[3.0-stable PATCH 19/36] xfs: limit specualtive delalloc to maxioffset

Mark Tinguely
2012-12-03T23:40:42Z

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From: Dave Chinner <dchinner@redhat.com>

Upstream commit: 3ed9116e8a3e9c0870b2076340b3da9b8f900f3b

Speculative delayed allocation beyond EOF near the maximum supported
file offset can result in creating delalloc extents beyond
mp->m_maxioffset (8EB). These can never be trimmed during
xfs_free_eof_blocks() because they are beyond mp->m_maxioffset, and
that results in assert failures in xfs_fs_destroy_inode() due to
delalloc blocks still being present. xfstests 071 exposes this
problem.

Limit speculative delalloc to mp->m_maxioffset to avoid this
problem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
---
fs/xfs/xfs_iomap.c | 9 +++++++++
1 file changed, 9 insertions(+)

Index: b/fs/xfs/xfs_iomap.c
===================================================================
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -417,6 +417,15 @@ retry:
return error;
}

+ /*
+ * Make sure preallocation does not create extents beyond the range we
+ * actually support in this filesystem.
+ */
+ if (last_fsb > XFS_B_TO_FSB(mp, mp->m_maxioffset))
+ last_fsb = XFS_B_TO_FSB(mp, mp->m_maxioffset);
+
+ ASSERT(last_fsb > offset_fsb);
+
nimaps = XFS_WRITE_IMAPS;
firstblock = NULLFSBLOCK;
error = xfs_bmapi(NULL, ip, offset_fsb,