Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 23 Oct 2008 16:50:12 +0000 (09:50 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 23 Oct 2008 16:50:12 +0000 (09:50 -0700)
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm: tidy local_init
  dm: remove unused flush_all
  dm raid1: separate region_hash interface part1
  dm: mark split bio as cloned
  dm crypt: remove waitqueue
  dm crypt: fix async split
  dm crypt: tidy sector
  dm: remove dm header from targets
  dm: publish array_too_big
  dm exception store: fix misordered writes
  dm exception store: refactor zero_area
  dm snapshot: drop unused last_percent
  dm snapshot: fix primary_pe race
  dm kcopyd: avoid queue shuffle

21 files changed:
drivers/md/Makefile
drivers/md/dm-crypt.c
drivers/md/dm-delay.c
drivers/md/dm-exception-store.c
drivers/md/dm-io.c
drivers/md/dm-kcopyd.c
drivers/md/dm-linear.c
drivers/md/dm-log.c
drivers/md/dm-mpath.c
drivers/md/dm-path-selector.c
drivers/md/dm-raid1.c
drivers/md/dm-region-hash.c [new file with mode: 0644]
drivers/md/dm-round-robin.c
drivers/md/dm-snap.c
drivers/md/dm-snap.h
drivers/md/dm-stripe.c
drivers/md/dm-zero.c
drivers/md/dm.c
drivers/md/dm.h
include/linux/device-mapper.h
include/linux/dm-region-hash.h [new file with mode: 0644]

index f1ef33dfd8cf42bafc5debb9b53464107245f202..1c615804ea76180f5bf2b32c07d7e62bc96d8c67 100644 (file)
@@ -34,7 +34,7 @@ obj-$(CONFIG_DM_CRYPT)                += dm-crypt.o
 obj-$(CONFIG_DM_DELAY)         += dm-delay.o
 obj-$(CONFIG_DM_MULTIPATH)     += dm-multipath.o dm-round-robin.o
 obj-$(CONFIG_DM_SNAPSHOT)      += dm-snapshot.o
-obj-$(CONFIG_DM_MIRROR)                += dm-mirror.o dm-log.o
+obj-$(CONFIG_DM_MIRROR)                += dm-mirror.o dm-log.o dm-region-hash.o
 obj-$(CONFIG_DM_ZERO)          += dm-zero.o
 
 quiet_cmd_unroll = UNROLL  $@
index 682ef9e6acd3344d5bf8a19f4550de90331f37d3..ce26c84af064339f196a0a2eb62b0c55866408b2 100644 (file)
@@ -23,7 +23,7 @@
 #include <asm/page.h>
 #include <asm/unaligned.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "crypt"
 #define MESG_STR(x) x, sizeof(x)
@@ -56,6 +56,7 @@ struct dm_crypt_io {
        atomic_t pending;
        int error;
        sector_t sector;
+       struct dm_crypt_io *base_io;
 };
 
 struct dm_crypt_request {
@@ -93,7 +94,6 @@ struct crypt_config {
 
        struct workqueue_struct *io_queue;
        struct workqueue_struct *crypt_queue;
-       wait_queue_head_t writeq;
 
        /*
         * crypto related data
@@ -534,6 +534,7 @@ static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
        io->base_bio = bio;
        io->sector = sector;
        io->error = 0;
+       io->base_io = NULL;
        atomic_set(&io->pending, 0);
 
        return io;
@@ -547,6 +548,7 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
+ * If base_io is set, wait for the last fragment to complete.
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
@@ -555,7 +557,14 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
        if (!atomic_dec_and_test(&io->pending))
                return;
 
-       bio_endio(io->base_bio, io->error);
+       if (likely(!io->base_io))
+               bio_endio(io->base_bio, io->error);
+       else {
+               if (io->error && !io->base_io->error)
+                       io->base_io->error = io->error;
+               crypt_dec_pending(io->base_io);
+       }
+
        mempool_free(io, cc->io_pool);
 }
 
@@ -646,10 +655,7 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
 static void kcryptd_io_write(struct dm_crypt_io *io)
 {
        struct bio *clone = io->ctx.bio_out;
-       struct crypt_config *cc = io->target->private;
-
        generic_make_request(clone);
-       wake_up(&cc->writeq);
 }
 
 static void kcryptd_io(struct work_struct *work)
@@ -688,7 +694,6 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
        BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
 
        clone->bi_sector = cc->start + io->sector;
-       io->sector += bio_sectors(clone);
 
        if (async)
                kcryptd_queue_io(io);
@@ -700,16 +705,18 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
        struct crypt_config *cc = io->target->private;
        struct bio *clone;
+       struct dm_crypt_io *new_io;
        int crypt_finished;
        unsigned out_of_pages = 0;
        unsigned remaining = io->base_bio->bi_size;
+       sector_t sector = io->sector;
        int r;
 
        /*
         * Prevent io from disappearing until this function completes.
         */
        crypt_inc_pending(io);
-       crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
+       crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
 
        /*
         * The allocated buffers can be smaller than the whole bio,
@@ -726,6 +733,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                io->ctx.idx_out = 0;
 
                remaining -= clone->bi_size;
+               sector += bio_sectors(clone);
 
                crypt_inc_pending(io);
                r = crypt_convert(cc, &io->ctx);
@@ -741,6 +749,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                         */
                        if (unlikely(r < 0))
                                break;
+
+                       io->sector = sector;
                }
 
                /*
@@ -750,8 +760,33 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                if (unlikely(out_of_pages))
                        congestion_wait(WRITE, HZ/100);
 
-               if (unlikely(remaining))
-                       wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
+               /*
+                * With async crypto it is unsafe to share the crypto context
+                * between fragments, so switch to a new dm_crypt_io structure.
+                */
+               if (unlikely(!crypt_finished && remaining)) {
+                       new_io = crypt_io_alloc(io->target, io->base_bio,
+                                               sector);
+                       crypt_inc_pending(new_io);
+                       crypt_convert_init(cc, &new_io->ctx, NULL,
+                                          io->base_bio, sector);
+                       new_io->ctx.idx_in = io->ctx.idx_in;
+                       new_io->ctx.offset_in = io->ctx.offset_in;
+
+                       /*
+                        * Fragments after the first use the base_io
+                        * pending count.
+                        */
+                       if (!io->base_io)
+                               new_io->base_io = io;
+                       else {
+                               new_io->base_io = io->base_io;
+                               crypt_inc_pending(io->base_io);
+                               crypt_dec_pending(io);
+                       }
+
+                       io = new_io;
+               }
        }
 
        crypt_dec_pending(io);
@@ -1078,7 +1113,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                goto bad_crypt_queue;
        }
 
-       init_waitqueue_head(&cc->writeq);
        ti->private = cc;
        return 0;
 
index bdd37f881c42ab757cb381514db10d4d232b854e..848b381f11732c626161ecc8f8c06e5d82927a07 100644 (file)
@@ -13,7 +13,8 @@
 #include <linux/bio.h>
 #include <linux/slab.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-bio-list.h"
 
 #define DM_MSG_PREFIX "delay"
index 769ab677f8e05a4b3887093be5e98e0cf9cd4125..01590f3e00093ffd25e9fe0aa6e70d1472e607f4 100644 (file)
@@ -7,7 +7,6 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
 #include "dm-snap.h"
 
 #include <linux/mm.h>
@@ -104,6 +103,11 @@ struct pstore {
         */
        void *area;
 
+       /*
+        * An area of zeros used to clear the next area.
+        */
+       void *zero_area;
+
        /*
         * Used to keep track of which metadata area the data in
         * 'chunk' refers to.
@@ -149,6 +153,13 @@ static int alloc_area(struct pstore *ps)
        if (!ps->area)
                return r;
 
+       ps->zero_area = vmalloc(len);
+       if (!ps->zero_area) {
+               vfree(ps->area);
+               return r;
+       }
+       memset(ps->zero_area, 0, len);
+
        return 0;
 }
 
@@ -156,6 +167,8 @@ static void free_area(struct pstore *ps)
 {
        vfree(ps->area);
        ps->area = NULL;
+       vfree(ps->zero_area);
+       ps->zero_area = NULL;
 }
 
 struct mdata_req {
@@ -220,25 +233,41 @@ static chunk_t area_location(struct pstore *ps, chunk_t area)
  * Read or write a metadata area.  Remembering to skip the first
  * chunk which holds the header.
  */
-static int area_io(struct pstore *ps, chunk_t area, int rw)
+static int area_io(struct pstore *ps, int rw)
 {
        int r;
        chunk_t chunk;
 
-       chunk = area_location(ps, area);
+       chunk = area_location(ps, ps->current_area);
 
        r = chunk_io(ps, chunk, rw, 0);
        if (r)
                return r;
 
-       ps->current_area = area;
        return 0;
 }
 
-static int zero_area(struct pstore *ps, chunk_t area)
+static void zero_memory_area(struct pstore *ps)
 {
        memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
-       return area_io(ps, area, WRITE);
+}
+
+static int zero_disk_area(struct pstore *ps, chunk_t area)
+{
+       struct dm_io_region where = {
+               .bdev = ps->snap->cow->bdev,
+               .sector = ps->snap->chunk_size * area_location(ps, area),
+               .count = ps->snap->chunk_size,
+       };
+       struct dm_io_request io_req = {
+               .bi_rw = WRITE,
+               .mem.type = DM_IO_VMA,
+               .mem.ptr.vma = ps->zero_area,
+               .client = ps->io_client,
+               .notify.fn = NULL,
+       };
+
+       return dm_io(&io_req, 1, &where, NULL);
 }
 
 static int read_header(struct pstore *ps, int *new_snapshot)
@@ -411,15 +440,14 @@ static int insert_exceptions(struct pstore *ps, int *full)
 
 static int read_exceptions(struct pstore *ps)
 {
-       chunk_t area;
        int r, full = 1;
 
        /*
         * Keeping reading chunks and inserting exceptions until
         * we find a partially full area.
         */
-       for (area = 0; full; area++) {
-               r = area_io(ps, area, READ);
+       for (ps->current_area = 0; full; ps->current_area++) {
+               r = area_io(ps, READ);
                if (r)
                        return r;
 
@@ -428,6 +456,8 @@ static int read_exceptions(struct pstore *ps)
                        return r;
        }
 
+       ps->current_area--;
+
        return 0;
 }
 
@@ -486,12 +516,13 @@ static int persistent_read_metadata(struct exception_store *store)
                        return r;
                }
 
-               r = zero_area(ps, 0);
+               ps->current_area = 0;
+               zero_memory_area(ps);
+               r = zero_disk_area(ps, 0);
                if (r) {
-                       DMWARN("zero_area(0) failed");
+                       DMWARN("zero_disk_area(0) failed");
                        return r;
                }
-
        } else {
                /*
                 * Sanity checks.
@@ -551,7 +582,6 @@ static void persistent_commit(struct exception_store *store,
                              void (*callback) (void *, int success),
                              void *callback_context)
 {
-       int r;
        unsigned int i;
        struct pstore *ps = get_info(store);
        struct disk_exception de;
@@ -572,33 +602,41 @@ static void persistent_commit(struct exception_store *store,
        cb->context = callback_context;
 
