Patch "btrfs: make state preallocation more speculative in __set_extent_bit" has been added to the 4.5-stable tree

This is a note to let you know that I've just added the patch titled

    btrfs: make state preallocation more speculative in __set_extent_bit

to the 4.5-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     btrfs-make-state-preallocation-more-speculative-in-__set_extent_bit.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.

From 059f791c6bbaba72dc3c1bd6e2657aacc8552849 Mon Sep 17 00:00:00 2001

From: David Sterba <dsterba@suse.com>
Date: Wed, 27 Apr 2016 01:03:45 +0200
Subject: btrfs: make state preallocation more speculative in __set_extent_bit

From: David Sterba <dsterba@suse.com>

commit 059f791c6bbaba72dc3c1bd6e2657aacc8552849 upstream.

Similar to __clear_extent_bit, do not fail if the state preallocation
fails as we might not need it. One less BUG_ON.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/btrfs/extent_io.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c

@@ -875,8 +875,14 @@ __set_extent_bit(struct extent_io_tree *
 	bits |= EXTENT_FIRST_DELALLOC;
 again:
 	if (!prealloc && gfpflags_allow_blocking(mask)) {
+		/*
+		 * Don't care for allocation failure here because we might end
+		 * up not needing the pre-allocated extent state at all, which
+		 * is the case if we only have in the tree extent states that
+		 * cover our input range and don't cover too any other range.
+		 * If we end up needing a new extent state we allocate it later.
+		 */
 		prealloc = alloc_extent_state(mask);
-		BUG_ON(!prealloc);
 	}
 
 	spin_lock(&tree->lock);

Patches currently in stable-queue which might be from dsterba@suse.com are

queue-4.5/btrfs-bugfix-handle-fs_ioc32_-getflags-setflags-getversion-in-btrfs_ioctl.patch
queue-4.5/btrfs-pass-the-right-error-code-to-the-btrfs_std_error.patch
queue-4.5/btrfs-fix-mixed-block-count-of-available-space.patch
queue-4.5/btrfs-fix-memory-leak-during-raid-5-6-device-replacement.patch
queue-4.5/btrfs-fix-unexpected-return-value-of-fiemap.patch
queue-4.5/btrfs-do-not-create-empty-block-group-if-we-have-allocated-data.patch
queue-4.5/btrfs-add-check-to-sysfs-handler-of-label.patch
queue-4.5/btrfs-avoid-overflowing-f_bfree.patch
queue-4.5/btrfs-fix-int32-overflow-in-shrink_delalloc.patch
queue-4.5/btrfs-remove-bug_on-s-in-btrfs_map_block.patch
queue-4.5/btrfs-make-state-preallocation-more-speculative-in-__set_extent_bit.patch
queue-4.5/btrfs-fix-fspath-error-deallocation.patch
queue-4.5/btrfs-scrub-set-bbio-to-null-before-calling-btrfs_map_block.patch
queue-4.5/btrfs-add-write-protection-to-set_features-ioctl.patch
queue-4.5/btrfs-allow-balancing-to-dup-with-multi-device.patch
queue-4.5/btrfs-fix-divide-error-upon-chunk-s-stripe_len.patch
queue-4.5/btrfs-fix-lock-dep-warning-move-scratch-dev-out-of-device_list_mutex-and-uuid_mutex.patch