// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/lockd/clntproc.c
*
* RPC procedures for the client side NLM implementation
*
* Copyright (C) 1996, Olaf Kirch <[email protected]>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/filelock.h>
#include <linux/nfs_fs.h>
#include <linux/utsname.h>
#include <linux/freezer.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include "trace.h"
#define NLMDBG_FACILITY NLMDBG_CLIENT
#define NLMCLNT_GRACE_WAIT (5*HZ)
#define NLMCLNT_POLL_TIMEOUT (30*HZ)
#define NLMCLNT_MAX_RETRIES 3
static int nlmclnt_test(struct nlm_rqst *, struct file_lock *);
static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *);
static int nlm_stat_to_errno(__be32 stat);
static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *);
static const struct rpc_call_ops nlmclnt_unlock_ops;
static const struct rpc_call_ops nlmclnt_cancel_ops;
/*
* Cookie counter for NLM requests
*/
static atomic_t nlm_cookie = ATOMIC_INIT(0x1234);
void nlmclnt_next_cookie(struct nlm_cookie *c)
{
u32 cookie = atomic_inc_return(&nlm_cookie);
memcpy(c->data, &cookie, 4);
c->len=4;
}
static struct nlm_lockowner *
nlmclnt_get_lockowner(struct nlm_lockowner *lockowner)
{
refcount_inc(&lockowner->count);
return lockowner;
}
static void nlmclnt_put_lockowner(struct nlm_lockowner *lockowner)
{
if (!refcount_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
return;
list_del(&lockowner->list);
spin_unlock(&lockowner->host->h_lock);
nlmclnt_release_host(lockowner->host);
kfree(lockowner);
}
static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
{
struct nlm_lockowner *lockowner;
list_for_each_entry(lockowner, &host->h_lockowners, list) {
if (lockowner->pid == pid)
return -EBUSY;
}
return 0;
}
static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
{
uint32_t res;
do {
res = host->h_pidcount++;
} while (nlm_pidbusy(host, res) < 0);
return res;
}
static struct nlm_lockowner *__nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner)
{
struct nlm_lockowner *lockowner;
list_for_each_entry(lockowner, &host->h_lockowners, list) {
if (lockowner->owner != owner)
continue;
return nlmclnt_get_lockowner(lockowner);
}
return NULL;
}
static struct nlm_lockowner *nlmclnt_find_lockowner(struct nlm_host *host, fl_owner_t owner)
{
struct nlm_lockowner *res, *new = NULL;
spin_lock(&host->h_lock);
res = __nlmclnt_find_lockowner(host, owner);
if (res == NULL) {
spin_unlock(&host->h_lock);
new = kmalloc(sizeof(*new), GFP_KERNEL);
spin_lock(&host->h_lock);
res = __nlmclnt_find_lockowner(host, owner);
if (res == NULL && new != NULL) {
res = new;
refcount_set(&new->count, 1);
new->owner = owner;
new->pid = __nlm_alloc_pid(host);
new->host = nlm_get_host(host);
list_add(&new->list, &host->h_lockowners);
new = NULL;
}
}
spin_unlock(&host->h_lock);
kfree(new);
return res;
}
/*
* Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
*/
static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
{
struct nlm_args *argp = &req->a_args;
struct nlm_lock *lock = &argp->lock;
char *nodename = req->a_host->h_rpcclnt->cl_nodename;
nlmclnt_next_cookie(&argp->cookie);
memcpy(&lock->fh, NFS_FH(file_inode(fl->c.flc_file)),
sizeof(struct nfs_fh));
lock->caller = nodename;
lock->oh.data = req->a_owner;
lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s",
(unsigned int)fl->fl_u.nfs_fl.owner->pid,
nodename);
lock->svid = fl->fl_u.nfs_fl.owner->pid;
lock->fl.fl_start = fl->fl_start;
lock->fl.fl_end = fl->fl_end;
lock->fl.c.flc_type = fl->c.flc_type;
}
static void nlmclnt_release_lockargs(struct nlm_rqst *req)
{
WARN_ON_ONCE(req->a_args.lock.fl.fl_ops != NULL);
}
/**
* nlmclnt_proc - Perform a single client-side lock request
* @host: address of a valid nlm_host context representing the NLM server
* @cmd: fcntl-style file lock operation to perform
* @fl: address of arguments for the lock operation
* @data: address of data to be sent to callback operations
