From: Darrick J. Wong <djwong@kernel.org>
Date: Mon, 25 Nov 2024 21:14:23 +0000 (-0800)
Subject: xfs: encode the rtbitmap in big endian format
X-Git-Tag: v6.13.0~111
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5d1ceb55d5705de02ec807dd12c685ee107ac7a4;p=thirdparty%2Fxfsprogs-dev.git

xfs: encode the rtbitmap in big endian format

Source kernel commit: eba42c2c53c8b8905307b702c93dffef0719a896

Currently, the ondisk realtime bitmap file is accessed in units of
32-bit words.  There's no endian translation of the contents of this
file, which means that the Bad Things Happen(tm) if you go from (say)
x86 to powerpc.  Since we have a new feature flag, let's take the
opportunity to enforce an endianness on the file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 016ee4ff..cd9457ed 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -709,10 +709,12 @@ struct xfs_agfl {
 
 /*
  * Realtime bitmap information is accessed by the word, which is currently
- * stored in host-endian format.
+ * stored in host-endian format.  Starting with the realtime groups feature,
+ * the words are stored in be32 ondisk.
  */
 union xfs_rtword_raw {
 	__u32		old;
+	__be32		rtg;
 };
 
 /*
diff --git a/libxfs/xfs_rtbitmap.h b/libxfs/xfs_rtbitmap.h
index 2286a98e..f9c0d241 100644
--- a/libxfs/xfs_rtbitmap.h
+++ b/libxfs/xfs_rtbitmap.h
@@ -210,6 +210,8 @@ xfs_rtbitmap_getword(
 {
 	union xfs_rtword_raw	*word = xfs_rbmblock_wordptr(args, index);
 
+	if (xfs_has_rtgroups(args->mp))
+		return be32_to_cpu(word->rtg);
 	return word->old;
 }
 
@@ -222,7 +224,10 @@ xfs_rtbitmap_setword(
 {
 	union xfs_rtword_raw	*word = xfs_rbmblock_wordptr(args, index);
 
-	word->old = value;
+	if (xfs_has_rtgroups(args->mp))
+		word->rtg = cpu_to_be32(value);
+	else
+		word->old = value;
 }
 
 /*