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If the server returns NLM_LCK_DENIED_NOLOCKS, we currently retry the entire NLM_CANCEL request. This may end up looping forever unless the server changes its mind (why would it do that, though?). Ensure that we limit the number of retries (to 3). See bug# 5957 in bugzilla.kernel.org. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
851 lines
21 KiB
C
851 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/config.h>
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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/smp_lock.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(u32 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 u32 nlm_cookie = 0x1234;
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static inline void nlmclnt_next_cookie(struct nlm_cookie *c)
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{
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memcpy(c->data, &nlm_cookie, 4);
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memset(c->data+4, 0, 4);
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c->len=4;
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nlm_cookie++;
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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 = (struct nlm_lockowner *)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_dentry->d_inode), sizeof(struct nfs_fh));
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lock->caller = system_utsname.nodename;
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lock->oh.data = req->a_owner;
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lock->oh.len = sprintf(req->a_owner, "%d@%s",
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current->pid, system_utsname.nodename);
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locks_copy_lock(&lock->fl, fl);
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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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struct file_lock *fl = &req->a_args.lock.fl;
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if (fl->fl_ops && fl->fl_ops->fl_release_private)
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fl->fl_ops->fl_release_private(fl);
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}
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/*
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* Initialize arguments for GRANTED call. The nlm_rqst structure
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* has been cleared already.
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*/
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int
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nlmclnt_setgrantargs(struct nlm_rqst *call, struct nlm_lock *lock)
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{
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locks_copy_lock(&call->a_args.lock.fl, &lock->fl);
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memcpy(&call->a_args.lock.fh, &lock->fh, sizeof(call->a_args.lock.fh));
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call->a_args.lock.caller = system_utsname.nodename;
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call->a_args.lock.oh.len = lock->oh.len;
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/* set default data area */
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call->a_args.lock.oh.data = call->a_owner;
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if (lock->oh.len > NLMCLNT_OHSIZE) {
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void *data = kmalloc(lock->oh.len, GFP_KERNEL);
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if (!data) {
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nlmclnt_freegrantargs(call);
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return 0;
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}
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call->a_args.lock.oh.data = (u8 *) data;
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}
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memcpy(call->a_args.lock.oh.data, lock->oh.data, lock->oh.len);
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return 1;
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}
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void
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nlmclnt_freegrantargs(struct nlm_rqst *call)
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{
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struct file_lock *fl = &call->a_args.lock.fl;
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/*
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* Check whether we allocated memory for the owner.
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*/
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if (call->a_args.lock.oh.data != (u8 *) call->a_owner) {
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kfree(call->a_args.lock.oh.data);
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}
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if (fl->fl_ops && fl->fl_ops->fl_release_private)
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fl->fl_ops->fl_release_private(fl);
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}
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/*
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* This is the main entry point for the NLM client.
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*/
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int
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nlmclnt_proc(struct inode *inode, int cmd, struct file_lock *fl)
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{
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struct nfs_server *nfssrv = NFS_SERVER(inode);
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struct nlm_host *host;
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struct nlm_rqst reqst, *call = &reqst;
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sigset_t oldset;
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unsigned long flags;
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int status, proto, vers;
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vers = (NFS_PROTO(inode)->version == 3) ? 4 : 1;
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if (NFS_PROTO(inode)->version > 3) {
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printk(KERN_NOTICE "NFSv4 file locking not implemented!\n");
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return -ENOLCK;
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}
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/* Retrieve transport protocol from NFS client */
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proto = NFS_CLIENT(inode)->cl_xprt->prot;
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if (!(host = nlmclnt_lookup_host(NFS_ADDR(inode), proto, vers)))
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return -ENOLCK;
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/* Create RPC client handle if not there, and copy soft
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* and intr flags from NFS client. */
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if (host->h_rpcclnt == NULL) {
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struct rpc_clnt *clnt;
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/* Bind an rpc client to this host handle (does not
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* perform a portmapper lookup) */
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if (!(clnt = nlm_bind_host(host))) {
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status = -ENOLCK;
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goto done;
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}
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clnt->cl_softrtry = nfssrv->client->cl_softrtry;
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clnt->cl_intr = nfssrv->client->cl_intr;
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}
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/* Keep the old signal mask */
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spin_lock_irqsave(¤t->sighand->siglock, flags);
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oldset = current->blocked;
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/* If we're cleaning up locks because the process is exiting,
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* perform the RPC call asynchronously. */
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if ((IS_SETLK(cmd) || IS_SETLKW(cmd))
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&& fl->fl_type == F_UNLCK
