drivers/md/kcopyd.h

   1 /*
   2  * Copyright (C) 2001 Sistina Software
   3  *
   4  * This file is released under the GPL.
   5  *
   6  * Kcopyd provides a simple interface for copying an area of one
   7  * block-device to one or more other block-devices, with an asynchronous
   8  * completion notification.
   9  */
  10
  11 #ifndef DM_KCOPYD_H
  12 #define DM_KCOPYD_H
  13
  14 #include "dm-io.h"
  15
  16 /* FIXME: make this configurable */
  17 #define KCOPYD_MAX_REGIONS 8
  18
  19 #define KCOPYD_IGNORE_ERROR 1
  20
  21 /*
  22  * To use kcopyd you must first create a kcopyd client object.
  23  */
  24 struct kcopyd_client;
  25 int kcopyd_client_create(unsigned int num_pages, struct kcopyd_client **result);
  26 void kcopyd_client_destroy(struct kcopyd_client *kc);
  27
  28 /*
  29  * Submit a copy job to kcopyd.  This is built on top of the
  30  * previous three fns.
  31  *
  32  * read_err is a boolean,
  33  * write_err is a bitset, with 1 bit for each destination region
  34  */
  35 typedef void (*kcopyd_notify_fn)(int read_err,
  36                                  unsigned int write_err, void *context);
  37
  38 int kcopyd_copy(struct kcopyd_client *kc, struct io_region *from,
  39                 unsigned int num_dests, struct io_region *dests,
  40                 unsigned int flags, kcopyd_notify_fn fn, void *context);
  41
  42 #endif