1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implementation of the diskquota system for the LINUX operating system. QUOTA 4 * is implemented using the BSD system call interface as the means of 5 * communication with the user level. This file contains the generic routines 6 * called by the different filesystems on allocation of an inode or block. 7 * These routines take care of the administration needed to have a consistent 8 * diskquota tracking system. The ideas of both user and group quotas are based 9 * on the Melbourne quota system as used on BSD derived systems. The internal 10 * implementation is based on one of the several variants of the LINUX 11 * inode-subsystem with added complexity of the diskquota system. 12 * 13 * Author: Marco van Wieringen <mvw@planets.elm.net> 14 * 15 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 16 * 17 * Revised list management to avoid races 18 * -- Bill Hawes, <whawes@star.net>, 9/98 19 * 20 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). 21 * As the consequence the locking was moved from dquot_decr_...(), 22 * dquot_incr_...() to calling functions. 23 * invalidate_dquots() now writes modified dquots. 24 * Serialized quota_off() and quota_on() for mount point. 25 * Fixed a few bugs in grow_dquots(). 26 * Fixed deadlock in write_dquot() - we no longer account quotas on 27 * quota files 28 * remove_dquot_ref() moved to inode.c - it now traverses through inodes 29 * add_dquot_ref() restarts after blocking 30 * Added check for bogus uid and fixed check for group in quotactl. 31 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99 32 * 33 * Used struct list_head instead of own list struct 34 * Invalidation of referenced dquots is no longer possible 35 * Improved free_dquots list management 36 * Quota and i_blocks are now updated in one place to avoid races 37 * Warnings are now delayed so we won't block in critical section 38 * Write updated not to require dquot lock 39 * Jan Kara, <jack@suse.cz>, 9/2000 40 * 41 * Added dynamic quota structure allocation 42 * Jan Kara <jack@suse.cz> 12/2000 43 * 44 * Rewritten quota interface. Implemented new quota format and 45 * formats registering. 46 * Jan Kara, <jack@suse.cz>, 2001,2002 47 * 48 * New SMP locking. 49 * Jan Kara, <jack@suse.cz>, 10/2002 50 * 51 * Added journalled quota support, fix lock inversion problems 52 * Jan Kara, <jack@suse.cz>, 2003,2004 53 * 54 * (C) Copyright 1994 - 1997 Marco van Wieringen 55 */ 56 57 #include <linux/errno.h> 58 #include <linux/kernel.h> 59 #include <linux/fs.h> 60 #include <linux/mount.h> 61 #include <linux/mm.h> 62 #include <linux/time.h> 63 #include <linux/types.h> 64 #include <linux/string.h> 65 #include <linux/fcntl.h> 66 #include <linux/stat.h> 67 #include <linux/tty.h> 68 #include <linux/file.h> 69 #include <linux/slab.h> 70 #include <linux/sysctl.h> 71 #include <linux/init.h> 72 #include <linux/module.h> 73 #include <linux/proc_fs.h> 74 #include <linux/security.h> 75 #include <linux/sched.h> 76 #include <linux/cred.h> 77 #include <linux/kmod.h> 78 #include <linux/namei.h> 79 #include <linux/capability.h> 80 #include <linux/quotaops.h> 81 #include "../internal.h" /* ugh */ 82 83 #include <linux/uaccess.h> 84 85 /* 86 * There are five quota SMP locks: 87 * * dq_list_lock protects all lists with quotas and quota formats. 88 * * dquot->dq_dqb_lock protects data from dq_dqb 89 * * inode->i_lock protects inode->i_blocks, i_bytes and also guards 90 * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that 91 * dquot_transfer() can stabilize amount it transfers 92 * * dq_data_lock protects mem_dqinfo structures and modifications of dquot 93 * pointers in the inode 94 * * dq_state_lock protects modifications of quota state (on quotaon and 95 * quotaoff) and readers who care about latest values take it as well. 96 * 97 * The spinlock ordering is hence: 98 * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, 99 * dq_list_lock > dq_state_lock 100 * 101 * Note that some things (eg. sb pointer, type, id) doesn't change during 102 * the life of the dquot structure and so needn't to be protected by a lock 103 * 104 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 105 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 106 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 107 * inode and before dropping dquot references to avoid use of dquots after 108 * they are freed. dq_data_lock is used to serialize the pointer setting and 109 * clearing operations. 110 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 111 * inode is a quota file). Functions adding pointers from inode to dquots have 112 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 113 * have to do all pointer modifications before dropping dq_data_lock. This makes 114 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 115 * then drops all pointers to dquots from an inode. 116 * 117 * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to 118 * memory (or space for it is being allocated) on the first dqget(), when it is 119 * being written out, and when it is being released on the last dqput(). The 120 * allocation and release operations are serialized by the dq_lock and by 121 * checking the use count in dquot_release(). 122 * 123 * Lock ordering (including related VFS locks) is the following: 124 * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem 125 */ 126 127 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 128 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 129 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 130 EXPORT_SYMBOL(dq_data_lock); 131 DEFINE_STATIC_SRCU(dquot_srcu); 132 133 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); 134 135 void __quota_error(struct super_block *sb, const char *func, 136 const char *fmt, ...) 137 { 138 if (printk_ratelimit()) { 139 va_list args; 140 struct va_format vaf; 141 142 va_start(args, fmt); 143 144 vaf.fmt = fmt; 145 vaf.va = &args; 146 147 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 148 sb->s_id, func, &vaf); 149 150 va_end(args); 151 } 152 } 153 EXPORT_SYMBOL(__quota_error); 154 155 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 156 static char *quotatypes[] = INITQFNAMES; 157 #endif 158 static struct quota_format_type *quota_formats; /* List of registered formats */ 159 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 160 161 /* SLAB cache for dquot structures */ 162 static struct kmem_cache *dquot_cachep; 163 164 int register_quota_format(struct quota_format_type *fmt) 165 { 166 spin_lock(&dq_list_lock); 167 fmt->qf_next = quota_formats; 168 quota_formats = fmt; 169 spin_unlock(&dq_list_lock); 170 return 0; 171 } 172 EXPORT_SYMBOL(register_quota_format); 173 174 void unregister_quota_format(struct quota_format_type *fmt) 175 { 176 struct quota_format_type **actqf; 177 178 spin_lock(&dq_list_lock); 179 for (actqf = "a_formats; *actqf && *actqf != fmt; 180 actqf = &(*actqf)->qf_next) 181 ; 182 if (*actqf) 183 *actqf = (*actqf)->qf_next; 184 spin_unlock(&dq_list_lock); 185 } 186 EXPORT_SYMBOL(unregister_quota_format); 187 188 static struct quota_format_type *find_quota_format(int id) 189 { 190 struct quota_format_type *actqf; 191 192 spin_lock(&dq_list_lock); 193 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 194 actqf = actqf->qf_next) 195 ; 196 if (!actqf || !try_module_get(actqf->qf_owner)) { 197 int qm; 198 199 spin_unlock(&dq_list_lock); 200 201 for (qm = 0; module_names[qm].qm_fmt_id && 202 module_names[qm].qm_fmt_id != id; qm++) 203 ; 204 if (!module_names[qm].qm_fmt_id || 205 request_module(module_names[qm].qm_mod_name)) 206 return NULL; 207 208 spin_lock(&dq_list_lock); 209 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 210 actqf = actqf->qf_next) 211 ; 212 if (actqf && !try_module_get(actqf->qf_owner)) 213 actqf = NULL; 214 } 215 spin_unlock(&dq_list_lock); 216 return actqf; 217 } 218 219 static void put_quota_format(struct quota_format_type *fmt) 220 { 221 module_put(fmt->qf_owner); 222 } 223 224 /* 225 * Dquot List Management: 226 * The quota code uses three lists for dquot management: the inuse_list, 227 * free_dquots, and dquot_hash[] array. A single dquot structure may be 228 * on all three lists, depending on its current state. 229 * 230 * All dquots are placed to the end of inuse_list when first created, and this 231 * list is used for invalidate operation, which must look at every dquot. 232 * 233 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 234 * and this list is searched whenever we need an available dquot. Dquots are 235 * removed from the list as soon as they are used again, and 236 * dqstats.free_dquots gives the number of dquots on the list. When 237 * dquot is invalidated it's completely released from memory. 238 * 239 * Dquots with a specific identity (device, type and id) are placed on 240 * one of the dquot_hash[] hash chains. The provides an efficient search 241 * mechanism to locate a specific dquot. 242 */ 243 244 static LIST_HEAD(inuse_list); 245 static LIST_HEAD(free_dquots); 246 static unsigned int dq_hash_bits, dq_hash_mask; 247 static struct hlist_head *dquot_hash; 248 249 struct dqstats dqstats; 250 EXPORT_SYMBOL(dqstats); 251 252 static qsize_t inode_get_rsv_space(struct inode *inode); 253 static qsize_t __inode_get_rsv_space(struct inode *inode); 254 static int __dquot_initialize(struct inode *inode, int type); 255 256 static inline unsigned int 257 hashfn(const struct super_block *sb, struct kqid qid) 258 { 259 unsigned int id = from_kqid(&init_user_ns, qid); 260 int type = qid.type; 261 unsigned long tmp; 262 263 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 264 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 265 } 266 267 /* 268 * Following list functions expect dq_list_lock to be held 269 */ 270 static inline void insert_dquot_hash(struct dquot *dquot) 271 { 272 struct hlist_head *head; 273 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 274 hlist_add_head(&dquot->dq_hash, head); 275 } 276 277 static inline void remove_dquot_hash(struct dquot *dquot) 278 { 279 hlist_del_init(&dquot->dq_hash); 280 } 281 282 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 283 struct kqid qid) 284 { 285 struct hlist_node *node; 286 struct dquot *dquot; 287 288 hlist_for_each (node, dquot_hash+hashent) { 289 dquot = hlist_entry(node, struct dquot, dq_hash); 290 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 291 return dquot; 292 } 293 return NULL; 294 } 295 296 /* Add a dquot to the tail of the free list */ 297 static inline void put_dquot_last(struct dquot *dquot) 298 { 299 list_add_tail(&dquot->dq_free, &free_dquots); 300 dqstats_inc(DQST_FREE_DQUOTS); 301 } 302 303 static inline void remove_free_dquot(struct dquot *dquot) 304 { 305 if (list_empty(&dquot->dq_free)) 306 return; 307 list_del_init(&dquot->dq_free); 308 dqstats_dec(DQST_FREE_DQUOTS); 309 } 310 311 static inline void put_inuse(struct dquot *dquot) 312 { 313 /* We add to the back of inuse list so we don't have to restart 314 * when traversing this list and we block */ 315 list_add_tail(&dquot->dq_inuse, &inuse_list); 316 dqstats_inc(DQST_ALLOC_DQUOTS); 317 } 318 319 static inline void remove_inuse(struct dquot *dquot) 320 { 321 dqstats_dec(DQST_ALLOC_DQUOTS); 322 list_del(&dquot->dq_inuse); 323 } 