btrfs: directly call into crypto framework for checksumming

Currently btrfs_csum_data() relied on the crc32c() wrapper around the
crypto framework for calculating the CRCs.

As we have our own crypto_shash structure in the fs_info now, we can
directly call into the crypto framework without going trough the wrapper.

This way we can even remove the btrfs_csum_data() and btrfs_csum_final()
wrappers.

The module dependency on crc32c is preserved via MODULE_SOFTDEP("pre:
crc32c"), which was previously provided by LIBCRC32C config option doing
the same.

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

9 files changed, 89 insertions, 62 deletions

diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 23537bc8c827..212b4a854f2c 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -2,7 +2,8 @@
 
 config BTRFS_FS
         tristate "Btrfs filesystem support"
-        select LIBCRC32C
+        select CRYPTO
+        select CRYPTO_CRC32C
         select ZLIB_INFLATE
         select ZLIB_DEFLATE
         select LZO_COMPRESS
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 85774e2fa3e5..81a9731959a9 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -83,7 +83,7 @@
 #include <linux/blkdev.h>
 #include <linux/mm.h>
 #include <linux/string.h>
-#include <linux/crc32c.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -1710,9 +1710,9 @@ static int btrfsic_test_for_metadata(struct btrfsic_state *state,
                                      char **datav, unsigned int num_pages)
 {
         struct btrfs_fs_info *fs_info = state->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         struct btrfs_header *h;
         u8 csum[BTRFS_CSUM_SIZE];
-        u32 crc = ~(u32)0;
         unsigned int i;
 
         if (num_pages * PAGE_SIZE < state->metablock_size)
@@ -1723,14 +1723,17 @@ static int btrfsic_test_for_metadata(struct btrfsic_state *state,
         if (memcmp(h->fsid, fs_info->fs_devices->fsid, BTRFS_FSID_SIZE))
                 return 1;
 
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
+
         for (i = 0; i < num_pages; i++) {
                 u8 *data = i ? datav[i] : (datav[i] + BTRFS_CSUM_SIZE);
                 size_t sublen = i ? PAGE_SIZE :
                                     (PAGE_SIZE - BTRFS_CSUM_SIZE);
 
-                crc = btrfs_csum_data(data, crc, sublen);
+                crypto_shash_update(shash, data, sublen);
         }
-        btrfs_csum_final(crc, csum);
+        crypto_shash_final(shash, csum);
         if (memcmp(csum, h->csum, state->csum_size))
                 return 1;
 
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 92291f266324..935c0c564c02 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/sched/mm.h>
 #include <linux/log2.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -58,29 +59,33 @@ static int check_compressed_csum(struct btrfs_inode *inode,
                                  u64 disk_start)
 {
         struct btrfs_fs_info *fs_info = inode->root->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
         int ret;
         struct page *page;
         unsigned long i;
         char *kaddr;
-        u32 csum;
+        u8 csum[BTRFS_CSUM_SIZE];
         u8 *cb_sum = cb->sums;
 
         if (inode->flags & BTRFS_INODE_NODATASUM)
                 return 0;
 
+        shash->tfm = fs_info->csum_shash;
+
         for (i = 0; i < cb->nr_pages; i++) {
                 page = cb->compressed_pages[i];
-                csum = ~(u32)0;
 
+                crypto_shash_init(shash);
                 kaddr = kmap_atomic(page);
-                csum = btrfs_csum_data(kaddr, csum, PAGE_SIZE);
-                btrfs_csum_final(csum, (u8 *)&csum);
+                crypto_shash_update(shash, kaddr, PAGE_SIZE);
                 kunmap_atomic(kaddr);
+                crypto_shash_final(shash, (u8 *)&csum);
 
                 if (memcmp(&csum, cb_sum, csum_size)) {
-                        btrfs_print_data_csum_error(inode, disk_start, csum,
-                                        *(u32 *)cb_sum, cb->mirror_num);
+                        btrfs_print_data_csum_error(inode, disk_start,
+                                                    *(u32 *)csum, *(u32 *)cb_sum,
+                                                    cb->mirror_num);
                         ret = -EIO;
                         goto fail;
                 }
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 34222bbe4b48..6c7dc24d4031 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -246,16 +246,6 @@ out:
         return em;
 }
 
