Shuffle files around more logically.

client/ublkdev-c++/Makefile → c++-client/Makefile

@@ -3,7 +3,7 @@
 
 
 TARGETS = libublkdev.so ublkdev-s3
-CPPFLAGS = -I. -I../../src
+CPPFLAGS = -I. -I../kernel
 CXXFLAGS = -std=c++11 -fPIC -Wall -g
 
 LIB_SRCS = ublkdev.cc

client/ublkdev-c++/s3.cc → c++-client/s3.cc

@@ -948,29 +948,34 @@ void UBDS3Handler::run() {
             // Event ready.
             cerr << "Thread " << std::this_thread::get_id() << " processing a message" << endl;
 
-            try {
-                m_message.ubd_size = m_buffer_size;
-                m_ubd.getRequest(m_message);
-            }
-            catch (UBDError const &e) {
-                if (e.getError() == ENOMEM) {
-                    // Resize the buffer
-                    try {
-                        cerr << "ENOMEM -- allocated " << m_buffer_size
-                             << " bytes but need " << m_message.ubd_size
-                             << " bytes" << endl;
-                        resizeBuffer(m_message.ubd_size);
-                        cerr << "Now have " << m_buffer_size << " bytes" << endl;
-                    }
-                    catch (bad_alloc &) {
-                        cerr << "Thread " << std::this_thread::get_id()
-                             << " failed to allocate " << message.ubd_size
-                             << " bytes; exiting." << endl;
-                        break;
+            while (true) {
+                try {
+                    m_message.ubd_size = m_buffer_size;
+                    m_ubd.getRequest(m_message);
+                    break;
+                }
+                catch (UBDError const &e) {
+                    if (e.getError() == ENOMEM) {
+                        // Resize the buffer
+                        try {
+                            cerr << std::this_thread::get_id()
+                                 << ": ENOMEM -- allocated " << m_buffer_size
+                                 << " bytes but need " << m_message.ubd_size
+                                 << " bytes" << endl;
+                            resizeBuffer(m_message.ubd_size);
+                            cerr << std::this_thread::get_id()
+                                 << ": Now have " << m_buffer_size << " bytes" << endl;
+                        }
+                        catch (bad_alloc &) {
+                            cerr << "Thread " << std::this_thread::get_id()
+                                 << " failed to allocate " << message.ubd_size
+                                 << " bytes; exiting." << endl;
+                            break;
+                        }
                     }
                 }
             }
-
+            
             handleUBDRequest();
         }
     }

src/ublkdev.c → kernel/ublkdev.c

@@ -930,6 +930,7 @@ static long ubdctl_ioctl_getrequest(
 
     // Wait for a message to become available *and* a tag slot to become
     // available.
+    ubd_debug("About to enter spinlock to wait for a message");
     spin_lock_irqsave(&dev->wait.lock, lock_flags);
     if (wait_event_interruptible_locked(
             dev->wait,
@@ -940,24 +941,40 @@ static long ubdctl_ioctl_getrequest(
         spin_unlock_irqrestore(&dev->wait.lock, lock_flags);
         return -ERESTARTSYS;
     }
+    ubd_debug("Message and tag available");
 
     msg.ubd_nsectors = blk_rq_sectors(req);
     msg.ubd_first_sector = blk_rq_pos(req);
 
     // Fill in the remaining details.
     if ((req->cmd_flags & REQ_DISCARD) != 0) {
+        ubd_debug("Got a discard request (first_sector=%llu, nsectors=%llu)",
+                  (long long unsigned) msg.ubd_first_sector,
+                  (long long unsigned) msg.ubd_nsectors);
         msg.ubd_msgtype = UBD_MSGTYPE_DISCARD;
         msg.ubd_size = 0;
     } else if ((req->cmd_flags & REQ_FLUSH) != 0) {
+        ubd_debug("Got a flush request (first_sector=%llu, nsectors=%llu)",
+                  (long long unsigned) msg.ubd_first_sector,
+                  (long long unsigned) msg.ubd_nsectors);
         msg.ubd_msgtype = UBD_MSGTYPE_FLUSH;
         msg.ubd_size = 0;
     } else if (rq_data_dir(req) == READ) {
+        ubd_debug("Got a read request (first_sector=%llu, nsectors=%llu)",
+                  (long long unsigned) msg.ubd_first_sector,
+                  (long long unsigned) msg.ubd_nsectors);
+
         msg.ubd_msgtype = UBD_MSGTYPE_READ;
         msg.ubd_size = 0;
     } else {
         void __user *dest = msg.ubd_data;
         uint32_t write_size = msg.ubd_nsectors << 9;
 
+        ubd_debug("Got a write request (first_sector=%llu, nsectors=%llu)",
+                  (long long unsigned) msg.ubd_first_sector,
+                  (long long unsigned) msg.ubd_nsectors);
+
+
         BUG_ON(rq_data_dir(req) != WRITE);
 
         if (write_size > msg.ubd_size) {
@@ -1005,6 +1022,8 @@ static long ubdctl_ioctl_getrequest(
         }
     }
 
+    ubd_debug("Allocated tag %u", tag);
+
     BUG_ON(tag == max_pending_reply);
     msg.ubd_tag = tag;
     ACCESS_ONCE(dev->pending_reply[tag]) = req;
@@ -1027,6 +1046,7 @@ static long ubdctl_ioctl_getrequest(
     }
 
     spin_unlock_irqrestore(&dev->wait.lock, lock_flags);
+    ubd_debug("Left spinlock");
 
     return 0;
 }