1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implementation of the diskquota system for the LINUX operating system. QUOTA 4 * is implemented using the BSD system call interface as the means of 5 * communication with the user level. This file contains the generic routines 6 * called by the different filesystems on allocation of an inode or block. 7 * These routines take care of the administration needed to have a consistent 8 * diskquota tracking system. The ideas of both user and group quotas are based 9 * on the Melbourne quota system as used on BSD derived systems. The internal 10 * implementation is based on one of the several variants of the LINUX 11 * inode-subsystem with added complexity of the diskquota system. 12 * 13 * Author: Marco van Wieringen <mvw@planets.elm.net> 14 * 15 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 16 * 17 * Revised list management to avoid races 18 * -- Bill Hawes, <whawes@star.net>, 9/98 19 * 20 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). 21 * As the consequence the locking was moved from dquot_decr_...(), 22 * dquot_incr_...() to calling functions. 23 * invalidate_dquots() now writes modified dquots. 24 * Serialized quota_off() and quota_on() for mount point. 25 * Fixed a few bugs in grow_dquots(). 26 * Fixed deadlock in write_dquot() - we no longer account quotas on 27 * quota files 28 * remove_dquot_ref() moved to inode.c - it now traverses through inodes 29 * add_dquot_ref() restarts after blocking 30 * Added check for bogus uid and fixed check for group in quotactl. 31 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99 32 * 33 * Used struct list_head instead of own list struct 34 * Invalidation of referenced dquots is no longer possible 35 * Improved free_dquots list management 36 * Quota and i_blocks are now updated in one place to avoid races 37 * Warnings are now delayed so we won't block in critical section 38 * Write updated not to require dquot lock 39 * Jan Kara, <jack@suse.cz>, 9/2000 40 * 41 * Added dynamic quota structure allocation 42 * Jan Kara <jack@suse.cz> 12/2000 43 * 44 * Rewritten quota interface. Implemented new quota format and 45 * formats registering. 46 * Jan Kara, <jack@suse.cz>, 2001,2002 47 * 48 * New SMP locking. 49 * Jan Kara, <jack@suse.cz>, 10/2002 50 * 51 * Added journalled quota support, fix lock inversion problems 52 * Jan Kara, <jack@suse.cz>, 2003,2004 53 * 54 * (C) Copyright 1994 - 1997 Marco van Wieringen 55 */ 56 57 #include <linux/errno.h> 58 #include <linux/kernel.h> 59 #include <linux/fs.h> 60 #include <linux/mount.h> 61 #include <linux/mm.h> 62 #include <linux/time.h> 63 #include <linux/types.h> 64 #include <linux/string.h> 65 #include <linux/fcntl.h> 66 #include <linux/stat.h> 67 #include <linux/tty.h> 68 #include <linux/file.h> 69 #include <linux/slab.h> 70 #include <linux/sysctl.h> 71 #include <linux/init.h> 72 #include <linux/module.h> 73 #include <linux/proc_fs.h> 74 #include <linux/security.h> 75 #include <linux/sched.h> 76 #include <linux/cred.h> 77 #include <linux/kmod.h> 78 #include <linux/namei.h> 79 #include <linux/capability.h> 80 #include <linux/quotaops.h> 81 #include <linux/blkdev.h> 82 #include "../internal.h" /* ugh */ 83 84 #include <linux/uaccess.h> 85 86 /* 87 * There are five quota SMP locks: 88 * * dq_list_lock protects all lists with quotas and quota formats. 89 * * dquot->dq_dqb_lock protects data from dq_dqb 90 * * inode->i_lock protects inode->i_blocks, i_bytes and also guards 91 * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that 92 * dquot_transfer() can stabilize amount it transfers 93 * * dq_data_lock protects mem_dqinfo structures and modifications of dquot 94 * pointers in the inode 95 * * dq_state_lock protects modifications of quota state (on quotaon and 96 * quotaoff) and readers who care about latest values take it as well. 97 * 98 * The spinlock ordering is hence: 99 * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, 100 * dq_list_lock > dq_state_lock 101 * 102 * Note that some things (eg. sb pointer, type, id) doesn't change during 103 * the life of the dquot structure and so needn't to be protected by a lock 104 * 105 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 106 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 107 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 108 * inode and before dropping dquot references to avoid use of dquots after 109 * they are freed. dq_data_lock is used to serialize the pointer setting and 110 * clearing operations. 111 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 112 * inode is a quota file). Functions adding pointers from inode to dquots have 113 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 114 * have to do all pointer modifications before dropping dq_data_lock. This makes 115 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 116 * then drops all pointers to dquots from an inode. 117 * 118 * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to 119 * memory (or space for it is being allocated) on the first dqget(), when it is 120 * being written out, and when it is being released on the last dqput(). The 121 * allocation and release operations are serialized by the dq_lock and by 122 * checking the use count in dquot_release(). 123 * 124 * Lock ordering (including related VFS locks) is the following: 125 * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem 126 */ 127 128 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 129 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 130 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 131 EXPORT_SYMBOL(dq_data_lock); 132 DEFINE_STATIC_SRCU(dquot_srcu); 133 134 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); 135 136 void __quota_error(struct super_block *sb, const char *func, 137 const char *fmt, ...) 138 { 139 if (printk_ratelimit()) { 140 va_list args; 141 struct va_format vaf; 142 143 va_start(args, fmt); 144 145 vaf.fmt = fmt; 146 vaf.va = &args; 147 148 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 149 sb->s_id, func, &vaf); 150 151 va_end(args); 152 } 153 } 154 EXPORT_SYMBOL(__quota_error); 155 156 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 157 static char *quotatypes[] = INITQFNAMES; 158 #endif 159 static struct quota_format_type *quota_formats; /* List of registered formats */ 160 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 161 162 /* SLAB cache for dquot structures */ 163 static struct kmem_cache *dquot_cachep; 164 165 int register_quota_format(struct quota_format_type *fmt) 166 { 167 spin_lock(&dq_list_lock); 168 fmt->qf_next = quota_formats; 169 quota_formats = fmt; 170 spin_unlock(&dq_list_lock); 171 return 0; 172 } 173 EXPORT_SYMBOL(register_quota_format); 174 175 void unregister_quota_format(struct quota_format_type *fmt) 176 { 177 struct quota_format_type **actqf; 178 179 spin_lock(&dq_list_lock); 180 for (actqf = "a_formats; *actqf && *actqf != fmt; 181 actqf = &(*actqf)->qf_next) 182 ; 183 if (*actqf) 184 *actqf = (*actqf)->qf_next; 185 spin_unlock(&dq_list_lock); 186 } 187 EXPORT_SYMBOL(unregister_quota_format); 188 189 static struct quota_format_type *find_quota_format(int id) 190 { 191 struct quota_format_type *actqf; 192 193 spin_lock(&dq_list_lock); 194 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 195 actqf = actqf->qf_next) 196 ; 197 if (!actqf || !try_module_get(actqf->qf_owner)) { 198 int qm; 199 200 spin_unlock(&dq_list_lock); 201 202 for (qm = 0; module_names[qm].qm_fmt_id && 203 module_names[qm].qm_fmt_id != id; qm++) 204 ; 205 if (!module_names[qm].qm_fmt_id || 206 request_module(module_names[qm].qm_mod_name)) 207 return NULL; 208 209 spin_lock(&dq_list_lock); 210 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 211 actqf = actqf->qf_next) 212 ; 213 if (actqf && !try_module_get(actqf->qf_owner)) 214 actqf = NULL; 215 } 216 spin_unlock(&dq_list_lock); 217 return actqf; 218 } 219 220 static void put_quota_format(struct quota_format_type *fmt) 221 { 222 module_put(fmt->qf_owner); 223 } 224 225 /* 226 * Dquot List Management: 227 * The quota code uses four lists for dquot management: the inuse_list, 228 * free_dquots, dqi_dirty_list, and dquot_hash[] array. A single dquot 229 * structure may be on some of those lists, depending on its current state. 230 * 231 * All dquots are placed to the end of inuse_list when first created, and this 232 * list is used for invalidate operation, which must look at every dquot. 233 * 234 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 235 * and this list is searched whenever we need an available dquot. Dquots are 236 * removed from the list as soon as they are used again, and 237 * dqstats.free_dquots gives the number of dquots on the list. When 238 * dquot is invalidated it's completely released from memory. 239 * 240 * Dirty dquots are added to the dqi_dirty_list of quota_info when mark 241 * dirtied, and this list is searched when writing dirty dquots back to 242 * quota file. Note that some filesystems do dirty dquot tracking on their 243 * own (e.g. in a journal) and thus don't use dqi_dirty_list. 244 * 245 * Dquots with a specific identity (device, type and id) are placed on 246 * one of the dquot_hash[] hash chains. The provides an efficient search 247 * mechanism to locate a specific dquot. 