mirror of https://gitee.com/openkylin/linux.git
840 lines
21 KiB
C
840 lines
21 KiB
C
/*
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* linux/fs/lockd/clntproc.c
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*
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* RPC procedures for the client side NLM implementation
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*
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* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/nfs_fs.h>
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#include <linux/utsname.h>
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#include <linux/freezer.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/lockd/lockd.h>
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#include <linux/lockd/sm_inter.h>
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#define NLMDBG_FACILITY NLMDBG_CLIENT
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#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 *);
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static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *);
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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;
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static const struct rpc_call_ops nlmclnt_cancel_ops;
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/*
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* Cookie counter for NLM requests
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*/
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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);
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memcpy(c->data, &cookie, 4);
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c->len=4;
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}
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static struct nlm_lockowner *nlm_get_lockowner(struct nlm_lockowner *lockowner)
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{
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atomic_inc(&lockowner->count);
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return lockowner;
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}
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static void nlm_put_lockowner(struct nlm_lockowner *lockowner)
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{
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if (!atomic_dec_and_lock(&lockowner->count, &lockowner->host->h_lock))
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return;
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list_del(&lockowner->list);
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spin_unlock(&lockowner->host->h_lock);
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nlm_release_host(lockowner->host);
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kfree(lockowner);
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}
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static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid)
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{
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struct nlm_lockowner *lockowner;
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list_for_each_entry(lockowner, &host->h_lockowners, list) {
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if (lockowner->pid == pid)
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return -EBUSY;
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}
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return 0;
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}
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static inline uint32_t __nlm_alloc_pid(struct nlm_host *host)
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{
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uint32_t res;
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do {
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res = host->h_pidcount++;
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} while (nlm_pidbusy(host, res) < 0);
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return res;
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}
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static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
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{
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struct nlm_lockowner *lockowner;
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list_for_each_entry(lockowner, &host->h_lockowners, list) {
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if (lockowner->owner != owner)
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continue;
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return nlm_get_lockowner(lockowner);
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}
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return NULL;
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}
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static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner)
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{
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struct nlm_lockowner *res, *new = NULL;
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spin_lock(&host->h_lock);
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res = __nlm_find_lockowner(host, owner);
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if (res == NULL) {
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spin_unlock(&host->h_lock);
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new = kmalloc(sizeof(*new), GFP_KERNEL);
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spin_lock(&host->h_lock);
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res = __nlm_find_lockowner(host, owner);
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if (res == NULL && new != NULL) {
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res = new;
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atomic_set(&new->count, 1);
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new->owner = owner;
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new->pid = __nlm_alloc_pid(host);
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new->host = nlm_get_host(host);
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list_add(&new->list, &host->h_lockowners);
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new = NULL;
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}
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}
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spin_unlock(&host->h_lock);
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kfree(new);
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return res;
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}
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/*
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* Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls
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*/
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static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl)
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{
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struct nlm_args *argp = &req->a_args;
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struct nlm_lock *lock = &argp->lock;
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nlmclnt_next_cookie(&argp->cookie);
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argp->state = nsm_local_state;
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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",
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(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;
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lock->fl.fl_end = fl->fl_end;
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lock->fl.fl_type = fl->fl_type;
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}
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static void nlmclnt_release_lockargs(struct nlm_rqst *req)
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{
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BUG_ON(req->a_args.lock.fl.fl_ops != NULL);
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}
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/**
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* nlmclnt_proc - Perform a single client-side lock request
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* @host: address of a valid nlm_host context representing the NLM server
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* @cmd: fcntl-style file lock operation to perform
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* @fl: address of arguments for the lock operation
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*
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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);
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if (call == NULL)
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return -ENOMEM;
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nlmclnt_locks_init_private(fl, host);
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/* Set up the argument struct */
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nlmclnt_setlockargs(call, fl);
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if (IS_SETLK(cmd) || IS_SETLKW(cmd)) {
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if (fl->fl_type != F_UNLCK) {
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call->a_args.block = IS_SETLKW(cmd) ? 1 : 0;
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status = nlmclnt_lock(call, fl);
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} else
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status = nlmclnt_unlock(call, fl);
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} else if (IS_GETLK(cmd))
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status = nlmclnt_test(call, fl);
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else
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status = -EINVAL;
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fl->fl_ops->fl_release_private(fl);
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fl->fl_ops = NULL;
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dprintk("lockd: clnt proc returns %d\n", status);
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return status;
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}
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EXPORT_SYMBOL_GPL(nlmclnt_proc);
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/*
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* Allocate an NLM RPC call struct
