398 строки
13 KiB
C
398 строки
13 KiB
C
/*
|
|
* Copyright (C) 2006-2009 Red Hat, Inc.
|
|
*
|
|
* This file is released under the LGPL.
|
|
*/
|
|
|
|
#ifndef __DM_LOG_USERSPACE_H__
|
|
#define __DM_LOG_USERSPACE_H__
|
|
|
|
#include <linux/dm-ioctl.h> /* For DM_UUID_LEN */
|
|
|
|
/*
|
|
* The device-mapper userspace log module consists of a kernel component and
|
|
* a user-space component. The kernel component implements the API defined
|
|
* in dm-dirty-log.h. Its purpose is simply to pass the parameters and
|
|
* return values of those API functions between kernel and user-space.
|
|
*
|
|
* Below are defined the 'request_types' - DM_ULOG_CTR, DM_ULOG_DTR, etc.
|
|
* These request types represent the different functions in the device-mapper
|
|
* dirty log API. Each of these is described in more detail below.
|
|
*
|
|
* The user-space program must listen for requests from the kernel (representing
|
|
* the various API functions) and process them.
|
|
*
|
|
* User-space begins by setting up the communication link (error checking
|
|
* removed for clarity):
|
|
* fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
|
|
* addr.nl_family = AF_NETLINK;
|
|
* addr.nl_groups = CN_IDX_DM;
|
|
* addr.nl_pid = 0;
|
|
* r = bind(fd, (struct sockaddr *) &addr, sizeof(addr));
|
|
* opt = addr.nl_groups;
|
|
* setsockopt(fd, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &opt, sizeof(opt));
|
|
*
|
|
* User-space will then wait to receive requests form the kernel, which it
|
|
* will process as described below. The requests are received in the form,
|
|
* ((struct dm_ulog_request) + (additional data)). Depending on the request
|
|
* type, there may or may not be 'additional data'. In the descriptions below,
|
|
* you will see 'Payload-to-userspace' and 'Payload-to-kernel'. The
|
|
* 'Payload-to-userspace' is what the kernel sends in 'additional data' as
|
|
* necessary parameters to complete the request. The 'Payload-to-kernel' is
|
|
* the 'additional data' returned to the kernel that contains the necessary
|
|
* results of the request. The 'data_size' field in the dm_ulog_request
|
|
* structure denotes the availability and amount of payload data.
|
|
*/
|
|
|
|
/*
|
|
* DM_ULOG_CTR corresponds to (found in dm-dirty-log.h):
|
|
* int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
|
|
* unsigned argc, char **argv);
|
|
*
|
|
* Payload-to-userspace:
|
|
* A single string containing all the argv arguments separated by ' 's
|
|
* Payload-to-kernel:
|
|
* None. ('data_size' in the dm_ulog_request struct should be 0.)
|
|
*
|
|
* The UUID contained in the dm_ulog_request structure is the reference that
|
|
* will be used by all request types to a specific log. The constructor must
|
|
* record this assotiation with instance created.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_CTR 1
|
|
|
|
/*
|
|
* DM_ULOG_DTR corresponds to (found in dm-dirty-log.h):
|
|
* void (*dtr)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* A single string containing all the argv arguments separated by ' 's
|
|
* Payload-to-kernel:
|
|
* None. ('data_size' in the dm_ulog_request struct should be 0.)
|
|
*
|
|
* The UUID contained in the dm_ulog_request structure is all that is
|
|
* necessary to identify the log instance being destroyed. There is no
|
|
* payload data.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and clearing
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_DTR 2
|
|
|
|
/*
|
|
* DM_ULOG_PRESUSPEND corresponds to (found in dm-dirty-log.h):
|
|
* int (*presuspend)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* The UUID contained in the dm_ulog_request structure is all that is
|
|
* necessary to identify the log instance being presuspended. There is no
|
|
* payload data.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_PRESUSPEND 3
|
|
|
|
/*
|
|
* DM_ULOG_POSTSUSPEND corresponds to (found in dm-dirty-log.h):
|
|
* int (*postsuspend)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* The UUID contained in the dm_ulog_request structure is all that is
|
|
* necessary to identify the log instance being postsuspended. There is no
|
|
* payload data.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_POSTSUSPEND 4
|
|
|
|
/*
|
|
* DM_ULOG_RESUME corresponds to (found in dm-dirty-log.h):
|
|
* int (*resume)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* The UUID contained in the dm_ulog_request structure is all that is
|
|
* necessary to identify the log instance being resumed. There is no
|
|
* payload data.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_RESUME 5
|
|
|
|
/*
|
|
* DM_ULOG_GET_REGION_SIZE corresponds to (found in dm-dirty-log.h):
|
|
* uint32_t (*get_region_size)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* uint64_t - contains the region size
|
|
*
|
|
* The region size is something that was determined at constructor time.
