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