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 struct dm_kcopyd_client *dm_kcopyd_client_create(void); 29 void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc); 30 31 /* 32 * Submit a copy job to kcopyd. This is built on top of the 33 * previous three fns. 34 * 35 * read_err is a boolean, 36 * write_err is a bitset, with 1 bit for each destination region 37 */ 38 typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err, 39 void *context); 40 41 int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, 42 unsigned num_dests, struct dm_io_region *dests, 43 unsigned flags, dm_kcopyd_notify_fn fn, void *context); 44 45 /* 46 * Prepare a callback and submit it via the kcopyd thread. 47 * 48 * dm_kcopyd_prepare_callback allocates a callback structure and returns it. 49 * It must not be called from interrupt context. 50 * The returned value should be passed into dm_kcopyd_do_callback. 51 * 52 * dm_kcopyd_do_callback submits the callback. 53 * It may be called from interrupt context. 54 * The callback is issued from the kcopyd thread. 55 */ 56 void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, 57 dm_kcopyd_notify_fn fn, void *context); 58 void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err); 59 60 int dm_kcopyd_zero(struct dm_kcopyd_client *kc, 61 unsigned num_dests, struct dm_io_region *dests, 62 unsigned flags, dm_kcopyd_notify_fn fn, void *context); 63 64 #endif /* __KERNEL__ */ 65 #endif /* _LINUX_DM_KCOPYD_H */ 66