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&& (current->flags & PF_EXITING)) {
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sigfillset(¤t->blocked); /* Mask all signals */
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recalc_sigpending();
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spin_unlock_irqrestore(¤t->sighand->siglock, flags);
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call = nlmclnt_alloc_call();
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if (!call) {
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status = -ENOMEM;
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goto out_restore;
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}
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call->a_flags = RPC_TASK_ASYNC;
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} else {
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spin_unlock_irqrestore(¤t->sighand->siglock, flags);
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memset(call, 0, sizeof(*call));
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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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}
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call->a_host = host;
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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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out_restore:
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spin_lock_irqsave(¤t->sighand->siglock, flags);
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current->blocked = oldset;
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recalc_sigpending();
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spin_unlock_irqrestore(¤t->sighand->siglock, flags);
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done:
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dprintk("lockd: clnt proc returns %d\n", status);
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nlm_release_host(host);
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return status;
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}
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EXPORT_SYMBOL(nlmclnt_proc);
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/*
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* Allocate an NLM RPC call struct
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*/
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struct nlm_rqst *
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nlmclnt_alloc_call(void)
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{
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struct nlm_rqst *call;
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while (!signalled()) {
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call = (struct nlm_rqst *) kmalloc(sizeof(struct nlm_rqst), GFP_KERNEL);
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if (call) {
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memset(call, 0, sizeof(*call));
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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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return call;
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}
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printk("nlmclnt_alloc_call: failed, waiting for memory\n");
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schedule_timeout_interruptible(5*HZ);
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}
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return NULL;
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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 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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};
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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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int nlmsvc_async_call(struct nlm_rqst *req, u32 proc, 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_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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int status;
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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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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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/* bootstrap and kick off the async RPC call */
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status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
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return status;
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}
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static int nlmclnt_async_call(struct nlm_rqst *req, u32 proc, 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 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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};
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int status;
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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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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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/* Increment host refcount */
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nlm_get_host(host);
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/* bootstrap and kick off the async RPC call */
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status = rpc_call_async(clnt, &msg, RPC_TASK_ASYNC, tk_ops, req);
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if (status < 0)
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nlm_release_host(host);
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return status;
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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(req, NLMPROC_TEST);
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nlmclnt_release_lockargs(req);
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if (status < 0)
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return status;
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status = req->a_res.status;
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if (status == NLM_LCK_GRANTED) {
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fl->fl_type = F_UNLCK;
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} if (status == 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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locks_copy_lock(fl, &req->a_res.lock.fl);
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fl->fl_pid = 0;
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} else {
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return nlm_stat_to_errno(req->a_res.status);
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}
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return 0;
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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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memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl));
|
|
nlm_get_lockowner(new->fl_u.nfs_fl.owner);
|
|
}
|
|
|
|
static void nlmclnt_locks_release_private(struct file_lock *fl)
|
|
{
|
|
nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
|
|
fl->fl_ops = NULL;
|
|
}
|
|
|
|
static struct file_lock_operations nlmclnt_lock_ops = {
|
|
.fl_copy_lock = nlmclnt_locks_copy_lock,
|
|
.fl_release_private = nlmclnt_locks_release_private,
|
|
};
|
|
|
|
static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host)
|
|
{
|
|
BUG_ON(fl->fl_ops != NULL);
|
|
fl->fl_u.nfs_fl.state = 0;
|
|
fl->fl_u.nfs_fl.flags = 0;
|
|
fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
|
|
fl->fl_ops = &nlmclnt_lock_ops;
|
|
}
|
|
|
|
static void do_vfs_lock(struct file_lock *fl)
|
|
{
|
|
int res = 0;
|
|
switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
|
|
case FL_POSIX:
|
|
res = posix_lock_file_wait(fl->fl_file, fl);
|
|
break;
|
|
case FL_FLOCK:
|
|
res = flock_lock_file_wait(fl->fl_file, fl);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
if (res < 0)
|
|
printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n",
|
|
__FUNCTION__);
|
|
}
|
|
|
|
/*
|
|
* LOCK: Try to create a lock
|
|
*
|
|
* Programmer Harassment Alert
|
|
*
|
|
* When given a blocking lock request in a sync RPC call, the HPUX lockd
|
|
* will faithfully return LCK_BLOCKED but never cares to notify us when
|
|
* the lock could be granted. This way, our local process could hang
|
|
* around forever waiting for the callback.
