b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright 2020 Google LLC |
| 4 | */ |
| 5 | |
| 6 | #include <linux/file.h> |
| 7 | #include <linux/fs.h> |
| 8 | #include <linux/fsnotify.h> |
| 9 | #include <linux/namei.h> |
| 10 | #include <linux/poll.h> |
| 11 | #include <linux/syscalls.h> |
| 12 | |
| 13 | #include <uapi/linux/incrementalfs.h> |
| 14 | |
| 15 | #include "pseudo_files.h" |
| 16 | |
| 17 | #include "data_mgmt.h" |
| 18 | #include "format.h" |
| 19 | #include "integrity.h" |
| 20 | #include "vfs.h" |
| 21 | |
| 22 | #define READ_WRITE_FILE_MODE 0666 |
| 23 | |
| 24 | static bool is_pseudo_filename(struct mem_range name); |
| 25 | |
| 26 | /******************************************************************************* |
| 27 | * .pending_reads pseudo file definition |
| 28 | ******************************************************************************/ |
| 29 | #define INCFS_PENDING_READS_INODE 2 |
| 30 | static const char pending_reads_file_name[] = INCFS_PENDING_READS_FILENAME; |
| 31 | |
| 32 | /* State of an open .pending_reads file, unique for each file descriptor. */ |
| 33 | struct pending_reads_state { |
| 34 | /* A serial number of the last pending read obtained from this file. */ |
| 35 | int last_pending_read_sn; |
| 36 | }; |
| 37 | |
| 38 | static ssize_t pending_reads_read(struct file *f, char __user *buf, size_t len, |
| 39 | loff_t *ppos) |
| 40 | { |
| 41 | struct pending_reads_state *pr_state = f->private_data; |
| 42 | struct mount_info *mi = get_mount_info(file_superblock(f)); |
| 43 | bool report_uid; |
| 44 | unsigned long page = 0; |
| 45 | struct incfs_pending_read_info *reads_buf = NULL; |
| 46 | struct incfs_pending_read_info2 *reads_buf2 = NULL; |
| 47 | size_t record_size; |
| 48 | size_t reads_to_collect; |
| 49 | int last_known_read_sn = READ_ONCE(pr_state->last_pending_read_sn); |
| 50 | int new_max_sn = last_known_read_sn; |
| 51 | int reads_collected = 0; |
| 52 | ssize_t result = 0; |
| 53 | |
| 54 | if (!mi) |
| 55 | return -EFAULT; |
| 56 | |
| 57 | report_uid = mi->mi_options.report_uid; |
| 58 | record_size = report_uid ? sizeof(*reads_buf2) : sizeof(*reads_buf); |
| 59 | reads_to_collect = len / record_size; |
| 60 | |
| 61 | if (!incfs_fresh_pending_reads_exist(mi, last_known_read_sn)) |
| 62 | return 0; |
| 63 | |
| 64 | page = get_zeroed_page(GFP_NOFS); |
| 65 | if (!page) |
| 66 | return -ENOMEM; |
| 67 | |
| 68 | if (report_uid) |
| 69 | reads_buf2 = (struct incfs_pending_read_info2 *) page; |
| 70 | else |
| 71 | reads_buf = (struct incfs_pending_read_info *) page; |
| 72 | |
| 73 | reads_to_collect = |
| 74 | min_t(size_t, PAGE_SIZE / record_size, reads_to_collect); |
| 75 | |
| 76 | reads_collected = incfs_collect_pending_reads(mi, last_known_read_sn, |
| 77 | reads_buf, reads_buf2, reads_to_collect, |
| 78 | &new_max_sn); |
| 79 | |
| 80 | if (reads_collected < 0) { |
| 81 | result = reads_collected; |
| 82 | goto out; |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Just to make sure that we don't accidentally copy more data |
| 87 | * to reads buffer than userspace can handle. |
| 88 | */ |
| 89 | reads_collected = min_t(size_t, reads_collected, reads_to_collect); |
| 90 | result = reads_collected * record_size; |
| 91 | |
| 92 | /* Copy reads info to the userspace buffer */ |
| 93 | if (copy_to_user(buf, (void *)page, result)) { |
| 94 | result = -EFAULT; |
| 95 | goto out; |
| 96 | } |
| 97 | |
| 98 | WRITE_ONCE(pr_state->last_pending_read_sn, new_max_sn); |
| 99 | *ppos = 0; |
| 100 | |
| 101 | out: |
| 102 | free_page(page); |
| 103 | return result; |
| 104 | } |
| 105 | |
| 106 | static __poll_t pending_reads_poll(struct file *file, poll_table *wait) |
| 107 | { |
| 108 | struct pending_reads_state *state = file->private_data; |
| 109 | struct mount_info *mi = get_mount_info(file_superblock(file)); |
| 110 | __poll_t ret = 0; |
| 111 | |
| 112 | poll_wait(file, &mi->mi_pending_reads_notif_wq, wait); |
| 113 | if (incfs_fresh_pending_reads_exist(mi, |
| 114 | state->last_pending_read_sn)) |
| 115 | ret = EPOLLIN | EPOLLRDNORM; |
| 116 | |
| 117 | return ret; |
| 118 | } |
| 119 | |
| 120 | static int pending_reads_open(struct inode *inode, struct file *file) |
| 121 | { |
| 122 | struct pending_reads_state *state = NULL; |
| 123 | |
| 124 | state = kzalloc(sizeof(*state), GFP_NOFS); |
| 125 | if (!state) |
| 126 | return -ENOMEM; |
| 127 | |
| 128 | file->private_data = state; |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | static int pending_reads_release(struct inode *inode, struct file *file) |
| 133 | { |
| 134 | kfree(file->private_data); |
| 135 | return 0; |
| 136 | } |
| 137 | |
| 138 | static long ioctl_permit_fill(struct file *f, void __user *arg) |
| 139 | { |
| 140 | struct incfs_permit_fill __user *usr_permit_fill = arg; |
| 141 | struct incfs_permit_fill permit_fill; |
| 142 | long error = 0; |
| 143 | struct file *file = NULL; |
| 144 | struct incfs_file_data *fd; |
| 145 | |
| 146 | if (copy_from_user(&permit_fill, usr_permit_fill, sizeof(permit_fill))) |
| 147 | return -EFAULT; |
| 148 | |
| 149 | file = fget(permit_fill.file_descriptor); |
| 150 | if (IS_ERR_OR_NULL(file)) { |
| 151 | if (!file) |
| 152 | return -ENOENT; |
| 153 | |
| 154 | return PTR_ERR(file); |
| 155 | } |
| 156 | |
| 157 | if (file->f_op != &incfs_file_ops) { |
| 158 | error = -EPERM; |
| 159 | goto out; |
| 160 | } |
| 161 | |
| 162 | if (file->f_inode->i_sb != f->f_inode->i_sb) { |
| 163 | error = -EPERM; |
| 164 | goto out; |
| 165 | } |
| 166 | |
| 167 | fd = file->private_data; |
| 168 | |
| 169 | switch (fd->fd_fill_permission) { |
| 170 | case CANT_FILL: |
| 171 | fd->fd_fill_permission = CAN_FILL; |
| 172 | break; |
| 173 | |
| 174 | case CAN_FILL: |
| 175 | pr_debug("CAN_FILL already set"); |
| 176 | break; |
