From: Darrick J. Wong <darrick.wong@oracle.com>
Date: Mon, 6 Apr 2020 19:04:25 +0000 (-0700)
Subject: xfs: validate the realtime geometry in xfs_validate_sb_common
X-Git-Tag: libxfs-5.7-sync_2020-04-28^0
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=19d32c905bd3b14cc5e5448b01fb71ae1b2d8d41;p=xfsprogs-dev.git

xfs: validate the realtime geometry in xfs_validate_sb_common

Source kernel commit: f8e566c0f5e1fd8de33ccec6eb1ff815cd4b0dc3

Validate the geometry of the realtime geometry when we mount the
filesystem, so that we don't abruptly shut down the filesystem later on.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---

diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h
index 97e1e32b..885282c8 100644
--- a/libxfs/libxfs_priv.h
+++ b/libxfs/libxfs_priv.h
@@ -268,6 +268,18 @@ div64_u64_rem(
 	return dividend / divisor;
 }
 
+static inline uint64_t
+div_u64(uint64_t dividend, uint32_t divisor)
+{
+	return dividend / divisor;
+}
+
+static inline uint64_t
+howmany_64(uint64_t dividend, uint32_t divisor)
+{
+	return div_u64(dividend + divisor - 1, divisor);
+}
+
 #define min_t(type,x,y) \
 	({ type __x = (x); type __y = (y); __x < __y ? __x: __y; })
 #define max_t(type,x,y) \
diff --git a/libxfs/xfs_sb.c b/libxfs/xfs_sb.c
index e26b9016..d37d60b3 100644
--- a/libxfs/xfs_sb.c
+++ b/libxfs/xfs_sb.c
@@ -325,6 +325,38 @@ xfs_validate_sb_common(
 		return -EFSCORRUPTED;
 	}
 
+	/* Validate the realtime geometry; stolen from xfs_repair */
+	if (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE ||
+	    sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) {
+		xfs_notice(mp,
+			"realtime extent sanity check failed");
+		return -EFSCORRUPTED;
+	}
+
+	if (sbp->sb_rblocks == 0) {
+		if (sbp->sb_rextents != 0 || sbp->sb_rbmblocks != 0 ||
+		    sbp->sb_rextslog != 0 || sbp->sb_frextents != 0) {
+			xfs_notice(mp,
+				"realtime zeroed geometry check failed");
+			return -EFSCORRUPTED;
+		}
+	} else {
+		uint64_t	rexts;
+		uint64_t	rbmblocks;
+
+		rexts = div_u64(sbp->sb_rblocks, sbp->sb_rextsize);
+		rbmblocks = howmany_64(sbp->sb_rextents,
+				       NBBY * sbp->sb_blocksize);
+
+		if (sbp->sb_rextents != rexts ||
+		    sbp->sb_rextslog != xfs_highbit32(sbp->sb_rextents) ||
+		    sbp->sb_rbmblocks != rbmblocks) {
+			xfs_notice(mp,
+				"realtime geometry sanity check failed");
+			return -EFSCORRUPTED;
+		}
+	}
+
 	if (sbp->sb_unit) {
 		if (!xfs_sb_version_hasdalign(sbp) ||
 		    sbp->sb_unit > sbp->sb_width ||