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*
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* Note: the caller must hold a reference to host. In case of failure,
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* 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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{
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struct nlm_rqst *call;
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for(;;) {
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call = kzalloc(sizeof(*call), GFP_KERNEL);
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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);
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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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}
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if (signalled())
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break;
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printk("nlm_alloc_call: failed, waiting for memory\n");
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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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}
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void nlm_release_call(struct nlm_rqst *call)
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{
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if (!atomic_dec_and_test(&call->a_count))
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return;
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nlm_release_host(call->a_host);
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nlmclnt_release_lockargs(call);
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kfree(call);
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}
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static void nlmclnt_rpc_release(void *data)
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{
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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)
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{
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DEFINE_WAIT(wait);
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int status = -EINTR;
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prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE);
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if (!signalled ()) {
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schedule_timeout(NLMCLNT_GRACE_WAIT);
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try_to_freeze();
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if (!signalled ())
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status = 0;
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}
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finish_wait(queue, &wait);
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return status;
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}
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/*
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* Generic NLM call
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*/
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static int
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nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc)
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{
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struct nlm_host *host = req->a_host;
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struct rpc_clnt *clnt;
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struct nlm_args *argp = &req->a_args;
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struct nlm_res *resp = &req->a_res;
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struct rpc_message msg = {
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.rpc_argp = argp,
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.rpc_resp = resp,
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.rpc_cred = cred,
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};
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int status;
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dprintk("lockd: call procedure %d on %s\n",
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(int)proc, host->h_name);
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do {
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if (host->h_reclaiming && !argp->reclaim)
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goto in_grace_period;
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/* If we have no RPC client yet, create one. */
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if ((clnt = nlm_bind_host(host)) == NULL)
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return -ENOLCK;
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msg.rpc_proc = &clnt->cl_procinfo[proc];
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/* Perform the RPC call. If an error occurs, try again */
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if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) {
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dprintk("lockd: rpc_call returned error %d\n", -status);
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switch (status) {
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case -EPROTONOSUPPORT:
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status = -EINVAL;
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break;
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case -ECONNREFUSED:
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case -ETIMEDOUT:
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case -ENOTCONN:
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nlm_rebind_host(host);
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status = -EAGAIN;
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break;
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case -ERESTARTSYS:
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return signalled () ? -EINTR : status;
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default:
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break;
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}
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break;
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} else
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if (resp->status == nlm_lck_denied_grace_period) {
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dprintk("lockd: server in grace period\n");
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if (argp->reclaim) {
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printk(KERN_WARNING
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"lockd: spurious grace period reject?!\n");
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return -ENOLCK;
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}
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} else {
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if (!argp->reclaim) {
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/* We appear to be out of the grace period */
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wake_up_all(&host->h_gracewait);
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}
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dprintk("lockd: server returns status %d\n", resp->status);
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return 0; /* Okay, call complete */
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}
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in_grace_period:
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/*
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* The server has rebooted and appears to be in the grace
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* period during which locks are only allowed to be
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* reclaimed.
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* We can only back off and try again later.
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*/
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status = nlm_wait_on_grace(&host->h_gracewait);
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} while (status == 0);
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return status;
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}
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/*
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* Generic NLM call, async version.
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*/
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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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{
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struct nlm_host *host = req->a_host;
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struct rpc_clnt *clnt;
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struct rpc_task_setup task_setup_data = {
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.rpc_message = msg,
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.callback_ops = tk_ops,
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.callback_data = req,
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.flags = RPC_TASK_ASYNC,
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};
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dprintk("lockd: call procedure %d on %s (async)\n",
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(int)proc, host->h_name);
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/* If we have no RPC client yet, create one. */
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clnt = nlm_bind_host(host);
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if (clnt == NULL)
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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);
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}
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static int nlm_do_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops)
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{
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struct rpc_task *task;
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task = __nlm_async_call(req, proc, msg, tk_ops);
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if (IS_ERR(task))
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return PTR_ERR(task);
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rpc_put_task(task);
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return 0;
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}
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/*
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* NLM asynchronous call.