| 177 | |
| 178 | default: |
| 179 | pr_warn("Invalid file private data"); |
| 180 | error = -EFAULT; |
| 181 | goto out; |
| 182 | } |
| 183 | |
| 184 | out: |
| 185 | fput(file); |
| 186 | return error; |
| 187 | } |
| 188 | |
| 189 | static int chmod(struct dentry *dentry, umode_t mode) |
| 190 | { |
| 191 | struct inode *inode = dentry->d_inode; |
| 192 | struct inode *delegated_inode = NULL; |
| 193 | struct iattr newattrs; |
| 194 | int error; |
| 195 | |
| 196 | retry_deleg: |
| 197 | inode_lock(inode); |
| 198 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
| 199 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; |
| 200 | error = notify_change(dentry, &newattrs, &delegated_inode); |
| 201 | inode_unlock(inode); |
| 202 | if (delegated_inode) { |
| 203 | error = break_deleg_wait(&delegated_inode); |
| 204 | if (!error) |
| 205 | goto retry_deleg; |
| 206 | } |
| 207 | return error; |
| 208 | } |
| 209 | |
| 210 | static bool incfs_equal_ranges(struct mem_range lhs, struct mem_range rhs) |
| 211 | { |
| 212 | if (lhs.len != rhs.len) |
| 213 | return false; |
| 214 | return memcmp(lhs.data, rhs.data, lhs.len) == 0; |
| 215 | } |
| 216 | |
| 217 | static int validate_name(char *file_name) |
| 218 | { |
| 219 | struct mem_range name = range(file_name, strlen(file_name)); |
| 220 | int i = 0; |
| 221 | |
| 222 | if (name.len > INCFS_MAX_NAME_LEN) |
| 223 | return -ENAMETOOLONG; |
| 224 | |
| 225 | if (is_pseudo_filename(name)) |
| 226 | return -EINVAL; |
| 227 | |
| 228 | for (i = 0; i < name.len; i++) |
| 229 | if (name.data[i] == '/') |
| 230 | return -EINVAL; |
| 231 | |
| 232 | return 0; |
| 233 | } |
| 234 | |
| 235 | static int dir_relative_path_resolve( |
| 236 | struct mount_info *mi, |
| 237 | const char __user *relative_path, |
| 238 | struct path *result_path, |
| 239 | struct path *base_path) |
| 240 | { |
| 241 | int dir_fd = get_unused_fd_flags(0); |
| 242 | struct file *dir_f = NULL; |
| 243 | int error = 0; |
| 244 | |
| 245 | if (!base_path) |
| 246 | base_path = &mi->mi_backing_dir_path; |
| 247 | |
| 248 | if (dir_fd < 0) |
| 249 | return dir_fd; |
| 250 | |
| 251 | dir_f = dentry_open(base_path, O_RDONLY | O_NOATIME, current_cred()); |
| 252 | |
| 253 | if (IS_ERR(dir_f)) { |
| 254 | error = PTR_ERR(dir_f); |
| 255 | goto out; |
| 256 | } |
| 257 | fd_install(dir_fd, dir_f); |
| 258 | |
| 259 | if (!relative_path) { |
| 260 | /* No relative path given, just return the base dir. */ |
| 261 | *result_path = *base_path; |
| 262 | path_get(result_path); |
| 263 | goto out; |
| 264 | } |
| 265 | |
| 266 | error = user_path_at_empty(dir_fd, relative_path, |
| 267 | LOOKUP_FOLLOW | LOOKUP_DIRECTORY, result_path, NULL); |
| 268 | |
| 269 | out: |
| 270 | ksys_close(dir_fd); |
| 271 | if (error) |
| 272 | pr_debug("Error: %d\n", error); |
| 273 | return error; |
| 274 | } |
| 275 | |
| 276 | static struct mem_range incfs_copy_signature_info_from_user(u8 __user *original, |
| 277 | u64 size) |
| 278 | { |
| 279 | u8 *result; |
| 280 | |
| 281 | if (!original) |
| 282 | return range(NULL, 0); |
| 283 | |
| 284 | if (size > INCFS_MAX_SIGNATURE_SIZE) |
| 285 | return range(ERR_PTR(-EFAULT), 0); |
| 286 | |
| 287 | result = kzalloc(size, GFP_NOFS | __GFP_COMP); |
| 288 | if (!result) |
| 289 | return range(ERR_PTR(-ENOMEM), 0); |
| 290 | |
| 291 | if (copy_from_user(result, original, size)) { |
| 292 | kfree(result); |
| 293 | return range(ERR_PTR(-EFAULT), 0); |
| 294 | } |
| 295 | |
| 296 | return range(result, size); |
| 297 | } |
| 298 | |
| 299 | static int init_new_file(struct mount_info *mi, struct dentry *dentry, |
| 300 | incfs_uuid_t *uuid, u64 size, struct mem_range attr, |
| 301 | u8 __user *user_signature_info, u64 signature_size) |
| 302 | { |
| 303 | struct path path = {}; |
| 304 | struct file *new_file; |
| 305 | int error = 0; |
| 306 | struct backing_file_context *bfc = NULL; |
| 307 | u32 block_count; |
| 308 | struct mem_range raw_signature = { NULL }; |
| 309 | struct mtree *hash_tree = NULL; |
| 310 | |
| 311 | if (!mi || !dentry || !uuid) |
| 312 | return -EFAULT; |
| 313 | |
| 314 | /* Resize newly created file to its true size. */ |
| 315 | path = (struct path) { |
| 316 | .mnt = mi->mi_backing_dir_path.mnt, |
| 317 | .dentry = dentry |
| 318 | }; |
| 319 | |
| 320 | new_file = dentry_open(&path, O_RDWR | O_NOATIME | O_LARGEFILE, |
| 321 | current_cred()); |
| 322 | |
| 323 | if (IS_ERR(new_file)) { |
| 324 | error = PTR_ERR(new_file); |
| 325 | goto out; |
| 326 | } |
| 327 | |
| 328 | bfc = incfs_alloc_bfc(mi, new_file); |
| 329 | fput(new_file); |
| 330 | if (IS_ERR(bfc)) { |
| 331 | error = PTR_ERR(bfc); |
| 332 | bfc = NULL; |
| 333 | goto out; |
| 334 | } |
| 335 | |
| 336 | mutex_lock(&bfc->bc_mutex); |
| 337 | error = incfs_write_fh_to_backing_file(bfc, uuid, size); |
| 338 | if (error) |
| 339 | goto out; |
| 340 | |
| 341 | block_count = (u32)get_blocks_count_for_size(size); |
| 342 | |
| 343 | if (user_signature_info) { |
| 344 | raw_signature = incfs_copy_signature_info_from_user( |
| 345 | user_signature_info, signature_size); |
| 346 | |
| 347 | if (IS_ERR(raw_signature.data)) { |
| 348 | error = PTR_ERR(raw_signature.data); |
| 349 | raw_signature.data = NULL; |
| 350 | goto out; |
| 351 | } |
| 352 | |
| 353 | hash_tree = incfs_alloc_mtree(raw_signature, block_count); |
| 354 | if (IS_ERR(hash_tree)) { |
| 355 | error = PTR_ERR(hash_tree); |
| 356 | hash_tree = NULL; |
| 357 | goto out; |
| 358 | } |
| 359 | |
| 360 | error = incfs_write_signature_to_backing_file(bfc, |
| 361 | raw_signature, hash_tree->hash_tree_area_size, |
| 362 | NULL, NULL); |
| 363 | if (error) |
| 364 | goto out; |
| 365 | |
| 366 | block_count += get_blocks_count_for_size( |
| 367 | hash_tree->hash_tree_area_size); |
| 368 | } |
| 369 | |