*
*/
int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl, void *data)
{
struct nlm_rqst *call;
int status;
const struct nlmclnt_operations *nlmclnt_ops = host->h_nlmclnt_ops;
call = nlm_alloc_call(host);
if (call == NULL)
return -ENOMEM;
if (nlmclnt_ops && nlmclnt_ops->nlmclnt_alloc_call)
nlmclnt_ops->nlmclnt_alloc_call(data);
nlmclnt_locks_init_private(fl, host);
if (!fl->fl_u.nfs_fl.owner) {
/* lockowner allocation has failed */
nlmclnt_release_call(call);
return -ENOMEM;
}
/* Set up the argument struct */
nlmclnt_setlockargs(call, fl);
call->a_callback_data = data;
if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
if (fl->c.flc_type != F_UNLCK) {
call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
status = nlmclnt_lock(call, fl);
} else
status = nlmclnt_unlock(call, fl);
} else if (IS_GETLK(cmd))
status = nlmclnt_test(call, fl);
else
status = -EINVAL;
fl->fl_ops->fl_release_private(fl);
fl->fl_ops = NULL;
dprintk("lockd: clnt proc returns %d\n", status);
return status;
}
EXPORT_SYMBOL_GPL(nlmclnt_proc);
/*
* Allocate an NLM RPC call struct
*/
struct nlm_rqst *nlm_alloc_call(struct nlm_host *host)
{
struct nlm_rqst *call;
for(;;) {
call = kzalloc(sizeof(*call), GFP_KERNEL);
if (call != NULL) {
refcount_set(&call->a_count, 1);
locks_init_lock(&call->a_args.lock.fl);
locks_init_lock(&call->a_res.lock.fl);
call->a_host = nlm_get_host(host);
return call;
}
if (signalled())
break;
printk("nlm_alloc_call: failed, waiting for memory\n");
schedule_timeout_interruptible(5*HZ);
}
return NULL;
}
void nlmclnt_release_call(struct nlm_rqst *call)
{
const struct nlmclnt_operations *nlmclnt_ops = call->a_host->h_nlmclnt_ops;
if (!refcount_dec_and_test(&call->a_count))
return;
if (nlmclnt_ops && nlmclnt_ops->nlmclnt_release_call)
nlmclnt_ops->nlmclnt_release_call(call->a_callback_data);
nlmclnt_release_host(call->a_host);
nlmclnt_release_lockargs(call);
kfree(call);
}
static void nlmclnt_rpc_release(void *data)
{
nlmclnt_release_call(data);
}
static int nlm_wait_on_grace(wait_queue_head_t *queue)
{
DEFINE_WAIT(wait);
int status = -EINTR;
prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
if (!signalled ()) {
schedule_timeout(NLMCLNT_GRACE_WAIT);
try_to_freeze();
if (!signalled ())
status = 0;
}
finish_wait(queue, &wait);
return status;
}
/*
* Generic NLM call
*/
static int
nlmclnt_call(const struct cred *cred, struct nlm_rqst *req, u32 proc)
{
struct nlm_host *host = req->a_host;
struct rpc_clnt *clnt;
struct nlm_args *argp = &req->a_args;
struct nlm_res *resp = &req->a_res;
struct rpc_message msg = {
.rpc_argp = argp,
.rpc_resp = resp,
.rpc_cred = cred,
};
int status;
dprintk("lockd: call procedure %d on %s\n",
(int)proc, host->h_name);
do {
if (host->h_reclaiming && !argp->reclaim)
goto in_grace_period;
/* If we have no RPC client yet, create one. */
if ((clnt = nlm_bind_host(host)) == NULL)
return -ENOLCK;
msg.rpc_proc = &clnt->cl_procinfo[proc];
/* Perform the RPC call. If an error occurs, try again */
if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
dprintk("lockd: rpc_call returned error %d\n", -status);
switch (status) {
case -EPROTONOSUPPORT:
status = -EINVAL;
break;
case -ECONNREFUSED:
case -ETIMEDOUT:
case -ENOTCONN:
nlm_rebind_host(host);
status = -EAGAIN;
break;
case -ERESTARTSYS:
return signalled () ? -EINTR : status;
default:
break;
}
break;
} else
if (resp->status == nlm_lck_denied_grace_period) {
dprintk("lockd: server in grace period\n");
if (argp->reclaim) {
printk(KERN_WARNING
"lockd: spurious grace period reject?!\n");
return -ENOLCK;
}
} else {
if (!argp->reclaim) {
/* We appear to be out of the grace period */
wake_up_all(&host->h_gracewait);
}
dprintk("lockd: server returns status %d\n",
ntohl(resp->status));
return 0; /* Okay, call complete */
}
in_grace_period:
/*
* The server has rebooted and appears to be in the grace
* period during which locks are only allowed to be
* reclaimed.
