1 files changed, 11 insertions, 71 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 5974d3094d97..9ecff5f3023a 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -19,7 +19,6 @@
 #include <linux/vmalloc.h>
 #include <linux/log2.h>
 #include <linux/dm-kcopyd.h>
-#include <linux/workqueue.h>
 
 #include "dm-exception-store.h"
 
@@ -41,11 +40,6 @@ static const char dm_snapshot_merge_target_name[] = "snapshot-merge";
 #define SNAPSHOT_COPY_PRIORITY 2
 
 /*
- * Reserve 1MB for each snapshot initially (with minimum of 1 page).
- */
-#define SNAPSHOT_PAGES (((1UL << 20) >> PAGE_SHIFT) ? : 1)
-
-/*
  * The size of the mempool used to track chunks in use.
  */
 #define MIN_IOS 256
@@ -80,9 +74,6 @@ struct dm_snapshot {
         /* Origin writes don't trigger exceptions until this is set */
         int active;
 
-        /* Whether or not owning mapped_device is suspended */
-        int suspended;
-
         atomic_t pending_exceptions_count;
 
         mempool_t *pending_pool;
@@ -106,10 +97,6 @@ struct dm_snapshot {
 
         struct dm_kcopyd_client *kcopyd_client;
 
-        /* Queue of snapshot writes for ksnapd to flush */
-        struct bio_list queued_bios;
-        struct work_struct queued_bios_work;
-
         /* Wait for events based on state_bits */
         unsigned long state_bits;
 
@@ -160,9 +147,6 @@ struct dm_dev *dm_snap_cow(struct dm_snapshot *s)
 }
 EXPORT_SYMBOL(dm_snap_cow);
 
-static struct workqueue_struct *ksnapd;
-static void flush_queued_bios(struct work_struct *work);
-
 static sector_t chunk_to_sector(struct dm_exception_store *store,
                                 chunk_t chunk)
 {
@@ -706,8 +690,6 @@ static int dm_add_exception(void *context, chunk_t old, chunk_t new)
         return 0;
 }
 
-#define min_not_zero(l, r) (((l) == 0) ? (r) : (((r) == 0) ? (l) : min(l, r)))
-
 /*
  * Return a minimum chunk size of all snapshots that have the specified origin.
  * Return zero if the origin has no snapshots.
@@ -1093,7 +1075,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         argv++;
         argc--;
 
-        r = dm_get_device(ti, cow_path, FMODE_READ | FMODE_WRITE, &s->cow);
+        r = dm_get_device(ti, cow_path, dm_table_get_mode(ti->table), &s->cow);
         if (r) {
                 ti->error = "Cannot get COW device";
                 goto bad_cow;
@@ -1112,7 +1094,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         s->ti = ti;
         s->valid = 1;
         s->active = 0;
-        s->suspended = 0;
         atomic_set(&s->pending_exceptions_count, 0);
         init_rwsem(&s->lock);
         INIT_LIST_HEAD(&s->list);
@@ -1130,8 +1111,9 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad_hash_tables;
         }
 
-        r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client);
-        if (r) {
+        s->kcopyd_client = dm_kcopyd_client_create();
+        if (IS_ERR(s->kcopyd_client)) {
+                r = PTR_ERR(s->kcopyd_client);
                 ti->error = "Could not create kcopyd client";
                 goto bad_kcopyd;
         }
@@ -1155,9 +1137,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
         spin_lock_init(&s->tracked_chunk_lock);
 
-        bio_list_init(&s->queued_bios);
-        INIT_WORK(&s->queued_bios_work, flush_queued_bios);
-
         ti->private = s;
         ti->num_flush_requests = num_flush_requests;
 
@@ -1281,8 +1260,6 @@ static void snapshot_dtr(struct dm_target *ti)
         struct dm_snapshot *s = ti->private;
         struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
 
-        flush_workqueue(ksnapd);
-
         down_read(&_origins_lock);
         /* Check whether exception handover must be cancelled */
         (void) __find_snapshots_sharing_cow(s, &snap_src, &snap_dest, NULL);
@@ -1344,20 +1321,6 @@ static void flush_bios(struct bio *bio)
         }
 }
 
-static void flush_queued_bios(struct work_struct *work)
-{
-        struct dm_snapshot *s =
-                container_of(work, struct dm_snapshot, queued_bios_work);
-        struct bio *queued_bios;
-        unsigned long flags;
-
-        spin_lock_irqsave(&s->pe_lock, flags);
-        queued_bios = bio_list_get(&s->queued_bios);
-        spin_unlock_irqrestore(&s->pe_lock, flags);
-
-        flush_bios(queued_bios);
-}
-
 static int do_origin(struct dm_dev *origin, struct bio *bio);
 
