b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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 | } |