v4.19.13 snapshot.
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
new file mode 100644
index 0000000..d20b92f
--- /dev/null
+++ b/fs/lockd/clntproc.c
@@ -0,0 +1,862 @@
+/*
+ * linux/fs/lockd/clntproc.c
+ *
+ * RPC procedures for the client side NLM implementation
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.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>
+
+#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 *nlm_get_lockowner(struct nlm_lockowner *lockowner)
+{
+ refcount_inc(&lockowner->count);
+ return lockowner;
+}
+
+static void nlm_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 *__nlm_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 nlm_get_lockowner(lockowner);
+ }
+ return NULL;
+}
+
+static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
+{
+ struct nlm_lockowner *res, *new = NULL;
+
+ spin_lock(&host->h_lock);
+ res = __nlm_find_lockowner(host, owner);
+ if (res == NULL) {
+ spin_unlock(&host->h_lock);
+ new = kmalloc(sizeof(*new), GFP_KERNEL);
+ spin_lock(&host->h_lock);
+ res = __nlm_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(locks_inode(fl->fl_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.fl_type = fl->fl_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->fl_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(struct rpc_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(struct rpc_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->fl_file), req, NLMPROC_TEST);
+ if (status < 0)
+ goto out;
+
+ switch (req->a_res.status) {
+ case nlm_granted:
+ fl->fl_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->fl_type = req->a_res.lock.fl.fl_type;
+ fl->fl_pid = 0;
+ break;
+ default:
+ status = nlm_stat_to_errno(req->a_res.status);
+ }
+out:
+ 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 = nlm_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);
+ nlm_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 = nlm_find_lockowner(host, fl->fl_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->fl_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)
+{
+ struct rpc_cred *cred = nfs_file_cred(fl->fl_file);
+ struct nlm_host *host = req->a_host;
+ struct nlm_res *resp = &req->a_res;
+ struct nlm_wait *block = NULL;
+ unsigned char fl_flags = fl->fl_flags;
+ unsigned char fl_type;
+ int status = -ENOLCK;
+
+ if (nsm_monitor(host) < 0)
+ goto out;
+ req->a_args.state = nsm_local_state;
+
+ fl->fl_flags |= FL_ACCESS;
+ status = do_vfs_lock(fl);
+ fl->fl_flags = fl_flags;
+ if (status < 0)
+ goto out;
+
+ block = nlmclnt_prepare_block(host, fl);
+again:
+ /*
+ * Initialise resp->status to a valid non-zero value,
+ * since 0 == nlm_lck_granted
+ */
+ resp->status = nlm_lck_blocked;
+ 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_block(block, req, NLMCLNT_POLL_TIMEOUT);
+ if (status < 0)
+ break;
+ if (resp->status != nlm_lck_blocked)
+ break;
+ }
+
+ /* 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_unblock;
+ }
+
+ 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->fl_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->fl_flags = fl_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 && (fl_flags & FL_SLEEP))
+ status = -ENOLCK;
+ else
+ status = nlm_stat_to_errno(resp->status);
+out_unblock:
+ nlmclnt_finish_block(block);
+out:
+ nlmclnt_release_call(req);
+ return status;
+out_unlock:
+ /* Fatal error: ensure that we remove the lock altogether */
+ dprintk("lockd: lock attempt ended in fatal error.\n"
+ " Attempting to unlock.\n");
+ nlmclnt_finish_block(block);
+ fl_type = fl->fl_type;
+ fl->fl_type = F_UNLCK;
+ down_read(&host->h_rwsem);
+ do_vfs_lock(fl);
+ up_read(&host->h_rwsem);
+ fl->fl_type = fl_type;
+ fl->fl_flags = fl_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->fl_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->fl_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 fl_flags = fl->fl_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->fl_flags |= FL_EXISTS;
+ down_read(&host->h_rwsem);
+ status = do_vfs_lock(fl);
+ up_read(&host->h_rwsem);
+ fl->fl_flags = fl_flags;
+ if (status == -ENOENT) {
+ status = 0;
+ goto out;
+ }
+
+ refcount_inc(&req->a_count);
+ status = nlmclnt_async_call(nfs_file_cred(fl->fl_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:
+ 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_ASSASSINATED(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->fl_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_ASSASSINATED(task))
+ goto die;
+
+ if (task->tk_status < 0) {
+ dprintk("lockd: CANCEL call error %d, retrying.\n",
+ task->tk_status);
+ goto retry_cancel;
+ }
+
+ dprintk("lockd: cancel status %u (task %u)\n",
+ status, task->tk_pid);
+
+ 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;
+}