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authorAndy Adamson <andros@netapp.com>2014-09-29 12:31:57 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-30 09:35:11 -0700
commitf2368dcc930680343e06848cc09689f7b8e8a0b9 (patch)
tree812795fa65c58ef2ab96869cc86e509fdfcbc4a6 /fs/nfs
parentbb7105c3d5b128542239f2eff1e399e26959bcc7 (diff)
downloadlinux-linaro-stable-f2368dcc930680343e06848cc09689f7b8e8a0b9.tar.gz
NFSv4.1: Fix an NFSv4.1 state renewal regression
commit d1f456b0b9545f1606a54cd17c20775f159bd2ce upstream. Commit 2f60ea6b8ced ("NFSv4: The NFSv4.0 client must send RENEW calls if it holds a delegation") set the NFS4_RENEW_TIMEOUT flag in nfs4_renew_state, and does not put an nfs41_proc_async_sequence call, the NFSv4.1 lease renewal heartbeat call, on the wire to renew the NFSv4.1 state if the flag was not set. The NFS4_RENEW_TIMEOUT flag is set when "now" is after the last renewal (cl_last_renewal) plus the lease time divided by 3. This is arbitrary and sometimes does the following: In normal operation, the only way a future state renewal call is put on the wire is via a call to nfs4_schedule_state_renewal, which schedules a nfs4_renew_state workqueue task. nfs4_renew_state determines if the NFS4_RENEW_TIMEOUT should be set, and the calls nfs41_proc_async_sequence, which only gets sent if the NFS4_RENEW_TIMEOUT flag is set. Then the nfs41_proc_async_sequence rpc_release function schedules another state remewal via nfs4_schedule_state_renewal. Without this change we can get into a state where an application stops accessing the NFSv4.1 share, state renewal calls stop due to the NFS4_RENEW_TIMEOUT flag _not_ being set. The only way to recover from this situation is with a clientid re-establishment, once the application resumes and the server has timed out the lease and so returns NFS4ERR_BAD_SESSION on the subsequent SEQUENCE operation. An example application: open, lock, write a file. sleep for 6 * lease (could be less) ulock, close. In the above example with NFSv4.1 delegations enabled, without this change, there are no OP_SEQUENCE state renewal calls during the sleep, and the clientid is recovered due to lease expiration on the close. This issue does not occur with NFSv4.1 delegations disabled, nor with NFSv4.0, with or without delegations enabled. Signed-off-by: Andy Adamson <andros@netapp.com> Link: http://lkml.kernel.org/r/1411486536-23401-1-git-send-email-andros@netapp.com Fixes: 2f60ea6b8ced (NFSv4: The NFSv4.0 client must send RENEW calls...) Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/nfs4proc.c2
-rw-r--r--fs/nfs/nfs4renewd.c12
2 files changed, 11 insertions, 3 deletions
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 3fc87b6f9def..69fc437be661 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6067,7 +6067,7 @@ static int nfs41_proc_async_sequence(struct nfs_client *clp, struct rpc_cred *cr
int ret = 0;
if ((renew_flags & NFS4_RENEW_TIMEOUT) == 0)
- return 0;
+ return -EAGAIN;
task = _nfs41_proc_sequence(clp, cred, false);
if (IS_ERR(task))
ret = PTR_ERR(task);
diff --git a/fs/nfs/nfs4renewd.c b/fs/nfs/nfs4renewd.c
index 1720d32ffa54..e1ba58c3d1ad 100644
--- a/fs/nfs/nfs4renewd.c
+++ b/fs/nfs/nfs4renewd.c
@@ -88,10 +88,18 @@ nfs4_renew_state(struct work_struct *work)
}
nfs_expire_all_delegations(clp);
} else {
+ int ret;
+
/* Queue an asynchronous RENEW. */
- ops->sched_state_renewal(clp, cred, renew_flags);
+ ret = ops->sched_state_renewal(clp, cred, renew_flags);
put_rpccred(cred);
- goto out_exp;
+ switch (ret) {
+ default:
+ goto out_exp;
+ case -EAGAIN:
+ case -ENOMEM:
+ break;
+ }
}
} else {
dprintk("%s: failed to call renewd. Reason: lease not expired \n",