Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c2e43a22 authored by Laura Abbott's avatar Laura Abbott Committed by Prasad Sodagudi
Browse files

fs: fuse: Workaround for CMA migration 



The FUSE file system may hold references to pages for long
periods of time, preventing migration from occurring. If a CMA
page is used here, CMA allocations may fail. Work around this
by swapping out a CMA page for a non-CMA page when working with
the FUSE file system.

Change-Id: Id763ea833ee125c8732ae3759ec9e20d94aa8424
Signed-off-by: default avatarLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: default avatarPrasad Sodagudi <psodagud@codeaurora.org>
parent 630fdcc6

fs/fuse/file.c

+35 −0
Original line number Diff line number Diff line
@@ -900,6 +900,41 @@ static int fuse_readpages_fill(void *_data, struct page *page) 
		return -EIO;

	}



#ifdef CONFIG_CMA

	if (is_cma_pageblock(page)) {

		struct page *oldpage = page, *newpage;

		int err;



		/* make sure that old page is not free in-between the calls */

		page_cache_get(oldpage);



		newpage = alloc_page(GFP_HIGHUSER);

		if (!newpage) {

			page_cache_release(oldpage);

			return -ENOMEM;

		}



		err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);

		if (err) {

			__free_page(newpage);

			page_cache_release(oldpage);

			return err;

		}



		/*

		 * Decrement the count on new page to make page cache the only

		 * owner of it

		 */

		lock_page(newpage);

		put_page(newpage);



		/* finally release the old page and swap pointers */

		unlock_page(oldpage);

		page_cache_release(oldpage);

		page = newpage;

	}

#endif



	page_cache_get(page);

	req->pages[req->num_pages] = page;

	req->page_descs[req->num_pages].length = PAGE_SIZE;