324 /* 325 * End of list functions needing dq_list_lock 326 */ 327 328 static void wait_on_dquot(struct dquot *dquot) 329 { 330 mutex_lock(&dquot->dq_lock); 331 mutex_unlock(&dquot->dq_lock); 332 } 333 334 static inline int dquot_dirty(struct dquot *dquot) 335 { 336 return test_bit(DQ_MOD_B, &dquot->dq_flags); 337 } 338 339 static inline int mark_dquot_dirty(struct dquot *dquot) 340 { 341 return dquot->dq_sb->dq_op->mark_dirty(dquot); 342 } 343 344 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 345 int dquot_mark_dquot_dirty(struct dquot *dquot) 346 { 347 int ret = 1; 348 349 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 350 return 0; 351 352 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 353 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 354 355 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 356 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 357 return 1; 358 359 spin_lock(&dq_list_lock); 360 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 361 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 362 info[dquot->dq_id.type].dqi_dirty_list); 363 ret = 0; 364 } 365 spin_unlock(&dq_list_lock); 366 return ret; 367 } 368 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 369 370 /* Dirtify all the dquots - this can block when journalling */ 371 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 372 { 373 int ret, err, cnt; 374 375 ret = err = 0; 376 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 377 if (dquot[cnt]) 378 /* Even in case of error we have to continue */ 379 ret = mark_dquot_dirty(dquot[cnt]); 380 if (!err) 381 err = ret; 382 } 383 return err; 384 } 385 386 static inline void dqput_all(struct dquot **dquot) 387 { 388 unsigned int cnt; 389 390 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 391 dqput(dquot[cnt]); 392 } 393 394 static inline int clear_dquot_dirty(struct dquot *dquot) 395 { 396 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 397 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 398 399 spin_lock(&dq_list_lock); 400 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 401 spin_unlock(&dq_list_lock); 402 return 0; 403 } 404 list_del_init(&dquot->dq_dirty); 405 spin_unlock(&dq_list_lock); 406 return 1; 407 } 408 409 void mark_info_dirty(struct super_block *sb, int type) 410 { 411 spin_lock(&dq_data_lock); 412 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 413 spin_unlock(&dq_data_lock); 414 } 415 EXPORT_SYMBOL(mark_info_dirty); 416 417 /* 418 * Read dquot from disk and alloc space for it 419 */ 420 421 int dquot_acquire(struct dquot *dquot) 422 { 423 int ret = 0, ret2 = 0; 424 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 425 426 mutex_lock(&dquot->dq_lock); 427 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 428 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 429 if (ret < 0) 430 goto out_iolock; 431 /* Make sure flags update is visible after dquot has been filled */ 432 smp_mb__before_atomic(); 433 set_bit(DQ_READ_B, &dquot->dq_flags); 434 /* Instantiate dquot if needed */ 435 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 436 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 437 /* Write the info if needed */ 438 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 439 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 440 dquot->dq_sb, dquot->dq_id.type); 441 } 442 if (ret < 0) 443 goto out_iolock; 444 if (ret2 < 0) { 445 ret = ret2; 446 goto out_iolock; 447 } 448 } 449 /* 450 * Make sure flags update is visible after on-disk struct has been 451 * allocated. Paired with smp_rmb() in dqget(). 452 */ 453 smp_mb__before_atomic(); 454 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 455 out_iolock: 456 mutex_unlock(&dquot->dq_lock); 457 return ret; 458 } 459 EXPORT_SYMBOL(dquot_acquire); 460 461 /* 462 * Write dquot to disk 463 */ 464 int dquot_commit(struct dquot *dquot) 465 { 466 int ret = 0; 467 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 468 469 mutex_lock(&dquot->dq_lock); 470 if (!clear_dquot_dirty(dquot)) 471 goto out_lock; 472 /* Inactive dquot can be only if there was error during read/init 473 * => we have better not writing it */ 474 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 475 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 476 else 477 ret = -EIO; 478 out_lock: 479 mutex_unlock(&dquot->dq_lock); 480 return ret; 481 } 482 EXPORT_SYMBOL(dquot_commit); 483 484 /* 485 * Release dquot 486 */ 487 int dquot_release(struct dquot *dquot) 488 { 489 int ret = 0, ret2 = 0; 490 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 491 492 mutex_lock(&dquot->dq_lock); 493 /* Check whether we are not racing with some other dqget() */ 494 if (atomic_read(&dquot->dq_count) > 1) 495 goto out_dqlock; 496 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 497 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 498 /* Write the info */ 499 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 500 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 501 dquot->dq_sb, dquot->dq_id.type); 502 } 503 if (ret >= 0) 504 ret = ret2; 505 } 506 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 507 out_dqlock: 508 mutex_unlock(&dquot->dq_lock); 509 return ret; 510 } 511 EXPORT_SYMBOL(dquot_release); 512 513 void dquot_destroy(struct dquot *dquot) 514 { 515 kmem_cache_free(dquot_cachep, dquot); 516 } 517 EXPORT_SYMBOL(dquot_destroy); 518 519 static inline void do_destroy_dquot(struct dquot *dquot) 520 { 521 dquot->dq_sb->dq_op->destroy_dquot(dquot); 522 } 523 524 /* Invalidate all dquots on the list. Note that this function is called after 525 * quota is disabled and pointers from inodes removed so there cannot be new 526 * quota users. There can still be some users of quotas due to inodes being 527 * just deleted or pruned by prune_icache() (those are not attached to any 528 * list) or parallel quotactl call. We have to wait for such users. 529 */ 530 static void invalidate_dquots(struct super_block *sb, int type) 531 { 532 struct dquot *dquot, *tmp; 533 534 restart: 535 spin_lock(&dq_list_lock); 536 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 537 if (dquot->dq_sb != sb) 538 continue; 539 if (dquot->dq_id.type != type) 540 continue; 541 /* Wait for dquot users */ 542 if (atomic_read(&dquot->dq_count)) { 543 dqgrab(dquot); 544 spin_unlock(&dq_list_lock); 545 /* 546 * Once dqput() wakes us up, we know it's time to free 547 * the dquot. 548 * IMPORTANT: we rely on the fact that there is always 549 * at most one process waiting for dquot to free. 550 * Otherwise dq_count would be > 1 and we would never 551 * wake up. 552 */ 553 wait_event(dquot_ref_wq, 554 atomic_read(&dquot->dq_count) == 1); 555 dqput(dquot); 556 /* At this moment dquot() need not exist (it could be 557 * reclaimed by prune_dqcache(). Hence we must 558 * restart. */ 559 goto restart; 560 } 561 /* 562 * Quota now has no users and it has been written on last 563 * dqput() 564 */ 565 remove_dquot_hash(dquot); 566 remove_free_dquot(dquot); 567 remove_inuse(dquot); 568 do_destroy_dquot(dquot); 569 } 570 spin_unlock(&dq_list_lock); 571 } 572 573 /* Call callback for every active dquot on given filesystem */ 574 int dquot_scan_active(struct super_block *sb, 575 int (*fn)(struct dquot *dquot, unsigned long priv), 576 unsigned long priv) 577 { 578 struct dquot *dquot, *old_dquot = NULL; 579 int ret = 0; 580 581 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 582 583 spin_lock(&dq_list_lock); 584 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 585 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 586 continue; 587 if (dquot->dq_sb != sb) 588 continue; 589 /* Now we have active dquot so we can just increase use count */ 590 atomic_inc(&dquot->dq_count); 591 spin_unlock(&dq_list_lock); 592 dqstats_inc(DQST_LOOKUPS); 593 dqput(old_dquot); 594 old_dquot = dquot; 595 /* 596 * ->release_dquot() can be racing with us. Our reference 597 * protects us from new calls to it so just wait for any 598 * outstanding call and recheck the DQ_ACTIVE_B after that. 599 */ 600 wait_on_dquot(dquot); 601 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 602 ret = fn(dquot, priv); 603 if (ret < 0) 604 goto out; 605 } 606 spin_lock(&dq_list_lock); 607 /* We are safe to continue now because our dquot could not 608 * be moved out of the inuse list while we hold the reference */ 609 } 610 spin_unlock(&dq_list_lock); 611 out: 612 dqput(old_dquot); 613 return ret; 614 } 615 EXPORT_SYMBOL(dquot_scan_active); 616 617 /* Write all dquot structures to quota files */ 618 int dquot_writeback_dquots(struct super_block *sb, int type) 619 { 620 struct list_head *dirty; 621 struct dquot *dquot; 622 struct quota_info *dqopt = sb_dqopt(sb); 623 int cnt; 624 int err, ret = 0; 625 626 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 627 628 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 629 if (type != -1 && cnt != type) 630 continue; 631 if (!sb_has_quota_active(sb, cnt)) 632 continue; 633 spin_lock(&dq_list_lock); 634 dirty = &dqopt->info[cnt].dqi_dirty_list; 635 while (!list_empty(dirty)) { 636 dquot = list_first_entry(dirty, struct dquot, 637 dq_dirty); 638 639 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 640 641 /* Now we have active dquot from which someone is 642 * holding reference so we can safely just increase 643 * use count */ 644 dqgrab(dquot); 645 spin_unlock(&dq_list_lock); 646 dqstats_inc(DQST_LOOKUPS); 647 err = sb->dq_op->write_dquot(dquot); 648 if (err) { 649 /* 650 * Clear dirty bit anyway to avoid infinite 651 * loop here. 652 */ 653 clear_dquot_dirty(dquot); 654 if (!ret) 655 ret = err; 656 } 657 dqput(dquot); 658 spin_lock(&dq_list_lock); 659 } 660 spin_unlock(&dq_list_lock); 661 } 662 663 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 664 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 665 && info_dirty(&dqopt->info[cnt])) 666 sb->dq_op->write_info(sb, cnt); 667 dqstats_inc(DQST_SYNCS); 668 669 return ret; 670 } 671 EXPORT_SYMBOL(dquot_writeback_dquots); 672 673 /* Write all dquot structures to disk and make them visible from userspace */ 674 int dquot_quota_sync(struct super_block *sb, int type) 675 { 676 struct quota_info *dqopt = sb_dqopt(sb); 677 int cnt; 678 int ret; 679 680 ret = dquot_writeback_dquots(sb, type); 681 if (ret) 682 return ret; 683 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 684 return 0; 685 686 /* This is not very clever (and fast) but currently I don't know about 687 * any other simple way of getting quota data to disk and we must get 688 * them there for userspace to be visible... */ 689 if (sb->s_op->sync_fs) 690 sb->s_op->sync_fs(sb, 1); 691 sync_blockdev(sb->s_bdev); 692 693 /* 694 * Now when everything is written we can discard the pagecache so 695 * that userspace sees the changes. 