|
|
* It is returned in the payload area and 'data_size' is set to
|
|
* reflect this.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field appropriately.
|
|
*/
|
|
#define DM_ULOG_GET_REGION_SIZE 6
|
|
|
|
/*
|
|
* DM_ULOG_IS_CLEAN corresponds to (found in dm-dirty-log.h):
|
|
* int (*is_clean)(struct dm_dirty_log *log, region_t region);
|
|
*
|
|
* Payload-to-userspace:
|
|
* uint64_t - the region to get clean status on
|
|
* Payload-to-kernel:
|
|
* int64_t - 1 if clean, 0 otherwise
|
|
*
|
|
* Payload is sizeof(uint64_t) and contains the region for which the clean
|
|
* status is being made.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - filling the payload with 0 (not clean) or
|
|
* 1 (clean), setting 'data_size' and 'error' appropriately.
|
|
*/
|
|
#define DM_ULOG_IS_CLEAN 7
|
|
|
|
/*
|
|
* DM_ULOG_IN_SYNC corresponds to (found in dm-dirty-log.h):
|
|
* int (*in_sync)(struct dm_dirty_log *log, region_t region,
|
|
* int can_block);
|
|
*
|
|
* Payload-to-userspace:
|
|
* uint64_t - the region to get sync status on
|
|
* Payload-to-kernel:
|
|
* int64_t - 1 if in-sync, 0 otherwise
|
|
*
|
|
* Exactly the same as 'is_clean' above, except this time asking "has the
|
|
* region been recovered?" vs. "is the region not being modified?"
|
|
*/
|
|
#define DM_ULOG_IN_SYNC 8
|
|
|
|
/*
|
|
* DM_ULOG_FLUSH corresponds to (found in dm-dirty-log.h):
|
|
* int (*flush)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* No incoming or outgoing payload. Simply flush log state to disk.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and clearing
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_FLUSH 9
|
|
|
|
/*
|
|
* DM_ULOG_MARK_REGION corresponds to (found in dm-dirty-log.h):
|
|
* void (*mark_region)(struct dm_dirty_log *log, region_t region);
|
|
*
|
|
* Payload-to-userspace:
|
|
* uint64_t [] - region(s) to mark
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* Incoming payload contains the one or more regions to mark dirty.
|
|
* The number of regions contained in the payload can be determined from
|
|
* 'data_size/sizeof(uint64_t)'.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and clearing
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_MARK_REGION 10
|
|
|
|
/*
|
|
* DM_ULOG_CLEAR_REGION corresponds to (found in dm-dirty-log.h):
|
|
* void (*clear_region)(struct dm_dirty_log *log, region_t region);
|
|
*
|
|
* Payload-to-userspace:
|
|
* uint64_t [] - region(s) to clear
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* Incoming payload contains the one or more regions to mark clean.
|
|
* The number of regions contained in the payload can be determined from
|
|
* 'data_size/sizeof(uint64_t)'.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and clearing
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_CLEAR_REGION 11
|
|
|
|
/*
|
|
* DM_ULOG_GET_RESYNC_WORK corresponds to (found in dm-dirty-log.h):
|
|
* int (*get_resync_work)(struct dm_dirty_log *log, region_t *region);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* {
|
|
* int64_t i; -- 1 if recovery necessary, 0 otherwise
|
|
* uint64_t r; -- The region to recover if i=1
|
|
* }
|
|
* 'data_size' should be set appropriately.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field appropriately.
|
|
*/
|
|
#define DM_ULOG_GET_RESYNC_WORK 12
|
|
|
|
/*
|
|
* DM_ULOG_SET_REGION_SYNC corresponds to (found in dm-dirty-log.h):
|
|
* void (*set_region_sync)(struct dm_dirty_log *log,
|
|
* region_t region, int in_sync);
|
|
*
|
|
* Payload-to-userspace:
|
|
* {
|
|
* uint64_t - region to set sync state on
|
|
* int64_t - 0 if not-in-sync, 1 if in-sync
|
|
* }
|
|
* Payload-to-kernel:
|
|
* None.
