xfs: check that rtblock extents do not overlap with the rt group metadata

The ondisk format specifies that the start of each realtime group must
have a superblock so that rt space mappings never cross an rtgroup
boundary.  Check that rt block pointers obey this.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

1 files changed, 44 insertions, 2 deletions

diff --git a/fs/xfs/libxfs/xfs_types.c b/fs/xfs/libxfs/xfs_types.c
index b1fa715e5f39..34d02b2bfdd1 100644
--- a/fs/xfs/libxfs/xfs_types.c
+++ b/fs/xfs/libxfs/xfs_types.c
@@ -13,6 +13,8 @@
 #include "xfs_mount.h"
 #include "xfs_ag.h"
 #include "xfs_imeta.h"
+#include "xfs_rtbitmap.h"
+#include "xfs_rtgroup.h"
 
 
 /*
@@ -134,6 +136,26 @@ xfs_verify_dir_ino(
 }
 
 /*
+ * Verify that an rtgroup block number pointer neither points outside the
+ * rtgroup nor points at static metadata.
+ */
+static inline bool
+xfs_verify_rgno_rgbno(
+	struct xfs_mount	*mp,
+	xfs_rgnumber_t		rgno,
+	xfs_rgblock_t		rgbno)
+{
+	xfs_rgblock_t		eorg;
+
+	eorg = xfs_rtgroup_block_count(mp, rgno);
+	if (rgbno >= eorg)
+		return false;
+	if (rgbno < mp->m_sb.sb_rextsize)
+		return false;
+	return true;
+}
+
+/*
  * Verify that an realtime block number pointer doesn't point off the
  * end of the realtime device.
  */
@@ -142,7 +164,20 @@ xfs_verify_rtbno(
 	struct xfs_mount	*mp,
 	xfs_rtblock_t		rtbno)
 {
-	return rtbno < mp->m_sb.sb_rblocks;
+	xfs_rgnumber_t		rgno;
+	xfs_rgblock_t		rgbno;
+
+	if (rtbno >= mp->m_sb.sb_rblocks)
+		return false;
+
+	if (!xfs_has_rtgroups(mp))
+		return true;
+
+	rgbno = xfs_rtb_to_rgbno(mp, rtbno, &rgno);
+	if (rgno >= mp->m_sb.sb_rgcount)
+		return false;
+
+	return xfs_verify_rgno_rgbno(mp, rgno, rgbno);
 }
 
 /* Verify that a realtime device extent is fully contained inside the volume. */
@@ -158,7 +193,14 @@ xfs_verify_rtbext(
 	if (!xfs_verify_rtbno(mp, rtbno))
 		return false;
 
-	return xfs_verify_rtbno(mp, rtbno + len - 1);
+	if (!xfs_verify_rtbno(mp, rtbno + len - 1))
+		return false;
+
+	if (xfs_has_rtgroups(mp) &&
+	    xfs_rtb_to_rgno(mp, rtbno) != xfs_rtb_to_rgno(mp, rtbno + len - 1))
+		return false;
+
+	return true;
 }
 
 /* Calculate the range of valid icount values. */