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 /** 34 * Implement fcntl and flock locking functions. 35 */ 36 static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file, 37 int cmd, u8 wait, struct file_lock *fl) 38 { 39 struct inode *inode = file_inode(file); 40 struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc; 41 struct ceph_mds_request *req; 42 int err; 43 u64 length = 0; 44 u64 owner; 45 46 if (operation != CEPH_MDS_OP_SETFILELOCK || cmd == CEPH_LOCK_UNLOCK) 47 wait = 0; 48 49 req = ceph_mdsc_create_request(mdsc, operation, USE_AUTH_MDS); 50 if (IS_ERR(req)) 51 return PTR_ERR(req); 52 req->r_inode = inode; 53 ihold(inode); 54 req->r_num_caps = 1; 55 56 /* mds requires start and length rather than start and end */ 57 if (LLONG_MAX == fl->fl_end) 58 length = 0; 59 else 60 length = fl->fl_end - fl->fl_start + 1; 61 62 owner = secure_addr(fl->fl_owner); 63 64 dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, " 65 "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type, 66 (int)operation, owner, (u64)fl->fl_pid, fl->fl_start, length, 67 wait, fl->fl_type); 68 69 req->r_args.filelock_change.rule = lock_type; 70 req->r_args.filelock_change.type = cmd; 71 req->r_args.filelock_change.owner = cpu_to_le64(owner); 72 req->r_args.filelock_change.pid = cpu_to_le64((u64)fl->fl_pid); 73 req->r_args.filelock_change.start = cpu_to_le64(fl->fl_start); 74 req->r_args.filelock_change.length = cpu_to_le64(length); 75 req->r_args.filelock_change.wait = wait; 76 77 if (wait) 78 req->r_wait_for_completion = ceph_lock_wait_for_completion; 79 80 err = ceph_mdsc_do_request(mdsc, inode, req); 81 82 if (operation == CEPH_MDS_OP_GETFILELOCK) { 83 fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid); 84 if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type) 85 fl->fl_type = F_RDLCK; 86 else if (CEPH_LOCK_EXCL == req->r_reply_info.filelock_reply->type) 87 fl->fl_type = F_WRLCK; 88 else 89 fl->fl_type = F_UNLCK; 90 91 fl->fl_start = le64_to_cpu(req->r_reply_info.filelock_reply->start); 92 length = le64_to_cpu(req->r_reply_info.filelock_reply->start) + 93 le64_to_cpu(req->r_reply_info.filelock_reply->length); 94 if (length >= 1) 95 fl->fl_end = length -1; 96 else 97 fl->fl_end = 0; 98 99 } 100 ceph_mdsc_put_request(req); 101 dout("ceph_lock_message: rule: %d, op: %d, pid: %llu, start: %llu, " 102 "length: %llu, wait: %d, type: %d, err code %d", (int)lock_type, 103 (int)operation, (u64)fl->fl_pid, fl->fl_start, 104 length, wait, fl->fl_type, err); 105 return err; 106 } 107 108 static int ceph_lock_wait_for_completion(struct ceph_mds_client *mdsc, 109 struct ceph_mds_request *req) 110 { 111 struct ceph_mds_request *intr_req; 112 struct inode *inode = req->r_inode; 113 int err, lock_type; 114 115 BUG_ON(req->r_op != CEPH_MDS_OP_SETFILELOCK); 116 if (req->r_args.filelock_change.rule == CEPH_LOCK_FCNTL) 117 lock_type = CEPH_LOCK_FCNTL_INTR; 118 else if (req->r_args.filelock_change.rule == CEPH_LOCK_FLOCK) 119 lock_type = CEPH_LOCK_FLOCK_INTR; 120 else 121 BUG_ON(1); 122 BUG_ON(req->r_args.filelock_change.type == CEPH_LOCK_UNLOCK); 123 124 err = wait_for_completion_interruptible(&req->r_completion); 125 if (!err) 126 return 0; 127 128 dout("ceph_lock_wait_for_completion: request %llu was interrupted\n", 129 req->r_tid); 130 131 mutex_lock(&mdsc->mutex); 132 if (test_bit(CEPH_MDS_R_GOT_RESULT, &req->r_req_flags)) { 133 err = 0; 134 } else { 135 /* 136 * ensure we aren't running concurrently with 137 * ceph_fill_trace or ceph_readdir_prepopulate, which 138 * rely on locks (dir mutex) held by our caller. 