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 <linux/blkdev.h> 82 #include "../internal.h" /* ugh */ 83 84 #include <linux/uaccess.h> 85 86 /* 87 * There are five quota SMP locks: 88 * * dq_list_lock protects all lists with quotas and quota formats. 89 * * dquot->dq_dqb_lock protects data from dq_dqb 90 * * inode->i_lock protects inode->i_blocks, i_bytes and also guards 91 * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that 92 * dquot_transfer() can stabilize amount it transfers 93 * * dq_data_lock protects mem_dqinfo structures and modifications of dquot 94 * pointers in the inode 95 * * dq_state_lock protects modifications of quota state (on quotaon and 96 * quotaoff) and readers who care about latest values take it as well. 97 * 98 * The spinlock ordering is hence: 99 * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, 100 * dq_list_lock > dq_state_lock 101 * 102 * Note that some things (eg. sb pointer, type, id) doesn't change during 103 * the life of the dquot structure and so needn't to be protected by a lock 104 * 105 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 106 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 107 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 108 * inode and before dropping dquot references to avoid use of dquots after 109 * they are freed. dq_data_lock is used to serialize the pointer setting and 110 * clearing operations. 111 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 112 * inode is a quota file). Functions adding pointers from inode to dquots have 113 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 114 * have to do all pointer modifications before dropping dq_data_lock. This makes 115 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 116 * then drops all pointers to dquots from an inode. 117 * 118 * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to 119 * memory (or space for it is being allocated) on the first dqget(), when it is 120 * being written out, and when it is being released on the last dqput(). The 121 * allocation and release operations are serialized by the dq_lock and by 122 * checking the use count in dquot_release(). 123 * 124 * Lock ordering (including related VFS locks) is the following: 125 * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem 126 */ 127 128 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 129 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 130 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 131 EXPORT_SYMBOL(dq_data_lock); 132 DEFINE_STATIC_SRCU(dquot_srcu); 133 134 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); 135 136 void __quota_error(struct super_block *sb, const char *func, 137 const char *fmt, ...) 138 { 139 if (printk_ratelimit()) { 140 va_list args; 141 struct va_format vaf; 142 143 va_start(args, fmt); 144 145 vaf.fmt = fmt; 146 vaf.va = &args; 147 148 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 149 sb->s_id, func, &vaf); 150 151 va_end(args); 152 } 153 } 154 EXPORT_SYMBOL(__quota_error); 155 156 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 157 static char *quotatypes[] = INITQFNAMES; 158 #endif 159 static struct quota_format_type *quota_formats; /* List of registered formats */ 160 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 161 162 /* SLAB cache for dquot structures */ 163 static struct kmem_cache *dquot_cachep; 164 165 int register_quota_format(struct quota_format_type *fmt) 166 { 167 spin_lock(&dq_list_lock); 168 fmt->qf_next = quota_formats; 169 quota_formats = fmt; 170 spin_unlock(&dq_list_lock); 171 return 0; 172 } 173 EXPORT_SYMBOL(register_quota_format); 174 175 void unregister_quota_format(struct quota_format_type *fmt) 176 { 177 struct quota_format_type **actqf; 178 179 spin_lock(&dq_list_lock); 180 for (actqf = "a_formats; *actqf && *actqf != fmt; 181 actqf = &(*actqf)->qf_next) 182 ; 183 if (*actqf) 184 *actqf = (*actqf)->qf_next; 185 spin_unlock(&dq_list_lock); 186 } 187 EXPORT_SYMBOL(unregister_quota_format); 188 189 static struct quota_format_type *find_quota_format(int id) 190 { 191 struct quota_format_type *actqf; 192 193 spin_lock(&dq_list_lock); 194 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 195 actqf = actqf->qf_next) 196 ; 197 if (!actqf || !try_module_get(actqf->qf_owner)) { 198 int qm; 199 200 spin_unlock(&dq_list_lock); 201 202 for (qm = 0; module_names[qm].qm_fmt_id && 203 module_names[qm].qm_fmt_id != id; qm++) 204 ; 205 if (!module_names[qm].qm_fmt_id || 206 request_module(module_names[qm].qm_mod_name)) 207 return NULL; 208 209 spin_lock(&dq_list_lock); 210 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 211 actqf = actqf->qf_next) 212 ; 213 if (actqf && !try_module_get(actqf->qf_owner)) 214 actqf = NULL; 215 } 216 spin_unlock(&dq_list_lock); 217 return actqf; 218 } 219 220 static void put_quota_format(struct quota_format_type *fmt) 221 { 222 module_put(fmt->qf_owner); 223 } 224 225 /* 226 * Dquot List Management: 227 * The quota code uses four lists for dquot management: the inuse_list, 228 * free_dquots, dqi_dirty_list, and dquot_hash[] array. A single dquot 229 * structure may be on some of those lists, depending on its current state. 230 * 231 * All dquots are placed to the end of inuse_list when first created, and this 232 * list is used for invalidate operation, which must look at every dquot. 233 * 234 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 235 * and this list is searched whenever we need an available dquot. Dquots are 236 * removed from the list as soon as they are used again, and 237 * dqstats.free_dquots gives the number of dquots on the list. When 238 * dquot is invalidated it's completely released from memory. 239 * 240 * Dirty dquots are added to the dqi_dirty_list of quota_info when mark 241 * dirtied, and this list is searched when writing dirty dquots back to 242 * quota file. Note that some filesystems do dirty dquot tracking on their 243 * own (e.g. in a journal) and thus don't use dqi_dirty_list. 244 * 245 * Dquots with a specific identity (device, type and id) are placed on 246 * one of the dquot_hash[] hash chains. The provides an efficient search 247 * mechanism to locate a specific dquot. 248 */ 249 250 static LIST_HEAD(inuse_list); 251 static LIST_HEAD(free_dquots); 252 static unsigned int dq_hash_bits, dq_hash_mask; 253 static struct hlist_head *dquot_hash; 254 255 struct dqstats dqstats; 256 EXPORT_SYMBOL(dqstats); 257 258 static qsize_t inode_get_rsv_space(struct inode *inode); 259 static qsize_t __inode_get_rsv_space(struct inode *inode); 260 static int __dquot_initialize(struct inode *inode, int type); 261 262 static inline unsigned int 263 hashfn(const struct super_block *sb, struct kqid qid) 264 { 265 unsigned int id = from_kqid(&init_user_ns, qid); 266 int type = qid.type; 267 unsigned long tmp; 268 269 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 270 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 271 } 272 273 /* 274 * Following list functions expect dq_list_lock to be held 275 */ 276 static inline void insert_dquot_hash(struct dquot *dquot) 277 { 278 struct hlist_head *head; 279 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 280 hlist_add_head(&dquot->dq_hash, head); 281 } 282 283 static inline void remove_dquot_hash(struct dquot *dquot) 284 { 285 hlist_del_init(&dquot->dq_hash); 286 } 287 288 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 289 struct kqid qid) 290 { 291 struct hlist_node *node; 292 struct dquot *dquot; 293 294 hlist_for_each (node, dquot_hash+hashent) { 295 dquot = hlist_entry(node, struct dquot, dq_hash); 296 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 297 return dquot; 298 } 299 return NULL; 300 } 301 302 /* Add a dquot to the tail of the free list */ 303 static inline void put_dquot_last(struct dquot *dquot) 304 { 305 list_add_tail(&dquot->dq_free, &free_dquots); 306 dqstats_inc(DQST_FREE_DQUOTS); 307 } 308 309 static inline void remove_free_dquot(struct dquot *dquot) 310 { 311 if (list_empty(&dquot->dq_free)) 312 return; 313 list_del_init(&dquot->dq_free); 314 dqstats_dec(DQST_FREE_DQUOTS); 315 } 316 317 static inline void put_inuse(struct dquot *dquot) 318 { 319 /* We add to the back of inuse list so we don't have to restart 320 * when traversing this list and we block */ 321 list_add_tail(&dquot->dq_inuse, &inuse_list); 322 dqstats_inc(DQST_ALLOC_DQUOTS); 323 } 324 325 static inline void remove_inuse(struct dquot *dquot) 326 { 327 dqstats_dec(DQST_ALLOC_DQUOTS); 328 list_del(&dquot->dq_inuse); 329 } 330 /* 331 * End of list functions needing dq_list_lock 332 */ 333 334 static void wait_on_dquot(struct dquot *dquot) 335 { 336 mutex_lock(&dquot->dq_lock); 337 mutex_unlock(&dquot->dq_lock); 338 } 339 340 static inline int dquot_dirty(struct dquot *dquot) 341 { 342 return test_bit(DQ_MOD_B, &dquot->dq_flags); 343 } 344 345 static inline int mark_dquot_dirty(struct dquot *dquot) 346 { 347 return dquot->dq_sb->dq_op->mark_dirty(dquot); 348 } 349 350 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 351 int dquot_mark_dquot_dirty(struct dquot *dquot) 352 { 353 int ret = 1; 354 355 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 356 return 0; 357 358 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 359 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 360 361 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 362 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 363 return 1; 364 365 spin_lock(&dq_list_lock); 366 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 367 