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 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 u32 b_status; /* grant callback status */
42 static LIST_HEAD(nlm_blocked);
48 nlmclnt_block(struct nlm_host *host, struct file_lock *fl, u32 *statp)
50 struct nlm_wait block, **head;
56 init_waitqueue_head(&block.b_wait);
57 block.b_status = NLM_LCK_BLOCKED;
58 list_add(&block.b_list, &nlm_blocked);
60 /* Remember pseudo nsm state */
61 pstate = host->h_state;
63 /* Go to sleep waiting for GRANT callback. Some servers seem
64 * to lose callbacks, however, so we're going to poll from
65 * time to time just to make sure.
67 * For now, the retry frequency is pretty high; normally
68 * a 1 minute timeout would do. See the comment before
69 * nlmclnt_lock for an explanation.
71 sleep_on_timeout(&block.b_wait, 30*HZ);
73 list_del(&block.b_list);
76 *statp = block.b_status;
80 /* Okay, we were interrupted. Cancel the pending request
81 * unless the server has rebooted.
83 if (pstate == host->h_state && (err = nlmclnt_cancel(host, fl)) < 0)
85 "lockd: CANCEL call failed (errno %d)\n", -err);
91 * The server lockd has called us back to tell us the lock was granted
94 nlmclnt_grant(struct nlm_lock *lock)
96 struct nlm_wait *block;
99 * Look up blocked request based on arguments.
100 * Warning: must not use cookie to match it!
102 list_for_each_entry(block, &nlm_blocked, b_list) {
103 if (nlm_compare_locks(block->b_lock, &lock->fl))
107 /* Ooops, no blocked request found. */
109 return nlm_lck_denied;
111 /* Alright, we found the lock. Set the return status and
112 * wake up the caller.
114 block->b_status = NLM_LCK_GRANTED;
115 wake_up(&block->b_wait);
121 * The following procedures deal with the recovery of locks after a
126 * Mark the locks for reclaiming.
127 * FIXME: In 2.5 we don't want to iterate through any global file_lock_list.
128 * Maintain NLM lock reclaiming lists in the nlm_host instead.
131 void nlmclnt_mark_reclaim(struct nlm_host *host)
133 struct file_lock *fl;
135 struct list_head *tmp;
137 list_for_each(tmp, &file_lock_list) {
138 fl = list_entry(tmp, struct file_lock, fl_link);
140 inode = fl->fl_file->f_dentry->d_inode;
141 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
143 if (fl->fl_u.nfs_fl.owner->host != host)
145 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_GRANTED))
147 fl->fl_u.nfs_fl.flags |= NFS_LCK_RECLAIM;
152 * Someone has sent us an SM_NOTIFY. Ensure we bind to the new port number,
153 * that we mark locks for reclaiming, and that we bump the pseudo NSM state.
156 void nlmclnt_prepare_reclaim(struct nlm_host *host, u32 newstate)
158 host->h_monitored = 0;
159 host->h_nsmstate = newstate;
161 host->h_nextrebind = 0;
162 nlm_rebind_host(host);
163 nlmclnt_mark_reclaim(host);
164 dprintk("NLM: reclaiming locks for host %s", host->h_name);
168 * Reclaim all locks on server host. We do this by spawning a separate
172 nlmclnt_recovery(struct nlm_host *host, u32 newstate)
174 if (host->h_reclaiming++) {
175 if (host->h_nsmstate == newstate)
177 nlmclnt_prepare_reclaim(host, newstate);
179 nlmclnt_prepare_reclaim(host, newstate);
181 __module_get(THIS_MODULE);
182 if (kernel_thread(reclaimer, host, CLONE_KERNEL) < 0)
183 module_put(THIS_MODULE);
190 struct nlm_host *host = (struct nlm_host *) ptr;
191 struct nlm_wait *block;
192 struct list_head *tmp;
193 struct file_lock *fl;
196 daemonize("%s-reclaim", host->h_name);
197 allow_signal(SIGKILL);
199 /* This one ensures that our parent doesn't terminate while the
200 * reclaim is in progress */
204 /* First, reclaim all locks that have been marked. */
206 list_for_each(tmp, &file_lock_list) {
207 fl = list_entry(tmp, struct file_lock, fl_link);
209 inode = fl->fl_file->f_dentry->d_inode;
210 if (inode->i_sb->s_magic != NFS_SUPER_MAGIC)
212 if (fl->fl_u.nfs_fl.owner->host != host)
214 if (!(fl->fl_u.nfs_fl.flags & NFS_LCK_RECLAIM))
217 fl->fl_u.nfs_fl.flags &= ~NFS_LCK_RECLAIM;
218 nlmclnt_reclaim(host, fl);
224 host->h_reclaiming = 0;
226 /* Now, wake up all processes that sleep on a blocked lock */
227 list_for_each_entry(block, &nlm_blocked, b_list) {
228 if (block->b_host == host) {
229 block->b_status = NLM_LCK_DENIED_GRACE_PERIOD;
230 wake_up(&block->b_wait);
234 /* Release host handle after use */
235 nlm_release_host(host);
238 module_put_and_exit(0);