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\n", (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 if (!err && operation == CEPH_MDS_OP_GETFILELOCK) { 115 fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid); 116 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) 117 fl->fl_type = F_RDLCK; 118 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) 119 fl->fl_type = F_WRLCK; 120 else 121 fl->fl_type = F_UNLCK; 122 123 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); 124 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + 125 le64_to_cpu(req->r_reply_info.filelock_reply->length); 126 if (length >= 1) 127 fl->fl_end = length -1; 128 else 129 fl->fl_end = 0; 130 131 } 132 ceph_mdsc_put_request(req); 133 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 134 "length: %llu, wait: %d, type: %d, err code %d\n", (int)lock_type, 135 (int)operation, (u64)fl->fl_pid, fl->fl_start, 136 length, wait, fl->fl_type, err); 137 return err; 138 } 139 140 static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, 141 struct ceph_mds_request *req) 142 { 143 struct ceph_mds_request *intr_req; 144 struct inode *inode = req->r_inode; 145 int err, lock_type; 146 147 BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); 148 if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) 149 lock_type = CEPH_LOCK_FCNTL_INTR; 150 else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) 151 lock_type = CEPH_LOCK_FLOCK_INTR; 152 else 153 BUG_ON(1); 154 BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); 155 156 err = wait_for_completion_interruptible(&req->r_completion); 157 if (!err) 158 return 0; 159 160 dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", 161 req->r_tid); 162 163 mutex_lock(&mdsc->mutex); 164 if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { 165 err = 0; 166 } else { 167 /* 168 * ensure we aren't running concurrently with 169 * ceph_fill_trace or ceph_readdir_prepopulate, which 170 * rely on locks (dir mutex) held by our caller. 171 */ 172 mutex_lock(&req->r_fill_mutex); 173 req->r_err = err; 174 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); 175 mutex_unlock(&req->r_fill_mutex); 176 177 if (!req->r_session) { 178 // haven't sent the request 179 err = 0; 180 } 181 } 182 mutex_unlock(&mdsc->mutex); 183 if (!err) 184 return 0; 185 186 intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, 187 USE_AUTH_MDS); 188 if (IS_ERR(intr_req)) 189 return PTR_ERR(intr_req); 190 191 intr_req->r_inode = inode; 192 ihold(inode); 193 intr_req->r_num_caps = 1; 194 195 intr_req->r_args.filelock_change = req->r_args.filelock_change; 196 intr_req->r_args.filelock_change.rule = lock_type; 197 intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; 198 199 err = ceph_mdsc_do_request(mdsc, inode, intr_req); 200 ceph_mdsc_put_request(intr_req); 201 202 if (err && err != -ERESTARTSYS) 203 return err; 204 205 wait_for_completion_killable(&req->r_safe_completion); 206 return 0; 207 } 208 209 /** 210 * Attempt to set an fcntl lock. 211 * For now, this just goes away to the server. Later it may be more awesome. 212 */ 213 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 214 { 215 struct inode *inode = file_inode(file); 216 struct ceph_inode_info *ci = ceph_inode(inode); 217 int err = 0; 218 u16 op = CEPH_MDS_OP_SETFILELOCK; 219 u8 wait = 0; 220 u8 lock_cmd; 221 222 if (!(fl->fl_flags & FL_POSIX)) 223 return -ENOLCK; 224 /* No mandatory locks */ 225 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) 226 return -ENOLCK; 227 228 dout("ceph_lock, fl_owner: %p\n", fl->fl_owner); 229 230 /* set wait bit as appropriate, then make command as Ceph expects it*/ 231 if (IS_GETLK(cmd)) 232 op = CEPH_MDS_OP_GETFILELOCK; 233 else if (IS_SETLKW(cmd)) 234 wait = 1; 235 236 spin_lock(&ci->i_ceph_lock); 237 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 238 err = -EIO; 239 } 240 spin_unlock(&ci->i_ceph_lock); 241 if (err < 0) { 242 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) 243 posix_lock_file(file, fl, NULL); 244 return err; 245 } 246 247 if (F_RDLCK == fl->fl_type) 248 lock_cmd = CEPH_LOCK_SHARED; 249 else if (F_WRLCK == fl->fl_type) 250 lock_cmd = CEPH_LOCK_EXCL; 251 else 252 lock_cmd = CEPH_LOCK_UNLOCK; 253 254 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); 255 if (!err) { 256 if (op == CEPH_MDS_OP_SETFILELOCK) { 257 dout("mds locked, locking locally\n"); 258 err = posix_lock_file(file, fl, NULL); 259 if (err) { 260 /* undo! This should only happen if 261 * the kernel detects local 262 * deadlock. */ 263 ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, 264 CEPH_LOCK_UNLOCK, 0, fl); 265 dout("got %d on posix_lock_file, undid lock\n", 266 err); 267 } 268 } 269 } 270 return err; 271 } 272 273 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 274 { 275 struct inode *inode = file_inode(file); 276 struct ceph_inode_info *ci = ceph_inode(inode); 277 int err = 0; 278 u8 wait = 0; 279 u8 lock_cmd; 280 281 if (!