From: Darrick J. Wong <djwong@xxxxxxxxxx>
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.
The natural format of a bitmap is (IMHO) little endian, because the byte
offsets of the bitmap data should always increase in step with the
information being indexed.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_format.h | 4 +++-
fs/xfs/libxfs/xfs_rtbitmap.h | 7 ++++++-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index 7178bd463c1c0..77422fbd3372e 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -749,10 +749,12 @@ 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 le32 ondisk.
*/
union xfs_rtword_raw {
__u32 old;
+ __le32 rtg;
};
/*
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index e1cf47d2a9281..588689e53ba39 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -208,6 +208,8 @@ xfs_rtbitmap_getword(
{
union xfs_rtword_raw *word = xfs_rbmblock_wordptr(args, index);
+ if (xfs_has_rtgroups(args->mp))
+ return le32_to_cpu(word->rtg);
return word->old;
}
@@ -220,7 +222,10 @@ 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_le32(value);
+ else
+ word->old = value;
}
/*
