Merge branch 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.33' of git://git.kernel.dk/linux-2.6-block: (113 commits)
  cfq-iosched: Do not access cfqq after freeing it
  block: include linux/err.h to use ERR_PTR
  cfq-iosched: use call_rcu() instead of doing grace period stall on queue exit
  blkio: Allow CFQ group IO scheduling even when CFQ is a module
  blkio: Implement dynamic io controlling policy registration
  blkio: Export some symbols from blkio as its user CFQ can be a module
  block: Fix io_context leak after failure of clone with CLONE_IO
  block: Fix io_context leak after clone with CLONE_IO
  cfq-iosched: make nonrot check logic consistent
  io controller: quick fix for blk-cgroup and modular CFQ
  cfq-iosched: move IO controller declerations to a header file
  cfq-iosched: fix compile problem with !CONFIG_CGROUP
  blkio: Documentation
  blkio: Wait on sync-noidle queue even if rq_noidle = 1
  blkio: Implement group_isolation tunable
  blkio: Determine async workload length based on total number of queues
  blkio: Wait for cfq queue to get backlogged if group is empty
  blkio: Propagate cgroup weight updation to cfq groups
  blkio: Drop the reference to queue once the task changes cgroup
  blkio: Provide some isolation between groups
  ...

1 files changed, 127 insertions, 0 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
new file mode 100644
index 000000000000..4d316df863b4
--- /dev/null
+++ b/block/blk-cgroup.h
@@ -0,0 +1,127 @@
+#ifndef _BLK_CGROUP_H
+#define _BLK_CGROUP_H
+/*
+ * Common Block IO controller cgroup interface
+ *
+ * Based on ideas and code from CFQ, CFS and BFQ:
+ * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
+ *
+ * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
+ *                    Paolo Valente <paolo.valente@unimore.it>
+ *
+ * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
+ *                    Nauman Rafique <nauman@google.com>
+ */
+
+#include <linux/cgroup.h>
+
+#ifdef CONFIG_BLK_CGROUP
+
+struct blkio_cgroup {
+        struct cgroup_subsys_state css;
+        unsigned int weight;
+        spinlock_t lock;
+        struct hlist_head blkg_list;
+};
+
+struct blkio_group {
+        /* An rcu protected unique identifier for the group */
+        void *key;
+        struct hlist_node blkcg_node;
+        unsigned short blkcg_id;
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+        /* Store cgroup path */
+        char path[128];
+        /* How many times this group has been removed from service tree */
+        unsigned long dequeue;
+#endif
+        /* The device MKDEV(major, minor), this group has been created for */
+        dev_t   dev;
+
+        /* total disk time and nr sectors dispatched by this group */
+        unsigned long time;
+        unsigned long sectors;
+};
+
+extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
+extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
+
+typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
+typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
+                                                unsigned int weight);
+
+struct blkio_policy_ops {
+        blkio_unlink_group_fn *blkio_unlink_group_fn;
+        blkio_update_group_weight_fn *blkio_update_group_weight_fn;
+};
+
+struct blkio_policy_type {
+        struct list_head list;
+        struct blkio_policy_ops ops;
+};
+
+/* Blkio controller policy registration */
+extern void blkio_policy_register(struct blkio_policy_type *);
+extern void blkio_policy_unregister(struct blkio_policy_type *);
+
+#else
+
+struct blkio_group {
+};
+
+struct blkio_policy_type {
+};
+
+static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
+static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
+
+#endif
+
+#define BLKIO_WEIGHT_MIN        100
+#define BLKIO_WEIGHT_MAX        1000
+#define BLKIO_WEIGHT_DEFAULT    500
+
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+static inline char *blkg_path(struct blkio_group *blkg)
+{
+        return blkg->path;
+}
+void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
+                                unsigned long dequeue);
+#else
+static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
+static inline void blkiocg_update_blkio_group_dequeue_stats(
+                        struct blkio_group *blkg, unsigned long dequeue) {}
+#endif
+
+#ifdef CONFIG_BLK_CGROUP
+extern struct blkio_cgroup blkio_root_cgroup;
+extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
+extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+                        struct blkio_group *blkg, void *key, dev_t dev);
+extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
+extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
+                                                void *key);
+void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
+                        unsigned long time, unsigned long sectors);
+#else
+struct cgroup;
+static inline struct blkio_cgroup *
+cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
+
+static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
+                        struct blkio_group *blkg, void *key, dev_t dev)
+{
+}
+
+static inline int
+blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
+
+static inline struct blkio_group *
+blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
+static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
+                        unsigned long time, unsigned long sectors)
+{
+}
+#endif
+#endif /* _BLK_CGROUP_H */