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 (!ret && err) 649 ret = err; 650 dqput(dquot); 651 spin_lock(&dq_list_lock); 652 } 653 spin_unlock(&dq_list_lock); 654 } 655 656 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 657 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 658 && info_dirty(&dqopt->info[cnt])) 659 sb->dq_op->write_info(sb, cnt); 660 dqstats_inc(DQST_SYNCS); 661 662 return ret; 663 } 664 EXPORT_SYMBOL(dquot_writeback_dquots); 665 666 /* Write all dquot structures to disk and make them visible from userspace */ 667 int dquot_quota_sync(struct super_block *sb, int type) 668 { 669 struct quota_info *dqopt = sb_dqopt(sb); 670 int cnt; 671 int ret; 672 673 ret = dquot_writeback_dquots(sb, type); 674 if (ret) 675 return ret; 676 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 677 return 0; 678 679 /* This is not very clever (and fast) but currently I don't know about 680 * any other simple way of getting quota data to disk and we must get 681 * them there for userspace to be visible... */ 682 if (sb->s_op->sync_fs) 683 sb->s_op->sync_fs(sb, 1); 684 sync_blockdev(sb->s_bdev); 685 686 /* 687 * Now when everything is written we can discard the pagecache so 688 * that userspace sees the changes. 689 */ 690 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 691 if (type != -1 && cnt != type) 692 continue; 693 if (!sb_has_quota_active(sb, cnt)) 694 continue; 695 inode_lock(dqopt->files[cnt]); 696 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 697 inode_unlock(dqopt->files[cnt]); 698 } 699 700 return 0; 701 } 702 EXPORT_SYMBOL(dquot_quota_sync); 703 704 static unsigned long 705 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 706 { 707 struct list_head *head; 708 struct dquot *dquot; 709 unsigned long freed = 0; 710 711 spin_lock(&dq_list_lock); 712 head = free_dquots.prev; 713 while (head != &free_dquots && sc->nr_to_scan) { 714 dquot = list_entry(head, struct dquot, dq_free); 715 remove_dquot_hash(dquot); 716 remove_free_dquot(dquot); 717 remove_inuse(dquot); 718 do_destroy_dquot(dquot); 719 sc->nr_to_scan--; 720 freed++; 721 head = free_dquots.prev; 722 } 723 spin_unlock(&dq_list_lock); 724 return freed; 725 } 726 727 static unsigned long 728 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 729 { 730 return vfs_pressure_ratio( 731 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 732 } 733 734 static struct shrinker dqcache_shrinker = { 735 .count_objects = dqcache_shrink_count, 736 .scan_objects = dqcache_shrink_scan, 737 .seeks = DEFAULT_SEEKS, 738 }; 739 740 /* 741 * Put reference to dquot 742 */ 743 void dqput(struct dquot *dquot) 744 { 745 int ret; 746 747 if (!dquot) 748 return; 749 #ifdef CONFIG_QUOTA_DEBUG 750 if (!atomic_read(&dquot->dq_count)) { 751 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 752 quotatypes[dquot->dq_id.type], 753 from_kqid(&init_user_ns, dquot->dq_id)); 754 BUG(); 755 } 756 #endif 757 dqstats_inc(DQST_DROPS); 758 we_slept: 759 spin_lock(&dq_list_lock); 760 if (atomic_read(&dquot->dq_count) > 1) { 761 /* We have more than one user... nothing to do */ 762 atomic_dec(&dquot->dq_count); 763 /* Releasing dquot during quotaoff phase? */ 764 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 765 atomic_read(&dquot->dq_count) == 1) 766 wake_up(&dquot_ref_wq); 767 spin_unlock(&dq_list_lock); 768 return; 769 } 770 /* Need to release dquot? */ 771 if (dquot_dirty(dquot)) { 772 spin_unlock(&dq_list_lock); 773 /* Commit dquot before releasing */ 774 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 775 if (ret < 0) { 776 quota_error(dquot->dq_sb, "Can't write quota structure" 777 " (error %d). Quota may get out of sync!", 778 ret); 779 /* 780 * We clear dirty bit anyway, so that we avoid 781 * infinite loop here 782 */ 783 clear_dquot_dirty(dquot); 784 } 785 goto we_slept; 786 } 787 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 788 spin_unlock(&dq_list_lock); 789 dquot->dq_sb->dq_op->release_dquot(dquot); 790 goto we_slept; 791 } 792 atomic_dec(&dquot->dq_count); 793 #ifdef CONFIG_QUOTA_DEBUG 794 /* sanity check */ 795 BUG_ON(!list_empty(&dquot->dq_free)); 796 #endif 797 put_dquot_last(dquot); 798 spin_unlock(&dq_list_lock); 799 } 800 EXPORT_SYMBOL(dqput); 801 802 struct dquot *dquot_alloc(struct super_block *sb, int type) 803 { 804 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 805 } 806 EXPORT_SYMBOL(dquot_alloc); 807 808 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 809 { 810 struct dquot *dquot; 811 812 dquot = sb->dq_op->alloc_dquot(sb, type); 813 if(!dquot) 814 return NULL; 815 816 mutex_init(&dquot->dq_lock); 817 INIT_LIST_HEAD(&dquot->dq_free); 818 INIT_LIST_HEAD(&dquot->dq_inuse); 819 INIT_HLIST_NODE(&dquot->dq_hash); 820 INIT_LIST_HEAD(&dquot->dq_dirty); 821 dquot->dq_sb = sb; 822 dquot->dq_id = make_kqid_invalid(type); 823 atomic_set(&dquot->dq_count, 1); 824 spin_lock_init(&dquot->dq_dqb_lock); 825 826 return dquot; 827 } 828 829 /* 830 * Get reference to dquot 831 * 832 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 833 * destroying our dquot by: 834 * a) checking for quota flags under dq_list_lock and 835 * b) getting a reference to dquot before we release dq_list_lock 836 */ 837 struct dquot *dqget(struct super_block *sb, struct kqid qid) 838 { 839 unsigned int hashent = hashfn(sb, qid); 840 struct dquot *dquot, *empty = NULL; 841 842 if (!qid_has_mapping(sb->s_user_ns, qid)) 843 return ERR_PTR(-EINVAL); 844 845 if (!sb_has_quota_active(sb, qid.type)) 846 return ERR_PTR(-ESRCH); 847 we_slept: 848 spin_lock(&dq_list_lock); 849 spin_lock(&dq_state_lock); 850 if (!sb_has_quota_active(sb, qid.type)) { 851 spin_unlock(&dq_state_lock); 852 spin_unlock(&dq_list_lock); 853 dquot = ERR_PTR(-ESRCH); 854 goto out; 855 } 856 spin_unlock(&dq_state_lock); 857 858 dquot = find_dquot(hashent, sb, qid); 859 if (!dquot) { 860 if (!empty) { 861 spin_unlock(&dq_list_lock); 862 empty = get_empty_dquot(sb, qid.type); 863 if (!empty) 864 schedule(); /* Try to wait for a moment... */ 865 goto we_slept; 866 } 867 dquot = empty; 868 empty = NULL; 869 dquot->dq_id = qid; 870 /* all dquots go on the inuse_list */ 871 put_inuse(dquot); 872 /* hash it first so it can be found */ 873 insert_dquot_hash(dquot); 874 spin_unlock(&dq_list_lock); 875 dqstats_inc(DQST_LOOKUPS); 876 } else { 877 if (!atomic_read(&dquot->dq_count)) 878 remove_free_dquot(dquot); 879 atomic_inc(&dquot->dq_count); 880 spin_unlock(&dq_list_lock); 881 dqstats_inc(DQST_CACHE_HITS); 882 dqstats_inc(DQST_LOOKUPS); 883 } 884 /* Wait for dq_lock - after this we know that either dquot_release() is 885 * already finished or it will be canceled due to dq_count > 1 test */ 886 wait_on_dquot(dquot); 887 /* Read the dquot / allocate space in quota file */ 888 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 889 int err; 890 891 err = sb->dq_op->acquire_dquot(dquot); 892 if (err < 0) { 893 dqput(dquot); 894 dquot = ERR_PTR(err); 895 goto out; 896 } 897 } 898 /* 899 * Make sure following reads see filled structure - paired with 900 * smp_mb__before_atomic() in dquot_acquire(). 901 */ 902 smp_rmb(); 903 #ifdef CONFIG_QUOTA_DEBUG 904 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 905 #endif 906 out: 907 if (empty) 908 do_destroy_dquot(empty); 909 910 return dquot; 911 } 912 EXPORT_SYMBOL(dqget); 913 914 static inline struct dquot **i_dquot(struct inode *inode) 915 { 916 return inode->i_sb->s_op->get_dquots(inode); 917 } 918 919 static int dqinit_needed(struct inode *inode, int type) 920 { 921 struct dquot * const *dquots; 922 int cnt; 923 924 if (IS_NOQUOTA(inode)) 925 return 0; 926 927 dquots = i_dquot(inode); 928 if (type != -1) 929 return !dquots[type]; 930 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 931 if (!dquots[cnt]) 932 return 1; 933 return 0; 934 } 935 936 /* This routine is guarded by s_umount semaphore */ 937 static void add_dquot_ref(struct super_block *sb, int type) 938 { 939 struct inode *inode, *old_inode = NULL; 940 #ifdef CONFIG_QUOTA_DEBUG 941 int reserved = 0; 942 #endif 943 944 spin_lock(&sb->s_inode_list_lock); 945 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 946 spin_lock(&inode->i_lock); 947 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 948 !atomic_read(&inode->i_writecount) || 949 !dqinit_needed(inode, type)) { 950 spin_unlock(&inode->i_lock); 951 continue; 952 } 953 __iget(inode); 954 spin_unlock(&inode->i_lock); 955 spin_unlock(&sb->s_inode_list_lock); 956 957 #ifdef CONFIG_QUOTA_DEBUG 958 if (unlikely(inode_get_rsv_space(inode) > 0)) 959 reserved = 1; 960 #endif 961 iput(old_inode); 962 __dquot_initialize(inode, type); 963 964 /* 965 * We hold a reference to 'inode' so it couldn't have been 966 * removed from s_inodes list while we dropped the 967 * s_inode_list_lock. We cannot iput the inode now as we can be 968 * holding the last reference and we cannot iput it under 969 * s_inode_list_lock. So we keep the reference and iput it 970 * later. 