From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 17 Nov 2016 09:45:10 +0000 (+0100)
Subject: 4.4-stable patches
X-Git-Tag: v4.4.33~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3566c5222cac046dbc24a92dfd0247de2d4d8e24;p=thirdparty%2Fkernel%2Fstable-queue.git

4.4-stable patches

added patches:
	btrfs-qgroup-prevent-qgroup-reserved-from-going-subzero.patch
---

diff --git a/queue-4.4/btrfs-qgroup-prevent-qgroup-reserved-from-going-subzero.patch b/queue-4.4/btrfs-qgroup-prevent-qgroup-reserved-from-going-subzero.patch
new file mode 100644
index 00000000000..c2a3935a772
--- /dev/null
+++ b/queue-4.4/btrfs-qgroup-prevent-qgroup-reserved-from-going-subzero.patch
@@ -0,0 +1,69 @@
+From 0b34c261e235a5c74dcf78bd305845bd15fe2b42 Mon Sep 17 00:00:00 2001
+From: Goldwyn Rodrigues <rgoldwyn@suse.com>
+Date: Fri, 30 Sep 2016 10:40:52 -0500
+Subject: btrfs: qgroup: Prevent qgroup->reserved from going subzero
+
+From: Goldwyn Rodrigues <rgoldwyn@suse.com>
+
+commit 0b34c261e235a5c74dcf78bd305845bd15fe2b42 upstream.
+
+While free'ing qgroup->reserved resources, we much check if
+the page has not been invalidated by a truncate operation
+by checking if the page is still dirty before reducing the
+qgroup resources. Resources in such a case are free'd when
+the entire extent is released by delayed_ref.
+
+This fixes a double accounting while releasing resources
+in case of truncating a file, reproduced by the following testcase.
+
+SCRATCH_DEV=/dev/vdb
+SCRATCH_MNT=/mnt
+mkfs.btrfs -f $SCRATCH_DEV
+mount -t btrfs $SCRATCH_DEV $SCRATCH_MNT
+cd $SCRATCH_MNT
+btrfs quota enable $SCRATCH_MNT
+btrfs subvolume create a
+btrfs qgroup limit 500m a $SCRATCH_MNT
+sync
+for c in {1..15}; do
+dd if=/dev/zero  bs=1M count=40 of=$SCRATCH_MNT/a/file;
+done
+
+sleep 10
+sync
+sleep 5
+
+touch $SCRATCH_MNT/a/newfile
+
+echo "Removing file"
+rm $SCRATCH_MNT/a/file
+
+Fixes: b9d0b38928 ("btrfs: Add handler for invalidate page")
+Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
+Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
+Signed-off-by: David Sterba <dsterba@suse.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/btrfs/inode.c |    9 +++++++--
+ 1 file changed, 7 insertions(+), 2 deletions(-)
+
+--- a/fs/btrfs/inode.c
++++ b/fs/btrfs/inode.c
+@@ -8691,9 +8691,14 @@ static void btrfs_invalidatepage(struct
+ 	 *    So even we call qgroup_free_data(), it won't decrease reserved
+ 	 *    space.
+ 	 * 2) Not written to disk
+-	 *    This means the reserved space should be freed here.
++	 *    This means the reserved space should be freed here. However,
++	 *    if a truncate invalidates the page (by clearing PageDirty)
++	 *    and the page is accounted for while allocating extent
++	 *    in btrfs_check_data_free_space() we let delayed_ref to
++	 *    free the entire extent.
+ 	 */
+-	btrfs_qgroup_free_data(inode, page_start, PAGE_CACHE_SIZE);
++	if (PageDirty(page))
++		btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
+ 	if (!inode_evicting) {
+ 		clear_extent_bit(tree, page_start, page_end,
+ 				 EXTENT_LOCKED | EXTENT_DIRTY |
diff --git a/queue-4.4/series b/queue-4.4/series
index 24239aac666..d66bdf95133 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -34,3 +34,4 @@ i40e-fix-call-of-ndo_dflt_bridge_getlink.patch
 acpi-apei-fix-incorrect-return-value-of-ghes_proc.patch
 asoc-sun4i-codec-return-error-code-instead-of-null-when-create_card-fails.patch
 mmc-mxs-initialize-the-spinlock-prior-to-using-it.patch
+btrfs-qgroup-prevent-qgroup-reserved-from-going-subzero.patch