From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sun, 24 Nov 2013 03:27:10 +0000 (-0800)
Subject: 3.12-stable patches
X-Git-Tag: v3.11.10~51
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=379ac5f8bed936497a26375bb06c23f86bfea0ab;p=thirdparty%2Fkernel%2Fstable-queue.git

3.12-stable patches

added patches:
	xfs-be-more-forgiving-of-a-v4-secondary-sb-w-junk-in-v5-fields.patch
---

diff --git a/queue-3.12/series b/queue-3.12/series
index 628382a01e3..d2ebaf7c39e 100644
--- a/queue-3.12/series
+++ b/queue-3.12/series
@@ -1,3 +1,4 @@
 prepend_path-needs-to-reinitialize-dentry-vfsmount-mnt-on-restarts.patch
 libertas-potential-oops-in-debugfs.patch
 aacraid-prevent-invalid-pointer-dereference.patch
+xfs-be-more-forgiving-of-a-v4-secondary-sb-w-junk-in-v5-fields.patch
diff --git a/queue-3.12/xfs-be-more-forgiving-of-a-v4-secondary-sb-w-junk-in-v5-fields.patch b/queue-3.12/xfs-be-more-forgiving-of-a-v4-secondary-sb-w-junk-in-v5-fields.patch
new file mode 100644
index 00000000000..742e2f825ee
--- /dev/null
+++ b/queue-3.12/xfs-be-more-forgiving-of-a-v4-secondary-sb-w-junk-in-v5-fields.patch
@@ -0,0 +1,69 @@
+From 10e6e65dfcedff63275c3d649d329c044caa8e26 Mon Sep 17 00:00:00 2001
+From: Eric Sandeen <sandeen@sandeen.net>
+Date: Mon, 9 Sep 2013 15:33:29 -0500
+Subject: xfs: be more forgiving of a v4 secondary sb w/ junk in v5 fields
+
+From: Eric Sandeen <sandeen@sandeen.net>
+
+commit 10e6e65dfcedff63275c3d649d329c044caa8e26 upstream.
+
+Today, if xfs_sb_read_verify encounters a v4 superblock
+with junk past v4 fields which includes data in sb_crc,
+it will be treated as a failing checksum and a significant
+corruption.
+
+There are known prior bugs which leave junk at the end
+of the V4 superblock; we don't need to actually fail the
+verification in this case if other checks pan out ok.
+
+So if this is a secondary superblock, and the primary
+superblock doesn't indicate that this is a V5 filesystem,
+don't treat this as an actual checksum failure.
+
+We should probably check the garbage condition as
+we do in xfs_repair, and possibly warn about it
+or self-heal, but that's a different scope of work.
+
+Stable folks: This can go back to v3.10, which is what
+introduced the sb CRC checking that is tripped up by old,
+stale, incorrect V4 superblocks w/ unzeroed bits.
+
+Signed-off-by: Eric Sandeen <sandeen@redhat.com>
+Acked-by: Dave Chinner <david@fromorbit.com>
+Reviewed-by: Mark Tinguely <tinguely@sgi.com>
+Signed-off-by: Ben Myers <bpm@sgi.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/xfs/xfs_sb.c |   13 +++++++++++--
+ 1 file changed, 11 insertions(+), 2 deletions(-)
+
+--- a/fs/xfs/xfs_sb.c
++++ b/fs/xfs/xfs_sb.c
+@@ -596,6 +596,11 @@ xfs_sb_verify(
+  * single bit error could clear the feature bit and unused parts of the
+  * superblock are supposed to be zero. Hence a non-null crc field indicates that
+  * we've potentially lost a feature bit and we should check it anyway.
++ *
++ * However, past bugs (i.e. in growfs) left non-zeroed regions beyond the
++ * last field in V4 secondary superblocks.  So for secondary superblocks,
++ * we are more forgiving, and ignore CRC failures if the primary doesn't
++ * indicate that the fs version is V5.
+  */
+ static void
+ xfs_sb_read_verify(
+@@ -616,8 +621,12 @@ xfs_sb_read_verify(
+ 
+ 		if (!xfs_verify_cksum(bp->b_addr, be16_to_cpu(dsb->sb_sectsize),
+ 				      offsetof(struct xfs_sb, sb_crc))) {
+-			error = EFSCORRUPTED;
+-			goto out_error;
++			/* Only fail bad secondaries on a known V5 filesystem */
++			if (bp->b_bn != XFS_SB_DADDR &&
++			    xfs_sb_version_hascrc(&mp->m_sb)) {
++				error = EFSCORRUPTED;
++				goto out_error;
++			}
+ 		}
+ 	}
+ 	error = xfs_sb_verify(bp, true);