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fs/lockd/clntproc.c
20.8 KB
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/* * linux/fs/lockd/clntproc.c * * RPC procedures for the client side NLM implementation * * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ |
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#include <linux/module.h> |
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#include <linux/smp_lock.h> |
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#include <linux/slab.h> |
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#include <linux/types.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/nfs_fs.h> #include <linux/utsname.h> |
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#include <linux/freezer.h> |
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#include <linux/sunrpc/clnt.h> #include <linux/sunrpc/svc.h> #include <linux/lockd/lockd.h> |
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#define NLMDBG_FACILITY NLMDBG_CLIENT #define NLMCLNT_GRACE_WAIT (5*HZ) |
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#define NLMCLNT_POLL_TIMEOUT (30*HZ) |
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#define NLMCLNT_MAX_RETRIES 3 |
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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 *); |
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static int nlm_stat_to_errno(__be32 stat); |
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static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); |
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static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
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static const struct rpc_call_ops nlmclnt_unlock_ops; static const struct rpc_call_ops nlmclnt_cancel_ops; |
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/* * Cookie counter for NLM requests */ |
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static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
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void nlmclnt_next_cookie(struct nlm_cookie *c) |
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{ |
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u32 cookie = atomic_inc_return(&nlm_cookie); memcpy(c->data, &cookie, 4); |
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c->len=4; |
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} 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); |
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new = kmalloc(sizeof(*new), GFP_KERNEL); |
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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); |
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kfree(new); |
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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); |
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memcpy(&lock->fh, NFS_FH(fl->fl_file->f_path.dentry->d_inode), sizeof(struct nfs_fh)); |
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lock->caller = utsname()->nodename; |
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lock->oh.data = req->a_owner; |
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lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", (unsigned int)fl->fl_u.nfs_fl.owner->pid, |
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utsname()->nodename); |
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lock->svid = fl->fl_u.nfs_fl.owner->pid; |
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lock->fl.fl_start = fl->fl_start; lock->fl.fl_end = fl->fl_end; lock->fl.fl_type = fl->fl_type; |
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} static void nlmclnt_release_lockargs(struct nlm_rqst *req) { |
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BUG_ON(req->a_args.lock.fl.fl_ops != NULL); |
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} |
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/** * 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 * |
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*/ |
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int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl) |
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{ |
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struct nlm_rqst *call; |
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int status; |
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nlm_get_host(host); |
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call = nlm_alloc_call(host); if (call == NULL) return -ENOMEM; |
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nlmclnt_locks_init_private(fl, host); /* Set up the argument struct */ nlmclnt_setlockargs(call, fl); |
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lock_kernel(); |
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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; |
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fl->fl_ops->fl_release_private(fl); fl->fl_ops = NULL; |
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unlock_kernel(); |
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dprintk("lockd: clnt proc returns %d ", status); |
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return status; } |
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EXPORT_SYMBOL_GPL(nlmclnt_proc); |
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/* * Allocate an NLM RPC call struct |
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* * Note: the caller must hold a reference to host. In case of failure, * this reference will be released. |
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*/ |
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struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
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{ struct nlm_rqst *call; |
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for(;;) { call = kzalloc(sizeof(*call), GFP_KERNEL); if (call != NULL) { |