971 */ 972 old_inode = inode; 973 spin_lock(&sb->s_inode_list_lock); 974 } 975 spin_unlock(&sb->s_inode_list_lock); 976 iput(old_inode); 977 978 #ifdef CONFIG_QUOTA_DEBUG 979 if (reserved) { 980 quota_error(sb, "Writes happened before quota was turned on " 981 "thus quota information is probably inconsistent. " 982 "Please run quotacheck(8)"); 983 } 984 #endif 985 } 986 987 /* 988 * Remove references to dquots from inode and add dquot to list for freeing 989 * if we have the last reference to dquot 990 */ 991 static void remove_inode_dquot_ref(struct inode *inode, int type, 992 struct list_head *tofree_head) 993 { 994 struct dquot **dquots = i_dquot(inode); 995 struct dquot *dquot = dquots[type]; 996 997 if (!dquot) 998 return; 999 1000 dquots[type] = NULL; 1001 if (list_empty(&dquot->dq_free)) { 1002 /* 1003 * The inode still has reference to dquot so it can't be in the 1004 * free list 1005 */ 1006 spin_lock(&dq_list_lock); 1007 list_add(&dquot->dq_free, tofree_head); 1008 spin_unlock(&dq_list_lock); 1009 } else { 1010 /* 1011 * Dquot is already in a list to put so we won't drop the last 1012 * reference here. 1013 */ 1014 dqput(dquot); 1015 } 1016 } 1017 1018 /* 1019 * Free list of dquots 1020 * Dquots are removed from inodes and no new references can be got so we are 1021 * the only ones holding reference 1022 */ 1023 static void put_dquot_list(struct list_head *tofree_head) 1024 { 1025 struct list_head *act_head; 1026 struct dquot *dquot; 1027 1028 act_head = tofree_head->next; 1029 while (act_head != tofree_head) { 1030 dquot = list_entry(act_head, struct dquot, dq_free); 1031 act_head = act_head->next; 1032 /* Remove dquot from the list so we won't have problems... */ 1033 list_del_init(&dquot->dq_free); 1034 dqput(dquot); 1035 } 1036 } 1037 1038 static void remove_dquot_ref(struct super_block *sb, int type, 1039 struct list_head *tofree_head) 1040 { 1041 struct inode *inode; 1042 int reserved = 0; 1043 1044 spin_lock(&sb->s_inode_list_lock); 1045 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1046 /* 1047 * We have to scan also I_NEW inodes because they can already 1048 * have quota pointer initialized. Luckily, we need to touch 1049 * only quota pointers and these have separate locking 1050 * (dq_data_lock). 1051 */ 1052 spin_lock(&dq_data_lock); 1053 if (!IS_NOQUOTA(inode)) { 1054 if (unlikely(inode_get_rsv_space(inode) > 0)) 1055 reserved = 1; 1056 remove_inode_dquot_ref(inode, type, tofree_head); 1057 } 1058 spin_unlock(&dq_data_lock); 1059 } 1060 spin_unlock(&sb->s_inode_list_lock); 1061 #ifdef CONFIG_QUOTA_DEBUG 1062 if (reserved) { 1063 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1064 " was disabled thus quota information is probably " 1065 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1066 } 1067 #endif 1068 } 1069 1070 /* Gather all references from inodes and drop them */ 1071 static void drop_dquot_ref(struct super_block *sb, int type) 1072 { 1073 LIST_HEAD(tofree_head); 1074 1075 if (sb->dq_op) { 1076 remove_dquot_ref(sb, type, &tofree_head); 1077 synchronize_srcu(&dquot_srcu); 1078 put_dquot_list(&tofree_head); 1079 } 1080 } 1081 1082 static inline 1083 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1084 { 1085 if (dquot->dq_dqb.dqb_rsvspace >= number) 1086 dquot->dq_dqb.dqb_rsvspace -= number; 1087 else { 1088 WARN_ON_ONCE(1); 1089 dquot->dq_dqb.dqb_rsvspace = 0; 1090 } 1091 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1092 dquot->dq_dqb.dqb_bsoftlimit) 1093 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1094 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1095 } 1096 1097 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1098 { 1099 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1100 dquot->dq_dqb.dqb_curinodes >= number) 1101 dquot->dq_dqb.dqb_curinodes -= number; 1102 else 1103 dquot->dq_dqb.dqb_curinodes = 0; 1104 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1105 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1106 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1107 } 1108 1109 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1110 { 1111 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1112 dquot->dq_dqb.dqb_curspace >= number) 1113 dquot->dq_dqb.dqb_curspace -= number; 1114 else 1115 dquot->dq_dqb.dqb_curspace = 0; 1116 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1117 dquot->dq_dqb.dqb_bsoftlimit) 1118 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1119 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1120 } 1121 1122 struct dquot_warn { 1123 struct super_block *w_sb; 1124 struct kqid w_dq_id; 1125 short w_type; 1126 }; 1127 1128 static int warning_issued(struct dquot *dquot, const int warntype) 1129 { 1130 int flag = (warntype == QUOTA_NL_BHARDWARN || 1131 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1132 ((warntype == QUOTA_NL_IHARDWARN || 1133 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1134 1135 if (!flag) 1136 return 0; 1137 return test_and_set_bit(flag, &dquot->dq_flags); 1138 } 1139 1140 #ifdef CONFIG_PRINT_QUOTA_WARNING 1141 static int flag_print_warnings = 1; 1142 1143 static int need_print_warning(struct dquot_warn *warn) 1144 { 1145 if (!flag_print_warnings) 1146 return 0; 1147 1148 switch (warn->w_dq_id.type) { 1149 case USRQUOTA: 1150 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1151 case GRPQUOTA: 1152 return in_group_p(warn->w_dq_id.gid); 1153 case PRJQUOTA: 1154 return 1; 1155 } 1156 return 0; 1157 } 1158 1159 /* Print warning to user which exceeded quota */ 1160 static void print_warning(struct dquot_warn *warn) 1161 { 1162 char *msg = NULL; 1163 struct tty_struct *tty; 1164 int warntype = warn->w_type; 1165 1166 if (warntype == QUOTA_NL_IHARDBELOW || 1167 warntype == QUOTA_NL_ISOFTBELOW || 1168 warntype == QUOTA_NL_BHARDBELOW || 1169 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1170 return; 1171 1172 tty = get_current_tty(); 1173 if (!tty) 1174 return; 1175 tty_write_message(tty, warn->w_sb->s_id); 1176 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1177 tty_write_message(tty, ": warning, "); 1178 else 1179 tty_write_message(tty, ": write failed, "); 1180 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1181 switch (warntype) { 1182 case QUOTA_NL_IHARDWARN: 1183 msg = " file limit reached.\r\n"; 1184 break; 1185 case QUOTA_NL_ISOFTLONGWARN: 1186 msg = " file quota exceeded too long.\r\n"; 1187 break; 1188 case QUOTA_NL_ISOFTWARN: 1189 msg = " file quota exceeded.\r\n"; 1190 break; 1191 case QUOTA_NL_BHARDWARN: 1192 msg = " block limit reached.\r\n"; 1193 break; 1194 case QUOTA_NL_BSOFTLONGWARN: 1195 msg = " block quota exceeded too long.\r\n"; 1196 break; 1197 case QUOTA_NL_BSOFTWARN: 1198 msg = " block quota exceeded.\r\n"; 1199 break; 1200 } 1201 tty_write_message(tty, msg); 1202 tty_kref_put(tty); 1203 } 1204 #endif 1205 1206 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1207 int warntype) 1208 { 1209 if (warning_issued(dquot, warntype)) 1210 return; 1211 warn->w_type = warntype; 1212 warn->w_sb = dquot->dq_sb; 1213 warn->w_dq_id = dquot->dq_id; 1214 } 1215 1216 /* 1217 * Write warnings to the console and send warning messages over netlink. 