Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 820 insertions, 0 deletions

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
new file mode 100644
index 000000000000..a4407619b1f1
--- /dev/null
+++ b/fs/lockd/clntproc.c
@@ -0,0 +1,820 @@
+/*
+ * linux/fs/lockd/clntproc.c
+ *
+ * RPC procedures for the client side NLM implementation
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/nfs_fs.h>
+#include <linux/utsname.h>
+#include <linux/smp_lock.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svc.h>
+#include <linux/lockd/lockd.h>
+#include <linux/lockd/sm_inter.h>
+
+#define NLMDBG_FACILITY         NLMDBG_CLIENT
+#define NLMCLNT_GRACE_WAIT      (5*HZ)
+
+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 void     nlmclnt_unlock_callback(struct rpc_task *);
+static void     nlmclnt_cancel_callback(struct rpc_task *);
+static int      nlm_stat_to_errno(u32 stat);
+static void     nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host);
+
+/*
+ * Cookie counter for NLM requests
+ */
+static u32      nlm_cookie = 0x1234;
+
+static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
+{
+        memcpy(c->data, &nlm_cookie, 4);
+        memset(c->data+4, 0, 4);
+        c->len=4;
+        nlm_cookie++;
+}
+
+static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
+{
+        atomic_inc(&lockowner->count);
+        return lockowner;
+}
+
+static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
+{
+        if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
+                return;
+        list_del(&lockowner->list);
+        spin_unlock(&lockowner->host->h_lock);
+        nlm_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 = (struct nlm_lockowner *)kmalloc(sizeof(*new), GFP_KERNEL);
+                spin_lock(&host->h_lock);
+                res = __nlm_find_lockowner(host, owner);
+                if (res == NULL && new != NULL) {
+                        res = new;
+                        atomic_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);
+        if (new != NULL)
+                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;
+
+        nlmclnt_next_cookie(&argp->cookie);
+        argp->state   = nsm_local_state;
+        memcpy(&lock->fh, NFS_FH(fl->fl_file->f_dentry->d_inode), sizeof(struct nfs_fh));
+        lock->caller  = system_utsname.nodename;
+        lock->oh.data = req->a_owner;
+        lock->oh.len  = sprintf(req->a_owner, "%d@%s",
+                                current->pid, system_utsname.nodename);
+        locks_copy_lock(&lock->fl, fl);
+}
+
+static void nlmclnt_release_lockargs(struct nlm_rqst *req)
+{
+        struct file_lock *fl = &req->a_args.lock.fl;
+
+        if (fl->fl_ops && fl->fl_ops->fl_release_private)
+                fl->fl_ops->fl_release_private(fl);
+}
+
+/*
+ * Initialize arguments for GRANTED call. The nlm_rqst structure
+ * has been cleared already.
+ */
+int
+nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
+{
+        locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
+        memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
+        call->a_args.lock.caller = system_utsname.nodename;
+        call->a_args.lock.oh.len = lock->oh.len;
+
+        /* set default data area */
+        call->a_args.lock.oh.data = call->a_owner;
+
+        if (lock->oh.len > NLMCLNT_OHSIZE) {
+                void *data = kmalloc(lock->oh.len, GFP_KERNEL);
+                if (!data) {
+                        nlmclnt_freegrantargs(call);
+                        return 0;
+                }
+                call->a_args.lock.oh.data = (u8 *) data;
+        }
+
+        memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
+        return 1;
+}
+
+void
+nlmclnt_freegrantargs(struct nlm_rqst *call)
+{
+        struct file_lock *fl = &call->a_args.lock.fl;
+        /*
+         * Check whether we allocated memory for the owner.
+         */
+        if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
+                kfree(call->a_args.lock.oh.data);
+        }
+        if (fl->fl_ops && fl->fl_ops->fl_release_private)
+                fl->fl_ops->fl_release_private(fl);
+}
+
+/*
+ * This is the main entry point for the NLM client.