-u32 btrfs_csum_data(const char *data, u32 seed, size_t len)
-{
-        return crc32c(seed, data, len);
-}
-
-void btrfs_csum_final(u32 crc, u8 *result)
-{
-        put_unaligned_le32(~crc, result);
-}
-
 /*
  * Compute the csum of a btree block and store the result to provided buffer.
  *
@@ -263,6 +253,8 @@ void btrfs_csum_final(u32 crc, u8 *result)
  */
 static int csum_tree_block(struct extent_buffer *buf, u8 *result)
 {
+        struct btrfs_fs_info *fs_info = buf->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         unsigned long len;
         unsigned long cur_len;
         unsigned long offset = BTRFS_CSUM_SIZE;
@@ -270,9 +262,12 @@ static int csum_tree_block(struct extent_buffer *buf, u8 *result)
         unsigned long map_start;
         unsigned long map_len;
         int err;
-        u32 crc = ~(u32)0;
+
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
 
         len = buf->len - offset;
+
         while (len > 0) {
                 /*
                  * Note: we don't need to check for the err == 1 case here, as
@@ -285,14 +280,13 @@ static int csum_tree_block(struct extent_buffer *buf, u8 *result)
                 if (WARN_ON(err))
                         return err;
                 cur_len = min(len, map_len - (offset - map_start));
-                crc = btrfs_csum_data(kaddr + offset - map_start,
-                                      crc, cur_len);
+                crypto_shash_update(shash, kaddr + offset - map_start, cur_len);
                 len -= cur_len;
                 offset += cur_len;
         }
         memset(result, 0, BTRFS_CSUM_SIZE);
 
-        btrfs_csum_final(crc, result);
+        crypto_shash_final(shash, result);
 
         return 0;
 }
@@ -372,17 +366,20 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
 {
         struct btrfs_super_block *disk_sb =
                 (struct btrfs_super_block *)raw_disk_sb;
-        u32 crc = ~(u32)0;
         char result[BTRFS_CSUM_SIZE];
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
 
         /*
          * The super_block structure does not span the whole
          * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space is
          * filled with zeros and is included in the checksum.
          */
-        crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
-                              crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-        btrfs_csum_final(crc, result);
+        crypto_shash_update(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
+                            BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+        crypto_shash_final(shash, result);
 
         if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
                 return 1;
@@ -3512,17 +3509,20 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 static int write_dev_supers(struct btrfs_device *device,
                             struct btrfs_super_block *sb, int max_mirrors)
 {
+        struct btrfs_fs_info *fs_info = device->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         struct buffer_head *bh;
         int i;
         int ret;
         int errors = 0;
-        u32 crc;
         u64 bytenr;
         int op_flags;
 
         if (max_mirrors == 0)
                 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
 
+        shash->tfm = fs_info->csum_shash;
+
         for (i = 0; i < max_mirrors; i++) {
                 bytenr = btrfs_sb_offset(i);
                 if (bytenr + BTRFS_SUPER_INFO_SIZE >=
@@ -3531,10 +3531,10 @@ static int write_dev_supers(struct btrfs_device *device,
 
                 btrfs_set_super_bytenr(sb, bytenr);
 
-                crc = ~(u32)0;
-                crc = btrfs_csum_data((const char *)sb + BTRFS_CSUM_SIZE, crc,
-                                      BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-                btrfs_csum_final(crc, sb->csum);
+                crypto_shash_init(shash);
+                crypto_shash_update(shash, (const char *)sb + BTRFS_CSUM_SIZE,
+                                    BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+                crypto_shash_final(shash, sb->csum);
 
                 /* One reference for us, and we leave it for the caller */
                 bh = __getblk(device->bdev, bytenr / BTRFS_BDEV_BLOCKSIZE,
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index a0161aa1ea0b..e80f7c45a307 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -115,8 +115,6 @@ int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
                           int atomic);
 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid, int level,
                       struct btrfs_key *first_key);
-u32 btrfs_csum_data(const char *data, u32 seed, size_t len);
-void btrfs_csum_final(u32 crc, u8 *result);
 blk_status_t btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
                         enum btrfs_wq_endio_type metadata);
 blk_status_t btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index de89fd1310a6..1a599f50837b 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -8,6 +8,7 @@
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
 #include <linux/sched/mm.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -432,6 +433,7 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
                        u64 file_start, int contig)
 {
         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         struct btrfs_ordered_sum *sums;
         struct btrfs_ordered_extent *ordered = NULL;
         char *data;
@@ -465,6 +467,8 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
         sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;
         index = 0;
 
