1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/ceph/ceph_debug.h> 3 4 #include <linux/file.h> 5 #include <linux/namei.h> 6 #include <linux/random.h> 7 8 #include "super.h" 9 #include "mds_client.h" 10 #include <linux/ceph/pagelist.h> 11 12 static u64 lock_secret; 13 static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, 14 struct ceph_mds_request *req); 15 16 static inline u64 secure_addr(void *addr) 17 { 18 u64 v = lock_secret ^ (u64)(unsigned long)addr; 19 /* 20 * Set the most significant bit, so that MDS knows the 'owner' 21 * is sufficient to identify the owner of lock. (old code uses 22 * both 'owner' and 'pid') 23 */ 24 v |= (1ULL << 63); 25 return v; 26 } 27 28 void __init ceph_flock_init(void) 29 { 30 get_random_bytes(&lock_secret, sizeof(lock_secret)); 31 } 32 33 static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) 34 { 35 struct inode *inode = file_inode(src->fl_file); 36 atomic_inc(&ceph_inode(inode)->i_filelock_ref); 37 } 38 39 static void ceph_fl_release_lock(struct file_lock *fl) 40 { 41 struct inode *inode = file_inode(fl->fl_file); 42 struct ceph_inode_info *ci = ceph_inode(inode); 43 if (atomic_dec_and_test(&ci->i_filelock_ref)) { 44 /* clear error when all locks are released */ 45 spin_lock(&ci->i_ceph_lock); 46 ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; 47 spin_unlock(&ci->i_ceph_lock); 48 } 49 } 50 51 static const struct file_lock_operations ceph_fl_lock_ops = { 52 .fl_copy_lock = ceph_fl_copy_lock, 53 .fl_release_private = ceph_fl_release_lock, 54 }; 55 56 /** 57 * Implement fcntl and flock locking functions. 58 */ 59 static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, 60 int cmd, u8 wait, struct file_lock *fl) 61 { 62 struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc; 63 struct ceph_mds_request *req; 64 int err; 65 u64 length = 0; 66 u64 owner; 67 68 if (operation == CEPH_MDS_OP_SETFILELOCK) { 69 /* 70 * increasing i_filelock_ref closes race window between 71 * handling request reply and adding file_lock struct to 72 * inode. Otherwise, auth caps may get trimmed in the 73 * window. Caller function will decrease the counter. 74 */ 75 fl->fl_ops = &ceph_fl_lock_ops; 76 atomic_inc(&ceph_inode(inode)->i_filelock_ref); 77 } 78 79 if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK) 80 wait = 0; 81 82 req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); 83 if (IS_ERR(req)) 84 return PTR_ERR(req); 85 req->r_inode = inode; 86 ihold(inode); 87 req->r_num_caps = 1; 88 89 /* mds requires start and length rather than start and end */ 90 if (LLONG_MAX == fl->fl_end) 91 length = 0; 92 else 93 length = fl->fl_end - fl->fl_start + 1; 94 95 owner = secure_addr(fl->fl_owner); 96 97 dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, " 98 "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type, 99 (int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length, 100 wait, fl->fl_type); 101 102 req->r_args.filelock_change.rule = lock_type; 103 req->r_args.filelock_change.type = cmd; 104 req->r_args.filelock_change.owner = cpu_to_le64(owner); 105 req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); 106 req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); 107 req->r_args.filelock_change.length = cpu_to_le64(length); 108 req->r_args.filelock_change.wait = wait; 109 110 if (wait) 111 req->r_wait_for_completion = ceph_lock_wait_for_completion; 112 113 err = ceph_mdsc_do_request(mdsc, inode, req); 114 115 if (operation == CEPH_MDS_OP_GETFILELOCK) { 116 fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid); 117 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) 118 fl->fl_type = F_RDLCK; 119 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) 120 fl->fl_type = F_WRLCK; 121 else 122 fl->fl_type = F_UNLCK; 123 124 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); 125 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + 126 le64_to_cpu(req->r_reply_info.filelock_reply->length); 127 if (length >= 1) 128 fl->fl_end = length -1; 129 else 130 fl->fl_end = 0; 131 132 } 133 ceph_mdsc_put_request(req); 134 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 135 "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type, 136 (int)operation, (u64)fl->fl_pid, fl->fl_start, 137 length, wait, fl->fl_type, err); 138 return err; 139 } 140 141 static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, 142 struct ceph_mds_request *req) 143 { 144 struct ceph_mds_request *intr_req; 145 struct inode *inode = req->r_inode; 146 int err, lock_type; 147 148 BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); 149 if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) 150 lock_type = CEPH_LOCK_FCNTL_INTR; 151 else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) 152 lock_type = CEPH_LOCK_FLOCK_INTR; 153 else 154 BUG_ON(1); 155 BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); 156 157 err = wait_for_completion_interruptible(&req->r_completion); 158 if (!err) 159 return 0; 160 161 dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", 162 req->r_tid); 163 164 mutex_lock(&mdsc->mutex); 165 if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { 166 err = 0; 167 } else { 168 /* 169 * ensure we aren't running concurrently with 170 * ceph_fill_trace or ceph_readdir_prepopulate, which 171 * rely on locks (dir mutex) held by our caller. 172 */ 173 mutex_lock(&req->r_fill_mutex); 174 req->r_err = err; 175 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); 176 mutex_unlock(&req->r_fill_mutex); 177 178 if (!req->r_session) { 179 // haven't sent the request 180 err = 0; 181 } 182 } 183 mutex_unlock(&mdsc->mutex); 184 if (!err) 185 return 0; 186 187 intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, 188 USE_AUTH_MDS); 189 if (IS_ERR(intr_req)) 190 return PTR_ERR(intr_req); 191 192 intr_req->r_inode = inode; 193 ihold(inode); 194 intr_req->r_num_caps = 1; 195 196 intr_req->r_args.filelock_change = req->r_args.filelock_change; 197 intr_req->r_args.filelock_change.rule = lock_type; 198 intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; 199 200 err = ceph_mdsc_do_request(mdsc, inode, intr_req); 201 ceph_mdsc_put_request(intr_req); 202 203 if (err && err != -ERESTARTSYS) 204 return err; 205 206 wait_for_completion_killable(&req->r_safe_completion); 207 return 0; 208 } 209 210 /** 211 * Attempt to set an fcntl lock. 212 * For now, this just goes away to the server. Later it may be more awesome. 213 */ 214 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 215 { 216 struct inode *inode = file_inode(file); 217 struct ceph_inode_info *ci = ceph_inode(inode); 218 int err = 0; 219 u16 op = CEPH_MDS_OP_SETFILELOCK; 220 u8 wait = 0; 221 u8 lock_cmd; 222 223 if (!(fl->fl_flags & FL_POSIX)) 224 return -ENOLCK; 225 /* No mandatory locks */ 226 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) 227 return -ENOLCK; 228 229 dout("ceph_lock, fl_owner: %p", fl->fl_owner); 230 231 /* set wait bit as appropriate, then make command as Ceph expects it*/ 232 if (IS_GETLK(cmd)) 233 op = CEPH_MDS_OP_GETFILELOCK; 234 else if (IS_SETLKW(cmd)) 235 wait = 1; 236 237 spin_lock(&ci->i_ceph_lock); 238 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 239 err = -EIO; 240 } else if (op == CEPH_MDS_OP_SETFILELOCK) { 241 /* 242 * increasing i_filelock_ref closes race window between 243 * handling request reply and adding file_lock struct to 244 * inode. Otherwise, i_auth_cap may get trimmed in the 245 * window. Caller function will decrease the counter. 246 */ 247 fl->fl_ops = &ceph_fl_lock_ops; 248 atomic_inc(&ci->i_filelock_ref); 249 } 250 spin_unlock(&ci->i_ceph_lock); 251 if (err < 0) { 252 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) 253 posix_lock_file(file, fl, NULL); 254 return err; 255 } 256 257 if (F_RDLCK == fl->fl_type) 258 lock_cmd = CEPH_LOCK_SHARED; 259 else if (F_WRLCK == fl->fl_type) 260 lock_cmd = CEPH_LOCK_EXCL; 261 else 262 lock_cmd = CEPH_LOCK_UNLOCK; 263 264 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); 265 if (!err) { 266 if (op == CEPH_MDS_OP_SETFILELOCK) { 267 dout("mds locked, locking locally"); 268 err = posix_lock_file(file, fl, NULL); 269 if (err) { 270 /* undo! This should only happen if 271 * the kernel detects local 272 * deadlock. */ 273 ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, 274 CEPH_LOCK_UNLOCK, 0, fl); 275 dout("got %d on posix_lock_file, undid lock", 276 err); 277 } 278 } 279 } 280 return err; 281 } 282 283 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 284 { 285 struct inode *inode = file_inode(file); 286 struct ceph_inode_info *ci = ceph_inode(inode); 287 int err = 0; 288 u8 wait = 0; 289 u8 lock_cmd; 290 291 if (!