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 four lists for dquot management: the inuse_list, 227 * free_dquots, dqi_dirty_list, and dquot_hash[] array. A single dquot 228 * structure may be on some of those 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 * Dirty dquots are added to the dqi_dirty_list of quota_info when mark 240 * dirtied, and this list is searched when writing dirty dquots back to 241 * quota file. Note that some filesystems do dirty dquot tracking on their 242 * own (e.g. in a journal) and thus don't use dqi_dirty_list. 243 * 244 * Dquots with a specific identity (device, type and id) are placed on 245 * one of the dquot_hash[] hash chains. The provides an efficient search 246 * mechanism to locate a specific dquot. 247 */ 248 249 static LIST_HEAD(inuse_list); 250 static LIST_HEAD(free_dquots); 251 static unsigned int dq_hash_bits, dq_hash_mask; 252 static struct hlist_head *dquot_hash; 253 254 struct dqstats dqstats; 255 EXPORT_SYMBOL(dqstats); 256 257 static qsize_t inode_get_rsv_space(struct inode *inode); 258 static qsize_t __inode_get_rsv_space(struct inode *inode); 259 static int __dquot_initialize(struct inode *inode, int type); 260 261 static inline unsigned int 262 hashfn(const struct super_block *sb, struct kqid qid) 263 { 264 unsigned int id = from_kqid(&init_user_ns, qid); 265 int type = qid.type; 266 unsigned long tmp; 267 268 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 269 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 270 } 271 272 /* 273 * Following list functions expect dq_list_lock to be held 274 */ 275 static inline void insert_dquot_hash(struct dquot *dquot) 276 { 277 struct hlist_head *head; 278 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 279 hlist_add_head(&dquot->dq_hash, head); 280 } 281 282 static inline void remove_dquot_hash(struct dquot *dquot) 283 { 284 hlist_del_init(&dquot->dq_hash); 285 } 286 287 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 288 struct kqid qid) 289 { 290 struct hlist_node *node; 291 struct dquot *dquot; 292 293 hlist_for_each (node, dquot_hash+hashent) { 294 dquot = hlist_entry(node, struct dquot, dq_hash); 295 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 296 return dquot; 297 } 298 return NULL; 299 } 300 301 /* Add a dquot to the tail of the free list */ 302 static inline void put_dquot_last(struct dquot *dquot) 303 { 304 list_add_tail(&dquot->dq_free, &free_dquots); 305 dqstats_inc(DQST_FREE_DQUOTS); 306 } 307 308 static inline void remove_free_dquot(struct dquot *dquot) 309 { 310 if (list_empty(&dquot->dq_free)) 311 return; 312 list_del_init(&dquot->dq_free); 313 dqstats_dec(DQST_FREE_DQUOTS); 314 } 315 316 static inline void put_inuse(struct dquot *dquot) 317 { 318 /* We add to the back of inuse list so we don't have to restart 319 * when traversing this list and we block */ 320 list_add_tail(&dquot->dq_inuse, &inuse_list); 321 dqstats_inc(DQST_ALLOC_DQUOTS); 322 } 323 324 static inline void remove_inuse(struct dquot *dquot) 325 { 326 dqstats_dec(DQST_ALLOC_DQUOTS); 327 list_del(&dquot->dq_inuse); 328 } 329 /* 330 * End of list functions needing dq_list_lock 331 */ 332 333 static void wait_on_dquot(struct dquot *dquot) 334 { 335 mutex_lock(&dquot->dq_lock); 336 mutex_unlock(&dquot->dq_lock); 337 } 338 339 static inline int dquot_dirty(struct dquot *dquot) 340 { 341 return test_bit(DQ_MOD_B, &dquot->dq_flags); 342 } 343 344 static inline int mark_dquot_dirty(struct dquot *dquot) 345 { 346 return dquot->dq_sb->dq_op->mark_dirty(dquot); 347 } 348 349 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 350 int dquot_mark_dquot_dirty(struct dquot *dquot) 351 { 352 int ret = 1; 353 354 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 355 return 0; 356 357 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 358 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 359 360 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 361 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 362 return 1; 363 364 spin_lock(&dq_list_lock); 365 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 366 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 367 info[dquot->dq_id.type].dqi_dirty_list); 368 ret = 0; 369 } 370 spin_unlock(&dq_list_lock); 371 return ret; 372 } 373 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 374 375 /* Dirtify all the dquots - this can block when journalling */ 376 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 377 { 378 int ret, err, cnt; 379 380 ret = err = 0; 381 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 382 if (dquot[cnt]) 383 /* Even in case of error we have to continue */ 384 ret = mark_dquot_dirty(dquot[cnt]); 385 if (!err) 386 err = ret; 387 } 388 return err; 389 } 390 391 static inline void dqput_all(struct dquot **dquot) 392 { 393 unsigned int cnt; 394 395 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 396 dqput(dquot[cnt]); 397 } 398 399 static inline int clear_dquot_dirty(struct dquot *dquot) 400 { 401 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 402 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 403 404 spin_lock(&dq_list_lock); 405 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 406 spin_unlock(&dq_list_lock); 407 return 0; 408 } 409 list_del_init(&dquot->dq_dirty); 410 spin_unlock(&dq_list_lock); 411 return 1; 412 } 413 414 void mark_info_dirty(struct super_block *sb, int type) 415 { 416 spin_lock(&dq_data_lock); 417 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 418 spin_unlock(&dq_data_lock); 419 } 420 EXPORT_SYMBOL(mark_info_dirty); 421 422 /* 423 * Read dquot from disk and alloc space for it 424 */ 425 426 int dquot_acquire(struct dquot *dquot) 427 { 428 int ret = 0, ret2 = 0; 429 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 430 431 mutex_lock(&dquot->dq_lock); 432 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { 433 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 434 if (ret < 0) 435 goto out_iolock; 436 } 437 /* Make sure flags update is visible after dquot has been filled */ 438 smp_mb__before_atomic(); 439 set_bit(DQ_READ_B, &dquot->dq_flags); 440 /* Instantiate dquot if needed */ 441 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 442 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 443 /* Write the info if needed */ 444 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 445 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 446 dquot->dq_sb, dquot->dq_id.type); 447 } 448 if (ret < 0) 449 goto out_iolock; 450 if (ret2 < 0) { 451 ret = ret2; 452 goto out_iolock; 453 } 454 } 455 /* 456 * Make sure flags update is visible after on-disk struct has been 457 * allocated. Paired with smp_rmb() in dqget(). 458 */ 459 smp_mb__before_atomic(); 460 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 461 out_iolock: 462 mutex_unlock(&dquot->dq_lock); 463 return ret; 464 } 465 EXPORT_SYMBOL(dquot_acquire); 466 467 /* 468 * Write dquot to disk 469 */ 470 int dquot_commit(struct dquot *dquot) 471 { 472 int ret = 0; 473 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 474 475 mutex_lock(&dquot->dq_lock); 476 if (!clear_dquot_dirty(dquot)) 477 goto out_lock; 478 /* Inactive dquot can be only if there was error during read/init 479 * => we have better not writing it */ 480 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 481 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 482 else 483 ret = -EIO; 484 out_lock: 485 mutex_unlock(&dquot->dq_lock); 486 return ret; 487 } 488 EXPORT_SYMBOL(dquot_commit); 489 490 /* 491 * Release dquot 492 */ 493 int dquot_release(struct dquot *dquot) 494 { 495 int ret = 0, ret2 = 0; 496 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 497 498 mutex_lock(&dquot->dq_lock); 499 /* Check whether we are not racing with some other dqget() */ 500 if (atomic_read(&dquot->dq_count) > 1) 501 goto out_dqlock; 502 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 503 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 504 /* Write the info */ 505 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 506 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 507 dquot->dq_sb, dquot->dq_id.type); 508 } 509 if (ret >= 0) 510 ret = ret2; 511 } 512 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 513 out_dqlock: 514 mutex_unlock(&dquot->dq_lock); 515 return ret; 516 } 517 EXPORT_SYMBOL(dquot_release); 518 519 void dquot_destroy(struct dquot *dquot) 520 { 521 kmem_cache_free(dquot_cachep, dquot); 522 } 523 EXPORT_SYMBOL(dquot_destroy); 524 525 static inline void do_destroy_dquot(struct dquot *dquot) 526 { 527 dquot->dq_sb->dq_op->destroy_dquot(dquot); 528 } 529 530 /* Invalidate all dquots on the list. Note that this function is called after 531 * quota is disabled and pointers from inodes removed so there cannot be new 532 * quota users. There can still be some users of quotas due to inodes being 533 * just deleted or pruned by prune_icache() (those are not attached to any 534 * list) or parallel quotactl call. We have to wait for such users. 535 */ 536 static void invalidate_dquots(struct super_block *sb, int type) 537 { 538 struct dquot *dquot, *tmp; 539 540 restart: 541 spin_lock(&dq_list_lock); 542 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 543 if (dquot->dq_sb != sb) 544 continue; 545 if (dquot->dq_id.type != type) 546 continue; 547 /* Wait for dquot users */ 548 if (atomic_read(&dquot->dq_count)) { 549 dqgrab(dquot); 550 spin_unlock(&dq_list_lock); 551 /* 552 * Once dqput() wakes us up, we know it's time to free 553 * the dquot. 