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atomic_set(&call->a_count, 1); |
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locks_init_lock(&call->a_args.lock.fl); locks_init_lock(&call->a_res.lock.fl); |
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call->a_host = host; |
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return call; } |
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if (signalled()) break; |
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printk("nlm_alloc_call: failed, waiting for memory "); |
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schedule_timeout_interruptible(5*HZ); |
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} |
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nlm_release_host(host); |
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return NULL; } |
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void nlm_release_call(struct nlm_rqst *call) { |
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if (!atomic_dec_and_test(&call->a_count)) return; |
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nlm_release_host(call->a_host); nlmclnt_release_lockargs(call); kfree(call); } static void nlmclnt_rpc_release(void *data) { |
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lock_kernel(); |
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nlm_release_call(data); |
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unlock_kernel(); |
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} |
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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); |
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try_to_freeze(); |
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if (!signalled ()) status = 0; } finish_wait(queue, &wait); return status; } /* * Generic NLM call */ static int |
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nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc) |
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{ 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, |
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.rpc_cred = cred, |
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}; int status; dprintk("lockd: call procedure %d on %s ", (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 ", -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 |
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if (resp->status == nlm_lck_denied_grace_period) { |
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dprintk("lockd: server in grace period "); if (argp->reclaim) { printk(KERN_WARNING "lockd: spurious grace period reject?! "); 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 ", 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. */ |
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static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
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{ struct nlm_host *host = req->a_host; struct rpc_clnt *clnt; |
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struct rpc_task_setup task_setup_data = { .rpc_message = msg, .callback_ops = tk_ops, .callback_data = req, .flags = RPC_TASK_ASYNC, }; |
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dprintk("lockd: call procedure %d on %s (async) ", (int)proc, host->h_name); /* If we have no RPC client yet, create one. */ |
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clnt = nlm_bind_host(host); if (clnt == NULL) goto out_err; |
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msg->rpc_proc = &clnt->cl_procinfo[proc]; |
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task_setup_data.rpc_client = clnt; |
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/* bootstrap and kick off the async RPC call */ |
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return rpc_run_task(&task_setup_data); |
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out_err: |
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tk_ops->rpc_release(req); |
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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; |
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} |
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/* * NLM asynchronous call. */ |
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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, }; |
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return nlm_do_async_call(req, proc, &msg, tk_ops); |
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} 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, }; |
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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. */ |
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static int nlmclnt_async_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops) |
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{ struct rpc_message msg = { .rpc_argp = &req->a_args, .rpc_resp = &req->a_res, |
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.rpc_cred = cred, |
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}; 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; |
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} |
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/* * TEST for the presence of a conflicting lock */ static int nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) { int status; |
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status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST); |
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if (status < 0) |
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goto out; |
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switch (req->a_res.status) { |
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case nlm_granted: |
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fl->fl_type = F_UNLCK; break; |
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case nlm_lck_denied: |