+ */
+int
+nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
+{
+        struct nfs_server       *nfssrv = NFS_SERVER(inode);
+        struct nlm_host         *host;
+        struct nlm_rqst         reqst, *call = &reqst;
+        sigset_t                oldset;
+        unsigned long           flags;
+        int                     status, proto, vers;
+
+        vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
+        if (NFS_PROTO(inode)->version > 3) {
+                printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
+                return -ENOLCK;
+        }
+
+        /* Retrieve transport protocol from NFS client */
+        proto = NFS_CLIENT(inode)->cl_xprt->prot;
+
+        if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
+                return -ENOLCK;
+
+        /* Create RPC client handle if not there, and copy soft
+         * and intr flags from NFS client. */
+        if (host->h_rpcclnt == NULL) {
+                struct rpc_clnt *clnt;
+
+                /* Bind an rpc client to this host handle (does not
+                 * perform a portmapper lookup) */
+                if (!(clnt = nlm_bind_host(host))) {
+                        status = -ENOLCK;
+                        goto done;
+                }
+                clnt->cl_softrtry = nfssrv->client->cl_softrtry;
+                clnt->cl_intr     = nfssrv->client->cl_intr;
+                clnt->cl_chatty   = nfssrv->client->cl_chatty;
+        }
+
+        /* Keep the old signal mask */
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        oldset = current->blocked;
+
+        /* If we're cleaning up locks because the process is exiting,
+         * perform the RPC call asynchronously. */
+        if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
+            && fl->fl_type == F_UNLCK
+            && (current->flags & PF_EXITING)) {
+                sigfillset(&current->blocked);  /* Mask all signals */
+                recalc_sigpending();
+                spin_unlock_irqrestore(&current->sighand->siglock, flags);
+
+                call = nlmclnt_alloc_call();
+                if (!call) {
+                        status = -ENOMEM;
+                        goto out_restore;
+                }
+                call->a_flags = RPC_TASK_ASYNC;
+        } else {
+                spin_unlock_irqrestore(&current->sighand->siglock, flags);
+                memset(call, 0, sizeof(*call));
+                locks_init_lock(&call->a_args.lock.fl);
+                locks_init_lock(&call->a_res.lock.fl);
+        }
+        call->a_host = host;
+
+        nlmclnt_locks_init_private(fl, host);
+
+        /* Set up the argument struct */
+        nlmclnt_setlockargs(call, fl);
+
+        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;
+
+ out_restore:
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        current->blocked = oldset;
+        recalc_sigpending();
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
+
+done:
+        dprintk("lockd: clnt proc returns %d\n", status);
+        nlm_release_host(host);
+        return status;
+}
+EXPORT_SYMBOL(nlmclnt_proc);
+
+/*
+ * Allocate an NLM RPC call struct
+ */
+struct nlm_rqst *
+nlmclnt_alloc_call(void)
+{
+        struct nlm_rqst *call;
+
+        while (!signalled()) {
+                call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
+                if (call) {
+                        memset(call, 0, sizeof(*call));
+                        locks_init_lock(&call->a_args.lock.fl);
+                        locks_init_lock(&call->a_res.lock.fl);
+                        return call;
+                }
+                printk("nlmclnt_alloc_call: failed, waiting for memory\n");
+                current->state = TASK_INTERRUPTIBLE;
+                schedule_timeout(5*HZ);
+        }
+        return NULL;
+}
+
+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(PF_FREEZE);
+                if (!signalled ())
+                        status = 0;
+        }
+        finish_wait(queue, &wait);
+        return status;
+}
+
+/*
+ * Generic NLM call
+ */
+static int
+nlmclnt_call(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,
+        };
+        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", 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.
