Commit f53056c4 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher
Browse files

gfs2: Multi-block allocations in gfs2_page_mkwrite 



In gfs2_page_mkwrite's gfs2_allocate_page_backing helper, try to
allocate as many blocks at once as we need.  Pass in the size of the
requested allocation.

Fixes: 35af80ae ("gfs2: don't use buffer_heads in gfs2_allocate_page_backing")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent 39c3a948

fs/gfs2/file.c

+8 −7
Original line number Diff line number Diff line
@@ -381,27 +381,28 @@ static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size) 
/**

 * gfs2_allocate_page_backing - Allocate blocks for a write fault

 * @page: The (locked) page to allocate backing for

 * @length: Size of the allocation

 *

 * We try to allocate all the blocks required for the page in one go.  This

 * might fail for various reasons, so we keep trying until all the blocks to

 * back this page are allocated.  If some of the blocks are already allocated,

 * that is ok too.

 */

static int gfs2_allocate_page_backing(struct page *page)

static int gfs2_allocate_page_backing(struct page *page, unsigned int length)

{

	u64 pos = page_offset(page);

	u64 size = PAGE_SIZE;



	do {

		struct iomap iomap = { };



		if (gfs2_iomap_get_alloc(page->mapping->host, pos, 1, &iomap))

		if (gfs2_iomap_get_alloc(page->mapping->host, pos, length, &iomap))

			return -EIO;



		iomap.length = min(iomap.length, size);

		size -= iomap.length;

		if (length < iomap.length)

			iomap.length = length;

		length -= iomap.length;

		pos += iomap.length;

	} while (size > 0);

	} while (length > 0);



	return 0;

}
@@ -501,7 +502,7 @@ static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf) 
	if (gfs2_is_stuffed(ip))

		ret = gfs2_unstuff_dinode(ip, page);

	if (ret == 0)

		ret = gfs2_allocate_page_backing(page);

		ret = gfs2_allocate_page_backing(page, PAGE_SIZE);



out_trans_end:

	if (ret)

CRA Git | Maintained and supported by SUSTech CRA and CCSE