| /* |
| * 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/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); |
| |
| /* |
| * 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++; |
| } |
| |
| /* |
| * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls |
| */ |
| static inline 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); |
| } |
| |
| /* |
| * 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) |
| 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) |
| { |
| /* |
| * 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); |
| } |
| } |
| |
| /* |
| * 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(¤t->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(¤t->blocked); /* Mask all signals */ |
| recalc_sigpending(); |
| spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| |
| call = nlmclnt_alloc_call(); |
| if (!call) { |
| status = -ENOMEM; |
| goto out_restore; |
| } |
| call->a_flags = RPC_TASK_ASYNC; |
| } else { |
| spin_unlock_irqrestore(¤t->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; |
| |
| /* 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; |
| |
| if (status < 0 && (call->a_flags & RPC_TASK_ASYNC)) |
| kfree(call); |
| |
| out_restore: |
| spin_lock_irqsave(¤t->sighand->siglock, flags); |
| current->blocked = oldset; |
| recalc_sigpending(); |
| spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
| |
| done: |
| dprintk("lockd: clnt proc returns %d\n", status); |
| nlm_release_host(host); |
| return status; |
| } |
| |
| /* |
| * Wait while server is in grace period |
| */ |
| static inline int |
| nlmclnt_grace_wait(struct nlm_host *host) |
| { |
| if (!host->h_reclaiming) |
| interruptible_sleep_on_timeout(&host->h_gracewait, 10*HZ); |
| else |
| interruptible_sleep_on(&host->h_gracewait); |
| return signalled()? -ERESTARTSYS : 0; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * Generic NLM call |
| */ |
| 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 file *filp = argp->lock.fl.fl_file; |
| 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); |
| |
| if (filp) |
| msg.rpc_cred = nfs_file_cred(filp); |
| |
| do { |
| if (host->h_reclaiming && !argp->reclaim) { |
| interruptible_sleep_on(&host->h_gracewait); |
| continue; |
| } |
| |
| /* 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 { |
| dprintk("lockd: server returns status %d\n", resp->status); |
| return 0; /* Okay, call complete */ |
| } |
| |
| /* Back off a little and try again */ |
| interruptible_sleep_on_timeout(&host->h_gracewait, 15*HZ); |
| |
| /* When the lock requested by F_SETLKW isn't available, |
| we will wait until the request can be satisfied. If |
| a signal is received during wait, we should return |
| -EINTR. */ |
| if (signalled ()) { |
| status = -EINTR; |
| break; |
| } |
| } while (1); |
| |
| 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; |
| } |
| |
| 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 file *file = argp->lock.fl.fl_file; |
| 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]; |
| |
| /* bootstrap and kick off the async RPC call */ |
| if (file) |
| msg.rpc_cred = nfs_file_cred(file); |
| /* Increment host refcount */ |
| nlm_get_host(host); |
| 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; |
| |
| if ((status = nlmclnt_call(req, NLMPROC_TEST)) < 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. |
| * FIXME: Is it OK to report the pid back as well? |
| */ |
| 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_insert_lock_callback(struct file_lock *fl) |
| { |
| nlm_get_host(fl->fl_u.nfs_fl.host); |
| } |
| static |
| void nlmclnt_remove_lock_callback(struct file_lock *fl) |
| { |
| if (fl->fl_u.nfs_fl.host) { |
| nlm_release_host(fl->fl_u.nfs_fl.host); |
| fl->fl_u.nfs_fl.host = NULL; |
| } |
| } |
| |
| /* |
| * 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); |
| return -ENOLCK; |
| } |
| |
| 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) |
| return status; |
| } while (resp->status == NLM_LCK_BLOCKED); |
| |
| 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_u.nfs_fl.host = host; |
| fl->fl_insert = nlmclnt_insert_lock_callback; |
| fl->fl_remove = nlmclnt_remove_lock_callback; |
| } |
| |
| return nlm_stat_to_errno(resp->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) { |
| return nlmclnt_async_call(req, NLMPROC_UNLOCK, |
| nlmclnt_unlock_callback); |
| } |
| |
| if ((status = nlmclnt_call(req, NLMPROC_UNLOCK)) < 0) |
| return status; |
| |
| 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); |
| 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(¤t->sighand->siglock, flags); |
| oldset = current->blocked; |
| sigfillset(¤t->blocked); |
| recalc_sigpending(); |
| spin_unlock_irqrestore(¤t->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) |
| kfree(req); |
| |
| spin_lock_irqsave(¤t->sighand->siglock, flags); |
| current->blocked = oldset; |
| recalc_sigpending(); |
| spin_unlock_irqrestore(¤t->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); |
| 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; |
| } |