554 * IMPORTANT: we rely on the fact that there is always 555 * at most one process waiting for dquot to free. 556 * Otherwise dq_count would be > 1 and we would never 557 * wake up. 558 */ 559 wait_event(dquot_ref_wq, 560 atomic_read(&dquot->dq_count) == 1); 561 dqput(dquot); 562 /* At this moment dquot() need not exist (it could be 563 * reclaimed by prune_dqcache(). Hence we must 564 * restart. */ 565 goto restart; 566 } 567 /* 568 * Quota now has no users and it has been written on last 569 * dqput() 570 */ 571 remove_dquot_hash(dquot); 572 remove_free_dquot(dquot); 573 remove_inuse(dquot); 574 do_destroy_dquot(dquot); 575 } 576 spin_unlock(&dq_list_lock); 577 } 578 579 /* Call callback for every active dquot on given filesystem */ 580 int dquot_scan_active(struct super_block *sb, 581 int (*fn)(struct dquot *dquot, unsigned long priv), 582 unsigned long priv) 583 { 584 struct dquot *dquot, *old_dquot = NULL; 585 int ret = 0; 586 587 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 588 589 spin_lock(&dq_list_lock); 590 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 591 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 592 continue; 593 if (dquot->dq_sb != sb) 594 continue; 595 /* Now we have active dquot so we can just increase use count */ 596 atomic_inc(&dquot->dq_count); 597 spin_unlock(&dq_list_lock); 598 dqstats_inc(DQST_LOOKUPS); 599 dqput(old_dquot); 600 old_dquot = dquot; 601 /* 602 * ->release_dquot() can be racing with us. Our reference 603 * protects us from new calls to it so just wait for any 604 * outstanding call and recheck the DQ_ACTIVE_B after that. 605 */ 606 wait_on_dquot(dquot); 607 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 608 ret = fn(dquot, priv); 609 if (ret < 0) 610 goto out; 611 } 612 spin_lock(&dq_list_lock); 613 /* We are safe to continue now because our dquot could not 614 * be moved out of the inuse list while we hold the reference */ 615 } 616 spin_unlock(&dq_list_lock); 617 out: 618 dqput(old_dquot); 619 return ret; 620 } 621 EXPORT_SYMBOL(dquot_scan_active); 622 623 /* Write all dquot structures to quota files */ 624 int dquot_writeback_dquots(struct super_block *sb, int type) 625 { 626 struct list_head *dirty; 627 struct dquot *dquot; 628 struct quota_info *dqopt = sb_dqopt(sb); 629 int cnt; 630 int err, ret = 0; 631 632 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 633 634 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 635 if (type != -1 && cnt != type) 636 continue; 637 if (!sb_has_quota_active(sb, cnt)) 638 continue; 639 spin_lock(&dq_list_lock); 640 dirty = &dqopt->info[cnt].dqi_dirty_list; 641 while (!list_empty(dirty)) { 642 dquot = list_first_entry(dirty, struct dquot, 643 dq_dirty); 644 645 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 646 647 /* Now we have active dquot from which someone is 648 * holding reference so we can safely just increase 649 * use count */ 650 dqgrab(dquot); 651 spin_unlock(&dq_list_lock); 652 dqstats_inc(DQST_LOOKUPS); 653 err = sb->dq_op->write_dquot(dquot); 654 if (err) { 655 /* 656 * Clear dirty bit anyway to avoid infinite 657 * loop here. 658 */ 659 clear_dquot_dirty(dquot); 660 if (!ret) 661 ret = err; 662 } 663 dqput(dquot); 664 spin_lock(&dq_list_lock); 665 } 666 spin_unlock(&dq_list_lock); 667 } 668 669 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 670 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 671 && info_dirty(&dqopt->info[cnt])) 672 sb->dq_op->write_info(sb, cnt); 673 dqstats_inc(DQST_SYNCS); 674 675 return ret; 676 } 677 EXPORT_SYMBOL(dquot_writeback_dquots); 678 679 /* Write all dquot structures to disk and make them visible from userspace */ 680 int dquot_quota_sync(struct super_block *sb, int type) 681 { 682 struct quota_info *dqopt = sb_dqopt(sb); 683 int cnt; 684 int ret; 685 686 ret = dquot_writeback_dquots(sb, type); 687 if (ret) 688 return ret; 689 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 690 return 0; 691 692 /* This is not very clever (and fast) but currently I don't know about 693 * any other simple way of getting quota data to disk and we must get 694 * them there for userspace to be visible... */ 695 if (sb->s_op->sync_fs) 696 sb->s_op->sync_fs(sb, 1); 697 sync_blockdev(sb->s_bdev); 698 699 /* 700 * Now when everything is written we can discard the pagecache so 701 * that userspace sees the changes. 702 */ 703 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 704 if (type != -1 && cnt != type) 705 continue; 706 if (!sb_has_quota_active(sb, cnt)) 707 continue; 708 inode_lock(dqopt->files[cnt]); 709 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 710 inode_unlock(dqopt->files[cnt]); 711 } 712 713 return 0; 714 } 715 EXPORT_SYMBOL(dquot_quota_sync); 716 717 static unsigned long 718 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 719 { 720 struct dquot *dquot; 721 unsigned long freed = 0; 722 723 spin_lock(&dq_list_lock); 724 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 725 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 726 remove_dquot_hash(dquot); 727 remove_free_dquot(dquot); 728 remove_inuse(dquot); 729 do_destroy_dquot(dquot); 730 sc->nr_to_scan--; 731 freed++; 732 } 733 spin_unlock(&dq_list_lock); 734 return freed; 735 } 736 737 static unsigned long 738 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 739 { 740 return vfs_pressure_ratio( 741 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 742 } 743 744 static struct shrinker dqcache_shrinker = { 745 .count_objects = dqcache_shrink_count, 746 .scan_objects = dqcache_shrink_scan, 747 .seeks = DEFAULT_SEEKS, 748 }; 749 750 /* 751 * Put reference to dquot 752 */ 753 void dqput(struct dquot *dquot) 754 { 755 int ret; 756 757 if (!dquot) 758 return; 759 #ifdef CONFIG_QUOTA_DEBUG 760 if (!atomic_read(&dquot->dq_count)) { 761 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 762 quotatypes[dquot->dq_id.type], 763 from_kqid(&init_user_ns, dquot->dq_id)); 764 BUG(); 765 } 766 #endif 767 dqstats_inc(DQST_DROPS); 768 we_slept: 769 spin_lock(&dq_list_lock); 770 if (atomic_read(&dquot->dq_count) > 1) { 771 /* We have more than one user... nothing to do */ 772 atomic_dec(&dquot->dq_count); 773 /* Releasing dquot during quotaoff phase? */ 774 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 775 atomic_read(&dquot->dq_count) == 1) 776 wake_up(&dquot_ref_wq); 777 spin_unlock(&dq_list_lock); 778 return; 779 } 780 /* Need to release dquot? */ 781 if (dquot_dirty(dquot)) { 782 spin_unlock(&dq_list_lock); 783 /* Commit dquot before releasing */ 784 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 785 if (ret < 0) { 786 quota_error(dquot->dq_sb, "Can't write quota structure" 787 " (error %d). Quota may get out of sync!", 788 ret); 789 /* 790 * We clear dirty bit anyway, so that we avoid 791 * infinite loop here 792 */ 793 clear_dquot_dirty(dquot); 794 } 795 goto we_slept; 796 } 797 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 798 spin_unlock(&dq_list_lock); 799 dquot->dq_sb->dq_op->release_dquot(dquot); 800 goto we_slept; 801 } 802 atomic_dec(&dquot->dq_count); 803 #ifdef CONFIG_QUOTA_DEBUG 804 /* sanity check */ 805 BUG_ON(!list_empty(&dquot->dq_free)); 806 #endif 807 put_dquot_last(dquot); 808 spin_unlock(&dq_list_lock); 809 } 810 EXPORT_SYMBOL(dqput); 811 812 struct dquot *dquot_alloc(struct super_block *sb, int type) 813 { 814 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 815 } 816 EXPORT_SYMBOL(dquot_alloc); 817 818 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 819 { 820 struct dquot *dquot; 821 822 dquot = sb->dq_op->alloc_dquot(sb, type); 823 if(!dquot) 824 return NULL; 825 826 mutex_init(&dquot->dq_lock); 827 INIT_LIST_HEAD(&dquot->dq_free); 828 INIT_LIST_HEAD(&dquot->dq_inuse); 829 INIT_HLIST_NODE(&dquot->dq_hash); 830 INIT_LIST_HEAD(&dquot->dq_dirty); 831 dquot->dq_sb = sb; 832 dquot->dq_id = make_kqid_invalid(type); 833 atomic_set(&dquot->dq_count, 1); 834 spin_lock_init(&dquot->dq_dqb_lock); 835 836 return dquot; 837 } 838 839 /* 840 * Get reference to dquot 841 * 842 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 843 * destroying our dquot by: 844 * a) checking for quota flags under dq_list_lock and 845 * b) getting a reference to dquot before we release dq_list_lock 846 */ 847 struct dquot *dqget(struct super_block *sb, struct kqid qid) 848 { 849 unsigned int hashent = hashfn(sb, qid); 850 struct dquot *dquot, *empty = NULL; 851 852 if (!qid_has_mapping(sb->s_user_ns, qid)) 853 return ERR_PTR(-EINVAL); 854 855 if (!sb_has_quota_active(sb, qid.type)) 856 return ERR_PTR(-ESRCH); 857 we_slept: 858 spin_lock(&dq_list_lock); 859 spin_lock(&dq_state_lock); 860 if (!sb_has_quota_active(sb, qid.type)) { 861 spin_unlock(&dq_state_lock); 862 spin_unlock(&dq_list_lock); 863 dquot = ERR_PTR(-ESRCH); 864 goto out; 865 } 866 spin_unlock(&dq_state_lock); 867 868 dquot = find_dquot(hashent, sb, qid); 869 if (!dquot) { 870 if (!empty) { 871 spin_unlock(&dq_list_lock); 872 empty = get_empty_dquot(sb, qid.type); 873 if (!empty) 874 schedule(); /* Try to wait for a moment... */ 875 goto we_slept; 876 } 877 dquot = empty; 878 empty = NULL; 879 dquot->dq_id = qid; 880 /* all dquots go on the inuse_list */ 881 put_inuse(dquot); 882 /* hash it first so it can be found */ 883 insert_dquot_hash(dquot); 884 spin_unlock(&dq_list_lock); 885 dqstats_inc(DQST_LOOKUPS); 886 } else { 887 if (!atomic_read(&dquot->dq_count)) 888 remove_free_dquot(dquot); 889 atomic_inc(&dquot->dq_count); 890 spin_unlock(&dq_list_lock); 891 dqstats_inc(DQST_CACHE_HITS); 892 dqstats_inc(DQST_LOOKUPS); 893 } 894 /* Wait for dq_lock - after this we know that either dquot_release() is 895 * already finished or it will be canceled due to dq_count > 1 test */ 896 wait_on_dquot(dquot); 897 /* Read the dquot / allocate space in quota file */ 898 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 899 int err; 900 901 err = sb->dq_op->acquire_dquot(dquot); 902 if (err < 0) { 903 dqput(dquot); 904 dquot = ERR_PTR(err); 905 goto out; 906 } 907 } 908 /* 909 * Make sure following reads see filled structure - paired with 910 * smp_mb__before_atomic() in dquot_acquire(). 