+        shash->tfm = fs_info->csum_shash;
+
         bio_for_each_segment(bvec, bio, iter) {
                 if (!contig)
                         offset = page_offset(bvec.bv_page) + bvec.bv_offset;
@@ -479,8 +483,6 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
                                                  - 1);
 
                 for (i = 0; i < nr_sectors; i++) {
-                        u32 tmp;
-
                         if (offset >= ordered->file_offset + ordered->len ||
                                 offset < ordered->file_offset) {
                                 unsigned long bytes_left;
@@ -506,15 +508,13 @@ blk_status_t btrfs_csum_one_bio(struct inode *inode, struct bio *bio,
                                 index = 0;
                         }
 
-                        memset(&sums->sums[index], 0xff, csum_size);
+                        crypto_shash_init(shash);
                         data = kmap_atomic(bvec.bv_page);
-                        tmp = btrfs_csum_data(data + bvec.bv_offset
-                                                + (i * fs_info->sectorsize),
-                                                *(u32 *)&sums->sums[index],
-                                                fs_info->sectorsize);
+                        crypto_shash_update(shash, data + bvec.bv_offset
+                                            + (i * fs_info->sectorsize),
+                                            fs_info->sectorsize);
                         kunmap_atomic(data);
-                        btrfs_csum_final(tmp,
-                                        (char *)(sums->sums + index));
+                        crypto_shash_final(shash, (char *)(sums->sums + index));
                         index += csum_size;
                         offset += fs_info->sectorsize;
                         this_sum_bytes += fs_info->sectorsize;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 9137bafc9376..3d356a0f8990 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3203,23 +3203,30 @@ static int __readpage_endio_check(struct inode *inode,
                                   int icsum, struct page *page,
                                   int pgoff, u64 start, size_t len)
 {
+        struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         char *kaddr;
-        u32 csum_expected;
-        u32 csum = ~(u32)0;
+        u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
+        u8 *csum_expected;
+        u8 csum[BTRFS_CSUM_SIZE];
 
-        csum_expected = *(((u32 *)io_bio->csum) + icsum);
+        csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size;
 
         kaddr = kmap_atomic(page);
-        csum = btrfs_csum_data(kaddr + pgoff, csum,  len);
-        btrfs_csum_final(csum, (u8 *)&csum);
-        if (csum != csum_expected)
+        shash->tfm = fs_info->csum_shash;
+
+        crypto_shash_init(shash);
+        crypto_shash_update(shash, kaddr + pgoff, len);
+        crypto_shash_final(shash, csum);
+
+        if (memcmp(csum, csum_expected, csum_size))
                 goto zeroit;
 
         kunmap_atomic(kaddr);
         return 0;
 zeroit:
-        btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
-                                    io_bio->mirror_num);
+        btrfs_print_data_csum_error(BTRFS_I(inode), start, *(u32 *)csum,
+                                    *(u32 *)csum_expected, io_bio->mirror_num);
         memset(kaddr + pgoff, 1, len);
         flush_dcache_page(page);
         kunmap_atomic(kaddr);
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 0e77bffd2a5a..9f0297d529d4 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -6,6 +6,7 @@
 #include <linux/blkdev.h>
 #include <linux/ratelimit.h>
 #include <linux/sched/mm.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "volumes.h"
 #include "disk-io.h"
@@ -1787,11 +1788,12 @@ static int scrub_checksum(struct scrub_block *sblock)
 static int scrub_checksum_data(struct scrub_block *sblock)
 {
         struct scrub_ctx *sctx = sblock->sctx;
+        struct btrfs_fs_info *fs_info = sctx->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         u8 csum[BTRFS_CSUM_SIZE];
         u8 *on_disk_csum;
         struct page *page;
         void *buffer;
-        u32 crc = ~(u32)0;
         u64 len;
         int index;
 
