Merge tag 'dm-3.13-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:
 "A set of device-mapper changes for 3.13.

  Improve reliability of buffer allocations for dm messages with a small
  number of arguments, a couple path group initialization fixes for dm
  multipath, a fix for resizing a dm array, various fixes and
  optimizations for dm cache, a fix for device mapper's Kconfig menu
  indentation.

  Features added include:
   - dm crypt support for activating legacy CBC TrueCrypt containers
     (useful for forensics of these old TCRYPT containers)
   - reduced dm-cache memory requirements for each block in the cache
   - basic support for shrinking a dm-cache's cache (fast) device
   - most notably, dm-cache support for managing cache coherency when
     deploying dm-cache with sophisticated origin volumes (that support
     hardware snapshots and/or clustering): these changes come in the
     form of a new passthrough operation mode and a cache block
     invalidation interface"

* tag 'dm-3.13-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (32 commits)
  dm cache: resolve small nits and improve Documentation
  dm cache: add cache block invalidation support
  dm cache: add remove_cblock method to policy interface
  dm cache policy mq: reduce memory requirements
  dm cache metadata: check the metadata version when reading the superblock
  dm cache: add passthrough mode
  dm cache: cache shrinking support
  dm cache: promotion optimisation for writes
  dm cache: be much more aggressive about promoting writes to discarded blocks
  dm cache policy mq: implement writeback_work() and mq_{set,clear}_dirty()
  dm cache: optimize commit_if_needed
  dm space map disk: optimise sm_disk_dec_block
  MAINTAINERS: add reference to device-mapper's linux-dm.git tree
  dm: fix Kconfig menu indentation
  dm: allow remove to be deferred
  dm table: print error on preresume failure
  dm crypt: add TCW IV mode for old CBC TCRYPT containers
  dm crypt: properly handle extra key string in initialization
  dm cache: log error message if dm_kcopyd_copy() fails
  dm cache: use cell_defer() boolean argument consistently
  ...

1 files changed, 27 insertions, 7 deletions

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index de570a55876..6eb9dc9ef8f 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -87,6 +87,7 @@ struct multipath {
 	unsigned queue_if_no_path:1;	/* Queue I/O if last path fails? */
 	unsigned saved_queue_if_no_path:1; /* Saved state during suspension */
 	unsigned retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */
+	unsigned pg_init_disabled:1;	/* pg_init is not currently allowed */
 
 	unsigned pg_init_retries;	/* Number of times to retry pg_init */
 	unsigned pg_init_count;		/* Number of times pg_init called */
@@ -390,13 +391,16 @@ static int map_io(struct multipath *m, struct request *clone,
 	if (was_queued)
 		m->queue_size--;
 
-	if ((pgpath && m->queue_io) ||
-	    (!pgpath && m->queue_if_no_path)) {
+	if (m->pg_init_required) {
+		if (!m->pg_init_in_progress)
+			queue_work(kmultipathd, &m->process_queued_ios);
+		r = DM_MAPIO_REQUEUE;
+	} else if ((pgpath && m->queue_io) ||
+		   (!pgpath && m->queue_if_no_path)) {
 		/* Queue for the daemon to resubmit */
 		list_add_tail(&clone->queuelist, &m->queued_ios);
 		m->queue_size++;
-		if ((m->pg_init_required && !m->pg_init_in_progress) ||
-		    !m->queue_io)
+		if (!m->queue_io)
 			queue_work(kmultipathd, &m->process_queued_ios);
 		pgpath = NULL;
 		r = DM_MAPIO_SUBMITTED;
@@ -497,7 +501,8 @@ static void process_queued_ios(struct work_struct *work)
 	    (!pgpath && !m->queue_if_no_path))
 		must_queue = 0;
 
-	if (m->pg_init_required && !m->pg_init_in_progress && pgpath)
+	if (m->pg_init_required && !m->pg_init_in_progress && pgpath &&
+	    !m->pg_init_disabled)
 		__pg_init_all_paths(m);
 
 	spin_unlock_irqrestore(&m->lock, flags);
@@ -942,10 +947,20 @@ static void multipath_wait_for_pg_init_completion(struct multipath *m)
 
 static void flush_multipath_work(struct multipath *m)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&m->lock, flags);
+	m->pg_init_disabled = 1;
+	spin_unlock_irqrestore(&m->lock, flags);
+
 	flush_workqueue(kmpath_handlerd);
 	multipath_wait_for_pg_init_completion(m);
 	flush_workqueue(kmultipathd);
 	flush_work(&m->trigger_event);
+
+	spin_lock_irqsave(&m->lock, flags);
+	m->pg_init_disabled = 0;
+	spin_unlock_irqrestore(&m->lock, flags);
 }
 
 static void multipath_dtr(struct dm_target *ti)
@@ -1164,7 +1179,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
 
 	spin_lock_irqsave(&m->lock, flags);
 
-	if (m->pg_init_count <= m->pg_init_retries)
+	if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled)
 		m->pg_init_required = 1;
 	else
 		limit_reached = 1;
@@ -1665,6 +1680,11 @@ static int multipath_busy(struct dm_target *ti)
 
 	spin_lock_irqsave(&m->lock, flags);
 
+	/* pg_init in progress, requeue until done */
+	if (m->pg_init_in_progress) {
+		busy = 1;
+		goto out;
+	}
 	/* Guess which priority_group will be used at next mapping time */
 	if (unlikely(!m->current_pgpath && m->next_pg))
 		pg = m->next_pg;
@@ -1714,7 +1734,7 @@ out:
  *---------------------------------------------------------------*/
 static struct target_type multipath_target = {
 	.name = "multipath",
-	.version = {1, 5, 1},
+	.version = {1, 6, 0},
 	.module = THIS_MODULE,
 	.ctr = multipath_ctr,
 	.dtr = multipath_dtr,