xref: /linux/net/ceph/cls_lock_client.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 #include <linux/ceph/ceph_debug.h>
2 
3 #include <linux/types.h>
4 #include <linux/slab.h>
5 
6 #include <linux/ceph/cls_lock_client.h>
7 #include <linux/ceph/decode.h>
8 
9 /**
10  * ceph_cls_lock - grab rados lock for object
11  * @oid, @oloc: object to lock
12  * @lock_name: the name of the lock
13  * @type: lock type (CEPH_CLS_LOCK_EXCLUSIVE or CEPH_CLS_LOCK_SHARED)
14  * @cookie: user-defined identifier for this instance of the lock
15  * @tag: user-defined tag
16  * @desc: user-defined lock description
17  * @flags: lock flags
18  *
19  * All operations on the same lock should use the same tag.
20  */
21 int ceph_cls_lock(struct ceph_osd_client *osdc,
22 		  struct ceph_object_id *oid,
23 		  struct ceph_object_locator *oloc,
24 		  char *lock_name, u8 type, char *cookie,
25 		  char *tag, char *desc, u8 flags)
26 {
27 	int lock_op_buf_size;
28 	int name_len = strlen(lock_name);
29 	int cookie_len = strlen(cookie);
30 	int tag_len = strlen(tag);
31 	int desc_len = strlen(desc);
32 	void *p, *end;
33 	struct page *lock_op_page;
34 	struct timespec mtime;
35 	int ret;
36 
37 	lock_op_buf_size = name_len + sizeof(__le32) +
38 			   cookie_len + sizeof(__le32) +
39 			   tag_len + sizeof(__le32) +
40 			   desc_len + sizeof(__le32) +
41 			   sizeof(struct ceph_timespec) +
42 			   /* flag and type */
43 			   sizeof(u8) + sizeof(u8) +
44 			   CEPH_ENCODING_START_BLK_LEN;
45 	if (lock_op_buf_size > PAGE_SIZE)
46 		return -E2BIG;
47 
48 	lock_op_page = alloc_page(GFP_NOIO);
49 	if (!lock_op_page)
50 		return -ENOMEM;
51 
52 	p = page_address(lock_op_page);
53 	end = p + lock_op_buf_size;
54 
55 	/* encode cls_lock_lock_op struct */
56 	ceph_start_encoding(&p, 1, 1,
57 			    lock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
58 	ceph_encode_string(&p, end, lock_name, name_len);
59 	ceph_encode_8(&p, type);
60 	ceph_encode_string(&p, end, cookie, cookie_len);
61 	ceph_encode_string(&p, end, tag, tag_len);
62 	ceph_encode_string(&p, end, desc, desc_len);
63 	/* only support infinite duration */
64 	memset(&mtime, 0, sizeof(mtime));
65 	ceph_encode_timespec(p, &mtime);
66 	p += sizeof(struct ceph_timespec);
67 	ceph_encode_8(&p, flags);
68 
69 	dout("%s lock_name %s type %d cookie %s tag %s desc %s flags 0x%x\n",
70 	     __func__, lock_name, type, cookie, tag, desc, flags);
71 	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "lock",
72 			     CEPH_OSD_FLAG_WRITE, lock_op_page,
73 			     lock_op_buf_size, NULL, NULL);
74 
75 	dout("%s: status %d\n", __func__, ret);
76 	__free_page(lock_op_page);
77 	return ret;
78 }
79 EXPORT_SYMBOL(ceph_cls_lock);
80 
81 /**
82  * ceph_cls_unlock - release rados lock for object
83  * @oid, @oloc: object to lock
84  * @lock_name: the name of the lock
85  * @cookie: user-defined identifier for this instance of the lock
86  */
87 int ceph_cls_unlock(struct ceph_osd_client *osdc,
88 		    struct ceph_object_id *oid,
89 		    struct ceph_object_locator *oloc,
90 		    char *lock_name, char *cookie)
91 {
92 	int unlock_op_buf_size;
93 	int name_len = strlen(lock_name);
94 	int cookie_len = strlen(cookie);
95 	void *p, *end;
96 	struct page *unlock_op_page;
97 	int ret;
98 
99 	unlock_op_buf_size = name_len + sizeof(__le32) +
100 			     cookie_len + sizeof(__le32) +
101 			     CEPH_ENCODING_START_BLK_LEN;
