Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

1 files changed, 132 insertions, 75 deletions

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index f9fc07d7a4b9..451c3bb176d2 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -55,6 +55,7 @@ struct dm_table {
         struct dm_target *targets;
 
         unsigned discards_supported:1;
+        unsigned integrity_supported:1;
 
         /*
          * Indicates the rw permissions for the new logical
@@ -71,6 +72,8 @@ struct dm_table {
         void *event_context;
 
         struct dm_md_mempools *mempools;
+
+        struct list_head target_callbacks;
 };
 
 /*
@@ -204,6 +207,7 @@ int dm_table_create(struct dm_table **result, fmode_t mode,
                 return -ENOMEM;
 
         INIT_LIST_HEAD(&t->devices);
+        INIT_LIST_HEAD(&t->target_callbacks);
         atomic_set(&t->holders, 0);
         t->discards_supported = 1;
 
@@ -325,15 +329,18 @@ static int open_dev(struct dm_dev_internal *d, dev_t dev,
 
         BUG_ON(d->dm_dev.bdev);
 
-        bdev = open_by_devnum(dev, d->dm_dev.mode);
+        bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
         if (IS_ERR(bdev))
                 return PTR_ERR(bdev);
-        r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
-        if (r)
-                blkdev_put(bdev, d->dm_dev.mode);
-        else
-                d->dm_dev.bdev = bdev;
-        return r;
+
+        r = bd_link_disk_holder(bdev, dm_disk(md));
+        if (r) {
+                blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
+                return r;
+        }
+
+        d->dm_dev.bdev = bdev;
+        return 0;
 }
 
 /*
@@ -344,8 +351,8 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
         if (!d->dm_dev.bdev)
                 return;
 
-        bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
-        blkdev_put(d->dm_dev.bdev, d->dm_dev.mode);
+        bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
+        blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
         d->dm_dev.bdev = NULL;
 }
 
@@ -355,6 +362,7 @@ static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
                                   sector_t start, sector_t len, void *data)
 {
+        struct request_queue *q;
         struct queue_limits *limits = data;
         struct block_device *bdev = dev->bdev;
         sector_t dev_size =
@@ -363,6 +371,22 @@ static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
                 limits->logical_block_size >> SECTOR_SHIFT;
         char b[BDEVNAME_SIZE];
 
+        /*
+         * Some devices exist without request functions,
+         * such as loop devices not yet bound to backing files.
+         * Forbid the use of such devices.
+         */
+        q = bdev_get_queue(bdev);
+        if (!q || !q->make_request_fn) {
+                DMWARN("%s: %s is not yet initialised: "
+                       "start=%llu, len=%llu, dev_size=%llu",
+                       dm_device_name(ti->table->md), bdevname(bdev, b),
+                       (unsigned long long)start,
+                       (unsigned long long)len,
+                       (unsigned long long)dev_size);
+                return 1;
+        }
+
         if (!dev_size)
                 return 0;
 
@@ -486,11 +510,6 @@ static int __table_get_device(struct dm_table *t, struct dm_target *ti,
         return 0;
 }
 
-/*
- * Returns the minimum that is _not_ zero, unless both are zero.
- */
-#define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r))
-
 int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
                          sector_t start, sector_t len, void *data)
 {
@@ -522,9 +541,8 @@ int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
          */
 
         if (q->merge_bvec_fn && !ti->type->merge)
-                limits->max_sectors =
-                        min_not_zero(limits->max_sectors,
-                                     (unsigned int) (PAGE_SIZE >> 9));
+                blk_limits_max_hw_sectors(limits,
+                                          (unsigned int) (PAGE_SIZE >> 9));
         return 0;
 }
 EXPORT_SYMBOL_GPL(dm_set_device_limits);
@@ -859,7 +877,7 @@ int dm_table_alloc_md_mempools(struct dm_table *t)
                 return -EINVAL;
         }
 
-        t->mempools = dm_alloc_md_mempools(type);
+        t->mempools = dm_alloc_md_mempools(type, t->integrity_supported);
         if (!t->mempools)
                 return -ENOMEM;
 