        /*
-        * If there are no more exceptions in flight, or we have
-        * filled this metadata area we commit the exceptions to
-        * disk.
+        * If there are exceptions in flight and we have not yet
+        * filled this metadata area there's nothing more to do.
         */
-       if (atomic_dec_and_test(&ps->pending_count) ||
-           (ps->current_committed == ps->exceptions_per_area)) {
-               r = area_io(ps, ps->current_area, WRITE);
-               if (r)
-                       ps->valid = 0;
+       if (!atomic_dec_and_test(&ps->pending_count) &&
+           (ps->current_committed != ps->exceptions_per_area))
+               return;
 
-               /*
-                * Have we completely filled the current area ?
-                */
-               if (ps->current_committed == ps->exceptions_per_area) {
-                       ps->current_committed = 0;
-                       r = zero_area(ps, ps->current_area + 1);
-                       if (r)
-                               ps->valid = 0;
-               }
+       /*
+        * If we completely filled the current area, then wipe the next one.
+        */
+       if ((ps->current_committed == ps->exceptions_per_area) &&
+            zero_disk_area(ps, ps->current_area + 1))
+               ps->valid = 0;
 
-               for (i = 0; i < ps->callback_count; i++) {
-                       cb = ps->callbacks + i;
-                       cb->callback(cb->context, r == 0 ? 1 : 0);
-               }
+       /*
+        * Commit exceptions to disk.
+        */
+       if (ps->valid && area_io(ps, WRITE))
+               ps->valid = 0;
 
-               ps->callback_count = 0;
+       /*
+        * Advance to the next area if this one is full.
+        */
+       if (ps->current_committed == ps->exceptions_per_area) {
+               ps->current_committed = 0;
+               ps->current_area++;
+               zero_memory_area(ps);
        }
+
+       for (i = 0; i < ps->callback_count; i++) {
+               cb = ps->callbacks + i;
+               cb->callback(cb->context, ps->valid);
+       }
+
+       ps->callback_count = 0;
 }
 
 static void persistent_drop(struct exception_store *store)
index 4789c42d9a3ac503d53ba6ea77fe7fadbee21682..2fd6d4450637943963d88c948080cf4f0ed73a92 100644 (file)
@@ -5,7 +5,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/bio.h>
 #include <linux/mempool.h>
index 996802b8a4522e50126365d070f21458f9b68be2..3073618269ea3030e468541ea2af6f05dd2aac65 100644 (file)
@@ -22,6 +22,7 @@
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>
+#include <linux/device-mapper.h>
 #include <linux/dm-kcopyd.h>
 
 #include "dm.h"
@@ -268,6 +269,17 @@ static void push(struct list_head *jobs, struct kcopyd_job *job)
        spin_unlock_irqrestore(&kc->job_lock, flags);
 }
 
+
+static void push_head(struct list_head *jobs, struct kcopyd_job *job)
+{
+       unsigned long flags;
+       struct dm_kcopyd_client *kc = job->kc;
+
+       spin_lock_irqsave(&kc->job_lock, flags);
+       list_add(&job->list, jobs);
+       spin_unlock_irqrestore(&kc->job_lock, flags);
+}
+
 /*
  * These three functions process 1 item from the corresponding
  * job list.
@@ -398,7 +410,7 @@ static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc,
                         * We couldn't service this job ATM, so
                         * push this job back onto the list.
                         */
-                       push(jobs, job);
+                       push_head(jobs, job);
                        break;
                }
 
index 6449bcdf84ca47465673223fa3a27f88c44684ce..1b29e9136758523edcc8925018fda84056d8be4b 100644 (file)
@@ -5,12 +5,12 @@
  */
 
 #include "dm.h"
-
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
 #include <linux/slab.h>
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "linear"
 
index 5b48478c79f53037474579edf1930b4d103b160c..a8c0fc79ca78c18d52631bb3e27176ee68c4712f 100644 (file)
@@ -12,7 +12,7 @@
 #include <linux/dm-io.h>
 #include <linux/dm-dirty-log.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "dirty region log"
 
index 9bf3460c5540b9fdbefbacaed15788f7a6868fb0..abf6e8cfaedbaba1a5535da6c8157748200bf0f9 100644 (file)
@@ -5,7 +5,8 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 #include "dm-bio-list.h"
 #include "dm-bio-record.h"
index ca1bb636a3e4ba808ae63d88dfbb62bc4ee28a04..96ea226155b10e3dbb560b3faa8c2211ec11f41f 100644 (file)
@@ -9,7 +9,8 @@
  * Path selector registration.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 
 #include <linux/slab.h>
index 29913e42c4ab436da84fc7fdf6e42da4fe051e49..92dcc06832a462a3210fbd521c323abce9b43cd0 100644 (file)
 /*
  * Copyright (C) 2003 Sistina Software Limited.
+ * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
  *
  * This file is released under the GPL.
  */
 
-#include "dm.h"
 #include "dm-bio-list.h"
 #include "dm-bio-record.h"
 
-#include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/mempool.h>
 #include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/slab.h>
-#include <linux/time.h>
-#include <linux/vmalloc.h>
 #include <linux/workqueue.h>
-#include <linux/log2.h>
-#include <linux/hardirq.h>
+#include <linux/device-mapper.h>
 #include <linux/dm-io.h>
 #include <linux/dm-dirty-log.h>
 #include <linux/dm-kcopyd.h>
+#include <linux/dm-region-hash.h>
 
 #define DM_MSG_PREFIX "raid1"
+
+#define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */
 #define DM_IO_PAGES 64
+#define DM_KCOPYD_PAGES 64
 
 #define DM_RAID1_HANDLE_ERRORS 0x01
 #define errors_handled(p)      ((p)->features & DM_RAID1_HANDLE_ERRORS)
 
 static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
 
-/*-----------------------------------------------------------------
- * 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.  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.  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
- *   'bhs_delayed' fields of the regions.  This is used from irq
- *   context, so all other uses will have to suspend local irqs.
- *---------------------------------------------------------------*/
-struct mirror_set;
-struct region_hash {
-       struct mirror_set *ms;
-       uint32_t region_size;
-       unsigned region_shift;
-
-       /* holds persistent region state */
-       struct dm_dirty_log *log;
-
-       /* hash table */
-       rwlock_t hash_lock;
-       mempool_t *region_pool;
-       unsigned int mask;
-       unsigned int nr_buckets;
-       struct list_head *buckets;
-
-       spinlock_t region_lock;
-       atomic_t recovery_in_flight;
-       struct semaphore recovery_count;
-       struct list_head clean_regions;
-       struct list_head quiesced_regions;
-       struct list_head recovered_regions;
-       struct list_head failed_recovered_regions;
-};
-
-enum {
-       RH_CLEAN,
-       RH_DIRTY,
-       RH_NOSYNC,
-       RH_RECOVERING
-};
-
-struct region {
-       struct region_hash *rh; /* FIXME: can we get rid of this ? */
-       region_t key;
-       int state;
-
-       struct list_head hash_list;
-       struct list_head list;
-
-       atomic_t pending;
-       struct bio_list delayed_bios;
-};
-
-
 /*-----------------------------------------------------------------
  * Mirror set structures.
  *---------------------------------------------------------------*/
@@ -132,8 +51,7 @@ struct mirror {
 struct mirror_set {
        struct dm_target *ti;
        struct list_head list;
-       struct region_hash rh;
-       struct dm_kcopyd_client *kcopyd_client;
+
        uint64_t features;
 
        spinlock_t lock;        /* protects the lists */
@@ -141,6 +59,8 @@ struct mirror_set {
        struct bio_list writes;
        struct bio_list failures;
 
+       struct dm_region_hash *rh;
+       struct dm_kcopyd_client *kcopyd_client;
        struct dm_io_client *io_client;
        mempool_t *read_record_pool;
 
@@ -159,25 +79,14 @@ struct mirror_set {
 
        struct work_struct trigger_event;
 
-       unsigned int nr_mirrors;
+       unsigned nr_mirrors;
        struct mirror mirror[0];
 };
 
-/*
- * Conversion fns
- */
-static inline region_t bio_to_region(struct region_hash *rh, struct bio *bio)
-{
-       return (bio->bi_sector - rh->ms->ti->begin) >> rh->region_shift;
-}
-
-static inline sector_t region_to_sector(struct region_hash *rh, region_t region)
+static void wakeup_mirrord(void *context)
 {
-       return region << rh->region_shift;
-}
+       struct mirror_set *ms = context;
 
-static void wake(struct mirror_set *ms)
-{
        queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
 }
 
@@ -186,7 +95,7 @@ static void delayed_wake_fn(unsigned long data)
        struct mirror_set *ms = (struct mirror_set *) data;
 
        clear_bit(0, &ms->timer_pending);
-       wake(ms);
+       wakeup_mirrord(ms);
 }
 
 static void delayed_wake(struct mirror_set *ms)
@@ -200,473 +109,34 @@ static void delayed_wake(struct mirror_set *ms)
        add_timer(&ms->timer);
 }
 
-/* FIXME move this */
-static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw);
-
-#define MIN_REGIONS 64
-#define MAX_RECOVERY 1
-static int rh_init(struct region_hash *rh, struct mirror_set *ms,
-                  struct dm_dirty_log *log, uint32_t region_size,
-                  region_t nr_regions)
+static void wakeup_all_recovery_waiters(void *context)
 {
-       unsigned int nr_buckets, max_buckets;
-       size_t i;
-
-       /*
-        * Calculate a suitable number of buckets for our hash
-        * table.
-        */
-       max_buckets = nr_regions >> 6;
-       for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1)
-               ;
-       nr_buckets >>= 1;
-
-       rh->ms = ms;
-       rh->log = log;
-       rh->region_size = region_size;
-       rh->region_shift = ffs(region_size) - 1;
-       rwlock_init(&rh->hash_lock);
-       rh->mask = nr_buckets - 1;
-       rh->nr_buckets = nr_buckets;
-
-       rh->buckets = vmalloc(nr_buckets * sizeof(*rh->buckets));
-       if (!rh->buckets) {
-               DMERR("unable to allocate region hash memory");
-               return -ENOMEM;
-       }
-
-       for (i = 0; i < nr_buckets; i++)
-               INIT_LIST_HEAD(rh->buckets + i);
-
-       spin_lock_init(&rh->region_lock);
-       sema_init(&rh->recovery_count, 0);
-       atomic_set(&rh->recovery_in_flight, 0);
-       INIT_LIST_HEAD(&rh->clean_regions);
-       INIT_LIST_HEAD(&rh->quiesced_regions);
-       INIT_LIST_HEAD(&rh->recovered_regions);
-       INIT_LIST_HEAD(&rh->failed_recovered_regions);
-
-       rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
-                                                     sizeof(struct region));
-       if (!rh->region_pool) {
-               vfree(rh->buckets);
-               rh->buckets = NULL;
-               return -ENOMEM;
-       }
-
-       return 0;
+       wake_up_all(&_kmirrord_recovery_stopped);
 }
 
