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 #define __KERNEL_SYSCALLS__
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/sched.h>
14 #include <linux/nfs_fs.h>
15 #include <linux/unistd.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/sunrpc/svc.h>
18 #include <linux/lockd/lockd.h>
19 #include <linux/smp_lock.h>
21 #define NLMDBG_FACILITY NLMDBG_CLIENT
24 * Local function prototypes
26 static int reclaimer(void *ptr);
29 * The following functions handle blocking and granting from the
34 * This is the representation of a blocked client lock.
37 struct nlm_wait * b_next; /* linked list */
38 wait_queue_head_t b_wait; /* where to wait on */
39 struct nlm_host * b_host;
40 struct file_lock * b_lock; /* local file lock */
41 unsigned short b_reclaim; /* got to reclaim lock */
42 u32 b_status; /* grant callback status */
45 static struct nlm_wait * nlm_blocked;
51 nlmclnt_block(struct nlm_host *host, struct file_lock *fl, u32 *statp)
53 struct nlm_wait block, **head;
59 init_waitqueue_head(&block.b_wait);
60 block.b_status = NLM_LCK_BLOCKED;
61 block.b_next = nlm_blocked;
64 /* Remember pseudo nsm state */
65 pstate = host->h_state;
67 /* Go to sleep waiting for GRANT callback. Some servers seem
68 * to lose callbacks, however, so we're going to poll from
69 * time to time just to make sure.
71 * For now, the retry frequency is pretty high; normally
72 * a 1 minute timeout would do. See the comment before
73 * nlmclnt_lock for an explanation.
75 sleep_on_timeout(&block.b_wait, 30*HZ);
77 for (head = &nlm_blocked; *head; head = &(*head)->b_next) {
78 if (*head == &block) {
85 *statp = block.b_status;
89 /* Okay, we were interrupted. Cancel the pending request
90 * unless the server has rebooted.
92 if (pstate == host->h_state && (err = nlmclnt_cancel(host, fl)) < 0)
94 "lockd: CANCEL call failed (errno %d)\n", -err);
100 * The server lockd has called us back to tell us the lock was granted
103 nlmclnt_grant(struct nlm_lock *lock)
105 struct nlm_wait *block;
108 * Look up blocked request based on arguments.
109 * Warning: must not use cookie to match it!
111 for (block = nlm_blocked; block; block = block->b_next) {
112 if (nlm_compare_locks(block->b_lock, &lock->fl))
116 /* Ooops, no blocked request found. */
118 return nlm_lck_denied;
120 /* Alright, we found the lock. Set the return status and
121 * wake up the caller.
123 block->b_status = NLM_LCK_GRANTED;
124 wake_up(&block->b_wait);
130 * The following procedures deal with the recovery of locks after a
135 * Mark the locks for reclaiming.
136 * FIXME: In 2.5 we don't want to iterate through any global file_lock_list.
137 * Maintain NLM lock reclaiming lists in the nlm_host instead.
140 void nlmclnt_mark_reclaim(struct nlm_host *host)
142 struct file_lock *fl;
144 struct list_head *tmp;
146 list_for_each(tmp, &file_lock_list) {
147 fl = list_entry(tmp, struct file_lock, fl_link);
149 inode = fl->fl_file->f_dentry->d_inode;
150 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
152 if (fl->fl_u.nfs_fl.host != host)
154 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED))
156 fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM;
161 * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number,
162 * that we mark locks for reclaiming, and that we bump the pseudo NSM state.
165 void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate)
167 host->h_monitored = 0;
168 host->h_nsmstate = newstate;
170 host->h_nextrebind = 0;
171 nlm_rebind_host(host);
172 nlmclnt_mark_reclaim(host);
173 dprintk("NLM: reclaiming locks for host %s", host->h_name);
177 * Reclaim all locks on server host. We do this by spawning a separate
181 nlmclnt_recovery(struct nlm_host *host, u32 newstate)
183 if (host->h_reclaiming++) {
184 if (host->h_nsmstate == newstate)
186 nlmclnt_prepare_reclaim(host, newstate);
188 nlmclnt_prepare_reclaim(host, newstate);
191 if (kernel_thread(reclaimer, host, CLONE_SIGNAL) < 0)
199 struct nlm_host *host = (struct nlm_host *) ptr;
200 struct nlm_wait *block;
201 struct list_head *tmp;
202 struct file_lock *fl;
207 snprintf(current->comm, sizeof(current->comm),
211 /* This one ensures that our parent doesn't terminate while the
212 * reclaim is in progress */
216 /* First, reclaim all locks that have been marked. */
218 list_for_each(tmp, &file_lock_list) {
219 fl = list_entry(tmp, struct file_lock, fl_link);
221 inode = fl->fl_file->f_dentry->d_inode;
222 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
224 if (fl->fl_u.nfs_fl.host != host)
226 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM))
229 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM;
230 nlmclnt_reclaim(host, fl);
236 host->h_reclaiming = 0;
237 wake_up(&host->h_gracewait);
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);