|
|
*
|
|
* Solution A: Implement busy-waiting
|
|
* Solution B: Use the async version of the call (NLM_LOCK_{MSG,RES})
|
|
*
|
|
* For now I am implementing solution A, because I hate the idea of
|
|
* re-implementing lockd for a third time in two months. The async
|
|
* calls shouldn't be too hard to do, however.
|
|
*
|
|
* This is one of the lovely things about standards in the NFS area:
|
|
* they're so soft and squishy you can't really blame HP for doing this.
|
|
*/
|
|
static int
|
|
nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
|
|
{
|
|
struct nlm_host *host = req->a_host;
|
|
struct nlm_res *resp = &req->a_res;
|
|
long timeout;
|
|
int status;
|
|
|
|
if (!host->h_monitored && nsm_monitor(host) < 0) {
|
|
printk(KERN_NOTICE "lockd: failed to monitor %s\n",
|
|
host->h_name);
|
|
status = -ENOLCK;
|
|
goto out;
|
|
}
|
|
|
|
if (req->a_args.block) {
|
|
status = nlmclnt_prepare_block(req, host, fl);
|
|
if (status < 0)
|
|
goto out;
|
|
}
|
|
for(;;) {
|
|
status = nlmclnt_call(req, NLMPROC_LOCK);
|
|
if (status < 0)
|
|
goto out_unblock;
|
|
if (resp->status != NLM_LCK_BLOCKED)
|
|
break;
|
|
/* Wait on an NLM blocking lock */
|
|
timeout = nlmclnt_block(req, NLMCLNT_POLL_TIMEOUT);
|
|
/* 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;
|
|
if (timeout >= 0)
|
|
continue;
|
|
/* We were interrupted. Send a CANCEL request to the server
|
|
* and exit
|
|
*/
|
|
status = (int)timeout;
|
|
goto out_unblock;
|
|
}
|
|
|
|
if (resp->status == NLM_LCK_GRANTED) {
|
|
fl->fl_u.nfs_fl.state = host->h_state;
|
|
fl->fl_u.nfs_fl.flags |= NFS_LCK_GRANTED;
|
|
fl->fl_flags |= FL_SLEEP;
|
|
do_vfs_lock(fl);
|
|
}
|
|
status = nlm_stat_to_errno(resp->status);
|
|
out_unblock:
|
|
nlmclnt_finish_block(req);
|
|
/* Cancel the blocked request if it is still pending */
|
|
if (resp->status == NLM_LCK_BLOCKED)
|
|
nlmclnt_cancel(host, req->a_args.block, fl);
|
|
out:
|
|
nlmclnt_release_lockargs(req);
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* RECLAIM: Try to reclaim a lock
|
|
*/
|
|
int
|
|
nlmclnt_reclaim(struct nlm_host *host, struct file_lock *fl)
|
|
{
|
|
struct nlm_rqst reqst, *req;
|
|
int status;
|
|
|
|
req = &reqst;
|
|
memset(req, 0, sizeof(*req));
|
|
locks_init_lock(&req->a_args.lock.fl);
|
|
locks_init_lock(&req->a_res.lock.fl);
|
|
req->a_host = host;
|
|
req->a_flags = 0;
|
|
|
|
/* Set up the argument struct */
|
|
nlmclnt_setlockargs(req, fl);
|
|
req->a_args.reclaim = 1;
|
|
|
|
if ((status = nlmclnt_call(req, NLMPROC_LOCK)) >= 0
|
|
&& req->a_res.status == NLM_LCK_GRANTED)
|
|
return 0;
|
|
|
|
printk(KERN_WARNING "lockd: failed to reclaim lock for pid %d "
|
|
"(errno %d, status %d)\n", fl->fl_pid,
|
|
status, req->a_res.status);
|
|
|
|
/*
|
|
* FIXME: This is a serious failure. We can
|
|
*
|
|
* a. Ignore the problem
|
|
* b. Send the owning process some signal (Linux doesn't have
|
|
* SIGLOST, though...)
|
|
* c. Retry the operation
|
|
*
|
|
* Until someone comes up with a simple implementation
|
|
* for b or c, I'll choose option a.
