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| author | Brian Foster <bfoster@redhat.com> | 2021-10-14 22:56:09 +0300 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2021-10-19 21:45:13 +0300 |
| commit | 8ed004eb9d07a5d6114db3e97a166707c186262d (patch) | |
| tree | 707ae593d3e2af2aa08c5d8cd0eae1be8bcb8a40 /fs/xfs/libxfs/xfs_ag.h | |
| parent | f1788b5e5ee25bedf00bb4d25f82b93820d61189 (diff) | |
| download | linux-8ed004eb9d07a5d6114db3e97a166707c186262d.tar.xz | |
xfs: terminate perag iteration reliably on agcount
The for_each_perag_from() iteration macro relies on sb_agcount to
process every perag currently within EOFS from a given starting
point. It's perfectly valid to have perag structures beyond
sb_agcount, however, such as if a growfs is in progress. If a perag
loop happens to race with growfs in this manner, it will actually
attempt to process the post-EOFS perag where ->pag_agno ==
sb_agcount. This is reproduced by xfs/104 and manifests as the
following assert failure in superblock write verifier context:
XFS: Assertion failed: agno < mp->m_sb.sb_agcount, file: fs/xfs/libxfs/xfs_types.c, line: 22
Update the corresponding macro to only process perags that are
within the current sb_agcount.
Fixes: 58d43a7e3263 ("xfs: pass perags around in fsmap data dev functions")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/xfs/libxfs/xfs_ag.h')
| -rw-r--r-- | fs/xfs/libxfs/xfs_ag.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/xfs/libxfs/xfs_ag.h b/fs/xfs/libxfs/xfs_ag.h index 134e8635dee1..4585ebb3f450 100644 --- a/fs/xfs/libxfs/xfs_ag.h +++ b/fs/xfs/libxfs/xfs_ag.h @@ -142,7 +142,7 @@ xfs_perag_next( (pag) = xfs_perag_next((pag), &(agno))) #define for_each_perag_from(mp, agno, pag) \ - for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount, (pag)) + for_each_perag_range((mp), (agno), (mp)->m_sb.sb_agcount - 1, (pag)) #define for_each_perag(mp, agno, pag) \ |