From 5dde0a0cbbbccbbe7082f857bd6fbb3f5d2d8831 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 23 Sep 2024 13:41:27 -0700 Subject: [PATCH] xfs: encode the rtbitmap in big endian format 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 Reviewed-by: Christoph Hellwig --- 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 3b51ba841284..728e3cf5ad32 100644 --- a/fs/xfs/libxfs/xfs_format.h +++ b/fs/xfs/libxfs/xfs_format.h @@ -736,10 +736,12 @@ 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/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h index 2286a98ecb32..f9c0d2415901 100644 --- a/fs/xfs/libxfs/xfs_rtbitmap.h +++ b/fs/xfs/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; } /* -- 2.49.0