| 370 | if (block_count) |
| 371 | error = incfs_write_blockmap_to_backing_file(bfc, block_count); |
| 372 | |
| 373 | if (error) |
| 374 | goto out; |
| 375 | |
| 376 | out: |
| 377 | if (bfc) { |
| 378 | mutex_unlock(&bfc->bc_mutex); |
| 379 | incfs_free_bfc(bfc); |
| 380 | } |
| 381 | incfs_free_mtree(hash_tree); |
| 382 | kfree(raw_signature.data); |
| 383 | |
| 384 | if (error) |
| 385 | pr_debug("incfs: %s error: %d\n", __func__, error); |
| 386 | return error; |
| 387 | } |
| 388 | |
| 389 | static void notify_create(struct file *pending_reads_file, |
| 390 | const char __user *dir_name, const char *file_name, |
| 391 | const char *file_id_str, bool incomplete_file) |
| 392 | { |
| 393 | struct mount_info *mi = |
| 394 | get_mount_info(file_superblock(pending_reads_file)); |
| 395 | struct path base_path = { |
| 396 | .mnt = pending_reads_file->f_path.mnt, |
| 397 | .dentry = pending_reads_file->f_path.dentry->d_parent, |
| 398 | }; |
| 399 | struct path dir_path = {}; |
| 400 | struct dentry *file = NULL; |
| 401 | struct dentry *dir = NULL; |
| 402 | int error; |
| 403 | |
| 404 | error = dir_relative_path_resolve(mi, dir_name, &dir_path, &base_path); |
| 405 | if (error) |
| 406 | goto out; |
| 407 | |
| 408 | file = incfs_lookup_dentry(dir_path.dentry, file_name); |
| 409 | if (IS_ERR(file)) { |
| 410 | error = PTR_ERR(file); |
| 411 | file = NULL; |
| 412 | goto out; |
| 413 | } |
| 414 | |
| 415 | fsnotify_create(d_inode(dir_path.dentry), file); |
| 416 | |
| 417 | if (file_id_str) { |
| 418 | dir = incfs_lookup_dentry(base_path.dentry, INCFS_INDEX_NAME); |
| 419 | if (IS_ERR(dir)) { |
| 420 | error = PTR_ERR(dir); |
| 421 | dir = NULL; |
| 422 | goto out; |
| 423 | } |
| 424 | |
| 425 | dput(file); |
| 426 | file = incfs_lookup_dentry(dir, file_id_str); |
| 427 | if (IS_ERR(file)) { |
| 428 | error = PTR_ERR(file); |
| 429 | file = NULL; |
| 430 | goto out; |
| 431 | } |
| 432 | |
| 433 | fsnotify_create(d_inode(dir), file); |
| 434 | |
| 435 | if (incomplete_file) { |
| 436 | dput(dir); |
| 437 | dir = incfs_lookup_dentry(base_path.dentry, |
| 438 | INCFS_INCOMPLETE_NAME); |
| 439 | if (IS_ERR(dir)) { |
| 440 | error = PTR_ERR(dir); |
| 441 | dir = NULL; |
| 442 | goto out; |
| 443 | } |
| 444 | |
| 445 | dput(file); |
| 446 | file = incfs_lookup_dentry(dir, file_id_str); |
| 447 | if (IS_ERR(file)) { |
| 448 | error = PTR_ERR(file); |
| 449 | file = NULL; |
| 450 | goto out; |
| 451 | } |
| 452 | |
| 453 | fsnotify_create(d_inode(dir), file); |
| 454 | } |
| 455 | } |
| 456 | out: |
| 457 | if (error) |
| 458 | pr_warn("%s failed with error %d\n", __func__, error); |
| 459 | |
| 460 | dput(dir); |
| 461 | dput(file); |
| 462 | path_put(&dir_path); |
| 463 | } |
| 464 | |
| 465 | static long ioctl_create_file(struct file *file, |
| 466 | struct incfs_new_file_args __user *usr_args) |
| 467 | { |
| 468 | struct mount_info *mi = get_mount_info(file_superblock(file)); |
| 469 | struct incfs_new_file_args args; |
| 470 | char *file_id_str = NULL; |
| 471 | struct dentry *index_file_dentry = NULL; |
| 472 | struct dentry *named_file_dentry = NULL; |
| 473 | struct dentry *incomplete_file_dentry = NULL; |
| 474 | struct path parent_dir_path = {}; |
| 475 | struct inode *index_dir_inode = NULL; |
| 476 | __le64 size_attr_value = 0; |
| 477 | char *file_name = NULL; |
| 478 | char *attr_value = NULL; |
| 479 | int error = 0; |
| 480 | bool locked = false; |
| 481 | bool index_linked = false; |
| 482 | bool name_linked = false; |
| 483 | bool incomplete_linked = false; |
| 484 | |
| 485 | if (!mi || !mi->mi_index_dir || !mi->mi_incomplete_dir) { |
| 486 | error = -EFAULT; |
| 487 | goto out; |
| 488 | } |
| 489 | |
| 490 | if (copy_from_user(&args, usr_args, sizeof(args)) > 0) { |
| 491 | error = -EFAULT; |
| 492 | goto out; |
| 493 | } |
| 494 | |
| 495 | file_name = strndup_user(u64_to_user_ptr(args.file_name), PATH_MAX); |
| 496 | if (IS_ERR(file_name)) { |
| 497 | error = PTR_ERR(file_name); |
| 498 | file_name = NULL; |
| 499 | goto out; |
| 500 | } |
| 501 | |
| 502 | error = validate_name(file_name); |
| 503 | if (error) |
| 504 | goto out; |
| 505 | |
| 506 | file_id_str = file_id_to_str(args.file_id); |
| 507 | if (!file_id_str) { |
| 508 | error = -ENOMEM; |
| 509 | goto out; |
| 510 | } |
| 511 | |
| 512 | error = mutex_lock_interruptible(&mi->mi_dir_struct_mutex); |
| 513 | if (error) |
| 514 | goto out; |
| 515 | locked = true; |
| 516 | |
| 517 | /* Find a directory to put the file into. */ |
| 518 | error = dir_relative_path_resolve(mi, |
| 519 | u64_to_user_ptr(args.directory_path), |
| 520 | &parent_dir_path, NULL); |
| 521 | if (error) |
| 522 | goto out; |
| 523 | |
| 524 | if (parent_dir_path.dentry == mi->mi_index_dir) { |
| 525 | /* Can't create a file directly inside .index */ |
| 526 | error = -EBUSY; |
| 527 | goto out; |
| 528 | } |
| 529 | |
| 530 | if (parent_dir_path.dentry == mi->mi_incomplete_dir) { |
| 531 | /* Can't create a file directly inside .incomplete */ |
| 532 | error = -EBUSY; |
| 533 | goto out; |
| 534 | } |
| 535 | |
| 536 | /* Look up a dentry in the parent dir. It should be negative. */ |
| 537 | named_file_dentry = incfs_lookup_dentry(parent_dir_path.dentry, |
| 538 | file_name); |
| 539 | if (!named_file_dentry) { |
| 540 | error = -EFAULT; |
| 541 | goto out; |
| 542 | } |
| 543 | if (IS_ERR(named_file_dentry)) { |
| 544 | error = PTR_ERR(named_file_dentry); |
| 545 | named_file_dentry = NULL; |
| 546 | goto out; |
| 547 | } |
| 548 | if (d_really_is_positive(named_file_dentry)) { |
| 549 | /* File with this path already exists. */ |
| 550 | error = -EEXIST; |
| 551 | goto out; |
| 552 | } |
| 553 | |
| 554 | /* Look up a dentry in the incomplete dir. It should be negative. */ |
| 555 | incomplete_file_dentry = incfs_lookup_dentry(mi->mi_incomplete_dir, |
