1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * (C) 2001 Clemson University and The University of Chicago |
4 | * (C) 2011 Omnibond Systems |
5 | * |
6 | * Changes by Acxiom Corporation to implement generic service_operation() |
7 | * function, Copyright Acxiom Corporation, 2005. |
8 | * |
9 | * See COPYING in top-level directory. |
10 | */ |
11 | |
12 | /* |
13 | * In-kernel waitqueue operations. |
14 | */ |
15 | |
16 | #include "protocol.h" |
17 | #include "orangefs-kernel.h" |
18 | #include "orangefs-bufmap.h" |
19 | |
20 | static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op, |
21 | long timeout, |
22 | int flags) |
23 | __acquires(op->lock); |
24 | static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op) |
25 | __releases(op->lock); |
26 | |
27 | /* |
28 | * What we do in this function is to walk the list of operations that are |
29 | * present in the request queue and mark them as purged. |
30 | * NOTE: This is called from the device close after client-core has |
31 | * guaranteed that no new operations could appear on the list since the |
32 | * client-core is anyway going to exit. |
33 | */ |
34 | void purge_waiting_ops(void) |
35 | { |
36 | struct orangefs_kernel_op_s *op, *tmp; |
37 | |
38 | spin_lock(lock: &orangefs_request_list_lock); |
39 | list_for_each_entry_safe(op, tmp, &orangefs_request_list, list) { |
40 | gossip_debug(GOSSIP_WAIT_DEBUG, |
41 | "pvfs2-client-core: purging op tag %llu %s\n" , |
42 | llu(op->tag), |
43 | get_opname_string(op)); |
44 | set_op_state_purged(op); |
45 | gossip_debug(GOSSIP_DEV_DEBUG, |
46 | "%s: op:%s: op_state:%d: process:%s:\n" , |
47 | __func__, |
48 | get_opname_string(op), |
49 | op->op_state, |
50 | current->comm); |
51 | } |
52 | spin_unlock(lock: &orangefs_request_list_lock); |
53 | } |
54 | |
55 | /* |
56 | * submits a ORANGEFS operation and waits for it to complete |
57 | * |
58 | * Note op->downcall.status will contain the status of the operation (in |
59 | * errno format), whether provided by pvfs2-client or a result of failure to |
60 | * service the operation. If the caller wishes to distinguish, then |
61 | * op->state can be checked to see if it was serviced or not. |
62 | * |
63 | * Returns contents of op->downcall.status for convenience |
64 | */ |
65 | int service_operation(struct orangefs_kernel_op_s *op, |
66 | const char *op_name, |
67 | int flags) |
68 | { |
69 | long timeout = MAX_SCHEDULE_TIMEOUT; |
70 | int ret = 0; |
71 | |
72 | DEFINE_WAIT(wait_entry); |
73 | |
74 | op->upcall.tgid = current->tgid; |
75 | op->upcall.pid = current->pid; |
76 | |
77 | retry_servicing: |
78 | op->downcall.status = 0; |
79 | gossip_debug(GOSSIP_WAIT_DEBUG, |
80 | "%s: %s op:%p: process:%s: pid:%d:\n" , |
81 | __func__, |
82 | op_name, |
83 | op, |
84 | current->comm, |
85 | current->pid); |
86 | |
87 | /* |
88 | * If ORANGEFS_OP_NO_MUTEX was set in flags, we need to avoid |
89 | * acquiring the request_mutex because we're servicing a |
90 | * high priority remount operation and the request_mutex is |
91 | * already taken. |
92 | */ |
93 | if (!(flags & ORANGEFS_OP_NO_MUTEX)) { |
94 | if (flags & ORANGEFS_OP_INTERRUPTIBLE) |
95 | ret = mutex_lock_interruptible(&orangefs_request_mutex); |
96 | else |
97 | ret = mutex_lock_killable(&orangefs_request_mutex); |
98 | /* |
99 | * check to see if we were interrupted while waiting for |
100 | * mutex |
101 | */ |
102 | if (ret < 0) { |
103 | op->downcall.status = ret; |
104 | gossip_debug(GOSSIP_WAIT_DEBUG, |
105 | "%s: service_operation interrupted.\n" , |
106 | __func__); |
107 | return ret; |
108 | } |
109 | } |
110 | |
111 | /* queue up the operation */ |
112 | spin_lock(lock: &orangefs_request_list_lock); |
113 | spin_lock(lock: &op->lock); |
114 | set_op_state_waiting(op); |
115 | gossip_debug(GOSSIP_DEV_DEBUG, |
116 | "%s: op:%s: op_state:%d: process:%s:\n" , |
117 | __func__, |
118 | get_opname_string(op), |
119 | op->op_state, |
120 | current->comm); |
121 | /* add high priority remount op to the front of the line. */ |
122 | if (flags & ORANGEFS_OP_PRIORITY) |
123 | list_add(new: &op->list, head: &orangefs_request_list); |
124 | else |
125 | list_add_tail(new: &op->list, head: &orangefs_request_list); |
126 | spin_unlock(lock: &op->lock); |