-static void rh_exit(struct region_hash *rh)
-{
-       unsigned int h;
-       struct region *reg, *nreg;
-
-       BUG_ON(!list_empty(&rh->quiesced_regions));
-       for (h = 0; h < rh->nr_buckets; h++) {
-               list_for_each_entry_safe(reg, nreg, rh->buckets + h, hash_list) {
-                       BUG_ON(atomic_read(&reg->pending));
-                       mempool_free(reg, rh->region_pool);
-               }
-       }
-
-       if (rh->log)
-               dm_dirty_log_destroy(rh->log);
-       if (rh->region_pool)
-               mempool_destroy(rh->region_pool);
-       vfree(rh->buckets);
-}
-
-#define RH_HASH_MULT 2654435387U
-
-static inline unsigned int rh_hash(struct region_hash *rh, region_t region)
-{
-       return (unsigned int) ((region * RH_HASH_MULT) >> 12) & rh->mask;
-}
-
-static struct region *__rh_lookup(struct region_hash *rh, region_t region)
-{
-       struct region *reg;
-
-       list_for_each_entry (reg, rh->buckets + rh_hash(rh, region), hash_list)
-               if (reg->key == region)
-                       return reg;
-
-       return NULL;
-}
-
-static void __rh_insert(struct region_hash *rh, struct region *reg)
-{
-       unsigned int h = rh_hash(rh, reg->key);
-       list_add(&reg->hash_list, rh->buckets + h);
-}
-
-static struct region *__rh_alloc(struct region_hash *rh, region_t region)
-{
-       struct region *reg, *nreg;
-
-       read_unlock(&rh->hash_lock);
-       nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);
-       if (unlikely(!nreg))
-               nreg = kmalloc(sizeof(struct region), GFP_NOIO);
-       nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
-               RH_CLEAN : RH_NOSYNC;
-       nreg->rh = rh;
-       nreg->key = region;
-
-       INIT_LIST_HEAD(&nreg->list);
-
-       atomic_set(&nreg->pending, 0);
-       bio_list_init(&nreg->delayed_bios);
-       write_lock_irq(&rh->hash_lock);
-
-       reg = __rh_lookup(rh, region);
-       if (reg)
-               /* we lost the race */
-               mempool_free(nreg, rh->region_pool);
-
-       else {
-               __rh_insert(rh, nreg);
-               if (nreg->state == RH_CLEAN) {
-                       spin_lock(&rh->region_lock);
-                       list_add(&nreg->list, &rh->clean_regions);
-                       spin_unlock(&rh->region_lock);
-               }
-               reg = nreg;
-       }
-       write_unlock_irq(&rh->hash_lock);
-       read_lock(&rh->hash_lock);
-
-       return reg;
-}
-
-static inline struct region *__rh_find(struct region_hash *rh, region_t region)
-{
-       struct region *reg;
-
-       reg = __rh_lookup(rh, region);
-       if (!reg)
-               reg = __rh_alloc(rh, region);
-
-       return reg;
-}
-
-static int rh_state(struct region_hash *rh, region_t region, int may_block)
-{
-       int r;
-       struct region *reg;
-
-       read_lock(&rh->hash_lock);
-       reg = __rh_lookup(rh, region);
-       read_unlock(&rh->hash_lock);
-
-       if (reg)
-               return reg->state;
-
-       /*
-        * The region wasn't in the hash, so we fall back to the
-        * dirty log.
-        */
-       r = rh->log->type->in_sync(rh->log, region, may_block);
-
-       /*
-        * Any error from the dirty log (eg. -EWOULDBLOCK) gets
-        * taken as a RH_NOSYNC
-        */
-       return r == 1 ? RH_CLEAN : RH_NOSYNC;
-}
-
-static inline int rh_in_sync(struct region_hash *rh,
-                            region_t region, int may_block)
-{
-       int state = rh_state(rh, region, may_block);
-       return state == RH_CLEAN || state == RH_DIRTY;
-}
-
-static void dispatch_bios(struct mirror_set *ms, struct bio_list *bio_list)
-{
-       struct bio *bio;
-
-       while ((bio = bio_list_pop(bio_list))) {
-               queue_bio(ms, bio, WRITE);
-       }
-}
-
-static void complete_resync_work(struct region *reg, int success)
-{
-       struct region_hash *rh = reg->rh;
-
-       rh->log->type->set_region_sync(rh->log, reg->key, success);
-
-       /*
-        * Dispatch the bios before we call 'wake_up_all'.
-        * This is important because if we are suspending,
-        * we want to know that recovery is complete and
-        * the work queue is flushed.  If we wake_up_all
-        * before we dispatch_bios (queue bios and call wake()),
-        * then we risk suspending before the work queue
-        * has been properly flushed.
-        */
-       dispatch_bios(rh->ms, &reg->delayed_bios);
-       if (atomic_dec_and_test(&rh->recovery_in_flight))
-               wake_up_all(&_kmirrord_recovery_stopped);
-       up(&rh->recovery_count);
-}
-
-static void rh_update_states(struct region_hash *rh)
-{
-       struct region *reg, *next;
-
-       LIST_HEAD(clean);
-       LIST_HEAD(recovered);
-       LIST_HEAD(failed_recovered);
-
-       /*
-        * Quickly grab the lists.
-        */
-       write_lock_irq(&rh->hash_lock);
-       spin_lock(&rh->region_lock);
-       if (!list_empty(&rh->clean_regions)) {
-               list_splice_init(&rh->clean_regions, &clean);
-
-               list_for_each_entry(reg, &clean, list)
-                       list_del(&reg->hash_list);
-       }
-
-       if (!list_empty(&rh->recovered_regions)) {
-               list_splice_init(&rh->recovered_regions, &recovered);
-
-               list_for_each_entry (reg, &recovered, list)
-                       list_del(&reg->hash_list);
-       }
-
-       if (!list_empty(&rh->failed_recovered_regions)) {
-               list_splice_init(&rh->failed_recovered_regions,
-                                &failed_recovered);
-
-               list_for_each_entry(reg, &failed_recovered, list)
-                       list_del(&reg->hash_list);
-       }
-
-       spin_unlock(&rh->region_lock);
-       write_unlock_irq(&rh->hash_lock);
-
-       /*
-        * All the regions on the recovered and clean lists have
-        * now been pulled out of the system, so no need to do
-        * any more locking.
-        */
-       list_for_each_entry_safe (reg, next, &recovered, list) {
-               rh->log->type->clear_region(rh->log, reg->key);
-               complete_resync_work(reg, 1);
-               mempool_free(reg, rh->region_pool);
-       }
-
-       list_for_each_entry_safe(reg, next, &failed_recovered, list) {
-               complete_resync_work(reg, errors_handled(rh->ms) ? 0 : 1);
-               mempool_free(reg, rh->region_pool);
-       }
-
-       list_for_each_entry_safe(reg, next, &clean, list) {
-               rh->log->type->clear_region(rh->log, reg->key);
-               mempool_free(reg, rh->region_pool);
-       }
-
-       rh->log->type->flush(rh->log);
-}
-
-static void rh_inc(struct region_hash *rh, region_t region)
-{
-       struct region *reg;
-
-       read_lock(&rh->hash_lock);
-       reg = __rh_find(rh, region);
-
-       spin_lock_irq(&rh->region_lock);
-       atomic_inc(&reg->pending);
-
-       if (reg->state == RH_CLEAN) {
-               reg->state = RH_DIRTY;
-               list_del_init(&reg->list);      /* take off the clean list */
-               spin_unlock_irq(&rh->region_lock);
-
-               rh->log->type->mark_region(rh->log, reg->key);
-       } else
-               spin_unlock_irq(&rh->region_lock);
-
-
-       read_unlock(&rh->hash_lock);
-}
-
-static void rh_inc_pending(struct region_hash *rh, struct bio_list *bios)
-{
-       struct bio *bio;
-
-       for (bio = bios->head; bio; bio = bio->bi_next)
-               rh_inc(rh, bio_to_region(rh, bio));
-}
-
-static void rh_dec(struct region_hash *rh, region_t region)
+static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
 {
        unsigned long flags;
-       struct region *reg;
        int should_wake = 0;
+       struct bio_list *bl;
 
-       read_lock(&rh->hash_lock);
-       reg = __rh_lookup(rh, region);
-       read_unlock(&rh->hash_lock);
-
-       spin_lock_irqsave(&rh->region_lock, flags);
-       if (atomic_dec_and_test(&reg->pending)) {
-               /*
-                * There is no pending I/O for this region.
-                * We can move the region to corresponding list for next action.
-                * At this point, the region is not yet connected to any list.
-                *
-                * If the state is RH_NOSYNC, the region should be kept off
-                * from clean list.
-                * The hash entry for RH_NOSYNC will remain in memory
-                * until the region is recovered or the map is reloaded.
-                */
-
-               /* do nothing for RH_NOSYNC */
-               if (reg->state == RH_RECOVERING) {
-                       list_add_tail(&reg->list, &rh->quiesced_regions);
-               } else if (reg->state == RH_DIRTY) {
-                       reg->state = RH_CLEAN;
-                       list_add(&reg->list, &rh->clean_regions);
-               }
-               should_wake = 1;
-       }
-       spin_unlock_irqrestore(&rh->region_lock, flags);
+       bl = (rw == WRITE) ? &ms->writes : &ms->reads;
+       spin_lock_irqsave(&ms->lock, flags);
+       should_wake = !(bl->head);
+       bio_list_add(bl, bio);
+       spin_unlock_irqrestore(&ms->lock, flags);
 
