orangefs: have ..._clean_interrupted_...() wait for copy to/from daemon

* turn all those list_del(&op->list) into list_del_init()
* don't pick ops that are already given up in control device
  ->read()/->write_iter().
* have orangefs_clean_interrupted_operation() notice if op is currently
  being copied to/from daemon (by said ->read()/->write_iter()) and
  wait for that to finish.
* when we are done copying to/from daemon and find that it had been
  given up while we were doing that, wake the waiting ..._clean_interrupted_...

As the result, we are guaranteed that orangefs_clean_interrupted_operation(op)
doesn't return until nobody else can see op.  Moreover, we don't need to play
with op refcounts anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c
index 89c282a..f7914f5 100644 (file)
--- a/fs/orangefs/devorangefs-req.c
+++ b/fs/orangefs/devorangefs-req.c
@@ -58,9 +58,9 @@ static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag)
                                 next,
                                 &htable_ops_in_progress[index],
                                 list) {
-               if (op->tag == tag && !op_state_purged(op)) {
+               if (op->tag == tag && !op_state_purged(op) &&
+                   !op_state_given_up(op)) {
                        list_del_init(&op->list);
-                       get_op(op); /* increase ref count. */
                        spin_unlock(&htable_ops_in_progress_lock);
                        return op;
                }
@@ -133,7 +133,7 @@ restart:
                __s32 fsid;
                /* This lock is held past the end of the loop when we break. */
                spin_lock(&op->lock);
-               if (unlikely(op_state_purged(op))) {
+               if (unlikely(op_state_purged(op) || op_state_given_up(op))) {
                        spin_unlock(&op->lock);
                        continue;
                }
@@ -199,13 +199,12 @@ restart:
         */
        if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) {
                gossip_err("orangefs: ERROR: Current op already queued.\n");
-               list_del(&cur_op->list);
+               list_del_init(&cur_op->list);
                spin_unlock(&cur_op->lock);
                spin_unlock(&orangefs_request_list_lock);
                return -EAGAIN;
        }
        list_del_init(&cur_op->list);
-       get_op(op);
        spin_unlock(&orangefs_request_list_lock);
 
        spin_unlock(&cur_op->lock);
@@ -230,7 +229,7 @@ restart:
        if (unlikely(op_state_given_up(cur_op))) {
                spin_unlock(&cur_op->lock);
                spin_unlock(&htable_ops_in_progress_lock);
-               op_release(cur_op);
+               complete(&cur_op->waitq);
                goto restart;
        }
 
@@ -242,7 +241,6 @@ restart:
        orangefs_devreq_add_op(cur_op);
        spin_unlock(&cur_op->lock);
        spin_unlock(&htable_ops_in_progress_lock);
-       op_release(cur_op);
 
        /* The client only asks to read one size buffer. */
        return MAX_DEV_REQ_UPSIZE;
@@ -258,10 +256,12 @@ error:
        if (likely(!op_state_given_up(cur_op))) {
                set_op_state_waiting(cur_op);
                list_add(&cur_op->list, &orangefs_request_list);
+               spin_unlock(&cur_op->lock);
+       } else {
+               spin_unlock(&cur_op->lock);
+               complete(&cur_op->waitq);
        }
-       spin_unlock(&cur_op->lock);
        spin_unlock(&orangefs_request_list_lock);
-       op_release(cur_op);
        return -EFAULT;
 }
 
@@ -405,11 +405,11 @@ wakeup:
                put_cancel(op);
        } else if (unlikely(op_state_given_up(op))) {
                spin_unlock(&op->lock);
+               complete(&op->waitq);
        } else {
                set_op_state_serviced(op);
                spin_unlock(&op->lock);
        }
-       op_release(op);
        return ret;
 
 Efault:

diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 1d20ead..7d0c8b3 100644 (file)
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -259,7 +259,7 @@ static inline void set_op_state_purged(struct orangefs_kernel_op_s *op)
 {
        spin_lock(&op->lock);
        if (unlikely(op_is_cancel(op))) {
-               list_del(&op->list);
+               list_del_init(&op->list);
                spin_unlock(&op->lock);
                put_cancel(op);
        } else {

diff --git a/fs/orangefs/waitqueue.c b/fs/orangefs/waitqueue.c
index d980240..3f9e430 100644 (file)
--- a/fs/orangefs/waitqueue.c
+++ b/fs/orangefs/waitqueue.c
@@ -208,15 +208,20 @@ static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s
         * Called with op->lock held.
         */
        op->op_state |= OP_VFS_STATE_GIVEN_UP;
-
-       if (op_state_waiting(op)) {
+       /* from that point on it can't be moved by anybody else */
+       if (list_empty(&op->list)) {
+               /* caught copying to/from daemon */
+               BUG_ON(op_state_serviced(op));
+               spin_unlock(&op->lock);
+               wait_for_completion(&op->waitq);
+       } else if (op_state_waiting(op)) {
                /*
                 * upcall hasn't been read; remove op from upcall request
                 * list.
                 */
                spin_unlock(&op->lock);
                spin_lock(&orangefs_request_list_lock);
-               list_del(&op->list);
+               list_del_init(&op->list);
                spin_unlock(&orangefs_request_list_lock);
                gossip_debug(GOSSIP_WAIT_DEBUG,
                             "Interrupted: Removed op %p from request_list\n",
@@ -225,23 +230,16 @@ static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s
                /* op must be removed from the in progress htable */
                spin_unlock(&op->lock);
                spin_lock(&htable_ops_in_progress_lock);
-               list_del(&op->list);
+               list_del_init(&op->list);
                spin_unlock(&htable_ops_in_progress_lock);
                gossip_debug(GOSSIP_WAIT_DEBUG,
                             "Interrupted: Removed op %p"
                             " from htable_ops_in_progress\n",
                             op);
-       } else if (!op_state_serviced(op)) {
+       } else {
                spin_unlock(&op->lock);
                gossip_err("interrupted operation is in a weird state 0x%x\n",
                           op->op_state);
-       } else {
-               /*
-                * It is not intended for execution to flow here,
-                * but having this unlock here makes sparse happy.
-                */
-               gossip_err("%s: can't get here.\n", __func__);
-               spin_unlock(&op->lock);
        }
        reinit_completion(&op->waitq);
 }