SUNRPC: Clean up the initialisation of priority queue scheduling info.

We want the default scheduling priority (priority == 0) to remain
RPC_PRIORITY_NORMAL.

Also ensure that the priority wait queue scheduling is per process id
instead of sometimes being per thread, and sometimes being per inode.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 29 insertions, 42 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index f9f5fc13dc7d..5bcc764e501a 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -331,8 +331,6 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_direct_req *dreq,
                 rpc_init_task(&data->task, &task_setup_data);
                 NFS_PROTO(inode)->read_setup(data);
 
-                data->task.tk_cookie = (unsigned long) inode;
-
                 rpc_execute(&data->task);
 
                 dprintk("NFS: %5u initiated direct read call "
@@ -465,9 +463,6 @@ static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
                 rpc_init_task(&data->task, &task_setup_data);
                 NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE);
 
-                data->task.tk_priority = RPC_PRIORITY_NORMAL;
-                data->task.tk_cookie = (unsigned long) inode;
-
                 /*
                  * We're called via an RPC callback, so BKL is already held.
                  */
@@ -534,8 +529,6 @@ static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
         rpc_init_task(&data->task, &task_setup_data);
         NFS_PROTO(data->inode)->commit_setup(data, 0);
 
-        data->task.tk_priority = RPC_PRIORITY_NORMAL;
-        data->task.tk_cookie = (unsigned long)data->inode;
         /* Note: task.tk_ops->rpc_release will free dreq->commit_data */
         dreq->commit_data = NULL;
 
@@ -718,9 +711,6 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_direct_req *dreq,
                 rpc_init_task(&data->task, &task_setup_data);
                 NFS_PROTO(inode)->write_setup(data, sync);
 
-                data->task.tk_priority = RPC_PRIORITY_NORMAL;
-                data->task.tk_cookie = (unsigned long) inode;
-
                 rpc_execute(&data->task);
 
                 dprintk("NFS: %5u initiated direct write call "
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index c7f0d5ebd451..8f1eb08ccffa 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -189,8 +189,6 @@ static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
         rpc_init_task(&data->task, &task_setup_data);
         NFS_PROTO(inode)->read_setup(data);
 
-        data->task.tk_cookie = (unsigned long)inode;
-
         dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
                         data->task.tk_pid,
                         inode->i_sb->s_id,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index c4376606f106..8d90e90ccd47 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -753,7 +753,7 @@ static void nfs_writepage_release(struct nfs_page *req)
         nfs_clear_page_tag_locked(req);
 }
 
-static inline int flush_task_priority(int how)
+static int flush_task_priority(int how)
 {
         switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) {
                 case FLUSH_HIGHPRI:
@@ -775,11 +775,13 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
 {
         struct inode *inode = req->wb_context->path.dentry->d_inode;
         int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
+        int priority = flush_task_priority(how);
         struct rpc_task_setup task_setup_data = {
                 .rpc_client = NFS_CLIENT(inode),
                 .callback_ops = call_ops,
                 .callback_data = data,
                 .flags = flags,
+                .priority = priority,
         };
 
         /* Set up the RPC argument and reply structs
@@ -805,9 +807,6 @@ static void nfs_write_rpcsetup(struct nfs_page *req,
         rpc_init_task(&data->task, &task_setup_data);
         NFS_PROTO(inode)->write_setup(data, how);
 
-        data->task.tk_priority = flush_task_priority(how);
-        data->task.tk_cookie = (unsigned long)inode;
-
         dprintk("NFS: %5u initiated write call "
                 "(req %s/%Ld, %u bytes @ offset %Lu)\n",
                 data->task.tk_pid,
@@ -1152,11 +1151,13 @@ static void nfs_commit_rpcsetup(struct list_head *head,
         struct nfs_page *first = nfs_list_entry(head->next);
         struct inode *inode = first->wb_context->path.dentry->d_inode;
         int flags = (how & FLUSH_SYNC) ? 0 : RPC_TASK_ASYNC;
+        int priority = flush_task_priority(how);
         struct rpc_task_setup task_setup_data = {
                 .rpc_client = NFS_CLIENT(inode),
                 .callback_ops = &nfs_commit_ops,
                 .callback_data = data,
                 .flags = flags,
+                .priority = priority,
         };
 
         /* Set up the RPC argument and reply structs
@@ -1180,9 +1181,6 @@ static void nfs_commit_rpcsetup(struct list_head *head,
         rpc_init_task(&data->task, &task_setup_data);
         NFS_PROTO(inode)->commit_setup(data, how);
 
-        data->task.tk_priority = flush_task_priority(how);
-        data->task.tk_cookie = (unsigned long)inode;
-        
         dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
 }
 
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h
index d974421d7647..c9444fdc23ac 100644
--- a/include/linux/sunrpc/sched.h
+++ b/include/linux/sunrpc/sched.h
@@ -56,8 +56,6 @@ struct rpc_task {
         __u8                    tk_garb_retry;
         __u8                    tk_cred_retry;
 