1218 * 1219 * Note that this function can call into tty and networking code. 1220 */ 1221 static void flush_warnings(struct dquot_warn *warn) 1222 { 1223 int i; 1224 1225 for (i = 0; i < MAXQUOTAS; i++) { 1226 if (warn[i].w_type == QUOTA_NL_NOWARN) 1227 continue; 1228 #ifdef CONFIG_PRINT_QUOTA_WARNING 1229 print_warning(&warn[i]); 1230 #endif 1231 quota_send_warning(warn[i].w_dq_id, 1232 warn[i].w_sb->s_dev, warn[i].w_type); 1233 } 1234 } 1235 1236 static int ignore_hardlimit(struct dquot *dquot) 1237 { 1238 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1239 1240 return capable(CAP_SYS_RESOURCE) && 1241 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1242 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1243 } 1244 1245 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1246 struct dquot_warn *warn) 1247 { 1248 qsize_t newinodes; 1249 int ret = 0; 1250 1251 spin_lock(&dquot->dq_dqb_lock); 1252 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1253 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1254 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1255 goto add; 1256 1257 if (dquot->dq_dqb.dqb_ihardlimit && 1258 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1259 !ignore_hardlimit(dquot)) { 1260 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1261 ret = -EDQUOT; 1262 goto out; 1263 } 1264 1265 if (dquot->dq_dqb.dqb_isoftlimit && 1266 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1267 dquot->dq_dqb.dqb_itime && 1268 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1269 !ignore_hardlimit(dquot)) { 1270 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1271 ret = -EDQUOT; 1272 goto out; 1273 } 1274 1275 if (dquot->dq_dqb.dqb_isoftlimit && 1276 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1277 dquot->dq_dqb.dqb_itime == 0) { 1278 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1279 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1280 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1281 } 1282 add: 1283 dquot->dq_dqb.dqb_curinodes = newinodes; 1284 1285 out: 1286 spin_unlock(&dquot->dq_dqb_lock); 1287 return ret; 1288 } 1289 1290 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1291 qsize_t rsv_space, unsigned int flags, 1292 struct dquot_warn *warn) 1293 { 1294 qsize_t tspace; 1295 struct super_block *sb = dquot->dq_sb; 1296 int ret = 0; 1297 1298 spin_lock(&dquot->dq_dqb_lock); 1299 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1300 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1301 goto finish; 1302 1303 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1304 + space + rsv_space; 1305 1306 if (dquot->dq_dqb.dqb_bhardlimit && 1307 tspace > dquot->dq_dqb.dqb_bhardlimit && 1308 !ignore_hardlimit(dquot)) { 1309 if (flags & DQUOT_SPACE_WARN) 1310 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1311 ret = -EDQUOT; 1312 goto finish; 1313 } 1314 1315 if (dquot->dq_dqb.dqb_bsoftlimit && 1316 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1317 dquot->dq_dqb.dqb_btime && 1318 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1319 !ignore_hardlimit(dquot)) { 1320 if (flags & DQUOT_SPACE_WARN) 1321 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1322 ret = -EDQUOT; 1323 goto finish; 1324 } 1325 1326 if (dquot->dq_dqb.dqb_bsoftlimit && 1327 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1328 dquot->dq_dqb.dqb_btime == 0) { 1329 if (flags & DQUOT_SPACE_WARN) { 1330 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1331 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1332 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1333 } else { 1334 /* 1335 * We don't allow preallocation to exceed softlimit so exceeding will 1336 * be always printed 1337 */ 1338 ret = -EDQUOT; 1339 goto finish; 1340 } 1341 } 1342 finish: 1343 /* 1344 * We have to be careful and go through warning generation & grace time 1345 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1346 * only here... 1347 */ 1348 if (flags & DQUOT_SPACE_NOFAIL) 1349 ret = 0; 1350 if (!ret) { 1351 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1352 dquot->dq_dqb.dqb_curspace += space; 1353 } 1354 spin_unlock(&dquot->dq_dqb_lock); 1355 return ret; 1356 } 1357 1358 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1359 { 1360 qsize_t newinodes; 1361 1362 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1363 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1364 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1365 return QUOTA_NL_NOWARN; 1366 1367 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1368 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1369 return QUOTA_NL_ISOFTBELOW; 1370 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1371 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1372 return QUOTA_NL_IHARDBELOW; 1373 return QUOTA_NL_NOWARN; 1374 } 1375 1376 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1377 { 1378 qsize_t tspace; 1379 1380 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1381 1382 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1383 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1384 return QUOTA_NL_NOWARN; 1385 1386 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1387 return QUOTA_NL_BSOFTBELOW; 1388 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1389 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1390 return QUOTA_NL_BHARDBELOW; 1391 return QUOTA_NL_NOWARN; 1392 } 1393 1394 static int dquot_active(const struct inode *inode) 1395 { 1396 struct super_block *sb = inode->i_sb; 1397 1398 if (IS_NOQUOTA(inode)) 1399 return 0; 1400 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1401 } 1402 1403 /* 1404 * Initialize quota pointers in inode 1405 * 1406 * It is better to call this function outside of any transaction as it 1407 * might need a lot of space in journal for dquot structure allocation. 1408 */ 1409 static int __dquot_initialize(struct inode *inode, int type) 1410 { 1411 int cnt, init_needed = 0; 1412 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1413 struct super_block *sb = inode->i_sb; 1414 qsize_t rsv; 1415 int ret = 0; 1416 1417 if (!dquot_active(inode)) 1418 return 0; 1419 1420 dquots = i_dquot(inode); 1421 1422 /* First get references to structures we might need. */ 1423 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1424 struct kqid qid; 1425 kprojid_t projid; 1426 int rc; 1427 struct dquot *dquot; 1428 1429 if (type != -1 && cnt != type) 1430 continue; 1431 /* 1432 * The i_dquot should have been initialized in most cases, 1433 * we check it without locking here to avoid unnecessary 1434 * dqget()/dqput() calls. 1435 */ 1436 if (dquots[cnt]) 1437 continue; 1438 1439 if (!sb_has_quota_active(sb, cnt)) 1440 continue; 1441 1442 init_needed = 1; 1443 1444 switch (cnt) { 1445 case USRQUOTA: 1446 qid = make_kqid_uid(inode->i_uid); 1447 break; 1448 case GRPQUOTA: 1449 qid = make_kqid_gid(inode->i_gid); 1450 break; 1451 case PRJQUOTA: 1452 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1453 if (rc) 1454 continue; 1455 qid = make_kqid_projid(projid); 1456 break; 1457 } 1458 dquot = dqget(sb, qid); 1459 if (IS_ERR(dquot)) { 1460 /* We raced with somebody turning quotas off... */ 1461 if (PTR_ERR(dquot) != -ESRCH) { 1462 ret = PTR_ERR(dquot); 1463 goto out_put; 1464 } 1465 dquot = NULL; 1466 } 1467 got[cnt] = dquot; 1468 } 1469 1470 /* All required i_dquot has been initialized */ 1471 if (!init_needed) 1472 return 0; 1473 1474 spin_lock(&dq_data_lock); 1475 if (IS_NOQUOTA(inode)) 1476 goto out_lock; 1477 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1478 if (type != -1 && cnt != type) 1479 continue; 1480 /* Avoid races with quotaoff() */ 1481 if (!sb_has_quota_active(sb, cnt)) 1482 continue; 1483 /* We could race with quotaon or dqget() could have failed */ 1484 if (!got[cnt]) 1485 continue; 1486 if (!dquots[cnt]) { 1487 dquots[cnt] = got[cnt]; 1488 got[cnt] = NULL; 1489 /* 1490 * Make quota reservation system happy if someone 1491 * did a write before quota was turned on 1492 */ 1493 rsv = inode_get_rsv_space(inode); 1494 if (unlikely(rsv)) { 1495 spin_lock(&inode->i_lock); 1496 /* Get reservation again under proper lock */ 1497 rsv = __inode_get_rsv_space(inode); 1498 spin_lock(&dquots[cnt]->dq_dqb_lock); 1499 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1500 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1501 spin_unlock(&inode->i_lock); 1502 } 1503 } 1504 } 1505 out_lock: 1506 spin_unlock(&dq_data_lock); 1507 out_put: 1508 /* Drop unused references */ 1509 dqput_all(got); 1510 1511 return ret; 1512 } 1513 1514 int dquot_initialize(struct inode *inode) 1515 { 1516 return __dquot_initialize(inode, -1); 1517 } 1518 EXPORT_SYMBOL(dquot_initialize); 1519 1520 bool dquot_initialize_needed(struct inode *inode) 1521 { 1522 struct dquot **dquots; 1523 int i; 1524 1525 if (!dquot_active(inode)) 1526 return false; 1527 1528 dquots = i_dquot(inode); 1529 for (i = 0; i < MAXQUOTAS; i++) 1530 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1531 return true; 1532 return false; 1533 } 1534 EXPORT_SYMBOL(dquot_initialize_needed); 1535 1536 /* 1537 * Release all quotas referenced by inode. 1538 * 1539 * This function only be called on inode free or converting 1540 * a file to quota file, no other users for the i_dquot in 1541 * both cases, so we needn't call synchronize_srcu() after 1542 * clearing i_dquot. 1543 */ 1544 static void __dquot_drop(struct inode *inode) 1545 { 1546 int cnt; 1547 struct dquot **dquots = i_dquot(inode); 1548 struct dquot *put[MAXQUOTAS]; 1549 1550 spin_lock(&dq_data_lock); 1551 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1552 put[cnt] = dquots[cnt]; 1553 dquots[cnt] = NULL; 1554 } 1555 spin_unlock(&dq_data_lock); 1556 dqput_all(put); 1557 } 1558 1559 void dquot_drop(struct inode *inode) 1560 { 1561 struct dquot * const *dquots; 1562 int cnt; 1563 1564 if (IS_NOQUOTA(inode)) 1565 return; 1566 1567 /* 1568 * Test before calling to rule out calls from proc and such 1569 * where we are not allowed to block. Note that this is 1570 * actually reliable test even without the lock - the caller 1571 * must assure that nobody can come after the DQUOT_DROP and 1572 * add quota pointers back anyway. 