wusb: disable verification of the key generation algorithms
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / lockd / clntlock.c
blob8307dd64bf46ca746d9c973f209626de49627d17
1 /*
2 * linux/fs/lockd/clntlock.c
4 * Lock handling for the client side NLM implementation
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7 */
9 #include <linux/module.h>
10 #include <linux/types.h>
11 #include <linux/time.h>
12 #include <linux/nfs_fs.h>
13 #include <linux/sunrpc/clnt.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/lockd/lockd.h>
16 #include <linux/smp_lock.h>
18 #define NLMDBG_FACILITY NLMDBG_CLIENT
21 * Local function prototypes
23 static int reclaimer(void *ptr);
26 * The following functions handle blocking and granting from the
27 * client perspective.
31 * This is the representation of a blocked client lock.
33 struct nlm_wait {
34 struct list_head b_list; /* linked list */
35 wait_queue_head_t b_wait; /* where to wait on */
36 struct nlm_host * b_host;
37 struct file_lock * b_lock; /* local file lock */
38 unsigned short b_reclaim; /* got to reclaim lock */
39 __be32 b_status; /* grant callback status */
42 static LIST_HEAD(nlm_blocked);
44 /**
45 * nlmclnt_init - Set up per-NFS mount point lockd data structures
46 * @nlm_init: pointer to arguments structure
48 * Returns pointer to an appropriate nlm_host struct,
49 * or an ERR_PTR value.
51 struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
53 struct nlm_host *host;
54 u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
55 int status;
57 status = lockd_up();
58 if (status < 0)
59 return ERR_PTR(status);
61 host = nlmclnt_lookup_host(nlm_init->address, nlm_init->addrlen,
62 nlm_init->protocol, nlm_version,
63 nlm_init->hostname);
64 if (host == NULL) {
65 lockd_down();
66 return ERR_PTR(-ENOLCK);
69 return host;
71 EXPORT_SYMBOL_GPL(nlmclnt_init);
73 /**
74 * nlmclnt_done - Release resources allocated by nlmclnt_init()
75 * @host: nlm_host structure reserved by nlmclnt_init()
78 void nlmclnt_done(struct nlm_host *host)
80 nlm_release_host(host);
81 lockd_down();
83 EXPORT_SYMBOL_GPL(nlmclnt_done);
86 * Queue up a lock for blocking so that the GRANTED request can see it
88 struct nlm_wait *nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl)
90 struct nlm_wait *block;
92 block = kmalloc(sizeof(*block), GFP_KERNEL);
93 if (block != NULL) {
94 block->b_host = host;
95 block->b_lock = fl;
96 init_waitqueue_head(&block->b_wait);
97 block->b_status = nlm_lck_blocked;
98 list_add(&block->b_list, &nlm_blocked);
100 return block;
103 void nlmclnt_finish_block(struct nlm_wait *block)
105 if (block == NULL)
106 return;
107 list_del(&block->b_list);
108 kfree(block);
112 * Block on a lock
114 int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
116 long ret;
118 /* A borken server might ask us to block even if we didn't
119 * request it. Just say no!
121 if (block == NULL)
122 return -EAGAIN;
124 /* Go to sleep waiting for GRANT callback. Some servers seem
125 * to lose callbacks, however, so we're going to poll from
126 * time to time just to make sure.
128 * For now, the retry frequency is pretty high; normally
129 * a 1 minute timeout would do. See the comment before
130 * nlmclnt_lock for an explanation.
132 ret = wait_event_interruptible_timeout(block->b_wait,
133 block->b_status != nlm_lck_blocked,
134 timeout);
135 if (ret < 0)
136 return -ERESTARTSYS;
137 req->a_res.status = block->b_status;
138 return 0;
142 * The server lockd has called us back to tell us the lock was granted
144 __be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock)
146 const struct file_lock *fl = &lock->fl;
147 const struct nfs_fh *fh = &lock->fh;
148 struct nlm_wait *block;
149 __be32 res = nlm_lck_denied;
152 * Look up blocked request based on arguments.
153 * Warning: must not use cookie to match it!
155 list_for_each_entry(block, &nlm_blocked, b_list) {
156 struct file_lock *fl_blocked = block->b_lock;
158 if (fl_blocked->fl_start != fl->fl_start)
159 continue;
160 if (fl_blocked->fl_end != fl->fl_end)
161 continue;
163 * Careful! The NLM server will return the 32-bit "pid" that
164 * we put on the wire: in this case the lockowner "pid".
166 if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
167 continue;
168 if (!nlm_cmp_addr(nlm_addr(block->b_host), addr))
169 continue;
170 if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0)
171 continue;
172 /* Alright, we found a lock. Set the return status
173 * and wake up the caller
175 block->b_status = nlm_granted;
176 wake_up(&block->b_wait);
177 res = nlm_granted;
179 return res;
183 * The following procedures deal with the recovery of locks after a
184 * server crash.
188 * Reclaim all locks on server host. We do this by spawning a separate
189 * reclaimer thread.
191 void
192 nlmclnt_recovery(struct nlm_host *host)
194 if (!host->h_reclaiming++) {
195 nlm_get_host(host);
196 __module_get(THIS_MODULE);
197 if (kernel_thread(reclaimer, host, CLONE_FS | CLONE_FILES) < 0)
198 module_put(THIS_MODULE);
202 static int
203 reclaimer(void *ptr)
205 struct nlm_host *host = (struct nlm_host *) ptr;
206 struct nlm_wait *block;
207 struct file_lock *fl, *next;
208 u32 nsmstate;
210 daemonize("%s-reclaim", host->h_name);
211 allow_signal(SIGKILL);
213 down_write(&host->h_rwsem);
215 /* This one ensures that our parent doesn't terminate while the
216 * reclaim is in progress */
217 lock_kernel();
218 lockd_up(); /* note: this cannot fail as lockd is already running */
220 dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
222 restart:
223 nsmstate = host->h_nsmstate;
225 /* Force a portmap getport - the peer's lockd will
226 * most likely end up on a different port.
228 host->h_nextrebind = jiffies;
229 nlm_rebind_host(host);
231 /* First, reclaim all locks that have been granted. */
232 list_splice_init(&host->h_granted, &host->h_reclaim);
233 list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
234 list_del_init(&fl->fl_u.nfs_fl.list);
236 /* Why are we leaking memory here? --okir */
237 if (signalled())
238 continue;
239 if (nlmclnt_reclaim(host, fl) != 0)
240 continue;
241 list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
242 if (host->h_nsmstate != nsmstate) {
243 /* Argh! The server rebooted again! */
244 goto restart;
248 host->h_reclaiming = 0;
249 up_write(&host->h_rwsem);
250 dprintk("NLM: done reclaiming locks for host %s\n", host->h_name);
252 /* Now, wake up all processes that sleep on a blocked lock */
253 list_for_each_entry(block, &nlm_blocked, b_list) {
254 if (block->b_host == host) {
255 block->b_status = nlm_lck_denied_grace_period;
256 wake_up(&block->b_wait);
260 /* Release host handle after use */
261 nlm_release_host(host);
262 lockd_down();
263 unlock_kernel();
264 module_put_and_exit(0);