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 368 info[dquot->dq_id.type].dqi_dirty_list); 369 ret = 0; 370 } 371 spin_unlock(&dq_list_lock); 372 return ret; 373 } 374 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 375 376 /* Dirtify all the dquots - this can block when journalling */ 377 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 378 { 379 int ret, err, cnt; 380 381 ret = err = 0; 382 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 383 if (dquot[cnt]) 384 /* Even in case of error we have to continue */ 385 ret = mark_dquot_dirty(dquot[cnt]); 386 if (!err) 387 err = ret; 388 } 389 return err; 390 } 391 392 static inline void dqput_all(struct dquot **dquot) 393 { 394 unsigned int cnt; 395 396 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 397 dqput(dquot[cnt]); 398 } 399 400 static inline int clear_dquot_dirty(struct dquot *dquot) 401 { 402 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 403 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 404 405 spin_lock(&dq_list_lock); 406 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 407 spin_unlock(&dq_list_lock); 408 return 0; 409 } 410 list_del_init(&dquot->dq_dirty); 411 spin_unlock(&dq_list_lock); 412 return 1; 413 } 414 415 void mark_info_dirty(struct super_block *sb, int type) 416 { 417 spin_lock(&dq_data_lock); 418 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 419 spin_unlock(&dq_data_lock); 420 } 421 EXPORT_SYMBOL(mark_info_dirty); 422 423 /* 424 * Read dquot from disk and alloc space for it 425 */ 426 427 int dquot_acquire(struct dquot *dquot) 428 { 429 int ret = 0, ret2 = 0; 430 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 431 432 mutex_lock(&dquot->dq_lock); 433 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { 434 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 435 if (ret < 0) 436 goto out_iolock; 437 } 438 /* Make sure flags update is visible after dquot has been filled */ 439 smp_mb__before_atomic(); 440 set_bit(DQ_READ_B, &dquot->dq_flags); 441 /* Instantiate dquot if needed */ 442 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 443 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 444 /* Write the info if needed */ 445 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 446 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 447 dquot->dq_sb, dquot->dq_id.type); 448 } 449 if (ret < 0) 450 goto out_iolock; 451 if (ret2 < 0) { 452 ret = ret2; 453 goto out_iolock; 454 } 455 } 456 /* 457 * Make sure flags update is visible after on-disk struct has been 458 * allocated. Paired with smp_rmb() in dqget(). 459 */ 460 smp_mb__before_atomic(); 461 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 462 out_iolock: 463 mutex_unlock(&dquot->dq_lock); 464 return ret; 465 } 466 EXPORT_SYMBOL(dquot_acquire); 467 468 /* 469 * Write dquot to disk 470 */ 471 int dquot_commit(struct dquot *dquot) 472 { 473 int ret = 0; 474 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 475 476 mutex_lock(&dquot->dq_lock); 477 if (!clear_dquot_dirty(dquot)) 478 goto out_lock; 479 /* Inactive dquot can be only if there was error during read/init 480 * => we have better not writing it */ 481 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 482 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 483 else 484 ret = -EIO; 485 out_lock: 486 mutex_unlock(&dquot->dq_lock); 487 return ret; 488 } 489 EXPORT_SYMBOL(dquot_commit); 490 491 /* 492 * Release dquot 493 */ 494 int dquot_release(struct dquot *dquot) 495 { 496 int ret = 0, ret2 = 0; 497 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 498 499 mutex_lock(&dquot->dq_lock); 500 /* Check whether we are not racing with some other dqget() */ 501 if (dquot_is_busy(dquot)) 502 goto out_dqlock; 503 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 504 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 505 /* Write the info */ 506 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 507 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 508 dquot->dq_sb, dquot->dq_id.type); 509 } 510 if (ret >= 0) 511 ret = ret2; 512 } 513 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 514 out_dqlock: 515 mutex_unlock(&dquot->dq_lock); 516 return ret; 517 } 518 EXPORT_SYMBOL(dquot_release); 519 520 void dquot_destroy(struct dquot *dquot) 521 { 522 kmem_cache_free(dquot_cachep, dquot); 523 } 524 EXPORT_SYMBOL(dquot_destroy); 525 526 static inline void do_destroy_dquot(struct dquot *dquot) 527 { 528 dquot->dq_sb->dq_op->destroy_dquot(dquot); 529 } 530 531 /* Invalidate all dquots on the list. Note that this function is called after 532 * quota is disabled and pointers from inodes removed so there cannot be new 533 * quota users. There can still be some users of quotas due to inodes being 534 * just deleted or pruned by prune_icache() (those are not attached to any 535 * list) or parallel quotactl call. We have to wait for such users. 536 */ 537 static void invalidate_dquots(struct super_block *sb, int type) 538 { 539 struct dquot *dquot, *tmp; 540 541 restart: 542 spin_lock(&dq_list_lock); 543 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 544 if (dquot->dq_sb != sb) 545 continue; 546 if (dquot->dq_id.type != type) 547 continue; 548 /* Wait for dquot users */ 549 if (atomic_read(&dquot->dq_count)) { 550 dqgrab(dquot); 551 spin_unlock(&dq_list_lock); 552 /* 553 * Once dqput() wakes us up, we know it's time to free 554 * the dquot. 555 * IMPORTANT: we rely on the fact that there is always 556 * at most one process waiting for dquot to free. 557 * Otherwise dq_count would be > 1 and we would never 558 * wake up. 559 */ 560 wait_event(dquot_ref_wq, 561 atomic_read(&dquot->dq_count) == 1); 562 dqput(dquot); 563 /* At this moment dquot() need not exist (it could be 564 * reclaimed by prune_dqcache(). Hence we must 565 * restart. */ 566 goto restart; 567 } 568 /* 569 * Quota now has no users and it has been written on last 570 * dqput() 571 */ 572 remove_dquot_hash(dquot); 573 remove_free_dquot(dquot); 574 remove_inuse(dquot); 575 do_destroy_dquot(dquot); 576 } 577 spin_unlock(&dq_list_lock); 578 } 579 580 /* Call callback for every active dquot on given filesystem */ 581 int dquot_scan_active(struct super_block *sb, 582 int (*fn)(struct dquot *dquot, unsigned long priv), 583 unsigned long priv) 584 { 585 struct dquot *dquot, *old_dquot = NULL; 586 int ret = 0; 587 588 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 589 590 spin_lock(&dq_list_lock); 591 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 592 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 593 continue; 594 if (dquot->dq_sb != sb) 595 continue; 596 /* Now we have active dquot so we can just increase use count */ 597 atomic_inc(&dquot->dq_count); 598 spin_unlock(&dq_list_lock); 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 /* Move list away to avoid livelock. */ 641 list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty); 642 while (!list_empty(&dirty)) { 643 dquot = list_first_entry(&dirty, struct dquot, 644 dq_dirty); 645 646 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 647 648 /* Now we have active dquot from which someone is 649 * holding reference so we can safely just increase 650 * use count */ 651 dqgrab(dquot); 652 spin_unlock(&dq_list_lock); 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 cond_resched(); 989 spin_lock(&sb->s_inode_list_lock); 990 } 991 spin_unlock(&sb->s_inode_list_lock); 992 iput(old_inode); 993 out: 994 #ifdef CONFIG_QUOTA_DEBUG 995 if (reserved) { 996 quota_error(sb, "Writes happened before quota was turned on " 997 "thus quota information is probably inconsistent. " 998 "Please run quotacheck(8)"); 999 } 1000 #endif 1001 return err; 1002 } 1003 1004 /* 1005 * Remove references to dquots from inode and add dquot to list for freeing 1006 * if we have the last reference to dquot 1007 */ 1008 static void remove_inode_dquot_ref(struct inode *inode, int type, 1009 struct list_head *tofree_head) 1010 { 1011 struct dquot **dquots = i_dquot(inode); 1012 struct dquot *dquot = dquots[type]; 1013 1014 if (!dquot) 1015 return; 1016 1017 dquots[type] = NULL; 1018 if (list_empty(&dquot->dq_free)) { 1019 /* 1020 * The inode still has reference to dquot so it can't be in the 1021 * free list 1022 */ 1023 spin_lock(&dq_list_lock); 1024 list_add(&dquot->dq_free, tofree_head); 1025 spin_unlock(&dq_list_lock); 1026 } else { 1027 /* 1028 * Dquot is already in a list to put so we won't drop the last 1029 * reference here. 1030 */ 1031 dqput(dquot); 1032 } 1033 } 1034 1035 /* 1036 * Free list of dquots 1037 * Dquots are removed from inodes and no new references can be got so we are 1038 * the only ones holding reference 1039 */ 1040 static void put_dquot_list(struct list_head *tofree_head) 1041 { 1042 struct list_head *act_head; 1043 struct dquot *dquot; 1044 1045 act_head = tofree_head->next; 1046 while (act_head != tofree_head) { 1047 dquot = list_entry(act_head, struct dquot, dq_free); 1048 act_head = act_head->next; 1049 /* Remove dquot from the list so we won't have problems... */ 1050 list_del_init(&dquot->dq_free); 1051 dqput(dquot); 1052 } 1053 } 1054 1055 static void remove_dquot_ref(struct super_block *sb, int type, 1056 struct list_head *tofree_head) 1057 { 1058 struct inode *inode; 1059 #ifdef CONFIG_QUOTA_DEBUG 1060 int reserved = 0; 1061 #endif 1062 1063 spin_lock(&sb->s_inode_list_lock); 1064 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1065 /* 1066 * We have to scan also I_NEW inodes because they can already 1067 * have quota pointer initialized. Luckily, we need to touch 1068 * only quota pointers and these have separate locking 1069 * (dq_data_lock). 