| 556 | file_id_str); |
| 557 | if (!incomplete_file_dentry) { |
| 558 | error = -EFAULT; |
| 559 | goto out; |
| 560 | } |
| 561 | if (IS_ERR(incomplete_file_dentry)) { |
| 562 | error = PTR_ERR(incomplete_file_dentry); |
| 563 | incomplete_file_dentry = NULL; |
| 564 | goto out; |
| 565 | } |
| 566 | if (d_really_is_positive(incomplete_file_dentry)) { |
| 567 | /* File with this path already exists. */ |
| 568 | error = -EEXIST; |
| 569 | goto out; |
| 570 | } |
| 571 | |
| 572 | /* Look up a dentry in the .index dir. It should be negative. */ |
| 573 | index_file_dentry = incfs_lookup_dentry(mi->mi_index_dir, file_id_str); |
| 574 | if (!index_file_dentry) { |
| 575 | error = -EFAULT; |
| 576 | goto out; |
| 577 | } |
| 578 | if (IS_ERR(index_file_dentry)) { |
| 579 | error = PTR_ERR(index_file_dentry); |
| 580 | index_file_dentry = NULL; |
| 581 | goto out; |
| 582 | } |
| 583 | if (d_really_is_positive(index_file_dentry)) { |
| 584 | /* File with this ID already exists in index. */ |
| 585 | error = -EEXIST; |
| 586 | goto out; |
| 587 | } |
| 588 | |
| 589 | /* Creating a file in the .index dir. */ |
| 590 | index_dir_inode = d_inode(mi->mi_index_dir); |
| 591 | inode_lock_nested(index_dir_inode, I_MUTEX_PARENT); |
| 592 | error = vfs_create(index_dir_inode, index_file_dentry, args.mode | 0222, |
| 593 | true); |
| 594 | inode_unlock(index_dir_inode); |
| 595 | |
| 596 | if (error) |
| 597 | goto out; |
| 598 | if (!d_really_is_positive(index_file_dentry)) { |
| 599 | error = -EINVAL; |
| 600 | goto out; |
| 601 | } |
| 602 | |
| 603 | error = chmod(index_file_dentry, args.mode | 0222); |
| 604 | if (error) { |
| 605 | pr_debug("incfs: chmod err: %d\n", error); |
| 606 | goto out; |
| 607 | } |
| 608 | |
| 609 | /* Save the file's ID as an xattr for easy fetching in future. */ |
| 610 | error = vfs_setxattr(index_file_dentry, INCFS_XATTR_ID_NAME, |
| 611 | file_id_str, strlen(file_id_str), XATTR_CREATE); |
| 612 | if (error) { |
| 613 | pr_debug("incfs: vfs_setxattr err:%d\n", error); |
| 614 | goto out; |
| 615 | } |
| 616 | |
| 617 | /* Save the file's size as an xattr for easy fetching in future. */ |
| 618 | size_attr_value = cpu_to_le64(args.size); |
| 619 | error = vfs_setxattr(index_file_dentry, INCFS_XATTR_SIZE_NAME, |
| 620 | (char *)&size_attr_value, sizeof(size_attr_value), |
| 621 | XATTR_CREATE); |
| 622 | if (error) { |
| 623 | pr_debug("incfs: vfs_setxattr err:%d\n", error); |
| 624 | goto out; |
| 625 | } |
| 626 | |
| 627 | /* Save the file's attribute as an xattr */ |
| 628 | if (args.file_attr_len && args.file_attr) { |
| 629 | if (args.file_attr_len > INCFS_MAX_FILE_ATTR_SIZE) { |
| 630 | error = -E2BIG; |
| 631 | goto out; |
| 632 | } |
| 633 | |
| 634 | attr_value = kmalloc(args.file_attr_len, GFP_NOFS); |
| 635 | if (!attr_value) { |
| 636 | error = -ENOMEM; |
| 637 | goto out; |
| 638 | } |
| 639 | |
| 640 | if (copy_from_user(attr_value, |
| 641 | u64_to_user_ptr(args.file_attr), |
| 642 | args.file_attr_len) > 0) { |
| 643 | error = -EFAULT; |
| 644 | goto out; |
| 645 | } |
| 646 | |
| 647 | error = vfs_setxattr(index_file_dentry, |
| 648 | INCFS_XATTR_METADATA_NAME, |
| 649 | attr_value, args.file_attr_len, |
| 650 | XATTR_CREATE); |
| 651 | |
| 652 | if (error) |
| 653 | goto out; |
| 654 | } |
| 655 | |
| 656 | /* Initializing a newly created file. */ |
| 657 | error = init_new_file(mi, index_file_dentry, &args.file_id, args.size, |
| 658 | range(attr_value, args.file_attr_len), |
| 659 | u64_to_user_ptr(args.signature_info), |
| 660 | args.signature_size); |
| 661 | if (error) |
| 662 | goto out; |
| 663 | index_linked = true; |
| 664 | |
| 665 | /* Linking a file with its real name from the requested dir. */ |
| 666 | error = incfs_link(index_file_dentry, named_file_dentry); |
| 667 | if (error) |
| 668 | goto out; |
| 669 | name_linked = true; |
| 670 | |
| 671 | if (args.size) { |
| 672 | /* Linking a file with its incomplete entry */ |
| 673 | error = incfs_link(index_file_dentry, incomplete_file_dentry); |
| 674 | if (error) |
| 675 | goto out; |
| 676 | incomplete_linked = true; |
| 677 | } |
| 678 | |
| 679 | notify_create(file, u64_to_user_ptr(args.directory_path), file_name, |
| 680 | file_id_str, args.size != 0); |
| 681 | |
| 682 | out: |
| 683 | if (error) { |
| 684 | pr_debug("incfs: %s err:%d\n", __func__, error); |
| 685 | if (index_linked) |
| 686 | incfs_unlink(index_file_dentry); |
| 687 | if (name_linked) |
| 688 | incfs_unlink(named_file_dentry); |
| 689 | if (incomplete_linked) |
| 690 | incfs_unlink(incomplete_file_dentry); |
| 691 | } |
| 692 | |
| 693 | kfree(file_id_str); |
| 694 | kfree(file_name); |
| 695 | kfree(attr_value); |
| 696 | dput(named_file_dentry); |
| 697 | dput(index_file_dentry); |
| 698 | dput(incomplete_file_dentry); |
| 699 | path_put(&parent_dir_path); |
| 700 | if (locked) |
| 701 | mutex_unlock(&mi->mi_dir_struct_mutex); |
| 702 | |
| 703 | return error; |
| 704 | } |
| 705 | |
| 706 | static int init_new_mapped_file(struct mount_info *mi, struct dentry *dentry, |
| 707 | incfs_uuid_t *uuid, u64 size, u64 offset) |
| 708 | { |
| 709 | struct path path = {}; |
| 710 | struct file *new_file; |
| 711 | int error = 0; |
| 712 | struct backing_file_context *bfc = NULL; |
| 713 | |
| 714 | if (!mi || !dentry || !uuid) |
| 715 | return -EFAULT; |
| 716 | |
| 717 | /* Resize newly created file to its true size. */ |
| 718 | path = (struct path) { |
| 719 | .mnt = mi->mi_backing_dir_path.mnt, |
| 720 | .dentry = dentry |
| 721 | }; |
| 722 | new_file = dentry_open(&path, O_RDWR | O_NOATIME | O_LARGEFILE, |
| 723 | current_cred()); |
| 724 | |
| 725 | if (IS_ERR(new_file)) { |
| 726 | error = PTR_ERR(new_file); |
| 727 | goto out; |
| 728 | } |
| 729 | |
| 730 | bfc = incfs_alloc_bfc(mi, new_file); |