248 */ 249 250 static LIST_HEAD(inuse_list); 251 static LIST_HEAD(free_dquots); 252 static unsigned int dq_hash_bits, dq_hash_mask; 253 static struct hlist_head *dquot_hash; 254 255 struct dqstats dqstats; 256 EXPORT_SYMBOL(dqstats); 257 258 static qsize_t inode_get_rsv_space(struct inode *inode); 259 static qsize_t __inode_get_rsv_space(struct inode *inode); 260 static int __dquot_initialize(struct inode *inode, int type); 261 262 static inline unsigned int 263 hashfn(const struct super_block *sb, struct kqid qid) 264 { 265 unsigned int id = from_kqid(&init_user_ns, qid); 266 int type = qid.type; 267 unsigned long tmp; 268 269 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 270 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 271 } 272 273 /* 274 * Following list functions expect dq_list_lock to be held 275 */ 276 static inline void insert_dquot_hash(struct dquot *dquot) 277 { 278 struct hlist_head *head; 279 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 280 hlist_add_head(&dquot->dq_hash, head); 281 } 282 283 static inline void remove_dquot_hash(struct dquot *dquot) 284 { 285 hlist_del_init(&dquot->dq_hash); 286 } 287 288 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 289 struct kqid qid) 290 { 291 struct dquot *dquot; 292 293 hlist_for_each_entry(dquot, dquot_hash+hashent, dq_hash) 294 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 295 return dquot; 296 297 return NULL; 298 } 299 300 /* Add a dquot to the tail of the free list */ 301 static inline void put_dquot_last(struct dquot *dquot) 302 { 303 list_add_tail(&dquot->dq_free, &free_dquots); 304 dqstats_inc(DQST_FREE_DQUOTS); 305 } 306 307 static inline void remove_free_dquot(struct dquot *dquot) 308 { 309 if (list_empty(&dquot->dq_free)) 310 return; 311 list_del_init(&dquot->dq_free); 312 dqstats_dec(DQST_FREE_DQUOTS); 313 } 314 315 static inline void put_inuse(struct dquot *dquot) 316 { 317 /* We add to the back of inuse list so we don't have to restart 318 * when traversing this list and we block */ 319 list_add_tail(&dquot->dq_inuse, &inuse_list); 320 dqstats_inc(DQST_ALLOC_DQUOTS); 321 } 322 323 static inline void remove_inuse(struct dquot *dquot) 324 { 325 dqstats_dec(DQST_ALLOC_DQUOTS); 326 list_del(&dquot->dq_inuse); 327 } 328 /* 329 * End of list functions needing dq_list_lock 330 */ 331 332 static void wait_on_dquot(struct dquot *dquot) 333 { 334 mutex_lock(&dquot->dq_lock); 335 mutex_unlock(&dquot->dq_lock); 336 } 337 338 static inline int dquot_dirty(struct dquot *dquot) 339 { 340 return test_bit(DQ_MOD_B, &dquot->dq_flags); 341 } 342 343 static inline int mark_dquot_dirty(struct dquot *dquot) 344 { 345 return dquot->dq_sb->dq_op->mark_dirty(dquot); 346 } 347 348 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 349 int dquot_mark_dquot_dirty(struct dquot *dquot) 350 { 351 int ret = 1; 352 353 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 354 return 0; 355 356 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 357 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 358 359 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 360 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 361 return 1; 362 363 spin_lock(&dq_list_lock); 364 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 365 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 366 info[dquot->dq_id.type].dqi_dirty_list); 367 ret = 0; 368 } 369 spin_unlock(&dq_list_lock); 370 return ret; 371 } 372 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 373 374 /* Dirtify all the dquots - this can block when journalling */ 375 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 376 { 377 int ret, err, cnt; 378 379 ret = err = 0; 380 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 381 if (dquot[cnt]) 382 /* Even in case of error we have to continue */ 383 ret = mark_dquot_dirty(dquot[cnt]); 384 if (!err) 385 err = ret; 386 } 387 return err; 388 } 389 390 static inline void dqput_all(struct dquot **dquot) 391 { 392 unsigned int cnt; 393 394 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 395 dqput(dquot[cnt]); 396 } 397 398 static inline int clear_dquot_dirty(struct dquot *dquot) 399 { 400 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 401 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 402 403 spin_lock(&dq_list_lock); 404 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 405 spin_unlock(&dq_list_lock); 406 return 0; 407 } 408 list_del_init(&dquot->dq_dirty); 409 spin_unlock(&dq_list_lock); 410 return 1; 411 } 412 413 void mark_info_dirty(struct super_block *sb, int type) 414 { 415 spin_lock(&dq_data_lock); 416 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 417 spin_unlock(&dq_data_lock); 418 } 419 EXPORT_SYMBOL(mark_info_dirty); 420 421 /* 422 * Read dquot from disk and alloc space for it 423 */ 424 425 int dquot_acquire(struct dquot *dquot) 426 { 427 int ret = 0, ret2 = 0; 428 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 429 430 mutex_lock(&dquot->dq_lock); 431 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { 432 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 433 if (ret < 0) 434 goto out_iolock; 435 } 436 /* Make sure flags update is visible after dquot has been filled */ 437 smp_mb__before_atomic(); 438 set_bit(DQ_READ_B, &dquot->dq_flags); 439 /* Instantiate dquot if needed */ 440 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 441 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 442 /* Write the info if needed */ 443 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 444 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 445 dquot->dq_sb, dquot->dq_id.type); 446 } 447 if (ret < 0) 448 goto out_iolock; 449 if (ret2 < 0) { 450 ret = ret2; 451 goto out_iolock; 452 } 453 } 454 /* 455 * Make sure flags update is visible after on-disk struct has been 456 * allocated. Paired with smp_rmb() in dqget(). 457 */ 458 smp_mb__before_atomic(); 459 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 460 out_iolock: 461 mutex_unlock(&dquot->dq_lock); 462 return ret; 463 } 464 EXPORT_SYMBOL(dquot_acquire); 465 466 /* 467 * Write dquot to disk 468 */ 469 int dquot_commit(struct dquot *dquot) 470 { 471 int ret = 0; 472 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 473 474 mutex_lock(&dquot->dq_lock); 475 if (!clear_dquot_dirty(dquot)) 476 goto out_lock; 477 /* Inactive dquot can be only if there was error during read/init 478 * => we have better not writing it */ 479 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 480 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 481 else 482 ret = -EIO; 483 out_lock: 484 mutex_unlock(&dquot->dq_lock); 485 return ret; 486 } 487 EXPORT_SYMBOL(dquot_commit); 488 489 /* 490 * Release dquot 491 */ 492 int dquot_release(struct dquot *dquot) 493 { 494 int ret = 0, ret2 = 0; 495 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 496 497 mutex_lock(&dquot->dq_lock); 498 /* Check whether we are not racing with some other dqget() */ 499 if (dquot_is_busy(dquot)) 500 goto out_dqlock; 501 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 502 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 503 /* Write the info */ 504 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 505 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 506 dquot->dq_sb, dquot->dq_id.type); 507 } 508 if (ret >= 0) 509 ret = ret2; 510 } 511 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 512 out_dqlock: 513 mutex_unlock(&dquot->dq_lock); 514 return ret; 515 } 516 EXPORT_SYMBOL(dquot_release); 517 518 void dquot_destroy(struct dquot *dquot) 519 { 520 kmem_cache_free(dquot_cachep, dquot); 521 } 522 EXPORT_SYMBOL(dquot_destroy); 523 524 static inline void do_destroy_dquot(struct dquot *dquot) 525 { 526 dquot->dq_sb->dq_op->destroy_dquot(dquot); 527 } 528 529 /* Invalidate all dquots on the list. Note that this function is called after 530 * quota is disabled and pointers from inodes removed so there cannot be new 531 * quota users. There can still be some users of quotas due to inodes being 532 * just deleted or pruned by prune_icache() (those are not attached to any 533 * list) or parallel quotactl call. We have to wait for such users. 534 */ 535 static void invalidate_dquots(struct super_block *sb, int type) 536 { 537 struct dquot *dquot, *tmp; 538 539 restart: 540 spin_lock(&dq_list_lock); 541 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 542 if (dquot->dq_sb != sb) 543 continue; 544 if (dquot->dq_id.type != type) 545 continue; 546 /* Wait for dquot users */ 547 if (atomic_read(&dquot->dq_count)) { 548 dqgrab(dquot); 549 spin_unlock(&dq_list_lock); 550 /* 551 * Once dqput() wakes us up, we know it's time to free 552 * the dquot. 553 * IMPORTANT: we rely on the fact that there is always 554 * at most one process waiting for dquot to free. 555 * Otherwise dq_count would be > 1 and we would never 556 * wake up. 557 */ 558 wait_event(dquot_ref_wq, 559 atomic_read(&dquot->dq_count) == 1); 560 dqput(dquot); 561 /* At this moment dquot() need not exist (it could be 562 * reclaimed by prune_dqcache(). Hence we must 563 * restart. */ 564 goto restart; 565 } 566 /* 567 * Quota now has no users and it has been written on last 568 * dqput() 569 */ 570 remove_dquot_hash(dquot); 571 remove_free_dquot(dquot); 572 remove_inuse(dquot); 573 do_destroy_dquot(dquot); 574 } 575 spin_unlock(&dq_list_lock); 576 } 577 578 /* Call callback for every active dquot on given filesystem */ 579 int dquot_scan_active(struct super_block *sb, 580 int (*fn)(struct dquot *dquot, unsigned long priv), 581 unsigned long priv) 582 { 583 struct dquot *dquot, *old_dquot = NULL; 584 int ret = 0; 585 586 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 587 588 spin_lock(&dq_list_lock); 589 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 590 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 591 continue; 592 if (dquot->dq_sb != sb) 593 continue; 594 /* Now we have active dquot so we can just increase use count */ 595 atomic_inc(&dquot->dq_count); 596 spin_unlock(&dq_list_lock); 597 dqput(old_dquot); 598 old_dquot = dquot; 599 /* 600 * ->release_dquot() can be racing with us. Our reference 601 * protects us from new calls to it so just wait for any 602 * outstanding call and recheck the DQ_ACTIVE_B after that. 603 */ 604 wait_on_dquot(dquot); 605 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 606 ret = fn(dquot, priv); 607 if (ret < 0) 608 goto out; 609 } 610 spin_lock(&dq_list_lock); 611 /* We are safe to continue now because our dquot could not 612 * be moved out of the inuse list while we hold the reference */ 613 } 614 spin_unlock(&dq_list_lock); 615 out: 616 dqput(old_dquot); 617 return ret; 618 } 619 EXPORT_SYMBOL(dquot_scan_active); 620 621 /* Write all dquot structures to