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_client(inode->i_sb)->mdsc; 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 /** 214 * Attempt to set an fcntl lock. 215 * For now, this just goes away to the server. Later it may be more awesome. 216 */ 217 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 218 { 219 struct inode *inode = file_inode(file); 220 struct ceph_inode_info *ci = ceph_inode(inode); 221 int err = 0; 222 u16 op = CEPH_MDS_OP_SETFILELOCK; 223 u8 wait = 0; 224 u8 lock_cmd; 225 226 if (!(fl->fl_flags & FL_POSIX)) 227 return -ENOLCK; 228 /* No mandatory locks */ 229 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) 230 return -ENOLCK; 231 232 dout("ceph_lock, fl_owner: %p\n", fl->fl_owner); 233 234 /* set wait bit as appropriate, then make command as Ceph expects it*/ 235 if (IS_GETLK(cmd)) 236 op = CEPH_MDS_OP_GETFILELOCK; 237 else if (IS_SETLKW(cmd)) 238 wait = 1; 239 240 spin_lock(&ci->i_ceph_lock); 241 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 242 err = -EIO; 243 } 244 spin_unlock(&ci->i_ceph_lock); 245 if (err < 0) { 246 if (op == CEPH_MDS_OP_SETFILELOCK && F_UNLCK == fl->fl_type) 247 posix_lock_file(file, fl, NULL); 248 return err; 249 } 250 251 if (F_RDLCK == fl->fl_type) 252 lock_cmd = CEPH_LOCK_SHARED; 253 else if (F_WRLCK == fl->fl_type) 254 lock_cmd = CEPH_LOCK_EXCL; 255 else 256 lock_cmd = CEPH_LOCK_UNLOCK; 257 258 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, lock_cmd, wait, fl); 259 if (!err) { 260 if (op == CEPH_MDS_OP_SETFILELOCK) { 261 dout("mds locked, locking locally\n"); 262 err = posix_lock_file(file, fl, NULL); 263 if (err) { 264 /* undo! This should only happen if 265 * the kernel detects local 266 * deadlock. */ 267 ceph_lock_message(CEPH_LOCK_FCNTL, op, inode, 268 CEPH_LOCK_UNLOCK, 0, fl); 269 dout("got %d on posix_lock_file, undid lock\n", 270 err); 271 } 272 } 273 } 274 return err; 275 } 276 277 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 278 { 279 struct inode *inode = file_inode(file); 280 struct ceph_inode_info *ci = ceph_inode(inode); 281 int err = 0; 282 u8 wait = 0; 283 u8 lock_cmd; 284 285 if (!(fl->fl_flags & FL_FLOCK)) 286 return -ENOLCK; 287 /* No mandatory locks */ 288 if (fl->fl_type & LOCK_MAND) 289 return -EOPNOTSUPP; 290 291 dout("ceph_flock, fl_file: %p\n", fl->fl_file); 292 293 spin_lock(&ci->i_ceph_lock); 294 if (ci->i_ceph_flags & CEPH_I_ERROR_FILELOCK) { 295 err = -EIO; 296 } 297 spin_unlock(&ci->i_ceph_lock); 298 if (err < 0) { 299 if (F_UNLCK == fl->fl_type) 300 locks_lock_file_wait(file, fl); 301 return err; 302 } 303 304 if (IS_SETLKW(cmd)) 305 wait = 1; 306 307 if (F_RDLCK == fl->fl_type) 308 lock_cmd = CEPH_LOCK_SHARED; 309 else if (F_WRLCK == fl->fl_type) 310 lock_cmd = CEPH_LOCK_EXCL; 311 else 312 lock_cmd = CEPH_LOCK_UNLOCK; 313 314 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 315 inode, lock_cmd, wait, fl); 316 if (!err) { 317 err = locks_lock_file_wait(file, fl); 318 if (err) { 319 ceph_lock_message(CEPH_LOCK_FLOCK, 320 CEPH_MDS_OP_SETFILELOCK, 321 inode, CEPH_LOCK_UNLOCK, 0, fl); 322 dout("got %d on locks_lock_file_wait, undid lock\n", err); 323 } 324 } 325 return err; 326 } 327 328 /* 329 * Fills in the passed counter variables, so you can prepare pagelist metadata 330 * before calling ceph_encode_locks. 