696 */ 697 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 698 if (type != -1 && cnt != type) 699 continue; 700 if (!sb_has_quota_active(sb, cnt)) 701 continue; 702 inode_lock(dqopt->files[cnt]); 703 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 704 inode_unlock(dqopt->files[cnt]); 705 } 706 707 return 0; 708 } 709 EXPORT_SYMBOL(dquot_quota_sync); 710 711 static unsigned long 712 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 713 { 714 struct dquot *dquot; 715 unsigned long freed = 0; 716 717 spin_lock(&dq_list_lock); 718 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 719 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 720 remove_dquot_hash(dquot); 721 remove_free_dquot(dquot); 722 remove_inuse(dquot); 723 do_destroy_dquot(dquot); 724 sc->nr_to_scan--; 725 freed++; 726 } 727 spin_unlock(&dq_list_lock); 728 return freed; 729 } 730 731 static unsigned long 732 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 733 { 734 return vfs_pressure_ratio( 735 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 736 } 737 738 static struct shrinker dqcache_shrinker = { 739 .count_objects = dqcache_shrink_count, 740 .scan_objects = dqcache_shrink_scan, 741 .seeks = DEFAULT_SEEKS, 742 }; 743 744 /* 745 * Put reference to dquot 746 */ 747 void dqput(struct dquot *dquot) 748 { 749 int ret; 750 751 if (!dquot) 752 return; 753 #ifdef CONFIG_QUOTA_DEBUG 754 if (!atomic_read(&dquot->dq_count)) { 755 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 756 quotatypes[dquot->dq_id.type], 757 from_kqid(&init_user_ns, dquot->dq_id)); 758 BUG(); 759 } 760 #endif 761 dqstats_inc(DQST_DROPS); 762 we_slept: 763 spin_lock(&dq_list_lock); 764 if (atomic_read(&dquot->dq_count) > 1) { 765 /* We have more than one user... nothing to do */ 766 atomic_dec(&dquot->dq_count); 767 /* Releasing dquot during quotaoff phase? */ 768 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 769 atomic_read(&dquot->dq_count) == 1) 770 wake_up(&dquot_ref_wq); 771 spin_unlock(&dq_list_lock); 772 return; 773 } 774 /* Need to release dquot? */ 775 if (dquot_dirty(dquot)) { 776 spin_unlock(&dq_list_lock); 777 /* Commit dquot before releasing */ 778 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 779 if (ret < 0) { 780 quota_error(dquot->dq_sb, "Can't write quota structure" 781 " (error %d). Quota may get out of sync!", 782 ret); 783 /* 784 * We clear dirty bit anyway, so that we avoid 785 * infinite loop here 786 */ 787 clear_dquot_dirty(dquot); 788 } 789 goto we_slept; 790 } 791 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 792 spin_unlock(&dq_list_lock); 793 dquot->dq_sb->dq_op->release_dquot(dquot); 794 goto we_slept; 795 } 796 atomic_dec(&dquot->dq_count); 797 #ifdef CONFIG_QUOTA_DEBUG 798 /* sanity check */ 799 BUG_ON(!list_empty(&dquot->dq_free)); 800 #endif 801 put_dquot_last(dquot); 802 spin_unlock(&dq_list_lock); 803 } 804 EXPORT_SYMBOL(dqput); 805 806 struct dquot *dquot_alloc(struct super_block *sb, int type) 807 { 808 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 809 } 810 EXPORT_SYMBOL(dquot_alloc); 811 812 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 813 { 814 struct dquot *dquot; 815 816 dquot = sb->dq_op->alloc_dquot(sb, type); 817 if(!dquot) 818 return NULL; 819 820 mutex_init(&dquot->dq_lock); 821 INIT_LIST_HEAD(&dquot->dq_free); 822 INIT_LIST_HEAD(&dquot->dq_inuse); 823 INIT_HLIST_NODE(&dquot->dq_hash); 824 INIT_LIST_HEAD(&dquot->dq_dirty); 825 dquot->dq_sb = sb; 826 dquot->dq_id = make_kqid_invalid(type); 827 atomic_set(&dquot->dq_count, 1); 828 spin_lock_init(&dquot->dq_dqb_lock); 829 830 return dquot; 831 } 832 833 /* 834 * Get reference to dquot 835 * 836 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 837 * destroying our dquot by: 838 * a) checking for quota flags under dq_list_lock and 839 * b) getting a reference to dquot before we release dq_list_lock 840 */ 841 struct dquot *dqget(struct super_block *sb, struct kqid qid) 842 { 843 unsigned int hashent = hashfn(sb, qid); 844 struct dquot *dquot, *empty = NULL; 845 846 if (!qid_has_mapping(sb->s_user_ns, qid)) 847 return ERR_PTR(-EINVAL); 848 849 if (!sb_has_quota_active(sb, qid.type)) 850 return ERR_PTR(-ESRCH); 851 we_slept: 852 spin_lock(&dq_list_lock); 853 spin_lock(&dq_state_lock); 854 if (!sb_has_quota_active(sb, qid.type)) { 855 spin_unlock(&dq_state_lock); 856 spin_unlock(&dq_list_lock); 857 dquot = ERR_PTR(-ESRCH); 858 goto out; 859 } 860 spin_unlock(&dq_state_lock); 861 862 dquot = find_dquot(hashent, sb, qid); 863 if (!dquot) { 864 if (!empty) { 865 spin_unlock(&dq_list_lock); 866 empty = get_empty_dquot(sb, qid.type); 867 if (!empty) 868 schedule(); /* Try to wait for a moment... */ 869 goto we_slept; 870 } 871 dquot = empty; 872 empty = NULL; 873 dquot->dq_id = qid; 874 /* all dquots go on the inuse_list */ 875 put_inuse(dquot); 876 /* hash it first so it can be found */ 877 insert_dquot_hash(dquot); 878 spin_unlock(&dq_list_lock); 879 dqstats_inc(DQST_LOOKUPS); 880 } else { 881 if (!atomic_read(&dquot->dq_count)) 882 remove_free_dquot(dquot); 883 atomic_inc(&dquot->dq_count); 884 spin_unlock(&dq_list_lock); 885 dqstats_inc(DQST_CACHE_HITS); 886 dqstats_inc(DQST_LOOKUPS); 887 } 888 /* Wait for dq_lock - after this we know that either dquot_release() is 889 * already finished or it will be canceled due to dq_count > 1 test */ 890 wait_on_dquot(dquot); 891 /* Read the dquot / allocate space in quota file */ 892 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 893 int err; 894 895 err = sb->dq_op->acquire_dquot(dquot); 896 if (err < 0) { 897 dqput(dquot); 898 dquot = ERR_PTR(err); 899 goto out; 900 } 901 } 902 /* 903 * Make sure following reads see filled structure - paired with 904 * smp_mb__before_atomic() in dquot_acquire(). 905 */ 906 smp_rmb(); 907 #ifdef CONFIG_QUOTA_DEBUG 908 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 909 #endif 910 out: 911 if (empty) 912 do_destroy_dquot(empty); 913 914 return dquot; 915 } 916 EXPORT_SYMBOL(dqget); 917 918 static inline struct dquot **i_dquot(struct inode *inode) 919 { 920 return inode->i_sb->s_op->get_dquots(inode); 921 } 922 923 static int dqinit_needed(struct inode *inode, int type) 924 { 925 struct dquot * const *dquots; 926 int cnt; 927 928 if (IS_NOQUOTA(inode)) 929 return 0; 930 931 dquots = i_dquot(inode); 932 if (type != -1) 933 return !dquots[type]; 934 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 935 if (!dquots[cnt]) 936 return 1; 937 return 0; 938 } 939 940 /* This routine is guarded by s_umount semaphore */ 941 static int add_dquot_ref(struct super_block *sb, int type) 942 { 943 struct inode *inode, *old_inode = NULL; 944 #ifdef CONFIG_QUOTA_DEBUG 945 int reserved = 0; 946 #endif 947 int err = 0; 948 949 spin_lock(&sb->s_inode_list_lock); 950 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 951 spin_lock(&inode->i_lock); 952 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 953 !atomic_read(&inode->i_writecount) || 954 !dqinit_needed(inode, type)) { 955 spin_unlock(&inode->i_lock); 956 continue; 957 } 958 __iget(inode); 959 spin_unlock(&inode->i_lock); 960 spin_unlock(&sb->s_inode_list_lock); 961 962 #ifdef CONFIG_QUOTA_DEBUG 963 if (unlikely(inode_get_rsv_space(inode) > 0)) 964 reserved = 1; 965 #endif 966 iput(old_inode); 967 err = __dquot_initialize(inode, type); 968 if (err) { 969 iput(inode); 970 goto out; 971 } 972 973 /* 974 * We hold a reference to 'inode' so it couldn't have been 975 * removed from s_inodes list while we dropped the 976 * s_inode_list_lock. We cannot iput the inode now as we can be 977 * holding the last reference and we cannot iput it under 978 * s_inode_list_lock. So we keep the reference and iput it 979 * later. 980 */ 981 old_inode = inode; 982 spin_lock(&sb->s_inode_list_lock); 983 } 984 spin_unlock(&sb->s_inode_list_lock); 985 iput(old_inode); 986 out: 987 #ifdef CONFIG_QUOTA_DEBUG 988 if (reserved) { 989 quota_error(sb, "Writes happened before quota was turned on " 990 "thus quota information is probably inconsistent. " 991 "Please run quotacheck(8)"); 992 } 993 #endif 994 return err; 995 } 996 997 /* 998 * Remove references to dquots from inode and add dquot to list for freeing 999 * if we have the last reference to dquot 1000 */ 1001 static void remove_inode_dquot_ref(struct inode *inode, int type, 1002 struct list_head *tofree_head) 1003 { 1004 struct dquot **dquots = i_dquot(inode); 1005 struct dquot *dquot = dquots[type]; 1006 1007 if (!dquot) 1008 return; 1009 1010 dquots[type] = NULL; 1011 if (list_empty(&dquot->dq_free)) { 1012 /* 1013 * The inode still has reference to dquot so it can't be in the 1014 * free list 1015 */ 1016 spin_lock(&dq_list_lock); 1017 list_add(&dquot->dq_free, tofree_head); 1018 spin_unlock(&dq_list_lock); 1019 } else { 1020 /* 1021 * Dquot is already in a list to put so we won't drop the last 1022 * reference here. 1023 */ 1024 dqput(dquot); 1025 } 1026 } 1027 1028 /* 1029 * Free list of dquots 1030 * Dquots are removed from inodes and no new references can be got so we are 1031 * the only ones holding reference 1032 */ 1033 static void put_dquot_list(struct list_head *tofree_head) 1034 { 1035 struct list_head *act_head; 1036 struct dquot *dquot; 1037 1038 act_head = tofree_head->next; 1039 while (act_head != tofree_head) { 1040 dquot = list_entry(act_head, struct dquot, dq_free); 1041 act_head = act_head->next; 1042 /* Remove dquot from the list so we won't have problems... */ 1043 list_del_init(&dquot->dq_free); 1044 dqput(dquot); 1045 } 1046 } 1047 1048 static void remove_dquot_ref(struct super_block *sb, int type, 1049 struct list_head *tofree_head) 1050 { 1051 struct inode *inode; 1052 int reserved = 0; 1053 1054 spin_lock(&sb->s_inode_list_lock); 1055 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1056 /* 1057 * We have to scan also I_NEW inodes because they can already 1058 * have quota pointer initialized. Luckily, we need to touch 1059 * only quota pointers and these have separate locking 1060 * (dq_data_lock). 1061 */ 1062 spin_lock(&dq_data_lock); 1063 if (!IS_NOQUOTA(inode)) { 1064 if (unlikely(inode_get_rsv_space(inode) > 0)) 1065 reserved = 1; 1066 remove_inode_dquot_ref(inode, type, tofree_head); 1067 } 1068 spin_unlock(&dq_data_lock); 1069 } 1070 spin_unlock(&sb->s_inode_list_lock); 1071 #ifdef CONFIG_QUOTA_DEBUG 1072 if (reserved) { 1073 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1074 " was disabled thus quota information is probably " 1075 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1076 } 1077 #endif 1078 } 1079 1080 /* Gather all references from inodes and drop them */ 1081 static void drop_dquot_ref(struct super_block *sb, int type) 1082 { 1083 LIST_HEAD(tofree_head); 1084 1085 if (sb->dq_op) { 1086 remove_dquot_ref(sb, type, &tofree_head); 1087 synchronize_srcu(&dquot_srcu); 1088 put_dquot_list(&tofree_head); 1089 } 1090 } 1091 1092 static inline 1093 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1094 { 1095 if (dquot->dq_dqb.dqb_rsvspace >= number) 1096 dquot->dq_dqb.dqb_rsvspace -= number; 1097 else { 1098 WARN_ON_ONCE(1); 1099 dquot->dq_dqb.dqb_rsvspace = 0; 1100 } 1101 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1102 dquot->dq_dqb.dqb_bsoftlimit) 1103 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1104 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1105 } 1106 1107 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1108 { 1109 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1110 dquot->dq_dqb.dqb_curinodes >= number) 1111 dquot->dq_dqb.dqb_curinodes -= number; 1112 else 1113 dquot->dq_dqb.dqb_curinodes = 0; 1114 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1115 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1116 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1117 } 1118 1119 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1120 { 1121 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1122 dquot->dq_dqb.dqb_curspace >= number) 1123 dquot->dq_dqb.dqb_curspace -= number; 1124 else 1125 dquot->dq_dqb.dqb_curspace = 0; 1126 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1127 dquot->dq_dqb.dqb_bsoftlimit) 1128 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1129 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1130 } 1131 1132 struct dquot_warn { 1133 struct super_block *w_sb; 1134 struct kqid w_dq_id; 1135 short w_type; 1136 }; 1137 1138 static int warning_issued(struct dquot *dquot, const int warntype) 1139 { 1140 int flag = (warntype == QUOTA_NL_BHARDWARN || 1141 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1142 ((warntype == QUOTA_NL_IHARDWARN || 1143 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1144 1145 if (!flag) 1146 return 0; 1147 return test_and_set_bit(flag, &dquot->dq_flags); 1148 } 1149 1150 #ifdef CONFIG_PRINT_QUOTA_WARNING 1151 static int flag_print_warnings = 1; 1152 1153 static int need_print_warning(struct dquot_warn *warn) 1154 { 1155 if (!flag_print_warnings) 1156 return 0; 1157 1158 switch (warn->w_dq_id.type) { 1159 case USRQUOTA: 1160 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1161 case GRPQUOTA: 1162 return in_group_p(warn->w_dq_id.gid); 1163 case PRJQUOTA: 1164 return 1; 1165 } 1166 return 0; 1167 } 1168 1169 /* Print warning to user which exceeded quota */ 1170 static void print_warning(struct dquot_warn *warn) 1171 { 1172 char *msg = NULL; 1173 struct tty_struct *tty; 1174 int warntype = warn->w_type; 1175 1176 if (warntype == QUOTA_NL_IHARDBELOW || 1177 warntype == QUOTA_NL_ISOFTBELOW || 1178 warntype == QUOTA_NL_BHARDBELOW || 1179 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1180 return; 1181 1182 tty = get_current_tty(); 1183 if (!tty) 1184 return; 1185 tty_write_message(tty, warn->w_sb->s_id); 1186 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1187 tty_write_message(tty, ": warning, "); 1188 else 1189 tty_write_message(tty, ": write failed, "); 1190 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1191 switch (warntype) { 1192 case QUOTA_NL_IHARDWARN: 1193 msg = " file limit reached.\r\n"; 1194 break; 1195 case QUOTA_NL_ISOFTLONGWARN: 1196 msg = " file quota exceeded too long.\r\n"; 1197 break; 1198 case QUOTA_NL_ISOFTWARN: 1199 msg = " file quota exceeded.\r\n"; 1200 break; 1201 case QUOTA_NL_BHARDWARN: 1202 msg = " block limit reached.\r\n"; 1203 break; 1204 case QUOTA_NL_BSOFTLONGWARN: 1205 msg = " block quota exceeded too long.\r\n"; 1206 break; 1207 case QUOTA_NL_BSOFTWARN: 1208 msg = " block quota exceeded.\r\n"; 1209 break; 1210 } 1211 tty_write_message(tty, msg); 1212 tty_kref_put(tty); 1213 } 1214 #endif 1215 1216 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1217 int warntype) 1218 { 1219 if (warning_issued(dquot, warntype)) 1220 return; 1221 warn->w_type = warntype; 1222 warn->w_sb = dquot->dq_sb; 1223 warn->w_dq_id = dquot->dq_id; 1224 } 1225 1226 /* 1227 * Write warnings to the console and send warning messages over netlink. 1228 * 1229 * Note that this function can call into tty and networking code. 1230 */ 1231 static void flush_warnings(struct dquot_warn *warn) 1232 { 1233 int i; 1234 1235 for (i = 0; i < MAXQUOTAS; i++) { 1236 if (warn[i].w_type == QUOTA_NL_NOWARN) 1237 continue; 1238 #ifdef CONFIG_PRINT_QUOTA_WARNING 1239 print_warning(&warn[i]); 1240 #endif 1241 quota_send_warning(warn[i].w_dq_id, 1242 warn[i].w_sb->s_dev, warn[i].w_type); 1243 } 1244 } 1245 1246 static int ignore_hardlimit(struct dquot *dquot) 1247 { 1248 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1249 1250 return capable(CAP_SYS_RESOURCE) && 1251 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1252 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1253 } 1254 1255 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1256 struct dquot_warn *warn) 1257 { 1258 qsize_t newinodes; 1259 int ret = 0; 1260 1261 spin_lock(&dquot->dq_dqb_lock); 1262 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1263 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1264 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1265 goto add; 1266 1267 if (dquot->dq_dqb.dqb_ihardlimit && 1268 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1269 !ignore_hardlimit(dquot)) { 1270 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1271 ret = -EDQUOT; 1272 goto out; 1273 } 1274 1275 if (dquot->dq_dqb.dqb_isoftlimit && 1276 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1277 dquot->dq_dqb.dqb_itime && 1278 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1279 !ignore_hardlimit(dquot)) { 1280 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1281 ret = -EDQUOT; 1282 goto out; 1283 } 1284 1285 if (dquot->dq_dqb.dqb_isoftlimit && 1286 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1287 dquot->dq_dqb.dqb_itime == 0) { 1288 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1289 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1290 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1291 } 1292 add: 1293 dquot->dq_dqb.dqb_curinodes = newinodes; 1294 1295 out: 1296 spin_unlock(&dquot->dq_dqb_lock); 1297 return ret; 1298 } 1299 1300 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1301 qsize_t rsv_space, unsigned int flags, 1302 struct dquot_warn *warn) 1303 { 1304 qsize_t tspace; 1305 struct super_block *sb = dquot->dq_sb; 1306 int ret = 0; 1307 1308 spin_lock(&dquot->dq_dqb_lock); 1309 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1310 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1311 goto finish; 1312 1313 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1314 + space + rsv_space; 1315 1316 if (dquot->dq_dqb.dqb_bhardlimit && 1317 tspace > dquot->dq_dqb.dqb_bhardlimit && 1318 !ignore_hardlimit(dquot)) { 1319 if (flags & DQUOT_SPACE_WARN) 1320 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1321 ret = -EDQUOT; 1322 goto finish; 1323 } 1324 1325 if (dquot->dq_dqb.dqb_bsoftlimit && 1326 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1327 dquot->dq_dqb.dqb_btime && 1328 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1329 !ignore_hardlimit(dquot)) { 1330 if (flags & DQUOT_SPACE_WARN) 1331 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1332 ret = -EDQUOT; 1333 goto finish; 1334 } 1335 1336 if (dquot->dq_dqb.dqb_bsoftlimit && 1337 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1338 dquot->dq_dqb.dqb_btime == 0) { 1339 if (flags & DQUOT_SPACE_WARN) { 1340 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1341 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1342 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1343 } else { 1344 /* 1345 * We don't allow preallocation to exceed softlimit so exceeding will 1346 * be always printed 1347 */ 1348 ret = -EDQUOT; 1349 goto finish; 1350 } 1351 } 1352 finish: 1353 /* 1354 * We have to be careful and go through warning generation & grace time 1355 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1356 * only here... 1357 */ 1358 if (flags & DQUOT_SPACE_NOFAIL) 1359 ret = 0; 1360 if (!ret) { 1361 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1362 dquot->dq_dqb.dqb_curspace += space; 1363 } 1364 spin_unlock(&dquot->dq_dqb_lock); 1365 return ret; 1366 } 1367 1368 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1369 { 1370 qsize_t newinodes; 1371 1372 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1373 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1374 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1375 return QUOTA_NL_NOWARN; 1376 1377 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1378 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1379 return QUOTA_NL_ISOFTBELOW; 1380 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1381 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1382 return QUOTA_NL_IHARDBELOW; 1383 return QUOTA_NL_NOWARN; 1384 } 1385 1386 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1387 { 1388 qsize_t tspace; 1389 1390 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1391 1392 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1393 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1394 return QUOTA_NL_NOWARN; 1395 1396 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1397 return QUOTA_NL_BSOFTBELOW; 1398 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1399 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1400 return QUOTA_NL_BHARDBELOW; 1401 return QUOTA_NL_NOWARN; 1402 } 1403 1404 static int dquot_active(const struct inode *inode) 1405 { 1406 struct super_block *sb = inode->i_sb; 1407 1408 if (IS_NOQUOTA(inode)) 1409 return 0; 1410 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1411 } 1412 1413 /* 1414 * Initialize quota pointers in inode 1415 * 1416 * It is better to call this function outside of any transaction as it 1417 * might need a lot of space in journal for dquot structure allocation. 1418 */ 1419 static int __dquot_initialize(struct inode *inode, int type) 1420 { 1421 int cnt, init_needed = 0; 1422 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1423 struct super_block *sb = inode->i_sb; 1424 qsize_t rsv; 1425 int ret = 0; 1426 1427 if (!dquot_active(inode)) 1428 return 0; 1429 1430 dquots = i_dquot(inode); 1431 1432 /* First get references to structures we might need. */ 1433 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1434 struct kqid qid; 1435 kprojid_t projid; 1436 int rc; 1437 struct dquot *dquot; 1438 1439 if (type != -1 && cnt != type) 1440 continue; 1441 /* 1442 * The i_dquot should have been initialized in most cases, 1443 * we check it without locking here to avoid unnecessary 1444 * dqget()/dqput() calls. 1445 */ 1446 if (dquots[cnt]) 1447 continue; 1448 1449 if (!sb_has_quota_active(sb, cnt)) 1450 continue; 1451 1452 init_needed = 1; 1453 1454 switch (cnt) { 1455 case USRQUOTA: 1456 qid = make_kqid_uid(inode->i_uid); 1457 break; 1458 case GRPQUOTA: 1459 qid = make_kqid_gid(inode->i_gid); 1460 break; 1461 case PRJQUOTA: 1462 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1463 if (rc) 1464 continue; 1465 qid = make_kqid_projid(projid); 1466 break; 1467 } 1468 dquot = dqget(sb, qid); 1469 if (IS_ERR(dquot)) { 1470 /* We raced with somebody turning quotas off... */ 1471 if (PTR_ERR(dquot) != -ESRCH) { 1472 ret = PTR_ERR(dquot); 1473 goto out_put; 1474 } 1475 dquot = NULL; 1476 } 1477 got[cnt] = dquot; 1478 } 1479 1480 /* All required i_dquot has been initialized */ 1481 if (!init_needed) 1482 return 0; 1483 1484 spin_lock(&dq_data_lock); 1485 if (IS_NOQUOTA(inode)) 1486 goto out_lock; 1487 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1488 if (type != -1 && cnt != type) 1489 continue; 1490 /* Avoid races with quotaoff() */ 1491 if (!sb_has_quota_active(sb, cnt)) 1492 continue; 1493 /* We could race with quotaon or dqget() could have failed */ 1494 if (!got[cnt]) 1495 continue; 1496 if (!dquots[cnt]) { 1497 dquots[cnt] = got[cnt]; 1498 got[cnt] = NULL; 1499 /* 1500 * Make quota reservation system happy if someone 1501 * did a write before quota was turned on 1502 */ 1503 rsv = inode_get_rsv_space(inode); 1504 if (unlikely(rsv)) { 1505 spin_lock(&inode->i_lock); 1506 /* Get reservation again under proper lock */ 1507 rsv = __inode_get_rsv_space(inode); 1508 spin_lock(&dquots[cnt]->dq_dqb_lock); 1509 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1510 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1511 spin_unlock(&inode->i_lock); 1512 } 1513 } 1514 } 1515 out_lock: 1516 spin_unlock(&dq_data_lock); 1517 out_put: 1518 /* Drop unused references */ 1519 dqput_all(got); 1520 1521 return ret; 1522 } 1523 1524 int dquot_initialize(struct inode *inode) 1525 { 1526 return __dquot_initialize(inode, -1); 1527 } 1528 EXPORT_SYMBOL(dquot_initialize); 1529 1530 bool dquot_initialize_needed(struct inode *inode) 1531 { 1532 struct dquot **dquots; 1533 int i; 1534 1535 if (!dquot_active(inode)) 1536 return false; 1537 1538 dquots = i_dquot(inode); 1539 for (i = 0; i < MAXQUOTAS; i++) 1540 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1541 return true; 1542 return false; 1543 } 1544 EXPORT_SYMBOL(dquot_initialize_needed); 1545 1546 /* 1547 * Release all quotas referenced by inode. 