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 ceph_file_info *fi = dst->fl_file->private_data; 36 struct inode *inode = file_inode(dst->fl_file); 37 atomic_inc(&ceph_inode(inode)->i_filelock_ref); 38 atomic_inc(&fi->num_locks); 39 } 40 41 static void ceph_fl_release_lock(struct file_lock *fl) 42 { 43 struct ceph_file_info *fi = fl->fl_file->private_data; 44 struct inode *inode = file_inode(fl->fl_file); 45 struct ceph_inode_info *ci = ceph_inode(inode); 46 atomic_dec(&fi->num_locks); 47 if (atomic_dec_and_test(&ci->i_filelock_ref)) { 48 /* clear error when all locks are released */ 49 spin_lock(&ci->i_ceph_lock); 50 ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; 51 spin_unlock(&ci->i_ceph_lock); 52 } 53 } 54 55 static const struct file_lock_operations ceph_fl_lock_ops = { 56 .fl_copy_lock = ceph_fl_copy_lock, 57 .fl_release_private = ceph_fl_release_lock, 58 }; 59 60 /* 61 * Implement fcntl and flock locking functions. 62 */ 63 static int ceph_lock_message(u8 lock_type, u16 operation, struct inode *inode, 64 int cmd, u8 wait, struct file_lock *fl) 65 { 66 struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(inode->i_sb); 67 struct ceph_mds_request *req; 68 int err; 69 u64 length = 0; 70 u64 owner; 71 72 if (operation == CEPH_MDS_OP_SETFILELOCK) { 73 /* 74 * increasing i_filelock_ref closes race window between 75 * handling request reply and adding file_lock struct to 76 * inode. Otherwise, auth caps may get trimmed in the 77 * window. Caller function will decrease the counter. 78 */ 79 fl->fl_ops = &ceph_fl_lock_ops; 80 fl->fl_ops->fl_copy_lock(fl, NULL); 81 } 82 83 if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK) 84 wait = 0; 85 86 req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); 87 if (IS_ERR(req)) 88 return PTR_ERR(req); 89 req->r_inode = inode; 90 ihold(inode); 91 req->r_num_caps = 1; 92 93 /* mds requires start and length rather than start and end */ 94 if (LLONG_MAX == fl->fl_end) 95 length = 0; 96 else 97 length = fl->fl_end - fl->fl_start + 1; 98 99 owner = secure_addr(fl->fl_owner); 100 101 dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, " 102 "start: %llu, length: %llu, wait: %d, type: %d\n", (int)lock_type, 103 (int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length, 104 wait, fl->fl_type); 105 106 req->r_args.filelock_change.rule = lock_type; 107 req->r_args.filelock_change.type = cmd; 108 req->r_args.filelock_change.owner = cpu_to_le64(owner); 109 req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); 110 req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); 111 req->r_args.filelock_change.length = cpu_to_le64(length); 112 req->r_args.filelock_change.wait = wait; 113 114 if (wait) 115 req->r_wait_for_completion = ceph_lock_wait_for_completion; 116 117 err = ceph_mdsc_do_request(mdsc, inode, req); 118 if (!err && operation == CEPH_MDS_OP_GETFILELOCK) { 119 fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid); 120 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) 121 fl->fl_type = F_RDLCK; 122 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) 123 fl->fl_type = F_WRLCK; 124 else 125 fl->fl_type = F_UNLCK; 126 127 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); 128 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + 129 le64_to_cpu(req->r_reply_info.filelock_reply->length); 130 if (length >= 1) 131 fl->fl_end = length -1; 132 else 133 fl->fl_end = 0; 134 135 } 136 ceph_mdsc_put_request(req); 137 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 138 "length: %llu, wait: %d, type: %d, err code %d\n", (int)lock_type, 139 (int)operation, (u64)fl->fl_pid, fl->fl_start, 140 length, wait, fl->fl_type, err); 141 return err; 142 } 143 144 static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, 145 struct ceph_mds_request *req) 146 { 147 struct ceph_mds_request *intr_req; 148 struct inode *inode = req->r_inode; 149 int err, lock_type; 150 151 BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); 152 if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) 153 lock_type = CEPH_LOCK_FCNTL_INTR; 154 else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) 155 lock_type = CEPH_LOCK_FLOCK_INTR; 156 else 157 BUG_ON(1); 158 BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); 159 160 err = wait_for_completion_interruptible(&req->r_completion); 161 if (!err) 162 return 0; 163 164 dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", 165 req->r_tid); 166 167 mutex_lock(&mdsc->mutex); 168 if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { 169 err = 0; 170 } else { 171 /* 172 * ensure we aren't running concurrently with 173 * ceph_fill_trace or ceph_readdir_prepopulate, which 174 * rely on locks (dir mutex) held by our caller. 