xfs: clean up filestreams helpers

Move xfs_filestream_peek_ag, xxfs_filestream_get_ag and xfs_filestream_put_ag
from xfs_filestream.h to xfs_filestream.c where it's only callers are, and
remove the inline marker while we're at it to let the compiler decide on the
inlining.  Also don't return a value from xfs_filestream_put_ag because
we don't need it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 0 insertions, 82 deletions

diff --git a/fs/xfs/xfs_filestream.h b/fs/xfs/xfs_filestream.h
index 260f757bbc5..09dd9af4543 100644
--- a/fs/xfs/xfs_filestream.h
+++ b/fs/xfs/xfs_filestream.h
@@ -42,88 +42,6 @@ extern ktrace_t *xfs_filestreams_trace_buf;
 
 #endif
 
-/*
- * Allocation group filestream associations are tracked with per-ag atomic
- * counters.  These counters allow _xfs_filestream_pick_ag() to tell whether a
- * particular AG already has active filestreams associated with it. The mount
- * point's m_peraglock is used to protect these counters from per-ag array
- * re-allocation during a growfs operation.  When xfs_growfs_data_private() is
- * about to reallocate the array, it calls xfs_filestream_flush() with the
- * m_peraglock held in write mode.
- *
- * Since xfs_mru_cache_flush() guarantees that all the free functions for all
- * the cache elements have finished executing before it returns, it's safe for
- * the free functions to use the atomic counters without m_peraglock protection.
- * This allows the implementation of xfs_fstrm_free_func() to be agnostic about
- * whether it was called with the m_peraglock held in read mode, write mode or
- * not held at all.  The race condition this addresses is the following:
- *
- *  - The work queue scheduler fires and pulls a filestream directory cache
- *    element off the LRU end of the cache for deletion, then gets pre-empted.
- *  - A growfs operation grabs the m_peraglock in write mode, flushes all the
- *    remaining items from the cache and reallocates the mount point's per-ag
- *    array, resetting all the counters to zero.
- *  - The work queue thread resumes and calls the free function for the element
- *    it started cleaning up earlier.  In the process it decrements the
- *    filestreams counter for an AG that now has no references.
- *
- * With a shrinkfs feature, the above scenario could panic the system.
- *
- * All other uses of the following macros should be protected by either the
- * m_peraglock held in read mode, or the cache's internal locking exposed by the
- * interval between a call to xfs_mru_cache_lookup() and a call to
- * xfs_mru_cache_done().  In addition, the m_peraglock must be held in read mode
- * when new elements are added to the cache.
- *
- * Combined, these locking rules ensure that no associations will ever exist in
- * the cache that reference per-ag array elements that have since been
- * reallocated.
- */
-/*
- * xfs_filestream_peek_ag is only used in tracing code
- */
-static inline int
-xfs_filestream_peek_ag(
-	xfs_mount_t	*mp,
-	xfs_agnumber_t	agno)
-{
-	struct xfs_perag *pag;
-	int		ret;
-
-	pag = xfs_perag_get(mp, agno);
-	ret = atomic_read(&pag->pagf_fstrms);
-	xfs_perag_put(pag);
-	return ret;
-}
-
-static inline int
-xfs_filestream_get_ag(
-	xfs_mount_t	*mp,
-	xfs_agnumber_t	agno)
-{
-	struct xfs_perag *pag;
-	int		ret;
-
-	pag = xfs_perag_get(mp, agno);
-	ret = atomic_inc_return(&pag->pagf_fstrms);
-	xfs_perag_put(pag);
-	return ret;
-}
-
-static inline int
-xfs_filestream_put_ag(
-	xfs_mount_t	*mp,
-	xfs_agnumber_t	agno)
-{
-	struct xfs_perag *pag;
-	int		ret;
-
-	pag = xfs_perag_get(mp, agno);
-	ret = atomic_dec_return(&pag->pagf_fstrms);
-	xfs_perag_put(pag);
-	return ret;
-}
-
 /* allocation selection flags */
 typedef enum xfs_fstrm_alloc {
 	XFS_PICK_USERDATA = 1,