dm-kcopyd.h 2.0 KB

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  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. #ifndef _LINUX_DM_KCOPYD_H
  12. #define _LINUX_DM_KCOPYD_H
  13. #ifdef __KERNEL__
  14. #include <linux/dm-io.h>
  15. /* FIXME: make this configurable */
  16. #define DM_KCOPYD_MAX_REGIONS 8
  17. #define DM_KCOPYD_IGNORE_ERROR 1
  18. /*
  19. * To use kcopyd you must first create a dm_kcopyd_client object.
  20. */
  21. struct dm_kcopyd_client;
  22. struct dm_kcopyd_client *dm_kcopyd_client_create(void);
  23. void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
  24. /*
  25. * Submit a copy job to kcopyd. This is built on top of the
  26. * previous three fns.
  27. *
  28. * read_err is a boolean,
  29. * write_err is a bitset, with 1 bit for each destination region
  30. */
  31. typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
  32. void *context);
  33. int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
  34. unsigned num_dests, struct dm_io_region *dests,
  35. unsigned flags, dm_kcopyd_notify_fn fn, void *context);
  36. /*
  37. * Prepare a callback and submit it via the kcopyd thread.
  38. *
  39. * dm_kcopyd_prepare_callback allocates a callback structure and returns it.
  40. * It must not be called from interrupt context.
  41. * The returned value should be passed into dm_kcopyd_do_callback.
  42. *
  43. * dm_kcopyd_do_callback submits the callback.
  44. * It may be called from interrupt context.
  45. * The callback is issued from the kcopyd thread.
  46. */
  47. void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
  48. dm_kcopyd_notify_fn fn, void *context);
  49. void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err);
  50. int dm_kcopyd_zero(struct dm_kcopyd_client *kc,
  51. unsigned num_dests, struct dm_io_region *dests,
  52. unsigned flags, dm_kcopyd_notify_fn fn, void *context);
  53. #endif /* __KERNEL__ */
  54. #endif /* _LINUX_DM_KCOPYD_H */