@@ -1799,6 +1801,9 @@ static int scrub_checksum_data(struct scrub_block *sblock)
         if (!sblock->pagev[0]->have_csum)
                 return 0;
 
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
+
         on_disk_csum = sblock->pagev[0]->csum;
         page = sblock->pagev[0]->page;
         buffer = kmap_atomic(page);
@@ -1808,7 +1813,7 @@ static int scrub_checksum_data(struct scrub_block *sblock)
         for (;;) {
                 u64 l = min_t(u64, len, PAGE_SIZE);
 
-                crc = btrfs_csum_data(buffer, crc, l);
+                crypto_shash_update(shash, buffer, l);
                 kunmap_atomic(buffer);
                 len -= l;
                 if (len == 0)
@@ -1820,7 +1825,7 @@ static int scrub_checksum_data(struct scrub_block *sblock)
                 buffer = kmap_atomic(page);
         }
 
-        btrfs_csum_final(crc, csum);
+        crypto_shash_final(shash, csum);
         if (memcmp(csum, on_disk_csum, sctx->csum_size))
                 sblock->checksum_error = 1;
 
@@ -1832,16 +1837,19 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
         struct scrub_ctx *sctx = sblock->sctx;
         struct btrfs_header *h;
         struct btrfs_fs_info *fs_info = sctx->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         u8 calculated_csum[BTRFS_CSUM_SIZE];
         u8 on_disk_csum[BTRFS_CSUM_SIZE];
         struct page *page;
         void *mapped_buffer;
         u64 mapped_size;
         void *p;
-        u32 crc = ~(u32)0;
         u64 len;
         int index;
 
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
+
         BUG_ON(sblock->page_count < 1);
         page = sblock->pagev[0]->page;
         mapped_buffer = kmap_atomic(page);
@@ -1875,7 +1883,7 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
         for (;;) {
                 u64 l = min_t(u64, len, mapped_size);
 
-                crc = btrfs_csum_data(p, crc, l);
+                crypto_shash_update(shash, p, l);
                 kunmap_atomic(mapped_buffer);
                 len -= l;
                 if (len == 0)
@@ -1889,7 +1897,7 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
                 p = mapped_buffer;
         }
 
-        btrfs_csum_final(crc, calculated_csum);
+        crypto_shash_final(shash, calculated_csum);
         if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
                 sblock->checksum_error = 1;
 
@@ -1900,18 +1908,22 @@ static int scrub_checksum_super(struct scrub_block *sblock)
 {
         struct btrfs_super_block *s;
         struct scrub_ctx *sctx = sblock->sctx;
+        struct btrfs_fs_info *fs_info = sctx->fs_info;
+        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
         u8 calculated_csum[BTRFS_CSUM_SIZE];
         u8 on_disk_csum[BTRFS_CSUM_SIZE];
         struct page *page;
         void *mapped_buffer;
         u64 mapped_size;
         void *p;
-        u32 crc = ~(u32)0;
         int fail_gen = 0;
         int fail_cor = 0;
         u64 len;
         int index;
 
+        shash->tfm = fs_info->csum_shash;
+        crypto_shash_init(shash);
+
         BUG_ON(sblock->page_count < 1);
         page = sblock->pagev[0]->page;
         mapped_buffer = kmap_atomic(page);
@@ -1934,7 +1946,7 @@ static int scrub_checksum_super(struct scrub_block *sblock)
         for (;;) {
                 u64 l = min_t(u64, len, mapped_size);
 
-                crc = btrfs_csum_data(p, crc, l);
+                crypto_shash_update(shash, p, l);
                 kunmap_atomic(mapped_buffer);
                 len -= l;
                 if (len == 0)
@@ -1948,7 +1960,7 @@ static int scrub_checksum_super(struct scrub_block *sblock)
                 p = mapped_buffer;
         }
 
-        btrfs_csum_final(crc, calculated_csum);
+        crypto_shash_final(shash, calculated_csum);
         if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
                 ++fail_cor;
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 526dbae5c4cf..6e196b8a0820 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2464,3 +2464,4 @@ late_initcall(init_btrfs_fs);
 module_exit(exit_btrfs_fs)
 
 MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: crc32c");