Merge branch 'queue' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending

Pull target fixes from Nicholas Bellinger:
 "A handful of fixes + minor changes this time around, along with one
  important >= v3.9 regression fix for IBLOCK backends.  The highlights
  include:

   - Use FD_MAX_SECTORS in FILEIO for block_device as
     well as files (agrover)

   - Fix processing of out-of-order CmdSNs with
     iSBD driver (shlomo)

   - Close long-standing target_put_sess_cmd() vs.
     core_tmr_abort_task() race with the addition of
     kref_put_spinlock_irqsave() (joern + greg-kh)

   - Fix IBLOCK WCE=1 + DPOFUA=1 backend WRITE
     regression in >= v3.9 (nab + bootc)

  Note these four patches are CC'ed to stable.

  Also, there is still some work left to be done on the active I/O
  shutdown path in target_wait_for_sess_cmds() used by tcm_qla2xxx +
  ib_isert fabrics that is still being discussed on the list, and will
  hopefully be resolved soon."

* 'queue' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: close target_put_sess_cmd() vs. core_tmr_abort_task() race
  target: removed unused transport_state flag
  target/iblock: Fix WCE=1 + DPOFUA=1 backend WRITE regression
  MAINTAINERS: Update target git tree URL
  iscsi-target: Fix typos in RDMAEXTENSIONS macro usage
  target/rd: Add ramdisk bit for NULLIO operation
  iscsi-target: Fix processing of OOO commands
  iscsi-target: Make buf param of iscsit_do_crypto_hash_buf() const void *
  iscsi-target: Fix NULL pointer dereference in iscsit_send_reject
  target: Have dev/enable show if TCM device is configured
  target: Use FD_MAX_SECTORS/FD_BLOCKSIZE for blockdevs using fileio
  target: Remove unused struct members in se_dev_entry

1 files changed, 33 insertions, 0 deletions

diff --git a/include/linux/kref.h b/include/linux/kref.h
index e15828fd71f1..484604d184be 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -19,6 +19,7 @@
 #include <linux/atomic.h>
 #include <linux/kernel.h>
 #include <linux/mutex.h>
+#include <linux/spinlock.h>
 
 struct kref {
 	atomic_t refcount;
@@ -98,6 +99,38 @@ static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref)
 	return kref_sub(kref, 1, release);
 }
 
+/**
+ * kref_put_spinlock_irqsave - decrement refcount for object.
+ * @kref: object.
+ * @release: pointer to the function that will clean up the object when the
+ *	     last reference to the object is released.
+ *	     This pointer is required, and it is not acceptable to pass kfree
+ *	     in as this function.
+ * @lock: lock to take in release case
+ *
+ * Behaves identical to kref_put with one exception.  If the reference count
+ * drops to zero, the lock will be taken atomically wrt dropping the reference
+ * count.  The release function has to call spin_unlock() without _irqrestore.
+ */
+static inline int kref_put_spinlock_irqsave(struct kref *kref,
+		void (*release)(struct kref *kref),
+		spinlock_t *lock)
+{
+	unsigned long flags;
+
+	WARN_ON(release == NULL);
+	if (atomic_add_unless(&kref->refcount, -1, 1))
+		return 0;
+	spin_lock_irqsave(lock, flags);
+	if (atomic_dec_and_test(&kref->refcount)) {
+		release(kref);
+		local_irq_restore(flags);
+		return 1;
+	}
+	spin_unlock_irqrestore(lock, flags);
+	return 0;
+}
+
 static inline int kref_put_mutex(struct kref *kref,
 				 void (*release)(struct kref *kref),
 				 struct mutex *lock)