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9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/slab.h>
12#include <linux/time.h>
13#include <linux/nfs_fs.h>
14#include <linux/sunrpc/addr.h>
15#include <linux/sunrpc/svc.h>
16#include <linux/lockd/lockd.h>
17#include <linux/kthread.h>
18
19#define NLMDBG_FACILITY NLMDBG_CLIENT
20
21
22
23
24static int reclaimer(void *ptr);
25
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32
33
34struct nlm_wait {
35 struct list_head b_list;
36 wait_queue_head_t b_wait;
37 struct nlm_host * b_host;
38 struct file_lock * b_lock;
39 unsigned short b_reclaim;
40 __be32 b_status;
41};
42
43static LIST_HEAD(nlm_blocked);
44static DEFINE_SPINLOCK(nlm_blocked_lock);
45
46
47
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51
52
53struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
54{
55 struct nlm_host *host;
56 u32 nlm_version = (nlm_init->nfs_version == 2) ? 1 : 4;
57 int status;
58
59 status = lockd_up(nlm_init->net);
60 if (status < 0)
61 return ERR_PTR(status);
62
63 host = nlmclnt_lookup_host(nlm_init->address, nlm_init->addrlen,
64 nlm_init->protocol, nlm_version,
65 nlm_init->hostname, nlm_init->noresvport,
66 nlm_init->net);
67 if (host == NULL) {
68 lockd_down(nlm_init->net);
69 return ERR_PTR(-ENOLCK);
70 }
71
72 return host;
73}
74EXPORT_SYMBOL_GPL(nlmclnt_init);
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78
79
80
81void nlmclnt_done(struct nlm_host *host)
82{
83 struct net *net = host->net;
84
85 nlmclnt_release_host(host);
86 lockd_down(net);
87}
88EXPORT_SYMBOL_GPL(nlmclnt_done);
89
90
91
92
93struct nlm_wait *nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl)
94{
95 struct nlm_wait *block;
96
97 block = kmalloc(sizeof(*block), GFP_KERNEL);
98 if (block != NULL) {
99 block->b_host = host;
100 block->b_lock = fl;
101 init_waitqueue_head(&block->b_wait);
102 block->b_status = nlm_lck_blocked;
103
104 spin_lock(&nlm_blocked_lock);
105 list_add(&block->b_list, &nlm_blocked);
106 spin_unlock(&nlm_blocked_lock);
107 }
108 return block;
109}
110
111void nlmclnt_finish_block(struct nlm_wait *block)
112{
113 if (block == NULL)
114 return;
115 spin_lock(&nlm_blocked_lock);
116 list_del(&block->b_list);
117 spin_unlock(&nlm_blocked_lock);
118 kfree(block);
119}
120
121
122
123
124int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
125{
126 long ret;
127
128
129
130
131 if (block == NULL)
132 return -EAGAIN;
133
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141
142 ret = wait_event_interruptible_timeout(block->b_wait,
143 block->b_status != nlm_lck_blocked,
144 timeout);
145 if (ret < 0)
146 return -ERESTARTSYS;
147
148 if (block->b_status == nlm_lck_denied_grace_period)
149 block->b_status = nlm_lck_blocked;
150 req->a_res.status = block->b_status;
151 return 0;
152}
153
154
155
156
157__be32 nlmclnt_grant(const struct sockaddr *addr, const struct nlm_lock *lock)
158{
159 const struct file_lock *fl = &lock->fl;
160 const struct nfs_fh *fh = &lock->fh;
161 struct nlm_wait *block;
162 __be32 res = nlm_lck_denied;
163
164
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167
168 spin_lock(&nlm_blocked_lock);
169 list_for_each_entry(block, &nlm_blocked, b_list) {
170 struct file_lock *fl_blocked = block->b_lock;
171
172 if (fl_blocked->fl_start != fl->fl_start)
173 continue;
174 if (fl_blocked->fl_end != fl->fl_end)
175 continue;
176
177
178
179
180 if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid)
181 continue;
182 if (!rpc_cmp_addr(nlm_addr(block->b_host), addr))
183 continue;
184 if (nfs_compare_fh(NFS_FH(file_inode(fl_blocked->fl_file)) ,fh) != 0)
185 continue;
186
187
188
189 block->b_status = nlm_granted;
190 wake_up(&block->b_wait);
191 res = nlm_granted;
192 }
193 spin_unlock(&nlm_blocked_lock);
194 return res;
195}
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205
206void
207nlmclnt_recovery(struct nlm_host *host)
208{
209 struct task_struct *task;
210
211 if (!host->h_reclaiming++) {
212 nlm_get_host(host);
213 task = kthread_run(reclaimer, host, "%s-reclaim", host->h_name);
214 if (IS_ERR(task))
215 printk(KERN_ERR "lockd: unable to spawn reclaimer "
216 "thread. Locks for %s won't be reclaimed! "
217 "(%ld)\n", host->h_name, PTR_ERR(task));
218 }
219}
220
221static int
222reclaimer(void *ptr)
223{
224 struct nlm_host *host = (struct nlm_host *) ptr;
225 struct nlm_wait *block;
226 struct nlm_rqst *req;
227 struct file_lock *fl, *next;
228 u32 nsmstate;
229 struct net *net = host->net;
230
231 req = kmalloc(sizeof(*req), GFP_KERNEL);
232 if (!req) {
233 printk(KERN_ERR "lockd: reclaimer unable to alloc memory."
234 " Locks for %s won't be reclaimed!\n",
235 host->h_name);
236 return 0;
237 }
238
239 allow_signal(SIGKILL);
240
241 down_write(&host->h_rwsem);
242 lockd_up(net);
243
244 dprintk("lockd: reclaiming locks for host %s\n", host->h_name);
245
246restart:
247 nsmstate = host->h_nsmstate;
248
249
250
251
252 host->h_nextrebind = jiffies;
253 nlm_rebind_host(host);
254
255
256 list_splice_init(&host->h_granted, &host->h_reclaim);
257 list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
258 list_del_init(&fl->fl_u.nfs_fl.list);
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264
265
266 if (signalled())
267 continue;
268 if (nlmclnt_reclaim(host, fl, req) != 0)
269 continue;
270 list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
271 if (host->h_nsmstate != nsmstate) {
272
273 goto restart;
274 }
275 }
276
277 host->h_reclaiming = 0;
278 up_write(&host->h_rwsem);
279 dprintk("NLM: done reclaiming locks for host %s\n", host->h_name);
280
281
282 spin_lock(&nlm_blocked_lock);
283 list_for_each_entry(block, &nlm_blocked, b_list) {
284 if (block->b_host == host) {
285 block->b_status = nlm_lck_denied_grace_period;
286 wake_up(&block->b_wait);
287 }
288 }
289 spin_unlock(&nlm_blocked_lock);
290
291
292 nlmclnt_release_host(host);
293 lockd_down(net);
294 kfree(req);
295 return 0;
296}
297