-        unsigned long           tk_cookie;      /* Cookie for batching tasks */
-
         /*
          * timeout_fn   to be executed by timer bottom half
          * callback     to be executed after waking up
@@ -78,7 +76,6 @@ struct rpc_task {
         struct timer_list       tk_timer;       /* kernel timer */
         unsigned long           tk_timeout;     /* timeout for rpc_sleep() */
         unsigned short          tk_flags;       /* misc flags */
-        unsigned char           tk_priority : 2;/* Task priority */
         unsigned long           tk_runstate;    /* Task run status */
         struct workqueue_struct *tk_workqueue;  /* Normally rpciod, but could
                                                  * be any workqueue
@@ -94,6 +91,9 @@ struct rpc_task {
         unsigned long           tk_start;       /* RPC task init timestamp */
         long                    tk_rtt;         /* round-trip time (jiffies) */
 
+        pid_t                   tk_owner;       /* Process id for batching tasks */
+        unsigned char           tk_priority : 2;/* Task priority */
+
 #ifdef RPC_DEBUG
         unsigned short          tk_pid;         /* debugging aid */
 #endif
@@ -123,6 +123,7 @@ struct rpc_task_setup {
         const struct rpc_call_ops *callback_ops;
         void *callback_data;
         unsigned short flags;
+        signed char priority;
 };
 
 /*
@@ -187,10 +188,10 @@ struct rpc_task_setup {
  * Note: if you change these, you must also change
  * the task initialization definitions below.
  */
-#define RPC_PRIORITY_LOW        0
-#define RPC_PRIORITY_NORMAL     1
-#define RPC_PRIORITY_HIGH       2
-#define RPC_NR_PRIORITY         (RPC_PRIORITY_HIGH+1)
+#define RPC_PRIORITY_LOW        (-1)
+#define RPC_PRIORITY_NORMAL     (0)
+#define RPC_PRIORITY_HIGH       (1)
+#define RPC_NR_PRIORITY         (1 + RPC_PRIORITY_HIGH - RPC_PRIORITY_LOW)
 
 /*
  * RPC synchronization objects
@@ -198,7 +199,7 @@ struct rpc_task_setup {
 struct rpc_wait_queue {
         spinlock_t              lock;
         struct list_head        tasks[RPC_NR_PRIORITY]; /* task queue for each priority level */
-        unsigned long           cookie;                 /* cookie of last task serviced */
+        pid_t                   owner;                  /* process id of last task serviced */
         unsigned char           maxpriority;            /* maximum priority (0 if queue is not a priority queue) */
         unsigned char           priority;               /* current priority */
         unsigned char           count;                  /* # task groups remaining serviced so far */
diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index 10216989309c..b9061bcf6fc1 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -135,7 +135,7 @@ static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct r
         if (unlikely(task->tk_priority > queue->maxpriority))
                 q = &queue->tasks[queue->maxpriority];
         list_for_each_entry(t, q, u.tk_wait.list) {
-                if (t->tk_cookie == task->tk_cookie) {
+                if (t->tk_owner == task->tk_owner) {
                         list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
                         return;
                 }
@@ -208,26 +208,26 @@ static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int
         queue->count = 1 << (priority * 2);
 }
 
-static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
+static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
 {
-        queue->cookie = cookie;
+        queue->owner = pid;
         queue->nr = RPC_BATCH_COUNT;
 }
 
 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
 {
         rpc_set_waitqueue_priority(queue, queue->maxpriority);
-        rpc_set_waitqueue_cookie(queue, 0);
+        rpc_set_waitqueue_owner(queue, 0);
 }
 
-static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
+static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues)
 {
         int i;
 
         spin_lock_init(&queue->lock);
         for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
                 INIT_LIST_HEAD(&queue->tasks[i]);
-        queue->maxpriority = maxprio;
+        queue->maxpriority = nr_queues - 1;
         rpc_reset_waitqueue_priority(queue);
 #ifdef RPC_DEBUG
         queue->name = qname;
@@ -236,12 +236,12 @@ static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const c
 
 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
 {
-        __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
+        __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY);
 }
 
 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
 {
-        __rpc_init_priority_wait_queue(queue, qname, 0);
+        __rpc_init_priority_wait_queue(queue, qname, 1);
 }
 EXPORT_SYMBOL_GPL(rpc_init_wait_queue);
 
@@ -456,12 +456,12 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu
         struct rpc_task *task;
 
         /*
-         * Service a batch of tasks from a single cookie.
+         * Service a batch of tasks from a single owner.
          */
         q = &queue->tasks[queue->priority];
         if (!list_empty(q)) {
                 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
-                if (queue->cookie == task->tk_cookie) {
+                if (queue->owner == task->tk_owner) {
                         if (--queue->nr)
                                 goto out;
                         list_move_tail(&task->u.tk_wait.list, q);
@@ -470,7 +470,7 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu
                  * Check if we need to switch queues.
                  */
                 if (--queue->count)
-                        goto new_cookie;
+                        goto new_owner;
         }
 
         /*
@@ -492,8 +492,8 @@ static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queu
 
 new_queue:
         rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
-new_cookie:
-        rpc_set_waitqueue_cookie(queue, task->tk_cookie);
+new_owner:
+        rpc_set_waitqueue_owner(queue, task->tk_owner);
 out:
         __rpc_wake_up_task(task);
         return task;
@@ -830,8 +830,8 @@ void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setu
         task->tk_garb_retry = 2;
         task->tk_cred_retry = 2;
 
-        task->tk_priority = RPC_PRIORITY_NORMAL;
-        task->tk_cookie = (unsigned long)current;
+        task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW;
+        task->tk_owner = current->tgid;
 
         /* Initialize workqueue for async tasks */
         task->tk_workqueue = rpciod_workqueue;