verity: remove entry_readahead

dm-bht.h

 /*
  * Copyright (C) 2010 The Chromium OS Authors <chromium-os-dev@chromium.org>
  *
  * Device-Mapper block hash tree interface.
  * See Documentation/device-mapper/dm-bht.txt for details.
  *
  * This file is released under the GPLv2.
  */
 #ifndef __LINUX_DM_BHT_H
 #define __LINUX_DM_BHT_H
@@ skipping 71 matching lines @@
  *
  * TODO(wad): All hash storage memory is pre-allocated and freed once an
  * entire branch has been verified.
  */
 struct dm_bht {
         /* Configured values */
         /* ENFORCE: depth must be >= 2. */
         unsigned int depth;  /* Depth of the tree including the root */
         unsigned int block_count;  /* Number of blocks hashed */
         char hash_alg[CRYPTO_MAX_ALG_NAME];
-        unsigned int entry_readahead;  /* number of entries to attempt to
-                                        * pre-read in a level.
-                                        */
 
         /* Computed values */
         unsigned int node_count;  /* Data size (in hashes) for each entry */
         unsigned int node_count_shift;  /* first bit set - 1 */
         /* There is one per CPU so that verified can be simultaneous. */
         struct hash_desc *hash_desc;  /* Container for the hash alg */
         unsigned int digest_size;
         sector_t sectors;  /* Number of disk sectors used */
 
         /* bool verified;  Full tree is verified */
         u8 *root_digest;  /* hash_alg(levels[0].entries[*].nodes) */
         atomic_t root_state; /* Uses UNALLOCATED, REQUESTED, and VERIFIED */
         struct dm_bht_level *levels;  /* in reverse order */
         mempool_t *entry_pool;
         /* Callbacks for reading and/or writing to the hash device */
         dm_bht_callback read_cb;
         dm_bht_callback write_cb;
 };
 
 /* Constructor for struct dm_bht instances. */
 int dm_bht_create(struct dm_bht *bht,
                   unsigned int depth,
                   unsigned int block_count,
                   const char *alg_name);
 /* Destructor for struct dm_bht instances.  Does not free @bht */
 int dm_bht_destroy(struct dm_bht *bht);
 
 /* Basic accessors for struct dm_bht */
 sector_t dm_bht_sectors(const struct dm_bht *bht);
-void dm_bht_set_entry_readahead(struct dm_bht *bht,
-                                unsigned int readahead_count);
 void dm_bht_set_read_cb(struct dm_bht *bht, dm_bht_callback read_cb);
 void dm_bht_set_write_cb(struct dm_bht *bht, dm_bht_callback write_cb);
 int dm_bht_set_root_hexdigest(struct dm_bht *bht, const u8 *hexdigest);
 int dm_bht_root_hexdigest(struct dm_bht *bht, u8 *hexdigest, int available);
 
 /* Functions for loading in data from disk for verification */
 bool dm_bht_is_populated(struct dm_bht *bht, unsigned int block_index);
 int dm_bht_populate(struct dm_bht *bht, void *read_cb_ctx,
                     unsigned int block_index);
 int dm_bht_verify_block(struct dm_bht *bht, unsigned int block_index,
                         const void *buf);
 
 /* Functions for creating struct dm_bhts on disk.  A newly created dm_bht
  * should not be directly used for verification. (It should be repopulated.)
  * In addition, these functions aren't meant to be called in parallel.
  */
 int dm_bht_compute(struct dm_bht *bht, void *read_cb_ctx);
 int dm_bht_sync(struct dm_bht *bht, void *write_cb_ctx);
 int dm_bht_store_block(struct dm_bht *bht, unsigned int block_index,
                        u8 *block_data);
 int dm_bht_zeroread_callback(void *ctx, sector_t start, u8 *dst, sector_t count,
                              struct dm_bht_entry *entry);
 void dm_bht_read_completed(struct dm_bht_entry *entry, int status);
 void dm_bht_write_completed(struct dm_bht_entry *entry, int status);
 #endif  /* __LINUX_DM_BHT_H */