[PATCH] switch to use of ->key to get cfq_data by cfq_io_context

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 15 insertions, 11 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 63ed11f8795d..42f990f2763d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1212,7 +1212,7 @@ static void cfq_free_io_context(struct cfq_io_context *cic)
  */
 static void cfq_exit_single_io_context(struct cfq_io_context *cic)
 {
-        struct cfq_data *cfqd = cic->cfqq->cfqd;
+        struct cfq_data *cfqd = cic->key;
         request_queue_t *q = cfqd->queue;
 
         WARN_ON(!irqs_disabled());
@@ -1224,6 +1224,7 @@ static void cfq_exit_single_io_context(struct cfq_io_context *cic)
 
         cfq_put_queue(cic->cfqq);
         cic->cfqq = NULL;
+        cic->key = NULL;
         spin_unlock(q->queue_lock);
 }
 
@@ -1318,14 +1319,17 @@ static void cfq_init_prio_data(struct cfq_queue *cfqq)
         cfq_clear_cfqq_prio_changed(cfqq);
 }
 
-static inline void changed_ioprio(struct cfq_queue *cfqq)
+static inline void changed_ioprio(struct cfq_io_context *cic)
 {
-        if (cfqq) {
-                struct cfq_data *cfqd = cfqq->cfqd;
-
+        struct cfq_data *cfqd = cic->key;
+        struct cfq_queue *cfqq;
+        if (cfqd) {
                 spin_lock(cfqd->queue->queue_lock);
-                cfq_mark_cfqq_prio_changed(cfqq);
-                cfq_init_prio_data(cfqq);
+                cfqq = cic->cfqq;
+                if (cfqq) {
+                        cfq_mark_cfqq_prio_changed(cfqq);
+                        cfq_init_prio_data(cfqq);
+                }
                 spin_unlock(cfqd->queue->queue_lock);
         }
 }
@@ -1337,10 +1341,10 @@ static int cfq_ioc_set_ioprio(struct io_context *ioc, unsigned int ioprio)
 {
         struct cfq_io_context *cic = ioc->cic;
 
-        changed_ioprio(cic->cfqq);
+        changed_ioprio(cic);
 
         list_for_each_entry(cic, &cic->list, list)
-                changed_ioprio(cic->cfqq);
+                changed_ioprio(cic);
 
         return 0;
 }
@@ -1429,10 +1433,10 @@ cfq_get_io_context(struct cfq_data *cfqd, pid_t pid, gfp_t gfp_mask)
                  * manually increment generic io_context usage count, it
                  * cannot go away since we are already holding one ref to it
                  */
-                ioc->cic = cic;
-                ioc->set_ioprio = cfq_ioc_set_ioprio;
                 cic->ioc = ioc;
                 cic->key = cfqd;
+                ioc->set_ioprio = cfq_ioc_set_ioprio;
+                ioc->cic = cic;
         } else {
                 struct cfq_io_context *__cic;