331 */ 332 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 333 { 334 struct file_lock *lock; 335 struct file_lock_context *ctx; 336 337 *fcntl_count = 0; 338 *flock_count = 0; 339 340 ctx = inode->i_flctx; 341 if (ctx) { 342 spin_lock(&ctx->flc_lock); 343 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 344 ++(*fcntl_count); 345 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 346 ++(*flock_count); 347 spin_unlock(&ctx->flc_lock); 348 } 349 dout("counted %d flock locks and %d fcntl locks\n", 350 *flock_count, *fcntl_count); 351 } 352 353 /* 354 * Given a pointer to a lock, convert it to a ceph filelock 355 */ 356 static int lock_to_ceph_filelock(struct file_lock *lock, 357 struct ceph_filelock *cephlock) 358 { 359 int err = 0; 360 cephlock->start = cpu_to_le64(lock->fl_start); 361 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 362 cephlock->client = cpu_to_le64(0); 363 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 364 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 365 366 switch (lock->fl_type) { 367 case F_RDLCK: 368 cephlock->type = CEPH_LOCK_SHARED; 369 break; 370 case F_WRLCK: 371 cephlock->type = CEPH_LOCK_EXCL; 372 break; 373 case F_UNLCK: 374 cephlock->type = CEPH_LOCK_UNLOCK; 375 break; 376 default: 377 dout("Have unknown lock type %d\n", lock->fl_type); 378 err = -EINVAL; 379 } 380 381 return err; 382 } 383 384 /** 385 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 386 * array. Must be called with inode->i_lock already held. 387 * If we encounter more of a specific lock type than expected, return -ENOSPC. 388 */ 389 int ceph_encode_locks_to_buffer(struct inode *inode, 390 struct ceph_filelock *flocks, 391 int num_fcntl_locks, int num_flock_locks) 392 { 393 struct file_lock *lock; 394 struct file_lock_context *ctx = inode->i_flctx; 395 int err = 0; 396 int seen_fcntl = 0; 397 int seen_flock = 0; 398 int l = 0; 399 400 dout("encoding %d flock and %d fcntl locks\n", num_flock_locks, 401 num_fcntl_locks); 402 403 if (!ctx) 404 return 0; 405 406 spin_lock(&ctx->flc_lock); 407 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 408 ++seen_fcntl; 409 if (seen_fcntl > num_fcntl_locks) { 410 err = -ENOSPC; 411 goto fail; 412 } 413 err = lock_to_ceph_filelock(lock, &flocks[l]); 414 if (err) 415 goto fail; 416 ++l; 417 } 418 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 419 ++seen_flock; 420 if (seen_flock > num_flock_locks) { 421 err = -ENOSPC; 422 goto fail; 423 } 424 err = lock_to_ceph_filelock(lock, &flocks[l]); 425 if (err) 426 goto fail; 427 ++l; 428 } 429 fail: 430 spin_unlock(&ctx->flc_lock); 431 return err; 432 } 433 434 /** 435 * Copy the encoded flock and fcntl locks into the pagelist. 436 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 437 * sequential flock locks. 438 * Returns zero on success. 439 */ 440 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 441 struct ceph_pagelist *pagelist, 442 int num_fcntl_locks, int num_flock_locks) 443 { 444 int err = 0; 445 __le32 nlocks; 446 447 nlocks = cpu_to_le32(num_fcntl_locks); 448 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 449 if (err) 450 goto out_fail; 451 452 if (num_fcntl_locks > 0) { 453 err = ceph_pagelist_append(pagelist, flocks, 454 num_fcntl_locks * sizeof(*flocks)); 455 if (err) 456 goto out_fail; 457 } 458 459 nlocks = cpu_to_le32(num_flock_locks); 460 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 461 if (err) 462 goto out_fail; 463 464 if (num_flock_locks > 0) { 465 err = ceph_pagelist_append(pagelist, &flocks[num_fcntl_locks], 466 num_flock_locks * sizeof(*flocks)); 467 } 468 out_fail: 469 return err; 470 } 471