From a647e4bc5ce697e25ff50d2e22de68a581b1ed38 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 26 Jun 2006 00:27:46 -0700 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/bitmap.c | 20 ++------------------ 1 file changed, 2 insertions(+), 18 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 2e257d5998bc..609e68d3e1bc 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -332,7 +332,6 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait) /* 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 @@ static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits, 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 @@ static void bitmap_mask_state(struct bitmap *bitmap, enum bitmap_state bits, default: BUG(); } kunmap_atomic(sb, KM_USER0); - put_page(bitmap->sb_page); } /* @@ -641,7 +638,6 @@ static void drain_write_queues(struct bitmap *bitmap) while ((item = dequeue_page(bitmap))) { /* don't bother to wait */ - put_page(item->page); mempool_free(item, bitmap->write_pool); } } @@ -744,11 +740,6 @@ static void bitmap_file_set_bit(struct bitmap *bitmap, sector_t block) 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 @@ int bitmap_daemon_work(struct bitmap *bitmap) 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 @@ int bitmap_daemon_work(struct bitmap *bitmap) 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 @@ int bitmap_daemon_work(struct bitmap *bitmap) 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 @@ int bitmap_daemon_work(struct bitmap *bitmap) set_page_attr(bitmap, lastpage, BITMAP_PAGE_NEEDWRITE); spin_unlock_irqrestore(&bitmap->lock, flags); } - - put_page(lastpage); } return err; @@ -1140,7 +1125,6 @@ static void bitmap_writeback(struct bitmap *bitmap) 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", -- 2.20.1