Merge tag 'isci-for-3.5' into misc

isci update for 3.5

1/ Rework remote-node-context (RNC) handling for proper management of
   the silicon state machine in error handling and hot-plug conditions.
   Further details below, suffice to say if the RNC is mismanaged the
   silicon state machines may lock up.

2/ Refactor the initialization code to be reused for suspend/resume support

3/ Miscellaneous bug fixes to address discovery issues and hardware
   compatibility.

RNC rework details from Jeff Skirvin:

In the controller, devices as they appear on a SAS domain (or
direct-attached SATA devices) are represented by memory structures known
as "Remote Node Contexts" (RNCs).  These structures are transferred from
main memory to the controller using a set of register commands; these
commands include setting up the context ("posting"), removing the
context ("invalidating"), and commands to control the scheduling of
commands and connections to that remote device ("suspensions" and
"resumptions").  There is a similar path to control RNC scheduling from
the protocol engine, which interprets the results of command and data
transmission and reception.

In general, the controller chooses among non-suspended RNCs to find one
that has work requiring scheduling the transmission of command and data
frames to a target.  Likewise, when a target tries to return data back
to the initiator, the state of the RNC is used by the controller to
determine how to treat the incoming request. As an example, if the RNC
is in the state "TX/RX Suspended", incoming SSP connection requests from
the target will be rejected by the controller hardware.  When an RNC is
"TX Suspended", it will not be selected by the controller hardware to
start outgoing command or data operations (with certain priority-based
exceptions).

As mentioned above, there are two sources for management of the RNC
states: commands from driver software, and the result of transmission
and reception conditions of commands and data signaled by the controller
hardware.  As an example of the latter, if an outgoing SSP command ends
with a OPEN_REJECT(BAD_DESTINATION) status, the RNC state will
transition to the "TX Suspended" state, and this is signaled by the
controller hardware in the status to the completion of the pending
command as well as signaled in a controller hardware event.  Examples of
the former are included in the patch changelogs.

Driver software is required to suspend the RNC in a "TX/RX Suspended"
condition before any outstanding commands can be terminated.  Failure to
guarantee this can lead to a complete hardware hang condition.  Earlier
versions of the driver software did not guarantee that an RNC was
correctly managed before I/O termination, and so operated in an unsafe
way.

Further, the driver performed unnecessary contortions to preserve the
remote device command state and so was more complicated than it needed
to be.  A simplifying driver assumption is that once an I/O has entered
the error handler path without having completed in the target, the
requirement on the driver is that all use of the sas_task must end.
Beyond that, recovery of operation is dependent on libsas and other
components to reset, rediscover and reconfigure the device before normal
operation can restart.  In the driver, this simplifying assumption meant
that the RNC management could be reduced to entry into the suspended
state, terminating the targeted I/O request, and resuming the RNC as
needed for device-specific management such as an SSP Abort Task or LUN
Reset Management request.

7 files changed, 22 insertions, 17 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 97e73e555d11..17e2b472e16d 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1727,8 +1727,7 @@ int bitmap_create(struct mddev *mddev)
 	bitmap->chunkshift = (ffz(~mddev->bitmap_info.chunksize)
 			      - BITMAP_BLOCK_SHIFT);
 
-	/* now that chunksize and chunkshift are set, we can use these macros */
-	chunks = (blocks + bitmap->chunkshift - 1) >>
+	chunks = (blocks + (1 << bitmap->chunkshift) - 1) >>
 			bitmap->chunkshift;
 	pages = (chunks + PAGE_COUNTER_RATIO - 1) / PAGE_COUNTER_RATIO;
 
diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h
index 55ca5aec84e4..b44b0aba2d47 100644
--- a/drivers/md/bitmap.h
+++ b/drivers/md/bitmap.h
@@ -101,9 +101,6 @@ typedef __u16 bitmap_counter_t;
 
 #define BITMAP_BLOCK_SHIFT 9
 
-/* how many blocks per chunk? (this is variable) */
-#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->mddev->bitmap_info.chunksize >> BITMAP_BLOCK_SHIFT)
-
 #endif
 
 /*
diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c
index 1f23e048f077..08d9a207259a 100644
--- a/drivers/md/dm-log-userspace-transfer.c
+++ b/drivers/md/dm-log-userspace-transfer.c
@@ -134,7 +134,7 @@ static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 {
 	struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1);
 