1548 * 1549 * This function only be called on inode free or converting 1550 * a file to quota file, no other users for the i_dquot in 1551 * both cases, so we needn't call synchronize_srcu() after 1552 * clearing i_dquot. 1553 */ 1554 static void __dquot_drop(struct inode *inode) 1555 { 1556 int cnt; 1557 struct dquot **dquots = i_dquot(inode); 1558 struct dquot *put[MAXQUOTAS]; 1559 1560 spin_lock(&dq_data_lock); 1561 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1562 put[cnt] = dquots[cnt]; 1563 dquots[cnt] = NULL; 1564 } 1565 spin_unlock(&dq_data_lock); 1566 dqput_all(put); 1567 } 1568 1569 void dquot_drop(struct inode *inode) 1570 { 1571 struct dquot * const *dquots; 1572 int cnt; 1573 1574 if (IS_NOQUOTA(inode)) 1575 return; 1576 1577 /* 1578 * Test before calling to rule out calls from proc and such 1579 * where we are not allowed to block. Note that this is 1580 * actually reliable test even without the lock - the caller 1581 * must assure that nobody can come after the DQUOT_DROP and 1582 * add quota pointers back anyway. 1583 */ 1584 dquots = i_dquot(inode); 1585 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1586 if (dquots[cnt]) 1587 break; 1588 } 1589 1590 if (cnt < MAXQUOTAS) 1591 __dquot_drop(inode); 1592 } 1593 EXPORT_SYMBOL(dquot_drop); 1594 1595 /* 1596 * inode_reserved_space is managed internally by quota, and protected by 1597 * i_lock similar to i_blocks+i_bytes. 1598 */ 1599 static qsize_t *inode_reserved_space(struct inode * inode) 1600 { 1601 /* Filesystem must explicitly define it's own method in order to use 1602 * quota reservation interface */ 1603 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1604 return inode->i_sb->dq_op->get_reserved_space(inode); 1605 } 1606 1607 static qsize_t __inode_get_rsv_space(struct inode *inode) 1608 { 1609 if (!inode->i_sb->dq_op->get_reserved_space) 1610 return 0; 1611 return *inode_reserved_space(inode); 1612 } 1613 1614 static qsize_t inode_get_rsv_space(struct inode *inode) 1615 { 1616 qsize_t ret; 1617 1618 if (!inode->i_sb->dq_op->get_reserved_space) 1619 return 0; 1620 spin_lock(&inode->i_lock); 1621 ret = __inode_get_rsv_space(inode); 1622 spin_unlock(&inode->i_lock); 1623 return ret; 1624 } 1625 1626 /* 1627 * This functions updates i_blocks+i_bytes fields and quota information 1628 * (together with appropriate checks). 1629 * 1630 * NOTE: We absolutely rely on the fact that caller dirties the inode 1631 * (usually helpers in quotaops.h care about this) and holds a handle for 1632 * the current transaction so that dquot write and inode write go into the 1633 * same transaction. 1634 */ 1635 1636 /* 1637 * This operation can block, but only after everything is updated 1638 */ 1639 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1640 { 1641 int cnt, ret = 0, index; 1642 struct dquot_warn warn[MAXQUOTAS]; 1643 int reserve = flags & DQUOT_SPACE_RESERVE; 1644 struct dquot **dquots; 1645 1646 if (!dquot_active(inode)) { 1647 if (reserve) { 1648 spin_lock(&inode->i_lock); 1649 *inode_reserved_space(inode) += number; 1650 spin_unlock(&inode->i_lock); 1651 } else { 1652 inode_add_bytes(inode, number); 1653 } 1654 goto out; 1655 } 1656 1657 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1658 warn[cnt].w_type = QUOTA_NL_NOWARN; 1659 1660 dquots = i_dquot(inode); 1661 index = srcu_read_lock(&dquot_srcu); 1662 spin_lock(&inode->i_lock); 1663 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1664 if (!dquots[cnt]) 1665 continue; 1666 if (flags & DQUOT_SPACE_RESERVE) { 1667 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1668 &warn[cnt]); 1669 } else { 1670 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1671 &warn[cnt]); 1672 } 1673 if (ret) { 1674 /* Back out changes we already did */ 1675 for (cnt--; cnt >= 0; cnt--) { 1676 if (!dquots[cnt]) 1677 continue; 1678 spin_lock(&dquots[cnt]->dq_dqb_lock); 1679 if (flags & DQUOT_SPACE_RESERVE) { 1680 dquots[cnt]->dq_dqb.dqb_rsvspace -= 1681 number; 1682 } else { 1683 dquots[cnt]->dq_dqb.dqb_curspace -= 1684 number; 1685 } 1686 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1687 } 1688 spin_unlock(&inode->i_lock); 1689 goto out_flush_warn; 1690 } 1691 } 1692 if (reserve) 1693 *inode_reserved_space(inode) += number; 1694 else 1695 __inode_add_bytes(inode, number); 1696 spin_unlock(&inode->i_lock); 1697 1698 if (reserve) 1699 goto out_flush_warn; 1700 mark_all_dquot_dirty(dquots); 1701 out_flush_warn: 1702 srcu_read_unlock(&dquot_srcu, index); 1703 flush_warnings(warn); 1704 out: 1705 return ret; 1706 } 1707 EXPORT_SYMBOL(__dquot_alloc_space); 1708 1709 /* 1710 * This operation can block, but only after everything is updated 1711 */ 1712 int dquot_alloc_inode(struct inode *inode) 1713 { 1714 int cnt, ret = 0, index; 1715 struct dquot_warn warn[MAXQUOTAS]; 1716 struct dquot * const *dquots; 1717 1718 if (!dquot_active(inode)) 1719 return 0; 1720 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1721 warn[cnt].w_type = QUOTA_NL_NOWARN; 1722 1723 dquots = i_dquot(inode); 1724 index = srcu_read_lock(&dquot_srcu); 1725 spin_lock(&inode->i_lock); 1726 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1727 if (!dquots[cnt]) 1728 continue; 1729 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1730 if (ret) { 1731 for (cnt--; cnt >= 0; cnt--) { 1732 if (!dquots[cnt]) 1733 continue; 1734 /* Back out changes we already did */ 1735 spin_lock(&dquots[cnt]->dq_dqb_lock); 1736 dquots[cnt]->dq_dqb.dqb_curinodes--; 1737 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1738 } 1739 goto warn_put_all; 1740 } 1741 } 1742 1743 warn_put_all: 1744 spin_unlock(&inode->i_lock); 1745 if (ret == 0) 1746 mark_all_dquot_dirty(dquots); 1747 srcu_read_unlock(&dquot_srcu, index); 1748 flush_warnings(warn); 1749 return ret; 1750 } 1751 EXPORT_SYMBOL(dquot_alloc_inode); 1752 1753 /* 1754 * Convert in-memory reserved quotas to real consumed quotas 1755 */ 1756 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1757 { 1758 struct dquot **dquots; 1759 int cnt, index; 1760 1761 if (!dquot_active(inode)) { 1762 spin_lock(&inode->i_lock); 1763 *inode_reserved_space(inode) -= number; 1764 __inode_add_bytes(inode, number); 1765 spin_unlock(&inode->i_lock); 1766 return 0; 1767 } 1768 1769 dquots = i_dquot(inode); 1770 index = srcu_read_lock(&dquot_srcu); 1771 spin_lock(&inode->i_lock); 1772 /* Claim reserved quotas to allocated quotas */ 1773 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1774 if (dquots[cnt]) { 1775 struct dquot *dquot = dquots[cnt]; 1776 1777 spin_lock(&dquot->dq_dqb_lock); 1778 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1779 number = dquot->dq_dqb.dqb_rsvspace; 1780 dquot->dq_dqb.dqb_curspace += number; 1781 dquot->dq_dqb.dqb_rsvspace -= number; 1782 spin_unlock(&dquot->dq_dqb_lock); 1783 } 1784 } 1785 /* Update inode bytes */ 1786 *inode_reserved_space(inode) -= number; 1787 __inode_add_bytes(inode, number); 1788 spin_unlock(&inode->i_lock); 1789 mark_all_dquot_dirty(dquots); 1790 srcu_read_unlock(&dquot_srcu, index); 1791 return 0; 1792 } 1793 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1794 1795 /* 1796 * Convert allocated space back to in-memory reserved quotas 1797 */ 1798 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1799 { 1800 struct dquot **dquots; 1801 int cnt, index; 1802 1803 if (!dquot_active(inode)) { 1804 spin_lock(&inode->i_lock); 1805 *inode_reserved_space(inode) += number; 1806 __inode_sub_bytes(inode, number); 1807 spin_unlock(&inode->i_lock); 1808 return; 1809 } 1810 1811 dquots = i_dquot(inode); 1812 index = srcu_read_lock(&dquot_srcu); 1813 spin_lock(&inode->i_lock); 1814 /* Claim reserved quotas to allocated quotas */ 1815 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1816 if (dquots[cnt]) { 1817 struct dquot *dquot = dquots[cnt]; 1818 1819 spin_lock(&dquot->dq_dqb_lock); 1820 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1821 number = dquot->dq_dqb.dqb_curspace; 1822 dquot->dq_dqb.dqb_rsvspace += number; 1823 dquot->dq_dqb.dqb_curspace -= number; 1824 spin_unlock(&dquot->dq_dqb_lock); 1825 } 1826 } 1827 /* Update inode bytes */ 1828 *inode_reserved_space(inode) += number; 1829 __inode_sub_bytes(inode, number); 1830 spin_unlock(&inode->i_lock); 1831 mark_all_dquot_dirty(dquots); 1832 srcu_read_unlock(&dquot_srcu, index); 1833 return; 1834 } 1835 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1836 1837 /* 1838 * This operation can block, but only after everything is updated 1839 */ 1840 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1841 { 1842 unsigned int cnt; 1843 struct dquot_warn warn[MAXQUOTAS]; 1844 struct dquot **dquots; 1845 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1846 1847 if (!dquot_active(inode)) { 1848 if (reserve) { 1849 spin_lock(&inode->i_lock); 1850 *inode_reserved_space(inode) -= number; 1851 spin_unlock(&inode->i_lock); 1852 } else { 1853 inode_sub_bytes(inode, number); 1854 } 1855 return; 1856 } 1857 1858 dquots = i_dquot(inode); 1859 index = srcu_read_lock(&dquot_srcu); 1860 spin_lock(&inode->i_lock); 1861 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1862 int wtype; 1863 1864 warn[cnt].w_type = QUOTA_NL_NOWARN; 1865 if (!dquots[cnt]) 1866 continue; 1867 spin_lock(&dquots[cnt]->dq_dqb_lock); 1868 wtype = info_bdq_free(dquots[cnt], number); 1869 if (wtype != QUOTA_NL_NOWARN) 1870 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1871 if (reserve) 1872 dquot_free_reserved_space(dquots[cnt], number); 1873 else 1874 dquot_decr_space(dquots[cnt], number); 1875 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1876 } 1877 if (reserve) 1878 *inode_reserved_space(inode) -= number; 1879 else 1880 __inode_sub_bytes(inode, number); 1881 spin_unlock(&inode->i_lock); 1882 1883 if (reserve) 1884 goto out_unlock; 1885 mark_all_dquot_dirty(dquots); 1886 out_unlock: 1887 srcu_read_unlock(&dquot_srcu, index); 1888 flush_warnings(warn); 1889 } 1890 EXPORT_SYMBOL(__dquot_free_space); 1891 1892 /* 1893 * This operation can block, but only after everything is updated 1894 */ 1895 void dquot_free_inode(struct inode *inode) 1896 { 1897 unsigned int cnt; 1898 struct dquot_warn warn[MAXQUOTAS]; 1899 struct dquot * const *dquots; 1900 int index; 1901 1902 if (!dquot_active(inode)) 1903 return; 1904 1905 dquots = i_dquot(inode); 1906 index = srcu_read_lock(&dquot_srcu); 1907 spin_lock(&inode->i_lock); 1908 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1909 int wtype; 1910 1911 warn[cnt].w_type = QUOTA_NL_NOWARN; 1912 if (!dquots[cnt]) 1913 continue; 1914 spin_lock(&dquots[cnt]->dq_dqb_lock); 1915 wtype = info_idq_free(dquots[cnt], 1); 1916 if (wtype != QUOTA_NL_NOWARN) 1917 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1918 dquot_decr_inodes(dquots[cnt], 1); 1919 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1920 } 1921 spin_unlock(&inode->i_lock); 1922 mark_all_dquot_dirty(dquots); 1923 srcu_read_unlock(&dquot_srcu, index); 1924 flush_warnings(warn); 1925 } 1926 EXPORT_SYMBOL(dquot_free_inode); 1927 1928 /* 1929 * Transfer the number of inode and blocks from one diskquota to an other. 