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committed 42bc47b3532static region_t dm_rh_sector_to_region(struct dm_region_hash *rh, sector_t sector)/* * Copyright (C) 2003 Sistina Software Limited. * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. *//*----------------------------------------------------------------- * Region hash * * The mirror splits itself up into discrete regions. Each * region can be in one of three states: clean, dirty, * nosync. There is no need to put clean regions in the hash. * * In addition to being present in the hash table a region _may_ * be present on one of three lists. * * clean_regions: Regions on this list have no io pending to * them, they are in sync, we are no longer interested in them, * they are dull. dm_rh_update_states() will remove them from the * hash table. * * quiesced_regions: These regions have been spun down, ready * for recovery. rh_recovery_start() will remove regions from * this list and hand them to kmirrord, which will schedule the * recovery io with kcopyd. * * recovered_regions: Regions that kcopyd has successfully * recovered. dm_rh_update_states() will now schedule any delayed * io, up the recovery_count, and remove the region from the * hash. * * There are 2 locks: * A rw spin lock 'hash_lock' protects just the hash table, * this is never held in write mode from interrupt context, * which I believe means that we only have to disable irqs when * doing a write lock. * * An ordinary spin lock 'region_lock' that protects the three * lists in the region_hash, with the 'state', 'list' and * 'delayed_bios' fields of the regions. This is used from irq * context, so all other uses will have to suspend local irqs. *---------------------------------------------------------------*/struct dm_region_hash { uint32_t region_size; unsigned region_shift; /* holds persistent region state */ struct dm_dirty_log *log;