        if (should_wake)
-               wake(rh->ms);
-}
-
-/*
- * Starts quiescing a region in preparation for recovery.
- */
-static int __rh_recovery_prepare(struct region_hash *rh)
-{
-       int r;
-       struct region *reg;
-       region_t region;
-
-       /*
-        * Ask the dirty log what's next.
-        */
-       r = rh->log->type->get_resync_work(rh->log, &region);
-       if (r <= 0)
-               return r;
-
-       /*
-        * Get this region, and start it quiescing by setting the
-        * recovering flag.
-        */
-       read_lock(&rh->hash_lock);
-       reg = __rh_find(rh, region);
-       read_unlock(&rh->hash_lock);
-
-       spin_lock_irq(&rh->region_lock);
-       reg->state = RH_RECOVERING;
-
-       /* Already quiesced ? */
-       if (atomic_read(&reg->pending))
-               list_del_init(&reg->list);
-       else
-               list_move(&reg->list, &rh->quiesced_regions);
-
-       spin_unlock_irq(&rh->region_lock);
-
-       return 1;
-}
-
-static void rh_recovery_prepare(struct region_hash *rh)
-{
-       /* Extra reference to avoid race with rh_stop_recovery */
-       atomic_inc(&rh->recovery_in_flight);
-
-       while (!down_trylock(&rh->recovery_count)) {
-               atomic_inc(&rh->recovery_in_flight);
-               if (__rh_recovery_prepare(rh) <= 0) {
-                       atomic_dec(&rh->recovery_in_flight);
-                       up(&rh->recovery_count);
-                       break;
-               }
-       }
-
-       /* Drop the extra reference */
-       if (atomic_dec_and_test(&rh->recovery_in_flight))
-               wake_up_all(&_kmirrord_recovery_stopped);
-}
-
-/*
- * Returns any quiesced regions.
- */
-static struct region *rh_recovery_start(struct region_hash *rh)
-{
-       struct region *reg = NULL;
-
-       spin_lock_irq(&rh->region_lock);
-       if (!list_empty(&rh->quiesced_regions)) {
-               reg = list_entry(rh->quiesced_regions.next,
-                                struct region, list);
-               list_del_init(&reg->list);      /* remove from the quiesced list */
-       }
-       spin_unlock_irq(&rh->region_lock);
-
-       return reg;
-}
-
-static void rh_recovery_end(struct region *reg, int success)
-{
-       struct region_hash *rh = reg->rh;
-
-       spin_lock_irq(&rh->region_lock);
-       if (success)
-               list_add(&reg->list, &reg->rh->recovered_regions);
-       else {
-               reg->state = RH_NOSYNC;
-               list_add(&reg->list, &reg->rh->failed_recovered_regions);
-       }
-       spin_unlock_irq(&rh->region_lock);
-
-       wake(rh->ms);
+               wakeup_mirrord(ms);
 }
 
-static int rh_flush(struct region_hash *rh)
+static void dispatch_bios(void *context, struct bio_list *bio_list)
 {
-       return rh->log->type->flush(rh->log);
-}
-
-static void rh_delay(struct region_hash *rh, struct bio *bio)
-{
-       struct region *reg;
-
-       read_lock(&rh->hash_lock);
-       reg = __rh_find(rh, bio_to_region(rh, bio));
-       bio_list_add(&reg->delayed_bios, bio);
-       read_unlock(&rh->hash_lock);
-}
-
-static void rh_stop_recovery(struct region_hash *rh)
-{
-       int i;
-
-       /* wait for any recovering regions */
-       for (i = 0; i < MAX_RECOVERY; i++)
-               down(&rh->recovery_count);
-}
-
-static void rh_start_recovery(struct region_hash *rh)
-{
-       int i;
-
-       for (i = 0; i < MAX_RECOVERY; i++)
-               up(&rh->recovery_count);
+       struct mirror_set *ms = context;
+       struct bio *bio;
 
-       wake(rh->ms);
+       while ((bio = bio_list_pop(bio_list)))
+               queue_bio(ms, bio, WRITE);
 }
 
 #define MIN_READ_RECORDS 20
@@ -776,8 +246,8 @@ out:
 static void recovery_complete(int read_err, unsigned long write_err,
                              void *context)
 {
-       struct region *reg = (struct region *)context;
-       struct mirror_set *ms = reg->rh->ms;
+       struct dm_region *reg = context;
+       struct mirror_set *ms = dm_rh_region_context(reg);
        int m, bit = 0;
 
        if (read_err) {
@@ -803,31 +273,33 @@ static void recovery_complete(int read_err, unsigned long write_err,
                }
        }
 
-       rh_recovery_end(reg, !(read_err || write_err));
+       dm_rh_recovery_end(reg, !(read_err || write_err));
 }
 
-static int recover(struct mirror_set *ms, struct region *reg)
+static int recover(struct mirror_set *ms, struct dm_region *reg)
 {
        int r;
-       unsigned int i;
+       unsigned i;
        struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest;
        struct mirror *m;
        unsigned long flags = 0;
+       region_t key = dm_rh_get_region_key(reg);
+       sector_t region_size = dm_rh_get_region_size(ms->rh);
 
        /* fill in the source */
        m = get_default_mirror(ms);
        from.bdev = m->dev->bdev;
-       from.sector = m->offset + region_to_sector(reg->rh, reg->key);
-       if (reg->key == (ms->nr_regions - 1)) {
+       from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
+       if (key == (ms->nr_regions - 1)) {
                /*
                 * The final region may be smaller than
                 * region_size.
                 */
-               from.count = ms->ti->len & (reg->rh->region_size - 1);
+               from.count = ms->ti->len & (region_size - 1);
                if (!from.count)
-                       from.count = reg->rh->region_size;
+                       from.count = region_size;
        } else
-               from.count = reg->rh->region_size;
+               from.count = region_size;
 
        /* fill in the destinations */
        for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
@@ -836,7 +308,7 @@ static int recover(struct mirror_set *ms, struct region *reg)
 
                m = ms->mirror + i;
                dest->bdev = m->dev->bdev;
-               dest->sector = m->offset + region_to_sector(reg->rh, reg->key);
+               dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
                dest->count = from.count;
                dest++;
        }
@@ -853,22 +325,22 @@ static int recover(struct mirror_set *ms, struct region *reg)
 
 static void do_recovery(struct mirror_set *ms)
 {
+       struct dm_region *reg;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
        int r;
-       struct region *reg;
-       struct dm_dirty_log *log = ms->rh.log;
 
        /*
         * Start quiescing some regions.
         */
-       rh_recovery_prepare(&ms->rh);
+       dm_rh_recovery_prepare(ms->rh);
 
        /*
         * Copy any already quiesced regions.
         */
-       while ((reg = rh_recovery_start(&ms->rh))) {
+       while ((reg = dm_rh_recovery_start(ms->rh))) {
                r = recover(ms, reg);
                if (r)
-                       rh_recovery_end(reg, 0);
+                       dm_rh_recovery_end(reg, 0);
        }
 
        /*
@@ -909,9 +381,10 @@ static int default_ok(struct mirror *m)
 
 static int mirror_available(struct mirror_set *ms, struct bio *bio)
 {
-       region_t region = bio_to_region(&ms->rh, bio);
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+       region_t region = dm_rh_bio_to_region(ms->rh, bio);
 
-       if (ms->rh.log->type->in_sync(ms->rh.log, region, 0))
+       if (log->type->in_sync(log, region, 0))
                return choose_mirror(ms,  bio->bi_sector) ? 1 : 0;
 
        return 0;
@@ -985,7 +458,14 @@ static void read_async_bio(struct mirror *m, struct bio *bio)
 
        map_region(&io, m, bio);
        bio_set_m(bio, m);
-       (void) dm_io(&io_req, 1, &io, NULL);
+       BUG_ON(dm_io(&io_req, 1, &io, NULL));
+}
+
+static inline int region_in_sync(struct mirror_set *ms, region_t region,
+                                int may_block)
+{
+       int state = dm_rh_get_state(ms->rh, region, may_block);
+       return state == DM_RH_CLEAN || state == DM_RH_DIRTY;
 }
 
 static void do_reads(struct mirror_set *ms, struct bio_list *reads)
@@ -995,13 +475,13 @@ static void do_reads(struct mirror_set *ms, struct bio_list *reads)
        struct mirror *m;
 
        while ((bio = bio_list_pop(reads))) {
-               region = bio_to_region(&ms->rh, bio);
+               region = dm_rh_bio_to_region(ms->rh, bio);
                m = get_default_mirror(ms);
 
                /*
                 * We can only read balance if the region is in sync.
                 */
-               if (likely(rh_in_sync(&ms->rh, region, 1)))
+               if (likely(region_in_sync(ms, region, 1)))
                        m = choose_mirror(ms, bio->bi_sector);
                else if (m && atomic_read(&m->error_count))
                        m = NULL;
@@ -1024,57 +504,6 @@ static void do_reads(struct mirror_set *ms, struct bio_list *reads)
  * NOSYNC:     increment pending, just write to the default mirror
  *---------------------------------------------------------------*/
 
-/* __bio_mark_nosync
- * @ms
- * @bio
- * @done
- * @error
- *
- * The bio was written on some mirror(s) but failed on other mirror(s).
- * We can successfully endio the bio but should avoid the region being
- * marked clean by setting the state RH_NOSYNC.
- *
- * This function is _not_ safe in interrupt context!
- */
-static void __bio_mark_nosync(struct mirror_set *ms,
-                             struct bio *bio, unsigned done, int error)
-{
-       unsigned long flags;
-       struct region_hash *rh = &ms->rh;
-       struct dm_dirty_log *log = ms->rh.log;
-       struct region *reg;
-       region_t region = bio_to_region(rh, bio);
-       int recovering = 0;
-
-       /* We must inform the log that the sync count has changed. */
-       log->type->set_region_sync(log, region, 0);
-       ms->in_sync = 0;
-
-       read_lock(&rh->hash_lock);
-       reg = __rh_find(rh, region);
-       read_unlock(&rh->hash_lock);
-
-       /* region hash entry should exist because write was in-flight */
-       BUG_ON(!reg);
-       BUG_ON(!list_empty(&reg->list));
-
-       spin_lock_irqsave(&rh->region_lock, flags);
-       /*
-        * Possible cases:
-        *   1) RH_DIRTY
-        *   2) RH_NOSYNC: was dirty, other preceeding writes failed
-        *   3) RH_RECOVERING: flushing pending writes
-        * Either case, the region should have not been connected to list.
-        */
-       recovering = (reg->state == RH_RECOVERING);
-       reg->state = RH_NOSYNC;
-       BUG_ON(!list_empty(&reg->list));
-       spin_unlock_irqrestore(&rh->region_lock, flags);
-
-       bio_endio(bio, error);
-       if (recovering)
-               complete_resync_work(reg, 0);
-}
 
 static void write_callback(unsigned long error, void *context)
 {
@@ -1119,7 +548,7 @@ static void write_callback(unsigned long error, void *context)
                bio_list_add(&ms->failures, bio);
                spin_unlock_irqrestore(&ms->lock, flags);
                if (should_wake)
-                       wake(ms);
+                       wakeup_mirrord(ms);
                return;
        }
 out:
@@ -1149,7 +578,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio)
         */
        bio_set_m(bio, get_default_mirror(ms));
 
-       (void) dm_io(&io_req, ms->nr_mirrors, io, NULL);
+       BUG_ON(dm_io(&io_req, ms->nr_mirrors, io, NULL));
 }
 
 static void do_writes(struct mirror_set *ms, struct bio_list *writes)
@@ -1169,18 +598,19 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
        bio_list_init(&recover);
 
        while ((bio = bio_list_pop(writes))) {
-               state = rh_state(&ms->rh, bio_to_region(&ms->rh, bio), 1);
+               state = dm_rh_get_state(ms->rh,
+                                       dm_rh_bio_to_region(ms->rh, bio), 1);
                switch (state) {
-               case RH_CLEAN:
-               case RH_DIRTY:
+               case DM_RH_CLEAN:
+               case DM_RH_DIRTY:
                        this_list = &sync;
                        break;
 