quota files */ 622 int dquot_writeback_dquots(struct super_block *sb, int type) 623 { 624 struct list_head dirty; 625 struct dquot *dquot; 626 struct quota_info *dqopt = sb_dqopt(sb); 627 int cnt; 628 int err, ret = 0; 629 630 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 631 632 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 633 if (type != -1 && cnt != type) 634 continue; 635 if (!sb_has_quota_active(sb, cnt)) 636 continue; 637 spin_lock(&dq_list_lock); 638 /* Move list away to avoid livelock. */ 639 list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty); 640 while (!list_empty(&dirty)) { 641 dquot = list_first_entry(&dirty, struct dquot, 642 dq_dirty); 643 644 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 645 646 /* Now we have active dquot from which someone is 647 * holding reference so we can safely just increase 648 * use count */ 649 dqgrab(dquot); 650 spin_unlock(&dq_list_lock); 651 err = sb->dq_op->write_dquot(dquot); 652 if (err) { 653 /* 654 * Clear dirty bit anyway to avoid infinite 655 * loop here. 656 */ 657 clear_dquot_dirty(dquot); 658 if (!ret) 659 ret = err; 660 } 661 dqput(dquot); 662 spin_lock(&dq_list_lock); 663 } 664 spin_unlock(&dq_list_lock); 665 } 666 667 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 668 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 669 && info_dirty(&dqopt->info[cnt])) 670 sb->dq_op->write_info(sb, cnt); 671 dqstats_inc(DQST_SYNCS); 672 673 return ret; 674 } 675 EXPORT_SYMBOL(dquot_writeback_dquots); 676 677 /* Write all dquot structures to disk and make them visible from userspace */ 678 int dquot_quota_sync(struct super_block *sb, int type) 679 { 680 struct quota_info *dqopt = sb_dqopt(sb); 681 int cnt; 682 int ret; 683 684 ret = dquot_writeback_dquots(sb, type); 685 if (ret) 686 return ret; 687 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 688 return 0; 689 690 /* This is not very clever (and fast) but currently I don't know about 691 * any other simple way of getting quota data to disk and we must get 692 * them there for userspace to be visible... */ 693 if (sb->s_op->sync_fs) 694 sb->s_op->sync_fs(sb, 1); 695 sync_blockdev(sb->s_bdev); 696 697 /* 698 * Now when everything is written we can discard the pagecache so 699 * that userspace sees the changes. 700 */ 701 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 702 if (type != -1 && cnt != type) 703 continue; 704 if (!sb_has_quota_active(sb, cnt)) 705 continue; 706 inode_lock(dqopt->files[cnt]); 707 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 708 inode_unlock(dqopt->files[cnt]); 709 } 710 711 return 0; 712 } 713 EXPORT_SYMBOL(dquot_quota_sync); 714 715 static unsigned long 716 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 717 { 718 struct dquot *dquot; 719 unsigned long freed = 0; 720 721 spin_lock(&dq_list_lock); 722 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 723 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 724 remove_dquot_hash(dquot); 725 remove_free_dquot(dquot); 726 remove_inuse(dquot); 727 do_destroy_dquot(dquot); 728 sc->nr_to_scan--; 729 freed++; 730 } 731 spin_unlock(&dq_list_lock); 732 return freed; 733 } 734 735 static unsigned long 736 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 737 { 738 return vfs_pressure_ratio( 739 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 740 } 741 742 static struct shrinker dqcache_shrinker = { 743 .count_objects = dqcache_shrink_count, 744 .scan_objects = dqcache_shrink_scan, 745 .seeks = DEFAULT_SEEKS, 746 }; 747 748 /* 749 * Put reference to dquot 750 */ 751 void dqput(struct dquot *dquot) 752 { 753 int ret; 754 755 if (!dquot) 756 return; 757 #ifdef CONFIG_QUOTA_DEBUG 758 if (!atomic_read(&dquot->dq_count)) { 759 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 760 quotatypes[dquot->dq_id.type], 761 from_kqid(&init_user_ns, dquot->dq_id)); 762 BUG(); 763 } 764 #endif 765 dqstats_inc(DQST_DROPS); 766 we_slept: 767 spin_lock(&dq_list_lock); 768 if (atomic_read(&dquot->dq_count) > 1) { 769 /* We have more than one user... nothing to do */ 770 atomic_dec(&dquot->dq_count); 771 /* Releasing dquot during quotaoff phase? */ 772 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 773 atomic_read(&dquot->dq_count) == 1) 774 wake_up(&dquot_ref_wq); 775 spin_unlock(&dq_list_lock); 776 return; 777 } 778 /* Need to release dquot? */ 779 if (dquot_dirty(dquot)) { 780 spin_unlock(&dq_list_lock); 781 /* Commit dquot before releasing */ 782 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 783 if (ret < 0) { 784 quota_error(dquot->dq_sb, "Can't write quota structure" 785 " (error %d). Quota may get out of sync!", 786 ret); 787 /* 788 * We clear dirty bit anyway, so that we avoid 789 * infinite loop here 790 */ 791 clear_dquot_dirty(dquot); 792 } 793 goto we_slept; 794 } 795 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 796 spin_unlock(&dq_list_lock); 797 dquot->dq_sb->dq_op->release_dquot(dquot); 798 goto we_slept; 799 } 800 atomic_dec(&dquot->dq_count); 801 #ifdef CONFIG_QUOTA_DEBUG 802 /* sanity check */ 803 BUG_ON(!list_empty(&dquot->dq_free)); 804 #endif 805 put_dquot_last(dquot); 806 spin_unlock(&dq_list_lock); 807 } 808 EXPORT_SYMBOL(dqput); 809 810 struct dquot *dquot_alloc(struct super_block *sb, int type) 811 { 812 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 813 } 814 EXPORT_SYMBOL(dquot_alloc); 815 816 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 817 { 818 struct dquot *dquot; 819 820 dquot = sb->dq_op->alloc_dquot(sb, type); 821 if(!dquot) 822 return NULL; 823 824 mutex_init(&dquot->dq_lock); 825 INIT_LIST_HEAD(&dquot->dq_free); 826 INIT_LIST_HEAD(&dquot->dq_inuse); 827 INIT_HLIST_NODE(&dquot->dq_hash); 828 INIT_LIST_HEAD(&dquot->dq_dirty); 829 dquot->dq_sb = sb; 830 dquot->dq_id = make_kqid_invalid(type); 831 atomic_set(&dquot->dq_count, 1); 832 spin_lock_init(&dquot->dq_dqb_lock); 833 834 return dquot; 835 } 836 837 /* 838 * Get reference to dquot 839 * 840 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 841 * destroying our dquot by: 842 * a) checking for quota flags under dq_list_lock and 843 * b) getting a reference to dquot before we release dq_list_lock 844 */ 845 struct dquot *dqget(struct super_block *sb, struct kqid qid) 846 { 847 unsigned int hashent = hashfn(sb, qid); 848 struct dquot *dquot, *empty = NULL; 849 850 if (!qid_has_mapping(sb->s_user_ns, qid)) 851 return ERR_PTR(-EINVAL); 852 853 if (!sb_has_quota_active(sb, qid.type)) 854 return ERR_PTR(-ESRCH); 855 we_slept: 856 spin_lock(&dq_list_lock); 857 spin_lock(&dq_state_lock); 858 if (!sb_has_quota_active(sb, qid.type)) { 859 spin_unlock(&dq_state_lock); 860 spin_unlock(&dq_list_lock); 861 dquot = ERR_PTR(-ESRCH); 862 goto out; 863 } 864 spin_unlock(&dq_state_lock); 865 866 dquot = find_dquot(hashent, sb, qid); 867 if (!dquot) { 868 if (!empty) { 869 spin_unlock(&dq_list_lock); 870 empty = get_empty_dquot(sb, qid.type); 871 if (!empty) 872 schedule(); /* Try to wait for a moment... */ 873 goto we_slept; 874 } 875 dquot = empty; 876 empty = NULL; 877 dquot->dq_id = qid; 878 /* all dquots go on the inuse_list */ 879 put_inuse(dquot); 880 /* hash it first so it can be found */ 881 insert_dquot_hash(dquot); 882 spin_unlock(&dq_list_lock); 883 dqstats_inc(DQST_LOOKUPS); 884 } else { 885 if (!atomic_read(&dquot->dq_count)) 886 remove_free_dquot(dquot); 887 atomic_inc(&dquot->dq_count); 888 spin_unlock(&dq_list_lock); 889 dqstats_inc(DQST_CACHE_HITS); 890 dqstats_inc(DQST_LOOKUPS); 891 } 892 /* Wait for dq_lock - after this we know that either dquot_release() is 893 * already finished or it will be canceled due to dq_count > 1 test */ 894 wait_on_dquot(dquot); 895 /* Read the dquot / allocate space in quota file */ 896 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 897 int err; 898 899 err = sb->dq_op->acquire_dquot(dquot); 900 if (err < 0) { 901 dqput(dquot); 902 dquot = ERR_PTR(err); 903 goto out; 904 } 905 } 906 /* 907 * Make sure following reads see filled structure - paired with 908 * smp_mb__before_atomic() in dquot_acquire(). 909 */ 910 smp_rmb(); 911 #ifdef CONFIG_QUOTA_DEBUG 912 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 913 #endif 914 out: 915 if (empty) 916 do_destroy_dquot(empty); 917 918 return dquot; 919 } 920 EXPORT_SYMBOL(dqget); 921 922 static inline struct dquot **i_dquot(struct inode *inode) 923 { 924 return inode->i_sb->s_op->get_dquots(inode); 925 } 926 927 static int dqinit_needed(struct inode *inode, int type) 928 { 929 struct dquot * const *dquots; 930 int cnt; 931 932 if (IS_NOQUOTA(inode)) 933 return 0; 934 935 dquots = i_dquot(inode); 936 if (type != -1) 937 return !dquots[type]; 938 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 939 if (!dquots[cnt]) 940 return 1; 941 return 0; 942 } 943 944 /* This routine is guarded by s_umount semaphore */ 945 static int add_dquot_ref(struct super_block *sb, int type) 946 { 947 struct inode *inode, *old_inode = NULL; 948 #ifdef CONFIG_QUOTA_DEBUG 949 int reserved = 0; 950 #endif 951 int err = 0; 952 953 spin_lock(&sb->s_inode_list_lock); 954 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 955 spin_lock(&inode->i_lock); 956 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 957 !atomic_read(&inode->i_writecount) || 958 !dqinit_needed(inode, type)) { 959 spin_unlock(&inode->i_lock); 960 continue; 961 } 962 __iget(inode); 963 spin_unlock(&inode->i_lock); 964 spin_unlock(&sb->s_inode_list_lock); 965 966 #ifdef CONFIG_QUOTA_DEBUG 967 if (unlikely(inode_get_rsv_space(inode) > 0)) 968 reserved = 1; 969 #endif 970 iput(old_inode); 971 err = __dquot_initialize(inode, type); 972 if (err) { 973 iput(inode); 974 goto out; 975 } 976 977 /* 978 * We hold a reference to 'inode' so it couldn't have been 979 * removed from s_inodes list while we dropped the 980 * s_inode_list_lock. We cannot iput the inode now as we can be 981 * holding the last reference and we cannot iput it under 982 * s_inode_list_lock. So we keep the reference and iput it 983 * later. 