1930 * On success, dquot references in transfer_to are consumed and references 1931 * to original dquots that need to be released are placed there. On failure, 1932 * references are kept untouched. 1933 * 1934 * This operation can block, but only after everything is updated 1935 * A transaction must be started when entering this function. 1936 * 1937 * We are holding reference on transfer_from & transfer_to, no need to 1938 * protect them by srcu_read_lock(). 1939 */ 1940 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1941 { 1942 qsize_t cur_space; 1943 qsize_t rsv_space = 0; 1944 qsize_t inode_usage = 1; 1945 struct dquot *transfer_from[MAXQUOTAS] = {}; 1946 int cnt, ret = 0; 1947 char is_valid[MAXQUOTAS] = {}; 1948 struct dquot_warn warn_to[MAXQUOTAS]; 1949 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1950 struct dquot_warn warn_from_space[MAXQUOTAS]; 1951 1952 if (IS_NOQUOTA(inode)) 1953 return 0; 1954 1955 if (inode->i_sb->dq_op->get_inode_usage) { 1956 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1957 if (ret) 1958 return ret; 1959 } 1960 1961 /* Initialize the arrays */ 1962 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1963 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1964 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1965 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1966 } 1967 1968 spin_lock(&dq_data_lock); 1969 spin_lock(&inode->i_lock); 1970 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1971 spin_unlock(&inode->i_lock); 1972 spin_unlock(&dq_data_lock); 1973 return 0; 1974 } 1975 cur_space = __inode_get_bytes(inode); 1976 rsv_space = __inode_get_rsv_space(inode); 1977 /* 1978 * Build the transfer_from list, check limits, and update usage in 1979 * the target structures. 1980 */ 1981 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1982 /* 1983 * Skip changes for same uid or gid or for turned off quota-type. 1984 */ 1985 if (!transfer_to[cnt]) 1986 continue; 1987 /* Avoid races with quotaoff() */ 1988 if (!sb_has_quota_active(inode->i_sb, cnt)) 1989 continue; 1990 is_valid[cnt] = 1; 1991 transfer_from[cnt] = i_dquot(inode)[cnt]; 1992 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 1993 &warn_to[cnt]); 1994 if (ret) 1995 goto over_quota; 1996 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 0, 1997 &warn_to[cnt]); 1998 if (ret) { 1999 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2000 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2001 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2002 goto over_quota; 2003 } 2004 } 2005 2006 /* Decrease usage for source structures and update quota pointers */ 2007 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2008 if (!is_valid[cnt]) 2009 continue; 2010 /* Due to IO error we might not have transfer_from[] structure */ 2011 if (transfer_from[cnt]) { 2012 int wtype; 2013 2014 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2015 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2016 if (wtype != QUOTA_NL_NOWARN) 2017 prepare_warning(&warn_from_inodes[cnt], 2018 transfer_from[cnt], wtype); 2019 wtype = info_bdq_free(transfer_from[cnt], 2020 cur_space + rsv_space); 2021 if (wtype != QUOTA_NL_NOWARN) 2022 prepare_warning(&warn_from_space[cnt], 2023 transfer_from[cnt], wtype); 2024 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2025 dquot_decr_space(transfer_from[cnt], cur_space); 2026 dquot_free_reserved_space(transfer_from[cnt], 2027 rsv_space); 2028 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2029 } 2030 i_dquot(inode)[cnt] = transfer_to[cnt]; 2031 } 2032 spin_unlock(&inode->i_lock); 2033 spin_unlock(&dq_data_lock); 2034 2035 mark_all_dquot_dirty(transfer_from); 2036 mark_all_dquot_dirty(transfer_to); 2037 flush_warnings(warn_to); 2038 flush_warnings(warn_from_inodes); 2039 flush_warnings(warn_from_space); 2040 /* Pass back references to put */ 2041 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2042 if (is_valid[cnt]) 2043 transfer_to[cnt] = transfer_from[cnt]; 2044 return 0; 2045 over_quota: 2046 /* Back out changes we already did */ 2047 for (cnt--; cnt >= 0; cnt--) { 2048 if (!is_valid[cnt]) 2049 continue; 2050 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2051 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2052 dquot_decr_space(transfer_to[cnt], cur_space); 2053 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2054 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2055 } 2056 spin_unlock(&inode->i_lock); 2057 spin_unlock(&dq_data_lock); 2058 flush_warnings(warn_to); 2059 return ret; 2060 } 2061 EXPORT_SYMBOL(__dquot_transfer); 2062 2063 /* Wrapper for transferring ownership of an inode for uid/gid only 2064 * Called from FSXXX_setattr() 2065 */ 2066 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2067 { 2068 struct dquot *transfer_to[MAXQUOTAS] = {}; 2069 struct dquot *dquot; 2070 struct super_block *sb = inode->i_sb; 2071 int ret; 2072 2073 if (!dquot_active(inode)) 2074 return 0; 2075 2076 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2077 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2078 if (IS_ERR(dquot)) { 2079 if (PTR_ERR(dquot) != -ESRCH) { 2080 ret = PTR_ERR(dquot); 2081 goto out_put; 2082 } 2083 dquot = NULL; 2084 } 2085 transfer_to[USRQUOTA] = dquot; 2086 } 2087 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2088 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2089 if (IS_ERR(dquot)) { 2090 if (PTR_ERR(dquot) != -ESRCH) { 2091 ret = PTR_ERR(dquot); 2092 goto out_put; 2093 } 2094 dquot = NULL; 2095 } 2096 transfer_to[GRPQUOTA] = dquot; 2097 } 2098 ret = __dquot_transfer(inode, transfer_to); 2099 out_put: 2100 dqput_all(transfer_to); 2101 return ret; 2102 } 2103 EXPORT_SYMBOL(dquot_transfer); 2104 2105 /* 2106 * Write info of quota file to disk 2107 */ 2108 int dquot_commit_info(struct super_block *sb, int type) 2109 { 2110 struct quota_info *dqopt = sb_dqopt(sb); 2111 2112 return dqopt->ops[type]->write_file_info(sb, type); 2113 } 2114 EXPORT_SYMBOL(dquot_commit_info); 2115 2116 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2117 { 2118 struct quota_info *dqopt = sb_dqopt(sb); 2119 2120 if (!sb_has_quota_active(sb, qid->type)) 2121 return -ESRCH; 2122 if (!dqopt->ops[qid->type]->get_next_id) 2123 return -ENOSYS; 2124 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2125 } 2126 EXPORT_SYMBOL(dquot_get_next_id); 2127 2128 /* 2129 * Definitions of diskquota operations. 2130 */ 2131 const struct dquot_operations dquot_operations = { 2132 .write_dquot = dquot_commit, 2133 .acquire_dquot = dquot_acquire, 2134 .release_dquot = dquot_release, 2135 .mark_dirty = dquot_mark_dquot_dirty, 2136 .write_info = dquot_commit_info, 2137 .alloc_dquot = dquot_alloc, 2138 .destroy_dquot = dquot_destroy, 2139 .get_next_id = dquot_get_next_id, 2140 }; 2141 EXPORT_SYMBOL(dquot_operations); 2142 2143 /* 2144 * Generic helper for ->open on filesystems supporting disk quotas. 2145 */ 2146 int dquot_file_open(struct inode *inode, struct file *file) 2147 { 2148 int error; 2149 2150 error = generic_file_open(inode, file); 2151 if (!error && (file->f_mode & FMODE_WRITE)) 2152 error = dquot_initialize(inode); 2153 return error; 2154 } 2155 EXPORT_SYMBOL(dquot_file_open); 2156 2157 /* 2158 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2159 */ 2160 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2161 { 2162 int cnt, ret = 0; 2163 struct quota_info *dqopt = sb_dqopt(sb); 2164 struct inode *toputinode[MAXQUOTAS]; 2165 2166 /* s_umount should be held in exclusive mode */ 2167 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2168 up_read(&sb->s_umount); 2169 2170 /* Cannot turn off usage accounting without turning off limits, or 2171 * suspend quotas and simultaneously turn quotas off. */ 2172 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2173 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2174 DQUOT_USAGE_ENABLED))) 2175 return -EINVAL; 2176 2177 /* 2178 * Skip everything if there's nothing to do. We have to do this because 2179 * sometimes we are called when fill_super() failed and calling 2180 * sync_fs() in such cases does no good. 2181 */ 2182 if (!sb_any_quota_loaded(sb)) 2183 return 0; 2184 2185 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2186 toputinode[cnt] = NULL; 2187 if (type != -1 && cnt != type) 2188 continue; 2189 if (!sb_has_quota_loaded(sb, cnt)) 2190 continue; 2191 2192 if (flags & DQUOT_SUSPENDED) { 2193 spin_lock(&dq_state_lock); 2194 dqopt->flags |= 2195 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2196 spin_unlock(&dq_state_lock); 2197 } else { 2198 spin_lock(&dq_state_lock); 2199 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2200 /* Turning off suspended quotas? */ 2201 if (!sb_has_quota_loaded(sb, cnt) && 2202 sb_has_quota_suspended(sb, cnt)) { 2203 dqopt->flags &= ~dquot_state_flag( 2204 DQUOT_SUSPENDED, cnt); 2205 spin_unlock(&dq_state_lock); 2206 iput(dqopt->files[cnt]); 2207 dqopt->files[cnt] = NULL; 2208 continue; 2209 } 2210 spin_unlock(&dq_state_lock); 2211 } 2212 2213 /* We still have to keep quota loaded? */ 2214 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2215 continue; 2216 2217 /* Note: these are blocking operations */ 2218 drop_dquot_ref(sb, cnt); 2219 invalidate_dquots(sb, cnt); 2220 /* 2221 * Now all dquots should be invalidated, all writes done so we 2222 * should be only users of the info. No locks needed. 