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/* * Report the conflicting lock back to the application. */ fl->fl_start = req->a_res.lock.fl.fl_start; |
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fl->fl_end = req->a_res.lock.fl.fl_end; |
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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); |
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} |
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out: nlm_release_call(req); return status; |
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} static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) { |
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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); |
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} static void nlmclnt_locks_release_private(struct file_lock *fl) { |
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list_del(&fl->fl_u.nfs_fl.list); |
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nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
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} |
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static const struct file_lock_operations nlmclnt_lock_ops = { |
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.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; |
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fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
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INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
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fl->fl_ops = &nlmclnt_lock_ops; } |
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static int do_vfs_lock(struct file_lock *fl) |
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{ 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(); } |
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return res; |
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} /* * 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) { |
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struct rpc_cred *cred = nfs_file_cred(fl->fl_file); |
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struct nlm_host *host = req->a_host; struct nlm_res *resp = &req->a_res; |
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struct nlm_wait *block = NULL; |
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unsigned char fl_flags = fl->fl_flags; |
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unsigned char fl_type; |
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int status = -ENOLCK; |
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|
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if (nsm_monitor(host) < 0) |
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goto out; |
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req->a_args.state = nsm_local_state; |
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|
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fl->fl_flags |= FL_ACCESS; status = do_vfs_lock(fl); |
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fl->fl_flags = fl_flags; |
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if (status < 0) goto out; |
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block = nlmclnt_prepare_block(host, fl); |
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again: |
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/* * Initialise resp->status to a valid non-zero value, * since 0 == nlm_lck_granted */ resp->status = nlm_lck_blocked; |
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for(;;) { |
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/* Reboot protection */ fl->fl_u.nfs_fl.state = host->h_state; |
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status = nlmclnt_call(cred, req, NLMPROC_LOCK); |
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if (status < 0) |
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break; |
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/* Did a reclaimer thread notify us of a server reboot? */ |
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if (resp->status == nlm_lck_denied_grace_period) |
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continue; |
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if (resp->status != nlm_lck_blocked) |
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break; |
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|
547 548 |
/* Wait on an NLM blocking lock */ status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT); |
3a649b884
|
549 |
if (status < 0) |
5f50c0c6d
|
550 |
break; |
e8c5c045d
|
551 |
if (resp->status != nlm_lck_blocked) |
3a649b884
|
552 |
break; |
ecdbf769b
|
553 |
} |
1da177e4c
|
554 |
|
5f50c0c6d
|
555 556 557 558 559 560 561 562 563 |
/* 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; } |
e8c5c045d
|
564 |
if (resp->status == nlm_granted) { |
28df955a2
|
565 566 567 568 569 570 |
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; } |
4c060b531
|
571 |
/* Ensure the resulting lock will get added to granted list */ |
4a9af59fe
|
572 |
fl->fl_flags |= FL_SLEEP; |
9b0735749
|
573 |
if (do_vfs_lock(fl) < 0) |
8e24eea72
|
574 575 |
printk(KERN_WARNING "%s: VFS is out of sync with lock manager! ", __func__); |
28df955a2
|
576 |
up_read(&host->h_rwsem); |
4a9af59fe
|
577 |
fl->fl_flags = fl_flags; |
5f50c0c6d
|
578 |
status = 0; |
1da177e4c
|
579 |
} |
5f50c0c6d
|
580 581 |
if (status < 0) goto out_unlock; |
cc77b1521
|
582 583 584 585 586 587 588 589 590 |
/* * 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); |
ecdbf769b
|
591 |
out_unblock: |
3a649b884
|
592 |
nlmclnt_finish_block(block); |
1da177e4c
|
593 |
out: |
92737230d
|
594 |
nlm_release_call(req); |
1da177e4c
|
595 |
return status; |
5f50c0c6d
|
596 597 598 599 600 601 602 603 604 605 606 607 608 609 |
out_unlock: /* Fatal error: ensure that we remove the lock altogether */ dprintk("lockd: lock attempt ended in fatal error. " " Attempting to unlock. "); 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; |