127 | wake_up_interruptible(&orangefs_request_list_waitq); |
128 | if (!__is_daemon_in_service()) { |
129 | gossip_debug(GOSSIP_WAIT_DEBUG, |
130 | "%s:client core is NOT in service.\n" , |
131 | __func__); |
132 | /* |
133 | * Don't wait for the userspace component to return if |
134 | * the filesystem is being umounted anyway. |
135 | */ |
136 | if (op->upcall.type == ORANGEFS_VFS_OP_FS_UMOUNT) |
137 | timeout = 0; |
138 | else |
139 | timeout = op_timeout_secs * HZ; |
140 | } |
141 | spin_unlock(lock: &orangefs_request_list_lock); |
142 | |
143 | if (!(flags & ORANGEFS_OP_NO_MUTEX)) |
144 | mutex_unlock(lock: &orangefs_request_mutex); |
145 | |
146 | ret = wait_for_matching_downcall(op, timeout, flags); |
147 | gossip_debug(GOSSIP_WAIT_DEBUG, |
148 | "%s: wait_for_matching_downcall returned %d for %p\n" , |
149 | __func__, |
150 | ret, |
151 | op); |
152 | |
153 | /* got matching downcall; make sure status is in errno format */ |
154 | if (!ret) { |
155 | spin_unlock(lock: &op->lock); |
156 | op->downcall.status = |
157 | orangefs_normalize_to_errno(error_code: op->downcall.status); |
158 | ret = op->downcall.status; |
159 | goto out; |
160 | } |
161 | |
162 | /* failed to get matching downcall */ |
163 | if (ret == -ETIMEDOUT) { |
164 | gossip_err("%s: %s -- wait timed out; aborting attempt.\n" , |
165 | __func__, |
166 | op_name); |
167 | } |
168 | |
169 | /* |
170 | * remove a waiting op from the request list or |
171 | * remove an in-progress op from the in-progress list. |
172 | */ |
173 | orangefs_clean_up_interrupted_operation(op); |
174 | |
175 | op->downcall.status = ret; |
176 | /* retry if operation has not been serviced and if requested */ |
177 | if (ret == -EAGAIN) { |
178 | op->attempts++; |
179 | timeout = op_timeout_secs * HZ; |
180 | gossip_debug(GOSSIP_WAIT_DEBUG, |
181 | "orangefs: tag %llu (%s)" |
182 | " -- operation to be retried (%d attempt)\n" , |
183 | llu(op->tag), |
184 | op_name, |
185 | op->attempts); |
186 | |
187 | /* |
188 | * io ops (ops that use the shared memory buffer) have |
189 | * to be returned to their caller for a retry. Other ops |
190 | * can just be recycled here. |
191 | */ |
192 | if (!op->uses_shared_memory) |
193 | goto retry_servicing; |
194 | } |
195 | |
196 | out: |
197 | gossip_debug(GOSSIP_WAIT_DEBUG, |
198 | "%s: %s returning: %d for %p.\n" , |
199 | __func__, |
200 | op_name, |
201 | ret, |
202 | op); |
203 | return ret; |
204 | } |
205 | |
206 | /* This can get called on an I/O op if it had a bad service_operation. */ |
207 | bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op) |
208 | { |
209 | u64 tag = op->tag; |
210 | if (!op_state_in_progress(op)) |
211 | return false; |
212 | |
213 | op->slot_to_free = op->upcall.req.io.buf_index; |
214 | memset(&op->upcall, 0, sizeof(op->upcall)); |
215 | memset(&op->downcall, 0, sizeof(op->downcall)); |
216 | op->upcall.type = ORANGEFS_VFS_OP_CANCEL; |
217 | op->upcall.req.cancel.op_tag = tag; |
218 | op->downcall.type = ORANGEFS_VFS_OP_INVALID; |
219 | op->downcall.status = -1; |
220 | orangefs_new_tag(op); |
221 | |
222 | spin_lock(lock: &orangefs_request_list_lock); |
223 | /* orangefs_request_list_lock is enough of a barrier here */ |
224 | if (!__is_daemon_in_service()) { |
225 | spin_unlock(lock: &orangefs_request_list_lock); |
226 | return false; |
227 | } |
228 | spin_lock(lock: &op->lock); |
229 | set_op_state_waiting(op); |
230 | gossip_debug(GOSSIP_DEV_DEBUG, |
231 | "%s: op:%s: op_state:%d: process:%s:\n" , |
232 | __func__, |
233 | get_opname_string(op), |
234 | op->op_state, |
235 | current->comm); |
236 | list_add(new: &op->list, head: &orangefs_request_list); |
237 | spin_unlock(lock: &op->lock); |
238 | spin_unlock(lock: &orangefs_request_list_lock); |
239 | |
240 | gossip_debug(GOSSIP_WAIT_DEBUG, |
241 | "Attempting ORANGEFS operation cancellation of tag %llu\n" , |
242 | llu(tag)); |
243 | return true; |
244 | } |
245 | |
246 | /* |
247 | * Change an op to the "given up" state and remove it from its list. |
248 | */ |
249 | static void |
250 | orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op) |
251 | __releases(op->lock) |
252 | { |
253 | /* |
254 | * handle interrupted cases depending on what state we were in when |
