bit by bit.
Optimize this by use cryptoapi
crc32 function which is backed by h/w acceleration.
Signed-off-by: Keith Mok <ek9852@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/Kconfig

 config F2FS_FS
 	tristate "F2FS filesystem support"
 	depends on BLOCK
+	select CRYPTO
+	select CRYPTO_CRC32
 	help
 	  F2FS is based on Log-structured File System (LFS), which supports
 	  versatile "flash-friendly" features. The design has been focused on

fs/f2fs/checkpoint.c

@@ -635,7 +635,7 @@ static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
 		goto invalid_cp1;
 
 	crc = le32_to_cpu(*((__le32 *)((unsigned char *)cp_block + crc_offset)));
-	if (!f2fs_crc_valid(crc, cp_block, crc_offset))
+	if (!f2fs_crc_valid(sbi, crc, cp_block, crc_offset))
 		goto invalid_cp1;
 
 	pre_version = cur_cp_version(cp_block);
@@ -650,7 +650,7 @@ static struct page *validate_checkpoint(struct f2fs_sb_info *sbi,
 		goto invalid_cp2;
 
 	crc = le32_to_cpu(*((__le32 *)((unsigned char *)cp_block + crc_offset)));
-	if (!f2fs_crc_valid(crc, cp_block, crc_offset))
+	if (!f2fs_crc_valid(sbi, crc, cp_block, crc_offset))
 		goto invalid_cp2;
 
 	cur_version = cur_cp_version(cp_block);
@@ -1029,7 +1029,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
 	get_sit_bitmap(sbi, __bitmap_ptr(sbi, SIT_BITMAP));
 	get_nat_bitmap(sbi, __bitmap_ptr(sbi, NAT_BITMAP));
 
-	crc32 = f2fs_crc32(ckpt, le32_to_cpu(ckpt->checksum_offset));
+	crc32 = f2fs_crc32(sbi, ckpt, le32_to_cpu(ckpt->checksum_offset));
 	*((__le32 *)((unsigned char *)ckpt +
 				le32_to_cpu(ckpt->checksum_offset)))
 				= cpu_to_le32(crc32);

fs/f2fs/f2fs.h

@@ -23,6 +23,7 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/fscrypto.h>
+#include <crypto/hash.h>
 
 #ifdef CONFIG_F2FS_CHECK_FS
 #define f2fs_bug_on(sbi, condition)	BUG_ON(condition)
@@ -83,27 +84,6 @@ struct f2fs_mount_info {
 #define F2FS_CLEAR_FEATURE(sb, mask)					\
 	F2FS_SB(sb)->raw_super->feature &= ~cpu_to_le32(mask)
 
-#define CRCPOLY_LE 0xedb88320
-
-static inline __u32 f2fs_crc32(void *buf, size_t len)
-{
-	unsigned char *p = (unsigned char *)buf;
-	__u32 crc = F2FS_SUPER_MAGIC;
-	int i;
-
-	while (len--) {
-		crc ^= *p++;
-		for (i = 0; i < 8; i++)
-			crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
-	}
-	return crc;
-}
-
-static inline bool f2fs_crc_valid(__u32 blk_crc, void *buf, size_t buf_size)
-{
-	return f2fs_crc32(buf, buf_size) == blk_crc;
-}
-
 /*
  * For checkpoint manager
  */
@@ -819,6 +799,9 @@ struct f2fs_sb_info {
 	/* For write statistics */
 	u64 sectors_written_start;
 	u64 kbytes_written;
+
+	/* Reference to checksum algorithm driver via cryptoapi */
+	struct crypto_shash *s_chksum_driver;
 };
 
 /* For write statistics. Suppose sector size is 512 bytes,
@@ -856,6 +839,29 @@ static inline bool is_idle(struct f2fs_sb_info *sbi)
 /*
  * Inline functions
  */
+static inline u32 f2fs_crc32(struct f2fs_sb_info *sbi, const void *address,
+			   unsigned int length)
+{
+	SHASH_DESC_ON_STACK(shash, sbi->s_chksum_driver);
+	u32 *ctx = (u32 *)shash_desc_ctx(shash);
+	int err;
+
+	shash->tfm = sbi->s_chksum_driver;
+	shash->flags = 0;
+	*ctx = F2FS_SUPER_MAGIC;
+
+	err = crypto_shash_update(shash, address, length);
+	BUG_ON(err);
+
+	return *ctx;
+}
+
+static inline bool f2fs_crc_valid(struct f2fs_sb_info *sbi, __u32 blk_crc,
+				  void *buf, size_t buf_size)
+{
+	return f2fs_crc32(sbi, buf, buf_size) == blk_crc;
+}
+
 static inline struct f2fs_inode_info *F2FS_I(struct inode *inode)
 {
 	return container_of(inode, struct f2fs_inode_info, vfs_inode);

fs/f2fs/super.c

@@ -590,6 +590,8 @@ static void f2fs_put_super(struct super_block *sb)
 	wait_for_completion(&sbi->s_kobj_unregister);
 
 	sb->s_fs_info = NULL;
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi->raw_super);
 	kfree(sbi);
 }
@@ -1310,6 +1312,15 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	if (!sbi)
 		return -ENOMEM;
 
+	/* Load the checksum driver */
+	sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
+	if (IS_ERR(sbi->s_chksum_driver)) {
+		f2fs_msg(sb, KERN_ERR, "Cannot load crc32 driver.");
+		err = PTR_ERR(sbi->s_chksum_driver);
+		sbi->s_chksum_driver = NULL;
+		goto free_sbi;
+	}
+
 	/* set a block size */
 	if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
 		f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
@@ -1568,6 +1579,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 free_sb_buf:
 	kfree(raw_super);
 free_sbi:
+	if (sbi->s_chksum_driver)
+		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi);
 
 	/* give only one another chance */