Btrfs: Switch to libcrc32c to avoid problems with cryptomgr on highmem machines

Signed-off-by: Chris Mason <chris.mason@oracle.com>

3 files changed, 8 insertions, 29 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1e83ad720b10..19a1d998fca7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -286,10 +286,7 @@ struct btrfs_block_group_cache {
         int cached;
 };
 
-struct crypto_hash;
-
 struct btrfs_fs_info {
-        spinlock_t hash_lock;
         struct btrfs_root *extent_root;
         struct btrfs_root *tree_root;
         struct radix_tree_root fs_roots_radix;
@@ -314,7 +311,6 @@ struct btrfs_fs_info {
         struct mutex fs_mutex;
         struct list_head trans_list;
         struct list_head dead_roots;
-        struct crypto_hash *hash_tfm;
         struct delayed_work trans_work;
         int do_barriers;
         int closing;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 15cc9ec92308..3712e946f9c8 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -19,7 +19,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
-#include <linux/crypto.h>
+#include <linux/crc32c.h>
 #include <linux/scatterlist.h>
 #include <linux/swap.h>
 #include <linux/radix-tree.h>
@@ -147,22 +147,12 @@ static int btree_get_block(struct inode *inode, sector_t iblock,
 int btrfs_csum_data(struct btrfs_root * root, char *data, size_t len,
                     char *result)
 {
-        struct scatterlist sg;
-        struct crypto_hash *tfm = root->fs_info->hash_tfm;
-        struct hash_desc desc;
-        int ret;
-
-        desc.tfm = tfm;
-        desc.flags = 0;
-        sg_init_one(&sg, data, len);
-        spin_lock_irq(&root->fs_info->hash_lock);
-        ret = crypto_hash_digest(&desc, &sg, 1, result);
-        spin_unlock_irq(&root->fs_info->hash_lock);
-        if (ret) {
-                printk("digest failed\n");
-        }
-        return ret;
+        u32 crc;
+        crc = crc32c(0, data, len);
+        memcpy(result, &crc, BTRFS_CRC32_SIZE);
+        return 0;
 }
+
 static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
                            int verify)
 {
@@ -454,14 +444,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
                sizeof(struct btrfs_key));
         insert_inode_hash(fs_info->btree_inode);
         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
-        fs_info->hash_tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC);
-        spin_lock_init(&fs_info->hash_lock);
 
-        if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
-                printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
-                err = -ENOMEM;
-                goto fail_iput;
-        }
         mutex_init(&fs_info->trans_mutex);
         mutex_init(&fs_info->fs_mutex);
 
@@ -613,7 +596,6 @@ int close_ctree(struct btrfs_root *root)
                 btrfs_block_release(fs_info->tree_root,
                                     fs_info->tree_root->node);
         btrfs_block_release(root, fs_info->sb_buffer);
-        crypto_free_hash(fs_info->hash_tfm);
         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
         iput(fs_info->btree_inode);
 
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6b455c2b3f03..23f029359688 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -607,7 +607,8 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
 
         while(count > 0) {
                 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
-                size_t write_bytes = min(count, nrptrs * PAGE_CACHE_SIZE -
+                size_t write_bytes = min(count, nrptrs *
+                                        (size_t)PAGE_CACHE_SIZE -
                                          offset);
                 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
                                         PAGE_CACHE_SHIFT;