[Suspend2][ 08/32] [Suspend2] Finish and cleanup all outstanding I/O.

[Nigel Cunningham <nigel@suspend2.net>]

Wait for all outstanding I/O to complete, then clean it all up and free the
io_info structs.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 kernel/power/suspend_block_io.c |   42 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/kernel/power/suspend_block_io.c b/kernel/power/suspend_block_io.c
index 6f8b29e..5b93ad2 100644
--- a/kernel/power/suspend_block_io.c
+++ b/kernel/power/suspend_block_io.c
@@ -333,3 +333,45 @@ static void do_bio_wait(int caller)
 	suspend_cleanup_some_completed_io();
 }
 
+/*
+ * suspend_finish_all_io
+ *
+ * Description:	Finishes all IO and frees all IO info struct pages.
+ */
+static void suspend_finish_all_io(void)
+{
+	struct io_info *this, *next = NULL;
+	unsigned long flags;
+
+	/* Wait for all I/O to complete. */
+	while (atomic_read(&outstanding_io))
+		do_bio_wait(2);
+
+	spin_lock_irqsave(&ioinfo_free_lock, flags);
+	
+	/* 
+	 * Two stages, to avoid using freed pages.
+	 *
+	 * First free all io_info structs on a page except the first.
+	 */
+	list_for_each_entry_safe(this, next, &ioinfo_free, list) {
+		if (((unsigned long) this) & ~PAGE_MASK)
+			list_del(&this->list);
+	}
+
+	/* 
+	 * Now we have only one reference to each page, and can safely
+	 * free pages, knowing we're not going to be trying to access the
+	 * same page after freeing it.
+	 */
+	list_for_each_entry_safe(this, next, &ioinfo_free, list) {
+		list_del(&this->list);
+		free_page((unsigned long) this);
+		infopages--;
+		suspend_message(SUSPEND_MEMORY, SUSPEND_VERBOSE, 0,
+				"[FreedIOPage %lx]", this);
+	}
+	
+	spin_unlock_irqrestore(&ioinfo_free_lock, flags);
+}
+

--
Nigel Cunningham		nigel at suspend2 dot net
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