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| author | Darrick J. Wong <djwong@kernel.org> | 2023-12-03 09:19:44 -0800 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2023-12-06 18:45:17 -0800 |
| commit | cf8f0e6c1429be7652869059ea44696b72d5b726 (patch) | |
| tree | b1fb05f56e2f57cb10e9abdc6305a10ce34bafc0 | |
| parent | a6a38f309afc4a7ede01242b603f36c433997780 (diff) | |
| download | linux-stable-cf8f0e6c1429be7652869059ea44696b72d5b726.tar.gz linux-stable-cf8f0e6c1429be7652869059ea44696b72d5b726.tar.bz2 linux-stable-cf8f0e6c1429be7652869059ea44696b72d5b726.zip | |
xfs: fix 32-bit truncation in xfs_compute_rextslog
It's quite reasonable that some customer somewhere will want to
configure a realtime volume with more than 2^32 extents. If they try to
do this, the highbit32() call will truncate the upper bits of the
xfs_rtbxlen_t and produce the wrong value for rextslog. This in turn
causes the rsumlevels to be wrong, which results in a realtime summary
file that is the wrong length. Fix that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | fs/xfs/libxfs/xfs_rtbitmap.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c index 1c9fed76a356..30a2844f62e3 100644 --- a/fs/xfs/libxfs/xfs_rtbitmap.c +++ b/fs/xfs/libxfs/xfs_rtbitmap.c @@ -1132,14 +1132,16 @@ xfs_rtbitmap_blockcount( /* * Compute the maximum level number of the realtime summary file, as defined by - * mkfs. The use of highbit32 on a 64-bit quantity is a historic artifact that - * prohibits correct use of rt volumes with more than 2^32 extents. + * mkfs. The historic use of highbit32 on a 64-bit quantity prohibited correct + * use of rt volumes with more than 2^32 extents. */ uint8_t xfs_compute_rextslog( xfs_rtbxlen_t rtextents) { - return rtextents ? xfs_highbit32(rtextents) : 0; + if (!rtextents) + return 0; + return xfs_highbit64(rtextents); } /* |