-               case RH_NOSYNC:
+               case DM_RH_NOSYNC:
                        this_list = &nosync;
                        break;
 
-               case RH_RECOVERING:
+               case DM_RH_RECOVERING:
                        this_list = &recover;
                        break;
                }
@@ -1193,9 +623,9 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
         * be written to (writes to recover regions are going to
         * be delayed).
         */
-       rh_inc_pending(&ms->rh, &sync);
-       rh_inc_pending(&ms->rh, &nosync);
-       ms->log_failure = rh_flush(&ms->rh) ? 1 : 0;
+       dm_rh_inc_pending(ms->rh, &sync);
+       dm_rh_inc_pending(ms->rh, &nosync);
+       ms->log_failure = dm_rh_flush(ms->rh) ? 1 : 0;
 
        /*
         * Dispatch io.
@@ -1204,13 +634,13 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes)
                spin_lock_irq(&ms->lock);
                bio_list_merge(&ms->failures, &sync);
                spin_unlock_irq(&ms->lock);
-               wake(ms);
+               wakeup_mirrord(ms);
        } else
                while ((bio = bio_list_pop(&sync)))
                        do_write(ms, bio);
 
        while ((bio = bio_list_pop(&recover)))
-               rh_delay(&ms->rh, bio);
+               dm_rh_delay(ms->rh, bio);
 
        while ((bio = bio_list_pop(&nosync))) {
                map_bio(get_default_mirror(ms), bio);
@@ -1227,7 +657,8 @@ static void do_failures(struct mirror_set *ms, struct bio_list *failures)
 
        if (!ms->log_failure) {
                while ((bio = bio_list_pop(failures)))
-                       __bio_mark_nosync(ms, bio, bio->bi_size, 0);
+                       ms->in_sync = 0;
+                       dm_rh_mark_nosync(ms->rh, bio, bio->bi_size, 0);
                return;
        }
 
@@ -1280,8 +711,8 @@ static void trigger_event(struct work_struct *work)
  *---------------------------------------------------------------*/
 static void do_mirror(struct work_struct *work)
 {
-       struct mirror_set *ms =container_of(work, struct mirror_set,
-                                           kmirrord_work);
+       struct mirror_set *ms = container_of(work, struct mirror_set,
+                                            kmirrord_work);
        struct bio_list reads, writes, failures;
        unsigned long flags;
 
@@ -1294,7 +725,7 @@ static void do_mirror(struct work_struct *work)
        bio_list_init(&ms->failures);
        spin_unlock_irqrestore(&ms->lock, flags);
 
-       rh_update_states(&ms->rh);
+       dm_rh_update_states(ms->rh, errors_handled(ms));
        do_recovery(ms);
        do_reads(ms, &reads);
        do_writes(ms, &writes);
@@ -1303,7 +734,6 @@ static void do_mirror(struct work_struct *work)
        dm_table_unplug_all(ms->ti->table);
 }
 
-
 /*-----------------------------------------------------------------
  * Target functions
  *---------------------------------------------------------------*/
@@ -1315,9 +745,6 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
        size_t len;
        struct mirror_set *ms = NULL;
 
-       if (array_too_big(sizeof(*ms), sizeof(ms->mirror[0]), nr_mirrors))
-               return NULL;
-
        len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
 
        ms = kzalloc(len, GFP_KERNEL);
@@ -1353,7 +780,11 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors,
                return NULL;
        }
 
-       if (rh_init(&ms->rh, ms, dl, region_size, ms->nr_regions)) {
+       ms->rh = dm_region_hash_create(ms, dispatch_bios, wakeup_mirrord,
+                                      wakeup_all_recovery_waiters,
+                                      ms->ti->begin, MAX_RECOVERY,
+                                      dl, region_size, ms->nr_regions);
+       if (IS_ERR(ms->rh)) {
                ti->error = "Error creating dirty region hash";
                dm_io_client_destroy(ms->io_client);
                mempool_destroy(ms->read_record_pool);
@@ -1371,7 +802,7 @@ static void free_context(struct mirror_set *ms, struct dm_target *ti,
                dm_put_device(ti, ms->mirror[m].dev);
 
        dm_io_client_destroy(ms->io_client);
-       rh_exit(&ms->rh);
+       dm_region_hash_destroy(ms->rh);
        mempool_destroy(ms->read_record_pool);
        kfree(ms);
 }
@@ -1411,10 +842,10 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
  * Create dirty log: log_type #log_params <log_params>
  */
 static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
-                                         unsigned int argc, char **argv,
-                                         unsigned int *args_used)
+                                            unsigned argc, char **argv,
+                                            unsigned *args_used)
 {
-       unsigned int param_count;
+       unsigned param_count;
        struct dm_dirty_log *dl;
 
        if (argc < 2) {
@@ -1545,7 +976,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
        }
 
        ti->private = ms;
-       ti->split_io = ms->rh.region_size;
+       ti->split_io = dm_rh_get_region_size(ms->rh);
 
        ms->kmirrord_wq = create_singlethread_workqueue("kmirrord");
        if (!ms->kmirrord_wq) {
@@ -1580,11 +1011,11 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                goto err_destroy_wq;
        }
 
-       r = dm_kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client);
+       r = dm_kcopyd_client_create(DM_KCOPYD_PAGES, &ms->kcopyd_client);
        if (r)
                goto err_destroy_wq;
 
-       wake(ms);
+       wakeup_mirrord(ms);
        return 0;
 
 err_destroy_wq:
@@ -1605,22 +1036,6 @@ static void mirror_dtr(struct dm_target *ti)
        free_context(ms, ti, ms->nr_mirrors);
 }
 
-static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
-{
-       unsigned long flags;
-       int should_wake = 0;
-       struct bio_list *bl;
-
-       bl = (rw == WRITE) ? &ms->writes : &ms->reads;
-       spin_lock_irqsave(&ms->lock, flags);
-       should_wake = !(bl->head);
-       bio_list_add(bl, bio);
-       spin_unlock_irqrestore(&ms->lock, flags);
-
-       if (should_wake)
-               wake(ms);
-}
-
 /*
  * Mirror mapping function
  */
@@ -1631,16 +1046,16 @@ static int mirror_map(struct dm_target *ti, struct bio *bio,
        struct mirror *m;
        struct mirror_set *ms = ti->private;
        struct dm_raid1_read_record *read_record = NULL;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
 
        if (rw == WRITE) {
                /* Save region for mirror_end_io() handler */
-               map_context->ll = bio_to_region(&ms->rh, bio);
+               map_context->ll = dm_rh_bio_to_region(ms->rh, bio);
                queue_bio(ms, bio, rw);
                return DM_MAPIO_SUBMITTED;
        }
 
-       r = ms->rh.log->type->in_sync(ms->rh.log,
-                                     bio_to_region(&ms->rh, bio), 0);
+       r = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0);
        if (r < 0 && r != -EWOULDBLOCK)
                return r;
 
@@ -1688,7 +1103,7 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio,
         * We need to dec pending if this was a write.
         */
        if (rw == WRITE) {
-               rh_dec(&ms->rh, map_context->ll);
+               dm_rh_dec(ms->rh, map_context->ll);
                return error;
        }
 
@@ -1744,7 +1159,7 @@ out:
 static void mirror_presuspend(struct dm_target *ti)
 {
        struct mirror_set *ms = (struct mirror_set *) ti->private;
-       struct dm_dirty_log *log = ms->rh.log;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
 
        atomic_set(&ms->suspend, 1);
 
@@ -1752,10 +1167,10 @@ static void mirror_presuspend(struct dm_target *ti)
         * We must finish up all the work that we've
         * generated (i.e. recovery work).
         */
-       rh_stop_recovery(&ms->rh);
+       dm_rh_stop_recovery(ms->rh);
 
        wait_event(_kmirrord_recovery_stopped,
-                  !atomic_read(&ms->rh.recovery_in_flight));
+                  !dm_rh_recovery_in_flight(ms->rh));
 
        if (log->type->presuspend && log->type->presuspend(log))
                /* FIXME: need better error handling */
@@ -1773,7 +1188,7 @@ static void mirror_presuspend(struct dm_target *ti)
 static void mirror_postsuspend(struct dm_target *ti)
 {
        struct mirror_set *ms = ti->private;
-       struct dm_dirty_log *log = ms->rh.log;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
 
        if (log->type->postsuspend && log->type->postsuspend(log))
                /* FIXME: need better error handling */
@@ -1783,13 +1198,13 @@ static void mirror_postsuspend(struct dm_target *ti)
 static void mirror_resume(struct dm_target *ti)
 {
        struct mirror_set *ms = ti->private;
-       struct dm_dirty_log *log = ms->rh.log;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
 
        atomic_set(&ms->suspend, 0);
        if (log->type->resume && log->type->resume(log))
                /* FIXME: need better error handling */
                DMWARN("log resume failed");
-       rh_start_recovery(&ms->rh);
+       dm_rh_start_recovery(ms->rh);
 }
 
 /*
@@ -1821,7 +1236,7 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
 {
        unsigned int m, sz = 0;
        struct mirror_set *ms = (struct mirror_set *) ti->private;
-       struct dm_dirty_log *log = ms->rh.log;
+       struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
        char buffer[ms->nr_mirrors + 1];
 
        switch (type) {
@@ -1834,15 +1249,15 @@ static int mirror_status(struct dm_target *ti, status_type_t type,
                buffer[m] = '\0';
 
                DMEMIT("%llu/%llu 1 %s ",
-                     (unsigned long long)log->type->get_sync_count(ms->rh.log),
+                     (unsigned long long)log->type->get_sync_count(log),
                      (unsigned long long)ms->nr_regions, buffer);
 
-               sz += log->type->status(ms->rh.log, type, result+sz, maxlen-sz);
+               sz += log->type->status(log, type, result+sz, maxlen-sz);
 
                break;
 
        case STATUSTYPE_TABLE:
-               sz = log->type->status(ms->rh.log, type, result, maxlen);
+               sz = log->type->status(log, type, result, maxlen);
 
