[PATCH 4.19 88/93] NFSv4/pnfs: Fix a page lock leak in nfs_pageio_resend()

From: Greg Kroah-Hartman
Date: Wed Sep 04 2019 - 14:19:53 EST


[ Upstream commit f4340e9314dbfadc48758945f85fc3b16612d06f ]

If the attempt to resend the pages fails, we need to ensure that we
clean up those pages that were not transmitted.

Fixes: d600ad1f2bdb ("NFS41: pop some layoutget errors to application")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.5+
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/pagelist.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index d40bf560f3ca7..9cbd829b4ed5f 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1232,20 +1232,22 @@ static void nfs_pageio_complete_mirror(struct nfs_pageio_descriptor *desc,
int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
struct nfs_pgio_header *hdr)
{
- LIST_HEAD(failed);
+ LIST_HEAD(pages);

desc->pg_io_completion = hdr->io_completion;
desc->pg_dreq = hdr->dreq;
- while (!list_empty(&hdr->pages)) {
- struct nfs_page *req = nfs_list_entry(hdr->pages.next);
+ list_splice_init(&hdr->pages, &pages);
+ while (!list_empty(&pages)) {
+ struct nfs_page *req = nfs_list_entry(pages.next);

if (!nfs_pageio_add_request(desc, req))
- nfs_list_move_request(req, &failed);
+ break;
}
nfs_pageio_complete(desc);
- if (!list_empty(&failed)) {
- list_move(&failed, &hdr->pages);
- return desc->pg_error < 0 ? desc->pg_error : -EIO;
+ if (!list_empty(&pages)) {
+ int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
+ hdr->completion_ops->error_cleanup(&pages, err);
+ return err;
}
return 0;
}
--
2.20.1