include/linux/dm-kcopyd.h

   1 /*
   2  * Copyright (C) 2001 - 2003 Sistina Software
   3  * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
   4  *
   5  * kcopyd provides a simple interface for copying an area of one
   6  * block-device to one or more other block-devices, either synchronous
   7  * or with an asynchronous completion notification.
   8  *
   9  * This file is released under the GPL.
  10  */
  11
  12 #ifndef _LINUX_DM_KCOPYD_H
  13 #define _LINUX_DM_KCOPYD_H
  14
  15 #ifdef __KERNEL__
  16
  17 #include <linux/dm-io.h>
  18
  19 /* FIXME: make this configurable */
  20 #define DM_KCOPYD_MAX_REGIONS 8
  21
  22 #define DM_KCOPYD_IGNORE_ERROR 1
  23
  24 /*
  25  * To use kcopyd you must first create a dm_kcopyd_client object.
  26  */
  27 struct dm_kcopyd_client;
  28 int dm_kcopyd_client_create(unsigned num_pages,
  29                             struct dm_kcopyd_client **result);
  30 void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
  31
  32 /*
  33  * Submit a copy job to kcopyd.  This is built on top of the
  34  * previous three fns.
  35  *
  36  * read_err is a boolean,
  37  * write_err is a bitset, with 1 bit for each destination region
  38  */
  39 typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
  40                                     void *context);
  41
  42 int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
  43                    unsigned num_dests, struct dm_io_region *dests,
  44                    unsigned flags, dm_kcopyd_notify_fn fn, void *context);
  45
  46 #endif  /* __KERNEL__ */
  47 #endif  /* _LINUX_DM_KCOPYD_H */