13bd94003SHeinz Mauelshagen /* SPDX-License-Identifier: GPL-2.0-only */ 2a765e20eSAlasdair G Kergon /* 3a765e20eSAlasdair G Kergon * Copyright (C) 2001 - 2003 Sistina Software 4a765e20eSAlasdair G Kergon * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved. 5a765e20eSAlasdair G Kergon * 6a765e20eSAlasdair G Kergon * kcopyd provides a simple interface for copying an area of one 7a765e20eSAlasdair G Kergon * block-device to one or more other block-devices, either synchronous 8a765e20eSAlasdair G Kergon * or with an asynchronous completion notification. 9a765e20eSAlasdair G Kergon * 10a765e20eSAlasdair G Kergon * This file is released under the GPL. 11a765e20eSAlasdair G Kergon */ 12a765e20eSAlasdair G Kergon 13a765e20eSAlasdair G Kergon #ifndef _LINUX_DM_KCOPYD_H 14a765e20eSAlasdair G Kergon #define _LINUX_DM_KCOPYD_H 15a765e20eSAlasdair G Kergon 16a765e20eSAlasdair G Kergon #ifdef __KERNEL__ 17a765e20eSAlasdair G Kergon 18a765e20eSAlasdair G Kergon #include <linux/dm-io.h> 19a765e20eSAlasdair G Kergon 20a765e20eSAlasdair G Kergon /* FIXME: make this configurable */ 21a765e20eSAlasdair G Kergon #define DM_KCOPYD_MAX_REGIONS 8 22a765e20eSAlasdair G Kergon 23a765e20eSAlasdair G Kergon #define DM_KCOPYD_IGNORE_ERROR 1 24b73c67c2SDamien Le Moal #define DM_KCOPYD_WRITE_SEQ 2 25a765e20eSAlasdair G Kergon 26df5d2e90SMikulas Patocka struct dm_kcopyd_throttle { 27*86a3238cSHeinz Mauelshagen unsigned int throttle; 28*86a3238cSHeinz Mauelshagen unsigned int num_io_jobs; 29*86a3238cSHeinz Mauelshagen unsigned int io_period; 30*86a3238cSHeinz Mauelshagen unsigned int total_period; 31*86a3238cSHeinz Mauelshagen unsigned int last_jiffies; 32df5d2e90SMikulas Patocka }; 33df5d2e90SMikulas Patocka 34df5d2e90SMikulas Patocka /* 35df5d2e90SMikulas Patocka * kcopyd clients that want to support throttling must pass an initialised 36df5d2e90SMikulas Patocka * dm_kcopyd_throttle struct into dm_kcopyd_client_create(). 37df5d2e90SMikulas Patocka * Two or more clients may share the same instance of this struct between 38df5d2e90SMikulas Patocka * them if they wish to be throttled as a group. 39df5d2e90SMikulas Patocka * 40df5d2e90SMikulas Patocka * This macro also creates a corresponding module parameter to configure 41df5d2e90SMikulas Patocka * the amount of throttling. 42df5d2e90SMikulas Patocka */ 43df5d2e90SMikulas Patocka #define DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(name, description) \ 44df5d2e90SMikulas Patocka static struct dm_kcopyd_throttle dm_kcopyd_throttle = { 100, 0, 0, 0, 0 }; \ 45df5d2e90SMikulas Patocka module_param_named(name, dm_kcopyd_throttle.throttle, uint, 0644); \ 46df5d2e90SMikulas Patocka MODULE_PARM_DESC(name, description) 47df5d2e90SMikulas Patocka 48a765e20eSAlasdair G Kergon /* 49a765e20eSAlasdair G Kergon * To use kcopyd you must first create a dm_kcopyd_client object. 50df5d2e90SMikulas Patocka * throttle can be NULL if you don't want any throttling. 51a765e20eSAlasdair G Kergon */ 52a765e20eSAlasdair G Kergon struct dm_kcopyd_client; 53df5d2e90SMikulas Patocka struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle); 54a765e20eSAlasdair G Kergon void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc); 55293128b1SMikulas Patocka void dm_kcopyd_client_flush(struct dm_kcopyd_client *kc); 56a765e20eSAlasdair G Kergon 57a765e20eSAlasdair G Kergon /* 58a765e20eSAlasdair G Kergon * Submit a copy job to kcopyd. This is built on top of the 59a765e20eSAlasdair G Kergon * previous three fns. 60a765e20eSAlasdair G Kergon * 61a765e20eSAlasdair G Kergon * read_err is a boolean, 62a765e20eSAlasdair G Kergon * write_err is a bitset, with 1 bit for each destination region 63a765e20eSAlasdair G Kergon */ 64*86a3238cSHeinz Mauelshagen typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned int long write_err, 65a765e20eSAlasdair G Kergon void *context); 66a765e20eSAlasdair G Kergon 677209049dSMike Snitzer void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, 68*86a3238cSHeinz Mauelshagen unsigned int num_dests, struct dm_io_region *dests, 69*86a3238cSHeinz Mauelshagen unsigned int flags, dm_kcopyd_notify_fn fn, void *context); 70a765e20eSAlasdair G Kergon 71a6e50b40SMikulas Patocka /* 72a6e50b40SMikulas Patocka * Prepare a callback and submit it via the kcopyd thread. 73a6e50b40SMikulas Patocka * 74a6e50b40SMikulas Patocka * dm_kcopyd_prepare_callback allocates a callback structure and returns it. 75a6e50b40SMikulas Patocka * It must not be called from interrupt context. 76a6e50b40SMikulas Patocka * The returned value should be passed into dm_kcopyd_do_callback. 77a6e50b40SMikulas Patocka * 78a6e50b40SMikulas Patocka * dm_kcopyd_do_callback submits the callback. 79a6e50b40SMikulas Patocka * It may be called from interrupt context. 80a6e50b40SMikulas Patocka * The callback is issued from the kcopyd thread. 81a6e50b40SMikulas Patocka */ 82a6e50b40SMikulas Patocka void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, 83a6e50b40SMikulas Patocka dm_kcopyd_notify_fn fn, void *context); 84*86a3238cSHeinz Mauelshagen void dm_kcopyd_do_callback(void *job, int read_err, unsigned int long write_err); 85a6e50b40SMikulas Patocka 867209049dSMike Snitzer void dm_kcopyd_zero(struct dm_kcopyd_client *kc, 87*86a3238cSHeinz Mauelshagen unsigned int num_dests, struct dm_io_region *dests, 88*86a3238cSHeinz Mauelshagen unsigned int flags, dm_kcopyd_notify_fn fn, void *context); 897f069653SMikulas Patocka 90a765e20eSAlasdair G Kergon #endif /* __KERNEL__ */ 91a765e20eSAlasdair G Kergon #endif /* _LINUX_DM_KCOPYD_H */ 92