| 731 | fput(new_file); |
| 732 | if (IS_ERR(bfc)) { |
| 733 | error = PTR_ERR(bfc); |
| 734 | bfc = NULL; |
| 735 | goto out; |
| 736 | } |
| 737 | |
| 738 | mutex_lock(&bfc->bc_mutex); |
| 739 | error = incfs_write_mapping_fh_to_backing_file(bfc, uuid, size, offset); |
| 740 | if (error) |
| 741 | goto out; |
| 742 | |
| 743 | out: |
| 744 | if (bfc) { |
| 745 | mutex_unlock(&bfc->bc_mutex); |
| 746 | incfs_free_bfc(bfc); |
| 747 | } |
| 748 | |
| 749 | if (error) |
| 750 | pr_debug("incfs: %s error: %d\n", __func__, error); |
| 751 | return error; |
| 752 | } |
| 753 | |
| 754 | static long ioctl_create_mapped_file(struct file *file, void __user *arg) |
| 755 | { |
| 756 | struct mount_info *mi = get_mount_info(file_superblock(file)); |
| 757 | struct incfs_create_mapped_file_args __user *args_usr_ptr = arg; |
| 758 | struct incfs_create_mapped_file_args args = {}; |
| 759 | char *file_name; |
| 760 | int error = 0; |
| 761 | struct path parent_dir_path = {}; |
| 762 | char *source_file_name = NULL; |
| 763 | struct dentry *source_file_dentry = NULL; |
| 764 | u64 source_file_size; |
| 765 | struct dentry *file_dentry = NULL; |
| 766 | struct inode *parent_inode; |
| 767 | __le64 size_attr_value; |
| 768 | |
| 769 | if (copy_from_user(&args, args_usr_ptr, sizeof(args)) > 0) |
| 770 | return -EINVAL; |
| 771 | |
| 772 | file_name = strndup_user(u64_to_user_ptr(args.file_name), PATH_MAX); |
| 773 | if (IS_ERR(file_name)) { |
| 774 | error = PTR_ERR(file_name); |
| 775 | file_name = NULL; |
| 776 | goto out; |
| 777 | } |
| 778 | |
| 779 | error = validate_name(file_name); |
| 780 | if (error) |
| 781 | goto out; |
| 782 | |
| 783 | if (args.source_offset % INCFS_DATA_FILE_BLOCK_SIZE) { |
| 784 | error = -EINVAL; |
| 785 | goto out; |
| 786 | } |
| 787 | |
| 788 | /* Validate file mapping is in range */ |
| 789 | source_file_name = file_id_to_str(args.source_file_id); |
| 790 | if (!source_file_name) { |
| 791 | pr_warn("Failed to alloc source_file_name\n"); |
| 792 | error = -ENOMEM; |
| 793 | goto out; |
| 794 | } |
| 795 | |
| 796 | source_file_dentry = incfs_lookup_dentry(mi->mi_index_dir, |
| 797 | source_file_name); |
| 798 | if (!source_file_dentry) { |
| 799 | pr_warn("Source file does not exist\n"); |
| 800 | error = -EINVAL; |
| 801 | goto out; |
| 802 | } |
| 803 | if (IS_ERR(source_file_dentry)) { |
| 804 | pr_warn("Error opening source file\n"); |
| 805 | error = PTR_ERR(source_file_dentry); |
| 806 | source_file_dentry = NULL; |
| 807 | goto out; |
| 808 | } |
| 809 | if (!d_really_is_positive(source_file_dentry)) { |
| 810 | pr_warn("Source file dentry negative\n"); |
| 811 | error = -EINVAL; |
| 812 | goto out; |
| 813 | } |
| 814 | |
| 815 | error = vfs_getxattr(source_file_dentry, INCFS_XATTR_SIZE_NAME, |
| 816 | (char *)&size_attr_value, sizeof(size_attr_value)); |
| 817 | if (error < 0) |
| 818 | goto out; |
| 819 | |
| 820 | if (error != sizeof(size_attr_value)) { |
| 821 | pr_warn("Mapped file has no size attr\n"); |
| 822 | error = -EINVAL; |
| 823 | goto out; |
| 824 | } |
| 825 | |
| 826 | source_file_size = le64_to_cpu(size_attr_value); |
| 827 | if (args.source_offset + args.size > source_file_size) { |
| 828 | pr_warn("Mapped file out of range\n"); |
| 829 | error = -EINVAL; |
| 830 | goto out; |
| 831 | } |
| 832 | |
| 833 | /* Find a directory to put the file into. */ |
| 834 | error = dir_relative_path_resolve(mi, |
| 835 | u64_to_user_ptr(args.directory_path), |
| 836 | &parent_dir_path, NULL); |
| 837 | if (error) |
| 838 | goto out; |
| 839 | |
| 840 | if (parent_dir_path.dentry == mi->mi_index_dir) { |
| 841 | /* Can't create a file directly inside .index */ |
| 842 | error = -EBUSY; |
| 843 | goto out; |
| 844 | } |
| 845 | |
| 846 | /* Look up a dentry in the parent dir. It should be negative. */ |
| 847 | file_dentry = incfs_lookup_dentry(parent_dir_path.dentry, |
| 848 | file_name); |
| 849 | if (!file_dentry) { |
| 850 | error = -EFAULT; |
| 851 | goto out; |
| 852 | } |
| 853 | if (IS_ERR(file_dentry)) { |
| 854 | error = PTR_ERR(file_dentry); |
| 855 | file_dentry = NULL; |
| 856 | goto out; |
| 857 | } |
| 858 | if (d_really_is_positive(file_dentry)) { |
| 859 | error = -EEXIST; |
| 860 | goto out; |
| 861 | } |
| 862 | |
| 863 | parent_inode = d_inode(parent_dir_path.dentry); |
| 864 | inode_lock_nested(parent_inode, I_MUTEX_PARENT); |
| 865 | error = vfs_create(parent_inode, file_dentry, args.mode | 0222, true); |
| 866 | inode_unlock(parent_inode); |
| 867 | if (error) |
| 868 | goto out; |
| 869 | |
| 870 | error = chmod(file_dentry, args.mode | 0222); |
| 871 | if (error) { |
| 872 | pr_debug("incfs: chmod err: %d\n", error); |
| 873 | goto delete_file; |
| 874 | } |
| 875 | |
| 876 | /* Save the file's size as an xattr for easy fetching in future. */ |
| 877 | size_attr_value = cpu_to_le64(args.size); |
| 878 | error = vfs_setxattr(file_dentry, INCFS_XATTR_SIZE_NAME, |
| 879 | (char *)&size_attr_value, sizeof(size_attr_value), |
| 880 | XATTR_CREATE); |
| 881 | if (error) { |
| 882 | pr_debug("incfs: vfs_setxattr err:%d\n", error); |
| 883 | goto delete_file; |
| 884 | } |
| 885 | |
| 886 | error = init_new_mapped_file(mi, file_dentry, &args.source_file_id, |
| 887 | args.size, args.source_offset); |
| 888 | if (error) |
| 889 | goto delete_file; |
| 890 | |
| 891 | notify_create(file, u64_to_user_ptr(args.directory_path), file_name, |
| 892 | NULL, false); |
| 893 | |
| 894 | goto out; |
| 895 | |
| 896 | delete_file: |
| 897 | incfs_unlink(file_dentry); |
| 898 | |
| 899 | out: |
| 900 | dput(file_dentry); |
| 901 | dput(source_file_dentry); |
| 902 | path_put(&parent_dir_path); |
| 903 | kfree(file_name); |
| 904 | kfree(source_file_name); |
| 905 | return error; |
| 906 | } |
| 907 | |