2223 */ 2224 if (info_dirty(&dqopt->info[cnt])) 2225 sb->dq_op->write_info(sb, cnt); 2226 if (dqopt->ops[cnt]->free_file_info) 2227 dqopt->ops[cnt]->free_file_info(sb, cnt); 2228 put_quota_format(dqopt->info[cnt].dqi_format); 2229 2230 toputinode[cnt] = dqopt->files[cnt]; 2231 if (!sb_has_quota_loaded(sb, cnt)) 2232 dqopt->files[cnt] = NULL; 2233 dqopt->info[cnt].dqi_flags = 0; 2234 dqopt->info[cnt].dqi_igrace = 0; 2235 dqopt->info[cnt].dqi_bgrace = 0; 2236 dqopt->ops[cnt] = NULL; 2237 } 2238 2239 /* Skip syncing and setting flags if quota files are hidden */ 2240 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2241 goto put_inodes; 2242 2243 /* Sync the superblock so that buffers with quota data are written to 2244 * disk (and so userspace sees correct data afterwards). */ 2245 if (sb->s_op->sync_fs) 2246 sb->s_op->sync_fs(sb, 1); 2247 sync_blockdev(sb->s_bdev); 2248 /* Now the quota files are just ordinary files and we can set the 2249 * inode flags back. Moreover we discard the pagecache so that 2250 * userspace sees the writes we did bypassing the pagecache. We 2251 * must also discard the blockdev buffers so that we see the 2252 * changes done by userspace on the next quotaon() */ 2253 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2254 /* This can happen when suspending quotas on remount-ro... */ 2255 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { 2256 inode_lock(toputinode[cnt]); 2257 toputinode[cnt]->i_flags &= ~S_NOQUOTA; 2258 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 2259 inode_unlock(toputinode[cnt]); 2260 mark_inode_dirty_sync(toputinode[cnt]); 2261 } 2262 if (sb->s_bdev) 2263 invalidate_bdev(sb->s_bdev); 2264 put_inodes: 2265 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2266 if (toputinode[cnt]) { 2267 /* On remount RO, we keep the inode pointer so that we 2268 * can reenable quota on the subsequent remount RW. We 2269 * have to check 'flags' variable and not use sb_has_ 2270 * function because another quotaon / quotaoff could 2271 * change global state before we got here. We refuse 2272 * to suspend quotas when there is pending delete on 2273 * the quota file... */ 2274 if (!(flags & DQUOT_SUSPENDED)) 2275 iput(toputinode[cnt]); 2276 else if (!toputinode[cnt]->i_nlink) 2277 ret = -EBUSY; 2278 } 2279 return ret; 2280 } 2281 EXPORT_SYMBOL(dquot_disable); 2282 2283 int dquot_quota_off(struct super_block *sb, int type) 2284 { 2285 return dquot_disable(sb, type, 2286 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2287 } 2288 EXPORT_SYMBOL(dquot_quota_off); 2289 2290 /* 2291 * Turn quotas on on a device 2292 */ 2293 2294 /* 2295 * Helper function to turn quotas on when we already have the inode of 2296 * quota file and no quota information is loaded. 2297 */ 2298 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2299 unsigned int flags) 2300 { 2301 struct quota_format_type *fmt = find_quota_format(format_id); 2302 struct super_block *sb = inode->i_sb; 2303 struct quota_info *dqopt = sb_dqopt(sb); 2304 int error; 2305 2306 if (!fmt) 2307 return -ESRCH; 2308 if (!S_ISREG(inode->i_mode)) { 2309 error = -EACCES; 2310 goto out_fmt; 2311 } 2312 if (IS_RDONLY(inode)) { 2313 error = -EROFS; 2314 goto out_fmt; 2315 } 2316 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2317 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2318 error = -EINVAL; 2319 goto out_fmt; 2320 } 2321 /* Filesystems outside of init_user_ns not yet supported */ 2322 if (sb->s_user_ns != &init_user_ns) { 2323 error = -EINVAL; 2324 goto out_fmt; 2325 } 2326 /* Usage always has to be set... */ 2327 if (!(flags & DQUOT_USAGE_ENABLED)) { 2328 error = -EINVAL; 2329 goto out_fmt; 2330 } 2331 if (sb_has_quota_loaded(sb, type)) { 2332 error = -EBUSY; 2333 goto out_fmt; 2334 } 2335 2336 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2337 /* As we bypass the pagecache we must now flush all the 2338 * dirty data and invalidate caches so that kernel sees 2339 * changes from userspace. It is not enough to just flush 2340 * the quota file since if blocksize < pagesize, invalidation 2341 * of the cache could fail because of other unrelated dirty 2342 * data */ 2343 sync_filesystem(sb); 2344 invalidate_bdev(sb->s_bdev); 2345 } 2346 2347 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2348 /* We don't want quota and atime on quota files (deadlocks 2349 * possible) Also nobody should write to the file - we use 2350 * special IO operations which ignore the immutable bit. */ 2351 inode_lock(inode); 2352 inode->i_flags |= S_NOQUOTA; 2353 inode_unlock(inode); 2354 /* 2355 * When S_NOQUOTA is set, remove dquot references as no more 2356 * references can be added 2357 */ 2358 __dquot_drop(inode); 2359 } 2360 2361 error = -EIO; 2362 dqopt->files[type] = igrab(inode); 2363 if (!dqopt->files[type]) 2364 goto out_file_flags; 2365 error = -EINVAL; 2366 if (!fmt->qf_ops->check_quota_file(sb, type)) 2367 goto out_file_init; 2368 2369 dqopt->ops[type] = fmt->qf_ops; 2370 dqopt->info[type].dqi_format = fmt; 2371 dqopt->info[type].dqi_fmt_id = format_id; 2372 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2373 error = dqopt->ops[type]->read_file_info(sb, type); 2374 if (error < 0) 2375 goto out_file_init; 2376 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2377 spin_lock(&dq_data_lock); 2378 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2379 spin_unlock(&dq_data_lock); 2380 } 2381 spin_lock(&dq_state_lock); 2382 dqopt->flags |= dquot_state_flag(flags, type); 2383 spin_unlock(&dq_state_lock); 2384 2385 error = add_dquot_ref(sb, type); 2386 if (error) 2387 dquot_disable(sb, type, flags); 2388 2389 return error; 2390 out_file_init: 2391 dqopt->files[type] = NULL; 2392 iput(inode); 2393 out_file_flags: 2394 inode_lock(inode); 2395 inode->i_flags &= ~S_NOQUOTA; 2396 inode_unlock(inode); 2397 out_fmt: 2398 put_quota_format(fmt); 2399 2400 return error; 2401 } 2402 2403 /* Reenable quotas on remount RW */ 2404 int dquot_resume(struct super_block *sb, int type) 2405 { 2406 struct quota_info *dqopt = sb_dqopt(sb); 2407 struct inode *inode; 2408 int ret = 0, cnt; 2409 unsigned int flags; 2410 2411 /* s_umount should be held in exclusive mode */ 2412 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2413 up_read(&sb->s_umount); 2414 2415 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2416 if (type != -1 && cnt != type) 2417 continue; 2418 if (!sb_has_quota_suspended(sb, cnt)) 2419 continue; 2420 2421 inode = dqopt->files[cnt]; 2422 dqopt->files[cnt] = NULL; 2423 spin_lock(&dq_state_lock); 2424 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2425 DQUOT_LIMITS_ENABLED, 2426 cnt); 2427 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2428 spin_unlock(&dq_state_lock); 2429 2430 flags = dquot_generic_flag(flags, cnt); 2431 ret = vfs_load_quota_inode(inode, cnt, 2432 dqopt->info[cnt].dqi_fmt_id, flags); 2433 iput(inode); 2434 } 2435 2436 return ret; 2437 } 2438 EXPORT_SYMBOL(dquot_resume); 2439 2440 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2441 const struct path *path) 2442 { 2443 int error = security_quota_on(path->dentry); 2444 if (error) 2445 return error; 2446 /* Quota file not on the same filesystem? */ 2447 if (path->dentry->d_sb != sb) 2448 error = -EXDEV; 2449 else 2450 error = vfs_load_quota_inode(d_inode(path->dentry), type, 2451 format_id, DQUOT_USAGE_ENABLED | 2452 DQUOT_LIMITS_ENABLED); 2453 return error; 2454 } 2455 EXPORT_SYMBOL(dquot_quota_on); 2456 2457 /* 2458 * More powerful function for turning on quotas allowing setting 2459 * of individual quota flags 2460 */ 2461 int dquot_enable(struct inode *inode, int type, int format_id, 2462 unsigned int flags) 2463 { 2464 struct super_block *sb = inode->i_sb; 2465 2466 /* Just unsuspend quotas? */ 2467 BUG_ON(flags & DQUOT_SUSPENDED); 2468 /* s_umount should be held in exclusive mode */ 2469 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2470 up_read(&sb->s_umount); 2471 2472 if (!flags) 2473 return 0; 2474 /* Just updating flags needed? */ 2475 if (sb_has_quota_loaded(sb, type)) { 2476 if (flags & DQUOT_USAGE_ENABLED && 2477 sb_has_quota_usage_enabled(sb, type)) 2478 return -EBUSY; 2479 if (flags & DQUOT_LIMITS_ENABLED && 2480 sb_has_quota_limits_enabled(sb, type)) 2481 return -EBUSY; 2482 spin_lock(&dq_state_lock); 2483 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2484 spin_unlock(&dq_state_lock); 2485 return 0; 2486 } 2487 2488 return vfs_load_quota_inode(inode, type, format_id, flags); 2489 } 2490 EXPORT_SYMBOL(dquot_enable); 2491 2492 /* 2493 * This function is used when filesystem needs to initialize quotas 2494 * during mount time. 2495 */ 2496 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2497 int format_id, int type) 2498 { 2499 struct dentry *dentry; 2500 int error; 2501 2502 dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2503 if (IS_ERR(dentry)) 2504 return PTR_ERR(dentry); 2505 2506 if (d_really_is_negative(dentry)) { 2507 error = -ENOENT; 2508 goto out; 2509 } 2510 2511 error = security_quota_on(dentry); 2512 if (!error) 2513 error = vfs_load_quota_inode(d_inode(dentry), type, format_id, 2514 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2515 2516 out: 2517 dput(dentry); 2518 return error; 2519 } 2520 EXPORT_SYMBOL(dquot_quota_on_mount); 2521 2522 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2523 { 2524 int ret; 2525 int type; 2526 struct quota_info *dqopt = sb_dqopt(sb); 2527 2528 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2529 return -ENOSYS; 2530 /* Accounting cannot be turned on while fs is mounted */ 2531 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2532 if (!flags) 2533 return -EINVAL; 2534 for (type = 0; type < MAXQUOTAS; type++) { 2535 if (!(flags & qtype_enforce_flag(type))) 2536 continue; 2537 /* Can't enforce without accounting */ 2538 if (!sb_has_quota_usage_enabled(sb, type)) 2539 return -EINVAL; 2540 ret = dquot_enable(dqopt->files[type], type, 2541 dqopt->info[type].dqi_fmt_id, 2542 DQUOT_LIMITS_ENABLED); 2543 if (ret < 0) 2544 goto out_err; 2545 } 2546 return 0; 2547 out_err: 2548 /* Backout enforcement enablement we already did */ 2549 for (type--; type >= 0; type--) { 2550 if (flags & qtype_enforce_flag(type)) 2551 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2552 } 2553 /* Error code translation for better compatibility with XFS */ 2554 if (ret == -EBUSY) 2555 ret = -EEXIST; 2556 return ret; 2557 } 2558 2559 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2560 { 2561 int ret; 2562 int type; 2563 struct quota_info *dqopt = sb_dqopt(sb); 2564 2565 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2566 return -ENOSYS; 2567 /* 2568 * We don't support turning off accounting via quotactl. In principle 2569 * quota infrastructure can do this but filesystems don't expect 2570 * userspace to be able to do it. 2571 */ 2572 if (flags & 2573 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2574 return -EOPNOTSUPP; 2575 2576 /* Filter out limits not enabled */ 2577 for (type = 0; type < MAXQUOTAS; type++) 2578 if (!sb_has_quota_limits_enabled(sb, type)) 2579 flags &= ~qtype_enforce_flag(type); 2580 /* Nothing left? */ 2581 if (!flags) 2582 return -EEXIST; 2583 for (type = 0; type < MAXQUOTAS; type++) { 2584 if (flags & qtype_enforce_flag(type)) { 2585 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2586 if (ret < 0) 2587 goto out_err; 2588 } 2589 } 2590 return 0; 2591 out_err: 2592 /* Backout enforcement disabling we already did */ 2593 for (type--; type >= 0; type--) { 2594 if (flags & qtype_enforce_flag(type)) 2595 dquot_enable(dqopt->files[type], type, 2596 dqopt->info[type].dqi_fmt_id, 2597 DQUOT_LIMITS_ENABLED); 2598 } 2599 return ret; 2600 } 2601 2602 /* Generic routine for getting common part of quota structure */ 2603 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2604 { 2605 struct mem_dqblk *dm = &dquot->dq_dqb; 2606 2607 memset(di, 0, sizeof(*di)); 2608 spin_lock(&dquot->dq_dqb_lock); 2609 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2610 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2611 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2612 di->d_ino_softlimit = dm->dqb_isoftlimit; 2613 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2614 di->d_ino_count = dm->dqb_curinodes; 2615 di->d_spc_timer = dm->dqb_btime; 2616 di->d_ino_timer = dm->dqb_itime; 