f2fs: switch to using the crc32 library

Now that the crc32() library function takes advantage of
architecture-specific optimizations, it is unnecessary to go through the
crypto API.  Just use crc32().  This is much simpler, and it improves
performance due to eliminating the crypto API overhead.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20241202010844.144356-19-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

Author: ebiggers

fs/f2fs/Kconfig

@@ -4,8 +4,7 @@ config F2FS_FS
 	depends on BLOCK
 	select BUFFER_HEAD
 	select NLS
-	select CRYPTO
-	select CRYPTO_CRC32
+	select CRC32
 	select F2FS_FS_XATTR if FS_ENCRYPTION
 	select FS_ENCRYPTION_ALGS if FS_ENCRYPTION
 	select FS_IOMAP

fs/f2fs/f2fs.h

@@ -24,7 +24,6 @@
 #include <linux/quotaops.h>
 #include <linux/part_stat.h>
 #include <linux/rw_hint.h>
-#include <crypto/hash.h>
 
 #include <linux/fscrypt.h>
 #include <linux/fsverity.h>
@@ -1768,9 +1767,6 @@ struct f2fs_sb_info {
 	u64 sectors_written_start;
 	u64 kbytes_written;
 
-	/* Reference to checksum algorithm driver via cryptoapi */
-	struct crypto_shash *s_chksum_driver;
-
 	/* Precomputed FS UUID checksum for seeding other checksums */
 	__u32 s_chksum_seed;
 
@@ -1948,21 +1944,7 @@ static inline unsigned int f2fs_time_to_wait(struct f2fs_sb_info *sbi,
 static inline u32 __f2fs_crc32(struct f2fs_sb_info *sbi, u32 crc,
 			      const void *address, unsigned int length)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[4];
-	} desc;
-	int err;
-
-	BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver) != sizeof(desc.ctx));
-
-	desc.shash.tfm = sbi->s_chksum_driver;
-	*(u32 *)desc.ctx = crc;
-
-	err = crypto_shash_update(&desc.shash, address, length);
-	BUG_ON(err);
-
-	return *(u32 *)desc.ctx;
+	return crc32(crc, address, length);
 }
 
 static inline u32 f2fs_crc32(struct f2fs_sb_info *sbi, const void *address,

fs/f2fs/super.c

@@ -1694,8 +1694,6 @@ static void f2fs_put_super(struct super_block *sb)
 
 	kvfree(sbi->ckpt);
 
-	if (sbi->s_chksum_driver)
-		crypto_free_shash(sbi->s_chksum_driver);
 	kfree(sbi->raw_super);
 
 	f2fs_destroy_page_array_cache(sbi);
@@ -4466,15 +4464,6 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	}
 	mutex_init(&sbi->flush_lock);
 
-	/* Load the checksum driver */
-	sbi->s_chksum_driver = crypto_alloc_shash("crc32", 0, 0);
-	if (IS_ERR(sbi->s_chksum_driver)) {
-		f2fs_err(sbi, "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_err(sbi, "unable to set blocksize");
@@ -4919,8 +4908,6 @@ 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);
 	sb->s_fs_info = NULL;
 
@@ -5127,5 +5114,3 @@ module_exit(exit_f2fs_fs)
 MODULE_AUTHOR("Samsung Electronics's Praesto Team");
 MODULE_DESCRIPTION("Flash Friendly File System");
 MODULE_LICENSE("GPL");
-MODULE_SOFTDEP("pre: crc32");
-