| 908 | static long ioctl_get_read_timeouts(struct mount_info *mi, void __user *arg) |
| 909 | { |
| 910 | struct incfs_get_read_timeouts_args __user *args_usr_ptr = arg; |
| 911 | struct incfs_get_read_timeouts_args args = {}; |
| 912 | int error = 0; |
| 913 | struct incfs_per_uid_read_timeouts *buffer; |
| 914 | int size; |
| 915 | |
| 916 | if (copy_from_user(&args, args_usr_ptr, sizeof(args))) |
| 917 | return -EINVAL; |
| 918 | |
| 919 | if (args.timeouts_array_size > INCFS_DATA_FILE_BLOCK_SIZE) |
| 920 | return -EINVAL; |
| 921 | |
| 922 | buffer = kzalloc(args.timeouts_array_size, GFP_NOFS); |
| 923 | if (!buffer) |
| 924 | return -ENOMEM; |
| 925 | |
| 926 | spin_lock(&mi->mi_per_uid_read_timeouts_lock); |
| 927 | size = mi->mi_per_uid_read_timeouts_size; |
| 928 | if (args.timeouts_array_size < size) |
| 929 | error = -E2BIG; |
| 930 | else if (size) |
| 931 | memcpy(buffer, mi->mi_per_uid_read_timeouts, size); |
| 932 | spin_unlock(&mi->mi_per_uid_read_timeouts_lock); |
| 933 | |
| 934 | args.timeouts_array_size_out = size; |
| 935 | if (!error && size) |
| 936 | if (copy_to_user(u64_to_user_ptr(args.timeouts_array), buffer, |
| 937 | size)) |
| 938 | error = -EFAULT; |
| 939 | |
| 940 | if (!error || error == -E2BIG) |
| 941 | if (copy_to_user(args_usr_ptr, &args, sizeof(args)) > 0) |
| 942 | error = -EFAULT; |
| 943 | |
| 944 | kfree(buffer); |
| 945 | return error; |
| 946 | } |
| 947 | |
| 948 | static long ioctl_set_read_timeouts(struct mount_info *mi, void __user *arg) |
| 949 | { |
| 950 | struct incfs_set_read_timeouts_args __user *args_usr_ptr = arg; |
| 951 | struct incfs_set_read_timeouts_args args = {}; |
| 952 | int error = 0; |
| 953 | int size; |
| 954 | struct incfs_per_uid_read_timeouts *buffer = NULL, *tmp; |
| 955 | int i; |
| 956 | |
| 957 | if (copy_from_user(&args, args_usr_ptr, sizeof(args))) |
| 958 | return -EINVAL; |
| 959 | |
| 960 | size = args.timeouts_array_size; |
| 961 | if (size) { |
| 962 | if (size > INCFS_DATA_FILE_BLOCK_SIZE || |
| 963 | size % sizeof(*buffer) != 0) |
| 964 | return -EINVAL; |
| 965 | |
| 966 | buffer = kzalloc(size, GFP_NOFS); |
| 967 | if (!buffer) |
| 968 | return -ENOMEM; |
| 969 | |
| 970 | if (copy_from_user(buffer, u64_to_user_ptr(args.timeouts_array), |
| 971 | size)) { |
| 972 | error = -EINVAL; |
| 973 | goto out; |
| 974 | } |
| 975 | |
| 976 | for (i = 0; i < size / sizeof(*buffer); ++i) { |
| 977 | struct incfs_per_uid_read_timeouts *t = &buffer[i]; |
| 978 | |
| 979 | if (t->min_pending_time_us > t->max_pending_time_us) { |
| 980 | error = -EINVAL; |
| 981 | goto out; |
| 982 | } |
| 983 | } |
| 984 | } |
| 985 | |
| 986 | spin_lock(&mi->mi_per_uid_read_timeouts_lock); |
| 987 | mi->mi_per_uid_read_timeouts_size = size; |
| 988 | tmp = mi->mi_per_uid_read_timeouts; |
| 989 | mi->mi_per_uid_read_timeouts = buffer; |
| 990 | buffer = tmp; |
| 991 | spin_unlock(&mi->mi_per_uid_read_timeouts_lock); |
| 992 | |
| 993 | out: |
| 994 | kfree(buffer); |
| 995 | return error; |
| 996 | } |
| 997 | |
| 998 | static long ioctl_get_last_read_error(struct mount_info *mi, void __user *arg) |
| 999 | { |
| 1000 | struct incfs_get_last_read_error_args __user *args_usr_ptr = arg; |
| 1001 | struct incfs_get_last_read_error_args args = {}; |
| 1002 | int error; |
| 1003 | |
| 1004 | error = mutex_lock_interruptible(&mi->mi_le_mutex); |
| 1005 | if (error) |
| 1006 | return error; |
| 1007 | |
| 1008 | args.file_id_out = mi->mi_le_file_id; |
| 1009 | args.time_us_out = mi->mi_le_time_us; |
| 1010 | args.page_out = mi->mi_le_page; |
| 1011 | args.errno_out = mi->mi_le_errno; |
| 1012 | args.uid_out = mi->mi_le_uid; |
| 1013 | |
| 1014 | mutex_unlock(&mi->mi_le_mutex); |
| 1015 | if (copy_to_user(args_usr_ptr, &args, sizeof(args)) > 0) |
| 1016 | error = -EFAULT; |
| 1017 | |
| 1018 | return error; |
| 1019 | } |
| 1020 | |
| 1021 | static long pending_reads_dispatch_ioctl(struct file *f, unsigned int req, |
| 1022 | unsigned long arg) |
| 1023 | { |
| 1024 | struct mount_info *mi = get_mount_info(file_superblock(f)); |
| 1025 | |
| 1026 | switch (req) { |
| 1027 | case INCFS_IOC_CREATE_FILE: |
| 1028 | return ioctl_create_file(f, (void __user *)arg); |
| 1029 | case INCFS_IOC_PERMIT_FILL: |
| 1030 | return ioctl_permit_fill(f, (void __user *)arg); |
| 1031 | case INCFS_IOC_CREATE_MAPPED_FILE: |
| 1032 | return ioctl_create_mapped_file(f, (void __user *)arg); |
| 1033 | case INCFS_IOC_GET_READ_TIMEOUTS: |
| 1034 | return ioctl_get_read_timeouts(mi, (void __user *)arg); |
| 1035 | case INCFS_IOC_SET_READ_TIMEOUTS: |
| 1036 | return ioctl_set_read_timeouts(mi, (void __user *)arg); |
| 1037 | case INCFS_IOC_GET_LAST_READ_ERROR: |
| 1038 | return ioctl_get_last_read_error(mi, (void __user *)arg); |
| 1039 | default: |
| 1040 | return -EINVAL; |
| 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | static const struct file_operations incfs_pending_reads_file_ops = { |
| 1045 | .read = pending_reads_read, |
| 1046 | .poll = pending_reads_poll, |
| 1047 | .open = pending_reads_open, |
| 1048 | .release = pending_reads_release, |
| 1049 | .llseek = noop_llseek, |
| 1050 | .unlocked_ioctl = pending_reads_dispatch_ioctl, |
| 1051 | .compat_ioctl = pending_reads_dispatch_ioctl |
| 1052 | }; |
| 1053 | |
| 1054 | /******************************************************************************* |
| 1055 | * .log pseudo file definition |
| 1056 | ******************************************************************************/ |
| 1057 | #define INCFS_LOG_INODE 3 |
| 1058 | static const char log_file_name[] = INCFS_LOG_FILENAME; |
| 1059 | |
| 1060 | /* State of an open .log file, unique for each file descriptor. */ |
| 1061 | struct log_file_state { |
| 1062 | struct read_log_state state; |
| 1063 | }; |
| 1064 | |
| 1065 | static ssize_t log_read(struct file *f, char __user *buf, size_t len, |
