| /* |
| * linux/fs/lockd/clntproc.c |
| * |
| * RPC procedures for the client side NLM implementation |
| * |
| * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/fs.h> |
| #include <linux/nfs_fs.h> |
| #include <linux/utsname.h> |
| #include <linux/freezer.h> |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/sunrpc/svc.h> |
| #include <linux/lockd/lockd.h> |
| |
| #define NLMDBG_FACILITY NLMDBG_CLIENT |
| #define NLMCLNT_GRACE_WAIT (5*HZ) |
| #define NLMCLNT_POLL_TIMEOUT (30*HZ) |
| #define NLMCLNT_MAX_RETRIES 3 |
| |
| static int nlmclnt_test(struct nlm_rqst *, struct file_lock *); |
| static int nlmclnt_lock(struct nlm_rqst *, struct file_lock *); |
| static int nlmclnt_unlock(struct nlm_rqst *, struct file_lock *); |
| static int nlm_stat_to_errno(__be32 stat); |
| static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *host); |
| static int nlmclnt_cancel(struct nlm_host *, int , struct file_lock *); |
| |
| static const struct rpc_call_ops nlmclnt_unlock_ops; |
| static const struct rpc_call_ops nlmclnt_cancel_ops; |
| |
| /* |
| * Cookie counter for NLM requests |
| */ |
| static atomic_t nlm_cookie = ATOMIC_INIT(0x1234); |
| |
| void nlmclnt_next_cookie(struct nlm_cookie *c) |
| { |
| u32 cookie = atomic_inc_return(&nlm_cookie); |
| |
| memcpy(c->data, &cookie, 4); |
| c->len=4; |
| } |
| |
| 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); |
| nlmclnt_release_host(lockowner->host); |
| kfree(lockowner); |
| } |
| |
| static inline int nlm_pidbusy(struct nlm_host *host, uint32_t pid) |
| { |
| struct nlm_lockowner *lockowner; |
| list_for_each_entry(lockowner, &host->h_lockowners, list) { |
| if (lockowner->pid == pid) |
| return -EBUSY; |
| } |
| return 0; |
| } |
| |
| static inline uint32_t __nlm_alloc_pid(struct nlm_host *host) |
| { |
| uint32_t res; |
| do { |
| res = host->h_pidcount++; |
| } while (nlm_pidbusy(host, res) < 0); |
| return res; |
| } |
| |
| static struct nlm_lockowner *__nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) |
| { |
| struct nlm_lockowner *lockowner; |
| list_for_each_entry(lockowner, &host->h_lockowners, list) { |
| if (lockowner->owner != owner) |
| continue; |
| return nlm_get_lockowner(lockowner); |
| } |
| return NULL; |
| } |
| |
| static struct nlm_lockowner *nlm_find_lockowner(struct nlm_host *host, fl_owner_t owner) |
| { |
| struct nlm_lockowner *res, *new = NULL; |
| |
| spin_lock(&host->h_lock); |
| res = __nlm_find_lockowner(host, owner); |
| if (res == NULL) { |
| spin_unlock(&host->h_lock); |
| new = kmalloc(sizeof(*new), GFP_KERNEL); |
| spin_lock(&host->h_lock); |
| res = __nlm_find_lockowner(host, owner); |
| if (res == NULL && new != NULL) { |
| res = new; |
| atomic_set(&new->count, 1); |
| new->owner = owner; |
| new->pid = __nlm_alloc_pid(host); |
| new->host = nlm_get_host(host); |
| list_add(&new->list, &host->h_lockowners); |
| new = NULL; |
| } |
| } |
| spin_unlock(&host->h_lock); |
| kfree(new); |
| return res; |
| } |
| |
| /* |
| * Initialize arguments for TEST/LOCK/UNLOCK/CANCEL calls |
| */ |
| static void nlmclnt_setlockargs(struct nlm_rqst *req, struct file_lock *fl) |
| { |
| struct nlm_args *argp = &req->a_args; |
| struct nlm_lock *lock = &argp->lock; |
| |
| nlmclnt_next_cookie(&argp->cookie); |
| memcpy(&lock->fh, NFS_FH(file_inode(fl->fl_file)), sizeof(struct nfs_fh)); |
| lock->caller = utsname()->nodename; |
| lock->oh.data = req->a_owner; |
| lock->oh.len = snprintf(req->a_owner, sizeof(req->a_owner), "%u@%s", |
| (unsigned int)fl->fl_u.nfs_fl.owner->pid, |
| utsname()->nodename); |
| lock->svid = fl->fl_u.nfs_fl.owner->pid; |
| lock->fl.fl_start = fl->fl_start; |
| lock->fl.fl_end = fl->fl_end; |
| lock->fl.fl_type = fl->fl_type; |
| } |
| |
| static void nlmclnt_release_lockargs(struct nlm_rqst *req) |
| { |
| WARN_ON_ONCE(req->a_args.lock.fl.fl_ops != NULL); |
| } |
| |
| /** |
| * 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 |
| * |
| */ |
| int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl) |
| { |
| struct nlm_rqst *call; |