1070 */ 1071 spin_lock(&dq_data_lock); 1072 if (!IS_NOQUOTA(inode)) { 1073 #ifdef CONFIG_QUOTA_DEBUG 1074 if (unlikely(inode_get_rsv_space(inode) > 0)) 1075 reserved = 1; 1076 #endif 1077 remove_inode_dquot_ref(inode, type, tofree_head); 1078 } 1079 spin_unlock(&dq_data_lock); 1080 } 1081 spin_unlock(&sb->s_inode_list_lock); 1082 #ifdef CONFIG_QUOTA_DEBUG 1083 if (reserved) { 1084 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1085 " was disabled thus quota information is probably " 1086 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1087 } 1088 #endif 1089 } 1090 1091 /* Gather all references from inodes and drop them */ 1092 static void drop_dquot_ref(struct super_block *sb, int type) 1093 { 1094 LIST_HEAD(tofree_head); 1095 1096 if (sb->dq_op) { 1097 remove_dquot_ref(sb, type, &tofree_head); 1098 synchronize_srcu(&dquot_srcu); 1099 put_dquot_list(&tofree_head); 1100 } 1101 } 1102 1103 static inline 1104 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1105 { 1106 if (dquot->dq_dqb.dqb_rsvspace >= number) 1107 dquot->dq_dqb.dqb_rsvspace -= number; 1108 else { 1109 WARN_ON_ONCE(1); 1110 dquot->dq_dqb.dqb_rsvspace = 0; 1111 } 1112 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1113 dquot->dq_dqb.dqb_bsoftlimit) 1114 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1115 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1116 } 1117 1118 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1119 { 1120 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1121 dquot->dq_dqb.dqb_curinodes >= number) 1122 dquot->dq_dqb.dqb_curinodes -= number; 1123 else 1124 dquot->dq_dqb.dqb_curinodes = 0; 1125 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1126 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1127 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1128 } 1129 1130 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1131 { 1132 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1133 dquot->dq_dqb.dqb_curspace >= number) 1134 dquot->dq_dqb.dqb_curspace -= number; 1135 else 1136 dquot->dq_dqb.dqb_curspace = 0; 1137 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1138 dquot->dq_dqb.dqb_bsoftlimit) 1139 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1140 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1141 } 1142 1143 struct dquot_warn { 1144 struct super_block *w_sb; 1145 struct kqid w_dq_id; 1146 short w_type; 1147 }; 1148 1149 static int warning_issued(struct dquot *dquot, const int warntype) 1150 { 1151 int flag = (warntype == QUOTA_NL_BHARDWARN || 1152 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1153 ((warntype == QUOTA_NL_IHARDWARN || 1154 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1155 1156 if (!flag) 1157 return 0; 1158 return test_and_set_bit(flag, &dquot->dq_flags); 1159 } 1160 1161 #ifdef CONFIG_PRINT_QUOTA_WARNING 1162 static int flag_print_warnings = 1; 1163 1164 static int need_print_warning(struct dquot_warn *warn) 1165 { 1166 if (!flag_print_warnings) 1167 return 0; 1168 1169 switch (warn->w_dq_id.type) { 1170 case USRQUOTA: 1171 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1172 case GRPQUOTA: 1173 return in_group_p(warn->w_dq_id.gid); 1174 case PRJQUOTA: 1175 return 1; 1176 } 1177 return 0; 1178 } 1179 1180 /* Print warning to user which exceeded quota */ 1181 static void print_warning(struct dquot_warn *warn) 1182 { 1183 char *msg = NULL; 1184 struct tty_struct *tty; 1185 int warntype = warn->w_type; 1186 1187 if (warntype == QUOTA_NL_IHARDBELOW || 1188 warntype == QUOTA_NL_ISOFTBELOW || 1189 warntype == QUOTA_NL_BHARDBELOW || 1190 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1191 return; 1192 1193 tty = get_current_tty(); 1194 if (!tty) 1195 return; 1196 tty_write_message(tty, warn->w_sb->s_id); 1197 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1198 tty_write_message(tty, ": warning, "); 1199 else 1200 tty_write_message(tty, ": write failed, "); 1201 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1202 switch (warntype) { 1203 case QUOTA_NL_IHARDWARN: 1204 msg = " file limit reached.\r\n"; 1205 break; 1206 case QUOTA_NL_ISOFTLONGWARN: 1207 msg = " file quota exceeded too long.\r\n"; 1208 break; 1209 case QUOTA_NL_ISOFTWARN: 1210 msg = " file quota exceeded.\r\n"; 1211 break; 1212 case QUOTA_NL_BHARDWARN: 1213 msg = " block limit reached.\r\n"; 1214 break; 1215 case QUOTA_NL_BSOFTLONGWARN: 1216 msg = " block quota exceeded too long.\r\n"; 1217 break; 1218 case QUOTA_NL_BSOFTWARN: 1219 msg = " block quota exceeded.\r\n"; 1220 break; 1221 } 1222 tty_write_message(tty, msg); 1223 tty_kref_put(tty); 1224 } 1225 #endif 1226 1227 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1228 int warntype) 1229 { 1230 if (warning_issued(dquot, warntype)) 1231 return; 1232 warn->w_type = warntype; 1233 warn->w_sb = dquot->dq_sb; 1234 warn->w_dq_id = dquot->dq_id; 1235 } 1236 1237 /* 1238 * Write warnings to the console and send warning messages over netlink. 1239 * 1240 * Note that this function can call into tty and networking code. 1241 */ 1242 static void flush_warnings(struct dquot_warn *warn) 1243 { 1244 int i; 1245 1246 for (i = 0; i < MAXQUOTAS; i++) { 1247 if (warn[i].w_type == QUOTA_NL_NOWARN) 1248 continue; 1249 #ifdef CONFIG_PRINT_QUOTA_WARNING 1250 print_warning(&warn[i]); 1251 #endif 1252 quota_send_warning(warn[i].w_dq_id, 1253 warn[i].w_sb->s_dev, warn[i].w_type); 1254 } 1255 } 1256 1257 static int ignore_hardlimit(struct dquot *dquot) 1258 { 1259 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1260 1261 return capable(CAP_SYS_RESOURCE) && 1262 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1263 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1264 } 1265 1266 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1267 struct dquot_warn *warn) 1268 { 1269 qsize_t newinodes; 1270 int ret = 0; 1271 1272 spin_lock(&dquot->dq_dqb_lock); 1273 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1274 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1275 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1276 goto add; 1277 1278 if (dquot->dq_dqb.dqb_ihardlimit && 1279 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1280 !ignore_hardlimit(dquot)) { 1281 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1282 ret = -EDQUOT; 1283 goto out; 1284 } 1285 1286 if (dquot->dq_dqb.dqb_isoftlimit && 1287 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1288 dquot->dq_dqb.dqb_itime && 1289 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1290 !ignore_hardlimit(dquot)) { 1291 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1292 ret = -EDQUOT; 1293 goto out; 1294 } 1295 1296 if (dquot->dq_dqb.dqb_isoftlimit && 1297 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1298 dquot->dq_dqb.dqb_itime == 0) { 1299 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1300 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1301 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1302 } 1303 add: 1304 dquot->dq_dqb.dqb_curinodes = newinodes; 1305 1306 out: 1307 spin_unlock(&dquot->dq_dqb_lock); 1308 return ret; 1309 } 1310 1311 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1312 qsize_t rsv_space, unsigned int flags, 1313 struct dquot_warn *warn) 1314 { 1315 qsize_t tspace; 1316 struct super_block *sb = dquot->dq_sb; 1317 int ret = 0; 1318 1319 spin_lock(&dquot->dq_dqb_lock); 1320 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1321 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1322 goto finish; 1323 1324 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1325 + space + rsv_space; 1326 1327 if (dquot->dq_dqb.dqb_bhardlimit && 1328 tspace > dquot->dq_dqb.dqb_bhardlimit && 1329 !ignore_hardlimit(dquot)) { 1330 if (flags & DQUOT_SPACE_WARN) 1331 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 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 && 1339 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1340 !ignore_hardlimit(dquot)) { 1341 if (flags & DQUOT_SPACE_WARN) 1342 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1343 ret = -EDQUOT; 1344 goto finish; 1345 } 1346 1347 if (dquot->dq_dqb.dqb_bsoftlimit && 1348 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1349 dquot->dq_dqb.dqb_btime == 0) { 1350 if (flags & DQUOT_SPACE_WARN) { 1351 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1352 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1353 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1354 } else { 1355 /* 1356 * We don't allow preallocation to exceed softlimit so exceeding will 1357 * be always printed 1358 */ 1359 ret = -EDQUOT; 1360 goto finish; 1361 } 1362 } 1363 finish: 1364 /* 1365 * We have to be careful and go through warning generation & grace time 1366 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1367 * only here... 1368 */ 1369 if (flags & DQUOT_SPACE_NOFAIL) 1370 ret = 0; 1371 if (!ret) { 1372 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1373 dquot->dq_dqb.dqb_curspace += space; 1374 } 1375 spin_unlock(&dquot->dq_dqb_lock); 1376 return ret; 1377 } 1378 1379 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1380 { 1381 qsize_t newinodes; 1382 1383 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1384 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1385 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1386 return QUOTA_NL_NOWARN; 1387 1388 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1389 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1390 return QUOTA_NL_ISOFTBELOW; 1391 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1392 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1393 return QUOTA_NL_IHARDBELOW; 1394 return QUOTA_NL_NOWARN; 1395 } 1396 1397 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1398 { 1399 qsize_t tspace; 1400 1401 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1402 1403 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1404 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1405 return QUOTA_NL_NOWARN; 1406 1407 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1408 return QUOTA_NL_BSOFTBELOW; 1409 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1410 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1411 return QUOTA_NL_BHARDBELOW; 1412 return QUOTA_NL_NOWARN; 1413 } 1414 1415 static int dquot_active(const struct inode *inode) 1416 { 1417 struct super_block *sb = inode->i_sb; 1418 1419 if (IS_NOQUOTA(inode)) 1420 return 0; 1421 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1422 } 1423 1424 /* 1425 * Initialize quota pointers in inode 1426 * 1427 * It is better to call this function outside of any transaction as it 1428 * might need a lot of space in journal for dquot structure allocation. 