* We can only back off and try again later.
*/
status = nlm_wait_on_grace(&host->h_gracewait);
} while (status == 0);
return status;
}
/*
* Generic NLM call, async version.
*/
static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
{
struct nlm_host *host = req->a_host;
struct rpc_clnt *clnt;
struct rpc_task_setup task_setup_data = {
.rpc_message = msg,
.callback_ops = tk_ops,
.callback_data = req,
.flags = RPC_TASK_ASYNC,
};
dprintk("lockd: call procedure %d on %s (async)\n",
(int)proc, host->h_name);
/* If we have no RPC client yet, create one. */
clnt = nlm_bind_host(host);
if (clnt == NULL)
goto out_err;
msg->rpc_proc = &clnt->cl_procinfo[proc];
task_setup_data.rpc_client = clnt;
/* bootstrap and kick off the async RPC call */
return rpc_run_task(&task_setup_data);
out_err:
tk_ops->rpc_release(req);
return ERR_PTR(-ENOLCK);
}
static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
{
struct rpc_task *task;
task = __nlm_async_call(req, proc, msg, tk_ops);
if (IS_ERR(task))
return PTR_ERR(task);
rpc_put_task(task);
return 0;
}
/*
* NLM asynchronous call.
*/
int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
{
struct rpc_message msg = {
.rpc_argp = &req->a_args,
.rpc_resp = &req->a_res,
};
return nlm_do_async_call(req, proc, &msg, tk_ops);
}
int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
{
struct rpc_message msg = {
.rpc_argp = &req->a_res,
};
return nlm_do_async_call(req, proc, &msg, tk_ops);
}
/*
* NLM client asynchronous call.
*
* Note that although the calls are asynchronous, and are therefore
* guaranteed to complete, we still always attempt to wait for
* completion in order to be able to correctly track the lock
* state.
*/
static int nlmclnt_async_call(const struct cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
{
struct rpc_message msg = {
.rpc_argp = &req->a_args,
.rpc_resp = &req->a_res,
.rpc_cred = cred,
};
struct rpc_task *task;
int err;
task = __nlm_async_call(req, proc, &msg, tk_ops);
if (IS_ERR(task))
return PTR_ERR(task);
err = rpc_wait_for_completion_task(task);
rpc_put_task(task);
return err;
}
/*
* TEST for the presence of a conflicting lock
*/
static int
nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
{
int status;
status = nlmclnt_call(nfs_file_cred(fl->c.flc_file), req,
NLMPROC_TEST);
if (status < 0)
goto out;
switch (req->a_res.status) {
case nlm_granted:
fl->c.flc_type = F_UNLCK;
break;
case nlm_lck_denied:
/*
* Report the conflicting lock back to the application.