                DMEMIT("%d", ms->nr_mirrors);
                for (m = 0; m < ms->nr_mirrors; m++)
diff --git a/drivers/md/dm-region-hash.c b/drivers/md/dm-region-hash.c
new file mode 100644 (file)
index 0000000..59f8d9d
--- /dev/null
@@ -0,0 +1,704 @@
+/*
+ * Copyright (C) 2003 Sistina Software Limited.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/dm-dirty-log.h>
+#include <linux/dm-region-hash.h>
+
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#include "dm.h"
+#include "dm-bio-list.h"
+
+#define        DM_MSG_PREFIX   "region hash"
+
+/*-----------------------------------------------------------------
+ * 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;
+
+       /* hash table */
+       rwlock_t hash_lock;
+       mempool_t *region_pool;
+       unsigned mask;
+       unsigned nr_buckets;
+       unsigned prime;
+       unsigned shift;
+       struct list_head *buckets;
+
+       unsigned max_recovery; /* Max # of regions to recover in parallel */
+
+       spinlock_t region_lock;
+       atomic_t recovery_in_flight;
+       struct semaphore recovery_count;
+       struct list_head clean_regions;
+       struct list_head quiesced_regions;
+       struct list_head recovered_regions;
+       struct list_head failed_recovered_regions;
+
+       void *context;
+       sector_t target_begin;
+
+       /* Callback function to schedule bios writes */
+       void (*dispatch_bios)(void *context, struct bio_list *bios);
+
+       /* Callback function to wakeup callers worker thread. */
+       void (*wakeup_workers)(void *context);
+
+       /* Callback function to wakeup callers recovery waiters. */
+       void (*wakeup_all_recovery_waiters)(void *context);
+};
+
+struct dm_region {
+       struct dm_region_hash *rh;      /* FIXME: can we get rid of this ? */
+       region_t key;
+       int state;
+
+       struct list_head hash_list;
+       struct list_head list;
+
+       atomic_t pending;
+       struct bio_list delayed_bios;
+};
+
+/*
+ * Conversion fns
+ */
+static region_t dm_rh_sector_to_region(struct dm_region_hash *rh, sector_t sector)
+{
+       return sector >> rh->region_shift;
+}
+
+sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region)
+{
+       return region << rh->region_shift;
+}
+EXPORT_SYMBOL_GPL(dm_rh_region_to_sector);
+
+region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio)
+{
+       return dm_rh_sector_to_region(rh, bio->bi_sector - rh->target_begin);
+}
+EXPORT_SYMBOL_GPL(dm_rh_bio_to_region);
+
+void *dm_rh_region_context(struct dm_region *reg)
+{
+       return reg->rh->context;
+}
+EXPORT_SYMBOL_GPL(dm_rh_region_context);
+
+region_t dm_rh_get_region_key(struct dm_region *reg)
+{
+       return reg->key;
+}
+EXPORT_SYMBOL_GPL(dm_rh_get_region_key);
+
+sector_t dm_rh_get_region_size(struct dm_region_hash *rh)
+{
+       return rh->region_size;
+}
+EXPORT_SYMBOL_GPL(dm_rh_get_region_size);
+
+/*
+ * FIXME: shall we pass in a structure instead of all these args to
+ * dm_region_hash_create()????
+ */
+#define RH_HASH_MULT 2654435387U
+#define RH_HASH_SHIFT 12
+
+#define MIN_REGIONS 64
+struct dm_region_hash *dm_region_hash_create(
+               void *context, void (*dispatch_bios)(void *context,
+                                                    struct bio_list *bios),
+               void (*wakeup_workers)(void *context),
+               void (*wakeup_all_recovery_waiters)(void *context),
+               sector_t target_begin, unsigned max_recovery,
+               struct dm_dirty_log *log, uint32_t region_size,
+               region_t nr_regions)
+{
+       struct dm_region_hash *rh;
+       unsigned nr_buckets, max_buckets;
+       size_t i;
+
+       /*
+        * Calculate a suitable number of buckets for our hash
+        * table.
+        */
+       max_buckets = nr_regions >> 6;
+       for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1)
+               ;
+       nr_buckets >>= 1;
+
+       rh = kmalloc(sizeof(*rh), GFP_KERNEL);
+       if (!rh) {
+               DMERR("unable to allocate region hash memory");
+               return ERR_PTR(-ENOMEM);
+       }
+
+       rh->context = context;
+       rh->dispatch_bios = dispatch_bios;
+       rh->wakeup_workers = wakeup_workers;
+       rh->wakeup_all_recovery_waiters = wakeup_all_recovery_waiters;
+       rh->target_begin = target_begin;
+       rh->max_recovery = max_recovery;
+       rh->log = log;
+       rh->region_size = region_size;
+       rh->region_shift = ffs(region_size) - 1;
+       rwlock_init(&rh->hash_lock);
+       rh->mask = nr_buckets - 1;
+       rh->nr_buckets = nr_buckets;
+
+       rh->shift = RH_HASH_SHIFT;
+       rh->prime = RH_HASH_MULT;
+
+       rh->buckets = vmalloc(nr_buckets * sizeof(*rh->buckets));
+       if (!rh->buckets) {
+               DMERR("unable to allocate region hash bucket memory");
+               kfree(rh);
+               return ERR_PTR(-ENOMEM);
+       }
+
+       for (i = 0; i < nr_buckets; i++)
+               INIT_LIST_HEAD(rh->buckets + i);
+
+       spin_lock_init(&rh->region_lock);
+       sema_init(&rh->recovery_count, 0);
+       atomic_set(&rh->recovery_in_flight, 0);
+       INIT_LIST_HEAD(&rh->clean_regions);
+       INIT_LIST_HEAD(&rh->quiesced_regions);
+       INIT_LIST_HEAD(&rh->recovered_regions);
+       INIT_LIST_HEAD(&rh->failed_recovered_regions);
+
+       rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
+                                                     sizeof(struct dm_region));
+       if (!rh->region_pool) {
+               vfree(rh->buckets);
+               kfree(rh);
+               rh = ERR_PTR(-ENOMEM);
+       }
+
+       return rh;
+}
+EXPORT_SYMBOL_GPL(dm_region_hash_create);
+
+void dm_region_hash_destroy(struct dm_region_hash *rh)
+{
+       unsigned h;
+       struct dm_region *reg, *nreg;
+
+       BUG_ON(!list_empty(&rh->quiesced_regions));
+       for (h = 0; h < rh->nr_buckets; h++) {
+               list_for_each_entry_safe(reg, nreg, rh->buckets + h,
+                                        hash_list) {
+                       BUG_ON(atomic_read(&reg->pending));
+                       mempool_free(reg, rh->region_pool);
+               }
+       }
+
+       if (rh->log)
+               dm_dirty_log_destroy(rh->log);
+
+       if (rh->region_pool)
+               mempool_destroy(rh->region_pool);
+
+       vfree(rh->buckets);
+       kfree(rh);
+}
+EXPORT_SYMBOL_GPL(dm_region_hash_destroy);
+
+struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh)
+{
+       return rh->log;
+}
+EXPORT_SYMBOL_GPL(dm_rh_dirty_log);
+
+static unsigned rh_hash(struct dm_region_hash *rh, region_t region)
+{
+       return (unsigned) ((region * rh->prime) >> rh->shift) & rh->mask;
+}
+
+static struct dm_region *__rh_lookup(struct dm_region_hash *rh, region_t region)
+{
+       struct dm_region *reg;
+       struct list_head *bucket = rh->buckets + rh_hash(rh, region);
+
+       list_for_each_entry(reg, bucket, hash_list)
+               if (reg->key == region)
+                       return reg;
+
+       return NULL;
+}
+
+static void __rh_insert(struct dm_region_hash *rh, struct dm_region *reg)
+{
+       list_add(&reg->hash_list, rh->buckets + rh_hash(rh, reg->key));
+}
+
+static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region)
+{
+       struct dm_region *reg, *nreg;
+
+       nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);
+       if (unlikely(!nreg))
+               nreg = kmalloc(sizeof(*nreg), GFP_NOIO);
+
+       nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
+                     DM_RH_CLEAN : DM_RH_NOSYNC;
+       nreg->rh = rh;
+       nreg->key = region;
+       INIT_LIST_HEAD(&nreg->list);
+       atomic_set(&nreg->pending, 0);
+       bio_list_init(&nreg->delayed_bios);
+
+       write_lock_irq(&rh->hash_lock);
+       reg = __rh_lookup(rh, region);
+       if (reg)
+               /* We lost the race. */
+               mempool_free(nreg, rh->region_pool);
+       else {
+               __rh_insert(rh, nreg);
+               if (nreg->state == DM_RH_CLEAN) {
+                       spin_lock(&rh->region_lock);
+                       list_add(&nreg->list, &rh->clean_regions);
+                       spin_unlock(&rh->region_lock);
+               }
+
+               reg = nreg;
+       }
+       write_unlock_irq(&rh->hash_lock);
+
+       return reg;
+}
+
+static struct dm_region *__rh_find(struct dm_region_hash *rh, region_t region)
+{
+       struct dm_region *reg;
+
+       reg = __rh_lookup(rh, region);
+       if (!reg) {
+               read_unlock(&rh->hash_lock);
+               reg = __rh_alloc(rh, region);
+               read_lock(&rh->hash_lock);
+       }
+
+       return reg;
+}
+
+int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block)
+{
+       int r;
+       struct dm_region *reg;
+
+       read_lock(&rh->hash_lock);
+       reg = __rh_lookup(rh, region);
+       read_unlock(&rh->hash_lock);
+
+       if (reg)
+               return reg->state;
+
+       /*
+        * The region wasn't in the hash, so we fall back to the
+        * dirty log.
+        */
+       r = rh->log->type->in_sync(rh->log, region, may_block);
+
+       /*
+        * Any error from the dirty log (eg. -EWOULDBLOCK) gets
+        * taken as a DM_RH_NOSYNC
+        */
+       return r == 1 ? DM_RH_CLEAN : DM_RH_NOSYNC;
+}
+EXPORT_SYMBOL_GPL(dm_rh_get_state);
+
+static void complete_resync_work(struct dm_region *reg, int success)
+{
+       struct dm_region_hash *rh = reg->rh;
+
+       rh->log->type->set_region_sync(rh->log, reg->key, success);
+
+       /*
+        * Dispatch the bios before we call 'wake_up_all'.
+        * This is important because if we are suspending,
+        * we want to know that recovery is complete and
+        * the work queue is flushed.  If we wake_up_all
+        * before we dispatch_bios (queue bios and call wake()),
+        * then we risk suspending before the work queue
+        * has been properly flushed.
+        */
+       rh->dispatch_bios(rh->context, &reg->delayed_bios);
+       if (atomic_dec_and_test(&rh->recovery_in_flight))
+               rh->wakeup_all_recovery_waiters(rh->context);
+       up(&rh->recovery_count);
+}
+
+/* dm_rh_mark_nosync
+ * @ms
+ * @bio
+ * @done
+ * @error
+ *
+ * The bio was written on some mirror(s) but failed on other mirror(s).
