Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

[safe/jmp/linux-2.6] / include / linux / iocontext.h

diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index 186807e..4da4a75 100644 (file)
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -1,6 +1,9 @@
 #ifndef IOCONTEXT_H
 #define IOCONTEXT_H
 
+#include <linux/radix-tree.h>
+#include <linux/rcupdate.h>
+
 /*
  * This is the per-process anticipatory I/O scheduler state.
  */
@@ -29,8 +32,8 @@ struct as_io_context {
 
 struct cfq_queue;
 struct cfq_io_context {
-       struct rb_node rb_node;
        void *key;
+       unsigned long dead_key;
 
        struct cfq_queue *cfqq[2];
 
@@ -48,19 +51,24 @@ struct cfq_io_context {
        sector_t seek_mean;
 
        struct list_head queue_list;
+       struct hlist_node cic_list;
 
        void (*dtor)(struct io_context *); /* destructor */
        void (*exit)(struct io_context *); /* called on task exit */
+
+       struct rcu_head rcu_head;
 };
 
 /*
- * This is the per-process I/O subsystem state.  It is refcounted and
- * kmalloc'ed. Currently all fields are modified in process io context
- * (apart from the atomic refcount), so require no locking.
+ * I/O subsystem state of the associated processes.  It is refcounted
+ * and kmalloc'ed. These could be shared between processes.
  */
 struct io_context {
-       atomic_t refcount;
-       struct task_struct *task;
+       atomic_long_t refcount;
+       atomic_t nr_tasks;
+
+       /* all the fields below are protected by this lock */
+       spinlock_t lock;
 
        unsigned short ioprio;
        unsigned short ioprio_changed;
@@ -72,8 +80,41 @@ struct io_context {
        int nr_batch_requests;     /* Number of requests left in the batch */
 
        struct as_io_context *aic;
-       struct rb_root cic_root;
+       struct radix_tree_root radix_root;
+       struct hlist_head cic_list;
        void *ioc_data;
 };
 
+static inline struct io_context *ioc_task_link(struct io_context *ioc)
+{
+       /*
+        * if ref count is zero, don't allow sharing (ioc is going away, it's
+        * a race).
+        */
+       if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
+               atomic_inc(&ioc->nr_tasks);
+               return ioc;
+       }
+
+       return NULL;
+}
+
+#ifdef CONFIG_BLOCK
+int put_io_context(struct io_context *ioc);
+void exit_io_context(void);
+struct io_context *get_io_context(gfp_t gfp_flags, int node);
+struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
+void copy_io_context(struct io_context **pdst, struct io_context **psrc);
+#else
+static inline void exit_io_context(void)
+{
+}
+
+struct io_context;
+static inline int put_io_context(struct io_context *ioc)
+{
+       return 1;
+}
+#endif
+
 #endif