+ yaffs_FlushInodes(sb);
+ yaffs_UpdateDirtyDirectories(dev);
+ yaffs_FlushEntireDeviceCache(dev);
+ if(do_checkpoint)
+ yaffs_CheckpointSave(dev);
+}
+
+
+static unsigned yaffs_bg_gc_urgency(yaffs_Device *dev)
+{
+ unsigned erasedChunks = dev->nErasedBlocks * dev->param.nChunksPerBlock;
+ struct yaffs_LinuxContext *context = yaffs_DeviceToLC(dev);
+ unsigned scatteredFree = 0; /* Free chunks not in an erased block */
+
+ if(erasedChunks < dev->nFreeChunks)
+ scatteredFree = (dev->nFreeChunks - erasedChunks);
+
+ if(!context->bgRunning)
+ return 0;
+ else if(scatteredFree < (dev->param.nChunksPerBlock * 2))
+ return 0;
+ else if(erasedChunks > dev->nFreeChunks/2)
+ return 0;
+ else if(erasedChunks > dev->nFreeChunks/4)
+ return 1;
+ else
+ return 2;
+}
+
+static int yaffs_do_sync_fs(struct super_block *sb,
+ int request_checkpoint)
+{
+
+ yaffs_Device *dev = yaffs_SuperToDevice(sb);
+ unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
+ unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
+ int do_checkpoint;
+
+ T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+ (TSTR("yaffs_do_sync_fs: gc-urgency %d %s %s%s\n"),
+ gc_urgent,
+ sb->s_dirt ? "dirty" : "clean",
+ request_checkpoint ? "checkpoint requested" : "no checkpoint",
+ oneshot_checkpoint ? " one-shot" : "" ));
+
+ yaffs_GrossLock(dev);
+ do_checkpoint = ((request_checkpoint && !gc_urgent) ||
+ oneshot_checkpoint) &&
+ !dev->isCheckpointed;
+
+ if (sb->s_dirt || do_checkpoint) {
+ yaffs_FlushSuperBlock(sb, !dev->isCheckpointed && do_checkpoint);
+ sb->s_dirt = 0;
+ if(oneshot_checkpoint)
+ yaffs_auto_checkpoint &= ~4;
+ }
+ yaffs_GrossUnlock(dev);
+
+ return 0;
+}
+
+/*
+ * yaffs background thread functions .
+ * yaffs_BackgroundThread() the thread function
+ * yaffs_BackgroundStart() launches the background thread.
+ * yaffs_BackgroundStop() cleans up the background thread.
+ *
+ * NB:
+ * The thread should only run after the yaffs is initialised
+ * The thread should be stopped before yaffs is unmounted.
+ * The thread should not do any writing while the fs is in read only.
+ */
+
+#ifdef YAFFS_COMPILE_BACKGROUND
+
+void yaffs_background_waker(unsigned long data)
+{
+ wake_up_process((struct task_struct *)data);
+}
+
+static int yaffs_BackgroundThread(void *data)
+{
+ yaffs_Device *dev = (yaffs_Device *)data;
+ struct yaffs_LinuxContext *context = yaffs_DeviceToLC(dev);
+ unsigned long now = jiffies;
+ unsigned long next_dir_update = now;
+ unsigned long next_gc = now;
+ unsigned long expires;
+ unsigned int urgency;
+
+ int gcResult;
+ struct timer_list timer;
+
+ T(YAFFS_TRACE_BACKGROUND,
+ (TSTR("yaffs_background starting for dev %p\n"),
+ (void *)dev));
+
+ set_freezable();
+
+ while(context->bgRunning){
+ T(YAFFS_TRACE_BACKGROUND,
+ (TSTR("yaffs_background\n")));
+
+ if(kthread_should_stop())
+ break;
+
+ if(try_to_freeze())
+ continue;
+
+ yaffs_GrossLock(dev);
+
+ now = jiffies;
+
+ if(time_after(now, next_dir_update)){
+ yaffs_UpdateDirtyDirectories(dev);
+ next_dir_update = now + HZ;
+ }
+
+ if(time_after(now,next_gc)){
+ if(!dev->isCheckpointed){
+ urgency = yaffs_bg_gc_urgency(dev);
