Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/fs/lockd/clntlock.c | |
3 | * | |
4 | * Lock handling for the client side NLM implementation | |
5 | * | |
6 | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | |
7 | */ | |
8 | ||
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> | |
17 | ||
18 | #define NLMDBG_FACILITY NLMDBG_CLIENT | |
19 | ||
20 | /* | |
21 | * Local function prototypes | |
22 | */ | |
23 | static int reclaimer(void *ptr); | |
24 | ||
25 | /* | |
26 | * The following functions handle blocking and granting from the | |
27 | * client perspective. | |
28 | */ | |
29 | ||
30 | /* | |
31 | * This is the representation of a blocked client lock. | |
32 | */ | |
33 | struct nlm_wait { | |
4f15e2b1 | 34 | struct list_head b_list; /* linked list */ |
1da177e4 LT |
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 */ | |
e8c5c045 | 39 | __be32 b_status; /* grant callback status */ |
1da177e4 LT |
40 | }; |
41 | ||
4f15e2b1 | 42 | static LIST_HEAD(nlm_blocked); |
1da177e4 | 43 | |
52c4044d CL |
44 | /** |
45 | * nlmclnt_init - Set up per-NFS mount point lockd data structures | |
46 | * @server_name: server's hostname | |
47 | * @server_address: server's network address | |
48 | * @server_addrlen: length of server's address | |
49 | * @protocol: transport protocol lockd should use | |
50 | * @nfs_version: NFS protocol version for this mount point | |
51 | * | |
52 | * Returns pointer to an appropriate nlm_host struct, | |
53 | * or an ERR_PTR value. | |
54 | */ | |
55 | struct nlm_host *nlmclnt_init(const char *server_name, | |
56 | const struct sockaddr *server_address, | |
57 | size_t server_addrlen, | |
58 | unsigned short protocol, u32 nfs_version) | |
59 | { | |
60 | struct nlm_host *host; | |
61 | u32 nlm_version = (nfs_version == 2) ? 1 : 4; | |
62 | int status; | |
63 | ||
64 | status = lockd_up(protocol); | |
65 | if (status < 0) | |
66 | return ERR_PTR(status); | |
67 | ||
68 | host = nlmclnt_lookup_host((struct sockaddr_in *)server_address, | |
69 | protocol, nlm_version, | |
70 | server_name, strlen(server_name)); | |
71 | if (host == NULL) { | |
72 | lockd_down(); | |
73 | return ERR_PTR(-ENOLCK); | |
74 | } | |
75 | ||
76 | return host; | |
77 | } | |
78 | EXPORT_SYMBOL_GPL(nlmclnt_init); | |
79 | ||
80 | /** | |
81 | * nlmclnt_done - Release resources allocated by nlmclnt_init() | |
82 | * @host: nlm_host structure reserved by nlmclnt_init() | |
83 | * | |
84 | */ | |
85 | void nlmclnt_done(struct nlm_host *host) | |
86 | { | |
87 | nlm_release_host(host); | |
88 | lockd_down(); | |
89 | } | |
90 | EXPORT_SYMBOL_GPL(nlmclnt_done); | |
91 | ||
1da177e4 | 92 | /* |
ecdbf769 | 93 | * Queue up a lock for blocking so that the GRANTED request can see it |
1da177e4 | 94 | */ |
3a649b88 | 95 | struct nlm_wait *nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl) |
ecdbf769 TM |
96 | { |
97 | struct nlm_wait *block; | |
98 | ||
ecdbf769 | 99 | block = kmalloc(sizeof(*block), GFP_KERNEL); |
3a649b88 TM |
100 | if (block != NULL) { |
101 | block->b_host = host; | |
102 | block->b_lock = fl; | |
103 | init_waitqueue_head(&block->b_wait); | |
e8c5c045 | 104 | block->b_status = nlm_lck_blocked; |
3a649b88 TM |
