ocfs2: Change metadata caching locks to an operations structure.

We don't really want to cart around too many new fields on the
ocfs2_caching_info structure.  So let's wrap all our access of the
parent object in a set of operations.  One pointer on caching_info, and
more flexibility to boot.

Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/fs/ocfs2/uptodate.h b/fs/ocfs2/uptodate.h
index bd749e1434f1..3b33eb88d320 100644
--- a/fs/ocfs2/uptodate.h
+++ b/fs/ocfs2/uptodate.h
@@ -26,12 +26,38 @@
 #ifndef OCFS2_UPTODATE_H
 #define OCFS2_UPTODATE_H
 
+/*
+ * The caching code relies on locking provided by the user of
+ * struct ocfs2_caching_info.  These operations connect that up.
+ */
+struct ocfs2_caching_operations {
+	/*
+	 * A u64 representing the owning structure.  Usually this
+	 * is the block number (i_blkno or whatnot).  This is used so
+	 * that caching log messages can identify the owning structure.
+	 */
+	u64	(*co_owner)(struct ocfs2_caching_info *ci);
+
+	/*
+	 * Lock and unlock the caching data.  These will not sleep, and
+	 * should probably be spinlocks.
+	 */
+	void	(*co_cache_lock)(struct ocfs2_caching_info *ci);
+	void	(*co_cache_unlock)(struct ocfs2_caching_info *ci);
+
+	/*
+	 * Lock and unlock for disk I/O.  These will sleep, and should
+	 * be mutexes.
+	 */
+	void	(*co_io_lock)(struct ocfs2_caching_info *ci);
+	void	(*co_io_unlock)(struct ocfs2_caching_info *ci);
+};
+
 int __init init_ocfs2_uptodate_cache(void);
 void exit_ocfs2_uptodate_cache(void);
 
 void ocfs2_metadata_cache_init(struct ocfs2_caching_info *ci,
-			       spinlock_t *cache_lock,
-			       struct mutex *io_mutex);
+			       const struct ocfs2_caching_operations *ops);
 void ocfs2_metadata_cache_purge(struct inode *inode);
 
 int ocfs2_buffer_uptodate(struct inode *inode,