@@ -926,18 +944,80 @@ static int dm_table_build_index(struct dm_table *t)
 }
 
 /*
+ * Get a disk whose integrity profile reflects the table's profile.
+ * If %match_all is true, all devices' profiles must match.
+ * If %match_all is false, all devices must at least have an
+ * allocated integrity profile; but uninitialized is ok.
+ * Returns NULL if integrity support was inconsistent or unavailable.
+ */
+static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
+                                                    bool match_all)
+{
+        struct list_head *devices = dm_table_get_devices(t);
+        struct dm_dev_internal *dd = NULL;
+        struct gendisk *prev_disk = NULL, *template_disk = NULL;
+
+        list_for_each_entry(dd, devices, list) {
+                template_disk = dd->dm_dev.bdev->bd_disk;
+                if (!blk_get_integrity(template_disk))
+                        goto no_integrity;
+                if (!match_all && !blk_integrity_is_initialized(template_disk))
+                        continue; /* skip uninitialized profiles */
+                else if (prev_disk &&
+                         blk_integrity_compare(prev_disk, template_disk) < 0)
+                        goto no_integrity;
+                prev_disk = template_disk;
+        }
+
+        return template_disk;
+
+no_integrity:
+        if (prev_disk)
+                DMWARN("%s: integrity not set: %s and %s profile mismatch",
+                       dm_device_name(t->md),
+                       prev_disk->disk_name,
+                       template_disk->disk_name);
+        return NULL;
+}
+
+/*
  * Register the mapped device for blk_integrity support if
- * the underlying devices support it.
+ * the underlying devices have an integrity profile.  But all devices
+ * may not have matching profiles (checking all devices isn't reliable
+ * during table load because this table may use other DM device(s) which
+ * must be resumed before they will have an initialized integity profile).
+ * Stacked DM devices force a 2 stage integrity profile validation:
+ * 1 - during load, validate all initialized integrity profiles match
+ * 2 - during resume, validate all integrity profiles match
  */
 static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
 {
-        struct list_head *devices = dm_table_get_devices(t);
-        struct dm_dev_internal *dd;
+        struct gendisk *template_disk = NULL;
+
+        template_disk = dm_table_get_integrity_disk(t, false);
+        if (!template_disk)
+                return 0;
 
-        list_for_each_entry(dd, devices, list)
-                if (bdev_get_integrity(dd->dm_dev.bdev))
-                        return blk_integrity_register(dm_disk(md), NULL);
+        if (!blk_integrity_is_initialized(dm_disk(md))) {
+                t->integrity_supported = 1;
+                return blk_integrity_register(dm_disk(md), NULL);
+        }
 
+        /*
+         * If DM device already has an initalized integrity
+         * profile the new profile should not conflict.
+         */
+        if (blk_integrity_is_initialized(template_disk) &&
+            blk_integrity_compare(dm_disk(md), template_disk) < 0) {
+                DMWARN("%s: conflict with existing integrity profile: "
+                       "%s profile mismatch",
+                       dm_device_name(t->md),
+                       template_disk->disk_name);
+                return 1;
+        }
+
+        /* Preserve existing initialized integrity profile */
+        t->integrity_supported = 1;
         return 0;
 }
 
@@ -1091,41 +1171,27 @@ combine_limits:
 
 /*
  * Set the integrity profile for this device if all devices used have
- * matching profiles.
+ * matching profiles.  We're quite deep in the resume path but still
+ * don't know if all devices (particularly DM devices this device
+ * may be stacked on) have matching profiles.  Even if the profiles
+ * don't match we have no way to fail (to resume) at this point.
  */
 static void dm_table_set_integrity(struct dm_table *t)
 {
-        struct list_head *devices = dm_table_get_devices(t);
-        struct dm_dev_internal *prev = NULL, *dd = NULL;
+        struct gendisk *template_disk = NULL;
 
         if (!blk_get_integrity(dm_disk(t->md)))
                 return;
 