| 1066 | loff_t *ppos) |
| 1067 | { |
| 1068 | struct log_file_state *log_state = f->private_data; |
| 1069 | struct mount_info *mi = get_mount_info(file_superblock(f)); |
| 1070 | int total_reads_collected = 0; |
| 1071 | int rl_size; |
| 1072 | ssize_t result = 0; |
| 1073 | bool report_uid; |
| 1074 | unsigned long page = 0; |
| 1075 | struct incfs_pending_read_info *reads_buf = NULL; |
| 1076 | struct incfs_pending_read_info2 *reads_buf2 = NULL; |
| 1077 | size_t record_size; |
| 1078 | ssize_t reads_to_collect; |
| 1079 | ssize_t reads_per_page; |
| 1080 | |
| 1081 | if (!mi) |
| 1082 | return -EFAULT; |
| 1083 | |
| 1084 | report_uid = mi->mi_options.report_uid; |
| 1085 | record_size = report_uid ? sizeof(*reads_buf2) : sizeof(*reads_buf); |
| 1086 | reads_to_collect = len / record_size; |
| 1087 | reads_per_page = PAGE_SIZE / record_size; |
| 1088 | |
| 1089 | rl_size = READ_ONCE(mi->mi_log.rl_size); |
| 1090 | if (rl_size == 0) |
| 1091 | return 0; |
| 1092 | |
| 1093 | page = __get_free_page(GFP_NOFS); |
| 1094 | if (!page) |
| 1095 | return -ENOMEM; |
| 1096 | |
| 1097 | if (report_uid) |
| 1098 | reads_buf2 = (struct incfs_pending_read_info2 *)page; |
| 1099 | else |
| 1100 | reads_buf = (struct incfs_pending_read_info *)page; |
| 1101 | |
| 1102 | reads_to_collect = min_t(ssize_t, rl_size, reads_to_collect); |
| 1103 | while (reads_to_collect > 0) { |
| 1104 | struct read_log_state next_state; |
| 1105 | int reads_collected; |
| 1106 | |
| 1107 | memcpy(&next_state, &log_state->state, sizeof(next_state)); |
| 1108 | reads_collected = incfs_collect_logged_reads( |
| 1109 | mi, &next_state, reads_buf, reads_buf2, |
| 1110 | min_t(ssize_t, reads_to_collect, reads_per_page)); |
| 1111 | if (reads_collected <= 0) { |
| 1112 | result = total_reads_collected ? |
| 1113 | total_reads_collected * record_size : |
| 1114 | reads_collected; |
| 1115 | goto out; |
| 1116 | } |
| 1117 | if (copy_to_user(buf, (void *)page, |
| 1118 | reads_collected * record_size)) { |
| 1119 | result = total_reads_collected ? |
| 1120 | total_reads_collected * record_size : |
| 1121 | -EFAULT; |
| 1122 | goto out; |
| 1123 | } |
| 1124 | |
| 1125 | memcpy(&log_state->state, &next_state, sizeof(next_state)); |
| 1126 | total_reads_collected += reads_collected; |
| 1127 | buf += reads_collected * record_size; |
| 1128 | reads_to_collect -= reads_collected; |
| 1129 | } |
| 1130 | |
| 1131 | result = total_reads_collected * record_size; |
| 1132 | *ppos = 0; |
| 1133 | out: |
| 1134 | free_page(page); |
| 1135 | return result; |
| 1136 | } |
| 1137 | |
| 1138 | static __poll_t log_poll(struct file *file, poll_table *wait) |
| 1139 | { |
| 1140 | struct log_file_state *log_state = file->private_data; |
| 1141 | struct mount_info *mi = get_mount_info(file_superblock(file)); |
| 1142 | int count; |
| 1143 | __poll_t ret = 0; |
| 1144 | |
| 1145 | poll_wait(file, &mi->mi_log.ml_notif_wq, wait); |
| 1146 | count = incfs_get_uncollected_logs_count(mi, &log_state->state); |
| 1147 | if (count >= mi->mi_options.read_log_wakeup_count) |
| 1148 | ret = EPOLLIN | EPOLLRDNORM; |
| 1149 | |
| 1150 | return ret; |
| 1151 | } |
| 1152 | |
| 1153 | static int log_open(struct inode *inode, struct file *file) |
| 1154 | { |
| 1155 | struct log_file_state *log_state = NULL; |
| 1156 | struct mount_info *mi = get_mount_info(file_superblock(file)); |
| 1157 | |
| 1158 | log_state = kzalloc(sizeof(*log_state), GFP_NOFS); |
| 1159 | if (!log_state) |
| 1160 | return -ENOMEM; |
| 1161 | |
| 1162 | log_state->state = incfs_get_log_state(mi); |
| 1163 | file->private_data = log_state; |
| 1164 | return 0; |
| 1165 | } |
| 1166 | |
| 1167 | static int log_release(struct inode *inode, struct file *file) |
| 1168 | { |
| 1169 | kfree(file->private_data); |
| 1170 | return 0; |
| 1171 | } |
| 1172 | |
| 1173 | static const struct file_operations incfs_log_file_ops = { |
| 1174 | .read = log_read, |
| 1175 | .poll = log_poll, |
| 1176 | .open = log_open, |
| 1177 | .release = log_release, |
| 1178 | .llseek = noop_llseek, |
| 1179 | }; |
| 1180 | |
| 1181 | /******************************************************************************* |
| 1182 | * .blocks_written pseudo file definition |
| 1183 | ******************************************************************************/ |
| 1184 | #define INCFS_BLOCKS_WRITTEN_INODE 4 |
| 1185 | static const char blocks_written_file_name[] = INCFS_BLOCKS_WRITTEN_FILENAME; |
| 1186 | |
| 1187 | /* State of an open .blocks_written file, unique for each file descriptor. */ |
| 1188 | struct blocks_written_file_state { |
| 1189 | unsigned long blocks_written; |
| 1190 | }; |
| 1191 | |
| 1192 | static ssize_t blocks_written_read(struct file *f, char __user *buf, size_t len, |
| 1193 | loff_t *ppos) |
| 1194 | { |
| 1195 | struct mount_info *mi = get_mount_info(file_superblock(f)); |
| 1196 | struct blocks_written_file_state *state = f->private_data; |
| 1197 | unsigned long blocks_written; |
| 1198 | char string[21]; |
| 1199 | int result = 0; |
| 1200 | |
| 1201 | if (!mi) |
| 1202 | return -EFAULT; |
| 1203 | |
| 1204 | blocks_written = atomic_read(&mi->mi_blocks_written); |
| 1205 | if (state->blocks_written == blocks_written) |
| 1206 | return 0; |
| 1207 | |
| 1208 | result = snprintf(string, sizeof(string), "%lu", blocks_written); |
| 1209 | if (result > len) |
| 1210 | result = len; |
| 1211 | if (copy_to_user(buf, string, result)) |
| 1212 | return -EFAULT; |
| 1213 | |
| 1214 | state->blocks_written = blocks_written; |
| 1215 | return result; |
| 1216 | } |
| 1217 | |
| 1218 | static __poll_t blocks_written_poll(struct file *f, poll_table *wait) |
| 1219 | { |
| 1220 | struct mount_info *mi = get_mount_info(file_superblock(f)); |
| 1221 | struct blocks_written_file_state *state = f->private_data; |