911 */ 912 smp_rmb(); 913 #ifdef CONFIG_QUOTA_DEBUG 914 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 915 #endif 916 out: 917 if (empty) 918 do_destroy_dquot(empty); 919 920 return dquot; 921 } 922 EXPORT_SYMBOL(dqget); 923 924 static inline struct dquot **i_dquot(struct inode *inode) 925 { 926 return inode->i_sb->s_op->get_dquots(inode); 927 } 928 929 static int dqinit_needed(struct inode *inode, int type) 930 { 931 struct dquot * const *dquots; 932 int cnt; 933 934 if (IS_NOQUOTA(inode)) 935 return 0; 936 937 dquots = i_dquot(inode); 938 if (type != -1) 939 return !dquots[type]; 940 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 941 if (!dquots[cnt]) 942 return 1; 943 return 0; 944 } 945 946 /* This routine is guarded by s_umount semaphore */ 947 static int add_dquot_ref(struct super_block *sb, int type) 948 { 949 struct inode *inode, *old_inode = NULL; 950 #ifdef CONFIG_QUOTA_DEBUG 951 int reserved = 0; 952 #endif 953 int err = 0; 954 955 spin_lock(&sb->s_inode_list_lock); 956 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 957 spin_lock(&inode->i_lock); 958 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 959 !atomic_read(&inode->i_writecount) || 960 !dqinit_needed(inode, type)) { 961 spin_unlock(&inode->i_lock); 962 continue; 963 } 964 __iget(inode); 965 spin_unlock(&inode->i_lock); 966 spin_unlock(&sb->s_inode_list_lock); 967 968 #ifdef CONFIG_QUOTA_DEBUG 969 if (unlikely(inode_get_rsv_space(inode) > 0)) 970 reserved = 1; 971 #endif 972 iput(old_inode); 973 err = __dquot_initialize(inode, type); 974 if (err) { 975 iput(inode); 976 goto out; 977 } 978 979 /* 980 * We hold a reference to 'inode' so it couldn't have been 981 * removed from s_inodes list while we dropped the 982 * s_inode_list_lock. We cannot iput the inode now as we can be 983 * holding the last reference and we cannot iput it under 984 * s_inode_list_lock. So we keep the reference and iput it 985 * later. 986 */ 987 old_inode = inode; 988 spin_lock(&sb->s_inode_list_lock); 989 } 990 spin_unlock(&sb->s_inode_list_lock); 991 iput(old_inode); 992 out: 993 #ifdef CONFIG_QUOTA_DEBUG 994 if (reserved) { 995 quota_error(sb, "Writes happened before quota was turned on " 996 "thus quota information is probably inconsistent. " 997 "Please run quotacheck(8)"); 998 } 999 #endif 1000 return err; 1001 } 1002 1003 /* 1004 * Remove references to dquots from inode and add dquot to list for freeing 1005 * if we have the last reference to dquot 1006 */ 1007 static void remove_inode_dquot_ref(struct inode *inode, int type, 1008 struct list_head *tofree_head) 1009 { 1010 struct dquot **dquots = i_dquot(inode); 1011 struct dquot *dquot = dquots[type]; 1012 1013 if (!dquot) 1014 return; 1015 1016 dquots[type] = NULL; 1017 if (list_empty(&dquot->dq_free)) { 1018 /* 1019 * The inode still has reference to dquot so it can't be in the 1020 * free list 1021 */ 1022 spin_lock(&dq_list_lock); 1023 list_add(&dquot->dq_free, tofree_head); 1024 spin_unlock(&dq_list_lock); 1025 } else { 1026 /* 1027 * Dquot is already in a list to put so we won't drop the last 1028 * reference here. 1029 */ 1030 dqput(dquot); 1031 } 1032 } 1033 1034 /* 1035 * Free list of dquots 1036 * Dquots are removed from inodes and no new references can be got so we are 1037 * the only ones holding reference 1038 */ 1039 static void put_dquot_list(struct list_head *tofree_head) 1040 { 1041 struct list_head *act_head; 1042 struct dquot *dquot; 1043 1044 act_head = tofree_head->next; 1045 while (act_head != tofree_head) { 1046 dquot = list_entry(act_head, struct dquot, dq_free); 1047 act_head = act_head->next; 1048 /* Remove dquot from the list so we won't have problems... */ 1049 list_del_init(&dquot->dq_free); 1050 dqput(dquot); 1051 } 1052 } 1053 1054 static void remove_dquot_ref(struct super_block *sb, int type, 1055 struct list_head *tofree_head) 1056 { 1057 struct inode *inode; 1058 #ifdef CONFIG_QUOTA_DEBUG 1059 int reserved = 0; 1060 #endif 1061 1062 spin_lock(&sb->s_inode_list_lock); 1063 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1064 /* 1065 * We have to scan also I_NEW inodes because they can already 1066 * have quota pointer initialized. Luckily, we need to touch 1067 * only quota pointers and these have separate locking 1068 * (dq_data_lock). 1069 */ 1070 spin_lock(&dq_data_lock); 1071 if (!IS_NOQUOTA(inode)) { 1072 #ifdef CONFIG_QUOTA_DEBUG 1073 if (unlikely(inode_get_rsv_space(inode) > 0)) 1074 reserved = 1; 1075 #endif 1076 remove_inode_dquot_ref(inode, type, tofree_head); 1077 } 1078 spin_unlock(&dq_data_lock); 1079 } 1080 spin_unlock(&sb->s_inode_list_lock); 1081 #ifdef CONFIG_QUOTA_DEBUG 1082 if (reserved) { 1083 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1084 " was disabled thus quota information is probably " 1085 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1086 } 1087 #endif 1088 } 1089 1090 /* Gather all references from inodes and drop them */ 1091 static void drop_dquot_ref(struct super_block *sb, int type) 1092 { 1093 LIST_HEAD(tofree_head); 1094 1095 if (sb->dq_op) { 1096 remove_dquot_ref(sb, type, &tofree_head); 1097 synchronize_srcu(&dquot_srcu); 1098 put_dquot_list(&tofree_head); 1099 } 1100 } 1101 1102 static inline 1103 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1104 { 1105 if (dquot->dq_dqb.dqb_rsvspace >= number) 1106 dquot->dq_dqb.dqb_rsvspace -= number; 1107 else { 1108 WARN_ON_ONCE(1); 1109 dquot->dq_dqb.dqb_rsvspace = 0; 1110 } 1111 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1112 dquot->dq_dqb.dqb_bsoftlimit) 1113 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1114 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1115 } 1116 1117 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1118 { 1119 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1120 dquot->dq_dqb.dqb_curinodes >= number) 1121 dquot->dq_dqb.dqb_curinodes -= number; 1122 else 1123 dquot->dq_dqb.dqb_curinodes = 0; 1124 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1125 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1126 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1127 } 1128 1129 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1130 { 1131 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1132 dquot->dq_dqb.dqb_curspace >= number) 1133 dquot->dq_dqb.dqb_curspace -= number; 1134 else 1135 dquot->dq_dqb.dqb_curspace = 0; 1136 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1137 dquot->dq_dqb.dqb_bsoftlimit) 1138 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1139 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1140 } 1141 1142 struct dquot_warn { 1143 struct super_block *w_sb; 1144 struct kqid w_dq_id; 1145 short w_type; 1146 }; 1147 1148 static int warning_issued(struct dquot *dquot, const int warntype) 1149 { 1150 int flag = (warntype == QUOTA_NL_BHARDWARN || 1151 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1152 ((warntype == QUOTA_NL_IHARDWARN || 1153 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1154 1155 if (!flag) 1156 return 0; 1157 return test_and_set_bit(flag, &dquot->dq_flags); 1158 } 1159 1160 #ifdef CONFIG_PRINT_QUOTA_WARNING 1161 static int flag_print_warnings = 1; 1162 1163 static int need_print_warning(struct dquot_warn *warn) 1164 { 1165 if (!flag_print_warnings) 1166 return 0; 1167 1168 switch (warn->w_dq_id.type) { 1169 case USRQUOTA: 1170 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1171 case GRPQUOTA: 1172 return in_group_p(warn->w_dq_id.gid); 1173 case PRJQUOTA: 1174 return 1; 1175 } 1176 return 0; 1177 } 1178 1179 /* Print warning to user which exceeded quota */ 1180 static void print_warning(struct dquot_warn *warn) 1181 { 1182 char *msg = NULL; 1183 struct tty_struct *tty; 1184 int warntype = warn->w_type; 1185 1186 if (warntype == QUOTA_NL_IHARDBELOW || 1187 warntype == QUOTA_NL_ISOFTBELOW || 1188 warntype == QUOTA_NL_BHARDBELOW || 1189 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1190 return; 1191 1192 tty = get_current_tty(); 1193 if (!tty) 1194 return; 1195 tty_write_message(tty, warn->w_sb->s_id); 1196 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1197 tty_write_message(tty, ": warning, "); 1198 else 1199 tty_write_message(tty, ": write failed, "); 1200 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1201 switch (warntype) { 1202 case QUOTA_NL_IHARDWARN: 1203 msg = " file limit reached.\r\n"; 1204 break; 1205 case QUOTA_NL_ISOFTLONGWARN: 1206 msg = " file quota exceeded too long.\r\n"; 1207 break; 1208 case QUOTA_NL_ISOFTWARN: 1209 msg = " file quota exceeded.\r\n"; 1210 break; 1211 case QUOTA_NL_BHARDWARN: 1212 msg = " block limit reached.\r\n"; 1213 break; 1214 case QUOTA_NL_BSOFTLONGWARN: 1215 msg = " block quota exceeded too long.\r\n"; 1216 break; 1217 case QUOTA_NL_BSOFTWARN: 1218 msg = " block quota exceeded.\r\n"; 1219 break; 1220 } 1221 tty_write_message(tty, msg); 1222 tty_kref_put(tty); 1223 } 1224 #endif 1225 1226 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1227 int warntype) 1228 { 1229 if (warning_issued(dquot, warntype)) 1230 return; 1231 warn->w_type = warntype; 1232 warn->w_sb = dquot->dq_sb; 1233 warn->w_dq_id = dquot->dq_id; 1234 } 1235 1236 /* 1237 * Write warnings to the console and send warning messages over netlink. 1238 * 1239 * Note that this function can call into tty and networking code. 1240 */ 1241 static void flush_warnings(struct dquot_warn *warn) 1242 { 1243 int i; 1244 1245 for (i = 0; i < MAXQUOTAS; i++) { 1246 if (warn[i].w_type == QUOTA_NL_NOWARN) 1247 continue; 1248 #ifdef CONFIG_PRINT_QUOTA_WARNING 1249 print_warning(&warn[i]); 1250 #endif 1251 quota_send_warning(warn[i].w_dq_id, 1252 warn[i].w_sb->s_dev, warn[i].w_type); 1253 } 1254 } 1255 1256 static int ignore_hardlimit(struct dquot *dquot) 1257 { 1258 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1259 1260 return capable(CAP_SYS_RESOURCE) && 1261 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1262 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1263 } 1264 1265 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1266 struct dquot_warn *warn) 1267 { 1268 qsize_t newinodes; 1269 int ret = 0; 1270 1271 spin_lock(&dquot->dq_dqb_lock); 1272 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1273 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1274 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1275 goto add; 1276 1277 if (dquot->dq_dqb.dqb_ihardlimit && 1278 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1279 !ignore_hardlimit(dquot)) { 1280 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 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 && 1288 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1289 !ignore_hardlimit(dquot)) { 1290 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1291 ret = -EDQUOT; 1292 goto out; 1293 } 1294 1295 if (dquot->dq_dqb.dqb_isoftlimit && 1296 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1297 dquot->dq_dqb.dqb_itime == 0) { 1298 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1299 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1300 