Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Qu Wenruo <quwenruo.btrfs@gmx.com>,
        Nikolay Borisov <nborisov@suse.com>,
        David Sterba <dsterba@suse.com>,
        Ben Hutchings <ben.hutchings@codethink.co.uk>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.14 032/146] btrfs: Add checker for EXTENT_CSUM
Date:   Tue,  4 Dec 2018 11:48:38 +0100
Message-Id: <20181204103728.151080174@linuxfoundation.org>
In-Reply-To: <20181204103726.750894136@linuxfoundation.org>
References: <20181204103726.750894136@linuxfoundation.org>
User-Agent: quilt/0.65
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

commit 4b865cab96fe2a30ed512cf667b354bd291b3b0a upstream.

EXTENT_CSUM checker is a relatively easy one, only needs to check:

1) Objectid
   Fixed to BTRFS_EXTENT_CSUM_OBJECTID

2) Key offset alignment
   Must be aligned to sectorsize

3) Item size alignedment
   Must be aligned to csum size

Signed-off-by: Qu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/disk-io.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ab8925b2efd1..53841d773a40 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -627,6 +627,27 @@ static int check_extent_data_item(struct btrfs_root *root,
 	return 0;
 }
 
+static int check_csum_item(struct btrfs_root *root, struct extent_buffer *leaf,
+			   struct btrfs_key *key, int slot)
+{
+	u32 sectorsize = root->fs_info->sectorsize;
+	u32 csumsize = btrfs_super_csum_size(root->fs_info->super_copy);
+
+	if (key->objectid != BTRFS_EXTENT_CSUM_OBJECTID) {
+		CORRUPT("invalid objectid for csum item", leaf, root, slot);
+		return -EUCLEAN;
+	}
+	if (!IS_ALIGNED(key->offset, sectorsize)) {
+		CORRUPT("unaligned key offset for csum item", leaf, root, slot);
+		return -EUCLEAN;
+	}
+	if (!IS_ALIGNED(btrfs_item_size_nr(leaf, slot), csumsize)) {
+		CORRUPT("unaligned csum item size", leaf, root, slot);
+		return -EUCLEAN;
+	}
+	return 0;
+}
+
 /*
  * Common point to switch the item-specific validation.
  */
@@ -640,6 +661,9 @@ static int check_leaf_item(struct btrfs_root *root,
 	case BTRFS_EXTENT_DATA_KEY:
 		ret = check_extent_data_item(root, leaf, key, slot);
 		break;
+	case BTRFS_EXTENT_CSUM_KEY:
+		ret = check_csum_item(root, leaf, key, slot);
+		break;
 	}
 	return ret;
 }
-- 
2.17.1