175 */ 176 mutex_lock(&req->r_fill_mutex); 177 req->r_err = err; 178 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); 179 mutex_unlock(&req->r_fill_mutex); 180 181 if (!req->r_session) { 182 // haven't sent the request 183 err = 0; 184 } 185 } 186 mutex_unlock(&mdsc->mutex); 187 if (!err) 188 return 0; 189 190 intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, 191 USE_AUTH_MDS); 192 if (IS_ERR(intr_req)) 193 return PTR_ERR(intr_req); 194 195 intr_req->r_inode = inode; 196 ihold(inode); 197 intr_req->r_num_caps = 1; 198 199 intr_req->r_args.filelock_change = req->r_args.filelock_change; 200 intr_req->r_args.filelock_change.rule = lock_type; 201 intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; 202 203 err = ceph_mdsc_do_request(mdsc, inode, intr_req); 204 ceph_mdsc_put_request(intr_req); 205 206 if (err && err != -ERESTARTSYS) 207 return err; 208 209 wait_for_completion_killable(&req->r_safe_completion); 210 return 0; 211 } 212 213 static int try_unlock_file(struct file *file, struct file_lock *fl) 214 { 215 int err; 216 unsigned int orig_flags = fl->fl_flags; 217 fl->fl_flags |= FL_EXISTS; 218 err = locks_lock_file_wait(file, fl); 219 fl->fl_flags = orig_flags; 220 if (err == -ENOENT) { 221 if (!(orig_flags & FL_EXISTS)) 222 err = 0; 223 return err; 224 } 225 return 1; 226 } 227 228 /* 229 * Attempt to set an fcntl lock. 230 * For now, this just goes away to the server. Later it may be more awesome. 231 */ 232 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 233 { 234 struct inode *inode = file_inode(file); 235 struct ceph_inode_info *ci = ceph_inode(inode); 236 int err = 0; 237 u16 op = CEPH_MDS_OP_SETFILELOCK; 238 u8 wait = 0; 239 u8 lock_cmd; 240 241 if (!(fl->fl_flags & FL_POSIX)) 242 return -ENOLCK; 243 244 dout("ceph_lock, fl_owner: %p\n", fl->fl_owner); 245 246 /* set wait bit as appropriate, then make command as Ceph expects it*/ 247 if (IS_GETLK(cmd)) 248 op = CEPH_MDS_OP_GETFILELOCK; 249 else if (IS_SETLKW(cmd)) 250 wait = 1; 251 252 spin_lock(&ci->i_ceph_lock); 253 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 254 err = -EIO; 255 } 256 spin_unlock(&ci->i_ceph_lock); 257 if (err < 0) { 258 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) 259 posix_lock_file(file, fl, NULL); 260 return err; 261 } 262 263 if (F_RDLCK == fl->fl_type) 264 lock_cmd = CEPH_LOCK_SHARED; 265 else if (F_WRLCK == fl->fl_type) 266 lock_cmd = CEPH_LOCK_EXCL; 267 else 268 lock_cmd = CEPH_LOCK_UNLOCK; 269 270 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) { 271 err = try_unlock_file(file, fl); 272 if (err <= 0) 273 return err; 274 } 275 276 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); 277 if (!err) { 278 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK != fl->fl_type) { 279 dout("mds locked, locking locally\n"); 280 err = posix_lock_file(file, fl, NULL); 281 if (err) { 282 /* undo! This should only happen if 283 * the kernel detects local 284 * deadlock. */ 285 ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, 286 CEPH_LOCK_UNLOCK, 0, fl); 287 dout("got %d on posix_lock_file, undid lock\n", 288 err); 289 } 290 } 291 } 292 return err; 293 } 294 295 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 296 { 297 struct inode *inode = file_inode(file); 298 struct ceph_inode_info *ci = ceph_inode(inode); 299 int err = 0; 300 u8 wait = 0; 301 u8 lock_cmd; 302 303 if (!