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1301 } 1302 add: 1303 dquot->dq_dqb.dqb_curinodes = newinodes; 1304 1305 out: 1306 spin_unlock(&dquot->dq_dqb_lock); 1307 return ret; 1308 } 1309 1310 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1311 qsize_t rsv_space, unsigned int flags, 1312 struct dquot_warn *warn) 1313 { 1314 qsize_t tspace; 1315 struct super_block *sb = dquot->dq_sb; 1316 int ret = 0; 1317 1318 spin_lock(&dquot->dq_dqb_lock); 1319 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1320 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1321 goto finish; 1322 1323 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1324 + space + rsv_space; 1325 1326 if (dquot->dq_dqb.dqb_bhardlimit && 1327 tspace > dquot->dq_dqb.dqb_bhardlimit && 1328 !ignore_hardlimit(dquot)) { 1329 if (flags & DQUOT_SPACE_WARN) 1330 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1331 ret = -EDQUOT; 1332 goto finish; 1333 } 1334 1335 if (dquot->dq_dqb.dqb_bsoftlimit && 1336 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1337 dquot->dq_dqb.dqb_btime && 1338 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1339 !ignore_hardlimit(dquot)) { 1340 if (flags & DQUOT_SPACE_WARN) 1341 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1342 ret = -EDQUOT; 1343 goto finish; 1344 } 1345 1346 if (dquot->dq_dqb.dqb_bsoftlimit && 1347 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1348 dquot->dq_dqb.dqb_btime == 0) { 1349 if (flags & DQUOT_SPACE_WARN) { 1350 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1351 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1352 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1353 } else { 1354 /* 1355 * We don't allow preallocation to exceed softlimit so exceeding will 1356 * be always printed 1357 */ 1358 ret = -EDQUOT; 1359 goto finish; 1360 } 1361 } 1362 finish: 1363 /* 1364 * We have to be careful and go through warning generation & grace time 1365 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1366 * only here... 1367 */ 1368 if (flags & DQUOT_SPACE_NOFAIL) 1369 ret = 0; 1370 if (!ret) { 1371 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1372 dquot->dq_dqb.dqb_curspace += space; 1373 } 1374 spin_unlock(&dquot->dq_dqb_lock); 1375 return ret; 1376 } 1377 1378 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1379 { 1380 qsize_t newinodes; 1381 1382 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1383 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1384 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1385 return QUOTA_NL_NOWARN; 1386 1387 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1388 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1389 return QUOTA_NL_ISOFTBELOW; 1390 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1391 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1392 return QUOTA_NL_IHARDBELOW; 1393 return QUOTA_NL_NOWARN; 1394 } 1395 1396 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1397 { 1398 qsize_t tspace; 1399 1400 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1401 1402 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1403 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1404 return QUOTA_NL_NOWARN; 1405 1406 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1407 return QUOTA_NL_BSOFTBELOW; 1408 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1409 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1410 return QUOTA_NL_BHARDBELOW; 1411 return QUOTA_NL_NOWARN; 1412 } 1413 1414 static int dquot_active(const struct inode *inode) 1415 { 1416 struct super_block *sb = inode->i_sb; 1417 1418 if (IS_NOQUOTA(inode)) 1419 return 0; 1420 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1421 } 1422 1423 /* 1424 * Initialize quota pointers in inode 1425 * 1426 * It is better to call this function outside of any transaction as it 1427 * might need a lot of space in journal for dquot structure allocation. 1428 */ 1429 static int __dquot_initialize(struct inode *inode, int type) 1430 { 1431 int cnt, init_needed = 0; 1432 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1433 struct super_block *sb = inode->i_sb; 1434 qsize_t rsv; 1435 int ret = 0; 1436 1437 if (!dquot_active(inode)) 1438 return 0; 1439 1440 dquots = i_dquot(inode); 1441 1442 /* First get references to structures we might need. */ 1443 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1444 struct kqid qid; 1445 kprojid_t projid; 1446 int rc; 1447 struct dquot *dquot; 1448 1449 if (type != -1 && cnt != type) 1450 continue; 1451 /* 1452 * The i_dquot should have been initialized in most cases, 1453 * we check it without locking here to avoid unnecessary 1454 * dqget()/dqput() calls. 1455 */ 1456 if (dquots[cnt]) 1457 continue; 1458 1459 if (!sb_has_quota_active(sb, cnt)) 1460 continue; 1461 1462 init_needed = 1; 1463 1464 switch (cnt) { 1465 case USRQUOTA: 1466 qid = make_kqid_uid(inode->i_uid); 1467 break; 1468 case GRPQUOTA: 1469 qid = make_kqid_gid(inode->i_gid); 1470 break; 1471 case PRJQUOTA: 1472 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1473 if (rc) 1474 continue; 1475 qid = make_kqid_projid(projid); 1476 break; 1477 } 1478 dquot = dqget(sb, qid); 1479 if (IS_ERR(dquot)) { 1480 /* We raced with somebody turning quotas off... */ 1481 if (PTR_ERR(dquot) != -ESRCH) { 1482 ret = PTR_ERR(dquot); 1483 goto out_put; 1484 } 1485 dquot = NULL; 1486 } 1487 got[cnt] = dquot; 1488 } 1489 1490 /* All required i_dquot has been initialized */ 1491 if (!init_needed) 1492 return 0; 1493 1494 spin_lock(&dq_data_lock); 1495 if (IS_NOQUOTA(inode)) 1496 goto out_lock; 1497 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1498 if (type != -1 && cnt != type) 1499 continue; 1500 /* Avoid races with quotaoff() */ 1501 if (!sb_has_quota_active(sb, cnt)) 1502 continue; 1503 /* We could race with quotaon or dqget() could have failed */ 1504 if (!got[cnt]) 1505 continue; 1506 if (!dquots[cnt]) { 1507 dquots[cnt] = got[cnt]; 1508 got[cnt] = NULL; 1509 /* 1510 * Make quota reservation system happy if someone 1511 * did a write before quota was turned on 1512 */ 1513 rsv = inode_get_rsv_space(inode); 1514 if (unlikely(rsv)) { 1515 spin_lock(&inode->i_lock); 1516 /* Get reservation again under proper lock */ 1517 rsv = __inode_get_rsv_space(inode); 1518 spin_lock(&dquots[cnt]->dq_dqb_lock); 1519 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1520 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1521 spin_unlock(&inode->i_lock); 1522 } 1523 } 1524 } 1525 out_lock: 1526 spin_unlock(&dq_data_lock); 1527 out_put: 1528 /* Drop unused references */ 1529 dqput_all(got); 1530 1531 return ret; 1532 } 1533 1534 int dquot_initialize(struct inode *inode) 1535 { 1536 return __dquot_initialize(inode, -1); 1537 } 1538 EXPORT_SYMBOL(dquot_initialize); 1539 1540 bool dquot_initialize_needed(struct inode *inode) 1541 { 1542 struct dquot **dquots; 1543 int i; 1544 1545 if (!dquot_active(inode)) 1546 return false; 1547 1548 dquots = i_dquot(inode); 1549 for (i = 0; i < MAXQUOTAS; i++) 1550 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1551 return true; 1552 return false; 1553 } 1554 EXPORT_SYMBOL(dquot_initialize_needed); 1555 1556 /* 1557 * Release all quotas referenced by inode. 1558 * 1559 * This function only be called on inode free or converting 1560 * a file to quota file, no other users for the i_dquot in 1561 * both cases, so we needn't call synchronize_srcu() after 1562 * clearing i_dquot. 1563 */ 1564 static void __dquot_drop(struct inode *inode) 1565 { 1566 int cnt; 1567 struct dquot **dquots = i_dquot(inode); 1568 struct dquot *put[MAXQUOTAS]; 1569 1570 spin_lock(&dq_data_lock); 1571 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1572 put[cnt] = dquots[cnt]; 1573 dquots[cnt] = NULL; 1574 } 1575 spin_unlock(&dq_data_lock); 1576 dqput_all(put); 1577 } 1578 1579 void dquot_drop(struct inode *inode) 1580 { 1581 struct dquot * const *dquots; 1582 int cnt; 1583 1584 if (IS_NOQUOTA(inode)) 1585 return; 1586 1587 /* 1588 * Test before calling to rule out calls from proc and such 1589 * where we are not allowed to block. Note that this is 1590 * actually reliable test even without the lock - the caller 1591 * must assure that nobody can come after the DQUOT_DROP and 1592 * add quota pointers back anyway. 1593 */ 1594 dquots = i_dquot(inode); 1595 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1596 if (dquots[cnt]) 1597 break; 1598 } 1599 1600 if (cnt < MAXQUOTAS) 1601 __dquot_drop(inode); 1602 } 1603 EXPORT_SYMBOL(dquot_drop); 1604 1605 /* 1606 * inode_reserved_space is managed internally by quota, and protected by 1607 * i_lock similar to i_blocks+i_bytes. 1608 */ 1609 static qsize_t *inode_reserved_space(struct inode * inode) 1610 { 1611 /* Filesystem must explicitly define it's own method in order to use 1612 * quota reservation interface */ 1613 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1614 return inode->i_sb->dq_op->get_reserved_space(inode); 1615 } 1616 1617 static qsize_t __inode_get_rsv_space(struct inode *inode) 1618 { 1619 if (!inode->i_sb->dq_op->get_reserved_space) 1620 return 0; 1621 return *inode_reserved_space(inode); 1622 } 1623 1624 static qsize_t inode_get_rsv_space(struct inode *inode) 1625 { 1626 qsize_t ret; 1627 1628 if (!inode->i_sb->dq_op->get_reserved_space) 1629 return 0; 1630 spin_lock(&inode->i_lock); 1631 ret = __inode_get_rsv_space(inode); 1632 spin_unlock(&inode->i_lock); 1633 return ret; 1634 } 1635 1636 /* 1637 * This functions updates i_blocks+i_bytes fields and quota information 1638 * (together with appropriate checks). 1639 * 1640 * NOTE: We absolutely rely on the fact that caller dirties the inode 1641 * (usually helpers in quotaops.h care about this) and holds a handle for 1642 * the current transaction so that dquot write and inode write go into the 1643 * same transaction. 