102 	if (unlock_op_buf_size > PAGE_SIZE)
103 		return -E2BIG;
104 
105 	unlock_op_page = alloc_page(GFP_NOIO);
106 	if (!unlock_op_page)
107 		return -ENOMEM;
108 
109 	p = page_address(unlock_op_page);
110 	end = p + unlock_op_buf_size;
111 
112 	/* encode cls_lock_unlock_op struct */
113 	ceph_start_encoding(&p, 1, 1,
114 			    unlock_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
115 	ceph_encode_string(&p, end, lock_name, name_len);
116 	ceph_encode_string(&p, end, cookie, cookie_len);
117 
118 	dout("%s lock_name %s cookie %s\n", __func__, lock_name, cookie);
119 	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "unlock",
120 			     CEPH_OSD_FLAG_WRITE, unlock_op_page,
121 			     unlock_op_buf_size, NULL, NULL);
122 
123 	dout("%s: status %d\n", __func__, ret);
124 	__free_page(unlock_op_page);
125 	return ret;
126 }
127 EXPORT_SYMBOL(ceph_cls_unlock);
128 
129 /**
130  * ceph_cls_break_lock - release rados lock for object for specified client
131  * @oid, @oloc: object to lock
132  * @lock_name: the name of the lock
133  * @cookie: user-defined identifier for this instance of the lock
134  * @locker: current lock owner
135  */
136 int ceph_cls_break_lock(struct ceph_osd_client *osdc,
137 			struct ceph_object_id *oid,
138 			struct ceph_object_locator *oloc,
139 			char *lock_name, char *cookie,
140 			struct ceph_entity_name *locker)
141 {
142 	int break_op_buf_size;
143 	int name_len = strlen(lock_name);
144 	int cookie_len = strlen(cookie);
145 	struct page *break_op_page;
146 	void *p, *end;
147 	int ret;
148 
149 	break_op_buf_size = name_len + sizeof(__le32) +
150 			    cookie_len + sizeof(__le32) +
151 			    sizeof(u8) + sizeof(__le64) +
152 			    CEPH_ENCODING_START_BLK_LEN;
153 	if (break_op_buf_size > PAGE_SIZE)
154 		return -E2BIG;
155 
156 	break_op_page = alloc_page(GFP_NOIO);
157 	if (!break_op_page)
158 		return -ENOMEM;
159 
160 	p = page_address(break_op_page);
161 	end = p + break_op_buf_size;
162 
163 	/* encode cls_lock_break_op struct */
164 	ceph_start_encoding(&p, 1, 1,
165 			    break_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
166 	ceph_encode_string(&p, end, lock_name, name_len);
167 	ceph_encode_copy(&p, locker, sizeof(*locker));
168 	ceph_encode_string(&p, end, cookie, cookie_len);
169 
170 	dout("%s lock_name %s cookie %s locker %s%llu\n", __func__, lock_name,
171 	     cookie, ENTITY_NAME(*locker));
172 	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "break_lock",
173 			     CEPH_OSD_FLAG_WRITE, break_op_page,
174 			     break_op_buf_size, NULL, NULL);
175 
176 	dout("%s: status %d\n", __func__, ret);
177 	__free_page(break_op_page);
178 	return ret;
179 }
180 EXPORT_SYMBOL(ceph_cls_break_lock);
181 
182 void ceph_free_lockers(struct ceph_locker *lockers, u32 num_lockers)
183 {
184 	int i;
185 
186 	for (i = 0; i < num_lockers; i++)
187 		kfree(lockers[i].id.cookie);
188 	kfree(lockers);
189 }
190 EXPORT_SYMBOL(ceph_free_lockers);
191 
192 static int decode_locker(void **p, void *end, struct ceph_locker *locker)
193 {
194 	u8 struct_v;
195 	u32 len;
196 	char *s;
197 	int ret;
198 
199 	ret = ceph_start_decoding(p, end, 1, "locker_id_t", &struct_v, &len);
200 	if (ret)
201 		return ret;
202 
203 	ceph_decode_copy(p, &locker->id.name, sizeof(locker->id.name));
204 	s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
205 	if (IS_ERR(s))
206 		return PTR_ERR(s);
207 
208 	locker->id.cookie = s;