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*/
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int nlm_async_call(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
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{
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struct rpc_message msg = {
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.rpc_argp = &req->a_args,
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.rpc_resp = &req->a_res,
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};
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return nlm_do_async_call(req, proc, &msg, tk_ops);
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}
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int nlm_async_reply(struct nlm_rqst *req, u32 proc, const struct rpc_call_ops *tk_ops)
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{
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struct rpc_message msg = {
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.rpc_argp = &req->a_res,
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};
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return nlm_do_async_call(req, proc, &msg, tk_ops);
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}
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/*
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* NLM client asynchronous call.
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*
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* Note that although the calls are asynchronous, and are therefore
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* guaranteed to complete, we still always attempt to wait for
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* completion in order to be able to correctly track the lock
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* state.
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*/
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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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{
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struct rpc_message msg = {
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.rpc_argp = &req->a_args,
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.rpc_resp = &req->a_res,
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.rpc_cred = cred,
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};
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struct rpc_task *task;
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int err;
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task = __nlm_async_call(req, proc, &msg, tk_ops);
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if (IS_ERR(task))
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return PTR_ERR(task);
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err = rpc_wait_for_completion_task(task);
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rpc_put_task(task);
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return err;
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}
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/*
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* TEST for the presence of a conflicting lock
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*/
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static int
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nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
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{
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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;
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break;
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case nlm_lck_denied:
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/*
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* Report the conflicting lock back to the application.
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*/
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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;
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fl->fl_pid = 0;
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break;
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default:
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status = nlm_stat_to_errno(req->a_res.status);
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}
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out:
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nlm_release_call(req);
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return status;
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}
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static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
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{
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new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
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new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
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list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
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}
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static void nlmclnt_locks_release_private(struct file_lock *fl)
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{
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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 struct file_lock_operations nlmclnt_lock_ops = {
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.fl_copy_lock = nlmclnt_locks_copy_lock,
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.fl_release_private = nlmclnt_locks_release_private,
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};
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static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
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{
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BUG_ON(fl->fl_ops != NULL);
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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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}
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static int do_vfs_lock(struct file_lock *fl)
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{
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int res = 0;
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switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
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case FL_POSIX:
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res = posix_lock_file_wait(fl->fl_file, fl);
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break;
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case FL_FLOCK:
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res = flock_lock_file_wait(fl->fl_file, fl);
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break;
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default:
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BUG();
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}
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return res;
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}
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/*
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* LOCK: Try to create a lock
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*
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* Programmer Harassment Alert
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*
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* When given a blocking lock request in a sync RPC call, the HPUX lockd
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* will faithfully return LCK_BLOCKED but never cares to notify us when
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* the lock could be granted. This way, our local process could hang
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* around forever waiting for the callback.
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*
|
|
* 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) {
|
|
printk(KERN_NOTICE "lockd: failed to monitor %s\n",
|
|
host->h_name);
|
|
goto out;
|
|
}
|
|
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;
|
|
status = nlm_stat_to_errno(resp->status);
|
|
out_unblock:
|
|
nlmclnt_finish_block(block);
|
|
out:
|
|
nlm_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 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;
|
|
|
|
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;
|
|
}
|
|
|
|
atomic_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", resp->status);
|
|
/* What to do now? I'm out of my depth... */
|
|
status = -ENOLCK;
|
|
out:
|
|
nlm_release_call(req);
|
|
return status;
|
|
}
|
|
|
|
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);
|
|
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:
|
|
lock_kernel();
|
|
nlm_rebind_host(req->a_host);
|
|
unlock_kernel();
|
|
retry_unlock:
|
|
rpc_restart_call(task);
|
|
}
|
|
|
|
static const struct rpc_call_ops nlmclnt_unlock_ops = {
|
|
.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(nlm_get_host(host));
|
|
if (!req)
|
|
return -ENOMEM;
|
|
req->a_flags = RPC_TASK_ASYNC;
|
|
|
|
nlmclnt_setlockargs(req, fl);
|
|
req->a_args.block = block;
|
|
|
|
atomic_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;
|
|
nlm_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;
|
|
lock_kernel();
|
|
nlm_rebind_host(req->a_host);
|
|
unlock_kernel();
|
|
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", status);
|
|
return -ENOLCK;
|
|
}
|