[PATCH] md/bitmap: remove unnecessary page reference manipulations from md/bitmap code
md/bitmap gets a collection of pages representing the bitmap when it
initialises the bitmap, and puts all the references when discarding the
bitmap.
It also occasionally takes extra references without any good reason, and
sometimes drops them ... though it doesn't always drop them, which can result
in a memory leak.
This patch removes the unnecessary 'get_page' calls, and the corresponding
'put_page' calls.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 2e257d5..609e68d 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -332,7 +332,6 @@
/* add to list to be waited for */
struct page_list *item = mempool_alloc(bitmap->write_pool, GFP_NOIO);
item->page = page;
- get_page(page);
spin_lock(&bitmap->write_lock);
list_add(&item->list, &bitmap->complete_pages);
spin_unlock(&bitmap->write_lock);
@@ -548,7 +547,6 @@
spin_unlock_irqrestore(&bitmap->lock, flags);
return;
}
- get_page(bitmap->sb_page);
spin_unlock_irqrestore(&bitmap->lock, flags);
sb = (bitmap_super_t *)kmap_atomic(bitmap->sb_page, KM_USER0);
switch (op) {
@@ -559,7 +557,6 @@
default: BUG();
}
kunmap_atomic(sb, KM_USER0);
- put_page(bitmap->sb_page);
}
/*
@@ -641,7 +638,6 @@
while ((item = dequeue_page(bitmap))) {
/* don't bother to wait */
- put_page(item->page);
mempool_free(item, bitmap->write_pool);
}
}
@@ -744,11 +740,6 @@
page = filemap_get_page(bitmap, chunk);
bit = file_page_offset(chunk);
-
- /* make sure the page stays cached until it gets written out */
- if (! test_page_attr(bitmap, page, BITMAP_PAGE_DIRTY))
- get_page(page);
-
/* set the bit */
kaddr = kmap_atomic(page, KM_USER0);
if (bitmap->flags & BITMAP_HOSTENDIAN)
@@ -1028,10 +1019,9 @@
if (!test_page_attr(bitmap, page, BITMAP_PAGE_CLEAN)) {
int need_write = test_page_attr(bitmap, page,
BITMAP_PAGE_NEEDWRITE);
- if (need_write) {
- get_page(page);
+ if (need_write)
clear_page_attr(bitmap, page, BITMAP_PAGE_NEEDWRITE);
- }
+
spin_unlock_irqrestore(&bitmap->lock, flags);
if (need_write) {
switch (write_page(bitmap, page, 0)) {
@@ -1043,13 +1033,11 @@
default:
bitmap_file_kick(bitmap);
}
- put_page(page);
}
continue;
}
/* grab the new page, sync and release the old */
- get_page(page);
if (lastpage != NULL) {
if (test_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE)) {
clear_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
@@ -1063,7 +1051,6 @@
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
- put_page(lastpage);
if (err)
bitmap_file_kick(bitmap);
} else
@@ -1117,8 +1104,6 @@
set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE);
spin_unlock_irqrestore(&bitmap->lock, flags);
}
-
- put_page(lastpage);
}
return err;
@@ -1140,7 +1125,6 @@
PRINTK("finished page writeback: %p\n", page);
err = PageError(page);
- put_page(page);
if (err) {
printk(KERN_WARNING "%s: bitmap file writeback "
"failed (page %lu): %d\n",