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