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and clearing
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_SET_REGION_SYNC 13
|
|
|
|
/*
|
|
* DM_ULOG_GET_SYNC_COUNT corresponds to (found in dm-dirty-log.h):
|
|
* region_t (*get_sync_count)(struct dm_dirty_log *log);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* uint64_t - the number of in-sync regions
|
|
*
|
|
* No incoming payload. Kernel-bound payload contains the number of
|
|
* regions that are in-sync (in a size_t).
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_GET_SYNC_COUNT 14
|
|
|
|
/*
|
|
* DM_ULOG_STATUS_INFO corresponds to (found in dm-dirty-log.h):
|
|
* int (*status)(struct dm_dirty_log *log, STATUSTYPE_INFO,
|
|
* char *result, unsigned maxlen);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* Character string containing STATUSTYPE_INFO
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_STATUS_INFO 15
|
|
|
|
/*
|
|
* DM_ULOG_STATUS_TABLE corresponds to (found in dm-dirty-log.h):
|
|
* int (*status)(struct dm_dirty_log *log, STATUSTYPE_TABLE,
|
|
* char *result, unsigned maxlen);
|
|
*
|
|
* Payload-to-userspace:
|
|
* None.
|
|
* Payload-to-kernel:
|
|
* Character string containing STATUSTYPE_TABLE
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_STATUS_TABLE 16
|
|
|
|
/*
|
|
* DM_ULOG_IS_REMOTE_RECOVERING corresponds to (found in dm-dirty-log.h):
|
|
* int (*is_remote_recovering)(struct dm_dirty_log *log, region_t region);
|
|
*
|
|
* Payload-to-userspace:
|
|
* uint64_t - region to determine recovery status on
|
|
* Payload-to-kernel:
|
|
* {
|
|
* int64_t is_recovering; -- 0 if no, 1 if yes
|
|
* uint64_t in_sync_hint; -- lowest region still needing resync
|
|
* }
|
|
*
|
|
* When the request has been processed, user-space must return the
|
|
* dm_ulog_request to the kernel - setting the 'error' field and
|
|
* 'data_size' appropriately.
|
|
*/
|
|
#define DM_ULOG_IS_REMOTE_RECOVERING 17
|
|
|
|
/*
|
|
* (DM_ULOG_REQUEST_MASK & request_type) to get the request type
|
|
*
|
|
* Payload-to-userspace:
|
|
* A single string containing all the argv arguments separated by ' 's
|
|
* Payload-to-kernel:
|
|
* None. ('data_size' in the dm_ulog_request struct should be 0.)
|
|
*
|
|
* We are reserving 8 bits of the 32-bit 'request_type' field for the
|
|
* various request types above. The remaining 24-bits are currently
|
|
* set to zero and are reserved for future use and compatibility concerns.
|
|
*
|
|
* User-space should always use DM_ULOG_REQUEST_TYPE to aquire the
|
|
* request type from the 'request_type' field to maintain forward compatibility.
|
|
*/
|
|
#define DM_ULOG_REQUEST_MASK 0xFF
|
|
#define DM_ULOG_REQUEST_TYPE(request_type) \
|
|
(DM_ULOG_REQUEST_MASK & (request_type))
|
|
|
|
struct dm_ulog_request {
|
|
/*
|
|
* The local unique identifier (luid) and the universally unique
|
|
* identifier (uuid) are used to tie a request to a specific
|
|
* mirror log. A single machine log could probably make due with
|
|
* just the 'luid', but a cluster-aware log must use the 'uuid' and
|
|
* the 'luid'. The uuid is what is required for node to node
|
|
* communication concerning a particular log, but the 'luid' helps
|
|
* differentiate between logs that are being swapped and have the
|
|
* same 'uuid'. (Think "live" and "inactive" device-mapper tables.)
|
|
*/
|
|
uint64_t luid;
|
|
char uuid[DM_UUID_LEN];
|
|
char padding[7]; /* Padding because DM_UUID_LEN = 129 */
|
|
|
|
int32_t error; /* Used to report back processing errors */
|
|
|
|
uint32_t seq; /* Sequence number for request */
|
|
uint32_t request_type; /* DM_ULOG_* defined above */
|
|
uint32_t data_size; /* How much data (not including this struct) */
|
|
|
|
char data[0];
|
|
};
|
|
|
|
#endif /* __DM_LOG_USERSPACE_H__ */
|