[PATCH 5.15 668/913] NFS: Dont loop forever in nfs_do_recoalesce()

From: Greg Kroah-Hartman
Date: Tue Apr 05 2022 - 22:08:29 EST

From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

[ Upstream commit d02d81efc7564b4d5446a02e0214a164cf00b1f3 ]

If __nfs_pageio_add_request() fails to add the request, it will return
with either desc->pg_error < 0, or mirror->pg_recoalesce will be set, so
we are guaranteed either to exit the function altogether, or to loop.

However if there is nothing left in mirror->pg_list to coalesce, we must
exit, so make sure that we clear mirror->pg_recoalesce every time we

Reported-by: Olga Kornievskaia <aglo@xxxxxxxxx>
Fixes: 70536bf4eb07 ("NFS: Clean up reset of the mirror accounting variables")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
fs/nfs/pagelist.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index cc232d1f16f2..b1130dc200d2 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1227,6 +1227,7 @@ static int nfs_do_recoalesce(struct nfs_pageio_descriptor *desc)

do {
list_splice_init(&mirror->pg_list, &head);
+ mirror->pg_recoalesce = 0;

while (!list_empty(&head)) {
struct nfs_page *req;