*/
fl->fl_start = req->a_res.lock.fl.fl_start;
fl->fl_end = req->a_res.lock.fl.fl_end;
fl->c.flc_type = req->a_res.lock.fl.c.flc_type;
fl->c.flc_pid = -req->a_res.lock.fl.c.flc_pid;
break;
default:
status = nlm_stat_to_errno(req->a_res.status);
}
out:
trace_nlmclnt_test(&req->a_args.lock,
(const struct sockaddr *)&req->a_host->h_addr,
req->a_host->h_addrlen, req->a_res.status);
nlmclnt_release_call(req);
return status;
}
static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
new->fl_u.nfs_fl.owner = nlmclnt_get_lockowner(fl->fl_u.nfs_fl.owner);
list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
}
static void nlmclnt_locks_release_private(struct file_lock *fl)
{
spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock);
list_del(&fl->fl_u.nfs_fl.list);
spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock);
nlmclnt_put_lockowner(fl->fl_u.nfs_fl.owner);
}
static const struct file_lock_operations nlmclnt_lock_ops = {
.fl_copy_lock = nlmclnt_locks_copy_lock,
.fl_release_private = nlmclnt_locks_release_private,
};
static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
{
fl->fl_u.nfs_fl.state = 0;
fl->fl_u.nfs_fl.owner = nlmclnt_find_lockowner(host,
fl->c.flc_owner);
INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
fl->fl_ops = &nlmclnt_lock_ops;
}
static int do_vfs_lock(struct file_lock *fl)
{
return locks_lock_file_wait(fl->c.flc_file, fl);
}
/*
* LOCK: Try to create a lock
*
* Programmer Harassment Alert
*
* When given a blocking lock request in a sync RPC call, the HPUX lockd
* will faithfully return LCK_BLOCKED but never cares to notify us when
* the lock could be granted. This way, our local process could hang
* around forever waiting for the callback.
*
* Solution A: Implement busy-waiting
* Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
*
* For now I am implementing solution A, because I hate the idea of
* re-implementing lockd for a third time in two months. The async
* calls shouldn't be too hard to do, however.
*
* This is one of the lovely things about standards in the NFS area:
* they're so soft and squishy you can't really blame HP for doing this.
*/
static int
nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
{
const struct cred *cred = nfs_file_cred(fl->c.flc_file);
struct nlm_host *host = req->a_host;
struct nlm_res *resp = &req->a_res;
struct nlm_wait block;
unsigned char flags = fl->c.flc_flags;
unsigned char type;
__be32 b_status;
int status = -ENOLCK;
if (nsm_monitor(host) < 0)
goto out;
req->a_args.state = nsm_local_state;
fl->c.flc_flags |= FL_ACCESS;
status = do_vfs_lock(fl);
fl->c.flc_flags = flags;
if (status < 0)
goto out;
nlmclnt_prepare_block(&block, host, fl);
again:
/*
* Initialise resp->status to a valid non-zero value,
* since 0 == nlm_lck_granted
*/
resp->status = nlm_lck_blocked;
/*
* A GRANTED callback can come at any time -- even before the reply
* to the LOCK request arrives, so we queue the wait before
* requesting the lock.
*/
nlmclnt_queue_block(&block);
for (;;) {
/* Reboot protection */
fl->fl_u.nfs_fl.state = host->h_state;
status = nlmclnt_call(cred, req, NLMPROC_LOCK);
if (status < 0)
break;
/* Did a reclaimer thread notify us of a server reboot? */
if (resp->status == nlm_lck_denied_grace_period)
continue;
if (resp->status != nlm_lck_blocked)
break;
/* Wait on an NLM blocking lock */
status = nlmclnt_wait(&block, req, NLMCLNT_POLL_TIMEOUT);
if (status < 0)
break;
if (block.b_status != nlm_lck_blocked)
break;
}
b_status = nlmclnt_dequeue_block(&block);
if (resp->status == nlm_lck_blocked)
resp->status = b_status;
/* if we were interrupted while blocking, then cancel the lock request
* and exit
*/
if (resp->status == nlm_lck_blocked) {
if (!req->a_args.block)
goto out_unlock;
if (nlmclnt_cancel(host, req->a_args.block, fl) == 0)
goto out;
}
if (resp->status == nlm_granted) {
down_read(&host->h_rwsem);
/* Check whether or not the server has rebooted */
if (fl->fl_u.nfs_fl.state != host->h_state) {
up_read(&host->h_rwsem);
goto again;
}
/* Ensure the resulting lock will get added to granted list */
fl->c.flc_flags |= FL_SLEEP;
if (do_vfs_lock(fl) < 0)
printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", __func__);
up_read(&host->h_rwsem);
fl->c.flc_flags = flags;
status = 0;
}
if (status < 0)
goto out_unlock;
/*
* EAGAIN doesn't make sense for sleeping locks, and in some
* cases NLM_LCK_DENIED is returned for a permanent error. So
* turn it into an ENOLCK.