139 */ 140 mutex_lock(&req->r_fill_mutex); 141 req->r_err = err; 142 set_bit(CEPH_MDS_R_ABORTED, &req->r_req_flags); 143 mutex_unlock(&req->r_fill_mutex); 144 145 if (!req->r_session) { 146 // haven't sent the request 147 err = 0; 148 } 149 } 150 mutex_unlock(&mdsc->mutex); 151 if (!err) 152 return 0; 153 154 intr_req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETFILELOCK, 155 USE_AUTH_MDS); 156 if (IS_ERR(intr_req)) 157 return PTR_ERR(intr_req); 158 159 intr_req->r_inode = inode; 160 ihold(inode); 161 intr_req->r_num_caps = 1; 162 163 intr_req->r_args.filelock_change = req->r_args.filelock_change; 164 intr_req->r_args.filelock_change.rule = lock_type; 165 intr_req->r_args.filelock_change.type = CEPH_LOCK_UNLOCK; 166 167 err = ceph_mdsc_do_request(mdsc, inode, intr_req); 168 ceph_mdsc_put_request(intr_req); 169 170 if (err && err != -ERESTARTSYS) 171 return err; 172 173 wait_for_completion_killable(&req->r_safe_completion); 174 return 0; 175 } 176 177 /** 178 * Attempt to set an fcntl lock. 179 * For now, this just goes away to the server. Later it may be more awesome. 180 */ 181 int ceph_lock(struct file *file, int cmd, struct file_lock *fl) 182 { 183 u8 lock_cmd; 184 int err; 185 u8 wait = 0; 186 u16 op = CEPH_MDS_OP_SETFILELOCK; 187 188 if (!(fl->fl_flags & FL_POSIX)) 189 return -ENOLCK; 190 /* No mandatory locks */ 191 if (__mandatory_lock(file->f_mapping->host) && fl->fl_type != F_UNLCK) 192 return -ENOLCK; 193 194 dout("ceph_lock, fl_owner: %p", fl->fl_owner); 195 196 /* set wait bit as appropriate, then make command as Ceph expects it*/ 197 if (IS_GETLK(cmd)) 198 op = CEPH_MDS_OP_GETFILELOCK; 199 else if (IS_SETLKW(cmd)) 200 wait = 1; 201 202 if (F_RDLCK == fl->fl_type) 203 lock_cmd = CEPH_LOCK_SHARED; 204 else if (F_WRLCK == fl->fl_type) 205 lock_cmd = CEPH_LOCK_EXCL; 206 else 207 lock_cmd = CEPH_LOCK_UNLOCK; 208 209 err = ceph_lock_message(CEPH_LOCK_FCNTL, op, file, lock_cmd, wait, fl); 210 if (!err) { 211 if (op != CEPH_MDS_OP_GETFILELOCK) { 212 dout("mds locked, locking locally"); 213 err = posix_lock_file(file, fl, NULL); 214 if (err && (CEPH_MDS_OP_SETFILELOCK == op)) { 215 /* undo! This should only happen if 216 * the kernel detects local 217 * deadlock. */ 218 ceph_lock_message(CEPH_LOCK_FCNTL, op, file, 219 CEPH_LOCK_UNLOCK, 0, fl); 220 dout("got %d on posix_lock_file, undid lock", 221 err); 222 } 223 } 224 } 225 return err; 226 } 227 228 int ceph_flock(struct file *file, int cmd, struct file_lock *fl) 229 { 230 u8 lock_cmd; 231 int err; 232 u8 wait = 0; 233 234 if (!(fl->fl_flags & FL_FLOCK)) 235 return -ENOLCK; 236 /* No mandatory locks */ 237 if (fl->fl_type & LOCK_MAND) 238 return -EOPNOTSUPP; 239 240 dout("ceph_flock, fl_file: %p", fl->fl_file); 241 242 if (IS_SETLKW(cmd)) 243 wait = 1; 244 245 if (F_RDLCK == fl->fl_type) 246 lock_cmd = CEPH_LOCK_SHARED; 247 else if (F_WRLCK == fl->fl_type) 248 lock_cmd = CEPH_LOCK_EXCL; 249 else 250 lock_cmd = CEPH_LOCK_UNLOCK; 251 252 err = ceph_lock_message(CEPH_LOCK_FLOCK, CEPH_MDS_OP_SETFILELOCK, 253 file, lock_cmd, wait, fl); 254 if (!err) { 255 err = locks_lock_file_wait(file, fl); 256 if (err) { 257 ceph_lock_message(CEPH_LOCK_FLOCK, 258 CEPH_MDS_OP_SETFILELOCK, 259 file, CEPH_LOCK_UNLOCK, 0, fl); 260 dout("got %d on locks_lock_file_wait, undid lock", err); 261 } 262 } 263 return err; 264 } 265 266 /* 267 * Fills in the passed counter variables, so you can prepare pagelist metadata 268 * before calling ceph_encode_locks. 