1573 */ 1574 dquots = i_dquot(inode); 1575 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1576 if (dquots[cnt]) 1577 break; 1578 } 1579 1580 if (cnt < MAXQUOTAS) 1581 __dquot_drop(inode); 1582 } 1583 EXPORT_SYMBOL(dquot_drop); 1584 1585 /* 1586 * inode_reserved_space is managed internally by quota, and protected by 1587 * i_lock similar to i_blocks+i_bytes. 1588 */ 1589 static qsize_t *inode_reserved_space(struct inode * inode) 1590 { 1591 /* Filesystem must explicitly define it's own method in order to use 1592 * quota reservation interface */ 1593 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1594 return inode->i_sb->dq_op->get_reserved_space(inode); 1595 } 1596 1597 static qsize_t __inode_get_rsv_space(struct inode *inode) 1598 { 1599 if (!inode->i_sb->dq_op->get_reserved_space) 1600 return 0; 1601 return *inode_reserved_space(inode); 1602 } 1603 1604 static qsize_t inode_get_rsv_space(struct inode *inode) 1605 { 1606 qsize_t ret; 1607 1608 if (!inode->i_sb->dq_op->get_reserved_space) 1609 return 0; 1610 spin_lock(&inode->i_lock); 1611 ret = __inode_get_rsv_space(inode); 1612 spin_unlock(&inode->i_lock); 1613 return ret; 1614 } 1615 1616 /* 1617 * This functions updates i_blocks+i_bytes fields and quota information 1618 * (together with appropriate checks). 1619 * 1620 * NOTE: We absolutely rely on the fact that caller dirties the inode 1621 * (usually helpers in quotaops.h care about this) and holds a handle for 1622 * the current transaction so that dquot write and inode write go into the 1623 * same transaction. 1624 */ 1625 1626 /* 1627 * This operation can block, but only after everything is updated 1628 */ 1629 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1630 { 1631 int cnt, ret = 0, index; 1632 struct dquot_warn warn[MAXQUOTAS]; 1633 int reserve = flags & DQUOT_SPACE_RESERVE; 1634 struct dquot **dquots; 1635 1636 if (!dquot_active(inode)) { 1637 if (reserve) { 1638 spin_lock(&inode->i_lock); 1639 *inode_reserved_space(inode) += number; 1640 spin_unlock(&inode->i_lock); 1641 } else { 1642 inode_add_bytes(inode, number); 1643 } 1644 goto out; 1645 } 1646 1647 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1648 warn[cnt].w_type = QUOTA_NL_NOWARN; 1649 1650 dquots = i_dquot(inode); 1651 index = srcu_read_lock(&dquot_srcu); 1652 spin_lock(&inode->i_lock); 1653 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1654 if (!dquots[cnt]) 1655 continue; 1656 if (flags & DQUOT_SPACE_RESERVE) { 1657 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1658 &warn[cnt]); 1659 } else { 1660 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1661 &warn[cnt]); 1662 } 1663 if (ret) { 1664 /* Back out changes we already did */ 1665 for (cnt--; cnt >= 0; cnt--) { 1666 if (!dquots[cnt]) 1667 continue; 1668 spin_lock(&dquots[cnt]->dq_dqb_lock); 1669 if (flags & DQUOT_SPACE_RESERVE) { 1670 dquots[cnt]->dq_dqb.dqb_rsvspace -= 1671 number; 1672 } else { 1673 dquots[cnt]->dq_dqb.dqb_curspace -= 1674 number; 1675 } 1676 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1677 } 1678 spin_unlock(&inode->i_lock); 1679 goto out_flush_warn; 1680 } 1681 } 1682 if (reserve) 1683 *inode_reserved_space(inode) += number; 1684 else 1685 __inode_add_bytes(inode, number); 1686 spin_unlock(&inode->i_lock); 1687 1688 if (reserve) 1689 goto out_flush_warn; 1690 mark_all_dquot_dirty(dquots); 1691 out_flush_warn: 1692 srcu_read_unlock(&dquot_srcu, index); 1693 flush_warnings(warn); 1694 out: 1695 return ret; 1696 } 1697 EXPORT_SYMBOL(__dquot_alloc_space); 1698 1699 /* 1700 * This operation can block, but only after everything is updated 1701 */ 1702 int dquot_alloc_inode(struct inode *inode) 1703 { 1704 int cnt, ret = 0, index; 1705 struct dquot_warn warn[MAXQUOTAS]; 1706 struct dquot * const *dquots; 1707 1708 if (!dquot_active(inode)) 1709 return 0; 1710 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1711 warn[cnt].w_type = QUOTA_NL_NOWARN; 1712 1713 dquots = i_dquot(inode); 1714 index = srcu_read_lock(&dquot_srcu); 1715 spin_lock(&inode->i_lock); 1716 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1717 if (!dquots[cnt]) 1718 continue; 1719 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1720 if (ret) { 1721 for (cnt--; cnt >= 0; cnt--) { 1722 if (!dquots[cnt]) 1723 continue; 1724 /* Back out changes we already did */ 1725 spin_lock(&dquots[cnt]->dq_dqb_lock); 1726 dquots[cnt]->dq_dqb.dqb_curinodes--; 1727 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1728 } 1729 goto warn_put_all; 1730 } 1731 } 1732 1733 warn_put_all: 1734 spin_unlock(&inode->i_lock); 1735 if (ret == 0) 1736 mark_all_dquot_dirty(dquots); 1737 srcu_read_unlock(&dquot_srcu, index); 1738 flush_warnings(warn); 1739 return ret; 1740 } 1741 EXPORT_SYMBOL(dquot_alloc_inode); 1742 1743 /* 1744 * Convert in-memory reserved quotas to real consumed quotas 1745 */ 1746 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1747 { 1748 struct dquot **dquots; 1749 int cnt, index; 1750 1751 if (!dquot_active(inode)) { 1752 spin_lock(&inode->i_lock); 1753 *inode_reserved_space(inode) -= number; 1754 __inode_add_bytes(inode, number); 1755 spin_unlock(&inode->i_lock); 1756 return 0; 1757 } 1758 1759 dquots = i_dquot(inode); 1760 index = srcu_read_lock(&dquot_srcu); 1761 spin_lock(&inode->i_lock); 1762 /* Claim reserved quotas to allocated quotas */ 1763 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1764 if (dquots[cnt]) { 1765 struct dquot *dquot = dquots[cnt]; 1766 1767 spin_lock(&dquot->dq_dqb_lock); 1768 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1769 number = dquot->dq_dqb.dqb_rsvspace; 1770 dquot->dq_dqb.dqb_curspace += number; 1771 dquot->dq_dqb.dqb_rsvspace -= number; 1772 spin_unlock(&dquot->dq_dqb_lock); 1773 } 1774 } 1775 /* Update inode bytes */ 1776 *inode_reserved_space(inode) -= number; 1777 __inode_add_bytes(inode, number); 1778 spin_unlock(&inode->i_lock); 1779 mark_all_dquot_dirty(dquots); 1780 srcu_read_unlock(&dquot_srcu, index); 1781 return 0; 1782 } 1783 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1784 1785 /* 1786 * Convert allocated space back to in-memory reserved quotas 1787 */ 1788 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1789 { 1790 struct dquot **dquots; 1791 int cnt, index; 1792 1793 if (!dquot_active(inode)) { 1794 spin_lock(&inode->i_lock); 1795 *inode_reserved_space(inode) += number; 1796 __inode_sub_bytes(inode, number); 1797 spin_unlock(&inode->i_lock); 1798 return; 1799 } 1800 1801 dquots = i_dquot(inode); 1802 index = srcu_read_lock(&dquot_srcu); 1803 spin_lock(&inode->i_lock); 1804 /* Claim reserved quotas to allocated quotas */ 1805 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1806 if (dquots[cnt]) { 1807 struct dquot *dquot = dquots[cnt]; 1808 1809 spin_lock(&dquot->dq_dqb_lock); 1810 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1811 number = dquot->dq_dqb.dqb_curspace; 1812 dquot->dq_dqb.dqb_rsvspace += number; 1813 dquot->dq_dqb.dqb_curspace -= number; 1814 spin_unlock(&dquot->dq_dqb_lock); 1815 } 1816 } 1817 /* Update inode bytes */ 1818 *inode_reserved_space(inode) += number; 1819 __inode_sub_bytes(inode, number); 1820 spin_unlock(&inode->i_lock); 1821 mark_all_dquot_dirty(dquots); 1822 srcu_read_unlock(&dquot_srcu, index); 1823 return; 1824 } 1825 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1826 1827 /* 1828 * This operation can block, but only after everything is updated 1829 */ 1830 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1831 { 1832 unsigned int cnt; 1833 struct dquot_warn warn[MAXQUOTAS]; 1834 struct dquot **dquots; 1835 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1836 1837 if (!dquot_active(inode)) { 1838 if (reserve) { 1839 spin_lock(&inode->i_lock); 1840 *inode_reserved_space(inode) -= number; 1841 spin_unlock(&inode->i_lock); 1842 } else { 1843 inode_sub_bytes(inode, number); 1844 } 1845 return; 1846 } 1847 1848 dquots = i_dquot(inode); 1849 index = srcu_read_lock(&dquot_srcu); 1850 spin_lock(&inode->i_lock); 1851 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1852 int wtype; 1853 1854 warn[cnt].w_type = QUOTA_NL_NOWARN; 1855 if (!dquots[cnt]) 1856 continue; 1857 spin_lock(&dquots[cnt]->dq_dqb_lock); 1858 wtype = info_bdq_free(dquots[cnt], number); 1859 if (wtype != QUOTA_NL_NOWARN) 1860 