(fl->fl_flags & FL_FLOCK)) 304 return -ENOLCK; 305 /* No mandatory locks */ 306 if (fl->fl_type & LOCK_MAND) 307 return -EOPNOTSUPP; 308 309 dout("ceph_flock, fl_file: %p\n", fl->fl_file); 310 311 spin_lock(&ci->i_ceph_lock); 312 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 313 err = -EIO; 314 } 315 spin_unlock(&ci->i_ceph_lock); 316 if (err < 0) { 317 if (F_UNLCK == fl->fl_type) 318 locks_lock_file_wait(file, fl); 319 return err; 320 } 321 322 if (IS_SETLKW(cmd)) 323 wait = 1; 324 325 if (F_RDLCK == fl->fl_type) 326 lock_cmd = CEPH_LOCK_SHARED; 327 else if (F_WRLCK == fl->fl_type) 328 lock_cmd = CEPH_LOCK_EXCL; 329 else 330 lock_cmd = CEPH_LOCK_UNLOCK; 331 332 if (F_UNLCK == fl->fl_type) { 333 err = try_unlock_file(file, fl); 334 if (err <= 0) 335 return err; 336 } 337 338 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 339 inode, lock_cmd, wait, fl); 340 if (!err && F_UNLCK != fl->fl_type) { 341 err = locks_lock_file_wait(file, fl); 342 if (err) { 343 ceph_lock_message(CEPH_LOCK_FLOCK, 344 CEPH_MDS_OP_SETFILELOCK, 345 inode, CEPH_LOCK_UNLOCK, 0, fl); 346 dout("got %d on locks_lock_file_wait, undid lock\n", err); 347 } 348 } 349 return err; 350 } 351 352 /* 353 * Fills in the passed counter variables, so you can prepare pagelist metadata 354 * before calling ceph_encode_locks. 355 */ 356 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 357 { 358 struct file_lock *lock; 359 struct file_lock_context *ctx; 360 361 *fcntl_count = 0; 362 *flock_count = 0; 363 364 ctx = inode->i_flctx; 365 if (ctx) { 366 spin_lock(&ctx->flc_lock); 367 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 368 ++(*fcntl_count); 369 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 370 ++(*flock_count); 371 spin_unlock(&ctx->flc_lock); 372 } 373 dout("counted %d flock locks and %d fcntl locks\n", 374 *flock_count, *fcntl_count); 375 } 376 377 /* 378 * Given a pointer to a lock, convert it to a ceph filelock 379 */ 380 static int lock_to_ceph_filelock(struct file_lock *lock, 381 struct ceph_filelock *cephlock) 382 { 383 int err = 0; 384 cephlock->start = cpu_to_le64(lock->fl_start); 385 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 386 cephlock->client = cpu_to_le64(0); 387 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 388 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 389 390 switch (lock->fl_type) { 391 case F_RDLCK: 392 cephlock->type = CEPH_LOCK_SHARED; 393 break; 394 case F_WRLCK: 395 cephlock->type = CEPH_LOCK_EXCL; 396 break; 397 case F_UNLCK: 398 cephlock->type = CEPH_LOCK_UNLOCK; 399 break; 400 default: 401 dout("Have unknown lock type %d\n", lock->fl_type); 402 err = -EINVAL; 403 } 404 405 return err; 406 } 407 408 /* 409 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 410 * array. Must be called with inode->i_lock already held. 411 * If we encounter more of a specific lock type than expected, return -ENOSPC. 412 */ 413 int ceph_encode_locks_to_buffer(struct inode *inode, 414 struct ceph_filelock *flocks, 415 int num_fcntl_locks, int num_flock_locks) 416 { 417 struct file_lock *lock; 418 struct file_lock_context *ctx = inode->i_flctx; 419 int err = 0; 420 int seen_fcntl = 0; 421 int seen_flock = 0; 422 int l = 0; 423 424 dout("encoding %d flock and %d fcntl locks\n", num_flock_locks, 425 num_fcntl_locks); 426 427 if (!ctx) 428 return 0; 429 430 spin_lock(&ctx->flc_lock); 431 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 432 ++seen_fcntl; 433 if (seen_fcntl > num_fcntl_locks) { 434 err = -ENOSPC; 435 goto fail; 436 } 437 err = lock_to_ceph_filelock(lock, &flocks[l]); 438 if (err) 439 goto fail; 440 ++l; 441 } 442 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 443 ++seen_flock; 444 if (seen_flock > num_flock_locks) { 445 err = -ENOSPC; 446 goto fail; 447 } 448 err = lock_to_ceph_filelock(lock, &flocks[l]); 449 if (err) 450 goto fail; 451 ++l; 452 } 453 fail: 454 spin_unlock(&ctx->flc_lock); 455 return err; 456 } 457 458 /* 459 * Copy the encoded flock and fcntl locks into the pagelist. 460 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 461 * sequential flock locks. 462 * Returns zero on success. 463 */ 464 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 465 struct ceph_pagelist *pagelist, 466 int num_fcntl_locks, int num_flock_locks) 467 { 468 int err = 0; 469 __le32 nlocks; 470 471 nlocks = cpu_to_le32(num_fcntl_locks); 472 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 473 if (err) 474 goto out_fail; 475 476 if (num_fcntl_locks > 0) { 477 err = ceph_pagelist_append(pagelist, flocks, 478 num_fcntl_locks * sizeof(*flocks)); 479 if (err) 480 goto out_fail; 481 } 482 483 nlocks = cpu_to_le32(num_flock_locks); 484 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 485 if (err) 486 goto out_fail; 487 488 if (num_flock_locks > 0) { 489 err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], 490 num_flock_locks * sizeof(*flocks)); 491 } 492 out_fail: 493 return err; 494 } 495