10 #include <linux/dm-region-hash.h>
20 #define	DM_MSG_PREFIX	"region hash"
24  * Region hash
27  * region can be in one of three states: clean, dirty,
30  * In addition to being present in the hash table a region _may_
45  *   io, up the recovery_count, and remove the region from the
64 	/* holds persistent region state */
125 sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region)  in dm_rh_region_to_sector()  argument
127 	return region << rh->region_shift;  in dm_rh_region_to_sector()
189 		DMERR("unable to allocate region hash memory");  in dm_region_hash_create()
211 		DMERR("unable to allocate region hash bucket memory");  in dm_region_hash_create()
269 static unsigned int rh_hash(struct dm_region_hash *rh, region_t region)  in rh_hash()  argument
271 	return (unsigned int) ((region * rh->prime) >> rh->shift) & rh->mask;  in rh_hash()
274 static struct dm_region *__rh_lookup(struct dm_region_hash *rh, region_t region)  in __rh_lookup()  argument
277 	struct list_head *bucket = rh->buckets + rh_hash(rh, region);  in __rh_lookup()
280 		if (reg->key == region)  in __rh_lookup()
291 static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region)  in __rh_alloc()  argument
299 	nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?  in __rh_alloc()
302 	nreg->key = region;  in __rh_alloc()
308 	reg = __rh_lookup(rh, region);  in __rh_alloc()
327 static struct dm_region *__rh_find(struct dm_region_hash *rh, region_t region)  in __rh_find()  argument
331 	reg = __rh_lookup(rh, region);  in __rh_find()
334 		reg = __rh_alloc(rh, region);  in __rh_find()
341 int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block)  in dm_rh_get_state()  argument
347 	reg = __rh_lookup(rh, region);  in dm_rh_get_state()
354 	 * The region wasn't in the hash, so we fall back to the  in dm_rh_get_state()
357 	r = rh->log->type->in_sync(rh->log, region, may_block);  in dm_rh_get_state()
393  * We can successfully endio the bio but should avoid the region being
403 	region_t region = dm_rh_bio_to_region(rh, bio);  in dm_rh_mark_nosync()  local
415 	log->type->set_region_sync(log, region, 0);  in dm_rh_mark_nosync()
418 	reg = __rh_find(rh, region);  in dm_rh_mark_nosync()
421 	/* region hash entry should exist because write was in-flight */  in dm_rh_mark_nosync()
431 	 * Either case, the region should have not been connected to list.  in dm_rh_mark_nosync()
506 static void rh_inc(struct dm_region_hash *rh, region_t region)  in rh_inc()  argument
511 	reg = __rh_find(rh, region);  in rh_inc()
541 void dm_rh_dec(struct dm_region_hash *rh, region_t region)  in dm_rh_dec()  argument
548 	reg = __rh_lookup(rh, region);  in dm_rh_dec()
554 		 * There is no pending I/O for this region.  in dm_rh_dec()
555 		 * We can move the region to corresponding list for next action.  in dm_rh_dec()
556 		 * At this point, the region is not yet connected to any list.  in dm_rh_dec()
558 		 * If the state is DM_RH_NOSYNC, the region should be kept off  in dm_rh_dec()
561 		 * until the region is recovered or the map is reloaded.  in dm_rh_dec()
588  * Starts quiescing a region in preparation for recovery.
593 	region_t region;  in __rh_recovery_prepare()  local
599 	r = rh->log->type->get_resync_work(rh->log, &region);  in __rh_recovery_prepare()
604 	 * Get this region, and start it quiescing by setting the  in __rh_recovery_prepare()
608 	reg = __rh_find(rh, region);  in __rh_recovery_prepare()
725 MODULE_DESCRIPTION(DM_NAME " region hash");