(fl->fl_flags & FL_FLOCK)) 282 return -ENOLCK; 283 /* No mandatory locks */ 284 if (fl->fl_type & LOCK_MAND) 285 return -EOPNOTSUPP; 286 287 dout("ceph_flock, fl_file: %p\n", fl->fl_file); 288 289 spin_lock(&ci->i_ceph_lock); 290 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 291 err = -EIO; 292 } 293 spin_unlock(&ci->i_ceph_lock); 294 if (err < 0) { 295 if (F_UNLCK == fl->fl_type) 296 locks_lock_file_wait(file, fl); 297 return err; 298 } 299 300 if (IS_SETLKW(cmd)) 301 wait = 1; 302 303 if (F_RDLCK == fl->fl_type) 304 lock_cmd = CEPH_LOCK_SHARED; 305 else if (F_WRLCK == fl->fl_type) 306 lock_cmd = CEPH_LOCK_EXCL; 307 else 308 lock_cmd = CEPH_LOCK_UNLOCK; 309 310 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 311 inode, lock_cmd, wait, fl); 312 if (!err) { 313 err = locks_lock_file_wait(file, fl); 314 if (err) { 315 ceph_lock_message(CEPH_LOCK_FLOCK, 316 CEPH_MDS_OP_SETFILELOCK, 317 inode, CEPH_LOCK_UNLOCK, 0, fl); 318 dout("got %d on locks_lock_file_wait, undid lock\n", err); 319 } 320 } 321 return err; 322 } 323 324 /* 325 * Fills in the passed counter variables, so you can prepare pagelist metadata 326 * before calling ceph_encode_locks. 327 */ 328 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 329 { 330 struct file_lock *lock; 331 struct file_lock_context *ctx; 332 333 *fcntl_count = 0; 334 *flock_count = 0; 335 336 ctx = inode->i_flctx; 337 if (ctx) { 338 spin_lock(&ctx->flc_lock); 339 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 340 ++(*fcntl_count); 341 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 342 ++(*flock_count); 343 spin_unlock(&ctx->flc_lock); 344 } 345 dout("counted %d flock locks and %d fcntl locks\n", 346 *flock_count, *fcntl_count); 347 } 348 349 /* 350 * Given a pointer to a lock, convert it to a ceph filelock 351 */ 352 static int lock_to_ceph_filelock(struct file_lock *lock, 353 struct ceph_filelock *cephlock) 354 { 355 int err = 0; 356 cephlock->start = cpu_to_le64(lock->fl_start); 357 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 358 cephlock->client = cpu_to_le64(0); 359 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 360 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 361 362 switch (lock->fl_type) { 363 case F_RDLCK: 364 cephlock->type = CEPH_LOCK_SHARED; 365 break; 366 case F_WRLCK: 367 cephlock->type = CEPH_LOCK_EXCL; 368 break; 369 case F_UNLCK: 370 cephlock->type = CEPH_LOCK_UNLOCK; 371 break; 372 default: 373 dout("Have unknown lock type %d\n", lock->fl_type); 374 err = -EINVAL; 375 } 376 377 return err; 378 } 379 380 /** 381 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 382 * array. Must be called with inode->i_lock already held. 383 * If we encounter more of a specific lock type than expected, return -ENOSPC. 384 */ 385 int ceph_encode_locks_to_buffer(struct inode *inode, 386 struct ceph_filelock *flocks, 387 int num_fcntl_locks, int num_flock_locks) 388 { 389 struct file_lock *lock; 390 struct file_lock_context *ctx = inode->i_flctx; 391 int err = 0; 392 int seen_fcntl = 0; 393 int seen_flock = 0; 394 int l = 0; 395 396 dout("encoding %d flock and %d fcntl locks\n", num_flock_locks, 397 num_fcntl_locks); 398 399 if (!ctx) 400 return 0; 401 402 spin_lock(&ctx->flc_lock); 403 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 404 ++seen_fcntl; 405 if (seen_fcntl > num_fcntl_locks) { 406 err = -ENOSPC; 407 goto fail; 408 } 409 err = lock_to_ceph_filelock(lock, &flocks[l]); 410 if (err) 411 goto fail; 412 ++l; 413 } 414 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 415 ++seen_flock; 416 if (seen_flock > num_flock_locks) { 417 err = -ENOSPC; 418 goto fail; 419 } 420 err = lock_to_ceph_filelock(lock, &flocks[l]); 421 if (err) 422 goto fail; 423 ++l; 424 } 425 fail: 426 spin_unlock(&ctx->flc_lock); 427 return err; 428 } 429 430 /** 431 * Copy the encoded flock and fcntl locks into the pagelist. 432 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 433 * sequential flock locks. 434 * Returns zero on success. 435 */ 436 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 437 struct ceph_pagelist *pagelist, 438 int num_fcntl_locks, int num_flock_locks) 439 { 440 int err = 0; 441 __le32 nlocks; 442 443 nlocks = cpu_to_le32(num_fcntl_locks); 444 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 445 if (err) 446 goto out_fail; 447 448 if (num_fcntl_locks > 0) { 449 err = ceph_pagelist_append(pagelist, flocks, 450 num_fcntl_locks * sizeof(*flocks)); 451 if (err) 452 goto out_fail; 453 } 454 455 nlocks = cpu_to_le32(num_flock_locks); 456 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 457 if (err) 458 goto out_fail; 459 460 if (num_flock_locks > 0) { 461 err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], 462 num_flock_locks * sizeof(*flocks)); 463 } 464 out_fail: 465 return err; 466 } 467