105 | list_add(&block->b_list, &nlm_blocked); |
106 | } | |
107 | return block; | |
ecdbf769 TM |
108 | } |
109 | ||
3a649b88 | 110 | void nlmclnt_finish_block(struct nlm_wait *block) |
1da177e4 | 111 | { |
ecdbf769 TM |
112 | if (block == NULL) |
113 | return; | |
ecdbf769 TM |
114 | list_del(&block->b_list); |
115 | kfree(block); | |
116 | } | |
1da177e4 | 117 | |
ecdbf769 TM |
118 | /* |
119 | * Block on a lock | |
120 | */ | |
3a649b88 | 121 | int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout) |
ecdbf769 | 122 | { |
ecdbf769 | 123 | long ret; |
1da177e4 | 124 | |
ecdbf769 TM |
125 | /* A borken server might ask us to block even if we didn't |
126 | * request it. Just say no! | |
127 | */ | |
3a649b88 | 128 | if (block == NULL) |
ecdbf769 | 129 | return -EAGAIN; |
1da177e4 LT |
130 | |
131 | /* Go to sleep waiting for GRANT callback. Some servers seem | |
132 | * to lose callbacks, however, so we're going to poll from | |
133 | * time to time just to make sure. | |
134 | * | |
135 | * For now, the retry frequency is pretty high; normally | |
136 | * a 1 minute timeout would do. See the comment before | |
137 | * nlmclnt_lock for an explanation. | |
138 | */ | |
ecdbf769 | 139 | ret = wait_event_interruptible_timeout(block->b_wait, |
e8c5c045 | 140 | block->b_status != nlm_lck_blocked, |
ecdbf769 | 141 | timeout); |
3a649b88 TM |
142 | if (ret < 0) |
143 | return -ERESTARTSYS; | |
144 | req->a_res.status = block->b_status; | |
145 | return 0; | |
1da177e4 LT |
146 | } |
147 | ||
148 | /* | |
149 | * The server lockd has called us back to tell us the lock was granted | |
150 | */ | |
52921e02 | 151 | __be32 nlmclnt_grant(const struct sockaddr_in *addr, const struct nlm_lock *lock) |
1da177e4 | 152 | { |
5ac5f9d1 TM |
153 | const struct file_lock *fl = &lock->fl; |
154 | const struct nfs_fh *fh = &lock->fh; | |
1da177e4 | 155 | struct nlm_wait *block; |
52921e02 | 156 | __be32 res = nlm_lck_denied; |
1da177e4 LT |
157 | |
158 | /* | |
159 | * Look up blocked request based on arguments. | |
160 | * Warning: must not use cookie to match it! | |
161 | */ | |
4f15e2b1 | 162 | list_for_each_entry(block, &nlm_blocked, b_list) { |
5ac5f9d1 TM |
163 | struct file_lock *fl_blocked = block->b_lock; |
164 | ||
7bab377f TM |
165 | if (fl_blocked->fl_start != fl->fl_start) |
166 | continue; | |
167 | if (fl_blocked->fl_end != fl->fl_end) | |
168 | continue; | |
169 | /* | |
170 | * Careful! The NLM server will return the 32-bit "pid" that | |
171 | * we put on the wire: in this case the lockowner "pid". | |
172 | */ | |
173 | if (fl_blocked->fl_u.nfs_fl.owner->pid != lock->svid) | |
5ac5f9d1 TM |
174 | continue; |
175 | if (!nlm_cmp_addr(&block->b_host->h_addr, addr)) | |
176 | continue; | |
225a719f | 177 | if (nfs_compare_fh(NFS_FH(fl_blocked->fl_file->f_path.dentry->d_inode) ,fh) != 0) |
5ac5f9d1 TM |
178 | continue; |
179 | /* Alright, we found a lock. Set the return status | |
180 | * and wake up the caller | |
181 | */ | |
e8c5c045 | 182 | block->b_status = nlm_granted; |
5ac5f9d1 TM |
183 | wake_up(&block->b_wait); |
184 | res = nlm_granted; | |
1da177e4 | 185 | } |
ecdbf769 | 186 | return res; |
1da177e4 LT |
187 | } |
188 | ||
189 | /* | |