269 */ 270 void ceph_count_locks(struct inode *inode, int *fcntl_count, int *flock_count) 271 { 272 struct file_lock *lock; 273 struct file_lock_context *ctx; 274 275 *fcntl_count = 0; 276 *flock_count = 0; 277 278 ctx = inode->i_flctx; 279 if (ctx) { 280 spin_lock(&ctx->flc_lock); 281 list_for_each_entry(lock, &ctx->flc_posix, fl_list) 282 ++(*fcntl_count); 283 list_for_each_entry(lock, &ctx->flc_flock, fl_list) 284 ++(*flock_count); 285 spin_unlock(&ctx->flc_lock); 286 } 287 dout("counted %d flock locks and %d fcntl locks", 288 *flock_count, *fcntl_count); 289 } 290 291 /** 292 * Encode the flock and fcntl locks for the given inode into the ceph_filelock 293 * array. Must be called with inode->i_lock already held. 294 * If we encounter more of a specific lock type than expected, return -ENOSPC. 295 */ 296 int ceph_encode_locks_to_buffer(struct inode *inode, 297 struct ceph_filelock *flocks, 298 int num_fcntl_locks, int num_flock_locks) 299 { 300 struct file_lock *lock; 301 struct file_lock_context *ctx = inode->i_flctx; 302 int err = 0; 303 int seen_fcntl = 0; 304 int seen_flock = 0; 305 int l = 0; 306 307 dout("encoding %d flock and %d fcntl locks", num_flock_locks, 308 num_fcntl_locks); 309 310 if (!ctx) 311 return 0; 312 313 spin_lock(&ctx->flc_lock); 314 list_for_each_entry(lock, &ctx->flc_posix, fl_list) { 315 ++seen_fcntl; 316 if (seen_fcntl > num_fcntl_locks) { 317 err = -ENOSPC; 318 goto fail; 319 } 320 err = lock_to_ceph_filelock(lock, &flocks[l]); 321 if (err) 322 goto fail; 323 ++l; 324 } 325 list_for_each_entry(lock, &ctx->flc_flock, fl_list) { 326 ++seen_flock; 327 if (seen_flock > num_flock_locks) { 328 err = -ENOSPC; 329 goto fail; 330 } 331 err = lock_to_ceph_filelock(lock, &flocks[l]); 332 if (err) 333 goto fail; 334 ++l; 335 } 336 fail: 337 spin_unlock(&ctx->flc_lock); 338 return err; 339 } 340 341 /** 342 * Copy the encoded flock and fcntl locks into the pagelist. 343 * Format is: #fcntl locks, sequential fcntl locks, #flock locks, 344 * sequential flock locks. 345 * Returns zero on success. 346 */ 347 int ceph_locks_to_pagelist(struct ceph_filelock *flocks, 348 struct ceph_pagelist *pagelist, 349 int num_fcntl_locks, int num_flock_locks) 350 { 351 int err = 0; 352 __le32 nlocks; 353 354 nlocks = cpu_to_le32(num_fcntl_locks); 355 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 356 if (err) 357 goto out_fail; 358 359 err = ceph_pagelist_append(pagelist, flocks, 360 num_fcntl_locks * sizeof(*flocks)); 361 if (err) 362 goto out_fail; 363 364 nlocks = cpu_to_le32(num_flock_locks); 365 err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks)); 366 if (err) 367 goto out_fail; 368 369 err = ceph_pagelist_append(pagelist, 370 &flocks[num_fcntl_locks], 371 num_flock_locks * sizeof(*flocks)); 372 out_fail: 373 return err; 374 } 375 376 /* 377 * Given a pointer to a lock, convert it to a ceph filelock 378 */ 379 int lock_to_ceph_filelock(struct file_lock *lock, 380 struct ceph_filelock *cephlock) 381 { 382 int err = 0; 383 cephlock->start = cpu_to_le64(lock->fl_start); 384 cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1); 385 cephlock->client = cpu_to_le64(0); 386 cephlock->pid = cpu_to_le64((u64)lock->fl_pid); 387 cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner)); 388 389 switch (lock->fl_type) { 390 case F_RDLCK: 391 cephlock->type = CEPH_LOCK_SHARED; 392 break; 393 case F_WRLCK: 394 cephlock->type = CEPH_LOCK_EXCL; 395 break; 396 case F_UNLCK: 397 cephlock->type = CEPH_LOCK_UNLOCK; 398 break; 399 default: 400 dout("Have unknown lock type %d", lock->fl_type); 401 err = -EINVAL; 402 } 403 404 return err; 405 } 406