-	if (!cap_raised(current_cap(), CAP_SYS_ADMIN))
+	if (!capable(CAP_SYS_ADMIN))
 		return;
 
 	spin_lock(&receiving_list_lock);
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 922a3385eead..754f38f8a692 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -718,8 +718,8 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
 		return 0;
 
 	m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
-	request_module("scsi_dh_%s", m->hw_handler_name);
-	if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
+	if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name),
+				     "scsi_dh_%s", m->hw_handler_name)) {
 		ti->error = "unknown hardware handler type";
 		ret = -EINVAL;
 		goto fail;
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index b0ba52459ed7..68965e663248 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -859,7 +859,7 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 	int ret;
 	unsigned redundancy = 0;
 	struct raid_dev *dev;
-	struct md_rdev *rdev, *freshest;
+	struct md_rdev *rdev, *tmp, *freshest;
 	struct mddev *mddev = &rs->md;
 
 	switch (rs->raid_type->level) {
@@ -877,7 +877,7 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 	}
 
 	freshest = NULL;
-	rdev_for_each(rdev, mddev) {
+	rdev_for_each_safe(rdev, tmp, mddev) {
 		if (!rdev->meta_bdev)
 			continue;
 
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 213ae32a0fc4..2fd87b544a93 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -279,8 +279,10 @@ static void __cell_release(struct cell *cell, struct bio_list *inmates)
 
 	hlist_del(&cell->list);
 
-	bio_list_add(inmates, cell->holder);
-	bio_list_merge(inmates, &cell->bios);
+	if (inmates) {
+		bio_list_add(inmates, cell->holder);
+		bio_list_merge(inmates, &cell->bios);
+	}
 
 	mempool_free(cell, prison->cell_pool);
 }
@@ -303,9 +305,10 @@ static void cell_release(struct cell *cell, struct bio_list *bios)
  */
 static void __cell_release_singleton(struct cell *cell, struct bio *bio)
 {
-	hlist_del(&cell->list);
 	BUG_ON(cell->holder != bio);
 	BUG_ON(!bio_list_empty(&cell->bios));
+
+	__cell_release(cell, NULL);
 }
 
 static void cell_release_singleton(struct cell *cell, struct bio *bio)
@@ -1177,6 +1180,7 @@ static void no_space(struct cell *cell)
 static void process_discard(struct thin_c *tc, struct bio *bio)
 {
 	int r;
+	unsigned long flags;
 	struct pool *pool = tc->pool;
 	struct cell *cell, *cell2;
 	struct cell_key key, key2;
@@ -1218,7 +1222,9 @@ static void process_discard(struct thin_c *tc, struct bio *bio)
 			m->bio = bio;
 
 			if (!ds_add_work(&pool->all_io_ds, &m->list)) {
+				spin_lock_irqsave(&pool->lock, flags);
 				list_add(&m->list, &pool->prepared_discards);
+				spin_unlock_irqrestore(&pool->lock, flags);
 				wake_worker(pool);
 			}
 		} else {
@@ -2626,8 +2632,10 @@ static int thin_endio(struct dm_target *ti,
 	if (h->all_io_entry) {
 		INIT_LIST_HEAD(&work);
 		ds_dec(h->all_io_entry, &work);
+		spin_lock_irqsave(&pool->lock, flags);
 		list_for_each_entry_safe(m, tmp, &work, list)
 			list_add(&m->list, &pool->prepared_discards);
+		spin_unlock_irqrestore(&pool->lock, flags);
 	}
 
 	mempool_free(h, pool->endio_hook_pool);
@@ -2759,6 +2767,6 @@ static void dm_thin_exit(void)
 module_init(dm_thin_init);
 module_exit(dm_thin_exit);
 
-MODULE_DESCRIPTION(DM_NAME "device-mapper thin provisioning target");
+MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
 MODULE_AUTHOR("Joe Thornber <dm-devel@redhat.com>");
 MODULE_LICENSE("GPL");
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b572e1e386ce..477eb2e180c0 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7560,14 +7560,14 @@ void md_check_recovery(struct mddev *mddev)
 		 * any transients in the value of "sync_action".
 		 */
 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
-		clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 		/* Clear some bits that don't mean anything, but
 		 * might be left set
 		 */
 		clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
 		clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
 
-		if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
+		if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
+		    test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
 			goto unlock;
 		/* no recovery is running.
 		 * remove any failed drives, then
@@ -8140,7 +8140,8 @@ static int md_notify_reboot(struct notifier_block *this,
 
 	for_each_mddev(mddev, tmp) {
 		if (mddev_trylock(mddev)) {
-			__md_stop_writes(mddev);
+			if (mddev->pers)
+				__md_stop_writes(mddev);
 			mddev->safemode = 2;
 			mddev_unlock(mddev);
 		}