984 */ 985 old_inode = inode; 986 cond_resched(); 987 spin_lock(&sb->s_inode_list_lock); 988 } 989 spin_unlock(&sb->s_inode_list_lock); 990 iput(old_inode); 991 out: 992 #ifdef CONFIG_QUOTA_DEBUG 993 if (reserved) { 994 quota_error(sb, "Writes happened before quota was turned on " 995 "thus quota information is probably inconsistent. " 996 "Please run quotacheck(8)"); 997 } 998 #endif 999 return err; 1000 } 1001 1002 /* 1003 * Remove references to dquots from inode and add dquot to list for freeing 1004 * if we have the last reference to dquot 1005 */ 1006 static void remove_inode_dquot_ref(struct inode *inode, int type, 1007 struct list_head *tofree_head) 1008 { 1009 struct dquot **dquots = i_dquot(inode); 1010 struct dquot *dquot = dquots[type]; 1011 1012 if (!dquot) 1013 return; 1014 1015 dquots[type] = NULL; 1016 if (list_empty(&dquot->dq_free)) { 1017 /* 1018 * The inode still has reference to dquot so it can't be in the 1019 * free list 1020 */ 1021 spin_lock(&dq_list_lock); 1022 list_add(&dquot->dq_free, tofree_head); 1023 spin_unlock(&dq_list_lock); 1024 } else { 1025 /* 1026 * Dquot is already in a list to put so we won't drop the last 1027 * reference here. 1028 */ 1029 dqput(dquot); 1030 } 1031 } 1032 1033 /* 1034 * Free list of dquots 1035 * Dquots are removed from inodes and no new references can be got so we are 1036 * the only ones holding reference 1037 */ 1038 static void put_dquot_list(struct list_head *tofree_head) 1039 { 1040 struct list_head *act_head; 1041 struct dquot *dquot; 1042 1043 act_head = tofree_head->next; 1044 while (act_head != tofree_head) { 1045 dquot = list_entry(act_head, struct dquot, dq_free); 1046 act_head = act_head->next; 1047 /* Remove dquot from the list so we won't have problems... */ 1048 list_del_init(&dquot->dq_free); 1049 dqput(dquot); 1050 } 1051 } 1052 1053 static void remove_dquot_ref(struct super_block *sb, int type, 1054 struct list_head *tofree_head) 1055 { 1056 struct inode *inode; 1057 #ifdef CONFIG_QUOTA_DEBUG 1058 int reserved = 0; 1059 #endif 1060 1061 spin_lock(&sb->s_inode_list_lock); 1062 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1063 /* 1064 * We have to scan also I_NEW inodes because they can already 1065 * have quota pointer initialized. Luckily, we need to touch 1066 * only quota pointers and these have separate locking 1067 * (dq_data_lock). 1068 */ 1069 spin_lock(&dq_data_lock); 1070 if (!IS_NOQUOTA(inode)) { 1071 #ifdef CONFIG_QUOTA_DEBUG 1072 if (unlikely(inode_get_rsv_space(inode) > 0)) 1073 reserved = 1; 1074 #endif 1075 remove_inode_dquot_ref(inode, type, tofree_head); 1076 } 1077 spin_unlock(&dq_data_lock); 1078 } 1079 spin_unlock(&sb->s_inode_list_lock); 1080 #ifdef CONFIG_QUOTA_DEBUG 1081 if (reserved) { 1082 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1083 " was disabled thus quota information is probably " 1084 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1085 } 1086 #endif 1087 } 1088 1089 /* Gather all references from inodes and drop them */ 1090 static void drop_dquot_ref(struct super_block *sb, int type) 1091 { 1092 LIST_HEAD(tofree_head); 1093 1094 if (sb->dq_op) { 1095 remove_dquot_ref(sb, type, &tofree_head); 1096 synchronize_srcu(&dquot_srcu); 1097 put_dquot_list(&tofree_head); 1098 } 1099 } 1100 1101 static inline 1102 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1103 { 1104 if (dquot->dq_dqb.dqb_rsvspace >= number) 1105 dquot->dq_dqb.dqb_rsvspace -= number; 1106 else { 1107 WARN_ON_ONCE(1); 1108 dquot->dq_dqb.dqb_rsvspace = 0; 1109 } 1110 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1111 dquot->dq_dqb.dqb_bsoftlimit) 1112 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1113 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1114 } 1115 1116 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1117 { 1118 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1119 dquot->dq_dqb.dqb_curinodes >= number) 1120 dquot->dq_dqb.dqb_curinodes -= number; 1121 else 1122 dquot->dq_dqb.dqb_curinodes = 0; 1123 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1124 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1125 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1126 } 1127 1128 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1129 { 1130 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1131 dquot->dq_dqb.dqb_curspace >= number) 1132 dquot->dq_dqb.dqb_curspace -= number; 1133 else 1134 dquot->dq_dqb.dqb_curspace = 0; 1135 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1136 dquot->dq_dqb.dqb_bsoftlimit) 1137 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1138 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1139 } 1140 1141 struct dquot_warn { 1142 struct super_block *w_sb; 1143 struct kqid w_dq_id; 1144 short w_type; 1145 }; 1146 1147 static int warning_issued(struct dquot *dquot, const int warntype) 1148 { 1149 int flag = (warntype == QUOTA_NL_BHARDWARN || 1150 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1151 ((warntype == QUOTA_NL_IHARDWARN || 1152 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1153 1154 if (!flag) 1155 return 0; 1156 return test_and_set_bit(flag, &dquot->dq_flags); 1157 } 1158 1159 #ifdef CONFIG_PRINT_QUOTA_WARNING 1160 static int flag_print_warnings = 1; 1161 1162 static int need_print_warning(struct dquot_warn *warn) 1163 { 1164 if (!flag_print_warnings) 1165 return 0; 1166 1167 switch (warn->w_dq_id.type) { 1168 case USRQUOTA: 1169 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1170 case GRPQUOTA: 1171 return in_group_p(warn->w_dq_id.gid); 1172 case PRJQUOTA: 1173 return 1; 1174 } 1175 return 0; 1176 } 1177 1178 /* Print warning to user which exceeded quota */ 1179 static void print_warning(struct dquot_warn *warn) 1180 { 1181 char *msg = NULL; 1182 struct tty_struct *tty; 1183 int warntype = warn->w_type; 1184 1185 if (warntype == QUOTA_NL_IHARDBELOW || 1186 warntype == QUOTA_NL_ISOFTBELOW || 1187 warntype == QUOTA_NL_BHARDBELOW || 1188 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1189 return; 1190 1191 tty = get_current_tty(); 1192 if (!tty) 1193 return; 1194 tty_write_message(tty, warn->w_sb->s_id); 1195 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1196 tty_write_message(tty, ": warning, "); 1197 else 1198 tty_write_message(tty, ": write failed, "); 1199 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1200 switch (warntype) { 1201 case QUOTA_NL_IHARDWARN: 1202 msg = " file limit reached.\r\n"; 1203 break; 1204 case QUOTA_NL_ISOFTLONGWARN: 1205 msg = " file quota exceeded too long.\r\n"; 1206 break; 1207 case QUOTA_NL_ISOFTWARN: 1208 msg = " file quota exceeded.\r\n"; 1209 break; 1210 case QUOTA_NL_BHARDWARN: 1211 msg = " block limit reached.\r\n"; 1212 break; 1213 case QUOTA_NL_BSOFTLONGWARN: 1214 msg = " block quota exceeded too long.\r\n"; 1215 break; 1216 case QUOTA_NL_BSOFTWARN: 1217 msg = " block quota exceeded.\r\n"; 1218 break; 1219 } 1220 tty_write_message(tty, msg); 1221 tty_kref_put(tty); 1222 } 1223 #endif 1224 1225 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1226 int warntype) 1227 { 1228 if (warning_issued(dquot, warntype)) 1229 return; 1230 warn->w_type = warntype; 1231 warn->w_sb = dquot->dq_sb; 1232 warn->w_dq_id = dquot->dq_id; 1233 } 1234 1235 /* 1236 * Write warnings to the console and send warning messages over netlink. 1237 * 1238 * Note that this function can call into tty and networking code. 1239 */ 1240 static void flush_warnings(struct dquot_warn *warn) 1241 { 1242 int i; 1243 1244 for (i = 0; i < MAXQUOTAS; i++) { 1245 if (warn[i].w_type == QUOTA_NL_NOWARN) 1246 continue; 1247 #ifdef CONFIG_PRINT_QUOTA_WARNING 1248 print_warning(&warn[i]); 1249 #endif 1250 quota_send_warning(warn[i].w_dq_id, 1251 warn[i].w_sb->s_dev, warn[i].w_type); 1252 } 1253 } 1254 1255 static int ignore_hardlimit(struct dquot *dquot) 1256 { 1257 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1258 1259 return capable(CAP_SYS_RESOURCE) && 1260 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1261 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1262 } 1263 1264 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1265 struct dquot_warn *warn) 1266 { 1267 qsize_t newinodes; 1268 int ret = 0; 1269 1270 spin_lock(&dquot->dq_dqb_lock); 1271 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1272 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1273 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1274 goto add; 1275 1276 if (dquot->dq_dqb.dqb_ihardlimit && 1277 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1278 !ignore_hardlimit(dquot)) { 1279 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1280 ret = -EDQUOT; 1281 goto out; 1282 } 1283 1284 if (dquot->dq_dqb.dqb_isoftlimit && 1285 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1286 dquot->dq_dqb.dqb_itime && 1287 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1288 !ignore_hardlimit(dquot)) { 1289 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1290 ret = -EDQUOT; 1291 goto out; 1292 } 1293 1294 if (dquot->dq_dqb.dqb_isoftlimit && 1295 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1296 dquot->dq_dqb.dqb_itime == 0) { 1297 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1298 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1299 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1300 } 1301 add: 1302 dquot->dq_dqb.dqb_curinodes = newinodes; 1303 1304 out: 1305 spin_unlock(&dquot->dq_dqb_lock); 1306 return ret; 1307 } 1308 1309 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1310 qsize_t rsv_space, unsigned int flags, 1311 struct dquot_warn *warn) 1312 { 1313 qsize_t tspace; 1314 struct super_block *sb = dquot->dq_sb; 1315 int ret = 0; 1316 1317 spin_lock(&dquot->dq_dqb_lock); 1318 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1319 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1320 goto finish; 1321 1322 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1323 + space + rsv_space; 1324 1325 if (dquot->dq_dqb.dqb_bhardlimit && 1326 tspace > dquot->dq_dqb.dqb_bhardlimit && 1327 !ignore_hardlimit(dquot)) { 