*/
if (resp->status == nlm_lck_denied && (flags & FL_SLEEP))
status = -ENOLCK;
else
status = nlm_stat_to_errno(resp->status);
out:
trace_nlmclnt_lock(&req->a_args.lock,
(const struct sockaddr *)&req->a_host->h_addr,
req->a_host->h_addrlen, req->a_res.status);
nlmclnt_release_call(req);
return status;
out_unlock:
/* Fatal error: ensure that we remove the lock altogether */
trace_nlmclnt_lock(&req->a_args.lock,
(const struct sockaddr *)&req->a_host->h_addr,
req->a_host->h_addrlen, req->a_res.status);
dprintk("lockd: lock attempt ended in fatal error.\n"
" Attempting to unlock.\n");
type = fl->c.flc_type;
fl->c.flc_type = F_UNLCK;
down_read(&host->h_rwsem);
do_vfs_lock(fl);
up_read(&host->h_rwsem);
fl->c.flc_type = type;
fl->c.flc_flags = flags;
nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
return status;
}
/*
* RECLAIM: Try to reclaim a lock
*/
int
nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl,
struct nlm_rqst *req)
{
int status;
memset(req, 0, sizeof(*req));
locks_init_lock(&req->a_args.lock.fl);
locks_init_lock(&req->a_res.lock.fl);
req->a_host = host;
/* Set up the argument struct */
nlmclnt_setlockargs(req, fl);
req->a_args.reclaim = 1;
status = nlmclnt_call(nfs_file_cred(fl->c.flc_file), req,
NLMPROC_LOCK);
if (status >= 0 && req->a_res.status == nlm_granted)
return 0;
printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
"(errno %d, status %d)\n",
fl->c.flc_pid,
status, ntohl(req->a_res.status));
/*
* FIXME: This is a serious failure. We can
*
* a. Ignore the problem
* b. Send the owning process some signal (Linux doesn't have
* SIGLOST, though...)
* c. Retry the operation
*
* Until someone comes up with a simple implementation
* for b or c, I'll choose option a.
*/
return -ENOLCK;
}
/*
* UNLOCK: remove an existing lock
*/
static int
nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
{
struct nlm_host *host = req->a_host;
struct nlm_res *resp = &req->a_res;
int status;
unsigned char flags = fl->c.flc_flags;
/*
* Note: the server is supposed to either grant us the unlock
* request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either
* case, we want to unlock.
*/
fl->c.flc_flags |= FL_EXISTS;
down_read(&host->h_rwsem);
status = do_vfs_lock(fl);
up_read(&host->h_rwsem);
fl->c.flc_flags = flags;
if (status == -ENOENT) {
status = 0;
goto out;
}
refcount_inc(&req->a_count);
status = nlmclnt_async_call(nfs_file_cred(fl->c.flc_file), req,
NLMPROC_UNLOCK, &nlmclnt_unlock_ops);
if (status < 0)
goto out;
if (resp->status == nlm_granted)
goto out;
if (resp->status != nlm_lck_denied_nolocks)
printk("lockd: unexpected unlock status: %d\n",
ntohl(resp->status));
/* What to do now? I'm out of my depth... */
status = -ENOLCK;
out:
trace_nlmclnt_unlock(&req->a_args.lock,
(const struct sockaddr *)&req->a_host->h_addr,
req->a_host->h_addrlen, req->a_res.status);
nlmclnt_release_call(req);
return status;
}
static void nlmclnt_unlock_prepare(struct rpc_task *task, void *data)
{
struct nlm_rqst *req = data;
const struct nlmclnt_operations *nlmclnt_ops = req->a_host->h_nlmclnt_ops;
bool defer_call = false;
if (nlmclnt_ops && nlmclnt_ops->nlmclnt_unlock_prepare)
defer_call = nlmclnt_ops->nlmclnt_unlock_prepare(task, req->a_callback_data);
if (!defer_call)
rpc_call_start(task);
}
static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
{
struct nlm_rqst *req = data;
u32 status = ntohl(req->a_res.status);
if (RPC_SIGNALLED(task))
goto die;
if (task->tk_status < 0) {
dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
switch (task->tk_status) {
case -EACCES:
case -EIO:
goto die;
default:
goto retry_rebind;
}
}
if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
rpc_delay(task, NLMCLNT_GRACE_WAIT);
goto retry_unlock;
}
if (status != NLM_LCK_GRANTED)
printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
die:
return;
retry_rebind:
nlm_rebind_host(req->a_host);
retry_unlock:
rpc_restart_call(task);
}
static const struct rpc_call_ops nlmclnt_unlock_ops = {
.rpc_call_prepare = nlmclnt_unlock_prepare,
.rpc_call_done = nlmclnt_unlock_callback,
.rpc_release = nlmclnt_rpc_release,
};
/*
* Cancel a blocked lock request.
