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 /* No mandatory locks */ 244 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) 245 return -ENOLCK; 246 247 dout("ceph_lock, fl_owner: %p\n", fl->fl_owner); 248 249 /* set wait bit as appropriate, then make command as Ceph expects it*/ 250 if (IS_GETLK(cmd)) 251 op = CEPH_MDS_OP_GETFILELOCK; 252 else if (IS_SETLKW(cmd)) 253 wait = 1; 254 255 spin_lock(&ci->i_ceph_lock); 256 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 257 err = -EIO; 258 } 259 spin_unlock(&ci->i_ceph_lock); 260 if (err < 0) { 261 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) 262 posix_lock_file(file, fl, NULL); 263 return err; 264 } 265 266 if (F_RDLCK == fl->fl_type) 267 lock_cmd = CEPH_LOCK_SHARED; 268 else if (F_WRLCK == fl->fl_type) 269 lock_cmd = CEPH_LOCK_EXCL; 270 else 271 lock_cmd = CEPH_LOCK_UNLOCK; 272 273 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) { 274 err = try_unlock_file(file, fl); 275 if (err <= 0) 276 return err; 277 } 278 279 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); 280 if (!err) { 281 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK != fl->fl_type) { 282 dout("mds locked, locking locally\n"); 283 err = posix_lock_file(file, fl, NULL); 284 if (err) { 285 /* undo! This should only happen if 286 * the kernel detects local 287 * deadlock. */ 288 ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, 289 CEPH_LOCK_UNLOCK, 0, fl); 290 dout("got %d on posix_lock_file, undid lock\n", 291 err); 292 } 293 } 294 } 295 return err; 296 } 297 298 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 299 { 300 struct inode *inode = file_inode(file); 301 struct ceph_inode_info *ci = ceph_inode(inode); 302 int err = 0; 303 u8 wait = 0; 304 u8 lock_cmd; 305 306 if (!(fl->fl_flags & FL_FLOCK)) 307 return -ENOLCK; 308 /* No mandatory locks */ 309 if (fl->fl_type & LOCK_MAND) 310 return -EOPNOTSUPP; 311 312 dout("ceph_flock, fl_file: %p\n", fl->fl_file); 313 314 spin_lock(&ci->i_ceph_lock); 315 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 316 err = -EIO; 317 } 318 spin_unlock(&ci->i_ceph_lock); 319 if (err < 0) { 320 if (F_UNLCK == fl->fl_type) 321 locks_lock_file_wait(file, fl); 322 return err; 323 } 324 325 if (IS_SETLKW(cmd)) 326 wait = 1; 327 328 if (F_RDLCK == fl->fl_type) 329 lock_cmd = CEPH_LOCK_SHARED; 330 else if (F_WRLCK == fl->fl_type) 331 lock_cmd = CEPH_LOCK_EXCL; 332 else 333 lock_cmd = CEPH_LOCK_UNLOCK; 334 335 if (F_UNLCK == fl->fl_type) { 336 err = try_unlock_file(file, fl); 337 if (err <= 0) 338 return err; 339 } 340 341 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 342 inode, lock_cmd, wait, fl); 343 if (!err && F_UNLCK != fl->fl_type) { 344 err = locks_lock_file_wait(file, fl); 345 if (err) { 346 ceph_lock_message(CEPH_LOCK_FLOCK, 347 CEPH_MDS_OP_SETFILELOCK, 348 inode, CEPH_LOCK_UNLOCK, 0, fl); 349 dout("got %d on locks_lock_file_wait, undid lock\n", err); 350 } 351 } 352 return err; 353 } 354 355 /* 356 * Fills in the passed counter variables, so you can prepare pagelist metadata 357 * before calling ceph_encode_locks. 358 */ 359 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 360 { 361 struct file_lock *lock; 362 struct file_lock_context *ctx; 363 364 *fcntl_count = 0; 365 *flock_count = 0; 366 367 ctx = inode->i_flctx; 368 if (ctx) { 369 spin_lock(&ctx->flc_lock); 370 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 371 ++(*fcntl_count); 372 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 373 ++(*flock_count); 374 spin_unlock(&ctx->flc_lock); 375 } 376 dout("counted %d flock locks and %d fcntl locks\n", 377 *flock_count, *fcntl_count); 378 } 379 380 /* 381 * Given a pointer to a lock, convert it to a ceph filelock 382 */ 383 static int lock_to_ceph_filelock(struct file_lock *lock, 384 struct ceph_filelock *cephlock) 385 { 386 int err = 0; 387 cephlock->start = cpu_to_le64(lock->fl_start); 388 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 389 cephlock->client = cpu_to_le64(0); 390 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 391 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 392 393 switch (lock->fl_type) { 394 case F_RDLCK: 395 cephlock->type = CEPH_LOCK_SHARED; 396 break; 397 case F_WRLCK: 398 cephlock->type = CEPH_LOCK_EXCL; 399 break; 400 case F_UNLCK: 401 cephlock->type = CEPH_LOCK_UNLOCK; 402 break; 403 default: 404 dout("Have unknown lock type %d\n", lock->fl_type); 405 err = -EINVAL; 406 } 407 408 return err; 409 } 410 411 /** 412 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 413 * array. Must be called with inode->i_lock already held. 414 * If we encounter more of a specific lock type than expected, return -ENOSPC. 415 */ 416 int ceph_encode_locks_to_buffer(struct inode *inode, 417 struct ceph_filelock *flocks, 418 int num_fcntl_locks, int num_flock_locks) 419 { 420 struct file_lock *lock; 421 struct file_lock_context *ctx = inode->i_flctx; 422 int err = 0; 423 int seen_fcntl = 0; 424 int seen_flock = 0; 425 int l = 0; 426 427 dout("encoding %d flock and %d fcntl locks\n", num_flock_locks, 428 num_fcntl_locks); 429 430 if (!ctx) 431 return 0; 432 433 spin_lock(&ctx->flc_lock); 434 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 435 ++seen_fcntl; 436 if (seen_fcntl > num_fcntl_locks) { 437 err = -ENOSPC; 438 goto fail; 439 } 440 err = lock_to_ceph_filelock(lock, &flocks[l]); 441 if (err) 442 goto fail; 443 ++l; 444 } 445 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 446 ++seen_flock; 447 if (seen_flock > num_flock_locks) { 448 err = -ENOSPC; 449 goto fail; 450 } 451 err = lock_to_ceph_filelock(lock, &flocks[l]); 452 if (err) 453 goto fail; 454 ++l; 455 } 456 fail: 457 spin_unlock(&ctx->flc_lock); 458 return err; 459 } 460 461 /** 462 * Copy the encoded flock and fcntl locks into the pagelist. 463 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 464 * sequential flock locks. 465 * Returns zero on success. 466 */ 467 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 468 struct ceph_pagelist *pagelist, 469 int num_fcntl_locks, int num_flock_locks) 470 { 471 int err = 0; 472 __le32 nlocks; 473 474 nlocks = cpu_to_le32(num_fcntl_locks); 475 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 476 if (err) 477 goto out_fail; 478 479 if (num_fcntl_locks > 0) { 480 err = ceph_pagelist_append(pagelist, flocks, 481 num_fcntl_locks * sizeof(*flocks)); 482 if (err) 483 goto out_fail; 484 } 485 486 nlocks = cpu_to_le32(num_flock_locks); 487 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 488 if (err) 489 goto out_fail; 490 491 if (num_flock_locks > 0) { 492 err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], 493 num_flock_locks * sizeof(*flocks)); 494 } 495 out_fail: 496 return err; 497 } 498