1328 if (flags & DQUOT_SPACE_WARN) 1329 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1330 ret = -EDQUOT; 1331 goto finish; 1332 } 1333 1334 if (dquot->dq_dqb.dqb_bsoftlimit && 1335 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1336 dquot->dq_dqb.dqb_btime && 1337 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1338 !ignore_hardlimit(dquot)) { 1339 if (flags & DQUOT_SPACE_WARN) 1340 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1341 ret = -EDQUOT; 1342 goto finish; 1343 } 1344 1345 if (dquot->dq_dqb.dqb_bsoftlimit && 1346 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1347 dquot->dq_dqb.dqb_btime == 0) { 1348 if (flags & DQUOT_SPACE_WARN) { 1349 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1350 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1351 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1352 } else { 1353 /* 1354 * We don't allow preallocation to exceed softlimit so exceeding will 1355 * be always printed 1356 */ 1357 ret = -EDQUOT; 1358 goto finish; 1359 } 1360 } 1361 finish: 1362 /* 1363 * We have to be careful and go through warning generation & grace time 1364 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1365 * only here... 1366 */ 1367 if (flags & DQUOT_SPACE_NOFAIL) 1368 ret = 0; 1369 if (!ret) { 1370 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1371 dquot->dq_dqb.dqb_curspace += space; 1372 } 1373 spin_unlock(&dquot->dq_dqb_lock); 1374 return ret; 1375 } 1376 1377 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1378 { 1379 qsize_t newinodes; 1380 1381 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1382 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1383 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1384 return QUOTA_NL_NOWARN; 1385 1386 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1387 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1388 return QUOTA_NL_ISOFTBELOW; 1389 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1390 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1391 return QUOTA_NL_IHARDBELOW; 1392 return QUOTA_NL_NOWARN; 1393 } 1394 1395 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1396 { 1397 qsize_t tspace; 1398 1399 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1400 1401 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1402 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1403 return QUOTA_NL_NOWARN; 1404 1405 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1406 return QUOTA_NL_BSOFTBELOW; 1407 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1408 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1409 return QUOTA_NL_BHARDBELOW; 1410 return QUOTA_NL_NOWARN; 1411 } 1412 1413 static int dquot_active(const struct inode *inode) 1414 { 1415 struct super_block *sb = inode->i_sb; 1416 1417 if (IS_NOQUOTA(inode)) 1418 return 0; 1419 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1420 } 1421 1422 /* 1423 * Initialize quota pointers in inode 1424 * 1425 * It is better to call this function outside of any transaction as it 1426 * might need a lot of space in journal for dquot structure allocation. 1427 */ 1428 static int __dquot_initialize(struct inode *inode, int type) 1429 { 1430 int cnt, init_needed = 0; 1431 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1432 struct super_block *sb = inode->i_sb; 1433 qsize_t rsv; 1434 int ret = 0; 1435 1436 if (!dquot_active(inode)) 1437 return 0; 1438 1439 dquots = i_dquot(inode); 1440 1441 /* First get references to structures we might need. */ 1442 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1443 struct kqid qid; 1444 kprojid_t projid; 1445 int rc; 1446 struct dquot *dquot; 1447 1448 if (type != -1 && cnt != type) 1449 continue; 1450 /* 1451 * The i_dquot should have been initialized in most cases, 1452 * we check it without locking here to avoid unnecessary 1453 * dqget()/dqput() calls. 1454 */ 1455 if (dquots[cnt]) 1456 continue; 1457 1458 if (!sb_has_quota_active(sb, cnt)) 1459 continue; 1460 1461 init_needed = 1; 1462 1463 switch (cnt) { 1464 case USRQUOTA: 1465 qid = make_kqid_uid(inode->i_uid); 1466 break; 1467 case GRPQUOTA: 1468 qid = make_kqid_gid(inode->i_gid); 1469 break; 1470 case PRJQUOTA: 1471 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1472 if (rc) 1473 continue; 1474 qid = make_kqid_projid(projid); 1475 break; 1476 } 1477 dquot = dqget(sb, qid); 1478 if (IS_ERR(dquot)) { 1479 /* We raced with somebody turning quotas off... */ 1480 if (PTR_ERR(dquot) != -ESRCH) { 1481 ret = PTR_ERR(dquot); 1482 goto out_put; 1483 } 1484 dquot = NULL; 1485 } 1486 got[cnt] = dquot; 1487 } 1488 1489 /* All required i_dquot has been initialized */ 1490 if (!init_needed) 1491 return 0; 1492 1493 spin_lock(&dq_data_lock); 1494 if (IS_NOQUOTA(inode)) 1495 goto out_lock; 1496 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1497 if (type != -1 && cnt != type) 1498 continue; 1499 /* Avoid races with quotaoff() */ 1500 if (!sb_has_quota_active(sb, cnt)) 1501 continue; 1502 /* We could race with quotaon or dqget() could have failed */ 1503 if (!got[cnt]) 1504 continue; 1505 if (!dquots[cnt]) { 1506 dquots[cnt] = got[cnt]; 1507 got[cnt] = NULL; 1508 /* 1509 * Make quota reservation system happy if someone 1510 * did a write before quota was turned on 1511 */ 1512 rsv = inode_get_rsv_space(inode); 1513 if (unlikely(rsv)) { 1514 spin_lock(&inode->i_lock); 1515 /* Get reservation again under proper lock */ 1516 rsv = __inode_get_rsv_space(inode); 1517 spin_lock(&dquots[cnt]->dq_dqb_lock); 1518 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1519 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1520 spin_unlock(&inode->i_lock); 1521 } 1522 } 1523 } 1524 out_lock: 1525 spin_unlock(&dq_data_lock); 1526 out_put: 1527 /* Drop unused references */ 1528 dqput_all(got); 1529 1530 return ret; 1531 } 1532 1533 int dquot_initialize(struct inode *inode) 1534 { 1535 return __dquot_initialize(inode, -1); 1536 } 1537 EXPORT_SYMBOL(dquot_initialize); 1538 1539 bool dquot_initialize_needed(struct inode *inode) 1540 { 1541 struct dquot **dquots; 1542 int i; 1543 1544 if (!dquot_active(inode)) 1545 return false; 1546 1547 dquots = i_dquot(inode); 1548 for (i = 0; i < MAXQUOTAS; i++) 1549 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1550 return true; 1551 return false; 1552 } 1553 EXPORT_SYMBOL(dquot_initialize_needed); 1554 1555 /* 1556 * Release all quotas referenced by inode. 1557 * 1558 * This function only be called on inode free or converting 1559 * a file to quota file, no other users for the i_dquot in 1560 * both cases, so we needn't call synchronize_srcu() after 1561 * clearing i_dquot. 1562 */ 1563 static void __dquot_drop(struct inode *inode) 1564 { 1565 int cnt; 1566 struct dquot **dquots = i_dquot(inode); 1567 struct dquot *put[MAXQUOTAS]; 1568 1569 spin_lock(&dq_data_lock); 1570 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1571 put[cnt] = dquots[cnt]; 1572 dquots[cnt] = NULL; 1573 } 1574 spin_unlock(&dq_data_lock); 1575 dqput_all(put); 1576 } 1577 1578 void dquot_drop(struct inode *inode) 1579 { 1580 struct dquot * const *dquots; 1581 int cnt; 1582 1583 if (IS_NOQUOTA(inode)) 1584 return; 1585 1586 /* 1587 * Test before calling to rule out calls from proc and such 1588 * where we are not allowed to block. Note that this is 1589 * actually reliable test even without the lock - the caller 1590 * must assure that nobody can come after the DQUOT_DROP and 1591 * add quota pointers back anyway. 1592 */ 1593 dquots = i_dquot(inode); 1594 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1595 if (dquots[cnt]) 1596 break; 1597 } 1598 1599 if (cnt < MAXQUOTAS) 1600 __dquot_drop(inode); 1601 } 1602 EXPORT_SYMBOL(dquot_drop); 1603 1604 /* 1605 * inode_reserved_space is managed internally by quota, and protected by 1606 * i_lock similar to i_blocks+i_bytes. 1607 */ 1608 static qsize_t *inode_reserved_space(struct inode * inode) 1609 { 1610 /* Filesystem must explicitly define it's own method in order to use 1611 * quota reservation interface */ 1612 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1613 return inode->i_sb->dq_op->get_reserved_space(inode); 1614 } 1615 1616 static qsize_t __inode_get_rsv_space(struct inode *inode) 1617 { 1618 if (!inode->i_sb->dq_op->get_reserved_space) 1619 return 0; 1620 return *inode_reserved_space(inode); 1621 } 1622 1623 static qsize_t inode_get_rsv_space(struct inode *inode) 1624 { 1625 qsize_t ret; 1626 1627 if (!inode->i_sb->dq_op->get_reserved_space) 1628 return 0; 1629 spin_lock(&inode->i_lock); 1630 ret = __inode_get_rsv_space(inode); 1631 spin_unlock(&inode->i_lock); 1632 return ret; 1633 } 1634 1635 /* 1636 * This functions updates i_blocks+i_bytes fields and quota information 1637 * (together with appropriate checks). 1638 * 1639 * NOTE: We absolutely rely on the fact that caller dirties the inode 1640 * (usually helpers in quotaops.h care about this) and holds a handle for 1641 * the current transaction so that dquot write and inode write go into the 1642 * same transaction. 