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1861 if (reserve) 1862 dquot_free_reserved_space(dquots[cnt], number); 1863 else 1864 dquot_decr_space(dquots[cnt], number); 1865 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1866 } 1867 if (reserve) 1868 *inode_reserved_space(inode) -= number; 1869 else 1870 __inode_sub_bytes(inode, number); 1871 spin_unlock(&inode->i_lock); 1872 1873 if (reserve) 1874 goto out_unlock; 1875 mark_all_dquot_dirty(dquots); 1876 out_unlock: 1877 srcu_read_unlock(&dquot_srcu, index); 1878 flush_warnings(warn); 1879 } 1880 EXPORT_SYMBOL(__dquot_free_space); 1881 1882 /* 1883 * This operation can block, but only after everything is updated 1884 */ 1885 void dquot_free_inode(struct inode *inode) 1886 { 1887 unsigned int cnt; 1888 struct dquot_warn warn[MAXQUOTAS]; 1889 struct dquot * const *dquots; 1890 int index; 1891 1892 if (!dquot_active(inode)) 1893 return; 1894 1895 dquots = i_dquot(inode); 1896 index = srcu_read_lock(&dquot_srcu); 1897 spin_lock(&inode->i_lock); 1898 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1899 int wtype; 1900 1901 warn[cnt].w_type = QUOTA_NL_NOWARN; 1902 if (!dquots[cnt]) 1903 continue; 1904 spin_lock(&dquots[cnt]->dq_dqb_lock); 1905 wtype = info_idq_free(dquots[cnt], 1); 1906 if (wtype != QUOTA_NL_NOWARN) 1907 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1908 dquot_decr_inodes(dquots[cnt], 1); 1909 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1910 } 1911 spin_unlock(&inode->i_lock); 1912 mark_all_dquot_dirty(dquots); 1913 srcu_read_unlock(&dquot_srcu, index); 1914 flush_warnings(warn); 1915 } 1916 EXPORT_SYMBOL(dquot_free_inode); 1917 1918 /* 1919 * Transfer the number of inode and blocks from one diskquota to an other. 1920 * On success, dquot references in transfer_to are consumed and references 1921 * to original dquots that need to be released are placed there. On failure, 1922 * references are kept untouched. 1923 * 1924 * This operation can block, but only after everything is updated 1925 * A transaction must be started when entering this function. 1926 * 1927 * We are holding reference on transfer_from & transfer_to, no need to 1928 * protect them by srcu_read_lock(). 1929 */ 1930 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1931 { 1932 qsize_t cur_space; 1933 qsize_t rsv_space = 0; 1934 qsize_t inode_usage = 1; 1935 struct dquot *transfer_from[MAXQUOTAS] = {}; 1936 int cnt, ret = 0; 1937 char is_valid[MAXQUOTAS] = {}; 1938 struct dquot_warn warn_to[MAXQUOTAS]; 1939 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1940 struct dquot_warn warn_from_space[MAXQUOTAS]; 1941 1942 if (IS_NOQUOTA(inode)) 1943 return 0; 1944 1945 if (inode->i_sb->dq_op->get_inode_usage) { 1946 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1947 if (ret) 1948 return ret; 1949 } 1950 1951 /* Initialize the arrays */ 1952 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1953 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1954 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1955 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1956 } 1957 1958 spin_lock(&dq_data_lock); 1959 spin_lock(&inode->i_lock); 1960 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1961 spin_unlock(&inode->i_lock); 1962 spin_unlock(&dq_data_lock); 1963 return 0; 1964 } 1965 cur_space = __inode_get_bytes(inode); 1966 rsv_space = __inode_get_rsv_space(inode); 1967 /* 1968 * Build the transfer_from list, check limits, and update usage in 1969 * the target structures. 1970 */ 1971 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1972 /* 1973 * Skip changes for same uid or gid or for turned off quota-type. 1974 */ 1975 if (!transfer_to[cnt]) 1976 continue; 1977 /* Avoid races with quotaoff() */ 1978 if (!sb_has_quota_active(inode->i_sb, cnt)) 1979 continue; 1980 is_valid[cnt] = 1; 1981 transfer_from[cnt] = i_dquot(inode)[cnt]; 1982 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 1983 &warn_to[cnt]); 1984 if (ret) 1985 goto over_quota; 1986 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 0, 1987 &warn_to[cnt]); 1988 if (ret) { 1989 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 1990 dquot_decr_inodes(transfer_to[cnt], inode_usage); 1991 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 1992 goto over_quota; 1993 } 1994 } 1995 1996 /* Decrease usage for source structures and update quota pointers */ 1997 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1998 if (!is_valid[cnt]) 1999 continue; 2000 /* Due to IO error we might not have transfer_from[] structure */ 2001 if (transfer_from[cnt]) { 2002 int wtype; 2003 2004 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2005 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2006 if (wtype != QUOTA_NL_NOWARN) 2007 prepare_warning(&warn_from_inodes[cnt], 2008 transfer_from[cnt], wtype); 2009 wtype = info_bdq_free(transfer_from[cnt], 2010 cur_space + rsv_space); 2011 if (wtype != QUOTA_NL_NOWARN) 2012 prepare_warning(&warn_from_space[cnt], 2013 transfer_from[cnt], wtype); 2014 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2015 dquot_decr_space(transfer_from[cnt], cur_space); 2016 dquot_free_reserved_space(transfer_from[cnt], 2017 rsv_space); 2018 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2019 } 2020 i_dquot(inode)[cnt] = transfer_to[cnt]; 2021 } 2022 spin_unlock(&inode->i_lock); 2023 spin_unlock(&dq_data_lock); 2024 2025 mark_all_dquot_dirty(transfer_from); 2026 mark_all_dquot_dirty(transfer_to); 2027 flush_warnings(warn_to); 2028 flush_warnings(warn_from_inodes); 2029 flush_warnings(warn_from_space); 2030 /* Pass back references to put */ 2031 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2032 if (is_valid[cnt]) 2033 transfer_to[cnt] = transfer_from[cnt]; 2034 return 0; 2035 over_quota: 2036 /* Back out changes we already did */ 2037 for (cnt--; cnt >= 0; cnt--) { 2038 if (!is_valid[cnt]) 2039 continue; 2040 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2041 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2042 dquot_decr_space(transfer_to[cnt], cur_space); 2043 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2044 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2045 } 2046 spin_unlock(&inode->i_lock); 2047 spin_unlock(&dq_data_lock); 2048 flush_warnings(warn_to); 2049 return ret; 2050 } 2051 EXPORT_SYMBOL(__dquot_transfer); 2052 2053 /* Wrapper for transferring ownership of an inode for uid/gid only 2054 * Called from FSXXX_setattr() 2055 */ 2056 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2057 { 2058 struct dquot *transfer_to[MAXQUOTAS] = {}; 2059 struct dquot *dquot; 2060 struct super_block *sb = inode->i_sb; 2061 int ret; 2062 2063 if (!dquot_active(inode)) 2064 return 0; 2065 2066 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2067 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2068 if (IS_ERR(dquot)) { 2069 if (PTR_ERR(dquot) != -ESRCH) { 2070 ret = PTR_ERR(dquot); 2071 goto out_put; 2072 } 2073 dquot = NULL; 2074 } 2075 transfer_to[USRQUOTA] = dquot; 2076 } 2077 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2078 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2079 if (IS_ERR(dquot)) { 2080 if (PTR_ERR(dquot) != -ESRCH) { 2081 ret = PTR_ERR(dquot); 2082 goto out_put; 2083 } 2084 dquot = NULL; 2085 } 2086 transfer_to[GRPQUOTA] = dquot; 2087 } 2088 ret = __dquot_transfer(inode, transfer_to); 2089 out_put: 2090 dqput_all(transfer_to); 2091 return ret; 2092 } 2093 EXPORT_SYMBOL(dquot_transfer); 2094 2095 /* 2096 * Write info of quota file to disk 2097 */ 2098 int dquot_commit_info(struct super_block *sb, int type) 2099 { 2100 struct quota_info *dqopt = sb_dqopt(sb); 2101 2102 return dqopt->ops[type]->write_file_info(sb, type); 2103 } 2104 EXPORT_SYMBOL(dquot_commit_info); 2105 2106 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2107 { 2108 struct quota_info *dqopt = sb_dqopt(sb); 2109 2110 if (!sb_has_quota_active(sb, qid->type)) 2111 return -ESRCH; 2112 if (!dqopt->ops[qid->type]->get_next_id) 2113 return -ENOSYS; 2114 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2115 } 2116 EXPORT_SYMBOL(dquot_get_next_id); 2117 2118 /* 2119 * Definitions of diskquota operations. 2120 */ 2121 const struct dquot_operations dquot_operations = { 2122 .write_dquot = dquot_commit, 2123 .acquire_dquot = dquot_acquire, 2124 .release_dquot = dquot_release, 2125 .mark_dirty = dquot_mark_dquot_dirty, 2126 .write_info = dquot_commit_info, 2127 .alloc_dquot = dquot_alloc, 2128 .destroy_dquot = dquot_destroy, 2129 .get_next_id = dquot_get_next_id, 2130 }; 2131 EXPORT_SYMBOL(dquot_operations); 2132 2133 /* 2134 * Generic helper for ->open on filesystems supporting disk quotas. 