[PATCH 2/2] btrfs: Remove custom crc32c init code

From: Nikolay Borisov
Date: Mon Jan 08 2018 - 04:45:50 EST

The custom crc32 init code was introduced in
14a958e678cd ("Btrfs: fix btrfs boot when compiled as built-in") to
enable using btrfs as a built-in. However, later as pointed out by
60efa5eb2e88 ("Btrfs: use late_initcall instead of module_init") this
wasn't enough and finally btrfs was switched to late_initcall which
comes after the generic crc32c implementation is initiliased. The
latter commit superseeded the former. Now that we don't have to
maintain our own code let's just remove it and switch to using the
generic implementation.

Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
---

Despite touching a lot of files the patch is really simple. Here is the gist
of the changes:

1. Select LIBCRC32C rather than the low-level modules.
2. s/btrfs_crc32c/crc32c/g
3. replace hash.h with linux/crc32c.h
4. Move the btrfs namehash funcs to ctree.h and change the tree accordingly.

I've tested this with btrfs being both a module and a built-in and xfstest
doesn't complain.

fs/btrfs/Kconfig | 3 +--
fs/btrfs/Makefile | 2 +-
fs/btrfs/check-integrity.c | 4 ++--
fs/btrfs/ctree.h | 16 ++++++++++++++
fs/btrfs/dir-item.c | 1 -
fs/btrfs/disk-io.c | 4 ++--
fs/btrfs/extent-tree.c | 10 ++++-----
fs/btrfs/hash.c | 54 ----------------------------------------------
fs/btrfs/hash.h | 43 ------------------------------------
fs/btrfs/inode-item.c | 1 -
fs/btrfs/inode.c | 1 -
fs/btrfs/props.c | 2 +-
fs/btrfs/send.c | 4 ++--
fs/btrfs/super.c | 14 ++++--------
fs/btrfs/tree-log.c | 2 +-
15 files changed, 35 insertions(+), 126 deletions(-)
delete mode 100644 fs/btrfs/hash.c
delete mode 100644 fs/btrfs/hash.h

diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 2e558227931a..4c2dadd8fd8d 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -1,7 +1,6 @@
config BTRFS_FS
tristate "Btrfs filesystem support"
- select CRYPTO
- select CRYPTO_CRC32C
+ select LIBCRC32C
select ZLIB_INFLATE
select ZLIB_DEFLATE
select LZO_COMPRESS
diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 6fe881d5cb38..9cebe5366b35 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -10,7 +10,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
export.o tree-log.o free-space-cache.o zlib.o lzo.o zstd.o \
compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
- uuid-tree.o props.o hash.o free-space-tree.o tree-checker.o
+ uuid-tree.o props.o free-space-tree.o tree-checker.o

btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 7d51b5a5b505..3baebbc021c5 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -96,9 +96,9 @@
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/string.h>
+#include <linux/crc32c.h>
#include "ctree.h"
#include "disk-io.h"
-#include "hash.h"
#include "transaction.h"
#include "extent_io.h"
#include "volumes.h"
@@ -1736,7 +1736,7 @@ static int btrfsic_test_for_metadata(struct btrfsic_state *state,
size_t sublen = i ? PAGE_SIZE :
(PAGE_SIZE - BTRFS_CSUM_SIZE);

- crc = btrfs_crc32c(crc, data, sublen);
+ crc = crc32c(crc, data, sublen);
}
btrfs_csum_final(crc, csum);
if (memcmp(csum, h->csum, state->csum_size))
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 13c260b525a1..120a17b958eb 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -40,6 +40,7 @@
#include <linux/sizes.h>
#include <linux/dynamic_debug.h>
#include <linux/refcount.h>
+#include <linux/crc32c.h>
#include "extent_io.h"
#include "extent_map.h"
#include "async-thread.h"
@@ -98,6 +99,7 @@ static const int btrfs_csum_sizes[] = { 4 };