1643 */ 1644 1645 /* 1646 * This operation can block, but only after everything is updated 1647 */ 1648 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1649 { 1650 int cnt, ret = 0, index; 1651 struct dquot_warn warn[MAXQUOTAS]; 1652 int reserve = flags & DQUOT_SPACE_RESERVE; 1653 struct dquot **dquots; 1654 1655 if (!dquot_active(inode)) { 1656 if (reserve) { 1657 spin_lock(&inode->i_lock); 1658 *inode_reserved_space(inode) += number; 1659 spin_unlock(&inode->i_lock); 1660 } else { 1661 inode_add_bytes(inode, number); 1662 } 1663 goto out; 1664 } 1665 1666 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1667 warn[cnt].w_type = QUOTA_NL_NOWARN; 1668 1669 dquots = i_dquot(inode); 1670 index = srcu_read_lock(&dquot_srcu); 1671 spin_lock(&inode->i_lock); 1672 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1673 if (!dquots[cnt]) 1674 continue; 1675 if (reserve) { 1676 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1677 &warn[cnt]); 1678 } else { 1679 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1680 &warn[cnt]); 1681 } 1682 if (ret) { 1683 /* Back out changes we already did */ 1684 for (cnt--; cnt >= 0; cnt--) { 1685 if (!dquots[cnt]) 1686 continue; 1687 spin_lock(&dquots[cnt]->dq_dqb_lock); 1688 if (reserve) 1689 dquot_free_reserved_space(dquots[cnt], 1690 number); 1691 else 1692 dquot_decr_space(dquots[cnt], number); 1693 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1694 } 1695 spin_unlock(&inode->i_lock); 1696 goto out_flush_warn; 1697 } 1698 } 1699 if (reserve) 1700 *inode_reserved_space(inode) += number; 1701 else 1702 __inode_add_bytes(inode, number); 1703 spin_unlock(&inode->i_lock); 1704 1705 if (reserve) 1706 goto out_flush_warn; 1707 mark_all_dquot_dirty(dquots); 1708 out_flush_warn: 1709 srcu_read_unlock(&dquot_srcu, index); 1710 flush_warnings(warn); 1711 out: 1712 return ret; 1713 } 1714 EXPORT_SYMBOL(__dquot_alloc_space); 1715 1716 /* 1717 * This operation can block, but only after everything is updated 1718 */ 1719 int dquot_alloc_inode(struct inode *inode) 1720 { 1721 int cnt, ret = 0, index; 1722 struct dquot_warn warn[MAXQUOTAS]; 1723 struct dquot * const *dquots; 1724 1725 if (!dquot_active(inode)) 1726 return 0; 1727 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1728 warn[cnt].w_type = QUOTA_NL_NOWARN; 1729 1730 dquots = i_dquot(inode); 1731 index = srcu_read_lock(&dquot_srcu); 1732 spin_lock(&inode->i_lock); 1733 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1734 if (!dquots[cnt]) 1735 continue; 1736 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1737 if (ret) { 1738 for (cnt--; cnt >= 0; cnt--) { 1739 if (!dquots[cnt]) 1740 continue; 1741 /* Back out changes we already did */ 1742 spin_lock(&dquots[cnt]->dq_dqb_lock); 1743 dquot_decr_inodes(dquots[cnt], 1); 1744 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1745 } 1746 goto warn_put_all; 1747 } 1748 } 1749 1750 warn_put_all: 1751 spin_unlock(&inode->i_lock); 1752 if (ret == 0) 1753 mark_all_dquot_dirty(dquots); 1754 srcu_read_unlock(&dquot_srcu, index); 1755 flush_warnings(warn); 1756 return ret; 1757 } 1758 EXPORT_SYMBOL(dquot_alloc_inode); 1759 1760 /* 1761 * Convert in-memory reserved quotas to real consumed quotas 1762 */ 1763 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1764 { 1765 struct dquot **dquots; 1766 int cnt, index; 1767 1768 if (!dquot_active(inode)) { 1769 spin_lock(&inode->i_lock); 1770 *inode_reserved_space(inode) -= number; 1771 __inode_add_bytes(inode, number); 1772 spin_unlock(&inode->i_lock); 1773 return 0; 1774 } 1775 1776 dquots = i_dquot(inode); 1777 index = srcu_read_lock(&dquot_srcu); 1778 spin_lock(&inode->i_lock); 1779 /* Claim reserved quotas to allocated quotas */ 1780 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1781 if (dquots[cnt]) { 1782 struct dquot *dquot = dquots[cnt]; 1783 1784 spin_lock(&dquot->dq_dqb_lock); 1785 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1786 number = dquot->dq_dqb.dqb_rsvspace; 1787 dquot->dq_dqb.dqb_curspace += number; 1788 dquot->dq_dqb.dqb_rsvspace -= number; 1789 spin_unlock(&dquot->dq_dqb_lock); 1790 } 1791 } 1792 /* Update inode bytes */ 1793 *inode_reserved_space(inode) -= number; 1794 __inode_add_bytes(inode, number); 1795 spin_unlock(&inode->i_lock); 1796 mark_all_dquot_dirty(dquots); 1797 srcu_read_unlock(&dquot_srcu, index); 1798 return 0; 1799 } 1800 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1801 1802 /* 1803 * Convert allocated space back to in-memory reserved quotas 1804 */ 1805 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1806 { 1807 struct dquot **dquots; 1808 int cnt, index; 1809 1810 if (!dquot_active(inode)) { 1811 spin_lock(&inode->i_lock); 1812 *inode_reserved_space(inode) += number; 1813 __inode_sub_bytes(inode, number); 1814 spin_unlock(&inode->i_lock); 1815 return; 1816 } 1817 1818 dquots = i_dquot(inode); 1819 index = srcu_read_lock(&dquot_srcu); 1820 spin_lock(&inode->i_lock); 1821 /* Claim reserved quotas to allocated quotas */ 1822 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1823 if (dquots[cnt]) { 1824 struct dquot *dquot = dquots[cnt]; 1825 1826 spin_lock(&dquot->dq_dqb_lock); 1827 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1828 number = dquot->dq_dqb.dqb_curspace; 1829 dquot->dq_dqb.dqb_rsvspace += number; 1830 dquot->dq_dqb.dqb_curspace -= number; 1831 spin_unlock(&dquot->dq_dqb_lock); 1832 } 1833 } 1834 /* Update inode bytes */ 1835 *inode_reserved_space(inode) += number; 1836 __inode_sub_bytes(inode, number); 1837 spin_unlock(&inode->i_lock); 1838 mark_all_dquot_dirty(dquots); 1839 srcu_read_unlock(&dquot_srcu, index); 1840 return; 1841 } 1842 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1843 1844 /* 1845 * This operation can block, but only after everything is updated 1846 */ 1847 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1848 { 1849 unsigned int cnt; 1850 struct dquot_warn warn[MAXQUOTAS]; 1851 struct dquot **dquots; 1852 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1853 1854 if (!dquot_active(inode)) { 1855 if (reserve) { 1856 spin_lock(&inode->i_lock); 1857 *inode_reserved_space(inode) -= number; 1858 spin_unlock(&inode->i_lock); 1859 } else { 1860 inode_sub_bytes(inode, number); 1861 } 1862 return; 1863 } 1864 1865 dquots = i_dquot(inode); 1866 index = srcu_read_lock(&dquot_srcu); 1867 spin_lock(&inode->i_lock); 1868 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1869 int wtype; 1870 1871 warn[cnt].w_type = QUOTA_NL_NOWARN; 1872 if (!dquots[cnt]) 1873 continue; 1874 spin_lock(&dquots[cnt]->dq_dqb_lock); 1875 wtype = info_bdq_free(dquots[cnt], number); 1876 if (wtype != QUOTA_NL_NOWARN) 1877 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1878 if (reserve) 1879 dquot_free_reserved_space(dquots[cnt], number); 1880 else 1881 dquot_decr_space(dquots[cnt], number); 1882 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1883 } 1884 if (reserve) 1885 *inode_reserved_space(inode) -= number; 1886 else 1887 __inode_sub_bytes(inode, number); 1888 spin_unlock(&inode->i_lock); 1889 1890 if (reserve) 1891 goto out_unlock; 1892 mark_all_dquot_dirty(dquots); 1893 out_unlock: 1894 srcu_read_unlock(&dquot_srcu, index); 1895 flush_warnings(warn); 1896 } 1897 EXPORT_SYMBOL(__dquot_free_space); 1898 1899 /* 1900 * This operation can block, but only after everything is updated 1901 */ 1902 void dquot_free_inode(struct inode *inode) 1903 { 1904 unsigned int cnt; 1905 struct dquot_warn warn[MAXQUOTAS]; 1906 struct dquot * const *dquots; 1907 int index; 1908 1909 if (!dquot_active(inode)) 1910 return; 1911 1912 dquots = i_dquot(inode); 1913 index = srcu_read_lock(&dquot_srcu); 1914 spin_lock(&inode->i_lock); 1915 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1916 int wtype; 1917 1918 warn[cnt].w_type = QUOTA_NL_NOWARN; 1919 if (!dquots[cnt]) 1920 continue; 1921 spin_lock(&dquots[cnt]->dq_dqb_lock); 1922 wtype = info_idq_free(dquots[cnt], 1); 1923 if (wtype != QUOTA_NL_NOWARN) 1924 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1925 dquot_decr_inodes(dquots[cnt], 1); 1926 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1927 } 1928 spin_unlock(&inode->i_lock); 1929 mark_all_dquot_dirty(dquots); 1930 srcu_read_unlock(&dquot_srcu, index); 1931 flush_warnings(warn); 1932 } 1933 EXPORT_SYMBOL(dquot_free_inode); 1934 1935 /* 1936 * Transfer the number of inode and blocks from one diskquota to an other. 1937 * On success, dquot references in transfer_to are consumed and references 1938 * to original dquots that need to be released are placed there. On failure, 1939 * references are kept untouched. 1940 * 1941 * This operation can block, but only after everything is updated 1942 * A transaction must be started when entering this function. 1943 * 1944 * We are holding reference on transfer_from & transfer_to, no need to 1945 * protect them by srcu_read_lock(). 1946 */ 1947 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1948 { 1949 qsize_t cur_space; 1950 qsize_t rsv_space = 0; 1951 qsize_t inode_usage = 1; 1952 struct dquot *transfer_from[MAXQUOTAS] = {}; 1953 int cnt, ret = 0; 1954 char is_valid[MAXQUOTAS] = {}; 1955 struct dquot_warn warn_to[MAXQUOTAS]; 1956 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1957 struct dquot_warn warn_from_space[MAXQUOTAS]; 1958 1959 if (IS_NOQUOTA(inode)) 1960 return 0; 1961 1962 if (inode->i_sb->dq_op->get_inode_usage) { 1963 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1964 if (ret) 1965 return ret; 1966 } 1967 1968 /* Initialize the arrays */ 1969 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1970 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1971 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1972 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1973 } 1974 1975 spin_lock(&dq_data_lock); 1976 spin_lock(&inode->i_lock); 1977 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1978 spin_unlock(&inode->i_lock); 1979 spin_unlock(&dq_data_lock); 1980 return 0; 1981 } 1982 cur_space = __inode_get_bytes(inode); 1983 rsv_space = __inode_get_rsv_space(inode); 1984 /* 1985 * Build the transfer_from list, check limits, and update usage in 1986 * the target structures. 