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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/device-mapper.h | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/device-mapper.h')
-rw-r--r-- | include/linux/device-mapper.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h new file mode 100644 index 000000000000..83c7d207b80e --- /dev/null +++ b/include/linux/device-mapper.h @@ -0,0 +1,130 @@ +/* + * Copyright (C) 2001 Sistina Software (UK) Limited. + * Copyright (C) 2004 Red Hat, Inc. All rights reserved. + * + * This file is released under the LGPL. + */ + +#ifndef _LINUX_DEVICE_MAPPER_H +#define _LINUX_DEVICE_MAPPER_H + +struct dm_target; +struct dm_table; +struct dm_dev; + +typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; + +union map_info { + void *ptr; + unsigned long long ll; +}; + +/* + * In the constructor the target parameter will already have the + * table, type, begin and len fields filled in. + */ +typedef int (*dm_ctr_fn) (struct dm_target *target, + unsigned int argc, char **argv); + +/* + * The destructor doesn't need to free the dm_target, just + * anything hidden ti->private. + */ +typedef void (*dm_dtr_fn) (struct dm_target *ti); + +/* + * The map function must return: + * < 0: error + * = 0: The target will handle the io by resubmitting it later + * > 0: simple remap complete + */ +typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio, + union map_info *map_context); + +/* + * Returns: + * < 0 : error (currently ignored) + * 0 : ended successfully + * 1 : for some reason the io has still not completed (eg, + * multipath target might want to requeue a failed io). + */ +typedef int (*dm_endio_fn) (struct dm_target *ti, + struct bio *bio, int error, + union map_info *map_context); + +typedef void (*dm_presuspend_fn) (struct dm_target *ti); +typedef void (*dm_postsuspend_fn) (struct dm_target *ti); +typedef void (*dm_resume_fn) (struct dm_target *ti); + +typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type, + char *result, unsigned int maxlen); + +typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv); + +void dm_error(const char *message); + +/* + * Constructors should call these functions to ensure destination devices + * are opened/closed correctly. + * FIXME: too many arguments. + */ +int dm_get_device(struct dm_target *ti, const char *path, sector_t start, + sector_t len, int mode, struct dm_dev **result); +void dm_put_device(struct dm_target *ti, struct dm_dev *d); + +/* + * Information about a target type + */ +struct target_type { + const char *name; + struct module *module; + unsigned version[3]; + dm_ctr_fn ctr; + dm_dtr_fn dtr; + dm_map_fn map; + dm_endio_fn end_io; + dm_presuspend_fn presuspend; + dm_postsuspend_fn postsuspend; + dm_resume_fn resume; + dm_status_fn status; + dm_message_fn message; +}; + +struct io_restrictions { + unsigned short max_sectors; + unsigned short max_phys_segments; + unsigned short max_hw_segments; + unsigned short hardsect_size; + unsigned int max_segment_size; + unsigned long seg_boundary_mask; +}; + +struct dm_target { + struct dm_table *table; + struct target_type *type; + + /* target limits */ + sector_t begin; + sector_t len; + + /* FIXME: turn this into a mask, and merge with io_restrictions */ + /* Always a power of 2 */ + sector_t split_io; + + /* + * These are automatically filled in by + * dm_table_get_device. + */ + struct io_restrictions limits; + + /* target specific data */ + void *private; + + /* Used to provide an error string from the ctr */ + char *error; +}; + +int dm_register_target(struct target_type *t); +int dm_unregister_target(struct target_type *t); + +#endif /* _LINUX_DEVICE_MAPPER_H */ |