1429 */ 1430 static int __dquot_initialize(struct inode *inode, int type) 1431 { 1432 int cnt, init_needed = 0; 1433 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1434 struct super_block *sb = inode->i_sb; 1435 qsize_t rsv; 1436 int ret = 0; 1437 1438 if (!dquot_active(inode)) 1439 return 0; 1440 1441 dquots = i_dquot(inode); 1442 1443 /* First get references to structures we might need. */ 1444 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1445 struct kqid qid; 1446 kprojid_t projid; 1447 int rc; 1448 struct dquot *dquot; 1449 1450 if (type != -1 && cnt != type) 1451 continue; 1452 /* 1453 * The i_dquot should have been initialized in most cases, 1454 * we check it without locking here to avoid unnecessary 1455 * dqget()/dqput() calls. 1456 */ 1457 if (dquots[cnt]) 1458 continue; 1459 1460 if (!sb_has_quota_active(sb, cnt)) 1461 continue; 1462 1463 init_needed = 1; 1464 1465 switch (cnt) { 1466 case USRQUOTA: 1467 qid = make_kqid_uid(inode->i_uid); 1468 break; 1469 case GRPQUOTA: 1470 qid = make_kqid_gid(inode->i_gid); 1471 break; 1472 case PRJQUOTA: 1473 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1474 if (rc) 1475 continue; 1476 qid = make_kqid_projid(projid); 1477 break; 1478 } 1479 dquot = dqget(sb, qid); 1480 if (IS_ERR(dquot)) { 1481 /* We raced with somebody turning quotas off... */ 1482 if (PTR_ERR(dquot) != -ESRCH) { 1483 ret = PTR_ERR(dquot); 1484 goto out_put; 1485 } 1486 dquot = NULL; 1487 } 1488 got[cnt] = dquot; 1489 } 1490 1491 /* All required i_dquot has been initialized */ 1492 if (!init_needed) 1493 return 0; 1494 1495 spin_lock(&dq_data_lock); 1496 if (IS_NOQUOTA(inode)) 1497 goto out_lock; 1498 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1499 if (type != -1 && cnt != type) 1500 continue; 1501 /* Avoid races with quotaoff() */ 1502 if (!sb_has_quota_active(sb, cnt)) 1503 continue; 1504 /* We could race with quotaon or dqget() could have failed */ 1505 if (!got[cnt]) 1506 continue; 1507 if (!dquots[cnt]) { 1508 dquots[cnt] = got[cnt]; 1509 got[cnt] = NULL; 1510 /* 1511 * Make quota reservation system happy if someone 1512 * did a write before quota was turned on 1513 */ 1514 rsv = inode_get_rsv_space(inode); 1515 if (unlikely(rsv)) { 1516 spin_lock(&inode->i_lock); 1517 /* Get reservation again under proper lock */ 1518 rsv = __inode_get_rsv_space(inode); 1519 spin_lock(&dquots[cnt]->dq_dqb_lock); 1520 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1521 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1522 spin_unlock(&inode->i_lock); 1523 } 1524 } 1525 } 1526 out_lock: 1527 spin_unlock(&dq_data_lock); 1528 out_put: 1529 /* Drop unused references */ 1530 dqput_all(got); 1531 1532 return ret; 1533 } 1534 1535 int dquot_initialize(struct inode *inode) 1536 { 1537 return __dquot_initialize(inode, -1); 1538 } 1539 EXPORT_SYMBOL(dquot_initialize); 1540 1541 bool dquot_initialize_needed(struct inode *inode) 1542 { 1543 struct dquot **dquots; 1544 int i; 1545 1546 if (!dquot_active(inode)) 1547 return false; 1548 1549 dquots = i_dquot(inode); 1550 for (i = 0; i < MAXQUOTAS; i++) 1551 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1552 return true; 1553 return false; 1554 } 1555 EXPORT_SYMBOL(dquot_initialize_needed); 1556 1557 /* 1558 * Release all quotas referenced by inode. 1559 * 1560 * This function only be called on inode free or converting 1561 * a file to quota file, no other users for the i_dquot in 1562 * both cases, so we needn't call synchronize_srcu() after 1563 * clearing i_dquot. 1564 */ 1565 static void __dquot_drop(struct inode *inode) 1566 { 1567 int cnt; 1568 struct dquot **dquots = i_dquot(inode); 1569 struct dquot *put[MAXQUOTAS]; 1570 1571 spin_lock(&dq_data_lock); 1572 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1573 put[cnt] = dquots[cnt]; 1574 dquots[cnt] = NULL; 1575 } 1576 spin_unlock(&dq_data_lock); 1577 dqput_all(put); 1578 } 1579 1580 void dquot_drop(struct inode *inode) 1581 { 1582 struct dquot * const *dquots; 1583 int cnt; 1584 1585 if (IS_NOQUOTA(inode)) 1586 return; 1587 1588 /* 1589 * Test before calling to rule out calls from proc and such 1590 * where we are not allowed to block. Note that this is 1591 * actually reliable test even without the lock - the caller 1592 * must assure that nobody can come after the DQUOT_DROP and 1593 * add quota pointers back anyway. 1594 */ 1595 dquots = i_dquot(inode); 1596 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1597 if (dquots[cnt]) 1598 break; 1599 } 1600 1601 if (cnt < MAXQUOTAS) 1602 __dquot_drop(inode); 1603 } 1604 EXPORT_SYMBOL(dquot_drop); 1605 1606 /* 1607 * inode_reserved_space is managed internally by quota, and protected by 1608 * i_lock similar to i_blocks+i_bytes. 1609 */ 1610 static qsize_t *inode_reserved_space(struct inode * inode) 1611 { 1612 /* Filesystem must explicitly define it's own method in order to use 1613 * quota reservation interface */ 1614 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1615 return inode->i_sb->dq_op->get_reserved_space(inode); 1616 } 1617 1618 static qsize_t __inode_get_rsv_space(struct inode *inode) 1619 { 1620 if (!inode->i_sb->dq_op->get_reserved_space) 1621 return 0; 1622 return *inode_reserved_space(inode); 1623 } 1624 1625 static qsize_t inode_get_rsv_space(struct inode *inode) 1626 { 1627 qsize_t ret; 1628 1629 if (!inode->i_sb->dq_op->get_reserved_space) 1630 return 0; 1631 spin_lock(&inode->i_lock); 1632 ret = __inode_get_rsv_space(inode); 1633 spin_unlock(&inode->i_lock); 1634 return ret; 1635 } 1636 1637 /* 1638 * This functions updates i_blocks+i_bytes fields and quota information 1639 * (together with appropriate checks). 1640 * 1641 * NOTE: We absolutely rely on the fact that caller dirties the inode 1642 * (usually helpers in quotaops.h care about this) and holds a handle for 1643 * the current transaction so that dquot write and inode write go into the 1644 * same transaction. 1645 */ 1646 1647 /* 1648 * This operation can block, but only after everything is updated 1649 */ 1650 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1651 { 1652 int cnt, ret = 0, index; 1653 struct dquot_warn warn[MAXQUOTAS]; 1654 int reserve = flags & DQUOT_SPACE_RESERVE; 1655 struct dquot **dquots; 1656 1657 if (!dquot_active(inode)) { 1658 if (reserve) { 1659 spin_lock(&inode->i_lock); 1660 *inode_reserved_space(inode) += number; 1661 spin_unlock(&inode->i_lock); 1662 } else { 1663 inode_add_bytes(inode, number); 1664 } 1665 goto out; 1666 } 1667 1668 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1669 warn[cnt].w_type = QUOTA_NL_NOWARN; 1670 1671 dquots = i_dquot(inode); 1672 index = srcu_read_lock(&dquot_srcu); 1673 spin_lock(&inode->i_lock); 1674 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1675 if (!dquots[cnt]) 1676 continue; 1677 if (reserve) { 1678 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1679 &warn[cnt]); 1680 } else { 1681 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1682 &warn[cnt]); 1683 } 1684 if (ret) { 1685 /* Back out changes we already did */ 1686 for (cnt--; cnt >= 0; cnt--) { 1687 if (!dquots[cnt]) 1688 continue; 1689 spin_lock(&dquots[cnt]->dq_dqb_lock); 1690 if (reserve) 1691 dquot_free_reserved_space(dquots[cnt], 1692 number); 1693 else 1694 dquot_decr_space(dquots[cnt], number); 1695 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1696 } 1697 spin_unlock(&inode->i_lock); 1698 goto out_flush_warn; 1699 } 1700 } 1701 if (reserve) 1702 *inode_reserved_space(inode) += number; 1703 else 1704 __inode_add_bytes(inode, number); 1705 spin_unlock(&inode->i_lock); 1706 1707 if (reserve) 1708 goto out_flush_warn; 1709 mark_all_dquot_dirty(dquots); 1710 out_flush_warn: 1711 srcu_read_unlock(&dquot_srcu, index); 1712 flush_warnings(warn); 1713 out: 1714 return ret; 1715 } 1716 EXPORT_SYMBOL(__dquot_alloc_space); 1717 1718 /* 1719 * This operation can block, but only after everything is updated 1720 */ 1721 int dquot_alloc_inode(struct inode *inode) 1722 { 1723 int cnt, ret = 0, index; 1724 struct dquot_warn warn[MAXQUOTAS]; 1725 struct dquot * const *dquots; 1726 1727 if (!dquot_active(inode)) 1728 return 0; 1729 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1730 warn[cnt].w_type = QUOTA_NL_NOWARN; 1731 1732 dquots = i_dquot(inode); 1733 index = srcu_read_lock(&dquot_srcu); 1734 