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authorIngo Molnar <mingo@elte.hu>2008-07-14 11:37:46 +0200
committerIngo Molnar <mingo@elte.hu>2008-07-14 11:37:46 +0200
commitd59fdcf2ac501de99c3dfb452af5e254d4342886 (patch)
treead5e2efd6f8aacf2a08b1ed8a54ddf96642e83f3 /drivers/video
parent2387ce57a8167490d3b34a7e1ffa9a64a1a76244 (diff)
parentbce7f793daec3e65ec5c5705d2457b81fe7b5725 (diff)
Merge commit 'v2.6.26' into x86/core
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/fb_defio.c20
1 files changed, 19 insertions, 1 deletions
diff --git a/drivers/video/fb_defio.c b/drivers/video/fb_defio.c
index 24843fdd539..59df132cc37 100644
--- a/drivers/video/fb_defio.c
+++ b/drivers/video/fb_defio.c
@@ -74,6 +74,7 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
{
struct fb_info *info = vma->vm_private_data;
struct fb_deferred_io *fbdefio = info->fbdefio;
+ struct page *cur;
/* this is a callback we get when userspace first tries to
write to the page. we schedule a workqueue. that workqueue
@@ -83,7 +84,24 @@ static int fb_deferred_io_mkwrite(struct vm_area_struct *vma,
/* protect against the workqueue changing the page list */
mutex_lock(&fbdefio->lock);
- list_add(&page->lru, &fbdefio->pagelist);
+
+ /* we loop through the pagelist before adding in order
+ to keep the pagelist sorted */
+ list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+ /* this check is to catch the case where a new
+ process could start writing to the same page
+ through a new pte. this new access can cause the
+ mkwrite even when the original ps's pte is marked
+ writable */
+ if (unlikely(cur == page))
+ goto page_already_added;
+ else if (cur->index > page->index)
+ break;
+ }
+
+ list_add_tail(&page->lru, &cur->lru);
+
+page_already_added:
mutex_unlock(&fbdefio->lock);
/* come back after delay to process the deferred IO */