1644 */ 1645 1646 /* 1647 * This operation can block, but only after everything is updated 1648 */ 1649 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1650 { 1651 int cnt, ret = 0, index; 1652 struct dquot_warn warn[MAXQUOTAS]; 1653 int reserve = flags & DQUOT_SPACE_RESERVE; 1654 struct dquot **dquots; 1655 1656 if (!dquot_active(inode)) { 1657 if (reserve) { 1658 spin_lock(&inode->i_lock); 1659 *inode_reserved_space(inode) += number; 1660 spin_unlock(&inode->i_lock); 1661 } else { 1662 inode_add_bytes(inode, number); 1663 } 1664 goto out; 1665 } 1666 1667 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1668 warn[cnt].w_type = QUOTA_NL_NOWARN; 1669 1670 dquots = i_dquot(inode); 1671 index = srcu_read_lock(&dquot_srcu); 1672 spin_lock(&inode->i_lock); 1673 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1674 if (!dquots[cnt]) 1675 continue; 1676 if (reserve) { 1677 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1678 &warn[cnt]); 1679 } else { 1680 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1681 &warn[cnt]); 1682 } 1683 if (ret) { 1684 /* Back out changes we already did */ 1685 for (cnt--; cnt >= 0; cnt--) { 1686 if (!dquots[cnt]) 1687 continue; 1688 spin_lock(&dquots[cnt]->dq_dqb_lock); 1689 if (reserve) 1690 dquot_free_reserved_space(dquots[cnt], 1691 number); 1692 else 1693 dquot_decr_space(dquots[cnt], number); 1694 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1695 } 1696 spin_unlock(&inode->i_lock); 1697 goto out_flush_warn; 1698 } 1699 } 1700 if (reserve) 1701 *inode_reserved_space(inode) += number; 1702 else 1703 __inode_add_bytes(inode, number); 1704 spin_unlock(&inode->i_lock); 1705 1706 if (reserve) 1707 goto out_flush_warn; 1708 mark_all_dquot_dirty(dquots); 1709 out_flush_warn: 1710 srcu_read_unlock(&dquot_srcu, index); 1711 flush_warnings(warn); 1712 out: 1713 return ret; 1714 } 1715 EXPORT_SYMBOL(__dquot_alloc_space); 1716 1717 /* 1718 * This operation can block, but only after everything is updated 1719 */ 1720 int dquot_alloc_inode(struct inode *inode) 1721 { 1722 int cnt, ret = 0, index; 1723 struct dquot_warn warn[MAXQUOTAS]; 1724 struct dquot * const *dquots; 1725 1726 if (!dquot_active(inode)) 1727 return 0; 1728 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1729 warn[cnt].w_type = QUOTA_NL_NOWARN; 1730 1731 dquots = i_dquot(inode); 1732 index = srcu_read_lock(&dquot_srcu); 1733 spin_lock(&inode->i_lock); 1734 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1735 if (!dquots[cnt]) 1736 continue; 1737 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1738 if (ret) { 1739 for (cnt--; cnt >= 0; cnt--) { 1740 if (!dquots[cnt]) 1741 continue; 1742 /* Back out changes we already did */ 1743 spin_lock(&dquots[cnt]->dq_dqb_lock); 1744 dquot_decr_inodes(dquots[cnt], 1); 1745 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1746 } 1747 goto warn_put_all; 1748 } 1749 } 1750 1751 warn_put_all: 1752 spin_unlock(&inode->i_lock); 1753 if (ret == 0) 1754 mark_all_dquot_dirty(dquots); 1755 srcu_read_unlock(&dquot_srcu, index); 1756 flush_warnings(warn); 1757 return ret; 1758 } 1759 EXPORT_SYMBOL(dquot_alloc_inode); 1760 1761 /* 1762 * Convert in-memory reserved quotas to real consumed quotas 1763 */ 1764 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1765 { 1766 struct dquot **dquots; 1767 int cnt, index; 1768 1769 if (!dquot_active(inode)) { 1770 spin_lock(&inode->i_lock); 1771 *inode_reserved_space(inode) -= number; 1772 __inode_add_bytes(inode, number); 1773 spin_unlock(&inode->i_lock); 1774 return 0; 1775 } 1776 1777 dquots = i_dquot(inode); 1778 index = srcu_read_lock(&dquot_srcu); 1779 spin_lock(&inode->i_lock); 1780 /* Claim reserved quotas to allocated quotas */ 1781 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1782 if (dquots[cnt]) { 1783 struct dquot *dquot = dquots[cnt]; 1784 1785 spin_lock(&dquot->dq_dqb_lock); 1786 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1787 number = dquot->dq_dqb.dqb_rsvspace; 1788 dquot->dq_dqb.dqb_curspace += number; 1789 dquot->dq_dqb.dqb_rsvspace -= number; 1790 spin_unlock(&dquot->dq_dqb_lock); 1791 } 1792 } 1793 /* Update inode bytes */ 1794 *inode_reserved_space(inode) -= number; 1795 __inode_add_bytes(inode, number); 1796 spin_unlock(&inode->i_lock); 1797 mark_all_dquot_dirty(dquots); 1798 srcu_read_unlock(&dquot_srcu, index); 1799 return 0; 1800 } 1801 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1802 1803 /* 1804 * Convert allocated space back to in-memory reserved quotas 1805 */ 1806 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1807 { 1808 struct dquot **dquots; 1809 int cnt, index; 1810 1811 if (!dquot_active(inode)) { 1812 spin_lock(&inode->i_lock); 1813 *inode_reserved_space(inode) += number; 1814 __inode_sub_bytes(inode, number); 1815 spin_unlock(&inode->i_lock); 1816 return; 1817 } 1818 1819 dquots = i_dquot(inode); 1820 index = srcu_read_lock(&dquot_srcu); 1821 spin_lock(&inode->i_lock); 1822 /* Claim reserved quotas to allocated quotas */ 1823 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1824 if (dquots[cnt]) { 1825 struct dquot *dquot = dquots[cnt]; 1826 1827 spin_lock(&dquot->dq_dqb_lock); 1828 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1829 number = dquot->dq_dqb.dqb_curspace; 1830 dquot->dq_dqb.dqb_rsvspace += number; 1831 dquot->dq_dqb.dqb_curspace -= number; 1832 spin_unlock(&dquot->dq_dqb_lock); 1833 } 1834 } 1835 /* Update inode bytes */ 1836 *inode_reserved_space(inode) += number; 1837 __inode_sub_bytes(inode, number); 1838 spin_unlock(&inode->i_lock); 1839 mark_all_dquot_dirty(dquots); 1840 srcu_read_unlock(&dquot_srcu, index); 1841 return; 1842 } 1843 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1844 1845 /* 1846 * This operation can block, but only after everything is updated 1847 */ 1848 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1849 { 1850 unsigned int cnt; 1851 struct dquot_warn warn[MAXQUOTAS]; 1852 struct dquot **dquots; 1853 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1854 1855 if (!dquot_active(inode)) { 1856 if (reserve) { 1857 spin_lock(&inode->i_lock); 1858 *inode_reserved_space(inode) -= number; 1859 spin_unlock(&inode->i_lock); 1860 } else { 1861 inode_sub_bytes(inode, number); 1862 } 1863 return; 1864 } 1865 1866 dquots = i_dquot(inode); 1867 index = srcu_read_lock(&dquot_srcu); 1868 spin_lock(&inode->i_lock); 1869 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1870 int wtype; 1871 1872 warn[cnt].w_type = QUOTA_NL_NOWARN; 1873 if (!dquots[cnt]) 1874 continue; 1875 spin_lock(&dquots[cnt]->dq_dqb_lock); 1876 wtype = info_bdq_free(dquots[cnt], number); 1877 if (wtype != QUOTA_NL_NOWARN) 1878 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1879 if (reserve) 1880 dquot_free_reserved_space(dquots[cnt], number); 1881 else 1882 dquot_decr_space(dquots[cnt], number); 1883 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1884 } 1885 if (reserve) 1886 *inode_reserved_space(inode) -= number; 1887 else 1888 __inode_sub_bytes(inode, number); 1889 spin_unlock(&inode->i_lock); 1890 1891 if (reserve) 1892 goto out_unlock; 1893 mark_all_dquot_dirty(dquots); 1894 out_unlock: 1895 srcu_read_unlock(&dquot_srcu, index); 1896 flush_warnings(warn); 1897 } 1898 EXPORT_SYMBOL(__dquot_free_space); 1899 1900 /* 1901 * This operation can block, but only after everything is updated 1902 */ 1903 void dquot_free_inode(struct inode *inode) 1904 { 1905 unsigned int cnt; 1906 struct dquot_warn warn[MAXQUOTAS]; 1907 struct dquot * const *dquots; 1908 int index; 1909 1910 if (!dquot_active(inode)) 1911 return; 1912 1913 dquots = i_dquot(inode); 1914 index = srcu_read_lock(&dquot_srcu); 1915 spin_lock(&inode->i_lock); 1916 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1917 int wtype; 1918 1919 warn[cnt].w_type = QUOTA_NL_NOWARN; 1920 if (!dquots[cnt]) 1921 continue; 1922 spin_lock(&dquots[cnt]->dq_dqb_lock); 1923 wtype = info_idq_free(dquots[cnt], 1); 1924 if (wtype != QUOTA_NL_NOWARN) 1925 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1926 dquot_decr_inodes(dquots[cnt], 1); 1927 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1928 } 1929 spin_unlock(&inode->i_lock); 1930 mark_all_dquot_dirty(dquots); 1931 srcu_read_unlock(&dquot_srcu, index); 1932 flush_warnings(warn); 1933 } 1934 EXPORT_SYMBOL(dquot_free_inode); 1935 1936 /* 1937 * Transfer the number of inode and blocks from one diskquota to an other. 1938 * On success, dquot references in transfer_to are consumed and references 1939 * to original dquots that need to be released are placed there. On failure, 1940 * references are kept untouched. 1941 * 1942 * This operation can block, but only after everything is updated 1943 * A transaction must be started when entering this function. 1944 * 1945 * We are holding reference on transfer_from & transfer_to, no need to 1946 * protect them by srcu_read_lock(). 1947 */ 1948 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1949 { 1950 qsize_t cur_space; 1951 qsize_t rsv_space = 0; 1952 qsize_t inode_usage = 1; 1953 struct dquot *transfer_from[MAXQUOTAS] = {}; 1954 int cnt, ret = 0; 1955 char is_valid[MAXQUOTAS] = {}; 1956 struct dquot_warn warn_to[MAXQUOTAS]; 1957 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1958 struct dquot_warn warn_from_space[MAXQUOTAS]; 1959 1960 if (IS_NOQUOTA(inode)) 1961 return 0; 1962 1963 if (inode->i_sb->dq_op->get_inode_usage) { 1964 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1965 if (ret) 1966 return ret; 1967 } 1968 1969 /* Initialize the arrays */ 1970 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1971 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1972 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1973 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1974 } 1975 1976 spin_lock(&dq_data_lock); 1977 spin_lock(&inode->i_lock); 1978 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1979 spin_unlock(&inode->i_lock); 1980 spin_unlock(&dq_data_lock); 1981 return 0; 1982 } 1983 cur_space = __inode_get_bytes(inode); 1984 rsv_space = __inode_get_rsv_space(inode); 1985 /* 1986 * Build the transfer_from list, check limits, and update usage in 1987 * the target structures. 