>>>>> "JBF" == J Bruce Fields <bfields@xxxxxxxxxxxx> writes: JBF> Those readdir changes were client-side, right? Based on that I'd JBF> been assuming a client bug, but maybe it'd be worth getting a full JBF> packet capture of the readdir reply to make sure it's legit. I have been working with bcodding on IRC for the past couple of days on this. Fortunately I was able to come up with way to fill up a directory in such a way that it will fail with certainty and as a bonus doesn't include any user data so I can feel OK about sharing packet captures. I have a capture alongside a kernel trace of the problematic operation in https://www.math.uh.edu/~tibbs/nfs/. Not that I can particularly tell anything useful from that, but bcodding says that it seems to point to some issue in sunrpc. And because I can easily reproduce this and I was able to do a bisect: 2c94b8eca1a26cd46010d6e73a23da5f2e93a19d is the first bad commit commit 2c94b8eca1a26cd46010d6e73a23da5f2e93a19d Author: Chuck Lever <chuck.lever@xxxxxxxxxx> Date: Mon Feb 11 11:25:41 2019 -0500 SUNRPC: Use au_rslack when computing reply buffer size au_rslack is significantly smaller than (au_cslack << 2). Using that value results in smaller receive buffers. In some cases this eliminates an extra segment in Reply chunks (RPC/RDMA). Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> :040000 040000 d4d1ce2fbe0035c5bd9df976b8c448df85dcb505 7011a792dfe72ff9cd70d66e45d353f3d7817e3e M net But of course, I can't say whether this is the actual bad commit or whether it just introduced a behavior change which alters the conditions under which the problem appears. And just to make sure that the blame doesn't lie with the old RHEL7 kernel, I rsynced over the problematic directory to a machine running something slightly more modern (5.1.11, which I know I need to update, but it's already set up to do kerberised NFS) and the same problem exists, though the directory listing does fail at a different place. - J<