2617 spin_unlock(&dquot->dq_dqb_lock); 2618 } 2619 2620 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2621 struct qc_dqblk *di) 2622 { 2623 struct dquot *dquot; 2624 2625 dquot = dqget(sb, qid); 2626 if (IS_ERR(dquot)) 2627 return PTR_ERR(dquot); 2628 do_get_dqblk(dquot, di); 2629 dqput(dquot); 2630 2631 return 0; 2632 } 2633 EXPORT_SYMBOL(dquot_get_dqblk); 2634 2635 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2636 struct qc_dqblk *di) 2637 { 2638 struct dquot *dquot; 2639 int err; 2640 2641 if (!sb->dq_op->get_next_id) 2642 return -ENOSYS; 2643 err = sb->dq_op->get_next_id(sb, qid); 2644 if (err < 0) 2645 return err; 2646 dquot = dqget(sb, *qid); 2647 if (IS_ERR(dquot)) 2648 return PTR_ERR(dquot); 2649 do_get_dqblk(dquot, di); 2650 dqput(dquot); 2651 2652 return 0; 2653 } 2654 EXPORT_SYMBOL(dquot_get_next_dqblk); 2655 2656 #define VFS_QC_MASK \ 2657 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2658 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2659 QC_SPC_TIMER | QC_INO_TIMER) 2660 2661 /* Generic routine for setting common part of quota structure */ 2662 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2663 { 2664 struct mem_dqblk *dm = &dquot->dq_dqb; 2665 int check_blim = 0, check_ilim = 0; 2666 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2667 2668 if (di->d_fieldmask & ~VFS_QC_MASK) 2669 return -EINVAL; 2670 2671 if (((di->d_fieldmask & QC_SPC_SOFT) && 2672 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2673 ((di->d_fieldmask & QC_SPC_HARD) && 2674 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2675 ((di->d_fieldmask & QC_INO_SOFT) && 2676 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2677 ((di->d_fieldmask & QC_INO_HARD) && 2678 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2679 return -ERANGE; 2680 2681 spin_lock(&dquot->dq_dqb_lock); 2682 if (di->d_fieldmask & QC_SPACE) { 2683 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2684 check_blim = 1; 2685 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2686 } 2687 2688 if (di->d_fieldmask & QC_SPC_SOFT) 2689 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2690 if (di->d_fieldmask & QC_SPC_HARD) 2691 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2692 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2693 check_blim = 1; 2694 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2695 } 2696 2697 if (di->d_fieldmask & QC_INO_COUNT) { 2698 dm->dqb_curinodes = di->d_ino_count; 2699 check_ilim = 1; 2700 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2701 } 2702 2703 if (di->d_fieldmask & QC_INO_SOFT) 2704 dm->dqb_isoftlimit = di->d_ino_softlimit; 2705 if (di->d_fieldmask & QC_INO_HARD) 2706 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2707 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2708 check_ilim = 1; 2709 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2710 } 2711 2712 if (di->d_fieldmask & QC_SPC_TIMER) { 2713 dm->dqb_btime = di->d_spc_timer; 2714 check_blim = 1; 2715 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2716 } 2717 2718 if (di->d_fieldmask & QC_INO_TIMER) { 2719 dm->dqb_itime = di->d_ino_timer; 2720 check_ilim = 1; 2721 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2722 } 2723 2724 if (check_blim) { 2725 if (!dm->dqb_bsoftlimit || 2726 dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) { 2727 dm->dqb_btime = 0; 2728 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2729 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2730 /* Set grace only if user hasn't provided his own... */ 2731 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2732 } 2733 if (check_ilim) { 2734 if (!dm->dqb_isoftlimit || 2735 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2736 dm->dqb_itime = 0; 2737 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2738 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2739 /* Set grace only if user hasn't provided his own... */ 2740 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2741 } 2742 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2743 dm->dqb_isoftlimit) 2744 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2745 else 2746 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2747 spin_unlock(&dquot->dq_dqb_lock); 2748 mark_dquot_dirty(dquot); 2749 2750 return 0; 2751 } 2752 2753 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2754 struct qc_dqblk *di) 2755 { 2756 struct dquot *dquot; 2757 int rc; 2758 2759 dquot = dqget(sb, qid); 2760 if (IS_ERR(dquot)) { 2761 rc = PTR_ERR(dquot); 2762 goto out; 2763 } 2764 rc = do_set_dqblk(dquot, di); 2765 dqput(dquot); 2766 out: 2767 return rc; 2768 } 2769 EXPORT_SYMBOL(dquot_set_dqblk); 2770 2771 /* Generic routine for getting common part of quota file information */ 2772 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2773 { 2774 struct mem_dqinfo *mi; 2775 struct qc_type_state *tstate; 2776 struct quota_info *dqopt = sb_dqopt(sb); 2777 int type; 2778 2779 memset(state, 0, sizeof(*state)); 2780 for (type = 0; type < MAXQUOTAS; type++) { 2781 if (!sb_has_quota_active(sb, type)) 2782 continue; 2783 tstate = state->s_state + type; 2784 mi = sb_dqopt(sb)->info + type; 2785 tstate->flags = QCI_ACCT_ENABLED; 2786 spin_lock(&dq_data_lock); 2787 if (mi->dqi_flags & DQF_SYS_FILE) 2788 tstate->flags |= QCI_SYSFILE; 2789 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2790 tstate->flags |= QCI_ROOT_SQUASH; 2791 if (sb_has_quota_limits_enabled(sb, type)) 2792 tstate->flags |= QCI_LIMITS_ENFORCED; 2793 tstate->spc_timelimit = mi->dqi_bgrace; 2794 tstate->ino_timelimit = mi->dqi_igrace; 2795 tstate->ino = dqopt->files[type]->i_ino; 2796 tstate->blocks = dqopt->files[type]->i_blocks; 2797 tstate->nextents = 1; /* We don't know... */ 2798 spin_unlock(&dq_data_lock); 2799 } 2800 return 0; 2801 } 2802 EXPORT_SYMBOL(dquot_get_state); 2803 2804 /* Generic routine for setting common part of quota file information */ 2805 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2806 { 2807 struct mem_dqinfo *mi; 2808 int err = 0; 2809 2810 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2811 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2812 return -EINVAL; 2813 if (!sb_has_quota_active(sb, type)) 2814 return -ESRCH; 2815 mi = sb_dqopt(sb)->info + type; 2816 if (ii->i_fieldmask & QC_FLAGS) { 2817 if ((ii->i_flags & QCI_ROOT_SQUASH && 2818 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2819 return -EINVAL; 2820 } 2821 spin_lock(&dq_data_lock); 2822 if (ii->i_fieldmask & QC_SPC_TIMER) 2823 mi->dqi_bgrace = ii->i_spc_timelimit; 2824 if (ii->i_fieldmask & QC_INO_TIMER) 2825 mi->dqi_igrace = ii->i_ino_timelimit; 2826 if (ii->i_fieldmask & QC_FLAGS) { 2827 if (ii->i_flags & QCI_ROOT_SQUASH) 2828 mi->dqi_flags |= DQF_ROOT_SQUASH; 2829 else 2830 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2831 } 2832 spin_unlock(&dq_data_lock); 2833 mark_info_dirty(sb, type); 2834 /* Force write to disk */ 2835 sb->dq_op->write_info(sb, type); 2836 return err; 2837 } 2838 EXPORT_SYMBOL(dquot_set_dqinfo); 2839 2840 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2841 .quota_enable = dquot_quota_enable, 2842 .quota_disable = dquot_quota_disable, 2843 .quota_sync = dquot_quota_sync, 2844 .get_state = dquot_get_state, 2845 .set_info = dquot_set_dqinfo, 2846 .get_dqblk = dquot_get_dqblk, 2847 .get_nextdqblk = dquot_get_next_dqblk, 2848 .set_dqblk = dquot_set_dqblk 2849 }; 2850 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2851 2852 static int do_proc_dqstats(struct ctl_table *table, int write, 2853 void __user *buffer, size_t *lenp, loff_t *ppos) 2854 { 2855 unsigned int type = (int *)table->data - dqstats.stat; 2856 2857 /* Update global table */ 2858 dqstats.stat[type] = 2859 percpu_counter_sum_positive(&dqstats.counter[type]); 2860 return proc_dointvec(table, write, buffer, lenp, ppos); 2861 } 2862 2863 static struct ctl_table fs_dqstats_table[] = { 2864 { 2865 .procname = "lookups", 2866 .data = &dqstats.stat[DQST_LOOKUPS], 2867 .maxlen = sizeof(int), 2868 .mode = 0444, 2869 .proc_handler = do_proc_dqstats, 2870 }, 2871 { 2872 .procname = "drops", 2873 .data = &dqstats.stat[DQST_DROPS], 2874 .maxlen = sizeof(int), 2875 .mode = 0444, 2876 .proc_handler = do_proc_dqstats, 2877 }, 2878 { 2879 .procname = "reads", 2880 .data = &dqstats.stat[DQST_READS], 2881 .maxlen = sizeof(int), 2882 .mode = 0444, 2883 .proc_handler = do_proc_dqstats, 2884 }, 2885 { 2886 .procname = "writes", 2887 .data = &dqstats.stat[DQST_WRITES], 2888 .maxlen = sizeof(int), 2889 .mode = 0444, 2890 .proc_handler = do_proc_dqstats, 2891 }, 2892 { 2893 .procname = "cache_hits", 2894 .data = &dqstats.stat[DQST_CACHE_HITS], 2895 .maxlen = sizeof(int), 2896 .mode = 0444, 2897 .proc_handler = do_proc_dqstats, 2898 }, 2899 { 2900 .procname = "allocated_dquots", 2901 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2902 .maxlen = sizeof(int), 2903 .mode = 0444, 2904 .proc_handler = do_proc_dqstats, 2905 }, 2906 { 2907 .procname = "free_dquots", 2908 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2909 .maxlen = sizeof(int), 2910 .mode = 0444, 2911 .proc_handler = do_proc_dqstats, 2912 }, 2913 { 2914 .procname = "syncs", 2915 .data = &dqstats.stat[DQST_SYNCS], 2916 .maxlen = sizeof(int), 2917 .mode = 0444, 2918 .proc_handler = do_proc_dqstats, 2919 }, 2920 #ifdef CONFIG_PRINT_QUOTA_WARNING 2921 { 2922 .procname = "warnings", 2923 .data = &flag_print_warnings, 2924 .maxlen = sizeof(int), 2925 .mode = 0644, 2926 .proc_handler = proc_dointvec, 2927 }, 2928 #endif 2929 { }, 2930 }; 2931 2932 static struct ctl_table fs_table[] = { 2933 { 2934 .procname = "quota", 2935 .mode = 0555, 2936 .child = fs_dqstats_table, 2937 }, 2938 { }, 2939 }; 2940 2941 static struct ctl_table sys_table[] = { 2942 { 2943 .procname = "fs", 2944 .mode = 0555, 2945 .child = fs_table, 2946 }, 2947 { }, 2948 }; 2949 2950 static int __init dquot_init(void) 2951 { 2952 int i, ret; 2953 unsigned long nr_hash, order; 2954 2955 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2956 2957 register_sysctl_table(sys_table); 2958 2959 dquot_cachep = kmem_cache_create("dquot", 2960 sizeof(struct dquot), sizeof(unsigned long) * 4, 2961 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2962 SLAB_MEM_SPREAD|SLAB_PANIC), 2963 NULL); 2964 2965 order = 0; 2966 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2967 if (!dquot_hash) 2968 panic("Cannot create dquot hash table"); 2969 2970 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2971 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2972 if (ret) 2973 panic("Cannot create dquot stat counters"); 2974 } 2975 2976 /* Find power-of-two hlist_heads which can fit into allocation */ 2977 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2978 dq_hash_bits = 0; 2979 do { 2980 dq_hash_bits++; 2981 } while (nr_hash >> dq_hash_bits); 2982 dq_hash_bits--; 2983 2984 nr_hash = 1UL << dq_hash_bits; 2985 dq_hash_mask = nr_hash - 1; 2986 for (i = 0; i < nr_hash; i++) 2987 INIT_HLIST_HEAD(dquot_hash + i); 2988 2989 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2990 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2991 2992 if (register_shrinker(&dqcache_shrinker)) 2993 panic("Cannot register dquot shrinker"); 2994 2995 return 0; 2996 } 2997 fs_initcall(dquot_init); 2998