255 | * the interruption is detected. |
256 | * |
257 | * Called with op->lock held. |
258 | */ |
259 | |
260 | /* |
261 | * List manipulation code elsewhere will ignore ops that |
262 | * have been given up upon. |
263 | */ |
264 | op->op_state |= OP_VFS_STATE_GIVEN_UP; |
265 | |
266 | if (list_empty(head: &op->list)) { |
267 | /* caught copying to/from daemon */ |
268 | BUG_ON(op_state_serviced(op)); |
269 | spin_unlock(lock: &op->lock); |
270 | wait_for_completion(&op->waitq); |
271 | } else if (op_state_waiting(op)) { |
272 | /* |
273 | * upcall hasn't been read; remove op from upcall request |
274 | * list. |
275 | */ |
276 | spin_unlock(lock: &op->lock); |
277 | spin_lock(lock: &orangefs_request_list_lock); |
278 | list_del_init(entry: &op->list); |
279 | spin_unlock(lock: &orangefs_request_list_lock); |
280 | gossip_debug(GOSSIP_WAIT_DEBUG, |
281 | "Interrupted: Removed op %p from request_list\n" , |
282 | op); |
283 | } else if (op_state_in_progress(op)) { |
284 | /* op must be removed from the in progress htable */ |
285 | spin_unlock(lock: &op->lock); |
286 | spin_lock(lock: &orangefs_htable_ops_in_progress_lock); |
287 | list_del_init(entry: &op->list); |
288 | spin_unlock(lock: &orangefs_htable_ops_in_progress_lock); |
289 | gossip_debug(GOSSIP_WAIT_DEBUG, |
290 | "Interrupted: Removed op %p" |
291 | " from htable_ops_in_progress\n" , |
292 | op); |
293 | } else { |
294 | spin_unlock(lock: &op->lock); |
295 | gossip_err("interrupted operation is in a weird state 0x%x\n" , |
296 | op->op_state); |
297 | } |
298 | reinit_completion(x: &op->waitq); |
299 | } |
300 | |
301 | /* |
302 | * Sleeps on waitqueue waiting for matching downcall. |
303 | * If client-core finishes servicing, then we are good to go. |
304 | * else if client-core exits, we get woken up here, and retry with a timeout |
305 | * |
306 | * When this call returns to the caller, the specified op will no |
307 | * longer be in either the in_progress hash table or on the request list. |
308 | * |
309 | * Returns 0 on success and -errno on failure |
310 | * Errors are: |
311 | * EAGAIN in case we want the caller to requeue and try again.. |
312 | * EINTR/EIO/ETIMEDOUT indicating we are done trying to service this |
313 | * operation since client-core seems to be exiting too often |
314 | * or if we were interrupted. |
315 | * |
316 | * Returns with op->lock taken. |
317 | */ |
318 | static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op, |
319 | long timeout, |
320 | int flags) |
321 | __acquires(op->lock) |
322 | { |
323 | long n; |
324 | int writeback = flags & ORANGEFS_OP_WRITEBACK, |
325 | interruptible = flags & ORANGEFS_OP_INTERRUPTIBLE; |
326 | |
327 | /* |
328 | * There's a "schedule_timeout" inside of these wait |
329 | * primitives, during which the op is out of the hands of the |
330 | * user process that needs something done and is being |
331 | * manipulated by the client-core process. |
332 | */ |
333 | if (writeback) |
334 | n = wait_for_completion_io_timeout(x: &op->waitq, timeout); |
335 | else if (!writeback && interruptible) |
336 | n = wait_for_completion_interruptible_timeout(x: &op->waitq, |
337 | timeout); |
338 | else /* !writeback && !interruptible but compiler complains */ |
339 | n = wait_for_completion_killable_timeout(x: &op->waitq, timeout); |
340 | |
341 | spin_lock(lock: &op->lock); |
342 | |
343 | if (op_state_serviced(op)) |
344 | return 0; |
345 | |
346 | if (unlikely(n < 0)) { |
347 | gossip_debug(GOSSIP_WAIT_DEBUG, |
348 | "%s: operation interrupted, tag %llu, %p\n" , |
349 | __func__, |
350 | llu(op->tag), |
351 | op); |
352 | return -EINTR; |
353 | } |
354 | if (op_state_purged(op)) { |
355 | gossip_debug(GOSSIP_WAIT_DEBUG, |
356 | "%s: operation purged, tag %llu, %p, %d\n" , |
357 | __func__, |
358 | llu(op->tag), |
359 | op, |
360 | op->attempts); |
361 | return (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ? |
362 | -EAGAIN : |
363 | -EIO; |
364 | } |
365 | /* must have timed out, then... */ |
366 | gossip_debug(GOSSIP_WAIT_DEBUG, |
367 | "%s: operation timed out, tag %llu, %p, %d)\n" , |
368 | __func__, |
369 | llu(op->tag), |
370 | op, |
371 | op->attempts); |
372 | return -ETIMEDOUT; |
373 | } |
374 | |