#define BTRFS_MAX_EXTENT_SIZE SZ_128M

+
/*
* Count how many BTRFS_MAX_EXTENT_SIZE cover the @size
*/
@@ -2555,6 +2557,20 @@ BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cursor_right,
((unsigned long)(BTRFS_LEAF_DATA_OFFSET + \
btrfs_item_offset_nr(leaf, slot)))

+static inline u64 btrfs_name_hash(const char *name, int len)
+{
+ return crc32c((u32)~1, name, len);
+}
+
+/*
+ * Figure the key offset of an extended inode ref
+ */
+static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
+ int len)
+{
+ return (u64) crc32c(parent_objectid, name, len);
+}
+
static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
{
return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 41cb9196eaa8..176143d26d47 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -18,7 +18,6 @@

#include "ctree.h"
#include "disk-io.h"
-#include "hash.h"
#include "transaction.h"

/*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a8ecccfc36de..207407474fa5 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -30,10 +30,10 @@
#include <linux/ratelimit.h>
#include <linux/uuid.h>
#include <linux/semaphore.h>
+#include <linux/crc32c.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "disk-io.h"
-#include "hash.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "volumes.h"
@@ -268,7 +268,7 @@ static struct extent_map *btree_get_extent(struct btrfs_inode *inode,

u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
{
- return btrfs_crc32c(seed, data, len);
+ return crc32c(seed, data, len);
}

void btrfs_csum_final(u32 crc, u8 *result)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 22cb3bd315df..848baf7d56d7 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -27,7 +27,7 @@
#include <linux/ratelimit.h>
#include <linux/percpu_counter.h>
#include <linux/lockdep.h>
-#include "hash.h"
+#include <linux/crc32c.h>
#include "tree-log.h"
#include "disk-io.h"
#include "print-tree.h"
@@ -1203,11 +1203,11 @@ static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset)
__le64 lenum;

lenum = cpu_to_le64(root_objectid);
- high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum));
+ high_crc = crc32c(high_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(owner);
- low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
+ low_crc = crc32c(low_crc, &lenum, sizeof(lenum));
lenum = cpu_to_le64(offset);
- low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum));
+ low_crc = crc32c(low_crc, &lenum, sizeof(lenum));

return ((u64)high_crc << 31) ^ (u64)low_crc;
}
@@ -5950,7 +5950,7 @@ int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
*/
u64 num_bytes = btrfs_calc_trans_metadata_size(fs_info, 1);

- trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
+ trace_btrfs_space_reservation(fs_info, "orphan", btrfs_ino(inode),
num_bytes, 1);
return btrfs_block_rsv_migrate(src_rsv, dst_rsv, num_bytes, 1);
}
diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
deleted file mode 100644
index baacc1866861..000000000000
--- a/fs/btrfs/hash.c
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@xxxxxxxxx>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- */
-
-#include <crypto/hash.h>
-#include <linux/err.h>
-#include "hash.h"
-
-static struct crypto_shash *tfm;
-
-int __init btrfs_hash_init(void)
-{
- tfm = crypto_alloc_shash("crc32c", 0, 0);
-
- return PTR_ERR_OR_ZERO(tfm);
-}
-
-const char* btrfs_crc32c_impl(void)
-{
- return crypto_tfm_alg_driver_name(crypto_shash_tfm(tfm));
-}
-
-void btrfs_hash_exit(void)
-{
- crypto_free_shash(tfm);
-}
-
-u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
-{
- SHASH_DESC_ON_STACK(shash, tfm);
- u32 *ctx = (u32 *)shash_desc_ctx(shash);
- u32 retval;
- int err;
-
- shash->tfm = tfm;
- shash->flags = 0;
- *ctx = crc;
-
- err = crypto_shash_update(shash, address, length);
- BUG_ON(err);
-
- retval = *ctx;
- barrier_data(ctx);
- return retval;
-}
diff --git a/fs/btrfs/hash.h b/fs/btrfs/hash.h
deleted file mode 100644
index c3a2ec554361..000000000000
--- a/fs/btrfs/hash.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
- * Copyright (C) 2007 Oracle. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License v2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- */
-
-#ifndef __HASH__
-#define __HASH__
-
-int __init btrfs_hash_init(void);
-
-void btrfs_hash_exit(void);
-const char* btrfs_crc32c_impl(void);
-
-u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length);
-
-static inline u64 btrfs_name_hash(const char *name, int len)
-{
- return btrfs_crc32c((u32)~1, name, len);
-}
-
-/*
- * Figure the key offset of an extended inode ref
- */
-static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
- int len)
-{
- return (u64) btrfs_crc32c(parent_objectid, name, len);
-}
-
-#endif
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 39c968f80157..83f85f074307 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -18,7 +18,6 @@