(fl->fl_flags & FL_FLOCK)) 292 return -ENOLCK; 293 /* No mandatory locks */ 294 if (fl->fl_type & LOCK_MAND) 295 return -EOPNOTSUPP; 296 297 dout("ceph_flock, fl_file: %p", fl->fl_file); 298 299 spin_lock(&ci->i_ceph_lock); 300 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 301 err = -EIO; 302 } else { 303 /* see comment in ceph_lock */ 304 fl->fl_ops = &ceph_fl_lock_ops; 305 atomic_inc(&ci->i_filelock_ref); 306 } 307 spin_unlock(&ci->i_ceph_lock); 308 if (err < 0) { 309 if (F_UNLCK == fl->fl_type) 310 locks_lock_file_wait(file, fl); 311 return err; 312 } 313 314 if (IS_SETLKW(cmd)) 315 wait = 1; 316 317 if (F_RDLCK == fl->fl_type) 318 lock_cmd = CEPH_LOCK_SHARED; 319 else if (F_WRLCK == fl->fl_type) 320 lock_cmd = CEPH_LOCK_EXCL; 321 else 322 lock_cmd = CEPH_LOCK_UNLOCK; 323 324 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 325 inode, lock_cmd, wait, fl); 326 if (!err) { 327 err = locks_lock_file_wait(file, fl); 328 if (err) { 329 ceph_lock_message(CEPH_LOCK_FLOCK, 330 CEPH_MDS_OP_SETFILELOCK, 331 inode, CEPH_LOCK_UNLOCK, 0, fl); 332 dout("got %d on locks_lock_file_wait, undid lock", err); 333 } 334 } 335 return err; 336 } 337 338 /* 339 * Fills in the passed counter variables, so you can prepare pagelist metadata 340 * before calling ceph_encode_locks. 341 */ 342 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 343 { 344 struct file_lock *lock; 345 struct file_lock_context *ctx; 346 347 *fcntl_count = 0; 348 *flock_count = 0; 349 350 ctx = inode->i_flctx; 351 if (ctx) { 352 spin_lock(&ctx->flc_lock); 353 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 354 ++(*fcntl_count); 355 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 356 ++(*flock_count); 357 spin_unlock(&ctx->flc_lock); 358 } 359 dout("counted %d flock locks and %d fcntl locks", 360 *flock_count, *fcntl_count); 361 } 362 363 /* 364 * Given a pointer to a lock, convert it to a ceph filelock 365 */ 366 static int lock_to_ceph_filelock(struct file_lock *lock, 367 struct ceph_filelock *cephlock) 368 { 369 int err = 0; 370 cephlock->start = cpu_to_le64(lock->fl_start); 371 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 372 cephlock->client = cpu_to_le64(0); 373 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 374 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 375 376 switch (lock->fl_type) { 377 case F_RDLCK: 378 cephlock->type = CEPH_LOCK_SHARED; 379 break; 380 case F_WRLCK: 381 cephlock->type = CEPH_LOCK_EXCL; 382 break; 383 case F_UNLCK: 384 cephlock->type = CEPH_LOCK_UNLOCK; 385 break; 386 default: 387 dout("Have unknown lock type %d", lock->fl_type); 388 err = -EINVAL; 389 } 390 391 return err; 392 } 393 394 /** 395 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 396 * array. Must be called with inode->i_lock already held. 397 * If we encounter more of a specific lock type than expected, return -ENOSPC. 398 */ 399 int ceph_encode_locks_to_buffer(struct inode *inode, 400 struct ceph_filelock *flocks, 401 int num_fcntl_locks, int num_flock_locks) 402 { 403 struct file_lock *lock; 404 struct file_lock_context *ctx = inode->i_flctx; 405 int err = 0; 406 int seen_fcntl = 0; 407 int seen_flock = 0; 408 int l = 0; 409 410 dout("encoding %d flock and %d fcntl locks", num_flock_locks, 411 num_fcntl_locks); 412 413 if (!ctx) 414 return 0; 415 416 spin_lock(&ctx->flc_lock); 417 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 418 ++seen_fcntl; 419 if (seen_fcntl > num_fcntl_locks) { 420 err = -ENOSPC; 421 goto fail; 422 } 423 err = lock_to_ceph_filelock(lock, &flocks[l]); 424 if (err) 425 goto fail; 426 ++l; 427 } 428 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 429 ++seen_flock; 430 if (seen_flock > num_flock_locks) { 431 err = -ENOSPC; 432 goto fail; 433 } 434 err = lock_to_ceph_filelock(lock, &flocks[l]); 435 if (err) 436 goto fail; 437 ++l; 438 } 439 fail: 440 spin_unlock(&ctx->flc_lock); 441 return err; 442 } 443 444 /** 445 * Copy the encoded flock and fcntl locks into the pagelist. 446 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 447 * sequential flock locks. 448 * Returns zero on success. 449 */ 450 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 451 struct ceph_pagelist *pagelist, 452 int num_fcntl_locks, int num_flock_locks) 453 { 454 int err = 0; 455 __le32 nlocks; 456 457 nlocks = cpu_to_le32(num_fcntl_locks); 458 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 459 if (err) 460 goto out_fail; 461 462 if (num_fcntl_locks > 0) { 463 err = ceph_pagelist_append(pagelist, flocks, 464 num_fcntl_locks * sizeof(*flocks)); 465 if (err) 466 goto out_fail; 467 } 468 469 nlocks = cpu_to_le32(num_flock_locks); 470 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 471 if (err) 472 goto out_fail; 473 474 if (num_flock_locks > 0) { 475 err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], 476 num_flock_locks * sizeof(*flocks)); 477 } 478 out_fail: 479 return err; 480 } 481