* We always use an async RPC call for this in order not to hang a
* process that has been Ctrl-C'ed.
*/
static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl)
{
struct nlm_rqst *req;
int status;
dprintk("lockd: blocking lock attempt was interrupted by a signal.\n"
" Attempting to cancel lock.\n");
req = nlm_alloc_call(host);
if (!req)
return -ENOMEM;
req->a_flags = RPC_TASK_ASYNC;
nlmclnt_setlockargs(req, fl);
req->a_args.block = block;
refcount_inc(&req->a_count);
status = nlmclnt_async_call(nfs_file_cred(fl->c.flc_file), req,
NLMPROC_CANCEL, &nlmclnt_cancel_ops);
if (status == 0 && req->a_res.status == nlm_lck_denied)
status = -ENOLCK;
nlmclnt_release_call(req);
return status;
}
static void nlmclnt_cancel_callback(struct rpc_task *task, void *data)
{
struct nlm_rqst *req = data;
u32 status = ntohl(req->a_res.status);
if (RPC_SIGNALLED(task))
goto die;
if (task->tk_status < 0) {
dprintk("lockd: CANCEL call error %d, retrying.\n",
task->tk_status);
goto retry_cancel;
}
switch (status) {
case NLM_LCK_GRANTED:
case NLM_LCK_DENIED_GRACE_PERIOD:
case NLM_LCK_DENIED:
/* Everything's good */
break;
case NLM_LCK_DENIED_NOLOCKS:
dprintk("lockd: CANCEL failed (server has no locks)\n");
goto retry_cancel;
default:
printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
status);
}
die:
return;
retry_cancel:
/* Don't ever retry more than 3 times */
if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
goto die;
nlm_rebind_host(req->a_host);
rpc_restart_call(task);
rpc_delay(task, 30 * HZ);
}
static const struct rpc_call_ops nlmclnt_cancel_ops = {
.rpc_call_done = nlmclnt_cancel_callback,
.rpc_release = nlmclnt_rpc_release,
};
/*
* Convert an NLM status code to a generic kernel errno
*/
static int
nlm_stat_to_errno(__be32 status)
{
switch(ntohl(status)) {
case NLM_LCK_GRANTED:
return 0;
case NLM_LCK_DENIED:
return -EAGAIN;
case NLM_LCK_DENIED_NOLOCKS:
case NLM_LCK_DENIED_GRACE_PERIOD:
return -ENOLCK;
case NLM_LCK_BLOCKED:
printk(KERN_NOTICE "lockd: unexpected status NLM_BLOCKED\n");
return -ENOLCK;
#ifdef CONFIG_LOCKD_V4
case NLM_DEADLCK:
return -EDEADLK;
case NLM_ROFS:
return -EROFS;
case NLM_STALE_FH:
return -ESTALE;
case NLM_FBIG:
return -EOVERFLOW;
case NLM_FAILED:
return -ENOLCK;
#endif
}
printk(KERN_NOTICE "lockd: unexpected server status %d\n",
ntohl(status));
return -ENOLCK;
}
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