btrfs: add boilerplate code for directly including the crypto framework

Add boilerplate code for directly including the crypto framework.  This
helps us flipping the switch for new algorithms.

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 a66ed58058d94731c6c6be1f24d73d1688b484be..2e908c557fb258969db5afc01c72b748ebcea3fe 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -73,6 +73,7 @@ struct btrfs_ref;
 
 /* four bytes for CRC32 */
 static const int btrfs_csum_sizes[] = { 4 };
+static const char *btrfs_csum_names[] = { "crc32c" };
 
 #define BTRFS_EMPTY_DIR_SIZE 0
 
@@ -1163,6 +1164,8 @@ struct btrfs_fs_info {
        spinlock_t swapfile_pins_lock;
        struct rb_root swapfile_pins;
 
+       struct crypto_shash *csum_shash;
+
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
        spinlock_t ref_verify_lock;
        struct rb_root block_tree;
@@ -2454,6 +2457,11 @@ static inline int btrfs_super_csum_size(const struct btrfs_super_block *s)
        return btrfs_csum_sizes[t];
 }
 
+static inline const char *btrfs_super_csum_name(u16 csum_type)
+{
+       /* csum type is validated at mount time */
+       return btrfs_csum_names[csum_type];
+}
 
 /*
  * The leaf data grows from end-to-front in the node.

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c9ce0b0020084e336a1f99b8e623a5bfe9f8404f..34222bbe4b482fb2cfecd8a977ee97415c34d43e 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -19,6 +19,7 @@
 #include <linux/crc32c.h>
 #include <linux/sched/mm.h>
 #include <asm/unaligned.h>
+#include <crypto/hash.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -2256,6 +2257,29 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
        return 0;
 }
 
+static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
+{
+       struct crypto_shash *csum_shash;
+       const char *csum_name = btrfs_super_csum_name(csum_type);
+
+       csum_shash = crypto_alloc_shash(csum_name, 0, 0);
+
+       if (IS_ERR(csum_shash)) {
+               btrfs_err(fs_info, "error allocating %s hash for checksum",
+                         csum_name);
+               return PTR_ERR(csum_shash);
+       }
+
+       fs_info->csum_shash = csum_shash;
+
+       return 0;
+}
+
+static void btrfs_free_csum_hash(struct btrfs_fs_info *fs_info)
+{
+       crypto_free_shash(fs_info->csum_shash);
+}
+
 static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
                            struct btrfs_fs_devices *fs_devices)
 {
@@ -2820,6 +2844,12 @@ int open_ctree(struct super_block *sb,
                goto fail_alloc;
        }
 
+       ret = btrfs_init_csum_hash(fs_info, csum_type);
+       if (ret) {
+               err = ret;
+               goto fail_alloc;
+       }
+
        /*
         * We want to check superblock checksum, the type is stored inside.
         * Pass the whole disk block of size BTRFS_SUPER_INFO_SIZE (4k).
@@ -2828,7 +2858,7 @@ int open_ctree(struct super_block *sb,
                btrfs_err(fs_info, "superblock checksum mismatch");
                err = -EINVAL;
                brelse(bh);
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        /*
@@ -2865,11 +2895,11 @@ int open_ctree(struct super_block *sb,
        if (ret) {
                btrfs_err(fs_info, "superblock contains fatal errors");
                err = -EINVAL;
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        if (!btrfs_super_root(disk_super))
-               goto fail_alloc;
+               goto fail_csum;
 
        /* check FS state, whether FS is broken. */
        if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_ERROR)
@@ -2891,7 +2921,7 @@ int open_ctree(struct super_block *sb,
        ret = btrfs_parse_options(fs_info, options, sb->s_flags);
        if (ret) {
                err = ret;
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        features = btrfs_super_incompat_flags(disk_super) &
@@ -2901,7 +2931,7 @@ int open_ctree(struct super_block *sb,
                    "cannot mount because of unsupported optional features (%llx)",
                    features);
                err = -EINVAL;
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        features = btrfs_super_incompat_flags(disk_super);
@@ -2945,7 +2975,7 @@ int open_ctree(struct super_block *sb,
                btrfs_err(fs_info,
 "unequal nodesize/sectorsize (%u != %u) are not allowed for mixed block groups",
                        nodesize, sectorsize);
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        /*
@@ -2961,7 +2991,7 @@ int open_ctree(struct super_block *sb,
        "cannot mount read-write because of unsupported optional features (%llx)",
                       features);
                err = -EINVAL;
-               goto fail_alloc;
+               goto fail_csum;
        }
 
        ret = btrfs_init_workqueues(fs_info, fs_devices);
@@ -3339,6 +3369,8 @@ fail_tree_roots:
 fail_sb_buffer:
        btrfs_stop_all_workers(fs_info);
        btrfs_free_block_groups(fs_info);
+fail_csum:
+       btrfs_free_csum_hash(fs_info);
 fail_alloc:
 fail_iput:
        btrfs_mapping_tree_free(&fs_info->mapping_tree);