From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 10 Feb 2023 14:19:11 +0000 (+0100)
Subject: 4.14-stable patches
X-Git-Tag: v6.1.12~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e6920718b5236a6a089d6226d1d93a11e360dcb;p=thirdparty%2Fkernel%2Fstable-queue.git

4.14-stable patches

added patches:
	btrfs-limit-device-extents-to-the-device-size.patch
---

diff --git a/queue-4.14/btrfs-limit-device-extents-to-the-device-size.patch b/queue-4.14/btrfs-limit-device-extents-to-the-device-size.patch
new file mode 100644
index 00000000000..19402b071ce
--- /dev/null
+++ b/queue-4.14/btrfs-limit-device-extents-to-the-device-size.patch
@@ -0,0 +1,66 @@
+From 3c538de0f2a74d50aff7278c092f88ae59cee688 Mon Sep 17 00:00:00 2001
+From: Josef Bacik <josef@toxicpanda.com>
+Date: Wed, 18 Jan 2023 16:35:13 -0500
+Subject: btrfs: limit device extents to the device size
+
+From: Josef Bacik <josef@toxicpanda.com>
+
+commit 3c538de0f2a74d50aff7278c092f88ae59cee688 upstream.
+
+There was a recent regression in btrfs/177 that started happening with
+the size class patches ("btrfs: introduce size class to block group
+allocator").  This however isn't a regression introduced by those
+patches, but rather the bug was uncovered by a change in behavior in
+these patches.  The patches triggered more chunk allocations in the
+^free-space-tree case, which uncovered a race with device shrink.
+
+The problem is we will set the device total size to the new size, and
+use this to find a hole for a device extent.  However during shrink we
+may have device extents allocated past this range, so we could
+potentially find a hole in a range past our new shrink size.  We don't
+actually limit our found extent to the device size anywhere, we assume
+that we will not find a hole past our device size.  This isn't true with
+shrink as we're relocating block groups and thus creating holes past the
+device size.
+
+Fix this by making sure we do not search past the new device size, and
+if we wander into any device extents that start after our device size
+simply break from the loop and use whatever hole we've already found.
+
+CC: stable@vger.kernel.org # 4.14+
+Signed-off-by: Josef Bacik <josef@toxicpanda.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/btrfs/volumes.c |    6 +++++-
+ 1 file changed, 5 insertions(+), 1 deletion(-)
+
+--- a/fs/btrfs/volumes.c
++++ b/fs/btrfs/volumes.c
+@@ -1397,7 +1397,7 @@ again:
+ 			goto out;
+ 	}
+ 
+-	while (1) {
++	while (search_start < search_end) {
+ 		l = path->nodes[0];
+ 		slot = path->slots[0];
+ 		if (slot >= btrfs_header_nritems(l)) {
+@@ -1420,6 +1420,9 @@ again:
+ 		if (key.type != BTRFS_DEV_EXTENT_KEY)
+ 			goto next;
+ 
++		if (key.offset > search_end)
++			break;
++
+ 		if (key.offset > search_start) {
+ 			hole_size = key.offset - search_start;
+ 
+@@ -1494,6 +1497,7 @@ next:
+ 	else
+ 		ret = 0;
+ 
++	ASSERT(max_hole_start + max_hole_size <= search_end);
+ out:
+ 	btrfs_free_path(path);
+ 	*start = max_hole_start;
diff --git a/queue-4.14/series b/queue-4.14/series
index 6b549e06b2f..556ad5475d1 100644
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -23,3 +23,4 @@ mm-swapfile-add-cond_resched-in-get_swap_pages.patch
 squashfs-fix-handling-and-sanity-checking-of-xattr_ids-count.patch
 serial-8250_dma-fix-dma-rx-completion-race.patch
 serial-8250_dma-fix-dma-rx-rearm-race.patch
+btrfs-limit-device-extents-to-the-device-size.patch