From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 29 Nov 2018 08:13:58 +0000 (+0100)
Subject: 4.19-stable patches
X-Git-Tag: v4.19.6~36
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4dc7ebfe345e4ecb247ff06935e2c13b711d4bba;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	dax-avoid-losing-wakeup-in-dax_lock_mapping_entry.patch
---

diff --git a/queue-4.19/dax-avoid-losing-wakeup-in-dax_lock_mapping_entry.patch b/queue-4.19/dax-avoid-losing-wakeup-in-dax_lock_mapping_entry.patch
new file mode 100644
index 00000000000..489c3fac7c5
--- /dev/null
+++ b/queue-4.19/dax-avoid-losing-wakeup-in-dax_lock_mapping_entry.patch
@@ -0,0 +1,45 @@
+From 25bbe21bf427a81b8e3ccd480ea0e1d940256156 Mon Sep 17 00:00:00 2001
+From: Matthew Wilcox <willy@infradead.org>
+Date: Fri, 16 Nov 2018 15:50:02 -0500
+Subject: dax: Avoid losing wakeup in dax_lock_mapping_entry
+
+From: Matthew Wilcox <willy@infradead.org>
+
+commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream.
+
+After calling get_unlocked_entry(), you have to call
+put_unlocked_entry() to avoid subsequent waiters losing wakeups.
+
+Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()")
+Cc: stable@vger.kernel.org
+Signed-off-by: Matthew Wilcox <willy@infradead.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/dax.c |    7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+--- a/fs/dax.c
++++ b/fs/dax.c
+@@ -217,6 +217,9 @@ static inline void *unlock_slot(struct a
+ 	return (void *)entry;
+ }
+ 
++static void put_unlocked_mapping_entry(struct address_space *mapping,
++				       pgoff_t index, void *entry);
++
+ /*
+  * Lookup entry in radix tree, wait for it to become unlocked if it is
+  * exceptional entry and return it. The caller must call
+@@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entr
+ 		revalidate = wait_fn();
+ 		finish_wait(wq, &ewait.wait);
+ 		xa_lock_irq(&mapping->i_pages);
+-		if (revalidate)
++		if (revalidate) {
++			put_unlocked_mapping_entry(mapping, index, entry);
+ 			return ERR_PTR(-EAGAIN);
++		}
+ 	}
+ }
+ 
diff --git a/queue-4.19/series b/queue-4.19/series
index b5ab24861f5..57906a7b759 100644
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -96,3 +96,4 @@ z3fold-fix-possible-reclaim-races.patch
 mm-memory_hotplug-check-zone_movable-in-has_unmovabl.patch
 tmpfs-make-lseek-seek_data-sek_hole-return-enxio-wit.patch
 mm-page_alloc-check-for-max-order-in-hot-path.patch
+dax-avoid-losing-wakeup-in-dax_lock_mapping_entry.patch