40  * Mirror set structures.
50 struct mirror {  struct
81 	atomic_t default_mirror;	/* Default mirror */
91 	struct mirror mirror[];  member
152 	struct mirror *m;
159  * Every mirror should look like this one.
164  * This is yucky.  We squirrel the mirror struct away inside
168 static struct mirror *bio_get_m(struct bio *bio)  in bio_get_m()
170 	return (struct mirror *) bio->bi_next;  in bio_get_m()
173 static void bio_set_m(struct bio *bio, struct mirror *m)  in bio_set_m()
178 static struct mirror *get_default_mirror(struct mirror_set *ms)  in get_default_mirror()
180 	return &ms->mirror[atomic_read(&ms->default_mirror)];  in get_default_mirror()
183 static void set_default_mirror(struct mirror *m)  in set_default_mirror()
186 	struct mirror *m0 = &(ms->mirror[0]);  in set_default_mirror()
191 static struct mirror *get_valid_mirror(struct mirror_set *ms)  in get_valid_mirror()
193 	struct mirror *m;  in get_valid_mirror()
195 	for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++)  in get_valid_mirror()
203  * @m: mirror device to fail
212  * only if the mirror is in-sync.
216 static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)  in fail_mirror()
219 	struct mirror *new;  in fail_mirror()
244 		DMERR("Primary mirror (%s) failed while out-of-sync: Reads may fail.",  in fail_mirror()
253 		DMWARN("All sides of mirror have failed.");  in fail_mirror()
266 	struct mirror *m;  in mirror_flush()
274 	for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) {  in mirror_flush()
285 				fail_mirror(ms->mirror + i,  in mirror_flush()
297  * When a mirror is first activated we may find that some regions
299  * recopying from the default mirror to all the others.
310 		/* Read error means the failure of default mirror. */  in recovery_complete()
311 		DMERR_LIMIT("Unable to read primary mirror during recovery");  in recovery_complete()
319 		 * Bits correspond to devices (excluding default mirror).  in recovery_complete()
320 		 * The default mirror cannot change during recovery.  in recovery_complete()
323 			if (&ms->mirror[m] == get_default_mirror(ms))  in recovery_complete()
326 				fail_mirror(ms->mirror + m,  in recovery_complete()
339 	struct mirror *m;  in recover()
361 		if (&ms->mirror[i] == get_default_mirror(ms))  in recover()
364 		m = ms->mirror + i;  in recover()
385 		atomic_set(&(ms->mirror[m].error_count), 0);  in reset_ms_flags()
386 		ms->mirror[m].error_type = 0;  in reset_ms_flags()
423 static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)  in choose_mirror()
425 	struct mirror *m = get_default_mirror(ms);  in choose_mirror()
431 		if (m-- == ms->mirror)  in choose_mirror()
438 static int default_ok(struct mirror *m)  in default_ok()
440 	struct mirror *default_mirror = get_default_mirror(m->ms);  in default_ok()
457  * remap a buffer to a particular mirror.
459 static sector_t map_sector(struct mirror *m, struct bio *bio)  in map_sector()
466 static void map_bio(struct mirror *m, struct bio *bio)  in map_bio()
472 static void map_region(struct dm_io_region *io, struct mirror *m,  in map_region()
518 	struct mirror *m;  in read_callback()
531 		DMWARN_LIMIT("Read failure on mirror device %s. Trying alternative device.",  in read_callback()
537 	DMERR_LIMIT("Read failure on mirror device %s.  Failing I/O.",  in read_callback()
543 static void read_async_bio(struct mirror *m, struct bio *bio)  in read_async_bio()
571 	struct mirror *m;  in do_reads()
601  * NOSYNC:	increment pending, just write to the default mirror
638 			fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);  in write_callback()
658 	struct mirror *m;  in do_write()
675 	for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)  in do_write()
679 	 * Use default mirror because we only need it to retrieve the reference  in do_write()
680 	 * to the mirror set in write_callback().  in do_write()
809 	 * to reconfigure the mirror, at which point the core  in do_failures()
894 		kzalloc(struct_size(ms, mirror, nr_mirrors), GFP_KERNEL);  in alloc_context()
897 		ti->error = "Cannot allocate mirror context";  in alloc_context()
941 		dm_put_device(ti, ms->mirror[m].dev);  in free_context()
949 		      unsigned int mirror, char **argv)  in get_mirror()  argument
962 			    &ms->mirror[mirror].dev);  in get_mirror()
968 	ms->mirror[mirror].ms = ms;  in get_mirror()
969 	atomic_set(&(ms->mirror[mirror].error_count), 0);  in get_mirror()
970 	ms->mirror[mirror].error_type = 0;  in get_mirror()
971 	ms->mirror[mirror].offset = offset;  in get_mirror()
988 		ti->error = "Insufficient mirror log arguments";  in create_dirty_log()
993 		ti->error = "Invalid mirror log argument count";  in create_dirty_log()
1000 		ti->error = "Insufficient mirror log arguments";  in create_dirty_log()
1007 		ti->error = "Error creating mirror dirty log";  in create_dirty_log()
1064  * Construct a mirror mapping:
1100 		ti->error = "Too few mirror arguments";  in mirror_ctr()
1111 	/* Get the mirror parameter sets */  in mirror_ctr()
1160 		ti->error = "Too many mirror arguments";  in mirror_ctr()
1194  * Mirror mapping function
1199 	struct mirror *m;  in mirror_map()
1250 	struct mirror *m = NULL;  in mirror_end_io()
1276 			 * mirror in-sync.  in mirror_end_io()
1278 			DMERR_LIMIT("Mirror read failed.");  in mirror_end_io()
1284 		DMERR("Mirror read failed from %s. Trying alternative device.",  in mirror_end_io()
1291 		 * mirror.  in mirror_end_io()
1382  * @m: mirror device/leg we want the status of
1387  *    D => Dead - A write failure occurred leaving mirror out-of-sync
1388  *    S => Sync - A sychronization failure occurred, mirror out-of-sync
1389  *    R => Read - A read failure occurred, mirror data unaffected
1393 static char device_status_char(struct mirror *m)  in device_status_char()
1418 			DMEMIT("%s ", ms->mirror[m].dev->name);  in mirror_status()
1419 			buffer[m] = device_status_char(&(ms->mirror[m]));  in mirror_status()
1436 			DMEMIT(" %s %llu", ms->mirror[m].dev->name,  in mirror_status()
1437 			       (unsigned long long)ms->mirror[m].offset);  in mirror_status()
1455 			DMEMIT(",mirror_device_%d=%s", m, ms->mirror[m].dev->name);  in mirror_status()
1457 			       m, device_status_char(&(ms->mirror[m])));  in mirror_status()
1478 		ret = fn(ti, ms->mirror[i].dev,  in mirror_iterate_devices()
1479 			 ms->mirror[i].offset, ti->len, data);  in mirror_iterate_devices()
1485 	.name	 = "mirror",
1528 MODULE_DESCRIPTION(DM_NAME " mirror target");