xfs: encode the rtsummary in big endian format

Currently, the ondisk realtime summary file counters are 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.  Encode the summary
information in big endian format, like most of the rest of the
filesystem.

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

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index cd9457e..f56ff9f 100644 (file)
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -719,10 +719,12 @@ union xfs_rtword_raw {
 
 /*
  * Realtime summary counts are 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_suminfo_raw {
        __u32           old;
+       __be32          rtg;
 };
 
 /*

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index f9c0d24..7be7649 100644 (file)
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -300,6 +300,8 @@ xfs_suminfo_get(
 {
        union xfs_suminfo_raw   *info = xfs_rsumblock_infoptr(args, index);
 
+       if (xfs_has_rtgroups(args->mp))
+               return be32_to_cpu(info->rtg);
        return info->old;
 }
 
@@ -312,6 +314,11 @@ xfs_suminfo_add(
 {
        union xfs_suminfo_raw   *info = xfs_rsumblock_infoptr(args, index);
 
+       if (xfs_has_rtgroups(args->mp)) {
+               be32_add_cpu(&info->rtg, delta);
+               return be32_to_cpu(info->rtg);
+       }
+
        info->old += delta;
        return info->old;
 }

diff --git a/fs/xfs/scrub/rtsummary.c b/fs/xfs/scrub/rtsummary.c
index 8f3f69b..49fc625 100644 (file)
--- a/fs/xfs/scrub/rtsummary.c
+++ b/fs/xfs/scrub/rtsummary.c
@@ -151,6 +151,11 @@ xchk_rtsum_inc(
        struct xfs_mount        *mp,
        union xfs_suminfo_raw   *v)
 {
+       if (xfs_has_rtgroups(mp)) {
+               be32_add_cpu(&v->rtg, 1);
+               return be32_to_cpu(v->rtg);
+       }
+
        v->old += 1;
        return v->old;
 }