From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- include/linux/dm-kcopyd.h | 88 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 include/linux/dm-kcopyd.h (limited to 'include/linux/dm-kcopyd.h') diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h new file mode 100644 index 000000000..f486d636b --- /dev/null +++ b/include/linux/dm-kcopyd.h @@ -0,0 +1,88 @@ +/* + * Copyright (C) 2001 - 2003 Sistina Software + * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved. + * + * kcopyd provides a simple interface for copying an area of one + * block-device to one or more other block-devices, either synchronous + * or with an asynchronous completion notification. + * + * This file is released under the GPL. + */ + +#ifndef _LINUX_DM_KCOPYD_H +#define _LINUX_DM_KCOPYD_H + +#ifdef __KERNEL__ + +#include + +/* FIXME: make this configurable */ +#define DM_KCOPYD_MAX_REGIONS 8 + +#define DM_KCOPYD_IGNORE_ERROR 1 + +struct dm_kcopyd_throttle { + unsigned throttle; + unsigned num_io_jobs; + unsigned io_period; + unsigned total_period; + unsigned last_jiffies; +}; + +/* + * kcopyd clients that want to support throttling must pass an initialised + * dm_kcopyd_throttle struct into dm_kcopyd_client_create(). + * Two or more clients may share the same instance of this struct between + * them if they wish to be throttled as a group. + * + * This macro also creates a corresponding module parameter to configure + * the amount of throttling. + */ +#define DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(name, description) \ +static struct dm_kcopyd_throttle dm_kcopyd_throttle = { 100, 0, 0, 0, 0 }; \ +module_param_named(name, dm_kcopyd_throttle.throttle, uint, 0644); \ +MODULE_PARM_DESC(name, description) + +/* + * To use kcopyd you must first create a dm_kcopyd_client object. + * throttle can be NULL if you don't want any throttling. + */ +struct dm_kcopyd_client; +struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle); +void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc); + +/* + * Submit a copy job to kcopyd. This is built on top of the + * previous three fns. + * + * read_err is a boolean, + * write_err is a bitset, with 1 bit for each destination region + */ +typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err, + void *context); + +int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, + unsigned num_dests, struct dm_io_region *dests, + unsigned flags, dm_kcopyd_notify_fn fn, void *context); + +/* + * Prepare a callback and submit it via the kcopyd thread. + * + * dm_kcopyd_prepare_callback allocates a callback structure and returns it. + * It must not be called from interrupt context. + * The returned value should be passed into dm_kcopyd_do_callback. + * + * dm_kcopyd_do_callback submits the callback. + * It may be called from interrupt context. + * The callback is issued from the kcopyd thread. + */ +void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc, + dm_kcopyd_notify_fn fn, void *context); +void dm_kcopyd_do_callback(void *job, int read_err, unsigned long write_err); + +int dm_kcopyd_zero(struct dm_kcopyd_client *kc, + unsigned num_dests, struct dm_io_region *dests, + unsigned flags, dm_kcopyd_notify_fn fn, void *context); + +#endif /* __KERNEL__ */ +#endif /* _LINUX_DM_KCOPYD_H */ -- cgit v1.2.3