+ * We can successfully endio the bio but should avoid the region being
+ * marked clean by setting the state DM_RH_NOSYNC.
+ *
+ * This function is _not_ safe in interrupt context!
+ */
+void dm_rh_mark_nosync(struct dm_region_hash *rh,
+                      struct bio *bio, unsigned done, int error)
+{
+       unsigned long flags;
+       struct dm_dirty_log *log = rh->log;
+       struct dm_region *reg;
+       region_t region = dm_rh_bio_to_region(rh, bio);
+       int recovering = 0;
+
+       /* We must inform the log that the sync count has changed. */
+       log->type->set_region_sync(log, region, 0);
+
+       read_lock(&rh->hash_lock);
+       reg = __rh_find(rh, region);
+       read_unlock(&rh->hash_lock);
+
+       /* region hash entry should exist because write was in-flight */
+       BUG_ON(!reg);
+       BUG_ON(!list_empty(&reg->list));
+
+       spin_lock_irqsave(&rh->region_lock, flags);
+       /*
+        * Possible cases:
+        *   1) DM_RH_DIRTY
+        *   2) DM_RH_NOSYNC: was dirty, other preceeding writes failed
+        *   3) DM_RH_RECOVERING: flushing pending writes
+        * Either case, the region should have not been connected to list.
+        */
+       recovering = (reg->state == DM_RH_RECOVERING);
+       reg->state = DM_RH_NOSYNC;
+       BUG_ON(!list_empty(&reg->list));
+       spin_unlock_irqrestore(&rh->region_lock, flags);
+
+       bio_endio(bio, error);
+       if (recovering)
+               complete_resync_work(reg, 0);
+}
+EXPORT_SYMBOL_GPL(dm_rh_mark_nosync);
+
+void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled)
+{
+       struct dm_region *reg, *next;
+
+       LIST_HEAD(clean);
+       LIST_HEAD(recovered);
+       LIST_HEAD(failed_recovered);
+
+       /*
+        * Quickly grab the lists.
+        */
+       write_lock_irq(&rh->hash_lock);
+       spin_lock(&rh->region_lock);
+       if (!list_empty(&rh->clean_regions)) {
+               list_splice_init(&rh->clean_regions, &clean);
+
+               list_for_each_entry(reg, &clean, list)
+                       list_del(&reg->hash_list);
+       }
+
+       if (!list_empty(&rh->recovered_regions)) {
+               list_splice_init(&rh->recovered_regions, &recovered);
+
+               list_for_each_entry(reg, &recovered, list)
+                       list_del(&reg->hash_list);
+       }
+
+       if (!list_empty(&rh->failed_recovered_regions)) {
+               list_splice_init(&rh->failed_recovered_regions,
+                                &failed_recovered);
+
+               list_for_each_entry(reg, &failed_recovered, list)
+                       list_del(&reg->hash_list);
+       }
+
+       spin_unlock(&rh->region_lock);
+       write_unlock_irq(&rh->hash_lock);
+
+       /*
+        * All the regions on the recovered and clean lists have
+        * now been pulled out of the system, so no need to do
+        * any more locking.
+        */
+       list_for_each_entry_safe(reg, next, &recovered, list) {
+               rh->log->type->clear_region(rh->log, reg->key);
+               complete_resync_work(reg, 1);
+               mempool_free(reg, rh->region_pool);
+       }
+
+       list_for_each_entry_safe(reg, next, &failed_recovered, list) {
+               complete_resync_work(reg, errors_handled ? 0 : 1);
+               mempool_free(reg, rh->region_pool);
+       }
+
+       list_for_each_entry_safe(reg, next, &clean, list) {
+               rh->log->type->clear_region(rh->log, reg->key);
+               mempool_free(reg, rh->region_pool);
+       }
+
+       rh->log->type->flush(rh->log);
+}
+EXPORT_SYMBOL_GPL(dm_rh_update_states);
+
+static void rh_inc(struct dm_region_hash *rh, region_t region)
+{
+       struct dm_region *reg;
+
+       read_lock(&rh->hash_lock);
+       reg = __rh_find(rh, region);
+
+       spin_lock_irq(&rh->region_lock);
+       atomic_inc(&reg->pending);
+
+       if (reg->state == DM_RH_CLEAN) {
+               reg->state = DM_RH_DIRTY;
+               list_del_init(&reg->list);      /* take off the clean list */
+               spin_unlock_irq(&rh->region_lock);
+
+               rh->log->type->mark_region(rh->log, reg->key);
+       } else
+               spin_unlock_irq(&rh->region_lock);
+
+
+       read_unlock(&rh->hash_lock);
+}
+
+void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
+{
+       struct bio *bio;
+
+       for (bio = bios->head; bio; bio = bio->bi_next)
+               rh_inc(rh, dm_rh_bio_to_region(rh, bio));
+}
+EXPORT_SYMBOL_GPL(dm_rh_inc_pending);
+
+void dm_rh_dec(struct dm_region_hash *rh, region_t region)
+{
+       unsigned long flags;
+       struct dm_region *reg;
+       int should_wake = 0;
+
+       read_lock(&rh->hash_lock);
+       reg = __rh_lookup(rh, region);
+       read_unlock(&rh->hash_lock);
+
+       spin_lock_irqsave(&rh->region_lock, flags);
+       if (atomic_dec_and_test(&reg->pending)) {
+               /*
+                * There is no pending I/O for this region.
+                * We can move the region to corresponding list for next action.
+                * At this point, the region is not yet connected to any list.
+                *
+                * If the state is DM_RH_NOSYNC, the region should be kept off
+                * from clean list.
+                * The hash entry for DM_RH_NOSYNC will remain in memory
+                * until the region is recovered or the map is reloaded.
+                */
+
+               /* do nothing for DM_RH_NOSYNC */
+               if (reg->state == DM_RH_RECOVERING) {
+                       list_add_tail(&reg->list, &rh->quiesced_regions);
+               } else if (reg->state == DM_RH_DIRTY) {
+                       reg->state = DM_RH_CLEAN;
+                       list_add(&reg->list, &rh->clean_regions);
+               }
+               should_wake = 1;
+       }
+       spin_unlock_irqrestore(&rh->region_lock, flags);
+
+       if (should_wake)
+               rh->wakeup_workers(rh->context);
+}
+EXPORT_SYMBOL_GPL(dm_rh_dec);
+
+/*
+ * Starts quiescing a region in preparation for recovery.
+ */
+static int __rh_recovery_prepare(struct dm_region_hash *rh)
+{
+       int r;
+       region_t region;
+       struct dm_region *reg;
+
+       /*
+        * Ask the dirty log what's next.
+        */
+       r = rh->log->type->get_resync_work(rh->log, &region);
+       if (r <= 0)
+               return r;
+
+       /*
+        * Get this region, and start it quiescing by setting the
+        * recovering flag.
+        */
+       read_lock(&rh->hash_lock);
+       reg = __rh_find(rh, region);
+       read_unlock(&rh->hash_lock);
+
+       spin_lock_irq(&rh->region_lock);
+       reg->state = DM_RH_RECOVERING;
+
+       /* Already quiesced ? */
+       if (atomic_read(&reg->pending))
+               list_del_init(&reg->list);
+       else
+               list_move(&reg->list, &rh->quiesced_regions);
+
+       spin_unlock_irq(&rh->region_lock);
+
+       return 1;
+}
+
+void dm_rh_recovery_prepare(struct dm_region_hash *rh)
+{
+       /* Extra reference to avoid race with dm_rh_stop_recovery */
+       atomic_inc(&rh->recovery_in_flight);
+
+       while (!down_trylock(&rh->recovery_count)) {
+               atomic_inc(&rh->recovery_in_flight);
+               if (__rh_recovery_prepare(rh) <= 0) {
+                       atomic_dec(&rh->recovery_in_flight);
+                       up(&rh->recovery_count);
+                       break;
+               }
+       }
+
+       /* Drop the extra reference */
+       if (atomic_dec_and_test(&rh->recovery_in_flight))
+               rh->wakeup_all_recovery_waiters(rh->context);
+}
+EXPORT_SYMBOL_GPL(dm_rh_recovery_prepare);
+
+/*
+ * Returns any quiesced regions.
+ */
+struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh)
+{
+       struct dm_region *reg = NULL;
+
+       spin_lock_irq(&rh->region_lock);
+       if (!list_empty(&rh->quiesced_regions)) {
+               reg = list_entry(rh->quiesced_regions.next,
+                                struct dm_region, list);
+               list_del_init(&reg->list);  /* remove from the quiesced list */
+       }
+       spin_unlock_irq(&rh->region_lock);
+
+       return reg;
+}
+EXPORT_SYMBOL_GPL(dm_rh_recovery_start);
+
+void dm_rh_recovery_end(struct dm_region *reg, int success)
+{
+       struct dm_region_hash *rh = reg->rh;
+
+       spin_lock_irq(&rh->region_lock);
+       if (success)
+               list_add(&reg->list, &reg->rh->recovered_regions);
+       else {
+               reg->state = DM_RH_NOSYNC;
+               list_add(&reg->list, &reg->rh->failed_recovered_regions);
+       }
+       spin_unlock_irq(&rh->region_lock);
+
+       rh->wakeup_workers(rh->context);
+}
+EXPORT_SYMBOL_GPL(dm_rh_recovery_end);
+
+/* Return recovery in flight count. */
+int dm_rh_recovery_in_flight(struct dm_region_hash *rh)
+{
+       return atomic_read(&rh->recovery_in_flight);
+}
+EXPORT_SYMBOL_GPL(dm_rh_recovery_in_flight);
+
+int dm_rh_flush(struct dm_region_hash *rh)
+{
+       return rh->log->type->flush(rh->log);
+}
+EXPORT_SYMBOL_GPL(dm_rh_flush);
+
+void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio)
+{
+       struct dm_region *reg;
+
+       read_lock(&rh->hash_lock);
+       reg = __rh_find(rh, dm_rh_bio_to_region(rh, bio));
+       bio_list_add(&reg->delayed_bios, bio);
+       read_unlock(&rh->hash_lock);
+}
+EXPORT_SYMBOL_GPL(dm_rh_delay);
+
+void dm_rh_stop_recovery(struct dm_region_hash *rh)
+{
+       int i;
+
+       /* wait for any recovering regions */
+       for (i = 0; i < rh->max_recovery; i++)
+               down(&rh->recovery_count);
+}
+EXPORT_SYMBOL_GPL(dm_rh_stop_recovery);
+
+void dm_rh_start_recovery(struct dm_region_hash *rh)
+{
+       int i;
+
+       for (i = 0; i < rh->max_recovery; i++)
+               up(&rh->recovery_count);
+
+       rh->wakeup_workers(rh->context);
+}
+EXPORT_SYMBOL_GPL(dm_rh_start_recovery);
+
+MODULE_DESCRIPTION(DM_NAME " region hash");
+MODULE_AUTHOR("Joe Thornber/Heinz Mauelshagen <dm-devel@redhat.com>");
+MODULE_LICENSE("GPL");
index 391dfa2ad4347a690d8bc4636515ebfff39a5f08..cdfbf65b28cb0fb5d4af95d9e6718d80d69be760 100644 (file)
@@ -9,7 +9,8 @@
  * Round-robin path selector.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
+
 #include "dm-path-selector.h"
 