| 1222 | unsigned long blocks_written; |
| 1223 | |
| 1224 | if (!mi) |
| 1225 | return 0; |
| 1226 | |
| 1227 | poll_wait(f, &mi->mi_blocks_written_notif_wq, wait); |
| 1228 | blocks_written = atomic_read(&mi->mi_blocks_written); |
| 1229 | if (state->blocks_written == blocks_written) |
| 1230 | return 0; |
| 1231 | |
| 1232 | return EPOLLIN | EPOLLRDNORM; |
| 1233 | } |
| 1234 | |
| 1235 | static int blocks_written_open(struct inode *inode, struct file *file) |
| 1236 | { |
| 1237 | struct blocks_written_file_state *state = |
| 1238 | kzalloc(sizeof(*state), GFP_NOFS); |
| 1239 | |
| 1240 | if (!state) |
| 1241 | return -ENOMEM; |
| 1242 | |
| 1243 | state->blocks_written = -1; |
| 1244 | file->private_data = state; |
| 1245 | return 0; |
| 1246 | } |
| 1247 | |
| 1248 | static int blocks_written_release(struct inode *inode, struct file *file) |
| 1249 | { |
| 1250 | kfree(file->private_data); |
| 1251 | return 0; |
| 1252 | } |
| 1253 | |
| 1254 | static const struct file_operations incfs_blocks_written_file_ops = { |
| 1255 | .read = blocks_written_read, |
| 1256 | .poll = blocks_written_poll, |
| 1257 | .open = blocks_written_open, |
| 1258 | .release = blocks_written_release, |
| 1259 | .llseek = noop_llseek, |
| 1260 | }; |
| 1261 | |
| 1262 | /******************************************************************************* |
| 1263 | * Generic inode lookup functionality |
| 1264 | ******************************************************************************/ |
| 1265 | |
| 1266 | const struct mem_range incfs_pseudo_file_names[] = { |
| 1267 | { .data = (u8 *)pending_reads_file_name, |
| 1268 | .len = ARRAY_SIZE(pending_reads_file_name) - 1 }, |
| 1269 | { .data = (u8 *)log_file_name, .len = ARRAY_SIZE(log_file_name) - 1 }, |
| 1270 | { .data = (u8 *)blocks_written_file_name, |
| 1271 | .len = ARRAY_SIZE(blocks_written_file_name) - 1 } |
| 1272 | }; |
| 1273 | |
| 1274 | const unsigned long incfs_pseudo_file_inodes[] = { INCFS_PENDING_READS_INODE, |
| 1275 | INCFS_LOG_INODE, |
| 1276 | INCFS_BLOCKS_WRITTEN_INODE }; |
| 1277 | |
| 1278 | static const struct file_operations *const pseudo_file_operations[] = { |
| 1279 | &incfs_pending_reads_file_ops, &incfs_log_file_ops, |
| 1280 | &incfs_blocks_written_file_ops |
| 1281 | }; |
| 1282 | |
| 1283 | static bool is_pseudo_filename(struct mem_range name) |
| 1284 | { |
| 1285 | int i = 0; |
| 1286 | |
| 1287 | for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i) |
| 1288 | if (incfs_equal_ranges(incfs_pseudo_file_names[i], name)) |
| 1289 | return true; |
| 1290 | return false; |
| 1291 | } |
| 1292 | |
| 1293 | static bool get_pseudo_inode(int ino, struct inode *inode) |
| 1294 | { |
| 1295 | int i = 0; |
| 1296 | |
| 1297 | for (; i < ARRAY_SIZE(incfs_pseudo_file_inodes); ++i) |
| 1298 | if (ino == incfs_pseudo_file_inodes[i]) |
| 1299 | break; |
| 1300 | if (i == ARRAY_SIZE(incfs_pseudo_file_inodes)) |
| 1301 | return false; |
| 1302 | |
| 1303 | inode->i_ctime = (struct timespec64){}; |
| 1304 | inode->i_mtime = inode->i_ctime; |
| 1305 | inode->i_atime = inode->i_ctime; |
| 1306 | inode->i_size = 0; |
| 1307 | inode->i_ino = ino; |
| 1308 | inode->i_private = NULL; |
| 1309 | inode_init_owner(inode, NULL, S_IFREG | READ_WRITE_FILE_MODE); |
| 1310 | inode->i_op = &incfs_file_inode_ops; |
| 1311 | inode->i_fop = pseudo_file_operations[i]; |
| 1312 | return true; |
| 1313 | } |
| 1314 | |
| 1315 | struct inode_search { |
| 1316 | unsigned long ino; |
| 1317 | }; |
| 1318 | |
| 1319 | static int inode_test(struct inode *inode, void *opaque) |
| 1320 | { |
| 1321 | struct inode_search *search = opaque; |
| 1322 | |
| 1323 | return inode->i_ino == search->ino; |
| 1324 | } |
| 1325 | |
| 1326 | static int inode_set(struct inode *inode, void *opaque) |
| 1327 | { |
| 1328 | struct inode_search *search = opaque; |
| 1329 | |
| 1330 | if (get_pseudo_inode(search->ino, inode)) |
| 1331 | return 0; |
| 1332 | |
| 1333 | /* Unknown inode requested. */ |
| 1334 | return -EINVAL; |
| 1335 | } |
| 1336 | |
| 1337 | static struct inode *fetch_inode(struct super_block *sb, unsigned long ino) |
| 1338 | { |
| 1339 | struct inode_search search = { |
| 1340 | .ino = ino |
| 1341 | }; |
| 1342 | struct inode *inode = iget5_locked(sb, search.ino, inode_test, |
| 1343 | inode_set, &search); |
| 1344 | |
| 1345 | if (!inode) |
| 1346 | return ERR_PTR(-ENOMEM); |
| 1347 | |
| 1348 | if (inode->i_state & I_NEW) |
| 1349 | unlock_new_inode(inode); |
| 1350 | |
| 1351 | return inode; |
| 1352 | } |
| 1353 | |
| 1354 | int dir_lookup_pseudo_files(struct super_block *sb, struct dentry *dentry) |
| 1355 | { |
| 1356 | struct mem_range name_range = |
| 1357 | range((u8 *)dentry->d_name.name, dentry->d_name.len); |
| 1358 | unsigned long ino; |
| 1359 | struct inode *inode; |
| 1360 | int i = 0; |
| 1361 | |
| 1362 | for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i) |
| 1363 | if (incfs_equal_ranges(incfs_pseudo_file_names[i], name_range)) |
| 1364 | break; |
| 1365 | if (i == ARRAY_SIZE(incfs_pseudo_file_names)) |
| 1366 | return -ENOENT; |
| 1367 | |
| 1368 | ino = incfs_pseudo_file_inodes[i]; |
| 1369 | |
| 1370 | inode = fetch_inode(sb, ino); |
| 1371 | if (IS_ERR(inode)) |
| 1372 | return PTR_ERR(inode); |
| 1373 | |
| 1374 | d_add(dentry, inode); |
| 1375 | return 0; |
| 1376 | } |
| 1377 | |
| 1378 | int emit_pseudo_files(struct dir_context *ctx) |
| 1379 | { |
| 1380 | loff_t i = ctx->pos; |
| 1381 | |
| 1382 | for (; i < ARRAY_SIZE(incfs_pseudo_file_names); ++i) { |
| 1383 | if (!dir_emit(ctx, incfs_pseudo_file_names[i].data, |
| 1384 | incfs_pseudo_file_names[i].len, |
| 1385 | incfs_pseudo_file_inodes[i], DT_REG)) |
| 1386 | return -EINVAL; |
| 1387 | |
| 1388 | ctx->pos++; |
| 1389 | } |
| 1390 | return 0; |
| 1391 | } |