 /*
@@ -1587,7 +1550,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
         chunk_t chunk;
         struct dm_snap_pending_exception *pe = NULL;
 
-        if (unlikely(bio_empty_barrier(bio))) {
+        if (bio->bi_rw & REQ_FLUSH) {
                 bio->bi_bdev = s->cow->bdev;
                 return DM_MAPIO_REMAPPED;
         }
@@ -1691,7 +1654,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
         int r = DM_MAPIO_REMAPPED;
         chunk_t chunk;
 
-        if (unlikely(bio_empty_barrier(bio))) {
+        if (bio->bi_rw & REQ_FLUSH) {
                 if (!map_context->target_request_nr)
                         bio->bi_bdev = s->origin->bdev;
                 else
@@ -1762,15 +1725,6 @@ static void snapshot_merge_presuspend(struct dm_target *ti)
         stop_merge(s);
 }
 
-static void snapshot_postsuspend(struct dm_target *ti)
-{
-        struct dm_snapshot *s = ti->private;
-
-        down_write(&s->lock);
-        s->suspended = 1;
-        up_write(&s->lock);
-}
-
 static int snapshot_preresume(struct dm_target *ti)
 {
         int r = 0;
@@ -1785,7 +1739,7 @@ static int snapshot_preresume(struct dm_target *ti)
                         DMERR("Unable to resume snapshot source until "
                               "handover completes.");
                         r = -EINVAL;
-                } else if (!snap_src->suspended) {
+                } else if (!dm_suspended(snap_src->ti)) {
                         DMERR("Unable to perform snapshot handover until "
                               "source is suspended.");
                         r = -EINVAL;
@@ -1818,7 +1772,6 @@ static void snapshot_resume(struct dm_target *ti)
 
         down_write(&s->lock);
         s->active = 1;
-        s->suspended = 0;
         up_write(&s->lock);
 }
 
@@ -2135,7 +2088,7 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
         struct dm_dev *dev = ti->private;
         bio->bi_bdev = dev->bdev;
 
-        if (unlikely(bio_empty_barrier(bio)))
+        if (bio->bi_rw & REQ_FLUSH)
                 return DM_MAPIO_REMAPPED;
 
         /* Only tell snapshots if this is a write */
@@ -2196,7 +2149,7 @@ static int origin_iterate_devices(struct dm_target *ti,
 
 static struct target_type origin_target = {
         .name    = "snapshot-origin",
-        .version = {1, 7, 0},
+        .version = {1, 7, 1},
         .module  = THIS_MODULE,
         .ctr     = origin_ctr,
         .dtr     = origin_dtr,
@@ -2209,13 +2162,12 @@ static struct target_type origin_target = {
 
 static struct target_type snapshot_target = {
         .name    = "snapshot",
-        .version = {1, 9, 0},
+        .version = {1, 10, 0},
         .module  = THIS_MODULE,
         .ctr     = snapshot_ctr,
         .dtr     = snapshot_dtr,
         .map     = snapshot_map,
         .end_io  = snapshot_end_io,
-        .postsuspend = snapshot_postsuspend,
         .preresume  = snapshot_preresume,
         .resume  = snapshot_resume,
         .status  = snapshot_status,
@@ -2224,14 +2176,13 @@ static struct target_type snapshot_target = {
 
 static struct target_type merge_target = {
         .name    = dm_snapshot_merge_target_name,
-        .version = {1, 0, 0},
+        .version = {1, 1, 0},
         .module  = THIS_MODULE,
         .ctr     = snapshot_ctr,
         .dtr     = snapshot_dtr,
         .map     = snapshot_merge_map,
         .end_io  = snapshot_end_io,
         .presuspend = snapshot_merge_presuspend,
-        .postsuspend = snapshot_postsuspend,
         .preresume  = snapshot_preresume,
         .resume  = snapshot_merge_resume,
         .status  = snapshot_status,
@@ -2293,17 +2244,8 @@ static int __init dm_snapshot_init(void)
                 goto bad_tracked_chunk_cache;
         }
 
-        ksnapd = create_singlethread_workqueue("ksnapd");
-        if (!ksnapd) {
-                DMERR("Failed to create ksnapd workqueue.");
-                r = -ENOMEM;
-                goto bad_pending_pool;
-        }
-
         return 0;
 
-bad_pending_pool:
-        kmem_cache_destroy(tracked_chunk_cache);
 bad_tracked_chunk_cache:
         kmem_cache_destroy(pending_cache);
 bad_pending_cache:
@@ -2324,8 +2266,6 @@ bad_register_snapshot_target:
 
 static void __exit dm_snapshot_exit(void)
 {
-        destroy_workqueue(ksnapd);
-
         dm_unregister_target(&snapshot_target);
         dm_unregister_target(&origin_target);
         dm_unregister_target(&merge_target);