2135 */ 2136 int dquot_file_open(struct inode *inode, struct file *file) 2137 { 2138 int error; 2139 2140 error = generic_file_open(inode, file); 2141 if (!error && (file->f_mode & FMODE_WRITE)) 2142 dquot_initialize(inode); 2143 return error; 2144 } 2145 EXPORT_SYMBOL(dquot_file_open); 2146 2147 /* 2148 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2149 */ 2150 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2151 { 2152 int cnt, ret = 0; 2153 struct quota_info *dqopt = sb_dqopt(sb); 2154 struct inode *toputinode[MAXQUOTAS]; 2155 2156 /* s_umount should be held in exclusive mode */ 2157 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2158 up_read(&sb->s_umount); 2159 2160 /* Cannot turn off usage accounting without turning off limits, or 2161 * suspend quotas and simultaneously turn quotas off. */ 2162 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2163 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2164 DQUOT_USAGE_ENABLED))) 2165 return -EINVAL; 2166 2167 /* 2168 * Skip everything if there's nothing to do. We have to do this because 2169 * sometimes we are called when fill_super() failed and calling 2170 * sync_fs() in such cases does no good. 2171 */ 2172 if (!sb_any_quota_loaded(sb)) 2173 return 0; 2174 2175 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2176 toputinode[cnt] = NULL; 2177 if (type != -1 && cnt != type) 2178 continue; 2179 if (!sb_has_quota_loaded(sb, cnt)) 2180 continue; 2181 2182 if (flags & DQUOT_SUSPENDED) { 2183 spin_lock(&dq_state_lock); 2184 dqopt->flags |= 2185 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2186 spin_unlock(&dq_state_lock); 2187 } else { 2188 spin_lock(&dq_state_lock); 2189 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2190 /* Turning off suspended quotas? */ 2191 if (!sb_has_quota_loaded(sb, cnt) && 2192 sb_has_quota_suspended(sb, cnt)) { 2193 dqopt->flags &= ~dquot_state_flag( 2194 DQUOT_SUSPENDED, cnt); 2195 spin_unlock(&dq_state_lock); 2196 iput(dqopt->files[cnt]); 2197 dqopt->files[cnt] = NULL; 2198 continue; 2199 } 2200 spin_unlock(&dq_state_lock); 2201 } 2202 2203 /* We still have to keep quota loaded? */ 2204 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2205 continue; 2206 2207 /* Note: these are blocking operations */ 2208 drop_dquot_ref(sb, cnt); 2209 invalidate_dquots(sb, cnt); 2210 /* 2211 * Now all dquots should be invalidated, all writes done so we 2212 * should be only users of the info. No locks needed. 2213 */ 2214 if (info_dirty(&dqopt->info[cnt])) 2215 sb->dq_op->write_info(sb, cnt); 2216 if (dqopt->ops[cnt]->free_file_info) 2217 dqopt->ops[cnt]->free_file_info(sb, cnt); 2218 put_quota_format(dqopt->info[cnt].dqi_format); 2219 2220 toputinode[cnt] = dqopt->files[cnt]; 2221 if (!sb_has_quota_loaded(sb, cnt)) 2222 dqopt->files[cnt] = NULL; 2223 dqopt->info[cnt].dqi_flags = 0; 2224 dqopt->info[cnt].dqi_igrace = 0; 2225 dqopt->info[cnt].dqi_bgrace = 0; 2226 dqopt->ops[cnt] = NULL; 2227 } 2228 2229 /* Skip syncing and setting flags if quota files are hidden */ 2230 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2231 goto put_inodes; 2232 2233 /* Sync the superblock so that buffers with quota data are written to 2234 * disk (and so userspace sees correct data afterwards). */ 2235 if (sb->s_op->sync_fs) 2236 sb->s_op->sync_fs(sb, 1); 2237 sync_blockdev(sb->s_bdev); 2238 /* Now the quota files are just ordinary files and we can set the 2239 * inode flags back. Moreover we discard the pagecache so that 2240 * userspace sees the writes we did bypassing the pagecache. We 2241 * must also discard the blockdev buffers so that we see the 2242 * changes done by userspace on the next quotaon() */ 2243 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2244 /* This can happen when suspending quotas on remount-ro... */ 2245 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { 2246 inode_lock(toputinode[cnt]); 2247 toputinode[cnt]->i_flags &= ~S_NOQUOTA; 2248 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 2249 inode_unlock(toputinode[cnt]); 2250 mark_inode_dirty_sync(toputinode[cnt]); 2251 } 2252 if (sb->s_bdev) 2253 invalidate_bdev(sb->s_bdev); 2254 put_inodes: 2255 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2256 if (toputinode[cnt]) { 2257 /* On remount RO, we keep the inode pointer so that we 2258 * can reenable quota on the subsequent remount RW. We 2259 * have to check 'flags' variable and not use sb_has_ 2260 * function because another quotaon / quotaoff could 2261 * change global state before we got here. We refuse 2262 * to suspend quotas when there is pending delete on 2263 * the quota file... */ 2264 if (!(flags & DQUOT_SUSPENDED)) 2265 iput(toputinode[cnt]); 2266 else if (!toputinode[cnt]->i_nlink) 2267 ret = -EBUSY; 2268 } 2269 return ret; 2270 } 2271 EXPORT_SYMBOL(dquot_disable); 2272 2273 int dquot_quota_off(struct super_block *sb, int type) 2274 { 2275 return dquot_disable(sb, type, 2276 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2277 } 2278 EXPORT_SYMBOL(dquot_quota_off); 2279 2280 /* 2281 * Turn quotas on on a device 2282 */ 2283 2284 /* 2285 * Helper function to turn quotas on when we already have the inode of 2286 * quota file and no quota information is loaded. 2287 */ 2288 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2289 unsigned int flags) 2290 { 2291 struct quota_format_type *fmt = find_quota_format(format_id); 2292 struct super_block *sb = inode->i_sb; 2293 struct quota_info *dqopt = sb_dqopt(sb); 2294 int error; 2295 2296 if (!fmt) 2297 return -ESRCH; 2298 if (!S_ISREG(inode->i_mode)) { 2299 error = -EACCES; 2300 goto out_fmt; 2301 } 2302 if (IS_RDONLY(inode)) { 2303 error = -EROFS; 2304 goto out_fmt; 2305 } 2306 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2307 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2308 error = -EINVAL; 2309 goto out_fmt; 2310 } 2311 /* Filesystems outside of init_user_ns not yet supported */ 2312 if (sb->s_user_ns != &init_user_ns) { 2313 error = -EINVAL; 2314 goto out_fmt; 2315 } 2316 /* Usage always has to be set... */ 2317 if (!(flags & DQUOT_USAGE_ENABLED)) { 2318 error = -EINVAL; 2319 goto out_fmt; 2320 } 2321 if (sb_has_quota_loaded(sb, type)) { 2322 error = -EBUSY; 2323 goto out_fmt; 2324 } 2325 2326 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2327 /* As we bypass the pagecache we must now flush all the 2328 * dirty data and invalidate caches so that kernel sees 2329 * changes from userspace. It is not enough to just flush 2330 * the quota file since if blocksize < pagesize, invalidation 2331 * of the cache could fail because of other unrelated dirty 2332 * data */ 2333 sync_filesystem(sb); 2334 invalidate_bdev(sb->s_bdev); 2335 } 2336 2337 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2338 /* We don't want quota and atime on quota files (deadlocks 2339 * possible) Also nobody should write to the file - we use 2340 * special IO operations which ignore the immutable bit. */ 2341 inode_lock(inode); 2342 inode->i_flags |= S_NOQUOTA; 2343 inode_unlock(inode); 2344 /* 2345 * When S_NOQUOTA is set, remove dquot references as no more 2346 * references can be added 2347 */ 2348 __dquot_drop(inode); 2349 } 2350 2351 error = -EIO; 2352 dqopt->files[type] = igrab(inode); 2353 if (!dqopt->files[type]) 2354 goto out_file_flags; 2355 error = -EINVAL; 2356 if (!fmt->qf_ops->check_quota_file(sb, type)) 2357 goto out_file_init; 2358 2359 dqopt->ops[type] = fmt->qf_ops; 2360 dqopt->info[type].dqi_format = fmt; 2361 dqopt->info[type].dqi_fmt_id = format_id; 2362 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2363 error = dqopt->ops[type]->read_file_info(sb, type); 2364 if (error < 0) 2365 goto out_file_init; 2366 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2367 spin_lock(&dq_data_lock); 2368 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2369 spin_unlock(&dq_data_lock); 2370 } 2371 spin_lock(&dq_state_lock); 2372 dqopt->flags |= dquot_state_flag(flags, type); 2373 spin_unlock(&dq_state_lock); 2374 2375 add_dquot_ref(sb, type); 2376 2377 return 0; 2378 2379 out_file_init: 2380 dqopt->files[type] = NULL; 2381 iput(inode); 2382 out_file_flags: 2383 inode_lock(inode); 2384 inode->i_flags &= ~S_NOQUOTA; 2385 inode_unlock(inode); 2386 out_fmt: 2387 put_quota_format(fmt); 2388 2389 return error; 2390 } 2391 2392 /* Reenable quotas on remount RW */ 2393 int dquot_resume(struct super_block *sb, int type) 2394 { 2395 struct quota_info *dqopt = sb_dqopt(sb); 2396 struct inode *inode; 2397 int ret = 0, cnt; 2398 unsigned int flags; 2399 2400 /* s_umount should be held in exclusive mode */ 2401 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2402 