1987 */ 1988 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1989 /* 1990 * Skip changes for same uid or gid or for turned off quota-type. 1991 */ 1992 if (!transfer_to[cnt]) 1993 continue; 1994 /* Avoid races with quotaoff() */ 1995 if (!sb_has_quota_active(inode->i_sb, cnt)) 1996 continue; 1997 is_valid[cnt] = 1; 1998 transfer_from[cnt] = i_dquot(inode)[cnt]; 1999 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 2000 &warn_to[cnt]); 2001 if (ret) 2002 goto over_quota; 2003 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 2004 DQUOT_SPACE_WARN, &warn_to[cnt]); 2005 if (ret) { 2006 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2007 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2008 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2009 goto over_quota; 2010 } 2011 } 2012 2013 /* Decrease usage for source structures and update quota pointers */ 2014 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2015 if (!is_valid[cnt]) 2016 continue; 2017 /* Due to IO error we might not have transfer_from[] structure */ 2018 if (transfer_from[cnt]) { 2019 int wtype; 2020 2021 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2022 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2023 if (wtype != QUOTA_NL_NOWARN) 2024 prepare_warning(&warn_from_inodes[cnt], 2025 transfer_from[cnt], wtype); 2026 wtype = info_bdq_free(transfer_from[cnt], 2027 cur_space + rsv_space); 2028 if (wtype != QUOTA_NL_NOWARN) 2029 prepare_warning(&warn_from_space[cnt], 2030 transfer_from[cnt], wtype); 2031 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2032 dquot_decr_space(transfer_from[cnt], cur_space); 2033 dquot_free_reserved_space(transfer_from[cnt], 2034 rsv_space); 2035 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2036 } 2037 i_dquot(inode)[cnt] = transfer_to[cnt]; 2038 } 2039 spin_unlock(&inode->i_lock); 2040 spin_unlock(&dq_data_lock); 2041 2042 mark_all_dquot_dirty(transfer_from); 2043 mark_all_dquot_dirty(transfer_to); 2044 flush_warnings(warn_to); 2045 flush_warnings(warn_from_inodes); 2046 flush_warnings(warn_from_space); 2047 /* Pass back references to put */ 2048 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2049 if (is_valid[cnt]) 2050 transfer_to[cnt] = transfer_from[cnt]; 2051 return 0; 2052 over_quota: 2053 /* Back out changes we already did */ 2054 for (cnt--; cnt >= 0; cnt--) { 2055 if (!is_valid[cnt]) 2056 continue; 2057 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2058 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2059 dquot_decr_space(transfer_to[cnt], cur_space); 2060 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2061 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2062 } 2063 spin_unlock(&inode->i_lock); 2064 spin_unlock(&dq_data_lock); 2065 flush_warnings(warn_to); 2066 return ret; 2067 } 2068 EXPORT_SYMBOL(__dquot_transfer); 2069 2070 /* Wrapper for transferring ownership of an inode for uid/gid only 2071 * Called from FSXXX_setattr() 2072 */ 2073 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2074 { 2075 struct dquot *transfer_to[MAXQUOTAS] = {}; 2076 struct dquot *dquot; 2077 struct super_block *sb = inode->i_sb; 2078 int ret; 2079 2080 if (!dquot_active(inode)) 2081 return 0; 2082 2083 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2084 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2085 if (IS_ERR(dquot)) { 2086 if (PTR_ERR(dquot) != -ESRCH) { 2087 ret = PTR_ERR(dquot); 2088 goto out_put; 2089 } 2090 dquot = NULL; 2091 } 2092 transfer_to[USRQUOTA] = dquot; 2093 } 2094 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2095 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2096 if (IS_ERR(dquot)) { 2097 if (PTR_ERR(dquot) != -ESRCH) { 2098 ret = PTR_ERR(dquot); 2099 goto out_put; 2100 } 2101 dquot = NULL; 2102 } 2103 transfer_to[GRPQUOTA] = dquot; 2104 } 2105 ret = __dquot_transfer(inode, transfer_to); 2106 out_put: 2107 dqput_all(transfer_to); 2108 return ret; 2109 } 2110 EXPORT_SYMBOL(dquot_transfer); 2111 2112 /* 2113 * Write info of quota file to disk 2114 */ 2115 int dquot_commit_info(struct super_block *sb, int type) 2116 { 2117 struct quota_info *dqopt = sb_dqopt(sb); 2118 2119 return dqopt->ops[type]->write_file_info(sb, type); 2120 } 2121 EXPORT_SYMBOL(dquot_commit_info); 2122 2123 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2124 { 2125 struct quota_info *dqopt = sb_dqopt(sb); 2126 2127 if (!sb_has_quota_active(sb, qid->type)) 2128 return -ESRCH; 2129 if (!dqopt->ops[qid->type]->get_next_id) 2130 return -ENOSYS; 2131 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2132 } 2133 EXPORT_SYMBOL(dquot_get_next_id); 2134 2135 /* 2136 * Definitions of diskquota operations. 2137 */ 2138 const struct dquot_operations dquot_operations = { 2139 .write_dquot = dquot_commit, 2140 .acquire_dquot = dquot_acquire, 2141 .release_dquot = dquot_release, 2142 .mark_dirty = dquot_mark_dquot_dirty, 2143 .write_info = dquot_commit_info, 2144 .alloc_dquot = dquot_alloc, 2145 .destroy_dquot = dquot_destroy, 2146 .get_next_id = dquot_get_next_id, 2147 }; 2148 EXPORT_SYMBOL(dquot_operations); 2149 2150 /* 2151 * Generic helper for ->open on filesystems supporting disk quotas. 2152 */ 2153 int dquot_file_open(struct inode *inode, struct file *file) 2154 { 2155 int error; 2156 2157 error = generic_file_open(inode, file); 2158 if (!error && (file->f_mode & FMODE_WRITE)) 2159 error = dquot_initialize(inode); 2160 return error; 2161 } 2162 EXPORT_SYMBOL(dquot_file_open); 2163 2164 static void vfs_cleanup_quota_inode(struct super_block *sb, int type) 2165 { 2166 struct quota_info *dqopt = sb_dqopt(sb); 2167 struct inode *inode = dqopt->files[type]; 2168 2169 if (!inode) 2170 return; 2171 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2172 inode_lock(inode); 2173 inode->i_flags &= ~S_NOQUOTA; 2174 inode_unlock(inode); 2175 } 2176 dqopt->files[type] = NULL; 2177 iput(inode); 2178 } 2179 2180 /* 2181 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2182 */ 2183 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2184 { 2185 int cnt; 2186 struct quota_info *dqopt = sb_dqopt(sb); 2187 2188 /* s_umount should be held in exclusive mode */ 2189 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2190 up_read(&sb->s_umount); 2191 2192 /* Cannot turn off usage accounting without turning off limits, or 2193 * suspend quotas and simultaneously turn quotas off. */ 2194 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2195 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2196 DQUOT_USAGE_ENABLED))) 2197 return -EINVAL; 2198 2199 /* 2200 * Skip everything if there's nothing to do. We have to do this because 2201 * sometimes we are called when fill_super() failed and calling 2202 * sync_fs() in such cases does no good. 2203 */ 2204 if (!sb_any_quota_loaded(sb)) 2205 return 0; 2206 2207 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2208 if (type != -1 && cnt != type) 2209 continue; 2210 if (!sb_has_quota_loaded(sb, cnt)) 2211 continue; 2212 2213 if (flags & DQUOT_SUSPENDED) { 2214 spin_lock(&dq_state_lock); 2215 dqopt->flags |= 2216 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2217 spin_unlock(&dq_state_lock); 2218 } else { 2219 spin_lock(&dq_state_lock); 2220 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2221 /* Turning off suspended quotas? */ 2222 if (!sb_has_quota_loaded(sb, cnt) && 2223 sb_has_quota_suspended(sb, cnt)) { 2224 dqopt->flags &= ~dquot_state_flag( 2225 DQUOT_SUSPENDED, cnt); 2226 spin_unlock(&dq_state_lock); 2227 vfs_cleanup_quota_inode(sb, cnt); 2228 continue; 2229 } 2230 spin_unlock(&dq_state_lock); 2231 } 2232 2233 /* We still have to keep quota loaded? */ 2234 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2235 continue; 2236 2237 /* Note: these are blocking operations */ 2238 drop_dquot_ref(sb, cnt); 2239 invalidate_dquots(sb, cnt); 2240 /* 2241 * Now all dquots should be invalidated, all writes done so we 2242 * should be only users of the info. No locks needed. 2243 */ 2244 if (info_dirty(&dqopt->info[cnt])) 2245 sb->dq_op->write_info(sb, cnt); 2246 if (dqopt->ops[cnt]->free_file_info) 2247 dqopt->ops[cnt]->free_file_info(sb, cnt); 2248 put_quota_format(dqopt->info[cnt].dqi_format); 2249 dqopt->info[cnt].dqi_flags = 0; 2250 dqopt->info[cnt].dqi_igrace = 0; 2251 dqopt->info[cnt].dqi_bgrace = 0; 2252 dqopt->ops[cnt] = NULL; 2253 } 2254 2255 /* Skip syncing and setting flags if quota files are hidden */ 2256 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2257 goto put_inodes; 2258 2259 /* Sync the superblock so that buffers with quota data are written to 2260 * disk (and so userspace sees correct data afterwards). */ 2261 if (sb->s_op->sync_fs) 2262 sb->s_op->sync_fs(sb, 1); 2263 sync_blockdev(sb->s_bdev); 2264 /* Now the quota files are just ordinary files and we can set the 2265 * inode flags back. Moreover we discard the pagecache so that 2266 * userspace sees the writes we did bypassing the pagecache. We 2267 * must also discard the blockdev buffers so that we see the 2268 * changes done by userspace on the next quotaon() */ 2269 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2270 if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { 2271 inode_lock(dqopt->files[cnt]); 2272 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 2273 inode_unlock(dqopt->files[cnt]); 2274 } 2275 if (sb->s_bdev) 2276 invalidate_bdev(sb->s_bdev); 2277 put_inodes: 2278 /* We are done when suspending quotas */ 2279 if (flags & DQUOT_SUSPENDED) 2280 return 0; 2281 2282 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2283 if (!sb_has_quota_loaded(sb, cnt)) 2284 vfs_cleanup_quota_inode(sb, cnt); 2285 return 0; 2286 } 2287 EXPORT_SYMBOL(dquot_disable); 2288 2289 int dquot_quota_off(struct super_block *sb, int type) 2290 { 2291 return dquot_disable(sb, type, 2292 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2293 } 2294 EXPORT_SYMBOL(dquot_quota_off); 2295 2296 /* 2297 * Turn quotas on on a device 2298 */ 2299 2300 static int vfs_setup_quota_inode(struct inode *inode, int type) 2301 { 2302 struct super_block *sb = inode->i_sb; 2303 struct quota_info *dqopt = sb_dqopt(sb); 2304 2305 if (!S_ISREG(inode->i_mode)) 2306 return -EACCES; 2307 if (IS_RDONLY(inode)) 2308 return -EROFS; 2309 if (sb_has_quota_loaded(sb, type)) 2310 return -EBUSY; 2311 2312 dqopt->files[type] = igrab(inode); 2313 if (!dqopt->files[type]) 2314 return -EIO; 2315 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2316 /* We don't want quota and atime on quota files (deadlocks 2317 * possible) Also nobody should write to the file - we use 2318 * special IO operations which ignore the immutable bit. */ 2319 inode_lock(inode); 2320 inode->i_flags |= S_NOQUOTA; 2321 inode_unlock(inode); 2322 /* 2323 * When S_NOQUOTA is set, remove dquot references as no more 2324 * references can be added 2325 */ 2326 __dquot_drop(inode); 2327 } 2328 return 0; 2329 } 2330 2331 int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, 2332 unsigned int flags) 2333 { 2334 struct quota_format_type *fmt = find_quota_format(format_id); 2335 struct quota_info *dqopt = sb_dqopt(sb); 2336 int error; 2337 2338 /* Just unsuspend quotas? */ 2339 BUG_ON(flags & DQUOT_SUSPENDED); 2340 /* s_umount should be held in exclusive mode */ 2341 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2342 up_read(&sb->s_umount); 2343 2344 if (!fmt) 2345 return -ESRCH; 2346 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2347 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2348 error = -EINVAL; 2349 goto out_fmt; 2350 } 2351 /* Filesystems outside of init_user_ns not yet supported */ 2352 if (sb->s_user_ns != &init_user_ns) { 2353 error = -EINVAL; 2354 goto out_fmt; 2355 } 2356 /* Usage always has to be set... */ 2357 if (!