spin_lock(&inode->i_lock); 1735 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1736 if (!dquots[cnt]) 1737 continue; 1738 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1739 if (ret) { 1740 for (cnt--; cnt >= 0; cnt--) { 1741 if (!dquots[cnt]) 1742 continue; 1743 /* Back out changes we already did */ 1744 spin_lock(&dquots[cnt]->dq_dqb_lock); 1745 dquot_decr_inodes(dquots[cnt], 1); 1746 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1747 } 1748 goto warn_put_all; 1749 } 1750 } 1751 1752 warn_put_all: 1753 spin_unlock(&inode->i_lock); 1754 if (ret == 0) 1755 mark_all_dquot_dirty(dquots); 1756 srcu_read_unlock(&dquot_srcu, index); 1757 flush_warnings(warn); 1758 return ret; 1759 } 1760 EXPORT_SYMBOL(dquot_alloc_inode); 1761 1762 /* 1763 * Convert in-memory reserved quotas to real consumed quotas 1764 */ 1765 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1766 { 1767 struct dquot **dquots; 1768 int cnt, index; 1769 1770 if (!dquot_active(inode)) { 1771 spin_lock(&inode->i_lock); 1772 *inode_reserved_space(inode) -= number; 1773 __inode_add_bytes(inode, number); 1774 spin_unlock(&inode->i_lock); 1775 return 0; 1776 } 1777 1778 dquots = i_dquot(inode); 1779 index = srcu_read_lock(&dquot_srcu); 1780 spin_lock(&inode->i_lock); 1781 /* Claim reserved quotas to allocated quotas */ 1782 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1783 if (dquots[cnt]) { 1784 struct dquot *dquot = dquots[cnt]; 1785 1786 spin_lock(&dquot->dq_dqb_lock); 1787 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1788 number = dquot->dq_dqb.dqb_rsvspace; 1789 dquot->dq_dqb.dqb_curspace += number; 1790 dquot->dq_dqb.dqb_rsvspace -= number; 1791 spin_unlock(&dquot->dq_dqb_lock); 1792 } 1793 } 1794 /* Update inode bytes */ 1795 *inode_reserved_space(inode) -= number; 1796 __inode_add_bytes(inode, number); 1797 spin_unlock(&inode->i_lock); 1798 mark_all_dquot_dirty(dquots); 1799 srcu_read_unlock(&dquot_srcu, index); 1800 return 0; 1801 } 1802 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1803 1804 /* 1805 * Convert allocated space back to in-memory reserved quotas 1806 */ 1807 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1808 { 1809 struct dquot **dquots; 1810 int cnt, index; 1811 1812 if (!dquot_active(inode)) { 1813 spin_lock(&inode->i_lock); 1814 *inode_reserved_space(inode) += number; 1815 __inode_sub_bytes(inode, number); 1816 spin_unlock(&inode->i_lock); 1817 return; 1818 } 1819 1820 dquots = i_dquot(inode); 1821 index = srcu_read_lock(&dquot_srcu); 1822 spin_lock(&inode->i_lock); 1823 /* Claim reserved quotas to allocated quotas */ 1824 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1825 if (dquots[cnt]) { 1826 struct dquot *dquot = dquots[cnt]; 1827 1828 spin_lock(&dquot->dq_dqb_lock); 1829 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1830 number = dquot->dq_dqb.dqb_curspace; 1831 dquot->dq_dqb.dqb_rsvspace += number; 1832 dquot->dq_dqb.dqb_curspace -= number; 1833 spin_unlock(&dquot->dq_dqb_lock); 1834 } 1835 } 1836 /* Update inode bytes */ 1837 *inode_reserved_space(inode) += number; 1838 __inode_sub_bytes(inode, number); 1839 spin_unlock(&inode->i_lock); 1840 mark_all_dquot_dirty(dquots); 1841 srcu_read_unlock(&dquot_srcu, index); 1842 return; 1843 } 1844 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1845 1846 /* 1847 * This operation can block, but only after everything is updated 1848 */ 1849 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1850 { 1851 unsigned int cnt; 1852 struct dquot_warn warn[MAXQUOTAS]; 1853 struct dquot **dquots; 1854 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1855 1856 if (!dquot_active(inode)) { 1857 if (reserve) { 1858 spin_lock(&inode->i_lock); 1859 *inode_reserved_space(inode) -= number; 1860 spin_unlock(&inode->i_lock); 1861 } else { 1862 inode_sub_bytes(inode, number); 1863 } 1864 return; 1865 } 1866 1867 dquots = i_dquot(inode); 1868 index = srcu_read_lock(&dquot_srcu); 1869 spin_lock(&inode->i_lock); 1870 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1871 int wtype; 1872 1873 warn[cnt].w_type = QUOTA_NL_NOWARN; 1874 if (!dquots[cnt]) 1875 continue; 1876 spin_lock(&dquots[cnt]->dq_dqb_lock); 1877 wtype = info_bdq_free(dquots[cnt], number); 1878 if (wtype != QUOTA_NL_NOWARN) 1879 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1880 if (reserve) 1881 dquot_free_reserved_space(dquots[cnt], number); 1882 else 1883 dquot_decr_space(dquots[cnt], number); 1884 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1885 } 1886 if (reserve) 1887 *inode_reserved_space(inode) -= number; 1888 else 1889 __inode_sub_bytes(inode, number); 1890 spin_unlock(&inode->i_lock); 1891 1892 if (reserve) 1893 goto out_unlock; 1894 mark_all_dquot_dirty(dquots); 1895 out_unlock: 1896 srcu_read_unlock(&dquot_srcu, index); 1897 flush_warnings(warn); 1898 } 1899 EXPORT_SYMBOL(__dquot_free_space); 1900 1901 /* 1902 * This operation can block, but only after everything is updated 1903 */ 1904 void dquot_free_inode(struct inode *inode) 1905 { 1906 unsigned int cnt; 1907 struct dquot_warn warn[MAXQUOTAS]; 1908 struct dquot * const *dquots; 1909 int index; 1910 1911 if (!dquot_active(inode)) 1912 return; 1913 1914 dquots = i_dquot(inode); 1915 index = srcu_read_lock(&dquot_srcu); 1916 spin_lock(&inode->i_lock); 1917 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1918 int wtype; 1919 1920 warn[cnt].w_type = QUOTA_NL_NOWARN; 1921 if (!dquots[cnt]) 1922 continue; 1923 spin_lock(&dquots[cnt]->dq_dqb_lock); 1924 wtype = info_idq_free(dquots[cnt], 1); 1925 if (wtype != QUOTA_NL_NOWARN) 1926 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1927 dquot_decr_inodes(dquots[cnt], 1); 1928 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1929 } 1930 spin_unlock(&inode->i_lock); 1931 mark_all_dquot_dirty(dquots); 1932 srcu_read_unlock(&dquot_srcu, index); 1933 flush_warnings(warn); 1934 } 1935 EXPORT_SYMBOL(dquot_free_inode); 1936 1937 /* 1938 * Transfer the number of inode and blocks from one diskquota to an other. 1939 * On success, dquot references in transfer_to are consumed and references 1940 * to original dquots that need to be released are placed there. On failure, 1941 * references are kept untouched. 1942 * 1943 * This operation can block, but only after everything is updated 1944 * A transaction must be started when entering this function. 1945 * 1946 * We are holding reference on transfer_from & transfer_to, no need to 1947 * protect them by srcu_read_lock(). 1948 */ 1949 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1950 { 1951 qsize_t cur_space; 1952 qsize_t rsv_space = 0; 1953 qsize_t inode_usage = 1; 1954 struct dquot *transfer_from[MAXQUOTAS] = {}; 1955 int cnt, ret = 0; 1956 char is_valid[MAXQUOTAS] = {}; 1957 struct dquot_warn warn_to[MAXQUOTAS]; 1958 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1959 struct dquot_warn warn_from_space[MAXQUOTAS]; 1960 1961 if (IS_NOQUOTA(inode)) 1962 return 0; 1963 1964 if (inode->i_sb->dq_op->get_inode_usage) { 1965 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1966 if (ret) 1967 return ret; 1968 } 1969 1970 /* Initialize the arrays */ 1971 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1972 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1973 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1974 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1975 } 1976 1977 spin_lock(&dq_data_lock); 1978 spin_lock(&inode->i_lock); 1979 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1980 spin_unlock(&inode->i_lock); 1981 spin_unlock(&dq_data_lock); 1982 return 0; 1983 } 1984 cur_space = __inode_get_bytes(inode); 1985 rsv_space = __inode_get_rsv_space(inode); 1986 /* 1987 * Build the transfer_from list, check limits, and update usage in 1988 * the target structures. 1989 */ 1990 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1991 /* 1992 * Skip changes for same uid or gid or for turned off quota-type. 1993 */ 1994 if (!transfer_to[cnt]) 1995 continue; 1996 /* Avoid races with quotaoff() */ 1997 if (!sb_has_quota_active(inode->i_sb, cnt)) 1998 continue; 1999 is_valid[cnt] = 1; 2000 transfer_from[cnt] = i_dquot(inode)[cnt]; 2001 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 2002 &warn_to[cnt]); 2003 if (ret) 2004 goto over_quota; 2005 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 2006 DQUOT_SPACE_WARN, &warn_to[cnt]); 2007 if (ret) { 2008 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2009 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2010 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2011 goto over_quota; 2012 } 2013 } 2014 2015 /* Decrease usage for source structures and update quota pointers */ 2016 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2017 if (!is_valid[cnt]) 2018 continue; 2019 /* Due to IO error we might not have transfer_from[] structure */ 2020 if (transfer_from[cnt]) { 2021 int wtype; 2022 2023 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2024 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2025 if (wtype != QUOTA_NL_NOWARN) 2026 prepare_warning(&warn_from_inodes[cnt], 2027 transfer_from[cnt], wtype); 2028 wtype = info_bdq_free(transfer_from[cnt], 2029 cur_space + rsv_space); 2030 if (wtype != QUOTA_NL_NOWARN) 2031 prepare_warning(&warn_from_space[cnt], 2032 transfer_from[cnt], wtype); 2033 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2034 dquot_decr_space(transfer_from[cnt], cur_space); 2035 dquot_free_reserved_space(transfer_from[cnt], 2036 rsv_space); 2037 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2038 } 2039 