40  * Mirror set structures.
50 struct mirror {  struct
81 	atomic_t default_mirror;	/* Default mirror */
91 	struct mirror mirror[];  member
151 	struct mirror *m;
158  * Every mirror should look like this one.
163  * This is yucky.  We squirrel the mirror struct away inside
167 static struct mirror *bio_get_m(struct bio *bio)  in bio_get_m()
169 	return (struct mirror *) bio->bi_next;  in bio_get_m()
172 static void bio_set_m(struct bio *bio, struct mirror *m)  in bio_set_m()
177 static struct mirror *get_default_mirror(struct mirror_set *ms)  in get_default_mirror()
179 	return &ms->mirror[atomic_read(&ms->default_mirror)];  in get_default_mirror()
182 static void set_default_mirror(struct mirror *m)  in set_default_mirror()
185 	struct mirror *m0 = &(ms->mirror[0]);  in set_default_mirror()
190 static struct mirror *get_valid_mirror(struct mirror_set *ms)  in get_valid_mirror()
192 	struct mirror *m;  in get_valid_mirror()
194 	for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++)  in get_valid_mirror()
202  * @m: mirror device to fail
211  * only if the mirror is in-sync.
215 static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)  in fail_mirror()
218 	struct mirror *new;  in fail_mirror()
243 		DMERR("Primary mirror (%s) failed while out-of-sync: Reads may fail.",  in fail_mirror()
252 		DMWARN("All sides of mirror have failed.");  in fail_mirror()
265 	struct mirror *m;  in mirror_flush()
273 	for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) {  in mirror_flush()
284 				fail_mirror(ms->mirror + i,  in mirror_flush()
296  * When a mirror is first activated we may find that some regions
298  * recopying from the default mirror to all the others.
309 		/* Read error means the failure of default mirror. */  in recovery_complete()
310 		DMERR_LIMIT("Unable to read primary mirror during recovery");  in recovery_complete()
318 		 * Bits correspond to devices (excluding default mirror).  in recovery_complete()
319 		 * The default mirror cannot change during recovery.  in recovery_complete()
322 			if (&ms->mirror[m] == get_default_mirror(ms))  in recovery_complete()
325 				fail_mirror(ms->mirror + m,  in recovery_complete()
338 	struct mirror *m;  in recover()
360 		if (&ms->mirror[i] == get_default_mirror(ms))  in recover()
363 		m = ms->mirror + i;  in recover()
384 		atomic_set(&(ms->mirror[m].error_count), 0);  in reset_ms_flags()
385 		ms->mirror[m].error_type = 0;  in reset_ms_flags()
422 static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)  in choose_mirror()
424 	struct mirror *m = get_default_mirror(ms);  in choose_mirror()
430 		if (m-- == ms->mirror)  in choose_mirror()
437 static int default_ok(struct mirror *m)  in default_ok()
439 	struct mirror *default_mirror = get_default_mirror(m->ms);  in default_ok()
456  * remap a buffer to a particular mirror.
458 static sector_t map_sector(struct mirror *m, struct bio *bio)  in map_sector()
465 static void map_bio(struct mirror *m, struct bio *bio)  in map_bio()
471 static void map_region(struct dm_io_region *io, struct mirror *m,  in map_region()
517 	struct mirror *m;  in read_callback()
530 		DMWARN_LIMIT("Read failure on mirror device %s. Trying alternative device.",  in read_callback()
536 	DMERR_LIMIT("Read failure on mirror device %s.  Failing I/O.",  in read_callback()
542 static void read_async_bio(struct mirror *m, struct bio *bio)  in read_async_bio()
570 	struct mirror *m;  in do_reads()
600  * NOSYNC:	increment pending, just write to the default mirror
637 			fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);  in write_callback()
657 	struct mirror *m;  in do_write()
674 	for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)  in do_write()
678 	 * Use default mirror because we only need it to retrieve the reference  in do_write()
679 	 * to the mirror set in write_callback().  in do_write()
808 	 * to reconfigure the mirror, at which point the core  in do_failures()
893 		kzalloc(struct_size(ms, mirror, nr_mirrors), GFP_KERNEL);  in alloc_context()
896 		ti->error = "Cannot allocate mirror context";  in alloc_context()
940 		dm_put_device(ti, ms->mirror[m].dev);  in free_context()
948 		      unsigned int mirror, char **argv)  in get_mirror()  argument
961 			    &ms->mirror[mirror].dev);  in get_mirror()
967 	ms->mirror[mirror].ms = ms;  in get_mirror()
968 	atomic_set(&(ms->mirror[mirror].error_count), 0);  in get_mirror()
969 	ms->mirror[mirror].error_type = 0;  in get_mirror()
970 	ms->mirror[mirror].offset = offset;  in get_mirror()
987 		ti->error = "Insufficient mirror log arguments";  in create_dirty_log()
992 		ti->error = "Invalid mirror log argument count";  in create_dirty_log()
999 		ti->error = "Insufficient mirror log arguments";  in create_dirty_log()
1006 		ti->error = "Error creating mirror dirty log";  in create_dirty_log()
1063  * Construct a mirror mapping:
1099 		ti->error = "Too few mirror arguments";  in mirror_ctr()
1110 	/* Get the mirror parameter sets */  in mirror_ctr()
1159 		ti->error = "Too many mirror arguments";  in mirror_ctr()
1193  * Mirror mapping function
1198 	struct mirror *m;  in mirror_map()
1249 	struct mirror *m = NULL;  in mirror_end_io()
1275 			 * mirror in-sync.  in mirror_end_io()
1277 			DMERR_LIMIT("Mirror read failed.");  in mirror_end_io()
1283 		DMERR("Mirror read failed from %s. Trying alternative device.",  in mirror_end_io()
1290 		 * mirror.  in mirror_end_io()
1381  * @m: mirror device/leg we want the status of
1386  *    D => Dead - A write failure occurred leaving mirror out-of-sync
1387  *    S => Sync - A sychronization failure occurred, mirror out-of-sync
1388  *    R => Read - A read failure occurred, mirror data unaffected
1392 static char device_status_char(struct mirror *m)  in device_status_char()
1417 			DMEMIT("%s ", ms->mirror[m].dev->name);  in mirror_status()
1418 			buffer[m] = device_status_char(&(ms->mirror[m]));  in mirror_status()
1435 			DMEMIT(" %s %llu", ms->mirror[m].dev->name,  in mirror_status()
1436 			       (unsigned long long)ms->mirror[m].offset);  in mirror_status()
1454 			DMEMIT(",mirror_device_%d=%s", m, ms->mirror[m].dev->name);  in mirror_status()
1456 			       m, device_status_char(&(ms->mirror[m])));  in mirror_status()
1477 		ret = fn(ti, ms->mirror[i].dev,  in mirror_iterate_devices()
1478 			 ms->mirror[i].offset, ti->len, data);  in mirror_iterate_devices()
1484 	.name	 = "mirror",
1527 MODULE_DESCRIPTION(DM_NAME " mirror target");