patch-2.4.23 linux-2.4.23/fs/buffer.c

• Lines: 166
• Date: 2003-11-28 10:26:21.000000000 -0800
• Orig file: linux-2.4.22/fs/buffer.c
• Orig date: 2003-08-25 04:44:43.000000000 -0700

diff -urN linux-2.4.22/fs/buffer.c linux-2.4.23/fs/buffer.c
@@ -88,6 +88,13 @@
 static int osync_buffers_list(struct list_head *);
 static void __refile_buffer(struct buffer_head *);
 
+/*
+ * A global sysctl-controlled flag which puts the machine into "laptop mode"
+ */
+int laptop_mode;
+
+static DECLARE_WAIT_QUEUE_HEAD(kupdate_wait);
+
 /* This is used by some architectures to estimate available memory. */
 atomic_t buffermem_pages = ATOMIC_INIT(0);
 
@@ -612,7 +619,7 @@
 	if (buffer_attached(bh))
 		list_del(&bh->b_inode_buffers);
 	set_buffer_attached(bh);
-	list_add(&bh->b_inode_buffers, list);
+	list_add_tail(&bh->b_inode_buffers, list);
 	spin_unlock(&lru_list_lock);
 }
 
@@ -1016,7 +1023,7 @@
 	dirty *= 100;
 	dirty_limit = tot * bdf_prm.b_un.nfract_stop_bdflush;
 
-	if (dirty > dirty_limit)
+	if (!laptop_mode && dirty > dirty_limit)
 		return 0;
 	return 1;
 }
@@ -1066,6 +1073,8 @@
 void mark_buffer_dirty(struct buffer_head *bh)
 {
 	if (!atomic_set_buffer_dirty(bh)) {
+		if (block_dump)
+			printk("%s: dirtied buffer\n", current->comm);
 		__mark_dirty(bh);
 		balance_dirty();
 	}
@@ -1077,6 +1086,12 @@
 }
 EXPORT_SYMBOL(set_buffer_flushtime);
 
+inline int get_buffer_flushtime(void)
+{
+	return bdf_prm.b_un.interval;
+}
+EXPORT_SYMBOL(get_buffer_flushtime);
+
 /*
  * A buffer may need to be moved from one buffer list to another
  * (e.g. in case it is not shared any more). Handle this.
@@ -1749,7 +1764,7 @@
 		if (!buffer_mapped(bh)) {
 			if (iblock < lblock) {
 				if (get_block(inode, iblock, bh, 0))
-					continue;
+					SetPageError(page);
 			}
 			if (!buffer_mapped(bh)) {
 				memset(kmap(page) + i*blocksize, 0, blocksize);
@@ -1769,10 +1784,11 @@
 
 	if (!nr) {
 		/*
-		 * all buffers are uptodate - we can set the page
-		 * uptodate as well.
+		 * All buffers are uptodate - we can set the page uptodate
+		 * as well. But not if get_block() returned an error.
 		 */
-		SetPageUptodate(page);
+		if (!PageError(page))
+			SetPageUptodate(page);
 		UnlockPage(page);
 		return 0;
 	}
@@ -2751,10 +2767,10 @@
 #endif
 
 	printk("Buffer memory:   %6dkB\n",
-			atomic_read(&buffermem_pages) << (PAGE_SHIFT-10));
+		atomic_read(&buffermem_pages) << (PAGE_SHIFT-10));
 
-	printk("Cache memory:   %6dkB\n",
-			(atomic_read(&page_cache_size)- atomic_read(&buffermem_pages)) << (PAGE_SHIFT-10));
+	printk("Cache memory:   %6ldkB\n",
+		(page_cache_size - atomic_read(&buffermem_pages)) << (PAGE_SHIFT-10));
 
 #ifdef CONFIG_SMP /* trylock does nothing on UP and so we could deadlock */
 	if (!spin_trylock(&lru_list_lock))
@@ -2859,6 +2875,12 @@
 	wake_up_interruptible(&bdflush_wait);
 }
 
+void wakeup_kupdate(void)
+{
+	if (waitqueue_active(&kupdate_wait))
+		wake_up(&kupdate_wait);
+}
+
 /* 
  * Here we attempt to write back old buffers.  We also try to flush inodes 
  * and supers as well, since this function is essentially "update", and 
@@ -2879,7 +2901,9 @@
 
 		spin_lock(&lru_list_lock);
 		bh = lru_list[BUF_DIRTY];
-		if (!bh || time_before(jiffies, bh->b_flushtime))
+		if (!bh)
+			break;
+		if (time_before(jiffies, bh->b_flushtime) && !laptop_mode)
 			break;
 		if (write_some_buffers(NODEV))
 			continue;
@@ -3027,33 +3051,41 @@
 	complete((struct completion *)startup);
 
 	for (;;) {
+		DECLARE_WAITQUEUE(wait, tsk);
+
+		add_wait_queue(&kupdate_wait, &wait);
+
 		/* update interval */
 		interval = bdf_prm.b_un.interval;
 		if (interval) {
 			tsk->state = TASK_INTERRUPTIBLE;
 			schedule_timeout(interval);
 		} else {
-		stop_kupdate:
 			tsk->state = TASK_STOPPED;
 			schedule(); /* wait for SIGCONT */
 		}
+		remove_wait_queue(&kupdate_wait, &wait);
 		/* check for sigstop */
 		if (signal_pending(tsk)) {
-			int stopped = 0;
+			int sig, stopped = 0;
+			struct siginfo info;
+
 			spin_lock_irq(&tsk->sigmask_lock);
-			if (sigismember(&tsk->pending.signal, SIGSTOP)) {
-				sigdelset(&tsk->pending.signal, SIGSTOP);
+			sig = dequeue_signal(&current->blocked, &info);
+			if (sig == SIGSTOP)
 				stopped = 1;
-			}
-			recalc_sigpending(tsk);
 			spin_unlock_irq(&tsk->sigmask_lock);
-			if (stopped)
-				goto stop_kupdate;
+			if (stopped) {
+				tsk->state = TASK_STOPPED;
+				schedule(); /* wait for SIGCONT */
+			}
 		}
 #ifdef DEBUG
 		printk(KERN_DEBUG "kupdate() activated...\n");
 #endif
 		sync_old_buffers();
+		if (laptop_mode)
+			fsync_dev(NODEV);
 		run_task_queue(&tq_disk);
 	}
 }