Commit 56517ab9 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFS: Fix an Oopsable condition in __nfs_pageio_add_request() 



Ensure that nfs_pageio_error_cleanup() resets the mirror array contents,
so that the structure reflects the fact that it is now empty.
Also change the test in nfs_pageio_do_add_request() to be more robust by
checking whether or not the list is empty rather than relying on the
value of pg_count.

Fixes: a7d42ddb ("nfs: add mirroring support to pgio layer")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent e86be3a0

fs/nfs/pagelist.c

+5 −4
Original line number Diff line number Diff line
@@ -1094,15 +1094,16 @@ nfs_pageio_do_add_request(struct nfs_pageio_descriptor *desc, 
	struct nfs_page *prev = NULL;

	unsigned int size;



	if (mirror->pg_count != 0) {

		prev = nfs_list_entry(mirror->pg_list.prev);

	} else {

	if (list_empty(&mirror->pg_list)) {

		if (desc->pg_ops->pg_init)

			desc->pg_ops->pg_init(desc, req);

		if (desc->pg_error < 0)

			return 0;

		mirror->pg_base = req->wb_pgbase;

	}

		mirror->pg_count = 0;

		mirror->pg_recoalesce = 0;

	} else

		prev = nfs_list_entry(mirror->pg_list.prev);



	if (desc->pg_maxretrans && req->wb_nio > desc->pg_maxretrans) {

		if (NFS_SERVER(desc->pg_inode)->flags & NFS_MOUNT_SOFTERR)