 #include <linux/slab.h>
index 6e5528aecc98c38698a6d2a07a18e1e84164a7ab..b2d9d1ac28adb4554537fd3568ae4fe52e748a41 100644 (file)
@@ -600,7 +600,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
        s->valid = 1;
        s->active = 0;
-       s->last_percent = 0;
        init_rwsem(&s->lock);
        spin_lock_init(&s->pe_lock);
        s->ti = ti;
@@ -824,8 +823,10 @@ static struct bio *put_pending_exception(struct dm_snap_pending_exception *pe)
         * the bios for the original write to the origin.
         */
        if (primary_pe &&
-           atomic_dec_and_test(&primary_pe->ref_count))
+           atomic_dec_and_test(&primary_pe->ref_count)) {
                origin_bios = bio_list_get(&primary_pe->origin_bios);
+               free_pending_exception(primary_pe);
+       }
 
        /*
         * Free the pe if it's not linked to an origin write or if
@@ -834,12 +835,6 @@ static struct bio *put_pending_exception(struct dm_snap_pending_exception *pe)
        if (!primary_pe || primary_pe != pe)
                free_pending_exception(pe);
 
-       /*
-        * Free the primary pe if nothing references it.
-        */
-       if (primary_pe && !atomic_read(&primary_pe->ref_count))
-               free_pending_exception(primary_pe);
-
        return origin_bios;
 }
 
index 292c15609ae362fc344a9c46811285319a3f1bec..f07315fe23621e706bae67ab240d2bb8d89c42d3 100644 (file)
@@ -9,7 +9,7 @@
 #ifndef DM_SNAPSHOT_H
 #define DM_SNAPSHOT_H
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 #include "dm-bio-list.h"
 #include <linux/blkdev.h>
 #include <linux/workqueue.h>
@@ -158,9 +158,6 @@ struct dm_snapshot {
        /* Used for display of table */
        char type;
 
-       /* The last percentage we notified */
-       int last_percent;
-
        mempool_t *pending_pool;
 
        struct exception_table pending;
index b745d8ac625b5ffd6730f585e95fec2081cf8429..a2d068dbe9e2669dc25290a09e8918b4b5c2f28f 100644 (file)
@@ -4,7 +4,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/module.h>
 #include <linux/init.h>
@@ -60,8 +60,8 @@ static inline struct stripe_c *alloc_context(unsigned int stripes)
 {
        size_t len;
 
-       if (array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
-                         stripes))
+       if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
+                            stripes))
                return NULL;
 
        len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
index bdec206c404bcbbe70db8ce82546072dd8ea9ee0..cdbf126ec10651f6632bfed0401598e3ced361d5 100644 (file)
@@ -4,7 +4,7 @@
  * This file is released under the GPL.
  */
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #include <linux/module.h>
 #include <linux/init.h>
index 327de03a5bdfed7f11b0904abb72f3eac65fc92d..d1d0cd0f5750a2693f29cdf7bf5e5d99cbbfa2c0 100644 (file)
@@ -76,7 +76,6 @@ union map_info *dm_get_mapinfo(struct bio *bio)
  */
 struct dm_wq_req {
        enum {
-               DM_WQ_FLUSH_ALL,
                DM_WQ_FLUSH_DEFERRED,
        } type;
        struct work_struct work;
@@ -151,40 +150,40 @@ static struct kmem_cache *_tio_cache;
 
 static int __init local_init(void)
 {
-       int r;
+       int r = -ENOMEM;
 
        /* allocate a slab for the dm_ios */
        _io_cache = KMEM_CACHE(dm_io, 0);
        if (!_io_cache)
-               return -ENOMEM;
+               return r;
 
        /* allocate a slab for the target ios */
        _tio_cache = KMEM_CACHE(dm_target_io, 0);
-       if (!_tio_cache) {
-               kmem_cache_destroy(_io_cache);
-               return -ENOMEM;
-       }
+       if (!_tio_cache)
+               goto out_free_io_cache;
 
        r = dm_uevent_init();
-       if (r) {
-               kmem_cache_destroy(_tio_cache);
-               kmem_cache_destroy(_io_cache);
-               return r;
-       }
+       if (r)
+               goto out_free_tio_cache;
 
        _major = major;
        r = register_blkdev(_major, _name);
-       if (r < 0) {
-               kmem_cache_destroy(_tio_cache);
-               kmem_cache_destroy(_io_cache);
-               dm_uevent_exit();
-               return r;
-       }
+       if (r < 0)
+               goto out_uevent_exit;
 
        if (!_major)
                _major = r;
 
        return 0;
+
+out_uevent_exit:
+       dm_uevent_exit();
+out_free_tio_cache:
+       kmem_cache_destroy(_tio_cache);
+out_free_io_cache:
+       kmem_cache_destroy(_io_cache);
+
+       return r;
 }
 
 static void local_exit(void)
@@ -669,6 +668,7 @@ static struct bio *split_bvec(struct bio *bio, sector_t sector,
        clone->bi_size = to_bytes(len);
        clone->bi_io_vec->bv_offset = offset;
        clone->bi_io_vec->bv_len = clone->bi_size;
+       clone->bi_flags |= 1 << BIO_CLONED;
 
        return clone;
 }
@@ -1394,9 +1394,6 @@ static void dm_wq_work(struct work_struct *work)
 
        down_write(&md->io_lock);
        switch (req->type) {
-       case DM_WQ_FLUSH_ALL:
-               __merge_pushback_list(md);
-               /* pass through */
        case DM_WQ_FLUSH_DEFERRED:
                __flush_deferred_io(md);
                break;
@@ -1526,7 +1523,7 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
                if (!md->suspended_bdev) {
                        DMWARN("bdget failed in dm_suspend");
                        r = -ENOMEM;
-                       goto flush_and_out;
+                       goto out;
                }
 
                /*
@@ -1577,14 +1574,6 @@ int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
 
        set_bit(DMF_SUSPENDED, &md->flags);
 
-flush_and_out:
-       if (r && noflush)
-               /*
-                * Because there may be already I/Os in the pushback list,
-                * flush them before return.
-                */
-               dm_queue_flush(md, DM_WQ_FLUSH_ALL, NULL);
-
 out:
        if (r && md->suspended_bdev) {
                bdput(md->suspended_bdev);
index cd189da2b2fa1fbad7293f152f0744b7bdbb8c35..0ade60cdef42dd062bf8f11210ee27b65dd651d2 100644 (file)
@@ -62,15 +62,6 @@ void dm_put_target_type(struct target_type *t);
 int dm_target_iterate(void (*iter_func)(struct target_type *tt,
                                        void *param), void *param);
 
-/*-----------------------------------------------------------------
- * Useful inlines.
- *---------------------------------------------------------------*/
-static inline int array_too_big(unsigned long fixed, unsigned long obj,
-                               unsigned long num)
-{
-       return (num > (ULONG_MAX - fixed) / obj);
-}
-
 int dm_split_args(int *argc, char ***argvp, char *input);
 
 /*
index 08d783592b73ef4ef6bf8f2b03c8b1359ebe5b40..dfb30db475ed61c2c5562952c3e8add25a1754a2 100644 (file)
@@ -354,6 +354,9 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
  */
 #define dm_round_up(n, sz) (dm_div_up((n), (sz)) * (sz))
 
+#define dm_array_too_big(fixed, obj, num) \
+       ((num) > (UINT_MAX - (fixed)) / (obj))
+
 static inline sector_t to_sector(unsigned long n)
 {
        return (n >> SECTOR_SHIFT);
diff --git a/include/linux/dm-region-hash.h b/include/linux/dm-region-hash.h
new file mode 100644 (file)
index 0000000..a9e652a
--- /dev/null
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2003 Sistina Software Limited.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper dirty region hash interface.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef DM_REGION_HASH_H
+#define DM_REGION_HASH_H
+
+#include <linux/dm-dirty-log.h>
+
+/*-----------------------------------------------------------------
+ * Region hash
+ *----------------------------------------------------------------*/
+struct dm_region_hash;
+struct dm_region;
+
+/*
+ * States a region can have.
+ */
+enum dm_rh_region_states {
+       DM_RH_CLEAN      = 0x01,        /* No writes in flight. */
+       DM_RH_DIRTY      = 0x02,        /* Writes in flight. */
+       DM_RH_NOSYNC     = 0x04,        /* Out of sync. */
+       DM_RH_RECOVERING = 0x08,        /* Under resynchronization. */
+};
+
+/*
+ * Region hash create/destroy.
+ */
+struct bio_list;
+struct dm_region_hash *dm_region_hash_create(
+               void *context, void (*dispatch_bios)(void *context,
+                                                    struct bio_list *bios),
+               void (*wakeup_workers)(void *context),
+               void (*wakeup_all_recovery_waiters)(void *context),
+               sector_t target_begin, unsigned max_recovery,
+               struct dm_dirty_log *log, uint32_t region_size,
+               region_t nr_regions);
+void dm_region_hash_destroy(struct dm_region_hash *rh);
+
+struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh);
+
+/*
+ * Conversion functions.
+ */
+region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio);
+sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region);
+void *dm_rh_region_context(struct dm_region *reg);
+
+/*
+ * Get region size and key (ie. number of the region).
+ */
+sector_t dm_rh_get_region_size(struct dm_region_hash *rh);
+region_t dm_rh_get_region_key(struct dm_region *reg);
+
+/*
+ * Get/set/update region state (and dirty log).
+ *
+ */
+int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block);
+void dm_rh_set_state(struct dm_region_hash *rh, region_t region,
+                    enum dm_rh_region_states state, int may_block);
+
+/* Non-zero errors_handled leaves the state of the region NOSYNC */
+void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled);
+
+/* Flush the region hash and dirty log. */
+int dm_rh_flush(struct dm_region_hash *rh);
+
+/* Inc/dec pending count on regions. */
+void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios);
+void dm_rh_dec(struct dm_region_hash *rh, region_t region);
+
+/* Delay bios on regions. */
+void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio);
+
+void dm_rh_mark_nosync(struct dm_region_hash *rh,
+                      struct bio *bio, unsigned done, int error);
+
+/*
+ * Region recovery control.
+ */
+
+/* Prepare some regions for recovery by starting to quiesce them. */
+void dm_rh_recovery_prepare(struct dm_region_hash *rh);
+
+/* Try fetching a quiesced region for recovery. */
+struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh);
+
+/* Report recovery end on a region. */
+void dm_rh_recovery_end(struct dm_region *reg, int error);
+
+/* Returns number of regions with recovery work outstanding. */
+int dm_rh_recovery_in_flight(struct dm_region_hash *rh);
+
+/* Start/stop recovery. */
+void dm_rh_start_recovery(struct dm_region_hash *rh);
+void dm_rh_stop_recovery(struct dm_region_hash *rh);
+
+#endif /* DM_REGION_HASH_H */