up_read(&sb->s_umount); 2403 2404 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2405 if (type != -1 && cnt != type) 2406 continue; 2407 if (!sb_has_quota_suspended(sb, cnt)) 2408 continue; 2409 2410 inode = dqopt->files[cnt]; 2411 dqopt->files[cnt] = NULL; 2412 spin_lock(&dq_state_lock); 2413 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2414 DQUOT_LIMITS_ENABLED, 2415 cnt); 2416 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2417 spin_unlock(&dq_state_lock); 2418 2419 flags = dquot_generic_flag(flags, cnt); 2420 ret = vfs_load_quota_inode(inode, cnt, 2421 dqopt->info[cnt].dqi_fmt_id, flags); 2422 iput(inode); 2423 } 2424 2425 return ret; 2426 } 2427 EXPORT_SYMBOL(dquot_resume); 2428 2429 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2430 const struct path *path) 2431 { 2432 int error = security_quota_on(path->dentry); 2433 if (error) 2434 return error; 2435 /* Quota file not on the same filesystem? */ 2436 if (path->dentry->d_sb != sb) 2437 error = -EXDEV; 2438 else 2439 error = vfs_load_quota_inode(d_inode(path->dentry), type, 2440 format_id, DQUOT_USAGE_ENABLED | 2441 DQUOT_LIMITS_ENABLED); 2442 return error; 2443 } 2444 EXPORT_SYMBOL(dquot_quota_on); 2445 2446 /* 2447 * More powerful function for turning on quotas allowing setting 2448 * of individual quota flags 2449 */ 2450 int dquot_enable(struct inode *inode, int type, int format_id, 2451 unsigned int flags) 2452 { 2453 struct super_block *sb = inode->i_sb; 2454 2455 /* Just unsuspend quotas? */ 2456 BUG_ON(flags & DQUOT_SUSPENDED); 2457 /* s_umount should be held in exclusive mode */ 2458 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2459 up_read(&sb->s_umount); 2460 2461 if (!flags) 2462 return 0; 2463 /* Just updating flags needed? */ 2464 if (sb_has_quota_loaded(sb, type)) { 2465 if (flags & DQUOT_USAGE_ENABLED && 2466 sb_has_quota_usage_enabled(sb, type)) 2467 return -EBUSY; 2468 if (flags & DQUOT_LIMITS_ENABLED && 2469 sb_has_quota_limits_enabled(sb, type)) 2470 return -EBUSY; 2471 spin_lock(&dq_state_lock); 2472 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2473 spin_unlock(&dq_state_lock); 2474 return 0; 2475 } 2476 2477 return vfs_load_quota_inode(inode, type, format_id, flags); 2478 } 2479 EXPORT_SYMBOL(dquot_enable); 2480 2481 /* 2482 * This function is used when filesystem needs to initialize quotas 2483 * during mount time. 2484 */ 2485 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2486 int format_id, int type) 2487 { 2488 struct dentry *dentry; 2489 int error; 2490 2491 dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2492 if (IS_ERR(dentry)) 2493 return PTR_ERR(dentry); 2494 2495 if (d_really_is_negative(dentry)) { 2496 error = -ENOENT; 2497 goto out; 2498 } 2499 2500 error = security_quota_on(dentry); 2501 if (!error) 2502 error = vfs_load_quota_inode(d_inode(dentry), type, format_id, 2503 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2504 2505 out: 2506 dput(dentry); 2507 return error; 2508 } 2509 EXPORT_SYMBOL(dquot_quota_on_mount); 2510 2511 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2512 { 2513 int ret; 2514 int type; 2515 struct quota_info *dqopt = sb_dqopt(sb); 2516 2517 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2518 return -ENOSYS; 2519 /* Accounting cannot be turned on while fs is mounted */ 2520 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2521 if (!flags) 2522 return -EINVAL; 2523 for (type = 0; type < MAXQUOTAS; type++) { 2524 if (!(flags & qtype_enforce_flag(type))) 2525 continue; 2526 /* Can't enforce without accounting */ 2527 if (!sb_has_quota_usage_enabled(sb, type)) 2528 return -EINVAL; 2529 ret = dquot_enable(dqopt->files[type], type, 2530 dqopt->info[type].dqi_fmt_id, 2531 DQUOT_LIMITS_ENABLED); 2532 if (ret < 0) 2533 goto out_err; 2534 } 2535 return 0; 2536 out_err: 2537 /* Backout enforcement enablement we already did */ 2538 for (type--; type >= 0; type--) { 2539 if (flags & qtype_enforce_flag(type)) 2540 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2541 } 2542 /* Error code translation for better compatibility with XFS */ 2543 if (ret == -EBUSY) 2544 ret = -EEXIST; 2545 return ret; 2546 } 2547 2548 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2549 { 2550 int ret; 2551 int type; 2552 struct quota_info *dqopt = sb_dqopt(sb); 2553 2554 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2555 return -ENOSYS; 2556 /* 2557 * We don't support turning off accounting via quotactl. In principle 2558 * quota infrastructure can do this but filesystems don't expect 2559 * userspace to be able to do it. 2560 */ 2561 if (flags & 2562 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2563 return -EOPNOTSUPP; 2564 2565 /* Filter out limits not enabled */ 2566 for (type = 0; type < MAXQUOTAS; type++) 2567 if (!sb_has_quota_limits_enabled(sb, type)) 2568 flags &= ~qtype_enforce_flag(type); 2569 /* Nothing left? */ 2570 if (!flags) 2571 return -EEXIST; 2572 for (type = 0; type < MAXQUOTAS; type++) { 2573 if (flags & qtype_enforce_flag(type)) { 2574 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2575 if (ret < 0) 2576 goto out_err; 2577 } 2578 } 2579 return 0; 2580 out_err: 2581 /* Backout enforcement disabling we already did */ 2582 for (type--; type >= 0; type--) { 2583 if (flags & qtype_enforce_flag(type)) 2584 dquot_enable(dqopt->files[type], type, 2585 dqopt->info[type].dqi_fmt_id, 2586 DQUOT_LIMITS_ENABLED); 2587 } 2588 return ret; 2589 } 2590 2591 /* Generic routine for getting common part of quota structure */ 2592 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2593 { 2594 struct mem_dqblk *dm = &dquot->dq_dqb; 2595 2596 memset(di, 0, sizeof(*di)); 2597 spin_lock(&dquot->dq_dqb_lock); 2598 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2599 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2600 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2601 di->d_ino_softlimit = dm->dqb_isoftlimit; 2602 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2603 di->d_ino_count = dm->dqb_curinodes; 2604 di->d_spc_timer = dm->dqb_btime; 2605 di->d_ino_timer = dm->dqb_itime; 2606 spin_unlock(&dquot->dq_dqb_lock); 2607 } 2608 2609 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2610 struct qc_dqblk *di) 2611 { 2612 struct dquot *dquot; 2613 2614 dquot = dqget(sb, qid); 2615 if (IS_ERR(dquot)) 2616 return PTR_ERR(dquot); 2617 do_get_dqblk(dquot, di); 2618 dqput(dquot); 2619 2620 return 0; 2621 } 2622 EXPORT_SYMBOL(dquot_get_dqblk); 2623 2624 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2625 struct qc_dqblk *di) 2626 { 2627 struct dquot *dquot; 2628 int err; 2629 2630 if (!sb->dq_op->get_next_id) 2631 return -ENOSYS; 2632 err = sb->dq_op->get_next_id(sb, qid); 2633 if (err < 0) 2634 return err; 2635 dquot = dqget(sb, *qid); 2636 if (IS_ERR(dquot)) 2637 return PTR_ERR(dquot); 2638 do_get_dqblk(dquot, di); 2639 dqput(dquot); 2640 2641 return 0; 2642 } 2643 EXPORT_SYMBOL(dquot_get_next_dqblk); 2644 2645 #define VFS_QC_MASK \ 2646 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2647 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2648 QC_SPC_TIMER | QC_INO_TIMER) 2649 2650 /* Generic routine for setting common part of quota structure */ 2651 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2652 { 2653 struct mem_dqblk *dm = &dquot->dq_dqb; 2654 int check_blim = 0, check_ilim = 0; 2655 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2656 2657 if (di->d_fieldmask & ~VFS_QC_MASK) 2658 return -EINVAL; 2659 2660 if (((di->d_fieldmask & QC_SPC_SOFT) && 2661 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2662 ((di->d_fieldmask & QC_SPC_HARD) && 2663 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2664 ((di->d_fieldmask & QC_INO_SOFT) && 2665 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2666 ((di->d_fieldmask & QC_INO_HARD) && 2667 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2668 return -ERANGE; 2669 2670 spin_lock(&dquot->dq_dqb_lock); 2671 if (di->d_fieldmask & QC_SPACE) { 2672 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2673 check_blim = 1; 2674 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2675 } 2676 2677 if (di->d_fieldmask & QC_SPC_SOFT) 2678 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2679 if (di->d_fieldmask & QC_SPC_HARD) 2680 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2681 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2682 check_blim = 1; 2683 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2684 } 2685 2686 if (di->d_fieldmask & QC_INO_COUNT) { 2687 dm->dqb_curinodes = di->d_ino_count; 2688 check_ilim = 1; 2689 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2690 } 2691 2692 if (di->d_fieldmask & QC_INO_SOFT) 2693 dm->dqb_isoftlimit = di->d_ino_softlimit; 2694 if (di->d_fieldmask & QC_INO_HARD) 2695 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2696 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2697 check_ilim = 1; 2698 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2699 } 2700 2701 if (di->d_fieldmask & QC_SPC_TIMER) { 2702 dm->dqb_btime = di->d_spc_timer; 2703 check_blim = 1; 2704 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2705 } 2706 2707 if (di->d_fieldmask & QC_INO_TIMER) { 2708 dm->dqb_itime = di->d_ino_timer; 2709 check_ilim = 1; 2710 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2711 } 2712 2713 if (check_blim) { 2714 if (!dm->dqb_bsoftlimit || 2715 dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) { 2716 dm->dqb_btime = 0; 2717 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2718 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2719 /* Set grace only if user hasn't provided his own... */ 2720 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2721 } 2722 if (check_ilim) { 2723 if (!dm->dqb_isoftlimit || 2724 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2725 dm->dqb_itime = 0; 2726 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2727 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2728 /* Set grace only if user hasn't provided his own... */ 2729 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2730 } 2731 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2732 dm->dqb_isoftlimit) 2733 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2734 else 2735 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2736 spin_unlock(&dquot->dq_dqb_lock); 2737 mark_dquot_dirty(dquot); 2738 2739 return 0; 2740 } 2741 2742 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2743 struct qc_dqblk *di) 2744 { 2745 struct dquot *dquot; 2746 int rc; 2747 2748 dquot = dqget(sb, qid); 2749 if (IS_ERR(dquot)) { 2750 rc = PTR_ERR(dquot); 2751 goto out; 2752 } 2753 rc = do_set_dqblk(dquot, di); 2754 dqput(dquot); 2755 out: 2756 return rc; 2757 } 2758 EXPORT_SYMBOL(dquot_set_dqblk); 2759 2760 /* Generic routine for getting common part of quota file information */ 2761 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2762 { 2763 struct mem_dqinfo *mi; 2764 struct qc_type_state *tstate; 2765 struct quota_info *dqopt = sb_dqopt(sb); 2766 int type; 2767 2768 memset(state, 0, sizeof(*state)); 2769 for (type = 0; type < MAXQUOTAS; type++) { 2770 if (!sb_has_quota_active(sb, type)) 2771 continue; 2772 tstate = state->s_state + type; 2773 mi = sb_dqopt(sb)->info + type; 2774 tstate->flags = QCI_ACCT_ENABLED; 2775 spin_lock(&dq_data_lock); 2776 if (mi->dqi_flags & DQF_SYS_FILE) 2777 tstate->flags |= QCI_SYSFILE; 2778 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2779 tstate->flags |= QCI_ROOT_SQUASH; 2780 if (sb_has_quota_limits_enabled(sb, type)) 2781 tstate->flags |= QCI_LIMITS_ENFORCED; 2782 tstate->spc_timelimit = mi->dqi_bgrace; 2783 tstate->ino_timelimit = mi->dqi_igrace; 2784 tstate->ino = dqopt->files[type]->i_ino; 2785 tstate->blocks = dqopt->files[type]->i_blocks; 2786 tstate->nextents = 1; /* We don't know... */ 2787 spin_unlock(&dq_data_lock); 2788 } 2789 return 0; 2790 } 2791 EXPORT_SYMBOL(dquot_get_state); 2792 2793 /* Generic routine for setting common part of quota file information */ 2794 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2795 { 2796 struct mem_dqinfo *mi; 2797 int err = 0; 2798 2799 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2800 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2801 return -EINVAL; 2802 if (!sb_has_quota_active(sb, type)) 2803 return -ESRCH; 2804 mi = sb_dqopt(sb)->info + type; 2805 if (ii->i_fieldmask & QC_FLAGS) { 2806 if ((ii->i_flags & QCI_ROOT_SQUASH && 2807 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2808 return -EINVAL; 2809 } 2810 spin_lock(&dq_data_lock); 2811 if (ii->i_fieldmask & QC_SPC_TIMER) 2812 mi->dqi_bgrace = ii->i_spc_timelimit; 2813 if (ii->i_fieldmask & QC_INO_TIMER) 2814 mi->dqi_igrace = ii->i_ino_timelimit; 2815 if (ii->i_fieldmask & QC_FLAGS) { 2816 if (ii->i_flags & QCI_ROOT_SQUASH) 2817 mi->dqi_flags |= DQF_ROOT_SQUASH; 2818 else 2819 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2820 } 2821 spin_unlock(&dq_data_lock); 2822 mark_info_dirty(sb, type); 2823 /* Force write to disk */ 2824 sb->dq_op->write_info(sb, type); 2825 return err; 2826 } 2827 EXPORT_SYMBOL(dquot_set_dqinfo); 2828 2829 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2830 .quota_enable = dquot_quota_enable, 2831 .quota_disable = dquot_quota_disable, 2832 .quota_sync = dquot_quota_sync, 2833 .get_state = dquot_get_state, 2834 .set_info = dquot_set_dqinfo, 2835 .get_dqblk = dquot_get_dqblk, 2836 .get_nextdqblk = dquot_get_next_dqblk, 2837 .set_dqblk = dquot_set_dqblk 2838 }; 2839 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2840 2841 static int do_proc_dqstats(struct ctl_table *table, int write, 2842 void __user *buffer, size_t *lenp, loff_t *ppos) 2843 { 2844 unsigned int type = (int *)table->data - dqstats.stat; 2845 2846 /* Update global table */ 2847 dqstats.stat[type] = 2848 percpu_counter_sum_positive(&dqstats.counter[type]); 2849 return proc_dointvec(table, write, buffer, lenp, ppos); 2850 } 2851 2852 static struct ctl_table fs_dqstats_table[] = { 2853 { 2854 .procname = "lookups", 2855 .data = &dqstats.stat[DQST_LOOKUPS], 2856 .maxlen = sizeof(int), 2857 .mode = 0444, 2858 .proc_handler = do_proc_dqstats, 2859 }, 2860 { 2861 .procname = "drops", 2862 .data = &dqstats.stat[DQST_DROPS], 2863 .maxlen = sizeof(int), 2864 .mode = 0444, 2865 .proc_handler = do_proc_dqstats, 2866 }, 2867 { 2868 .procname = "reads", 2869 .data = &dqstats.stat[DQST_READS], 2870 .maxlen = sizeof(int), 2871 .mode = 0444, 2872 .proc_handler = do_proc_dqstats, 2873 }, 2874 { 2875 .procname = "writes", 2876 .data = &dqstats.stat[DQST_WRITES], 2877 .maxlen = sizeof(int), 2878 .mode = 0444, 2879 .proc_handler = do_proc_dqstats, 2880 }, 2881 { 2882 .procname = "cache_hits", 2883 .data = &dqstats.stat[DQST_CACHE_HITS], 2884 .maxlen = sizeof(int), 2885 .mode = 0444, 2886 .proc_handler = do_proc_dqstats, 2887 }, 2888 { 2889 .procname = "allocated_dquots", 2890 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2891 .maxlen = sizeof(int), 2892 .mode = 0444, 2893 .proc_handler = do_proc_dqstats, 2894 }, 2895 { 2896 .procname = "free_dquots", 2897 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2898 .maxlen = sizeof(int), 2899 .mode = 0444, 2900 .proc_handler = do_proc_dqstats, 2901 }, 2902 { 2903 .procname = "syncs", 2904 .data = &dqstats.stat[DQST_SYNCS], 2905 .maxlen = sizeof(int), 2906 .mode = 0444, 2907 .proc_handler = do_proc_dqstats, 2908 }, 2909 #ifdef CONFIG_PRINT_QUOTA_WARNING 2910 { 2911 .procname = "warnings", 2912 .data = &flag_print_warnings, 2913 .maxlen = sizeof(int), 2914 .mode = 0644, 2915 .proc_handler = proc_dointvec, 2916 }, 2917 #endif 2918 { }, 2919 }; 2920 2921 static struct ctl_table fs_table[] = { 2922 { 2923 .procname = "quota", 2924 .mode = 0555, 2925 .child = fs_dqstats_table, 2926 }, 2927 { }, 2928 }; 2929 2930 static struct ctl_table sys_table[] = { 2931 { 2932 .procname = "fs", 2933 .mode = 0555, 2934 .child = fs_table, 2935 }, 2936 { }, 2937 }; 2938 2939 static int __init dquot_init(void) 2940 { 2941 int i, ret; 2942 unsigned long nr_hash, order; 2943 2944 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2945 2946 register_sysctl_table(sys_table); 2947 2948 dquot_cachep = kmem_cache_create("dquot", 2949 sizeof(struct dquot), sizeof(unsigned long) * 4, 2950 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2951 SLAB_MEM_SPREAD|SLAB_PANIC), 2952 NULL); 2953 2954 order = 0; 2955 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2956 if (!dquot_hash) 2957 panic("Cannot create dquot hash table"); 2958 2959 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2960 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2961 if (ret) 2962 panic("Cannot create dquot stat counters"); 2963 } 2964 2965 /* Find power-of-two hlist_heads which can fit into allocation */ 2966 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2967 dq_hash_bits = 0; 2968 do { 2969 dq_hash_bits++; 2970 } while (nr_hash >> dq_hash_bits); 2971 dq_hash_bits--; 2972 2973 nr_hash = 1UL << dq_hash_bits; 2974 dq_hash_mask = nr_hash - 1; 2975 for (i = 0; i < nr_hash; i++) 2976 INIT_HLIST_HEAD(dquot_hash + i); 2977 2978 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2979 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2980 2981 register_shrinker(&dqcache_shrinker); 2982 2983 return 0; 2984 } 2985 fs_initcall(dquot_init); 2986