1988 */ 1989 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1990 /* 1991 * Skip changes for same uid or gid or for turned off quota-type. 1992 */ 1993 if (!transfer_to[cnt]) 1994 continue; 1995 /* Avoid races with quotaoff() */ 1996 if (!sb_has_quota_active(inode->i_sb, cnt)) 1997 continue; 1998 is_valid[cnt] = 1; 1999 transfer_from[cnt] = i_dquot(inode)[cnt]; 2000 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 2001 &warn_to[cnt]); 2002 if (ret) 2003 goto over_quota; 2004 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 2005 DQUOT_SPACE_WARN, &warn_to[cnt]); 2006 if (ret) { 2007 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2008 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2009 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2010 goto over_quota; 2011 } 2012 } 2013 2014 /* Decrease usage for source structures and update quota pointers */ 2015 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2016 if (!is_valid[cnt]) 2017 continue; 2018 /* Due to IO error we might not have transfer_from[] structure */ 2019 if (transfer_from[cnt]) { 2020 int wtype; 2021 2022 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2023 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2024 if (wtype != QUOTA_NL_NOWARN) 2025 prepare_warning(&warn_from_inodes[cnt], 2026 transfer_from[cnt], wtype); 2027 wtype = info_bdq_free(transfer_from[cnt], 2028 cur_space + rsv_space); 2029 if (wtype != QUOTA_NL_NOWARN) 2030 prepare_warning(&warn_from_space[cnt], 2031 transfer_from[cnt], wtype); 2032 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2033 dquot_decr_space(transfer_from[cnt], cur_space); 2034 dquot_free_reserved_space(transfer_from[cnt], 2035 rsv_space); 2036 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2037 } 2038 i_dquot(inode)[cnt] = transfer_to[cnt]; 2039 } 2040 spin_unlock(&inode->i_lock); 2041 spin_unlock(&dq_data_lock); 2042 2043 mark_all_dquot_dirty(transfer_from); 2044 mark_all_dquot_dirty(transfer_to); 2045 flush_warnings(warn_to); 2046 flush_warnings(warn_from_inodes); 2047 flush_warnings(warn_from_space); 2048 /* Pass back references to put */ 2049 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2050 if (is_valid[cnt]) 2051 transfer_to[cnt] = transfer_from[cnt]; 2052 return 0; 2053 over_quota: 2054 /* Back out changes we already did */ 2055 for (cnt--; cnt >= 0; cnt--) { 2056 if (!is_valid[cnt]) 2057 continue; 2058 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2059 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2060 dquot_decr_space(transfer_to[cnt], cur_space); 2061 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2062 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2063 } 2064 spin_unlock(&inode->i_lock); 2065 spin_unlock(&dq_data_lock); 2066 flush_warnings(warn_to); 2067 return ret; 2068 } 2069 EXPORT_SYMBOL(__dquot_transfer); 2070 2071 /* Wrapper for transferring ownership of an inode for uid/gid only 2072 * Called from FSXXX_setattr() 2073 */ 2074 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2075 { 2076 struct dquot *transfer_to[MAXQUOTAS] = {}; 2077 struct dquot *dquot; 2078 struct super_block *sb = inode->i_sb; 2079 int ret; 2080 2081 if (!dquot_active(inode)) 2082 return 0; 2083 2084 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2085 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2086 if (IS_ERR(dquot)) { 2087 if (PTR_ERR(dquot) != -ESRCH) { 2088 ret = PTR_ERR(dquot); 2089 goto out_put; 2090 } 2091 dquot = NULL; 2092 } 2093 transfer_to[USRQUOTA] = dquot; 2094 } 2095 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2096 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2097 if (IS_ERR(dquot)) { 2098 if (PTR_ERR(dquot) != -ESRCH) { 2099 ret = PTR_ERR(dquot); 2100 goto out_put; 2101 } 2102 dquot = NULL; 2103 } 2104 transfer_to[GRPQUOTA] = dquot; 2105 } 2106 ret = __dquot_transfer(inode, transfer_to); 2107 out_put: 2108 dqput_all(transfer_to); 2109 return ret; 2110 } 2111 EXPORT_SYMBOL(dquot_transfer); 2112 2113 /* 2114 * Write info of quota file to disk 2115 */ 2116 int dquot_commit_info(struct super_block *sb, int type) 2117 { 2118 struct quota_info *dqopt = sb_dqopt(sb); 2119 2120 return dqopt->ops[type]->write_file_info(sb, type); 2121 } 2122 EXPORT_SYMBOL(dquot_commit_info); 2123 2124 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2125 { 2126 struct quota_info *dqopt = sb_dqopt(sb); 2127 2128 if (!sb_has_quota_active(sb, qid->type)) 2129 return -ESRCH; 2130 if (!dqopt->ops[qid->type]->get_next_id) 2131 return -ENOSYS; 2132 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2133 } 2134 EXPORT_SYMBOL(dquot_get_next_id); 2135 2136 /* 2137 * Definitions of diskquota operations. 2138 */ 2139 const struct dquot_operations dquot_operations = { 2140 .write_dquot = dquot_commit, 2141 .acquire_dquot = dquot_acquire, 2142 .release_dquot = dquot_release, 2143 .mark_dirty = dquot_mark_dquot_dirty, 2144 .write_info = dquot_commit_info, 2145 .alloc_dquot = dquot_alloc, 2146 .destroy_dquot = dquot_destroy, 2147 .get_next_id = dquot_get_next_id, 2148 }; 2149 EXPORT_SYMBOL(dquot_operations); 2150 2151 /* 2152 * Generic helper for ->open on filesystems supporting disk quotas. 2153 */ 2154 int dquot_file_open(struct inode *inode, struct file *file) 2155 { 2156 int error; 2157 2158 error = generic_file_open(inode, file); 2159 if (!error && (file->f_mode & FMODE_WRITE)) 2160 error = dquot_initialize(inode); 2161 return error; 2162 } 2163 EXPORT_SYMBOL(dquot_file_open); 2164 2165 /* 2166 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2167 */ 2168 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2169 { 2170 int cnt, ret = 0; 2171 struct quota_info *dqopt = sb_dqopt(sb); 2172 struct inode *toputinode[MAXQUOTAS]; 2173 2174 /* s_umount should be held in exclusive mode */ 2175 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2176 up_read(&sb->s_umount); 2177 2178 /* Cannot turn off usage accounting without turning off limits, or 2179 * suspend quotas and simultaneously turn quotas off. */ 2180 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2181 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2182 DQUOT_USAGE_ENABLED))) 2183 return -EINVAL; 2184 2185 /* 2186 * Skip everything if there's nothing to do. We have to do this because 2187 * sometimes we are called when fill_super() failed and calling 2188 * sync_fs() in such cases does no good. 2189 */ 2190 if (!sb_any_quota_loaded(sb)) 2191 return 0; 2192 2193 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2194 toputinode[cnt] = NULL; 2195 if (type != -1 && cnt != type) 2196 continue; 2197 if (!sb_has_quota_loaded(sb, cnt)) 2198 continue; 2199 2200 if (flags & DQUOT_SUSPENDED) { 2201 spin_lock(&dq_state_lock); 2202 dqopt->flags |= 2203 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2204 spin_unlock(&dq_state_lock); 2205 } else { 2206 spin_lock(&dq_state_lock); 2207 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2208 /* Turning off suspended quotas? */ 2209 if (!sb_has_quota_loaded(sb, cnt) && 2210 sb_has_quota_suspended(sb, cnt)) { 2211 dqopt->flags &= ~dquot_state_flag( 2212 DQUOT_SUSPENDED, cnt); 2213 spin_unlock(&dq_state_lock); 2214 iput(dqopt->files[cnt]); 2215 dqopt->files[cnt] = NULL; 2216 continue; 2217 } 2218 spin_unlock(&dq_state_lock); 2219 } 2220 2221 /* We still have to keep quota loaded? */ 2222 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2223 continue; 2224 2225 /* Note: these are blocking operations */ 2226 drop_dquot_ref(sb, cnt); 2227 invalidate_dquots(sb, cnt); 2228 /* 2229 * Now all dquots should be invalidated, all writes done so we 2230 * should be only users of the info. No locks needed. 2231 */ 2232 if (info_dirty(&dqopt->info[cnt])) 2233 sb->dq_op->write_info(sb, cnt); 2234 if (dqopt->ops[cnt]->free_file_info) 2235 dqopt->ops[cnt]->free_file_info(sb, cnt); 2236 put_quota_format(dqopt->info[cnt].dqi_format); 2237 2238 toputinode[cnt] = dqopt->files[cnt]; 2239 if (!sb_has_quota_loaded(sb, cnt)) 2240 dqopt->files[cnt] = NULL; 2241 dqopt->info[cnt].dqi_flags = 0; 2242 dqopt->info[cnt].dqi_igrace = 0; 2243 dqopt->info[cnt].dqi_bgrace = 0; 2244 dqopt->ops[cnt] = NULL; 2245 } 2246 2247 /* Skip syncing and setting flags if quota files are hidden */ 2248 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2249 goto put_inodes; 2250 2251 /* Sync the superblock so that buffers with quota data are written to 2252 * disk (and so userspace sees correct data afterwards). */ 2253 if (sb->s_op->sync_fs) 2254 sb->s_op->sync_fs(sb, 1); 2255 sync_blockdev(sb->s_bdev); 2256 /* Now the quota files are just ordinary files and we can set the 2257 * inode flags back. Moreover we discard the pagecache so that 2258 * userspace sees the writes we did bypassing the pagecache. We 2259 * must also discard the blockdev buffers so that we see the 2260 * changes done by userspace on the next quotaon() */ 2261 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2262 /* This can happen when suspending quotas on remount-ro... */ 2263 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { 2264 inode_lock(toputinode[cnt]); 2265 toputinode[cnt]->i_flags &= ~S_NOQUOTA; 2266 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 2267 inode_unlock(toputinode[cnt]); 2268 mark_inode_dirty_sync(toputinode[cnt]); 2269 } 2270 if (sb->s_bdev) 2271 invalidate_bdev(sb->s_bdev); 2272 put_inodes: 2273 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2274 if (toputinode[cnt]) { 2275 /* On remount RO, we keep the inode pointer so that we 2276 * can reenable quota on the subsequent remount RW. We 2277 * have to check 'flags' variable and not use sb_has_ 2278 * function because another quotaon / quotaoff could 2279 * change global state before we got here. We refuse 2280 * to suspend quotas when there is pending delete on 2281 * the quota file... */ 2282 if (!(flags & DQUOT_SUSPENDED)) 2283 iput(toputinode[cnt]); 2284 else if (!toputinode[cnt]->i_nlink) 2285 ret = -EBUSY; 2286 } 2287 return ret; 2288 } 2289 EXPORT_SYMBOL(dquot_disable); 2290 2291 int dquot_quota_off(struct super_block *sb, int type) 2292 { 2293 return dquot_disable(sb, type, 2294 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2295 } 2296 EXPORT_SYMBOL(dquot_quota_off); 2297 2298 /* 2299 * Turn quotas on on a device 2300 */ 2301 2302 /* 2303 * Helper function to turn quotas on when we already have the inode of 2304 * quota file and no quota information is loaded. 