| int status; |
| |
| call = nlm_alloc_call(host); |
| if (call == NULL) |
| return -ENOMEM; |
| |
| nlmclnt_locks_init_private(fl, host); |
| if (!fl->fl_u.nfs_fl.owner) { |
| /* lockowner allocation has failed */ |
| nlmclnt_release_call(call); |
| return -ENOMEM; |
| } |
| /* Set up the argument struct */ |
| nlmclnt_setlockargs(call, fl); |
| |
| if (IS_SETLK(cmd) || IS_SETLKW(cmd)) { |
| if (fl->fl_type != F_UNLCK) { |
| call->a_args.block = IS_SETLKW(cmd) ? 1 : 0; |
| status = nlmclnt_lock(call, fl); |
| } else |
| status = nlmclnt_unlock(call, fl); |
| } else if (IS_GETLK(cmd)) |
| status = nlmclnt_test(call, fl); |
| else |
| status = -EINVAL; |
| fl->fl_ops->fl_release_private(fl); |
| fl->fl_ops = NULL; |
| |
| dprintk("lockd: clnt proc returns %d\n", status); |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(nlmclnt_proc); |
| |
| /* |
| * Allocate an NLM RPC call struct |
| */ |
| struct nlm_rqst *nlm_alloc_call(struct nlm_host *host) |
| { |
| struct nlm_rqst *call; |
| |
| for(;;) { |
| call = kzalloc(sizeof(*call), GFP_KERNEL); |
| if (call != NULL) { |
| atomic_set(&call->a_count, 1); |
| locks_init_lock(&call->a_args.lock.fl); |
| locks_init_lock(&call->a_res.lock.fl); |
| call->a_host = nlm_get_host(host); |
| return call; |
| } |
| if (signalled()) |
| break; |
| printk("nlm_alloc_call: failed, waiting for memory\n"); |
| schedule_timeout_interruptible(5*HZ); |
| } |
| return NULL; |
| } |
| |
| void nlmclnt_release_call(struct nlm_rqst *call) |
| { |
| if (!atomic_dec_and_test(&call->a_count)) |
| return; |
| nlmclnt_release_host(call->a_host); |
| nlmclnt_release_lockargs(call); |
| kfree(call); |
| } |
| |
| static void nlmclnt_rpc_release(void *data) |
| { |
| nlmclnt_release_call(data); |
| } |
| |
| static int nlm_wait_on_grace(wait_queue_head_t *queue) |
| { |
| DEFINE_WAIT(wait); |
| int status = -EINTR; |
| |
| prepare_to_wait(queue, &wait, TASK_INTERRUPTIBLE); |
| if (!signalled ()) { |
| schedule_timeout(NLMCLNT_GRACE_WAIT); |
| try_to_freeze(); |
| if (!signalled ()) |
| status = 0; |
| } |
| finish_wait(queue, &wait); |
| return status; |
| } |
| |
| /* |
| * Generic NLM call |
| */ |
| static int |
| nlmclnt_call(struct rpc_cred *cred, struct nlm_rqst *req, u32 proc) |
| { |
| struct nlm_host *host = req->a_host; |
| struct rpc_clnt *clnt; |
| struct nlm_args *argp = &req->a_args; |
| struct nlm_res *resp = &req->a_res; |
| struct rpc_message msg = { |
| .rpc_argp = argp, |
| .rpc_resp = resp, |
| .rpc_cred = cred, |
| }; |
| int status; |
| |
| dprintk("lockd: call procedure %d on %s\n", |
| (int)proc, host->h_name); |
| |
| do { |
| if (host->h_reclaiming && !argp->reclaim) |
| goto in_grace_period; |
| |
| /* If we have no RPC client yet, create one. */ |
| if ((clnt = nlm_bind_host(host)) == NULL) |
| return -ENOLCK; |
| msg.rpc_proc = &clnt->cl_procinfo[proc]; |
| |
| /* Perform the RPC call. If an error occurs, try again */ |
| if ((status = rpc_call_sync(clnt, &msg, 0)) < 0) { |
| dprintk("lockd: rpc_call returned error %d\n", -status); |
| switch (status) { |
| case -EPROTONOSUPPORT: |
| status = -EINVAL; |
| break; |
| case -ECONNREFUSED: |
| case -ETIMEDOUT: |
| case -ENOTCONN: |
| nlm_rebind_host(host); |
| status = -EAGAIN; |
| break; |
| case -ERESTARTSYS: |
| return signalled () ? -EINTR : status; |
| default: |
| break; |
| } |
| break; |
| } else |
| if (resp->status == nlm_lck_denied_grace_period) { |
| dprintk("lockd: server in grace period\n"); |
| if (argp->reclaim) { |
| printk(KERN_WARNING |
| "lockd: spurious grace period reject?!\n"); |
| return -ENOLCK; |
| } |
| } else { |
| if (!argp->reclaim) { |
| /* We appear to be out of the grace period */ |
| wake_up_all(&host->h_gracewait); |
| } |
| dprintk("lockd: server returns status %d\n", |
| ntohl(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. |
| */ |
| static struct rpc_task *__nlm_async_call(struct nlm_rqst *req, u32 proc, struct rpc_message *msg, const struct rpc_call_ops *tk_ops) |
| { |
| struct nlm_host *host = req->a_host; |