#include "ctree.h"
#include "disk-io.h"
-#include "hash.h"
#include "transaction.h"
#include "print-tree.h"

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c2a6918eca5e..36fac11b779e 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -57,7 +57,6 @@
#include "free-space-cache.h"
#include "inode-map.h"
#include "backref.h"
-#include "hash.h"
#include "props.h"
#include "qgroup.h"
#include "dedupe.h"
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index f6a05f836629..a78a7e32a124 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -19,8 +19,8 @@
#include <linux/hashtable.h>
#include "props.h"
#include "btrfs_inode.h"
-#include "hash.h"
#include "transaction.h"
+#include "ctree.h"
#include "xattr.h"
#include "compression.h"

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 20d3300bd268..a4230e370c06 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -27,10 +27,10 @@
#include <linux/vmalloc.h>
#include <linux/string.h>
#include <linux/compat.h>
+#include <linux/crc32c.h>

#include "send.h"
#include "backref.h"
-#include "hash.h"
#include "locking.h"
#include "disk-io.h"
#include "btrfs_inode.h"
@@ -695,7 +695,7 @@ static int send_cmd(struct send_ctx *sctx)
hdr->len = cpu_to_le32(sctx->send_size - sizeof(*hdr));
hdr->crc = 0;

- crc = btrfs_crc32c(0, (unsigned char *)sctx->send_buf, sctx->send_size);
+ crc = 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,
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3a4dce153645..f33a55272deb 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -41,6 +41,7 @@
#include <linux/slab.h>
#include <linux/cleancache.h>
#include <linux/ratelimit.h>
+#include <linux/crc32c.h>
#include <linux/btrfs.h>
#include "delayed-inode.h"
#include "ctree.h"
@@ -48,7 +49,6 @@
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
-#include "hash.h"
#include "props.h"
#include "xattr.h"
#include "volumes.h"
@@ -2350,22 +2350,18 @@ static void btrfs_print_mod_info(void)
", ref-verify=on"
#endif
"\n",
- btrfs_crc32c_impl());
+ crc32c_impl());
}

static int __init init_btrfs_fs(void)
{
int err;

- err = btrfs_hash_init();
- if (err)
- return err;
-
btrfs_props_init();

err = btrfs_init_sysfs();
if (err)
- goto free_hash;
+ return err;

btrfs_init_compress();

@@ -2446,8 +2442,7 @@ static int __init init_btrfs_fs(void)
free_compress:
btrfs_exit_compress();
btrfs_exit_sysfs();
-free_hash:
- btrfs_hash_exit();
+
return err;
}

@@ -2467,7 +2462,6 @@ static void __exit exit_btrfs_fs(void)
btrfs_exit_sysfs();
btrfs_cleanup_fs_uuids();
btrfs_exit_compress();
- btrfs_hash_exit();
}

late_initcall(init_btrfs_fs);
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 7bf9b31561db..5dee3acdca72 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -20,12 +20,12 @@
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/list_sort.h>
+#include "ctree.h"
#include "tree-log.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "backref.h"
-#include "hash.h"
#include "compression.h"
#include "qgroup.h"

--
2.7.4