209 
210 	ret = ceph_start_decoding(p, end, 1, "locker_info_t", &struct_v, &len);
211 	if (ret)
212 		return ret;
213 
214 	*p += sizeof(struct ceph_timespec); /* skip expiration */
215 	ceph_decode_copy(p, &locker->info.addr, sizeof(locker->info.addr));
216 	ceph_decode_addr(&locker->info.addr);
217 	len = ceph_decode_32(p);
218 	*p += len; /* skip description */
219 
220 	dout("%s %s%llu cookie %s addr %s\n", __func__,
221 	     ENTITY_NAME(locker->id.name), locker->id.cookie,
222 	     ceph_pr_addr(&locker->info.addr.in_addr));
223 	return 0;
224 }
225 
226 static int decode_lockers(void **p, void *end, u8 *type, char **tag,
227 			  struct ceph_locker **lockers, u32 *num_lockers)
228 {
229 	u8 struct_v;
230 	u32 struct_len;
231 	char *s;
232 	int i;
233 	int ret;
234 
235 	ret = ceph_start_decoding(p, end, 1, "cls_lock_get_info_reply",
236 				  &struct_v, &struct_len);
237 	if (ret)
238 		return ret;
239 
240 	*num_lockers = ceph_decode_32(p);
241 	*lockers = kcalloc(*num_lockers, sizeof(**lockers), GFP_NOIO);
242 	if (!*lockers)
243 		return -ENOMEM;
244 
245 	for (i = 0; i < *num_lockers; i++) {
246 		ret = decode_locker(p, end, *lockers + i);
247 		if (ret)
248 			goto err_free_lockers;
249 	}
250 
251 	*type = ceph_decode_8(p);
252 	s = ceph_extract_encoded_string(p, end, NULL, GFP_NOIO);
253 	if (IS_ERR(s)) {
254 		ret = PTR_ERR(s);
255 		goto err_free_lockers;
256 	}
257 
258 	*tag = s;
259 	return 0;
260 
261 err_free_lockers:
262 	ceph_free_lockers(*lockers, *num_lockers);
263 	return ret;
264 }
265 
266 /*
267  * On success, the caller is responsible for:
268  *
269  *     kfree(tag);
270  *     ceph_free_lockers(lockers, num_lockers);
271  */
272 int ceph_cls_lock_info(struct ceph_osd_client *osdc,
273 		       struct ceph_object_id *oid,
274 		       struct ceph_object_locator *oloc,
275 		       char *lock_name, u8 *type, char **tag,
276 		       struct ceph_locker **lockers, u32 *num_lockers)
277 {
278 	int get_info_op_buf_size;
279 	int name_len = strlen(lock_name);
280 	struct page *get_info_op_page, *reply_page;
281 	size_t reply_len = PAGE_SIZE;
282 	void *p, *end;
283 	int ret;
284 
285 	get_info_op_buf_size = name_len + sizeof(__le32) +
286 			       CEPH_ENCODING_START_BLK_LEN;
287 	if (get_info_op_buf_size > PAGE_SIZE)
288 		return -E2BIG;
289 
290 	get_info_op_page = alloc_page(GFP_NOIO);
291 	if (!get_info_op_page)
292 		return -ENOMEM;
293 
294 	reply_page = alloc_page(GFP_NOIO);
295 	if (!reply_page) {
296 		__free_page(get_info_op_page);
297 		return -ENOMEM;
298 	}
299 
300 	p = page_address(get_info_op_page);
301 	end = p + get_info_op_buf_size;
302 
303 	/* encode cls_lock_get_info_op struct */
304 	ceph_start_encoding(&p, 1, 1,
305 			    get_info_op_buf_size - CEPH_ENCODING_START_BLK_LEN);
306 	ceph_encode_string(&p, end, lock_name, name_len);
307 
308 	dout("%s lock_name %s\n", __func__, lock_name);
309 	ret = ceph_osdc_call(osdc, oid, oloc, "lock", "get_info",
310 			     CEPH_OSD_FLAG_READ, get_info_op_page,
311 			     get_info_op_buf_size, reply_page, &reply_len);
312 
313 	dout("%s: status %d\n", __func__, ret);
314 	if (ret >= 0) {
315 		p = page_address(reply_page);
316 		end = p + reply_len;
317 
318 		ret = decode_lockers(&p, end, type, tag, lockers, num_lockers);
319 	}
320 
321 	__free_page(get_info_op_page);
322 	__free_page(reply_page);
323 	return ret;
324 }
325 EXPORT_SYMBOL(ceph_cls_lock_info);
326