From: Darrick J. Wong <djwong@xxxxxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
libxfs/xfs_format.h | 4 +++-
libxfs/xfs_rtbitmap.h | 7 ++++++-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 016ee4ff537440..cd9457ed5873fe 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 2286a98ecb32bb..f9c0d241590104 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;
}
/*
