2023-03-13 11:24:08

by Jeff Layton

[permalink] [raw]
Subject: [pynfs PATCH v2 1/5] nfs4.0: add a retry loop on NFS4ERR_DELAY to compound function

The latest knfsd server is "courteous" in that it will not revoke a
lease held by an expired client until there is competing access for it.
When there is competing access, it can now return NFS4ERR_DELAY until
the old client is expired. I've seen this happen when running pynfs in
a loop against a server with only 4g of memory.

The v4.0 compound handler doesn't retry automatically on NFS4ERR_DELAY
like the v4.1 version does. Add support for it using the same timeouts
as the v4.1 compound handler.

Cc: Dai Ngo <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
---
nfs4.0/nfs4lib.py | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/nfs4.0/nfs4lib.py b/nfs4.0/nfs4lib.py
index 9b074f02b91f..eddcd862bc2f 100644
--- a/nfs4.0/nfs4lib.py
+++ b/nfs4.0/nfs4lib.py
@@ -338,12 +338,21 @@ class NFS4Client(rpc.RPCClient):
un_p = self.nfs4unpacker
p.reset()
p.pack_COMPOUND4args(compoundargs)
- res = self.call(NFSPROC4_COMPOUND, p.get_buffer())
- un_p.reset(res)
- res = un_p.unpack_COMPOUND4res()
- if SHOW_TRAFFIC:
- print(res)
- un_p.done()
+ res = None
+
+ # NFS servers can return NFS4ERR_DELAY at any time for any reason.
+ # Just delay a second and retry the call again in that event. If
+ # it fails after 10 retries then just give up.
+ for i in range(1, 10):
+ res = self.call(NFSPROC4_COMPOUND, p.get_buffer())
+ un_p.reset(res)
+ res = un_p.unpack_COMPOUND4res()
+ if SHOW_TRAFFIC:
+ print(res)
+ un_p.done()
+ if res.status != NFS4ERR_DELAY:
+ break
+ time.sleep(1)

# Do some error checking

--
2.39.2