+ */
+int
+nlmsvc_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
+{
+        struct nlm_host *host = req->a_host;
+        struct rpc_clnt *clnt;
+        struct rpc_message msg = {
+                .rpc_argp       = &req->a_args,
+                .rpc_resp       = &req->a_res,
+        };
+        int             status;
+
+        dprintk("lockd: call procedure %d on %s (async)\n",
+                        (int)proc, host->h_name);
+
+        /* 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];
+
+        /* bootstrap and kick off the async RPC call */
+        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
+
+        return status;
+}
+
+static int
+nlmclnt_async_call(struct nlm_rqst *req, u32 proc, rpc_action callback)
+{
+        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,
+        };
+        int             status;
+
+        dprintk("lockd: call procedure %d on %s (async)\n",
+                        (int)proc, host->h_name);
+
+        /* 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];
+
+        /* Increment host refcount */
+        nlm_get_host(host);
+        /* bootstrap and kick off the async RPC call */
+        status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, callback, req);
+        if (status < 0)
+                nlm_release_host(host);
+        return status;
+}
+
+/*
+ * 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(req, NLMPROC_TEST);
+        nlmclnt_release_lockargs(req);
+        if (status < 0)
+                return status;
+
+        status = req->a_res.status;
+        if (status == NLM_LCK_GRANTED) {
+                fl->fl_type = F_UNLCK;
+        } if (status == NLM_LCK_DENIED) {
+                /*
+                 * Report the conflicting lock back to the application.
+                 */
+                locks_copy_lock(fl, &req->a_res.lock.fl);
+                fl->fl_pid = 0;
+        } else {
+                return nlm_stat_to_errno(req->a_res.status);
+        }
+
+        return 0;
+}
+
+static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
+{
+        memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
+        nlm_get_lockowner(new->fl_u.nfs_fl.owner);
+}
+
+static void nlmclnt_locks_release_private(struct file_lock *fl)
+{
+        nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
+        fl->fl_ops = NULL;
+}
+
+static 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)
+{
+        BUG_ON(fl->fl_ops != NULL);
+        fl->fl_u.nfs_fl.state = 0;
+        fl->fl_u.nfs_fl.flags = 0;
+        fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
+        fl->fl_ops = &nlmclnt_lock_ops;
+}
+
+static void do_vfs_lock(struct file_lock *fl)
+{
+        int res = 0;
+        switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
+                case FL_POSIX:
+                        res = posix_lock_file_wait(fl->fl_file, fl);
+                        break;
+                case FL_FLOCK:
+                        res = flock_lock_file_wait(fl->fl_file, fl);
+                        break;
+                default:
+                        BUG();
+        }
+        if (res < 0)
+                printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
+                                __FUNCTION__);
+}
+
+/*
+ * 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 nlm_host *host = req->a_host;
+        struct nlm_res  *resp = &req->a_res;
+        int             status;
+
+        if (!host->h_monitored && nsm_monitor(host) < 0) {
+                printk(KERN_NOTICE "lockd: failed to monitor %s\n",
+                                        host->h_name);
+                status = -ENOLCK;
+                goto out;
+        }
+
+        do {
+                if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0) {
+                        if (resp->status != NLM_LCK_BLOCKED)
+                                break;
+                        status = nlmclnt_block(host, fl, &resp->status);
+                }
+                if (status < 0)
+                        goto out;
+        } while (resp->status == NLM_LCK_BLOCKED && req->a_args.block);
+
+        if (resp->status == NLM_LCK_GRANTED) {
+                fl->fl_u.nfs_fl.state = host->h_state;
+                fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
+                fl->fl_flags |= FL_SLEEP;
+                do_vfs_lock(fl);
+        }
+        status = nlm_stat_to_errno(resp->status);
+out:
+        nlmclnt_release_lockargs(req);
+        return status;
+}
+
+/*
+ * RECLAIM: Try to reclaim a lock
+ */
+int
+nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
+{
+        struct nlm_rqst reqst, *req;
