linux/fs/nfs/nfs4renewd.c

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/*
* fs/nfs/nfs4renewd.c
*
* Copyright (c) 2002 The Regents of the University of Michigan.
* All rights reserved.
*
* Kendrick Smith <kmsmith@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Implementation of the NFSv4 "renew daemon", which wakes up periodically to
* send a RENEW, to keep state alive on the server. The daemon is implemented
* as an rpc_task, not a real kernel thread, so it always runs in rpciod's
* context. There is one renewd per nfs_server.
*
*/
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include "nfs4_fs.h"
#include "delegation.h"
#define NFSDBG_FACILITY NFSDBG_STATE
void
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nfs4_renew_state(struct work_struct *work)
{
const struct nfs4_state_maintenance_ops *ops;
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struct nfs_client *clp =
container_of(work, struct nfs_client, cl_renewd.work);
struct rpc_cred *cred;
long lease;
unsigned long last, now;
unsigned renew_flags = 0;
ops = clp->cl_mvops->state_renewal_ops;
dprintk("%s: start\n", __func__);
if (test_bit(NFS_CS_STOP_RENEW, &clp->cl_res_state))
goto out;
spin_lock(&clp->cl_lock);
lease = clp->cl_lease_time;
last = clp->cl_last_renewal;
now = jiffies;
/* Are we close to a lease timeout? */
if (time_after(now, last + lease/3))
renew_flags |= NFS4_RENEW_TIMEOUT;
if (nfs_delegations_present(clp))
renew_flags |= NFS4_RENEW_DELEGATION_CB;
if (renew_flags != 0) {
cred = ops->get_state_renewal_cred_locked(clp);
spin_unlock(&clp->cl_lock);
if (cred == NULL) {
if (!(renew_flags & NFS4_RENEW_DELEGATION_CB)) {
set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
goto out;
}
nfs_expire_all_delegations(clp);
} else {
NFSv4.1: Fix an NFSv4.1 state renewal regression 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...) Cc: stable@vger.kernel.org # 3.2.x Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-29 16:31:57 +00:00
int ret;
/* Queue an asynchronous RENEW. */
NFSv4.1: Fix an NFSv4.1 state renewal regression 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...) Cc: stable@vger.kernel.org # 3.2.x Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-29 16:31:57 +00:00
ret = ops->sched_state_renewal(clp, cred, renew_flags);
put_rpccred(cred);
NFSv4.1: Fix an NFSv4.1 state renewal regression 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...) Cc: stable@vger.kernel.org # 3.2.x Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-29 16:31:57 +00:00
switch (ret) {
default:
goto out_exp;
case -EAGAIN:
case -ENOMEM:
break;
}
}
} else {
dprintk("%s: failed to call renewd. Reason: lease not expired \n",
__func__);
spin_unlock(&clp->cl_lock);
}
nfs4_schedule_state_renewal(clp);
out_exp:
nfs_expire_unreferenced_delegations(clp);
out:
dprintk("%s: done\n", __func__);
}
void
nfs4_schedule_state_renewal(struct nfs_client *clp)
{
long timeout;
spin_lock(&clp->cl_lock);
timeout = (2 * clp->cl_lease_time) / 3 + (long)clp->cl_last_renewal
- (long)jiffies;
if (timeout < 5 * HZ)
timeout = 5 * HZ;
dprintk("%s: requeueing work. Lease period = %ld\n",
__func__, (timeout + HZ - 1) / HZ);
workqueue: use mod_delayed_work() instead of cancel + queue Convert delayed_work users doing cancel_delayed_work() followed by queue_delayed_work() to mod_delayed_work(). Most conversions are straight-forward. Ones worth mentioning are, * drivers/edac/edac_mc.c: edac_mc_workq_setup() converted to always use mod_delayed_work() and cancel loop in edac_mc_reset_delay_period() is dropped. * drivers/platform/x86/thinkpad_acpi.c: No need to remember whether watchdog is active or not. @fan_watchdog_active and related code dropped. * drivers/power/charger-manager.c: Seemingly a lot of delayed_work_pending() abuse going on here. [delayed_]work_pending() are unsynchronized and racy when used like this. I converted one instance in fullbatt_handler(). Please conver the rest so that it invokes workqueue APIs for the intended target state rather than trying to game work item pending state transitions. e.g. if timer should be modified - call mod_delayed_work(), canceled - call cancel_delayed_work[_sync](). * drivers/thermal/thermal_sys.c: thermal_zone_device_set_polling() simplified. Note that round_jiffies() calls in this function are meaningless. round_jiffies() work on absolute jiffies not delta delay used by delayed_work. v2: Tomi pointed out that __cancel_delayed_work() users can't be safely converted to mod_delayed_work(). They could be calling it from irq context and if that happens while delayed_work_timer_fn() is running, it could deadlock. __cancel_delayed_work() users are dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Anton Vorontsov <cbouatmailru@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Doug Thompson <dougthompson@xmission.com> Cc: David Airlie <airlied@linux.ie> Cc: Roland Dreier <roland@kernel.org> Cc: "John W. Linville" <linville@tuxdriver.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <len.brown@intel.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Johannes Berg <johannes@sipsolutions.net>
2012-08-03 17:30:47 +00:00
mod_delayed_work(system_wq, &clp->cl_renewd, timeout);
set_bit(NFS_CS_RENEWD, &clp->cl_res_state);
spin_unlock(&clp->cl_lock);
}
void
nfs4_kill_renewd(struct nfs_client *clp)
{
cancel_delayed_work_sync(&clp->cl_renewd);
}
/*
* Local variables:
* c-basic-offset: 8
* End:
*/