190 | * The following procedures deal with the recovery of locks after a | |
191 | * server crash. | |
192 | */ | |
193 | ||
1da177e4 LT |
194 | /* |
195 | * Reclaim all locks on server host. We do this by spawning a separate | |
196 | * reclaimer thread. | |
197 | */ | |
198 | void | |
5c8dd29c | 199 | nlmclnt_recovery(struct nlm_host *host) |
1da177e4 | 200 | { |
28df955a | 201 | if (!host->h_reclaiming++) { |
1da177e4 LT |
202 | nlm_get_host(host); |
203 | __module_get(THIS_MODULE); | |
550facd1 | 204 | if (kernel_thread(reclaimer, host, CLONE_FS | CLONE_FILES) < 0) |
1da177e4 LT |
205 | module_put(THIS_MODULE); |
206 | } | |
207 | } | |
208 | ||
209 | static int | |
210 | reclaimer(void *ptr) | |
211 | { | |
212 | struct nlm_host *host = (struct nlm_host *) ptr; | |
213 | struct nlm_wait *block; | |
26bcbf96 | 214 | struct file_lock *fl, *next; |
28df955a | 215 | u32 nsmstate; |
1da177e4 LT |
216 | |
217 | daemonize("%s-reclaim", host->h_name); | |
218 | allow_signal(SIGKILL); | |
219 | ||
5c8dd29c OK |
220 | down_write(&host->h_rwsem); |
221 | ||
1da177e4 LT |
222 | /* This one ensures that our parent doesn't terminate while the |
223 | * reclaim is in progress */ | |
224 | lock_kernel(); | |
4a3ae42d | 225 | lockd_up(0); /* note: this cannot fail as lockd is already running */ |
1da177e4 | 226 | |
d019bcf0 | 227 | dprintk("lockd: reclaiming locks for host %s\n", host->h_name); |
5c8dd29c | 228 | |
1da177e4 | 229 | restart: |
28df955a | 230 | nsmstate = host->h_nsmstate; |
5c8dd29c OK |
231 | |
232 | /* Force a portmap getport - the peer's lockd will | |
233 | * most likely end up on a different port. | |
234 | */ | |
0ade060e | 235 | host->h_nextrebind = jiffies; |
5c8dd29c OK |
236 | nlm_rebind_host(host); |
237 | ||
238 | /* First, reclaim all locks that have been granted. */ | |
239 | list_splice_init(&host->h_granted, &host->h_reclaim); | |
26bcbf96 | 240 | list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) { |
4c060b53 | 241 | list_del_init(&fl->fl_u.nfs_fl.list); |
1da177e4 | 242 | |
5c8dd29c | 243 | /* Why are we leaking memory here? --okir */ |
1da177e4 | 244 | if (signalled()) |
4c060b53 | 245 | continue; |
28df955a TM |
246 | if (nlmclnt_reclaim(host, fl) != 0) |
247 | continue; | |
248 | list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted); | |
249 | if (host->h_nsmstate != nsmstate) { | |
250 | /* Argh! The server rebooted again! */ | |
28df955a TM |
251 | goto restart; |
252 | } | |
1da177e4 | 253 | } |
5c8dd29c OK |
254 | |
255 | host->h_reclaiming = 0; | |
256 | up_write(&host->h_rwsem); | |
d019bcf0 | 257 | dprintk("NLM: done reclaiming locks for host %s\n", host->h_name); |
1da177e4 LT |
258 | |
259 | /* Now, wake up all processes that sleep on a blocked lock */ | |
4f15e2b1 | 260 | list_for_each_entry(block, &nlm_blocked, b_list) { |
1da177e4 | 261 | if (block->b_host == host) { |
e8c5c045 | 262 | block->b_status = nlm_lck_denied_grace_period; |
1da177e4 LT |
263 | wake_up(&block->b_wait); |
264 | } | |
265 | } | |
266 | ||
267 | /* Release host handle after use */ | |
268 | nlm_release_host(host); | |
269 | lockd_down(); | |
270 | unlock_kernel(); | |
271 | module_put_and_exit(0); | |
272 | } |