|
|
*/
|
|
|
|
return -ENOLCK;
|
|
}
|
|
|
|
/*
|
|
* UNLOCK: remove an existing lock
|
|
*/
|
|
static int
|
|
nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
|
|
{
|
|
struct nlm_res *resp = &req->a_res;
|
|
int status;
|
|
|
|
/* Clean the GRANTED flag now so the lock doesn't get
|
|
* reclaimed while we're stuck in the unlock call. */
|
|
fl->fl_u.nfs_fl.flags &= ~NFS_LCK_GRANTED;
|
|
|
|
if (req->a_flags & RPC_TASK_ASYNC) {
|
|
status = nlmclnt_async_call(req, NLMPROC_UNLOCK,
|
|
&nlmclnt_unlock_ops);
|
|
/* Hrmf... Do the unlock early since locks_remove_posix()
|
|
* really expects us to free the lock synchronously */
|
|
do_vfs_lock(fl);
|
|
if (status < 0) {
|
|
nlmclnt_release_lockargs(req);
|
|
kfree(req);
|
|
}
|
|
return status;
|
|
}
|
|
|
|
status = nlmclnt_call(req, NLMPROC_UNLOCK);
|
|
nlmclnt_release_lockargs(req);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
do_vfs_lock(fl);
|
|
if (resp->status == NLM_LCK_GRANTED)
|
|
return 0;
|
|
|
|
if (resp->status != NLM_LCK_DENIED_NOLOCKS)
|
|
printk("lockd: unexpected unlock status: %d\n", resp->status);
|
|
|
|
/* What to do now? I'm out of my depth... */
|
|
|
|
return -ENOLCK;
|
|
}
|
|
|
|
static void nlmclnt_unlock_callback(struct rpc_task *task, void *data)
|
|
{
|
|
struct nlm_rqst *req = data;
|
|
int status = req->a_res.status;
|
|
|
|
if (RPC_ASSASSINATED(task))
|
|
goto die;
|
|
|
|
if (task->tk_status < 0) {
|
|
dprintk("lockd: unlock failed (err = %d)\n", -task->tk_status);
|
|
goto retry_rebind;
|
|
}
|
|
if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
|
|
rpc_delay(task, NLMCLNT_GRACE_WAIT);
|
|
goto retry_unlock;
|
|
}
|
|
if (status != NLM_LCK_GRANTED)
|
|
printk(KERN_WARNING "lockd: unexpected unlock status: %d\n", status);
|
|
die:
|
|
nlm_release_host(req->a_host);
|
|
nlmclnt_release_lockargs(req);
|
|
kfree(req);
|
|
return;
|
|
retry_rebind:
|
|
nlm_rebind_host(req->a_host);
|
|
retry_unlock:
|
|
rpc_restart_call(task);
|
|
}
|
|
|
|
static const struct rpc_call_ops nlmclnt_unlock_ops = {
|
|
.rpc_call_done = nlmclnt_unlock_callback,
|
|
};
|
|
|
|
/*
|
|
* 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;
|
|
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);
|
|
req->a_args.block = block;
|
|
|
|
status = nlmclnt_async_call(req, NLMPROC_CANCEL, &nlmclnt_cancel_ops);
|
|
if (status < 0) {
|
|
nlmclnt_release_lockargs(req);
|
|
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, void *data)
|
|
{
|
|
struct nlm_rqst *req = data;
|
|
|
|
if (RPC_ASSASSINATED(task))
|
|
goto die;
|
|
|
|
if (task->tk_status < 0) {
|
|
dprintk("lockd: CANCEL call error %d, retrying.\n",
|
|
task->tk_status);
|
|
goto retry_cancel;
|
|
}
|
|
|
|
dprintk("lockd: cancel status %d (task %d)\n",
|
|
req->a_res.status, task->tk_pid);
|
|
|
|
switch (req->a_res.status) {
|
|
case NLM_LCK_GRANTED:
|
|
case NLM_LCK_DENIED_GRACE_PERIOD:
|
|
/* Everything's good */
|
|
break;
|
|
case NLM_LCK_DENIED_NOLOCKS:
|
|
dprintk("lockd: CANCEL failed (server has no locks)\n");
|
|
goto retry_cancel;
|
|
default:
|
|
printk(KERN_NOTICE "lockd: weird return %d for CANCEL call\n",
|
|
req->a_res.status);
|
|
}
|
|
|
|
die:
|
|
nlm_release_host(req->a_host);
|
|
nlmclnt_release_lockargs(req);
|
|
kfree(req);
|
|
return;
|
|
|
|
retry_cancel:
|
|
/* Don't ever retry more than 3 times */
|
|
if (req->a_retries++ >= NLMCLNT_MAX_RETRIES)
|
|
goto die;
|
|
nlm_rebind_host(req->a_host);
|
|
rpc_restart_call(task);
|
|
rpc_delay(task, 30 * HZ);
|
|
}
|
|
|
|
static const struct rpc_call_ops nlmclnt_cancel_ops = {
|
|
.rpc_call_done = nlmclnt_cancel_callback,
|
|
};
|
|
|
|
/*
|
|
* 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;
|
|
}
|