2305 */ 2306 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2307 unsigned int flags) 2308 { 2309 struct quota_format_type *fmt = find_quota_format(format_id); 2310 struct super_block *sb = inode->i_sb; 2311 struct quota_info *dqopt = sb_dqopt(sb); 2312 int error; 2313 2314 if (!fmt) 2315 return -ESRCH; 2316 if (!S_ISREG(inode->i_mode)) { 2317 error = -EACCES; 2318 goto out_fmt; 2319 } 2320 if (IS_RDONLY(inode)) { 2321 error = -EROFS; 2322 goto out_fmt; 2323 } 2324 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2325 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2326 error = -EINVAL; 2327 goto out_fmt; 2328 } 2329 /* Filesystems outside of init_user_ns not yet supported */ 2330 if (sb->s_user_ns != &init_user_ns) { 2331 error = -EINVAL; 2332 goto out_fmt; 2333 } 2334 /* Usage always has to be set... */ 2335 if (!(flags & DQUOT_USAGE_ENABLED)) { 2336 error = -EINVAL; 2337 goto out_fmt; 2338 } 2339 if (sb_has_quota_loaded(sb, type)) { 2340 error = -EBUSY; 2341 goto out_fmt; 2342 } 2343 2344 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2345 /* As we bypass the pagecache we must now flush all the 2346 * dirty data and invalidate caches so that kernel sees 2347 * changes from userspace. It is not enough to just flush 2348 * the quota file since if blocksize < pagesize, invalidation 2349 * of the cache could fail because of other unrelated dirty 2350 * data */ 2351 sync_filesystem(sb); 2352 invalidate_bdev(sb->s_bdev); 2353 } 2354 2355 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2356 /* We don't want quota and atime on quota files (deadlocks 2357 * possible) Also nobody should write to the file - we use 2358 * special IO operations which ignore the immutable bit. */ 2359 inode_lock(inode); 2360 inode->i_flags |= S_NOQUOTA; 2361 inode_unlock(inode); 2362 /* 2363 * When S_NOQUOTA is set, remove dquot references as no more 2364 * references can be added 2365 */ 2366 __dquot_drop(inode); 2367 } 2368 2369 error = -EIO; 2370 dqopt->files[type] = igrab(inode); 2371 if (!dqopt->files[type]) 2372 goto out_file_flags; 2373 error = -EINVAL; 2374 if (!fmt->qf_ops->check_quota_file(sb, type)) 2375 goto out_file_init; 2376 2377 dqopt->ops[type] = fmt->qf_ops; 2378 dqopt->info[type].dqi_format = fmt; 2379 dqopt->info[type].dqi_fmt_id = format_id; 2380 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2381 error = dqopt->ops[type]->read_file_info(sb, type); 2382 if (error < 0) 2383 goto out_file_init; 2384 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2385 spin_lock(&dq_data_lock); 2386 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2387 spin_unlock(&dq_data_lock); 2388 } 2389 spin_lock(&dq_state_lock); 2390 dqopt->flags |= dquot_state_flag(flags, type); 2391 spin_unlock(&dq_state_lock); 2392 2393 error = add_dquot_ref(sb, type); 2394 if (error) 2395 dquot_disable(sb, type, flags); 2396 2397 return error; 2398 out_file_init: 2399 dqopt->files[type] = NULL; 2400 iput(inode); 2401 out_file_flags: 2402 inode_lock(inode); 2403 inode->i_flags &= ~S_NOQUOTA; 2404 inode_unlock(inode); 2405 out_fmt: 2406 put_quota_format(fmt); 2407 2408 return error; 2409 } 2410 2411 /* Reenable quotas on remount RW */ 2412 int dquot_resume(struct super_block *sb, int type) 2413 { 2414 struct quota_info *dqopt = sb_dqopt(sb); 2415 struct inode *inode; 2416 int ret = 0, cnt; 2417 unsigned int flags; 2418 2419 /* s_umount should be held in exclusive mode */ 2420 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2421 up_read(&sb->s_umount); 2422 2423 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2424 if (type != -1 && cnt != type) 2425 continue; 2426 if (!sb_has_quota_suspended(sb, cnt)) 2427 continue; 2428 2429 inode = dqopt->files[cnt]; 2430 dqopt->files[cnt] = NULL; 2431 spin_lock(&dq_state_lock); 2432 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2433 DQUOT_LIMITS_ENABLED, 2434 cnt); 2435 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2436 spin_unlock(&dq_state_lock); 2437 2438 flags = dquot_generic_flag(flags, cnt); 2439 ret = vfs_load_quota_inode(inode, cnt, 2440 dqopt->info[cnt].dqi_fmt_id, flags); 2441 iput(inode); 2442 } 2443 2444 return ret; 2445 } 2446 EXPORT_SYMBOL(dquot_resume); 2447 2448 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2449 const struct path *path) 2450 { 2451 int error = security_quota_on(path->dentry); 2452 if (error) 2453 return error; 2454 /* Quota file not on the same filesystem? */ 2455 if (path->dentry->d_sb != sb) 2456 error = -EXDEV; 2457 else 2458 error = vfs_load_quota_inode(d_inode(path->dentry), type, 2459 format_id, DQUOT_USAGE_ENABLED | 2460 DQUOT_LIMITS_ENABLED); 2461 return error; 2462 } 2463 EXPORT_SYMBOL(dquot_quota_on); 2464 2465 /* 2466 * More powerful function for turning on quotas allowing setting 2467 * of individual quota flags 2468 */ 2469 int dquot_enable(struct inode *inode, int type, int format_id, 2470 unsigned int flags) 2471 { 2472 struct super_block *sb = inode->i_sb; 2473 2474 /* Just unsuspend quotas? */ 2475 BUG_ON(flags & DQUOT_SUSPENDED); 2476 /* s_umount should be held in exclusive mode */ 2477 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2478 up_read(&sb->s_umount); 2479 2480 if (!flags) 2481 return 0; 2482 /* Just updating flags needed? */ 2483 if (sb_has_quota_loaded(sb, type)) { 2484 if (flags & DQUOT_USAGE_ENABLED && 2485 sb_has_quota_usage_enabled(sb, type)) 2486 return -EBUSY; 2487 if (flags & DQUOT_LIMITS_ENABLED && 2488 sb_has_quota_limits_enabled(sb, type)) 2489 return -EBUSY; 2490 spin_lock(&dq_state_lock); 2491 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2492 spin_unlock(&dq_state_lock); 2493 return 0; 2494 } 2495 2496 return vfs_load_quota_inode(inode, type, format_id, flags); 2497 } 2498 EXPORT_SYMBOL(dquot_enable); 2499 2500 /* 2501 * This function is used when filesystem needs to initialize quotas 2502 * during mount time. 2503 */ 2504 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2505 int format_id, int type) 2506 { 2507 struct dentry *dentry; 2508 int error; 2509 2510 dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2511 if (IS_ERR(dentry)) 2512 return PTR_ERR(dentry); 2513 2514 if (d_really_is_negative(dentry)) { 2515 error = -ENOENT; 2516 goto out; 2517 } 2518 2519 error = security_quota_on(dentry); 2520 if (!error) 2521 error = vfs_load_quota_inode(d_inode(dentry), type, format_id, 2522 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2523 2524 out: 2525 dput(dentry); 2526 return error; 2527 } 2528 EXPORT_SYMBOL(dquot_quota_on_mount); 2529 2530 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2531 { 2532 int ret; 2533 int type; 2534 struct quota_info *dqopt = sb_dqopt(sb); 2535 2536 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2537 return -ENOSYS; 2538 /* Accounting cannot be turned on while fs is mounted */ 2539 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2540 if (!flags) 2541 return -EINVAL; 2542 for (type = 0; type < MAXQUOTAS; type++) { 2543 if (!(flags & qtype_enforce_flag(type))) 2544 continue; 2545 /* Can't enforce without accounting */ 2546 if (!sb_has_quota_usage_enabled(sb, type)) 2547 return -EINVAL; 2548 ret = dquot_enable(dqopt->files[type], type, 2549 dqopt->info[type].dqi_fmt_id, 2550 DQUOT_LIMITS_ENABLED); 2551 if (ret < 0) 2552 goto out_err; 2553 } 2554 return 0; 2555 out_err: 2556 /* Backout enforcement enablement we already did */ 2557 for (type--; type >= 0; type--) { 2558 if (flags & qtype_enforce_flag(type)) 2559 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2560 } 2561 /* Error code translation for better compatibility with XFS */ 2562 if (ret == -EBUSY) 2563 ret = -EEXIST; 2564 return ret; 2565 } 2566 2567 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2568 { 2569 int ret; 2570 int type; 2571 struct quota_info *dqopt = sb_dqopt(sb); 2572 2573 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2574 return -ENOSYS; 2575 /* 2576 * We don't support turning off accounting via quotactl. In principle 2577 * quota infrastructure can do this but filesystems don't expect 2578 * userspace to be able to do it. 2579 */ 2580 if (flags & 2581 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2582 return -EOPNOTSUPP; 2583 2584 /* Filter out limits not enabled */ 2585 for (type = 0; type < MAXQUOTAS; type++) 2586 if (!sb_has_quota_limits_enabled(sb, type)) 2587 flags &= ~qtype_enforce_flag(type); 2588 /* Nothing left? */ 2589 if (!flags) 2590 return -EEXIST; 2591 for (type = 0; type < MAXQUOTAS; type++) { 2592 if (flags & qtype_enforce_flag(type)) { 2593 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2594 if (ret < 0) 2595 goto out_err; 2596 } 2597 } 2598 return 0; 2599 out_err: 2600 /* Backout enforcement disabling we already did */ 2601 for (type--; type >= 0; type--) { 2602 if (flags & qtype_enforce_flag(type)) 2603 dquot_enable(dqopt->files[type], type, 2604 dqopt->info[type].dqi_fmt_id, 2605 DQUOT_LIMITS_ENABLED); 2606 } 2607 return ret; 2608 } 2609 2610 /* Generic routine for getting common part of quota structure */ 2611 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2612 { 2613 struct mem_dqblk *dm = &dquot->dq_dqb; 2614 2615 memset(di, 0, sizeof(*di)); 2616 spin_lock(&dquot->dq_dqb_lock); 2617 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2618 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2619 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2620 di->d_ino_softlimit = dm->dqb_isoftlimit; 2621 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2622 di->d_ino_count = dm->dqb_curinodes; 2623 di->d_spc_timer = dm->dqb_btime; 2624 di->d_ino_timer = dm->dqb_itime; 2625 spin_unlock(&dquot->dq_dqb_lock); 2626 } 2627 2628 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2629 struct qc_dqblk *di) 2630 { 2631 struct dquot *dquot; 2632 2633 dquot = dqget(sb, qid); 2634 if (IS_ERR(dquot)) 2635 return PTR_ERR(dquot); 2636 do_get_dqblk(dquot, di); 2637 dqput(dquot); 2638 2639 return 0; 2640 } 2641 EXPORT_SYMBOL(dquot_get_dqblk); 2642 2643 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2644 struct qc_dqblk *di) 2645 { 2646 struct dquot *dquot; 2647 int err; 2648 2649 if (!sb->dq_op->get_next_id) 2650 return -ENOSYS; 2651 err = sb->dq_op->get_next_id(sb, qid); 2652 if (err < 0) 2653 return err; 2654 dquot = dqget(sb, *qid); 2655 if (IS_ERR(dquot)) 2656 return PTR_ERR(dquot); 2657 do_get_dqblk(dquot, di); 2658 dqput(dquot); 2659 2660 return 0; 2661 } 2662 EXPORT_SYMBOL(dquot_get_next_dqblk); 2663 2664 #define VFS_QC_MASK \ 2665 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2666 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2667 QC_SPC_TIMER | QC_INO_TIMER) 