i_dquot(inode)[cnt] = transfer_to[cnt]; 2040 } 2041 spin_unlock(&inode->i_lock); 2042 spin_unlock(&dq_data_lock); 2043 2044 mark_all_dquot_dirty(transfer_from); 2045 mark_all_dquot_dirty(transfer_to); 2046 flush_warnings(warn_to); 2047 flush_warnings(warn_from_inodes); 2048 flush_warnings(warn_from_space); 2049 /* Pass back references to put */ 2050 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2051 if (is_valid[cnt]) 2052 transfer_to[cnt] = transfer_from[cnt]; 2053 return 0; 2054 over_quota: 2055 /* Back out changes we already did */ 2056 for (cnt--; cnt >= 0; cnt--) { 2057 if (!is_valid[cnt]) 2058 continue; 2059 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2060 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2061 dquot_decr_space(transfer_to[cnt], cur_space); 2062 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2063 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2064 } 2065 spin_unlock(&inode->i_lock); 2066 spin_unlock(&dq_data_lock); 2067 flush_warnings(warn_to); 2068 return ret; 2069 } 2070 EXPORT_SYMBOL(__dquot_transfer); 2071 2072 /* Wrapper for transferring ownership of an inode for uid/gid only 2073 * Called from FSXXX_setattr() 2074 */ 2075 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2076 { 2077 struct dquot *transfer_to[MAXQUOTAS] = {}; 2078 struct dquot *dquot; 2079 struct super_block *sb = inode->i_sb; 2080 int ret; 2081 2082 if (!dquot_active(inode)) 2083 return 0; 2084 2085 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2086 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2087 if (IS_ERR(dquot)) { 2088 if (PTR_ERR(dquot) != -ESRCH) { 2089 ret = PTR_ERR(dquot); 2090 goto out_put; 2091 } 2092 dquot = NULL; 2093 } 2094 transfer_to[USRQUOTA] = dquot; 2095 } 2096 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2097 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2098 if (IS_ERR(dquot)) { 2099 if (PTR_ERR(dquot) != -ESRCH) { 2100 ret = PTR_ERR(dquot); 2101 goto out_put; 2102 } 2103 dquot = NULL; 2104 } 2105 transfer_to[GRPQUOTA] = dquot; 2106 } 2107 ret = __dquot_transfer(inode, transfer_to); 2108 out_put: 2109 dqput_all(transfer_to); 2110 return ret; 2111 } 2112 EXPORT_SYMBOL(dquot_transfer); 2113 2114 /* 2115 * Write info of quota file to disk 2116 */ 2117 int dquot_commit_info(struct super_block *sb, int type) 2118 { 2119 struct quota_info *dqopt = sb_dqopt(sb); 2120 2121 return dqopt->ops[type]->write_file_info(sb, type); 2122 } 2123 EXPORT_SYMBOL(dquot_commit_info); 2124 2125 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2126 { 2127 struct quota_info *dqopt = sb_dqopt(sb); 2128 2129 if (!sb_has_quota_active(sb, qid->type)) 2130 return -ESRCH; 2131 if (!dqopt->ops[qid->type]->get_next_id) 2132 return -ENOSYS; 2133 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2134 } 2135 EXPORT_SYMBOL(dquot_get_next_id); 2136 2137 /* 2138 * Definitions of diskquota operations. 2139 */ 2140 const struct dquot_operations dquot_operations = { 2141 .write_dquot = dquot_commit, 2142 .acquire_dquot = dquot_acquire, 2143 .release_dquot = dquot_release, 2144 .mark_dirty = dquot_mark_dquot_dirty, 2145 .write_info = dquot_commit_info, 2146 .alloc_dquot = dquot_alloc, 2147 .destroy_dquot = dquot_destroy, 2148 .get_next_id = dquot_get_next_id, 2149 }; 2150 EXPORT_SYMBOL(dquot_operations); 2151 2152 /* 2153 * Generic helper for ->open on filesystems supporting disk quotas. 2154 */ 2155 int dquot_file_open(struct inode *inode, struct file *file) 2156 { 2157 int error; 2158 2159 error = generic_file_open(inode, file); 2160 if (!error && (file->f_mode & FMODE_WRITE)) 2161 error = dquot_initialize(inode); 2162 return error; 2163 } 2164 EXPORT_SYMBOL(dquot_file_open); 2165 2166 static void vfs_cleanup_quota_inode(struct super_block *sb, int type) 2167 { 2168 struct quota_info *dqopt = sb_dqopt(sb); 2169 struct inode *inode = dqopt->files[type]; 2170 2171 if (!inode) 2172 return; 2173 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2174 inode_lock(inode); 2175 inode->i_flags &= ~S_NOQUOTA; 2176 inode_unlock(inode); 2177 } 2178 dqopt->files[type] = NULL; 2179 iput(inode); 2180 } 2181 2182 /* 2183 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2184 */ 2185 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2186 { 2187 int cnt; 2188 struct quota_info *dqopt = sb_dqopt(sb); 2189 2190 /* s_umount should be held in exclusive mode */ 2191 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2192 up_read(&sb->s_umount); 2193 2194 /* Cannot turn off usage accounting without turning off limits, or 2195 * suspend quotas and simultaneously turn quotas off. */ 2196 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2197 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2198 DQUOT_USAGE_ENABLED))) 2199 return -EINVAL; 2200 2201 /* 2202 * Skip everything if there's nothing to do. We have to do this because 2203 * sometimes we are called when fill_super() failed and calling 2204 * sync_fs() in such cases does no good. 2205 */ 2206 if (!sb_any_quota_loaded(sb)) 2207 return 0; 2208 2209 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2210 if (type != -1 && cnt != type) 2211 continue; 2212 if (!sb_has_quota_loaded(sb, cnt)) 2213 continue; 2214 2215 if (flags & DQUOT_SUSPENDED) { 2216 spin_lock(&dq_state_lock); 2217 dqopt->flags |= 2218 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2219 spin_unlock(&dq_state_lock); 2220 } else { 2221 spin_lock(&dq_state_lock); 2222 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2223 /* Turning off suspended quotas? */ 2224 if (!sb_has_quota_loaded(sb, cnt) && 2225 sb_has_quota_suspended(sb, cnt)) { 2226 dqopt->flags &= ~dquot_state_flag( 2227 DQUOT_SUSPENDED, cnt); 2228 spin_unlock(&dq_state_lock); 2229 vfs_cleanup_quota_inode(sb, cnt); 2230 continue; 2231 } 2232 spin_unlock(&dq_state_lock); 2233 } 2234 2235 /* We still have to keep quota loaded? */ 2236 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2237 continue; 2238 2239 /* Note: these are blocking operations */ 2240 drop_dquot_ref(sb, cnt); 2241 invalidate_dquots(sb, cnt); 2242 /* 2243 * Now all dquots should be invalidated, all writes done so we 2244 * should be only users of the info. No locks needed. 2245 */ 2246 if (info_dirty(&dqopt->info[cnt])) 2247 sb->dq_op->write_info(sb, cnt); 2248 if (dqopt->ops[cnt]->free_file_info) 2249 dqopt->ops[cnt]->free_file_info(sb, cnt); 2250 put_quota_format(dqopt->info[cnt].dqi_format); 2251 dqopt->info[cnt].dqi_flags = 0; 2252 dqopt->info[cnt].dqi_igrace = 0; 2253 dqopt->info[cnt].dqi_bgrace = 0; 2254 dqopt->ops[cnt] = NULL; 2255 } 2256 2257 /* Skip syncing and setting flags if quota files are hidden */ 2258 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2259 goto put_inodes; 2260 2261 /* Sync the superblock so that buffers with quota data are written to 2262 * disk (and so userspace sees correct data afterwards). */ 2263 if (sb->s_op->sync_fs) 2264 sb->s_op->sync_fs(sb, 1); 2265 sync_blockdev(sb->s_bdev); 2266 /* Now the quota files are just ordinary files and we can set the 2267 * inode flags back. Moreover we discard the pagecache so that 2268 * userspace sees the writes we did bypassing the pagecache. We 2269 * must also discard the blockdev buffers so that we see the 2270 * changes done by userspace on the next quotaon() */ 2271 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2272 if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { 2273 inode_lock(dqopt->files[cnt]); 2274 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 2275 inode_unlock(dqopt->files[cnt]); 2276 } 2277 if (sb->s_bdev) 2278 invalidate_bdev(sb->s_bdev); 2279 put_inodes: 2280 /* We are done when suspending quotas */ 2281 if (flags & DQUOT_SUSPENDED) 2282 return 0; 2283 2284 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2285 if (!sb_has_quota_loaded(sb, cnt)) 2286 vfs_cleanup_quota_inode(sb, cnt); 2287 return 0; 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 static int vfs_setup_quota_inode(struct inode *inode, int type) 2303 { 2304 struct super_block *sb = inode->i_sb; 2305 struct quota_info *dqopt = sb_dqopt(sb); 2306 2307 if (!S_ISREG(inode->i_mode)) 2308 return -EACCES; 2309 if (IS_RDONLY(inode)) 2310 return -EROFS; 2311 if (sb_has_quota_loaded(sb, type)) 2312 return -EBUSY; 2313 2314 dqopt->files[type] = igrab(inode); 2315 if (!dqopt->files[type]) 2316 return -EIO; 2317 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2318 /* We don't want quota and atime on quota files (deadlocks 2319 * possible) Also nobody should write to the file - we use 2320 * special IO operations which ignore the immutable bit. */ 2321 inode_lock(inode); 2322 inode->i_flags |= S_NOQUOTA; 2323 inode_unlock(inode); 2324 /* 2325 * When S_NOQUOTA is set, remove dquot references as no more 2326 * references can be added 2327 */ 2328 __dquot_drop(inode); 2329 } 2330 return 0; 2331 } 2332 2333 int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, 2334 unsigned int flags) 2335 { 2336 struct quota_format_type *fmt = find_quota_format(format_id); 2337 struct quota_info *dqopt = sb_dqopt(sb); 2338 int error; 2339 2340 /* Just unsuspend quotas? */ 2341 BUG_ON(flags & DQUOT_SUSPENDED); 2342 /* s_umount should be held in exclusive mode */ 2343 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2344 up_read(&sb->s_umount); 2345 2346 if (!fmt) 2347 return -ESRCH; 2348 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2349 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2350 error = -EINVAL; 2351 goto out_fmt; 2352 } 2353 /* Filesystems outside of init_user_ns not yet supported */ 2354 if (sb->s_user_ns != &init_user_ns) { 2355 error = -EINVAL; 2356 goto out_fmt; 2357 } 2358 /* Usage always has to be set... */ 2359 if (!