Merge tag 'v3.9-rc3' into v4l_for_linus

Linux 3.9-rc3

* tag 'v3.9-rc3': (11231 commits)
  Linux 3.9-rc3
  perf,x86: fix link failure for non-Intel configs
  perf,x86: fix wrmsr_on_cpu() warning on suspend/resume
  Btrfs: fix warning of free_extent_map
  perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
  ALSA: hda - Fix missing EAPD/GPIO setup for Cirrus codecs
  sound: sequencer: cap array index in seq_chn_common_event()
  mfd: twl4030-madc: Remove __exit_p annotation
  ALSA: hda/ca0132 - Remove extra setting of dsp_state.
  ALSA: hda/ca0132 - Check download state of DSP.
  ALSA: hda/ca0132 - Check if dspload_image succeeded.
  mm/fremap.c: fix possible oops on error path
  list: Fix double fetch of pointer in hlist_entry_safe()
  Btrfs: fix warning when creating snapshots
  Btrfs: return as soon as possible when edquot happens
  Btrfs: return EIO if we have extent tree corruption
  btrfs: use rcu_barrier() to wait for bdev puts at unmount
  Btrfs: remove btrfs_try_spin_lock
  Btrfs: get better concurrency for snapshot-aware defrag work
  hwmon: (pmbus/ltc2978) Fix temperature reporting
  ...

1 files changed, 11 insertions, 0 deletions

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index d3ca2b3ee176..41733c5dc820 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -221,12 +221,23 @@ static ssize_t max_ratio_store(struct device *dev,
 }
 BDI_SHOW(max_ratio, bdi->max_ratio)
 
+static ssize_t stable_pages_required_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *page)
+{
+	struct backing_dev_info *bdi = dev_get_drvdata(dev);
+
+	return snprintf(page, PAGE_SIZE-1, "%d\n",
+			bdi_cap_stable_pages_required(bdi) ? 1 : 0);
+}
+
 #define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
 
 static struct device_attribute bdi_dev_attrs[] = {
 	__ATTR_RW(read_ahead_kb),
 	__ATTR_RW(min_ratio),
 	__ATTR_RW(max_ratio),
+	__ATTR_RO(stable_pages_required),
 	__ATTR_NULL,
 };