Merge tag 'dm-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Two fixes for 4.4-rc1's DM ioctl changes that introduced the potential
  for infinite recursion on ioctl (with DM multipath).

  And four stable fixes:

   - A DM thin-provisioning fix to restore 'error_if_no_space' setting
     when a thin-pool is made writable again (after having been out of
     space).

   - A DM thin-provisioning fix to properly advertise discard support
     for thin volumes that are stacked on a thin-pool whose underlying
     data device doesn't support discards.

   - A DM ioctl fix to allow ctrl-c to break out of an ioctl retry loop
     when DM multipath is configured to 'queue_if_no_path'.

   - A DM crypt fix for a possible hang on dm-crypt device removal"

* tag 'dm-4.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: fix regression in advertised discard limits
  dm crypt: fix a possible hang due to race condition on exit
  dm mpath: fix infinite recursion in ioctl when no paths and !queue_if_no_path
  dm: do not reuse dm_blk_ioctl block_device input as local variable
  dm: fix ioctl retry termination with signal
  dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition

4 files changed, 36 insertions, 29 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 917d47e290ae..3147c8d09ea8 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -112,7 +112,8 @@ struct iv_tcw_private {
  * and encrypts / decrypts at the same time.
  */
 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
-             DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
+             DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
+             DM_CRYPT_EXIT_THREAD};
 
 /*
  * The fields in here must be read only after initialization.
@@ -1203,20 +1204,18 @@ continue_locked:
                 if (!RB_EMPTY_ROOT(&cc->write_tree))
                         goto pop_from_list;
 
+                if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) {
+                        spin_unlock_irq(&cc->write_thread_wait.lock);
+                        break;
+                }
+
                 __set_current_state(TASK_INTERRUPTIBLE);
                 __add_wait_queue(&cc->write_thread_wait, &wait);
 
                 spin_unlock_irq(&cc->write_thread_wait.lock);
 
-                if (unlikely(kthread_should_stop())) {
-                        set_task_state(current, TASK_RUNNING);
-                        remove_wait_queue(&cc->write_thread_wait, &wait);
-                        break;
-                }
-
                 schedule();
 
-                set_task_state(current, TASK_RUNNING);
                 spin_lock_irq(&cc->write_thread_wait.lock);
                 __remove_wait_queue(&cc->write_thread_wait, &wait);
                 goto continue_locked;
@@ -1531,8 +1530,13 @@ static void crypt_dtr(struct dm_target *ti)
         if (!cc)
                 return;
 
-        if (cc->write_thread)
+        if (cc->write_thread) {
+                spin_lock_irq(&cc->write_thread_wait.lock);
+                set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags);
+                wake_up_locked(&cc->write_thread_wait);
+                spin_unlock_irq(&cc->write_thread_wait.lock);
                 kthread_stop(cc->write_thread);
+        }
 
         if (cc->io_queue)
                 destroy_workqueue(cc->io_queue);
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index aaa6caa46a9f..cfa29f574c2a 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1537,32 +1537,34 @@ static int multipath_prepare_ioctl(struct dm_target *ti,
                 struct block_device **bdev, fmode_t *mode)
 {
         struct multipath *m = ti->private;
-        struct pgpath *pgpath;
         unsigned long flags;
         int r;
 
-        r = 0;
-
         spin_lock_irqsave(&m->lock, flags);
 
         if (!m->current_pgpath)
                 __choose_pgpath(m, 0);
 
-        pgpath = m->current_pgpath;
-
-        if (pgpath) {
-                *bdev = pgpath->path.dev->bdev;
-                *mode = pgpath->path.dev->mode;
+        if (m->current_pgpath) {
+                if (!m->queue_io) {
+                        *bdev = m->current_pgpath->path.dev->bdev;
+                        *mode = m->current_pgpath->path.dev->mode;
+                        r = 0;
+                } else {
+                        /* pg_init has not started or completed */
+                        r = -ENOTCONN;
+                }
+        } else {
+                /* No path is available */
+                if (m->queue_if_no_path)
+                        r = -ENOTCONN;
+                else
+                        r = -EIO;
         }
 
-        if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path))
-                r = -ENOTCONN;
-        else if (!*bdev)
-                r = -EIO;
-
         spin_unlock_irqrestore(&m->lock, flags);
 
-        if (r == -ENOTCONN && !fatal_signal_pending(current)) {
+        if (r == -ENOTCONN) {
                 spin_lock_irqsave(&m->lock, flags);
                 if (!m->current_pg) {
                         /* Path status changed, redo selection */
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 3897b90bd462..63903a5a5d9e 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2432,6 +2432,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
         case PM_WRITE:
                 if (old_mode != new_mode)
                         notify_of_pool_mode_change(pool, "write");
+                pool->pf.error_if_no_space = pt->requested_pf.error_if_no_space;
                 dm_pool_metadata_read_write(pool->pmd);
                 pool->process_bio = process_bio;
                 pool->process_discard = process_discard_bio;
@@ -4249,10 +4250,9 @@ static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
         struct thin_c *tc = ti->private;
         struct pool *pool = tc->pool;
-        struct queue_limits *pool_limits = dm_get_queue_limits(pool->pool_md);
 
-        if (!pool_limits->discard_granularity)
-                return; /* pool's discard support is disabled */
+        if (!pool->pf.discard_enabled)
+                return;
 
         limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
         limits->max_discard_sectors = 2048 * 1024 * 16; /* 16G */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 6e15f3565892..5df40480228b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -591,7 +591,7 @@ retry:
 
 out:
         dm_put_live_table(md, *srcu_idx);
-        if (r == -ENOTCONN) {
+        if (r == -ENOTCONN && !fatal_signal_pending(current)) {
                 msleep(10);
                 goto retry;
         }
@@ -603,9 +603,10 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
 {
         struct mapped_device *md = bdev->bd_disk->private_data;
         struct dm_target *tgt;
+        struct block_device *tgt_bdev = NULL;
         int srcu_idx, r;
 
-        r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
+        r = dm_get_live_table_for_ioctl(md, &tgt, &tgt_bdev, &mode, &srcu_idx);
         if (r < 0)
                 return r;
 
@@ -620,7 +621,7 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
                         goto out;
         }
 
-        r =  __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+        r =  __blkdev_driver_ioctl(tgt_bdev, mode, cmd, arg);
 out:
         dm_put_live_table(md, srcu_idx);
         return r;