diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dm-dirty-log.h | 131 | ||||
| -rw-r--r-- | include/linux/dm-io.h | 85 | ||||
| -rw-r--r-- | include/linux/dm-kcopyd.h | 47 |
3 files changed, 263 insertions, 0 deletions
diff --git a/include/linux/dm-dirty-log.h b/include/linux/dm-dirty-log.h new file mode 100644 index 000000000000..600c5fb2daad --- /dev/null +++ b/include/linux/dm-dirty-log.h @@ -0,0 +1,131 @@ +/* + * Copyright (C) 2003 Sistina Software + * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. + * + * Device-Mapper dirty region log. + * + * This file is released under the LGPL. + */ + +#ifndef _LINUX_DM_DIRTY_LOG +#define _LINUX_DM_DIRTY_LOG + +#ifdef __KERNEL__ + +#include <linux/types.h> +#include <linux/device-mapper.h> + +typedef sector_t region_t; + +struct dm_dirty_log_type; + +struct dm_dirty_log { + struct dm_dirty_log_type *type; + void *context; +}; + +struct dm_dirty_log_type { + const char *name; + struct module *module; + + int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti, + unsigned argc, char **argv); + void (*dtr)(struct dm_dirty_log *log); + + /* + * There are times when we don't want the log to touch + * the disk. + */ + int (*presuspend)(struct dm_dirty_log *log); + int (*postsuspend)(struct dm_dirty_log *log); + int (*resume)(struct dm_dirty_log *log); + + /* + * Retrieves the smallest size of region that the log can + * deal with. + */ + uint32_t (*get_region_size)(struct dm_dirty_log *log); + + /* + * A predicate to say whether a region is clean or not. + * May block. + */ + int (*is_clean)(struct dm_dirty_log *log, region_t region); + + /* + * Returns: 0, 1, -EWOULDBLOCK, < 0 + * + * A predicate function to check the area given by + * [sector, sector + len) is in sync. + * + * If -EWOULDBLOCK is returned the state of the region is + * unknown, typically this will result in a read being + * passed to a daemon to deal with, since a daemon is + * allowed to block. + */ + int (*in_sync)(struct dm_dirty_log *log, region_t region, + int can_block); + + /* + * Flush the current log state (eg, to disk). This + * function may block. + */ + int (*flush)(struct dm_dirty_log *log); + + /* + * Mark an area as clean or dirty. These functions may + * block, though for performance reasons blocking should + * be extremely rare (eg, allocating another chunk of + * memory for some reason). + */ + void (*mark_region)(struct dm_dirty_log *log, region_t region); + void (*clear_region)(struct dm_dirty_log *log, region_t region); + + /* + * Returns: <0 (error), 0 (no region), 1 (region) + * + * The mirrord will need perform recovery on regions of + * the mirror that are in the NOSYNC state. This + * function asks the log to tell the caller about the + * next region that this machine should recover. + * + * Do not confuse this function with 'in_sync()', one + * tells you if an area is synchronised, the other + * assigns recovery work. + */ + int (*get_resync_work)(struct dm_dirty_log *log, region_t *region); + + /* + * This notifies the log that the resync status of a region + * has changed. It also clears the region from the recovering + * list (if present). + */ + void (*set_region_sync)(struct dm_dirty_log *log, + region_t region, int in_sync); + + /* + * Returns the number of regions that are in sync. + */ + region_t (*get_sync_count)(struct dm_dirty_log *log); + + /* + * Support function for mirror status requests. + */ + int (*status)(struct dm_dirty_log *log, status_type_t status_type, + char *result, unsigned maxlen); +}; + +int dm_dirty_log_type_register(struct dm_dirty_log_type *type); +int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type); + +/* + * Make sure you use these two functions, rather than calling + * type->constructor/destructor() directly. + */ +struct dm_dirty_log *dm_dirty_log_create(const char *type_name, + struct dm_target *ti, + unsigned argc, char **argv); +void dm_dirty_log_destroy(struct dm_dirty_log *log); + +#endif /* __KERNEL__ */ +#endif /* _LINUX_DM_DIRTY_LOG_H */ diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h new file mode 100644 index 000000000000..b6bf17ee2f61 --- /dev/null +++ b/include/linux/dm-io.h @@ -0,0 +1,85 @@ +/* + * Copyright (C) 2003 Sistina Software + * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved. + * + * Device-Mapper low-level I/O. + * + * This file is released under the GPL. + */ + +#ifndef _LINUX_DM_IO_H +#define _LINUX_DM_IO_H + +#ifdef __KERNEL__ + +#include <linux/types.h> + +struct dm_io_region { + struct block_device *bdev; + sector_t sector; + sector_t count; /* If this is zero the region is ignored. */ +}; + +struct page_list { + struct page_list *next; + struct page *page; +}; + +typedef void (*io_notify_fn)(unsigned long error, void *context); + +enum dm_io_mem_type { + DM_IO_PAGE_LIST,/* Page list */ + DM_IO_BVEC, /* Bio vector */ + DM_IO_VMA, /* Virtual memory area */ + DM_IO_KMEM, /* Kernel memory */ +}; + +struct dm_io_memory { + enum dm_io_mem_type type; + + union { + struct page_list *pl; + struct bio_vec *bvec; + void *vma; + void *addr; + } ptr; + + unsigned offset; +}; + +struct dm_io_notify { + io_notify_fn fn; /* Callback for asynchronous requests */ + void *context; /* Passed to callback */ +}; + +/* + * IO request structure + */ +struct dm_io_client; +struct dm_io_request { + int bi_rw; /* READ|WRITE - not READA */ + struct dm_io_memory mem; /* Memory to use for io */ + struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */ + struct dm_io_client *client; /* Client memory handler */ +}; + +/* + * For async io calls, users can alternatively use the dm_io() function below + * and dm_io_client_create() to create private mempools for the client. + * + * Create/destroy may block. + */ +struct dm_io_client *dm_io_client_create(unsigned num_pages); +int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client); +void dm_io_client_destroy(struct dm_io_client *client); + +/* + * IO interface using private per-client pools. + * Each bit in the optional 'sync_error_bits' bitset indicates whether an + * error occurred doing io to the corresponding region. + */ +int dm_io(struct dm_io_request *io_req, unsigned num_regions, + struct dm_io_region *region, unsigned long *sync_error_bits); + +#endif /* __KERNEL__ */ +#endif /* _LINUX_DM_IO_H */ diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h new file mode 100644 index 000000000000..5db216311695 --- /dev/null +++ b/include/linux/dm-kcopyd.h @@ -0,0 +1,47 @@ +/* + * 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 <linux/dm-io.h> + +/* FIXME: make this configurable */ +#define DM_KCOPYD_MAX_REGIONS 8 + +#define DM_KCOPYD_IGNORE_ERROR 1 + +/* + * To use kcopyd you must first create a dm_kcopyd_client object. + */ +struct dm_kcopyd_client; +int dm_kcopyd_client_create(unsigned num_pages, + struct dm_kcopyd_client **result); +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); + +#endif /* __KERNEL__ */ +#endif /* _LINUX_DM_KCOPYD_H */ |