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| author | Dave Chinner <david@fromorbit.com> | 2010-01-11 11:47:45 +0000 |
|---|---|---|
| committer | Alex Elder <aelder@sgi.com> | 2010-01-15 15:34:04 -0600 |
| commit | aed3bb90abaf0b42e8c8747e192f7bb97f445279 (patch) | |
| tree | 4619214ed42821792b05f4417cb95bde90abb562 /fs/xfs/xfs_mount.h | |
| parent | 1c1c6ebcf5284aee4910f3b906ac90c20e510c82 (diff) | |
| download | linux-3.10-aed3bb90abaf0b42e8c8747e192f7bb97f445279.tar.gz linux-3.10-aed3bb90abaf0b42e8c8747e192f7bb97f445279.tar.bz2 linux-3.10-aed3bb90abaf0b42e8c8747e192f7bb97f445279.zip | |
xfs: Reference count per-ag structures
Reference count the per-ag structures to ensure that we keep get/put
pairs balanced. Assert that the reference counts are zero at unmount
time to catch leaks. In future, reference counts will enable us to
safely remove perag structures by allowing us to detect when they
are no longer in use.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_mount.h')
| -rw-r--r-- | fs/xfs/xfs_mount.h | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index cfa7a5d22e7..16b22120b98 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -384,7 +384,7 @@ xfs_daddr_to_agbno(struct xfs_mount *mp, xfs_daddr_t d) } /* - * perag get/put wrappers for eventual ref counting + * perag get/put wrappers for ref counting */ static inline struct xfs_perag * xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno) @@ -393,6 +393,12 @@ xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno) spin_lock(&mp->m_perag_lock); pag = radix_tree_lookup(&mp->m_perag_tree, agno); + if (pag) { + ASSERT(atomic_read(&pag->pag_ref) >= 0); + /* catch leaks in the positive direction during testing */ + ASSERT(atomic_read(&pag->pag_ref) < 1000); + atomic_inc(&pag->pag_ref); + } spin_unlock(&mp->m_perag_lock); return pag; } @@ -400,7 +406,8 @@ xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno) static inline void xfs_perag_put(struct xfs_perag *pag) { - /* nothing to see here, move along */ + ASSERT(atomic_read(&pag->pag_ref) > 0); + atomic_dec(&pag->pag_ref); } /* |