[PATCH 4.19 49/79] NFSv2: Fix eof handling

From: Greg Kroah-Hartman
Date: Thu Sep 19 2019 - 18:32:08 EST


From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>

[ Upstream commit 71affe9be45a5c60b9772e1b2701710712637274 ]

If we received a reply from the server with a zero length read and
no error, then that implies we are at eof.

Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfs/proc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index e0c257bd62b93..89fa9c706b380 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -594,7 +594,8 @@ static int nfs_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
/* Emulate the eof flag, which isn't normally needed in NFSv2
* as it is guaranteed to always return the file attributes
*/
- if (hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
+ if ((hdr->res.count == 0 && hdr->args.count > 0) ||
+ hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
hdr->res.eof = 1;
}
return 0;
--
2.20.1