+        int             status;
+
+        req = &reqst;
+        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;
+        req->a_flags = 0;
+
+        /* Set up the argument struct */
+        nlmclnt_setlockargs(req, fl);
+        req->a_args.reclaim = 1;
+
+        if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
+         && req->a_res.status == NLM_LCK_GRANTED)
+                return 0;
+
+        printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
+                                "(errno %d, status %d)\n", fl->fl_pid,
+                                status, 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_res  *resp = &req->a_res;
+        int             status;
+
+        /* Clean the GRANTED flag now so the lock doesn't get
+         * reclaimed while we're stuck in the unlock call. */
+        fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
+
+        if (req->a_flags & RPC_TASK_ASYNC) {
+                status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
+                                        nlmclnt_unlock_callback);
+                /* Hrmf... Do the unlock early since locks_remove_posix()
+                 * really expects us to free the lock synchronously */
+                do_vfs_lock(fl);
+                if (status < 0) {
+                        nlmclnt_release_lockargs(req);
+                        kfree(req);
+                }
+                return status;
+        }
+
+        status = nlmclnt_call(req, NLMPROC_UNLOCK);
+        nlmclnt_release_lockargs(req);
+        if (status < 0)
+                return status;
+
+        do_vfs_lock(fl);
+        if (resp->status == NLM_LCK_GRANTED)
+                return 0;
+
+        if (resp->status != NLM_LCK_DENIED_NOLOCKS)
+                printk("lockd: unexpected unlock status: %d\n", resp->status);
+
+        /* What to do now? I'm out of my depth... */
+
+        return -ENOLCK;
+}
+
+static void
+nlmclnt_unlock_callback(struct rpc_task *task)
+{
+        struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
+        int             status = 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);
+                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:
+        nlm_release_host(req->a_host);
+        nlmclnt_release_lockargs(req);
+        kfree(req);
+        return;
+ retry_rebind:
+        nlm_rebind_host(req->a_host);
+ retry_unlock:
+        rpc_restart_call(task);
+}
+
+/*
+ * 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.
+ */
+int
+nlmclnt_cancel(struct nlm_host *host, struct file_lock *fl)
+{
+        struct nlm_rqst *req;
+        unsigned long   flags;
+        sigset_t        oldset;
+        int             status;
+
+        /* Block all signals while setting up call */
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        oldset = current->blocked;
+        sigfillset(&current->blocked);
+        recalc_sigpending();
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
+
+        req = nlmclnt_alloc_call();
+        if (!req)
+                return -ENOMEM;
+        req->a_host  = host;
+        req->a_flags = RPC_TASK_ASYNC;
+
+        nlmclnt_setlockargs(req, fl);
+
+        status = nlmclnt_async_call(req, NLMPROC_CANCEL,
+                                        nlmclnt_cancel_callback);
+        if (status < 0) {
+                nlmclnt_release_lockargs(req);
+                kfree(req);
+        }
+
+        spin_lock_irqsave(&current->sighand->siglock, flags);
+        current->blocked = oldset;
+        recalc_sigpending();
+        spin_unlock_irqrestore(&current->sighand->siglock, flags);
+
+        return status;
+}
+
+static void
+nlmclnt_cancel_callback(struct rpc_task *task)
+{
+        struct nlm_rqst *req = (struct nlm_rqst *) task->tk_calldata;
+
+        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 %d (task %d)\n",
+                        req->a_res.status, task->tk_pid);
+
+        switch (req->a_res.status) {
+        case NLM_LCK_GRANTED:
+        case NLM_LCK_DENIED_GRACE_PERIOD:
+                /* 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",
+                        req->a_res.status);
+        }
+
+die:
+        nlm_release_host(req->a_host);
+        nlmclnt_release_lockargs(req);
+        kfree(req);
+        return;
+
+retry_cancel:
+        nlm_rebind_host(req->a_host);
+        rpc_restart_call(task);
+        rpc_delay(task, 30 * HZ);
+}
+
+/*
+ * Convert an NLM status code to a generic kernel errno
+ */
+static int
+nlm_stat_to_errno(u32 status)
+{
+        switch(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", status);
+        return -ENOLCK;
+}