(flags & DQUOT_USAGE_ENABLED)) { 2360 error = -EINVAL; 2361 goto out_fmt; 2362 } 2363 if (sb_has_quota_loaded(sb, type)) { 2364 error = -EBUSY; 2365 goto out_fmt; 2366 } 2367 2368 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2369 /* As we bypass the pagecache we must now flush all the 2370 * dirty data and invalidate caches so that kernel sees 2371 * changes from userspace. It is not enough to just flush 2372 * the quota file since if blocksize < pagesize, invalidation 2373 * of the cache could fail because of other unrelated dirty 2374 * data */ 2375 sync_filesystem(sb); 2376 invalidate_bdev(sb->s_bdev); 2377 } 2378 2379 error = -EINVAL; 2380 if (!fmt->qf_ops->check_quota_file(sb, type)) 2381 goto out_fmt; 2382 2383 dqopt->ops[type] = fmt->qf_ops; 2384 dqopt->info[type].dqi_format = fmt; 2385 dqopt->info[type].dqi_fmt_id = format_id; 2386 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2387 error = dqopt->ops[type]->read_file_info(sb, type); 2388 if (error < 0) 2389 goto out_fmt; 2390 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2391 spin_lock(&dq_data_lock); 2392 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2393 spin_unlock(&dq_data_lock); 2394 } 2395 spin_lock(&dq_state_lock); 2396 dqopt->flags |= dquot_state_flag(flags, type); 2397 spin_unlock(&dq_state_lock); 2398 2399 error = add_dquot_ref(sb, type); 2400 if (error) 2401 dquot_disable(sb, type, flags); 2402 2403 return error; 2404 out_fmt: 2405 put_quota_format(fmt); 2406 2407 return error; 2408 } 2409 EXPORT_SYMBOL(dquot_load_quota_sb); 2410 2411 /* 2412 * More powerful function for turning on quotas on given quota inode allowing 2413 * setting of individual quota flags 2414 */ 2415 int dquot_load_quota_inode(struct inode *inode, int type, int format_id, 2416 unsigned int flags) 2417 { 2418 int err; 2419 2420 err = vfs_setup_quota_inode(inode, type); 2421 if (err < 0) 2422 return err; 2423 err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); 2424 if (err < 0) 2425 vfs_cleanup_quota_inode(inode->i_sb, type); 2426 return err; 2427 } 2428 EXPORT_SYMBOL(dquot_load_quota_inode); 2429 2430 /* Reenable quotas on remount RW */ 2431 int dquot_resume(struct super_block *sb, int type) 2432 { 2433 struct quota_info *dqopt = sb_dqopt(sb); 2434 int ret = 0, cnt; 2435 unsigned int flags; 2436 2437 /* s_umount should be held in exclusive mode */ 2438 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2439 up_read(&sb->s_umount); 2440 2441 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2442 if (type != -1 && cnt != type) 2443 continue; 2444 if (!sb_has_quota_suspended(sb, cnt)) 2445 continue; 2446 2447 spin_lock(&dq_state_lock); 2448 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2449 DQUOT_LIMITS_ENABLED, 2450 cnt); 2451 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2452 spin_unlock(&dq_state_lock); 2453 2454 flags = dquot_generic_flag(flags, cnt); 2455 ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, 2456 flags); 2457 if (ret < 0) 2458 vfs_cleanup_quota_inode(sb, type); 2459 } 2460 2461 return ret; 2462 } 2463 EXPORT_SYMBOL(dquot_resume); 2464 2465 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2466 const struct path *path) 2467 { 2468 int error = security_quota_on(path->dentry); 2469 if (error) 2470 return error; 2471 /* Quota file not on the same filesystem? */ 2472 if (path->dentry->d_sb != sb) 2473 error = -EXDEV; 2474 else 2475 error = dquot_load_quota_inode(d_inode(path->dentry), type, 2476 format_id, DQUOT_USAGE_ENABLED | 2477 DQUOT_LIMITS_ENABLED); 2478 return error; 2479 } 2480 EXPORT_SYMBOL(dquot_quota_on); 2481 2482 /* 2483 * This function is used when filesystem needs to initialize quotas 2484 * during mount time. 2485 */ 2486 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2487 int format_id, int type) 2488 { 2489 struct dentry *dentry; 2490 int error; 2491 2492 dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2493 if (IS_ERR(dentry)) 2494 return PTR_ERR(dentry); 2495 2496 error = security_quota_on(dentry); 2497 if (!error) 2498 error = dquot_load_quota_inode(d_inode(dentry), type, format_id, 2499 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2500 2501 dput(dentry); 2502 return error; 2503 } 2504 EXPORT_SYMBOL(dquot_quota_on_mount); 2505 2506 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2507 { 2508 int ret; 2509 int type; 2510 struct quota_info *dqopt = sb_dqopt(sb); 2511 2512 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2513 return -ENOSYS; 2514 /* Accounting cannot be turned on while fs is mounted */ 2515 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2516 if (!flags) 2517 return -EINVAL; 2518 for (type = 0; type < MAXQUOTAS; type++) { 2519 if (!(flags & qtype_enforce_flag(type))) 2520 continue; 2521 /* Can't enforce without accounting */ 2522 if (!sb_has_quota_usage_enabled(sb, type)) { 2523 ret = -EINVAL; 2524 goto out_err; 2525 } 2526 if (sb_has_quota_limits_enabled(sb, type)) { 2527 ret = -EBUSY; 2528 goto out_err; 2529 } 2530 spin_lock(&dq_state_lock); 2531 dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2532 spin_unlock(&dq_state_lock); 2533 } 2534 return 0; 2535 out_err: 2536 /* Backout enforcement enablement we already did */ 2537 for (type--; type >= 0; type--) { 2538 if (flags & qtype_enforce_flag(type)) 2539 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2540 } 2541 /* Error code translation for better compatibility with XFS */ 2542 if (ret == -EBUSY) 2543 ret = -EEXIST; 2544 return ret; 2545 } 2546 2547 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2548 { 2549 int ret; 2550 int type; 2551 struct quota_info *dqopt = sb_dqopt(sb); 2552 2553 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2554 return -ENOSYS; 2555 /* 2556 * We don't support turning off accounting via quotactl. In principle 2557 * quota infrastructure can do this but filesystems don't expect 2558 * userspace to be able to do it. 2559 */ 2560 if (flags & 2561 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2562 return -EOPNOTSUPP; 2563 2564 /* Filter out limits not enabled */ 2565 for (type = 0; type < MAXQUOTAS; type++) 2566 if (!sb_has_quota_limits_enabled(sb, type)) 2567 flags &= ~qtype_enforce_flag(type); 2568 /* Nothing left? */ 2569 if (!flags) 2570 return -EEXIST; 2571 for (type = 0; type < MAXQUOTAS; type++) { 2572 if (flags & qtype_enforce_flag(type)) { 2573 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2574 if (ret < 0) 2575 goto out_err; 2576 } 2577 } 2578 return 0; 2579 out_err: 2580 /* Backout enforcement disabling we already did */ 2581 for (type--; type >= 0; type--) { 2582 if (flags & qtype_enforce_flag(type)) { 2583 spin_lock(&dq_state_lock); 2584 dqopt->flags |= 2585 dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2586 spin_unlock(&dq_state_lock); 2587 } 2588 } 2589 return ret; 2590 } 2591 2592 /* Generic routine for getting common part of quota structure */ 2593 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2594 { 2595 struct mem_dqblk *dm = &dquot->dq_dqb; 2596 2597 memset(di, 0, sizeof(*di)); 2598 spin_lock(&dquot->dq_dqb_lock); 2599 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2600 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2601 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2602 di->d_ino_softlimit = dm->dqb_isoftlimit; 2603 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2604 di->d_ino_count = dm->dqb_curinodes; 2605 di->d_spc_timer = dm->dqb_btime; 2606 di->d_ino_timer = dm->dqb_itime; 2607 spin_unlock(&dquot->dq_dqb_lock); 2608 } 2609 2610 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2611 struct qc_dqblk *di) 2612 { 2613 struct dquot *dquot; 2614 2615 dquot = dqget(sb, qid); 2616 if (IS_ERR(dquot)) 2617 return PTR_ERR(dquot); 2618 do_get_dqblk(dquot, di); 2619 dqput(dquot); 2620 2621 return 0; 2622 } 2623 EXPORT_SYMBOL(dquot_get_dqblk); 2624 2625 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2626 struct qc_dqblk *di) 2627 { 2628 struct dquot *dquot; 2629 int err; 2630 2631 if (!sb->dq_op->get_next_id) 2632 return -ENOSYS; 2633 err = sb->dq_op->get_next_id(sb, qid); 2634 if (err < 0) 2635 return err; 2636 dquot = dqget(sb, *qid); 2637 if (IS_ERR(dquot)) 2638 return PTR_ERR(dquot); 2639 do_get_dqblk(dquot, di); 2640 dqput(dquot); 2641 2642 return 0; 2643 } 2644 EXPORT_SYMBOL(dquot_get_next_dqblk); 2645 2646 #define VFS_QC_MASK \ 2647 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2648 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2649 QC_SPC_TIMER | QC_INO_TIMER) 2650 2651 /* Generic routine for setting common part of quota structure */ 2652 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2653 { 2654 struct mem_dqblk *dm = &dquot->dq_dqb; 2655 int check_blim = 0, check_ilim = 0; 2656 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2657 2658 if (di->d_fieldmask & ~VFS_QC_MASK) 2659 return -EINVAL; 2660 2661 if (((di->d_fieldmask & QC_SPC_SOFT) && 2662 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2663 ((di->d_fieldmask & QC_SPC_HARD) && 2664 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2665 ((di->d_fieldmask & QC_INO_SOFT) && 2666 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2667 ((di->d_fieldmask & QC_INO_HARD) && 2668 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2669 return -ERANGE; 2670 2671 spin_lock(&dquot->dq_dqb_lock); 2672 if (di->d_fieldmask & QC_SPACE) { 2673 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2674 