d11d10cc0
|
610 |
nlmclnt_async_call(cred, req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); |
5f50c0c6d
|
611 |
return status; |
1da177e4c
|
612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 |
} /* * 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; |
d11d10cc0
|
633 634 |
status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_LOCK); if (status >= 0 && req->a_res.status == nlm_granted) |
1da177e4c
|
635 636 637 638 639 |
return 0; printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d " "(errno %d, status %d) ", fl->fl_pid, |
e8c5c045d
|
640 |
status, ntohl(req->a_res.status)); |
1da177e4c
|
641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 |
/* * 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) { |
28df955a2
|
663 |
struct nlm_host *host = req->a_host; |
1da177e4c
|
664 |
struct nlm_res *resp = &req->a_res; |
4a9af59fe
|
665 666 |
int status; unsigned char fl_flags = fl->fl_flags; |
1da177e4c
|
667 |
|
26bcbf965
|
668 |
/* |
30f4e20a0
|
669 670 671 672 |
* 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. */ |
9b0735749
|
673 |
fl->fl_flags |= FL_EXISTS; |
28df955a2
|
674 |
down_read(&host->h_rwsem); |
4a9af59fe
|
675 676 677 678 679 |
status = do_vfs_lock(fl); up_read(&host->h_rwsem); fl->fl_flags = fl_flags; if (status == -ENOENT) { status = 0; |
9b0735749
|
680 681 |
goto out; } |
30f4e20a0
|
682 |
|
dc9d8d048
|
683 |
atomic_inc(&req->a_count); |
d11d10cc0
|
684 685 |
status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, NLMPROC_UNLOCK, &nlmclnt_unlock_ops); |
1da177e4c
|
686 |
if (status < 0) |
92737230d
|
687 |
goto out; |
1da177e4c
|
688 |
|
e8c5c045d
|
689 |
if (resp->status == nlm_granted) |
92737230d
|
690 |
goto out; |
1da177e4c
|
691 |
|
e8c5c045d
|
692 |
if (resp->status != nlm_lck_denied_nolocks) |
1da177e4c
|
693 694 |
printk("lockd: unexpected unlock status: %d ", resp->status); |
1da177e4c
|
695 |
/* What to do now? I'm out of my depth... */ |
92737230d
|
696 697 698 699 |
status = -ENOLCK; out: nlm_release_call(req); return status; |
1da177e4c
|
700 |
} |
963d8fe53
|
701 |
static void nlmclnt_unlock_callback(struct rpc_task *task, void *data) |
1da177e4c
|
702 |
{ |
963d8fe53
|
703 |
struct nlm_rqst *req = data; |
e8c5c045d
|
704 |
u32 status = ntohl(req->a_res.status); |
1da177e4c
|
705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 |
if (RPC_ASSASSINATED(task)) goto die; if (task->tk_status < 0) { dprintk("lockd: unlock failed (err = %d) ", -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 ", status); die: |
1da177e4c
|
722 723 |
return; retry_rebind: |
a86dc496b
|
724 |
lock_kernel(); |
1da177e4c
|
725 |
nlm_rebind_host(req->a_host); |
a86dc496b
|
726 |
unlock_kernel(); |
1da177e4c
|
727 728 729 |
retry_unlock: rpc_restart_call(task); } |
963d8fe53
|
730 731 |
static const struct rpc_call_ops nlmclnt_unlock_ops = { .rpc_call_done = nlmclnt_unlock_callback, |
92737230d
|
732 |
.rpc_release = nlmclnt_rpc_release, |
963d8fe53
|
733 |
}; |
1da177e4c
|
734 735 736 737 738 |
/* * 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. */ |
16fb24252
|
739 |
static int nlmclnt_cancel(struct nlm_host *host, int block, struct file_lock *fl) |
1da177e4c
|
740 741 |
{ struct nlm_rqst *req; |
6b4b3a752
|
742 743 744 745 746 747 |
int status; dprintk("lockd: blocking lock attempt was interrupted by a signal. " " Attempting to cancel lock. "); |
1da177e4c
|
748 |
|
92737230d
|
749 |
req = nlm_alloc_call(nlm_get_host(host)); |
1da177e4c
|
750 751 |
if (!req) return -ENOMEM; |
1da177e4c
|
752 753 754 |
req->a_flags = RPC_TASK_ASYNC; nlmclnt_setlockargs(req, fl); |
16fb24252
|
755 |
req->a_args.block = block; |
1da177e4c
|
756 |
|
6b4b3a752
|
757 |
atomic_inc(&req->a_count); |
d11d10cc0
|
758 759 |
status = nlmclnt_async_call(nfs_file_cred(fl->fl_file), req, NLMPROC_CANCEL, &nlmclnt_cancel_ops); |
6b4b3a752
|
760 761 762 763 |
if (status == 0 && req->a_res.status == nlm_lck_denied) status = -ENOLCK; nlm_release_call(req); return status; |
1da177e4c
|
764 |
} |
963d8fe53
|
765 |
static void nlmclnt_cancel_callback(struct rpc_task *task, void *data) |
1da177e4c
|
766 |
{ |
963d8fe53
|
767 |
struct nlm_rqst *req = data; |
e8c5c045d
|
768 |
u32 status = ntohl(req->a_res.status); |
1da177e4c
|
769 770 771 772 773 774 775 776 777 778 |
if (RPC_ASSASSINATED(task)) goto die; if (task->tk_status < 0) { dprintk("lockd: CANCEL call error %d, retrying. ", task->tk_status); goto retry_cancel; } |
c041b5ff8
|
779 780 |
dprintk("lockd: cancel status %u (task %u) ", |
e8c5c045d
|
781 |
status, task->tk_pid); |
1da177e4c
|
782 |
|
e8c5c045d
|
783 |
switch (status) { |
1da177e4c
|
784 785 |
case NLM_LCK_GRANTED: case NLM_LCK_DENIED_GRACE_PERIOD: |
35576cba5
|
786 |
case NLM_LCK_DENIED: |
1da177e4c
|
787 788 789 790 791 792 793 794 795 |
/* Everything's good */ break; case NLM_LCK_DENIED_NOLOCKS: dprintk("lockd: CANCEL failed (server has no locks) "); goto retry_cancel; default: printk(KERN_NOTICE "lockd: weird return %d for CANCEL call ", |
e8c5c045d
|
796 |
status); |
1da177e4c
|
797 798 799 |
} die: |
1da177e4c
|
800 801 802 |
return; retry_cancel: |
aaaa99423
|
803 804 805 |
/* Don't ever retry more than 3 times */ if (req->a_retries++ >= NLMCLNT_MAX_RETRIES) goto die; |
a86dc496b
|
806 |
lock_kernel(); |
1da177e4c
|
807 |
nlm_rebind_host(req->a_host); |
a86dc496b
|
808 |
unlock_kernel(); |
1da177e4c
|
809 810 811 |
rpc_restart_call(task); rpc_delay(task, 30 * HZ); } |
963d8fe53
|
812 813 |
static const struct rpc_call_ops nlmclnt_cancel_ops = { .rpc_call_done = nlmclnt_cancel_callback, |
92737230d
|
814 |
.rpc_release = nlmclnt_rpc_release, |
963d8fe53
|
815 |
}; |
1da177e4c
|
816 817 818 819 |
/* * Convert an NLM status code to a generic kernel errno */ static int |
e8c5c045d
|
820 |
nlm_stat_to_errno(__be32 status) |
1da177e4c
|
821 |
{ |
e8c5c045d
|
822 |
switch(ntohl(status)) { |
1da177e4c
|
823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 |
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 "); 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 ", status); return -ENOLCK; } |