4.4-stable patches

added patches:
	workqueue-implicit-ordered-attribute-should-be-overridable.patch

diff --git a/queue-4.4/series b/queue-4.4/series
index e3b0dfc0f0a19ef6b0aa5f5a737a9a7f4b2d294d..1daaf77008fb6b4cb3dc2799606ed14843b069bd 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -56,3 +56,4 @@ signal-protect-signal_unkillable-from-unintentional-clearing.patch
 mm-don-t-dereference-struct-page-fields-of-invalid-pages.patch
 ipv4-should-use-consistent-conditional-judgement-for-ip-fragment-in-__ip_append_data-and-ip_finish_output.patch
 net-account-for-current-skb-length-when-deciding-about-ufo.patch
+workqueue-implicit-ordered-attribute-should-be-overridable.patch

diff --git a/queue-4.4/workqueue-implicit-ordered-attribute-should-be-overridable.patch b/queue-4.4/workqueue-implicit-ordered-attribute-should-be-overridable.patch
new file mode 100644 (file)
index 0000000..5a2a0f5
--- /dev/null
+++ b/queue-4.4/workqueue-implicit-ordered-attribute-should-be-overridable.patch
@@ -0,0 +1,91 @@
+From 0a94efb5acbb6980d7c9ab604372d93cd507e4d8 Mon Sep 17 00:00:00 2001
+From: Tejun Heo <tj@kernel.org>
+Date: Sun, 23 Jul 2017 08:36:15 -0400
+Subject: workqueue: implicit ordered attribute should be overridable
+
+From: Tejun Heo <tj@kernel.org>
+
+commit 0a94efb5acbb6980d7c9ab604372d93cd507e4d8 upstream.
+
+5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be
+ordered") automatically enabled ordered attribute for unbound
+workqueues w/ max_active == 1.  Because ordered workqueues reject
+max_active and some attribute changes, this implicit ordered mode
+broke cases where the user creates an unbound workqueue w/ max_active
+== 1 and later explicitly changes the related attributes.
+
+This patch distinguishes explicit and implicit ordered setting and
+overrides from attribute changes if implict.
+
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Fixes: 5c0338c68706 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
+Cc: Holger Hoffstätte <holger@applied-asynchrony.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ include/linux/workqueue.h |    4 +++-
+ kernel/workqueue.c        |   13 +++++++++----
+ 2 files changed, 12 insertions(+), 5 deletions(-)
+
+--- a/include/linux/workqueue.h
++++ b/include/linux/workqueue.h
+@@ -311,6 +311,7 @@ enum {
+ 
+       __WQ_DRAINING           = 1 << 16, /* internal: workqueue is draining */
+       __WQ_ORDERED            = 1 << 17, /* internal: workqueue is ordered */
++      __WQ_ORDERED_EXPLICIT   = 1 << 18, /* internal: alloc_ordered_workqueue() */
+ 
+       WQ_MAX_ACTIVE           = 512,    /* I like 512, better ideas? */
+       WQ_MAX_UNBOUND_PER_CPU  = 4,      /* 4 * #cpus for unbound wq */
+@@ -408,7 +409,8 @@ __alloc_workqueue_key(const char *fmt, u
+  * Pointer to the allocated workqueue on success, %NULL on failure.
+  */
+ #define alloc_ordered_workqueue(fmt, flags, args...)                  \
+-      alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args)
++      alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED |                \
++                      __WQ_ORDERED_EXPLICIT | (flags), 1, ##args)
+ 
+ #define create_workqueue(name)                                                \
+       alloc_workqueue("%s", WQ_MEM_RECLAIM, 1, (name))
+--- a/kernel/workqueue.c
++++ b/kernel/workqueue.c
+@@ -3647,8 +3647,12 @@ static int apply_workqueue_attrs_locked(
+               return -EINVAL;
+ 
+       /* creating multiple pwqs breaks ordering guarantee */
+-      if (WARN_ON((wq->flags & __WQ_ORDERED) && !list_empty(&wq->pwqs)))
+-              return -EINVAL;
++      if (!list_empty(&wq->pwqs)) {
++              if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
++                      return -EINVAL;
++
++              wq->flags &= ~__WQ_ORDERED;
++      }
+ 
+       ctx = apply_wqattrs_prepare(wq, attrs);
+ 
+@@ -4032,13 +4036,14 @@ void workqueue_set_max_active(struct wor
+       struct pool_workqueue *pwq;
+ 
+       /* disallow meddling with max_active for ordered workqueues */
+-      if (WARN_ON(wq->flags & __WQ_ORDERED))
++      if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
+               return;
+ 
+       max_active = wq_clamp_max_active(max_active, wq->flags, wq->name);
+ 
+       mutex_lock(&wq->mutex);
+ 
++      wq->flags &= ~__WQ_ORDERED;
+       wq->saved_max_active = max_active;
+ 
+       for_each_pwq(pwq, wq)
+@@ -5164,7 +5169,7 @@ int workqueue_sysfs_register(struct work
+        * attributes breaks ordering guarantee.  Disallow exposing ordered
+        * workqueues.
+        */
+-      if (WARN_ON(wq->flags & __WQ_ORDERED))
++      if (WARN_ON(wq->flags & __WQ_ORDERED_EXPLICIT))
+               return -EINVAL;
+ 
+       wq->wq_dev = wq_dev = kzalloc(sizeof(*wq_dev), GFP_KERNEL);