check_blim = 1; 2675 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2676 } 2677 2678 if (di->d_fieldmask & QC_SPC_SOFT) 2679 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2680 if (di->d_fieldmask & QC_SPC_HARD) 2681 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2682 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2683 check_blim = 1; 2684 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2685 } 2686 2687 if (di->d_fieldmask & QC_INO_COUNT) { 2688 dm->dqb_curinodes = di->d_ino_count; 2689 check_ilim = 1; 2690 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2691 } 2692 2693 if (di->d_fieldmask & QC_INO_SOFT) 2694 dm->dqb_isoftlimit = di->d_ino_softlimit; 2695 if (di->d_fieldmask & QC_INO_HARD) 2696 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2697 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2698 check_ilim = 1; 2699 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2700 } 2701 2702 if (di->d_fieldmask & QC_SPC_TIMER) { 2703 dm->dqb_btime = di->d_spc_timer; 2704 check_blim = 1; 2705 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2706 } 2707 2708 if (di->d_fieldmask & QC_INO_TIMER) { 2709 dm->dqb_itime = di->d_ino_timer; 2710 check_ilim = 1; 2711 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2712 } 2713 2714 if (check_blim) { 2715 if (!dm->dqb_bsoftlimit || 2716 dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) { 2717 dm->dqb_btime = 0; 2718 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2719 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2720 /* Set grace only if user hasn't provided his own... */ 2721 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2722 } 2723 if (check_ilim) { 2724 if (!dm->dqb_isoftlimit || 2725 dm->dqb_curinodes <= dm->dqb_isoftlimit) { 2726 dm->dqb_itime = 0; 2727 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2728 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2729 /* Set grace only if user hasn't provided his own... */ 2730 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2731 } 2732 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2733 dm->dqb_isoftlimit) 2734 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2735 else 2736 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2737 spin_unlock(&dquot->dq_dqb_lock); 2738 mark_dquot_dirty(dquot); 2739 2740 return 0; 2741 } 2742 2743 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2744 struct qc_dqblk *di) 2745 { 2746 struct dquot *dquot; 2747 int rc; 2748 2749 dquot = dqget(sb, qid); 2750 if (IS_ERR(dquot)) { 2751 rc = PTR_ERR(dquot); 2752 goto out; 2753 } 2754 rc = do_set_dqblk(dquot, di); 2755 dqput(dquot); 2756 out: 2757 return rc; 2758 } 2759 EXPORT_SYMBOL(dquot_set_dqblk); 2760 2761 /* Generic routine for getting common part of quota file information */ 2762 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2763 { 2764 struct mem_dqinfo *mi; 2765 struct qc_type_state *tstate; 2766 struct quota_info *dqopt = sb_dqopt(sb); 2767 int type; 2768 2769 memset(state, 0, sizeof(*state)); 2770 for (type = 0; type < MAXQUOTAS; type++) { 2771 if (!sb_has_quota_active(sb, type)) 2772 continue; 2773 tstate = state->s_state + type; 2774 mi = sb_dqopt(sb)->info + type; 2775 tstate->flags = QCI_ACCT_ENABLED; 2776 spin_lock(&dq_data_lock); 2777 if (mi->dqi_flags & DQF_SYS_FILE) 2778 tstate->flags |= QCI_SYSFILE; 2779 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2780 tstate->flags |= QCI_ROOT_SQUASH; 2781 if (sb_has_quota_limits_enabled(sb, type)) 2782 tstate->flags |= QCI_LIMITS_ENFORCED; 2783 tstate->spc_timelimit = mi->dqi_bgrace; 2784 tstate->ino_timelimit = mi->dqi_igrace; 2785 if (dqopt->files[type]) { 2786 tstate->ino = dqopt->files[type]->i_ino; 2787 tstate->blocks = dqopt->files[type]->i_blocks; 2788 } 2789 tstate->nextents = 1; /* We don't know... */ 2790 spin_unlock(&dq_data_lock); 2791 } 2792 return 0; 2793 } 2794 EXPORT_SYMBOL(dquot_get_state); 2795 2796 /* Generic routine for setting common part of quota file information */ 2797 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2798 { 2799 struct mem_dqinfo *mi; 2800 int err = 0; 2801 2802 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2803 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2804 return -EINVAL; 2805 if (!sb_has_quota_active(sb, type)) 2806 return -ESRCH; 2807 mi = sb_dqopt(sb)->info + type; 2808 if (ii->i_fieldmask & QC_FLAGS) { 2809 if ((ii->i_flags & QCI_ROOT_SQUASH && 2810 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2811 return -EINVAL; 2812 } 2813 spin_lock(&dq_data_lock); 2814 if (ii->i_fieldmask & QC_SPC_TIMER) 2815 mi->dqi_bgrace = ii->i_spc_timelimit; 2816 if (ii->i_fieldmask & QC_INO_TIMER) 2817 mi->dqi_igrace = ii->i_ino_timelimit; 2818 if (ii->i_fieldmask & QC_FLAGS) { 2819 if (ii->i_flags & QCI_ROOT_SQUASH) 2820 mi->dqi_flags |= DQF_ROOT_SQUASH; 2821 else 2822 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2823 } 2824 spin_unlock(&dq_data_lock); 2825 mark_info_dirty(sb, type); 2826 /* Force write to disk */ 2827 sb->dq_op->write_info(sb, type); 2828 return err; 2829 } 2830 EXPORT_SYMBOL(dquot_set_dqinfo); 2831 2832 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2833 .quota_enable = dquot_quota_enable, 2834 .quota_disable = dquot_quota_disable, 2835 .quota_sync = dquot_quota_sync, 2836 .get_state = dquot_get_state, 2837 .set_info = dquot_set_dqinfo, 2838 .get_dqblk = dquot_get_dqblk, 2839 .get_nextdqblk = dquot_get_next_dqblk, 2840 .set_dqblk = dquot_set_dqblk 2841 }; 2842 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2843 2844 static int do_proc_dqstats(struct ctl_table *table, int write, 2845 void *buffer, size_t *lenp, loff_t *ppos) 2846 { 2847 unsigned int type = (unsigned long *)table->data - dqstats.stat; 2848 s64 value = percpu_counter_sum(&dqstats.counter[type]); 2849 2850 /* Filter negative values for non-monotonic counters */ 2851 if (value < 0 && (type == DQST_ALLOC_DQUOTS || 2852 type == DQST_FREE_DQUOTS)) 2853 value = 0; 2854 2855 /* Update global table */ 2856 dqstats.stat[type] = value; 2857 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 2858 } 2859 2860 static struct ctl_table fs_dqstats_table[] = { 2861 { 2862 .procname = "lookups", 2863 .data = &dqstats.stat[DQST_LOOKUPS], 2864 .maxlen = sizeof(unsigned long), 2865 .mode = 0444, 2866 .proc_handler = do_proc_dqstats, 2867 }, 2868 { 2869 .procname = "drops", 2870 .data = &dqstats.stat[DQST_DROPS], 2871 .maxlen = sizeof(unsigned long), 2872 .mode = 0444, 2873 .proc_handler = do_proc_dqstats, 2874 }, 2875 { 2876 .procname = "reads", 2877 .data = &dqstats.stat[DQST_READS], 2878 .maxlen = sizeof(unsigned long), 2879 .mode = 0444, 2880 .proc_handler = do_proc_dqstats, 2881 }, 2882 { 2883 .procname = "writes", 2884 .data = &dqstats.stat[DQST_WRITES], 2885 .maxlen = sizeof(unsigned long), 2886 .mode = 0444, 2887 .proc_handler = do_proc_dqstats, 2888 }, 2889 { 2890 .procname = "cache_hits", 2891 .data = &dqstats.stat[DQST_CACHE_HITS], 2892 .maxlen = sizeof(unsigned long), 2893 .mode = 0444, 2894 .proc_handler = do_proc_dqstats, 2895 }, 2896 { 2897 .procname = "allocated_dquots", 2898 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2899 .maxlen = sizeof(unsigned long), 2900 .mode = 0444, 2901 .proc_handler = do_proc_dqstats, 2902 }, 2903 { 2904 .procname = "free_dquots", 2905 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2906 .maxlen = sizeof(unsigned long), 2907 .mode = 0444, 2908 .proc_handler = do_proc_dqstats, 2909 }, 2910 { 2911 .procname = "syncs", 2912 .data = &dqstats.stat[DQST_SYNCS], 2913 .maxlen = sizeof(unsigned long), 2914 .mode = 0444, 2915 .proc_handler = do_proc_dqstats, 2916 }, 2917 #ifdef CONFIG_PRINT_QUOTA_WARNING 2918 { 2919 .procname = "warnings", 2920 .data = &flag_print_warnings, 2921 .maxlen = sizeof(int), 2922 .mode = 0644, 2923 .proc_handler = proc_dointvec, 2924 }, 2925 #endif 2926 { }, 2927 }; 2928 2929 static struct ctl_table fs_table[] = { 2930 { 2931 .procname = "quota", 2932 .mode = 0555, 2933 .child = fs_dqstats_table, 2934 }, 2935 { }, 2936 }; 2937 2938 static struct ctl_table sys_table[] = { 2939 { 2940 .procname = "fs", 2941 .mode = 0555, 2942 .child = fs_table, 2943 }, 2944 { }, 2945 }; 2946 2947 static int __init dquot_init(void) 2948 { 2949 int i, ret; 2950 unsigned long nr_hash, order; 2951 2952 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2953 2954 register_sysctl_table(sys_table); 2955 2956 dquot_cachep = kmem_cache_create("dquot", 2957 sizeof(struct dquot), sizeof(unsigned long) * 4, 2958 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2959 SLAB_MEM_SPREAD|SLAB_PANIC), 2960 NULL); 2961 2962 order = 0; 2963 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2964 if (!dquot_hash) 2965 panic("Cannot create dquot hash table"); 2966 2967 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2968 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2969 if (ret) 2970 panic("Cannot create dquot stat counters"); 2971 } 2972 2973 /* Find power-of-two hlist_heads which can fit into allocation */ 2974 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2975 dq_hash_bits = ilog2(nr_hash); 2976 2977 nr_hash = 1UL << dq_hash_bits; 2978 dq_hash_mask = nr_hash - 1; 2979 for (i = 0; i < nr_hash; i++) 2980 INIT_HLIST_HEAD(dquot_hash + i); 2981 2982 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2983 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2984 2985 if (register_shrinker(&dqcache_shrinker)) 2986 panic("Cannot register dquot shrinker"); 2987 2988 return 0; 2989 } 2990 fs_initcall(dquot_init); 2991