+ gcResult = yaffs_BackgroundGarbageCollect(dev, urgency);
+ if(urgency > 1)
+ next_gc = now + HZ/20+1;
+ else if(urgency > 0)
+ next_gc = now + HZ/10+1;
+ else
+ next_gc = now + HZ * 2;
+ } else /*
+ * gc not running so set to next_dir_update
+ * to cut down on wake ups
+ */
+ next_gc = next_dir_update;
+ }
+ yaffs_GrossUnlock(dev);
+#if 1
+ expires = next_dir_update;
+ if (time_before(next_gc,expires))
+ expires = next_gc;
+ if(time_before(expires,now))
+ expires = now + HZ;
+
+ Y_INIT_TIMER(&timer);
+ timer.expires = expires+1;
+ timer.data = (unsigned long) current;
+ timer.function = yaffs_background_waker;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ add_timer(&timer);
+ schedule();
+ del_timer_sync(&timer);
+#else
+ msleep(10);
+#endif
+ }
+
+ return 0;
+}
+
+static int yaffs_BackgroundStart(yaffs_Device *dev)
+{
+ int retval = 0;
+ struct yaffs_LinuxContext *context = yaffs_DeviceToLC(dev);
+
+ if(dev->readOnly)
+ return -1;
+
+ context->bgRunning = 1;
+
+ context->bgThread = kthread_run(yaffs_BackgroundThread,
+ (void *)dev,"yaffs-bg-%d",context->mount_id);
+
+ if(IS_ERR(context->bgThread)){
+ retval = PTR_ERR(context->bgThread);
+ context->bgThread = NULL;
+ context->bgRunning = 0;
+ }
+ return retval;
+}
+
+static void yaffs_BackgroundStop(yaffs_Device *dev)
+{
+ struct yaffs_LinuxContext *ctxt = yaffs_DeviceToLC(dev);
+
+ ctxt->bgRunning = 0;
+
+ if( ctxt->bgThread){
+ kthread_stop(ctxt->bgThread);
+ ctxt->bgThread = NULL;
+ }
+}
+#else
+static int yaffs_BackgroundThread(void *data)
+{
+ return 0;
+}
+
+static int yaffs_BackgroundStart(yaffs_Device *dev)
+{
+ return 0;
+}
+
+static void yaffs_BackgroundStop(yaffs_Device *dev)
+{
+}
+#endif
+
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static void yaffs_write_super(struct super_block *sb)
+#else
+static int yaffs_write_super(struct super_block *sb)
+#endif
+{
+ unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
+
+ T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
+ (TSTR("yaffs_write_super%s\n"),
+ request_checkpoint ? " checkpt" : ""));
+
+ yaffs_do_sync_fs(sb, request_checkpoint);
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 18))
+ return 0;
+#endif
+}
+
+
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
+static int yaffs_sync_fs(struct super_block *sb, int wait)
+#else
+static int yaffs_sync_fs(struct super_block *sb)
+#endif
+{
+ unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
+
+ T(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
+ (TSTR("yaffs_sync_fs%s\n"),
+ request_checkpoint ? " checkpt" : ""));
+
+ yaffs_do_sync_fs(sb, request_checkpoint);
+
+ return 0;
+}
+
+#ifdef YAFFS_USE_OWN_IGET
+
+static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
+{
+ struct inode *inode;
+ yaffs_Object *obj;
+ yaffs_Device *dev = yaffs_SuperToDevice(sb);
+
+ T(YAFFS_TRACE_OS,
+ (TSTR("yaffs_iget for %lu\n"), ino));
+
+ inode = iget_locked(sb, ino);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+
+ /* NB This is called as a side effect of other functions, but
+ * we had to release the lock to prevent deadlocks, so
+ * need to lock again.
+ */
+
+ yaffs_GrossLock(dev);
+