Re: shutdown umount hangs

[Russell Cattelan <cattelan@xxxxxxxxxxx>]

Ok try this patch...
Since we haven't been able to reproduce the problem here I
don't know if it will help or not, but give it a try.
It doesn't appear to make thing any worse :-)

--
Russell Cattelan
--
Digital Elves inc. -- Currently on loan to SGI
Linux XFS core developer.


--- /usr/tmp/TmpDir.18409-0/linux/fs/pagebuf/page_buf.c_1.72    Wed Apr  4 
20:07:15 2001
+++ linux/fs/pagebuf/page_buf.c Wed Apr  4 20:06:35 2001
@@ -2172,11 +2172,6 @@
                                continue;
                          }
 
-                               pb->pb_flags &= ~PBF_DELWRI;
-                               pb->pb_flags |= PBF_WRITE;
-                               if (flags & PBDF_WAIT)
-                                       pb->pb_flags &= ~PBF_ASYNC;
-
                                /* insert a place holder */
                                list_add(&pb_marker_ptr->pb_list, curr);
 
@@ -2184,40 +2179,33 @@
                                                &pb_daemon->pb_delwrite_lock,
                                                save);
 
-                               if (pb->pb_flags & _PBF_LOCKABLE){
-                                 if (flags & PBDF_PINCOUNT){
-                                       /* if we are doing this pin count thing 
and we can't get the lock just skip it for now */
-                                       }if (!pagebuf_cond_lock(pb)){
-                                         __pagebuf_iorequest(pb);
-                                       } else {
-                                         (*pincount)++;
-                                         /* make it async again... don't want 
to wait on in below */
-                                         pb->pb_flags |= PBF_ASYNC;
-                                       }
-                                 }else {
-                                       pagebuf_lock(pb);
+                                /* if (pb->pb_flags & _PBF_LOCKABLE){ */
+                               /* meta data pagebufs better be lockable 
pagebuf's */
+                                 assert(pb->pb_flags & _PBF_LOCKABLE); 
+       
+                                 if (!pagebuf_ispin(pb) && (0 == 
pagebuf_cond_lock(pb))){
+                                       pb->pb_flags &= ~PBF_DELWRI;
+                                       pb->pb_flags |= PBF_WRITE;
+                                       if (flags & PBDF_WAIT)
+                                         pb->pb_flags &= ~PBF_ASYNC;
+
                                        __pagebuf_iorequest(pb);
+                                 } else {
+                                       if (flags & PBDF_PINCOUNT) 
+                                         (*pincount)++;
                                  }
-
-                               spin_lock_irqsave(
-                                               &pb_daemon->pb_delwrite_lock,
-                                               save);
+                               spin_lock_irqsave(&pb_daemon->pb_delwrite_lock, 
save);
                                /*
                                 * ok got the lock back; pick up the place
                                 * holder and continue on
                                 */
                                curr = pb_marker_ptr->pb_list.next;
                                list_del(&pb_marker_ptr->pb_list);
-                       } else {
-                               /* not doing anything with current...
-                                * move on to the next one */
-                               curr = curr->next;
-                       }
-               } else {
-                       /* not doing anything with current...
-                        * move on to the next one */
-                       curr = curr->next;
-               }
+                       } 
+               } 
+               /* not doing anything with current...
+                * move on to the next one */
+               curr = curr->next;
        }
 
        spin_unlock_irqrestore(&pb_daemon->pb_delwrite_lock, save);
@@ -2270,14 +2258,13 @@
                PB_TRACE(pb, PB_TRACE_REC(walkq3), pagebuf_ispin(pb));
 
                if (pb->pb_target == target) {
-                       int     sync = (pb->pb_flags & PBF_ASYNC) == 0;
                        list_add(&pb_marker_ptr->pb_list, curr);
 
                        spin_unlock_irqrestore(
                                        &pb_daemon->pb_delwrite_lock,
                                        flags);
 
-                       if (sync) {
+                       if (!(pb->pb_flags & PBF_ASYNC)) {
                                pagebuf_iowait(pb);
                                pb->pb_flags |= PBF_ASYNC;
                                pagebuf_delwri_dequeue(pb);