Merge branch 'for-4.5/drivers' of git://git.kernel.dk/linux-block

Pull block driver updates from Jens Axboe:
 "This is the block driver pull request for 4.5, with the exception of
  NVMe, which is in a separate branch and will be posted after this one.

  This pull request contains:

   - A set of bcache stability fixes, which have been acked by Kent.
     These have been used and tested for more than a year by the
     community, so it's about time that they got in.

   - A set of drbd updates from the drbd team (Andreas, Lars, Philipp)
     and Markus Elfring, Oleg Drokin.

   - A set of fixes for xen blkback/front from the usual suspects, (Bob,
     Konrad) as well as community based fixes from Kiri, Julien, and
     Peng.

   - A 2038 time fix for sx8 from Shraddha, with a fix from me.

   - A small mtip32xx cleanup from Zhu Yanjun.

   - A null_blk division fix from Arnd"

* 'for-4.5/drivers' of git://git.kernel.dk/linux-block: (71 commits)
  null_blk: use sector_div instead of do_div
  mtip32xx: restrict variables visible in current code module
  xen/blkfront: Fix crash if backend doesn't follow the right states.
  xen/blkback: Fix two memory leaks.
  xen/blkback: make st_ statistics per ring
  xen/blkfront: Handle non-indirect grant with 64KB pages
  xen-blkfront: Introduce blkif_ring_get_request
  xen-blkback: clear PF_NOFREEZE for xen_blkif_schedule()
  xen/blkback: Free resources if connect_ring failed.
  xen/blocks: Return -EXX instead of -1
  xen/blkback: make pool of persistent grants and free pages per-queue
  xen/blkback: get the number of hardware queues/rings from blkfront
  xen/blkback: pseudo support for multi hardware queues/rings
  xen/blkback: separate ring information out of struct xen_blkif
  xen/blkfront: correct setting for xen_blkif_max_ring_order
  xen/blkfront: make persistent grants pool per-queue
  xen/blkfront: Remove duplicate setting of ->xbdev.
  xen/blkfront: Cleanup of comments, fix unaligned variables, and syntax errors.
  xen/blkfront: negotiate number of queues/rings to be used with backend
  xen/blkfront: split per device io_lock
  ...

4 files changed, 48 insertions, 13 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index 83392f856dfd..22b9e34ceb75 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1741,6 +1741,7 @@ static void bch_btree_gc(struct cache_set *c)
         do {
                 ret = btree_root(gc_root, c, &op, &writes, &stats);
                 closure_sync(&writes);
+                cond_resched();
 
                 if (ret && ret != -EAGAIN)
                         pr_warn("gc failed!");
@@ -2162,8 +2163,10 @@ int bch_btree_insert_check_key(struct btree *b, struct btree_op *op,
                 rw_lock(true, b, b->level);
 
                 if (b->key.ptr[0] != btree_ptr ||
-                    b->seq != seq + 1)
+                   b->seq != seq + 1) {
+                       op->lock = b->level;
                         goto out;
+               }
         }
 
         SET_KEY_PTRS(check_key, 1);
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 679a093a3bf6..8d0ead98eb6e 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -685,6 +685,8 @@ static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
         WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
              sysfs_create_link(&c->kobj, &d->kobj, d->name),
              "Couldn't create device <-> cache set symlinks");
+
+        clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
 }
 
 static void bcache_device_detach(struct bcache_device *d)
@@ -847,8 +849,11 @@ void bch_cached_dev_run(struct cached_dev *dc)
         buf[SB_LABEL_SIZE] = '\0';
         env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf);
 
-        if (atomic_xchg(&dc->running, 1))
+        if (atomic_xchg(&dc->running, 1)) {
+                kfree(env[1]);
+                kfree(env[2]);
                 return;
+        }
 
         if (!d->c &&
             BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
@@ -1933,6 +1938,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
                         else
                                 err = "device busy";
                         mutex_unlock(&bch_register_lock);
+                        if (attr == &ksysfs_register_quiet)
+                                goto out;
                 }
                 goto err;
         }
@@ -1971,8 +1978,7 @@ out:
 err_close:
         blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 err:
-        if (attr != &ksysfs_register_quiet)
-                pr_info("error opening %s: %s", path, err);
+        pr_info("error opening %s: %s", path, err);
         ret = -EINVAL;
         goto out;
 }
@@ -2066,8 +2072,10 @@ static int __init bcache_init(void)
         closure_debug_init();
 
         bcache_major = register_blkdev(0, "bcache");
-        if (bcache_major < 0)
+        if (bcache_major < 0) {
+                unregister_reboot_notifier(&reboot);
                 return bcache_major;
+        }
 
         if (!(bcache_wq = create_workqueue("bcache")) ||
             !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index b23f88d9f18c..b9346cd9cda1 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -323,6 +323,10 @@ void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode,
 
 static bool dirty_pred(struct keybuf *buf, struct bkey *k)
 {
+        struct cached_dev *dc = container_of(buf, struct cached_dev, writeback_keys);
+
+        BUG_ON(KEY_INODE(k) != dc->disk.id);
+
         return KEY_DIRTY(k);
 }
 
@@ -372,11 +376,24 @@ next:
         }
 }
 
+/*
+ * Returns true if we scanned the entire disk
+ */
 static bool refill_dirty(struct cached_dev *dc)
 {
         struct keybuf *buf = &dc->writeback_keys;
+        struct bkey start = KEY(dc->disk.id, 0, 0);
         struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0);
-        bool searched_from_start = false;
+        struct bkey start_pos;
+
+        /*
+         * make sure keybuf pos is inside the range for this disk - at bringup
+         * we might not be attached yet so this disk's inode nr isn't
+         * initialized then
+         */
+        if (bkey_cmp(&buf->last_scanned, &start) < 0 ||
+            bkey_cmp(&buf->last_scanned, &end) > 0)
+                buf->last_scanned = start;
 
         if (dc->partial_stripes_expensive) {
                 refill_full_stripes(dc);
@@ -384,14 +401,20 @@ static bool refill_dirty(struct cached_dev *dc)
                         return false;
         }
 
-        if (bkey_cmp(&buf->last_scanned, &end) >= 0) {
-                buf->last_scanned = KEY(dc->disk.id, 0, 0);
-                searched_from_start = true;
-        }
-
+        start_pos = buf->last_scanned;
         bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred);
 
-        return bkey_cmp(&buf->last_scanned, &end) >= 0 && searched_from_start;
+        if (bkey_cmp(&buf->last_scanned, &end) < 0)
+                return false;
+
+        /*
+         * If we get to the end start scanning again from the beginning, and
+         * only scan up to where we initially started scanning from:
+         */
+        buf->last_scanned = start;
+        bch_refill_keybuf(dc->disk.c, buf, &start_pos, dirty_pred);
+
+        return bkey_cmp(&buf->last_scanned, &start_pos) >= 0;
 }
 
 static int bch_writeback_thread(void *arg)
diff --git a/drivers/md/bcache/writeback.h b/drivers/md/bcache/writeback.h
index 0a9dab187b79..073a042aed24 100644
--- a/drivers/md/bcache/writeback.h
+++ b/drivers/md/bcache/writeback.h
@@ -63,7 +63,8 @@ static inline bool should_writeback(struct cached_dev *dc, struct bio *bio,
 
 static inline void bch_writeback_queue(struct cached_dev *dc)
 {
-        wake_up_process(dc->writeback_thread);
+        if (!IS_ERR_OR_NULL(dc->writeback_thread))
+                wake_up_process(dc->writeback_thread);
 }
 
 static inline void bch_writeback_add(struct cached_dev *dc)