2668 2669 /* Generic routine for setting common part of quota structure */ 2670 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2671 { 2672 struct mem_dqblk *dm = &dquot->dq_dqb; 2673 int check_blim = 0, check_ilim = 0; 2674 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2675 2676 if (di->d_fieldmask & ~VFS_QC_MASK) 2677 return -EINVAL; 2678 2679 if (((di->d_fieldmask & QC_SPC_SOFT) && 2680 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2681 ((di->d_fieldmask & QC_SPC_HARD) && 2682 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2683 ((di->d_fieldmask & QC_INO_SOFT) && 2684 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2685 ((di->d_fieldmask & QC_INO_HARD) && 2686 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2687 return -ERANGE; 2688 2689 spin_lock(&dquot->dq_dqb_lock); 2690 if (di->d_fieldmask & QC_SPACE) { 2691 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2692 check_blim = 1; 2693 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2694 } 2695 2696 if (di->d_fieldmask & QC_SPC_SOFT) 2697 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2698 if (di->d_fieldmask & QC_SPC_HARD) 2699 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2700 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2701 check_blim = 1; 2702 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2703 } 2704 2705 if (di->d_fieldmask & QC_INO_COUNT) { 2706 dm->dqb_curinodes = di->d_ino_count; 2707 check_ilim = 1; 2708 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2709 } 2710 2711 if (di->d_fieldmask & QC_INO_SOFT) 2712 dm->dqb_isoftlimit = di->d_ino_softlimit; 2713 if (di->d_fieldmask & QC_INO_HARD) 2714 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2715 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2716 check_ilim = 1; 2717 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2718 } 2719 2720 if (di->d_fieldmask & QC_SPC_TIMER) { 2721 dm->dqb_btime = di->d_spc_timer; 2722 check_blim = 1; 2723 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2724 } 2725 2726 if (di->d_fieldmask & QC_INO_TIMER) { 2727 dm->dqb_itime = di->d_ino_timer; 2728 check_ilim = 1; 2729 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2730 } 2731 2732 if (check_blim) { 2733 if (!dm->dqb_bsoftlimit || 2734 dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) { 2735 dm->dqb_btime = 0; 2736 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2737 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2738 /* Set grace only if user hasn't provided his own... */ 2739 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2740 } 2741 if (check_ilim) { 2742 if (!dm->dqb_isoftlimit || 2743 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2744 dm->dqb_itime = 0; 2745 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2746 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2747 /* Set grace only if user hasn't provided his own... */ 2748 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2749 } 2750 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2751 dm->dqb_isoftlimit) 2752 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2753 else 2754 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2755 spin_unlock(&dquot->dq_dqb_lock); 2756 mark_dquot_dirty(dquot); 2757 2758 return 0; 2759 } 2760 2761 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2762 struct qc_dqblk *di) 2763 { 2764 struct dquot *dquot; 2765 int rc; 2766 2767 dquot = dqget(sb, qid); 2768 if (IS_ERR(dquot)) { 2769 rc = PTR_ERR(dquot); 2770 goto out; 2771 } 2772 rc = do_set_dqblk(dquot, di); 2773 dqput(dquot); 2774 out: 2775 return rc; 2776 } 2777 EXPORT_SYMBOL(dquot_set_dqblk); 2778 2779 /* Generic routine for getting common part of quota file information */ 2780 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2781 { 2782 struct mem_dqinfo *mi; 2783 struct qc_type_state *tstate; 2784 struct quota_info *dqopt = sb_dqopt(sb); 2785 int type; 2786 2787 memset(state, 0, sizeof(*state)); 2788 for (type = 0; type < MAXQUOTAS; type++) { 2789 if (!sb_has_quota_active(sb, type)) 2790 continue; 2791 tstate = state->s_state + type; 2792 mi = sb_dqopt(sb)->info + type; 2793 tstate->flags = QCI_ACCT_ENABLED; 2794 spin_lock(&dq_data_lock); 2795 if (mi->dqi_flags & DQF_SYS_FILE) 2796 tstate->flags |= QCI_SYSFILE; 2797 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2798 tstate->flags |= QCI_ROOT_SQUASH; 2799 if (sb_has_quota_limits_enabled(sb, type)) 2800 tstate->flags |= QCI_LIMITS_ENFORCED; 2801 tstate->spc_timelimit = mi->dqi_bgrace; 2802 tstate->ino_timelimit = mi->dqi_igrace; 2803 tstate->ino = dqopt->files[type]->i_ino; 2804 tstate->blocks = dqopt->files[type]->i_blocks; 2805 tstate->nextents = 1; /* We don't know... */ 2806 spin_unlock(&dq_data_lock); 2807 } 2808 return 0; 2809 } 2810 EXPORT_SYMBOL(dquot_get_state); 2811 2812 /* Generic routine for setting common part of quota file information */ 2813 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2814 { 2815 struct mem_dqinfo *mi; 2816 int err = 0; 2817 2818 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2819 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2820 return -EINVAL; 2821 if (!sb_has_quota_active(sb, type)) 2822 return -ESRCH; 2823 mi = sb_dqopt(sb)->info + type; 2824 if (ii->i_fieldmask & QC_FLAGS) { 2825 if ((ii->i_flags & QCI_ROOT_SQUASH && 2826 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2827 return -EINVAL; 2828 } 2829 spin_lock(&dq_data_lock); 2830 if (ii->i_fieldmask & QC_SPC_TIMER) 2831 mi->dqi_bgrace = ii->i_spc_timelimit; 2832 if (ii->i_fieldmask & QC_INO_TIMER) 2833 mi->dqi_igrace = ii->i_ino_timelimit; 2834 if (ii->i_fieldmask & QC_FLAGS) { 2835 if (ii->i_flags & QCI_ROOT_SQUASH) 2836 mi->dqi_flags |= DQF_ROOT_SQUASH; 2837 else 2838 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2839 } 2840 spin_unlock(&dq_data_lock); 2841 mark_info_dirty(sb, type); 2842 /* Force write to disk */ 2843 sb->dq_op->write_info(sb, type); 2844 return err; 2845 } 2846 EXPORT_SYMBOL(dquot_set_dqinfo); 2847 2848 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2849 .quota_enable = dquot_quota_enable, 2850 .quota_disable = dquot_quota_disable, 2851 .quota_sync = dquot_quota_sync, 2852 .get_state = dquot_get_state, 2853 .set_info = dquot_set_dqinfo, 2854 .get_dqblk = dquot_get_dqblk, 2855 .get_nextdqblk = dquot_get_next_dqblk, 2856 .set_dqblk = dquot_set_dqblk 2857 }; 2858 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2859 2860 static int do_proc_dqstats(struct ctl_table *table, int write, 2861 void __user *buffer, size_t *lenp, loff_t *ppos) 2862 { 2863 unsigned int type = (int *)table->data - dqstats.stat; 2864 2865 /* Update global table */ 2866 dqstats.stat[type] = 2867 percpu_counter_sum_positive(&dqstats.counter[type]); 2868 return proc_dointvec(table, write, buffer, lenp, ppos); 2869 } 2870 2871 static struct ctl_table fs_dqstats_table[] = { 2872 { 2873 .procname = "lookups", 2874 .data = &dqstats.stat[DQST_LOOKUPS], 2875 .maxlen = sizeof(int), 2876 .mode = 0444, 2877 .proc_handler = do_proc_dqstats, 2878 }, 2879 { 2880 .procname = "drops", 2881 .data = &dqstats.stat[DQST_DROPS], 2882 .maxlen = sizeof(int), 2883 .mode = 0444, 2884 .proc_handler = do_proc_dqstats, 2885 }, 2886 { 2887 .procname = "reads", 2888 .data = &dqstats.stat[DQST_READS], 2889 .maxlen = sizeof(int), 2890 .mode = 0444, 2891 .proc_handler = do_proc_dqstats, 2892 }, 2893 { 2894 .procname = "writes", 2895 .data = &dqstats.stat[DQST_WRITES], 2896 .maxlen = sizeof(int), 2897 .mode = 0444, 2898 .proc_handler = do_proc_dqstats, 2899 }, 2900 { 2901 .procname = "cache_hits", 2902 .data = &dqstats.stat[DQST_CACHE_HITS], 2903 .maxlen = sizeof(int), 2904 .mode = 0444, 2905 .proc_handler = do_proc_dqstats, 2906 }, 2907 { 2908 .procname = "allocated_dquots", 2909 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2910 .maxlen = sizeof(int), 2911 .mode = 0444, 2912 .proc_handler = do_proc_dqstats, 2913 }, 2914 { 2915 .procname = "free_dquots", 2916 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2917 .maxlen = sizeof(int), 2918 .mode = 0444, 2919 .proc_handler = do_proc_dqstats, 2920 }, 2921 { 2922 .procname = "syncs", 2923 .data = &dqstats.stat[DQST_SYNCS], 2924 .maxlen = sizeof(int), 2925 .mode = 0444, 2926 .proc_handler = do_proc_dqstats, 2927 }, 2928 #ifdef CONFIG_PRINT_QUOTA_WARNING 2929 { 2930 .procname = "warnings", 2931 .data = &flag_print_warnings, 2932 .maxlen = sizeof(int), 2933 .mode = 0644, 2934 .proc_handler = proc_dointvec, 2935 }, 2936 #endif 2937 { }, 2938 }; 2939 2940 static struct ctl_table fs_table[] = { 2941 { 2942 .procname = "quota", 2943 .mode = 0555, 2944 .child = fs_dqstats_table, 2945 }, 2946 { }, 2947 }; 2948 2949 static struct ctl_table sys_table[] = { 2950 { 2951 .procname = "fs", 2952 .mode = 0555, 2953 .child = fs_table, 2954 }, 2955 { }, 2956 }; 2957 2958 static int __init dquot_init(void) 2959 { 2960 int i, ret; 2961 unsigned long nr_hash, order; 2962 2963 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2964 2965 register_sysctl_table(sys_table); 2966 2967 dquot_cachep = kmem_cache_create("dquot", 2968 sizeof(struct dquot), sizeof(unsigned long) * 4, 2969 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2970 SLAB_MEM_SPREAD|SLAB_PANIC), 2971 NULL); 2972 2973 order = 0; 2974 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2975 if (!dquot_hash) 2976 panic("Cannot create dquot hash table"); 2977 2978 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2979 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2980 if (ret) 2981 panic("Cannot create dquot stat counters"); 2982 } 2983 2984 /* Find power-of-two hlist_heads which can fit into allocation */ 2985 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2986 dq_hash_bits = 0; 2987 do { 2988 dq_hash_bits++; 2989 } while (nr_hash >> dq_hash_bits); 2990 dq_hash_bits--; 2991 2992 nr_hash = 1UL << dq_hash_bits; 2993 dq_hash_mask = nr_hash - 1; 2994 for (i = 0; i < nr_hash; i++) 2995 INIT_HLIST_HEAD(dquot_hash + i); 2996 2997 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2998 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2999 3000 if (register_shrinker(&dqcache_shrinker)) 3001 panic("Cannot register dquot shrinker"); 3002 3003 return 0; 3004 } 3005 fs_initcall(dquot_init); 3006