| struct rpc_clnt *clnt; |
| struct rpc_task_setup task_setup_data = { |
| .rpc_message = msg, |
| .callback_ops = tk_ops, |
| .callback_data = req, |
| .flags = RPC_TASK_ASYNC, |
| }; |
| |
| dprintk("lockd: call procedure %d on %s (async)\n", |
| (int)proc, host->h_name); |
| |
| /* If we have no RPC client yet, create one. */ |
| clnt = nlm_bind_host(host); |
| if (clnt == NULL) |
| goto out_err; |
| msg->rpc_proc = &clnt->cl_procinfo[proc]; |
| task_setup_data.rpc_client = clnt; |
| |
| /* bootstrap and kick off the async RPC call */ |
| return rpc_run_task(&task_setup_data); |
| out_err: |
| tk_ops->rpc_release(req); |
| 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; |
| } |
| |
| /* |
| * NLM asynchronous call. |
| */ |
| 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, |
| }; |
| return nlm_do_async_call(req, proc, &msg, tk_ops); |
| } |
| |
| 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, |
| }; |
| 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. |
| */ |
| static int nlmclnt_async_call(struct rpc_cred *cred, 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, |
| .rpc_cred = cred, |
| }; |
| 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; |
| } |
| |
| /* |
| * TEST for the presence of a conflicting lock |
| */ |
| static int |
| nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl) |
| { |
| int status; |
| |
| status = nlmclnt_call(nfs_file_cred(fl->fl_file), req, NLMPROC_TEST); |
| if (status < 0) |
| goto out; |
| |
| switch (req->a_res.status) { |
| case nlm_granted: |
| fl->fl_type = F_UNLCK; |
| break; |
| case nlm_lck_denied: |
| /* |
| * Report the conflicting lock back to the application. |
| */ |
| fl->fl_start = req->a_res.lock.fl.fl_start; |
| fl->fl_end = req->a_res.lock.fl.fl_end; |
| 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); |
| } |
| out: |
| nlmclnt_release_call(req); |
| return status; |
| } |
| |
| static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) |
| { |
| spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
| 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); |
| spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
| } |
| |
| static void nlmclnt_locks_release_private(struct file_lock *fl) |
| { |
| spin_lock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
| list_del(&fl->fl_u.nfs_fl.list); |
| spin_unlock(&fl->fl_u.nfs_fl.owner->host->h_lock); |
| nlm_put_lockowner(fl->fl_u.nfs_fl.owner); |
| } |
| |
| static const 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) |
| { |
| fl->fl_u.nfs_fl.state = 0; |
| fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); |
| INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list); |
| fl->fl_ops = &nlmclnt_lock_ops; |
| } |
| |
| static int 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(); |
| } |
| return res; |
| } |
| |
| /* |
| * 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 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) |
| goto out; |
| req->a_args.state = nsm_local_state; |
| |
| 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; |
| /* |
| * 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); |
| out_unblock: |
| nlmclnt_finish_block(block); |
| out: |
| nlmclnt_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", |
| ntohl(resp->status)); |
| /* What to do now? I'm out of my depth... */ |
| status = -ENOLCK; |
| out: |
| nlmclnt_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); |
| switch (task->tk_status) { |
| case -EACCES: |
| case -EIO: |
| goto die; |
| default: |
| 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: |
| 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, |
| .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(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; |
| nlmclnt_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; |
| 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, |
| .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", |
| ntohl(status)); |
| return -ENOLCK; |
| } |