-        list_for_each_entry(dd, devices, list) {
-                if (prev &&
-                    blk_integrity_compare(prev->dm_dev.bdev->bd_disk,
-                                          dd->dm_dev.bdev->bd_disk) < 0) {
-                        DMWARN("%s: integrity not set: %s and %s mismatch",
-                               dm_device_name(t->md),
-                               prev->dm_dev.bdev->bd_disk->disk_name,
-                               dd->dm_dev.bdev->bd_disk->disk_name);
-                        goto no_integrity;
-                }
-                prev = dd;
+        template_disk = dm_table_get_integrity_disk(t, true);
+        if (!template_disk &&
+            blk_integrity_is_initialized(dm_disk(t->md))) {
+                DMWARN("%s: device no longer has a valid integrity profile",
+                       dm_device_name(t->md));
+                return;
         }
-
-        if (!prev || !bdev_get_integrity(prev->dm_dev.bdev))
-                goto no_integrity;
-
         blk_integrity_register(dm_disk(t->md),
-                               bdev_get_integrity(prev->dm_dev.bdev));
-
-        return;
-
-no_integrity:
-        blk_integrity_register(dm_disk(t->md), NULL);
-
-        return;
+                               blk_get_integrity(template_disk));
 }
 
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
@@ -1136,11 +1202,6 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
          */
         q->limits = *limits;
 
-        if (limits->no_cluster)
-                queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
-        else
-                queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
-
         if (!dm_table_supports_discards(t))
                 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
         else
@@ -1234,10 +1295,17 @@ int dm_table_resume_targets(struct dm_table *t)
         return 0;
 }
 
+void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
+{
+        list_add(&cb->list, &t->target_callbacks);
+}
+EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
+
 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 {
         struct dm_dev_internal *dd;
         struct list_head *devices = dm_table_get_devices(t);
+        struct dm_target_callbacks *cb;
         int r = 0;
 
         list_for_each_entry(dd, devices, list) {
@@ -1252,6 +1320,10 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits)
                                      bdevname(dd->dm_dev.bdev, b));
         }
 
+        list_for_each_entry(cb, &t->target_callbacks, list)
+                if (cb->congested_fn)
+                        r |= cb->congested_fn(cb, bdi_bits);
+
         return r;
 }
 
@@ -1269,24 +1341,6 @@ int dm_table_any_busy_target(struct dm_table *t)
         return 0;
 }
 
-void dm_table_unplug_all(struct dm_table *t)
-{
-        struct dm_dev_internal *dd;
-        struct list_head *devices = dm_table_get_devices(t);
-
-        list_for_each_entry(dd, devices, list) {
-                struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
-                char b[BDEVNAME_SIZE];
-
-                if (likely(q))
-                        blk_unplug(q);
-                else
-                        DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s",
-                                     dm_device_name(t->md),
-                                     bdevname(dd->dm_dev.bdev, b));
-        }
-}
-
 struct mapped_device *dm_table_get_md(struct dm_table *t)
 {
         return t->md;
@@ -1309,7 +1363,8 @@ bool dm_table_supports_discards(struct dm_table *t)
                 return 0;
 
         /*
-         * Ensure that at least one underlying device supports discards.
+         * Unless any target used by the table set discards_supported,
+         * require at least one underlying device to support discards.
          * t->devices includes internal dm devices such as mirror logs
          * so we need to use iterate_devices here, which targets
          * supporting discard must provide.
@@ -1317,6 +1372,9 @@ bool dm_table_supports_discards(struct dm_table *t)
         while (i < dm_table_get_num_targets(t)) {
                 ti = dm_table_get_target(t, i++);
 
+                if (ti->discards_supported)
+                        return 1;
+
                 if (ti->type->iterate_devices &&
                     ti->type->iterate_devices(ti, device_discard_capable, NULL))
                         return 1;
@@ -1334,4 +1392,3 @@ EXPORT_SYMBOL(dm_table_get_mode);
 EXPORT_SYMBOL(dm_table_get_md);
 EXPORT_SYMBOL(dm_table_put);
 EXPORT_SYMBOL(dm_table_get);
-EXPORT_SYMBOL(dm_table_unplug_all);