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>
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
31 * This is the representation of a blocked client lock.
34 struct nlm_wait * b_next; /* 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 u32 b_status; /* grant callback status */
42 static struct nlm_wait * nlm_blocked;
48 nlmclnt_block(struct nlm_host *host, struct file_lock *fl, u32 *statp)
50 struct nlm_wait block, **head;
57 block.b_status = NLM_LCK_BLOCKED;
58 init_waitqueue_entry(&__wait, current);
59 init_waitqueue_head(&block.b_wait);
60 add_wait_queue(&block.b_wait, &__wait);
62 block.b_next = nlm_blocked;
66 /* Remember pseudo nsm state */
67 pstate = host->h_state;
69 /* Go to sleep waiting for GRANT callback. Some servers seem
70 * to lose callbacks, however, so we're going to poll from
71 * time to time just to make sure.
73 * For now, the retry frequency is pretty high; normally
74 * a 1 minute timeout would do. See the comment before
75 * nlmclnt_lock for an explanation.
77 set_current_state(TASK_UNINTERRUPTIBLE);
78 schedule_timeout(30*HZ);
80 for (head = &nlm_blocked; *head; head = &(*head)->b_next) {
81 if (*head == &block) {
86 remove_wait_queue(&block.b_wait, &__wait);
89 *statp = block.b_status;
93 /* Okay, we were interrupted. Cancel the pending request
94 * unless the server has rebooted.
96 if (pstate == host->h_state && (err = nlmclnt_cancel(host, fl)) < 0)
98 "lockd: CANCEL call failed (errno %d)\n", -err);
104 * The server lockd has called us back to tell us the lock was granted
107 nlmclnt_grant(struct nlm_lock *lock)
109 struct nlm_wait *block;
112 * Look up blocked request based on arguments.
113 * Warning: must not use cookie to match it!
115 for (block = nlm_blocked; block; block = block->b_next) {
116 if (nlm_compare_locks(block->b_lock, &lock->fl))
120 /* Ooops, no blocked request found. */
122 return nlm_lck_denied;
124 /* Alright, we found the lock. Set the return status and
125 * wake up the caller.
127 block->b_status = NLM_LCK_GRANTED;
128 wake_up(&block->b_wait);
134 * The following procedures deal with the recovery of locks after a
139 * Mark the locks for reclaiming.
140 * FIXME: In 2.5 we don't want to iterate through any global file_lock_list.
141 * Maintain NLM lock reclaiming lists in the nlm_host instead.
144 void nlmclnt_mark_reclaim(struct nlm_host *host)
146 struct file_lock *fl;
148 struct list_head *tmp;
150 list_for_each(tmp, &file_lock_list) {
151 fl = list_entry(tmp, struct file_lock, fl_link);
153 inode = fl->fl_file->f_dentry->d_inode;
154 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
156 if (fl->fl_u.nfs_fl.owner->host != host)
158 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED))
160 fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM;
165 * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number,
166 * that we mark locks for reclaiming, and that we bump the pseudo NSM state.
169 void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate)
171 host->h_monitored = 0;
172 host->h_nsmstate = newstate;
174 host->h_nextrebind = 0;
175 nlm_rebind_host(host);
176 nlmclnt_mark_reclaim(host);
177 dprintk("NLM: reclaiming locks for host %s\n", host->h_name);
181 * Reclaim all locks on server host. We do this by spawning a separate
185 nlmclnt_recovery(struct nlm_host *host, u32 newstate)
187 if (host->h_reclaiming++) {
188 if (host->h_nsmstate == newstate)
190 nlmclnt_prepare_reclaim(host, newstate);
192 nlmclnt_prepare_reclaim(host, newstate);
194 __module_get(THIS_MODULE);
195 if (kernel_thread(reclaimer, host, CLONE_KERNEL) < 0)
196 module_put(THIS_MODULE);
203 struct nlm_host *host = (struct nlm_host *) ptr;
204 struct nlm_wait *block;
205 struct list_head *tmp;
206 struct file_lock *fl;
209 daemonize("%s-reclaim", host->h_name);
210 allow_signal(SIGKILL);
212 /* This one ensures that our parent doesn't terminate while the
213 * reclaim is in progress */
217 /* First, reclaim all locks that have been marked. */
219 list_for_each(tmp, &file_lock_list) {
220 fl = list_entry(tmp, struct file_lock, fl_link);
222 inode = fl->fl_file->f_dentry->d_inode;
223 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
225 if (fl->fl_u.nfs_fl.owner->host != host)
227 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM))
230 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM;
231 nlmclnt_reclaim(host, fl);
237 host->h_reclaiming = 0;
239 /* Now, wake up all processes that sleep on a blocked lock */
240 for (block = nlm_blocked; block; block = block->b_next) {
241 if (block->b_host == host) {
242 block->b_status = NLM_LCK_DENIED_GRACE_PERIOD;
243 wake_up(&block->b_wait);
247 /* Release host handle after use */
248 nlm_release_host(host);
251 module_put_and_exit(0);