(flags & DQUOT_USAGE_ENABLED)) { 2358 error = -EINVAL; 2359 goto out_fmt; 2360 } 2361 if (sb_has_quota_loaded(sb, type)) { 2362 error = -EBUSY; 2363 goto out_fmt; 2364 } 2365 2366 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2367 /* As we bypass the pagecache we must now flush all the 2368 * dirty data and invalidate caches so that kernel sees 2369 * changes from userspace. It is not enough to just flush 2370 * the quota file since if blocksize < pagesize, invalidation 2371 * of the cache could fail because of other unrelated dirty 2372 * data */ 2373 sync_filesystem(sb); 2374 invalidate_bdev(sb->s_bdev); 2375 } 2376 2377 error = -EINVAL; 2378 if (!fmt->qf_ops->check_quota_file(sb, type)) 2379 goto out_fmt; 2380 2381 dqopt->ops[type] = fmt->qf_ops; 2382 dqopt->info[type].dqi_format = fmt; 2383 dqopt->info[type].dqi_fmt_id = format_id; 2384 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2385 error = dqopt->ops[type]->read_file_info(sb, type); 2386 if (error < 0) 2387 goto out_fmt; 2388 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2389 spin_lock(&dq_data_lock); 2390 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2391 spin_unlock(&dq_data_lock); 2392 } 2393 spin_lock(&dq_state_lock); 2394 dqopt->flags |= dquot_state_flag(flags, type); 2395 spin_unlock(&dq_state_lock); 2396 2397 error = add_dquot_ref(sb, type); 2398 if (error) 2399 dquot_disable(sb, type, flags); 2400 2401 return error; 2402 out_fmt: 2403 put_quota_format(fmt); 2404 2405 return error; 2406 } 2407 EXPORT_SYMBOL(dquot_load_quota_sb); 2408 2409 /* 2410 * More powerful function for turning on quotas on given quota inode allowing 2411 * setting of individual quota flags 2412 */ 2413 int dquot_load_quota_inode(struct inode *inode, int type, int format_id, 2414 unsigned int flags) 2415 { 2416 int err; 2417 2418 err = vfs_setup_quota_inode(inode, type); 2419 if (err < 0) 2420 return err; 2421 err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); 2422 if (err < 0) 2423 vfs_cleanup_quota_inode(inode->i_sb, type); 2424 return err; 2425 } 2426 EXPORT_SYMBOL(dquot_load_quota_inode); 2427 2428 /* Reenable quotas on remount RW */ 2429 int dquot_resume(struct super_block *sb, int type) 2430 { 2431 struct quota_info *dqopt = sb_dqopt(sb); 2432 int ret = 0, cnt; 2433 unsigned int flags; 2434 2435 /* s_umount should be held in exclusive mode */ 2436 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2437 up_read(&sb->s_umount); 2438 2439 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2440 if (type != -1 && cnt != type) 2441 continue; 2442 if (!sb_has_quota_suspended(sb, cnt)) 2443 continue; 2444 2445 spin_lock(&dq_state_lock); 2446 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2447 DQUOT_LIMITS_ENABLED, 2448 cnt); 2449 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2450 spin_unlock(&dq_state_lock); 2451 2452 flags = dquot_generic_flag(flags, cnt); 2453 ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, 2454 flags); 2455 if (ret < 0) 2456 vfs_cleanup_quota_inode(sb, cnt); 2457 } 2458 2459 return ret; 2460 } 2461 EXPORT_SYMBOL(dquot_resume); 2462 2463 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2464 const struct path *path) 2465 { 2466 int error = security_quota_on(path->dentry); 2467 if (error) 2468 return error; 2469 /* Quota file not on the same filesystem? */ 2470 if (path->dentry->d_sb != sb) 2471 error = -EXDEV; 2472 else 2473 error = dquot_load_quota_inode(d_inode(path->dentry), type, 2474 format_id, DQUOT_USAGE_ENABLED | 2475 DQUOT_LIMITS_ENABLED); 2476 return error; 2477 } 2478 EXPORT_SYMBOL(dquot_quota_on); 2479 2480 /* 2481 * This function is used when filesystem needs to initialize quotas 2482 * during mount time. 2483 */ 2484 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2485 int format_id, int type) 2486 { 2487 struct dentry *dentry; 2488 int error; 2489 2490 dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2491 if (IS_ERR(dentry)) 2492 return PTR_ERR(dentry); 2493 2494 error = security_quota_on(dentry); 2495 if (!error) 2496 error = dquot_load_quota_inode(d_inode(dentry), type, format_id, 2497 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2498 2499 dput(dentry); 2500 return error; 2501 } 2502 EXPORT_SYMBOL(dquot_quota_on_mount); 2503 2504 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2505 { 2506 int ret; 2507 int type; 2508 struct quota_info *dqopt = sb_dqopt(sb); 2509 2510 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2511 return -ENOSYS; 2512 /* Accounting cannot be turned on while fs is mounted */ 2513 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2514 if (!flags) 2515 return -EINVAL; 2516 for (type = 0; type < MAXQUOTAS; type++) { 2517 if (!(flags & qtype_enforce_flag(type))) 2518 continue; 2519 /* Can't enforce without accounting */ 2520 if (!sb_has_quota_usage_enabled(sb, type)) { 2521 ret = -EINVAL; 2522 goto out_err; 2523 } 2524 if (sb_has_quota_limits_enabled(sb, type)) { 2525 ret = -EBUSY; 2526 goto out_err; 2527 } 2528 spin_lock(&dq_state_lock); 2529 dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2530 spin_unlock(&dq_state_lock); 2531 } 2532 return 0; 2533 out_err: 2534 /* Backout enforcement enablement we already did */ 2535 for (type--; type >= 0; type--) { 2536 if (flags & qtype_enforce_flag(type)) 2537 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2538 } 2539 /* Error code translation for better compatibility with XFS */ 2540 if (ret == -EBUSY) 2541 ret = -EEXIST; 2542 return ret; 2543 } 2544 2545 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2546 { 2547 int ret; 2548 int type; 2549 struct quota_info *dqopt = sb_dqopt(sb); 2550 2551 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2552 return -ENOSYS; 2553 /* 2554 * We don't support turning off accounting via quotactl. In principle 2555 * quota infrastructure can do this but filesystems don't expect 2556 * userspace to be able to do it. 2557 */ 2558 if (flags & 2559 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2560 return -EOPNOTSUPP; 2561 2562 /* Filter out limits not enabled */ 2563 for (type = 0; type < MAXQUOTAS; type++) 2564 if (!sb_has_quota_limits_enabled(sb, type)) 2565 flags &= ~qtype_enforce_flag(type); 2566 /* Nothing left? */ 2567 if (!flags) 2568 return -EEXIST; 2569 for (type = 0; type < MAXQUOTAS; type++) { 2570 if (flags & qtype_enforce_flag(type)) { 2571 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2572 if (ret < 0) 2573 goto out_err; 2574 } 2575 } 2576 return 0; 2577 out_err: 2578 /* Backout enforcement disabling we already did */ 2579 for (type--; type >= 0; type--) { 2580 if (flags & qtype_enforce_flag(type)) { 2581 spin_lock(&dq_state_lock); 2582 dqopt->flags |= 2583 dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2584 spin_unlock(&dq_state_lock); 2585 } 2586 } 2587 return ret; 2588 } 2589 2590 /* Generic routine for getting common part of quota structure */ 2591 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2592 { 2593 struct mem_dqblk *dm = &dquot->dq_dqb; 2594 2595 memset(di, 0, sizeof(*di)); 2596 spin_lock(&dquot->dq_dqb_lock); 2597 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2598 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2599 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2600 di->d_ino_softlimit = dm->dqb_isoftlimit; 2601 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2602 di->d_ino_count = dm->dqb_curinodes; 2603 di->d_spc_timer = dm->dqb_btime; 2604 di->d_ino_timer = dm->dqb_itime; 2605 spin_unlock(&dquot->dq_dqb_lock); 2606 } 2607 2608 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2609 struct qc_dqblk *di) 2610 { 2611 struct dquot *dquot; 2612 2613 dquot = dqget(sb, qid); 2614 if (IS_ERR(dquot)) 2615 return PTR_ERR(dquot); 2616 do_get_dqblk(dquot, di); 2617 dqput(dquot); 2618 2619 return 0; 2620 } 2621 EXPORT_SYMBOL(dquot_get_dqblk); 2622 2623 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2624 struct qc_dqblk *di) 2625 { 2626 struct dquot *dquot; 2627 int err; 2628 2629 if (!sb->dq_op->get_next_id) 2630 return -ENOSYS; 2631 err = sb->dq_op->get_next_id(sb, qid); 2632 if (err < 0) 2633 return err; 2634 dquot = dqget(sb, *qid); 2635 if (IS_ERR(dquot)) 2636 return PTR_ERR(dquot); 2637 do_get_dqblk(dquot, di); 2638 dqput(dquot); 2639 2640 return 0; 2641 } 2642 EXPORT_SYMBOL(dquot_get_next_dqblk); 2643 2644 #define VFS_QC_MASK \ 2645 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2646 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2647 QC_SPC_TIMER | QC_INO_TIMER) 2648 2649 /* Generic routine for setting common part of quota structure */ 2650 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2651 { 2652 struct mem_dqblk *dm = &dquot->dq_dqb; 2653 int check_blim = 0, check_ilim = 0; 2654 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2655 2656 if (di->d_fieldmask & ~VFS_QC_MASK) 2657 return -EINVAL; 2658 2659 if (((di->d_fieldmask & QC_SPC_SOFT) && 2660 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2661 ((di->d_fieldmask & QC_SPC_HARD) && 2662 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2663 ((di->d_fieldmask & QC_INO_SOFT) && 2664 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2665 ((di->d_fieldmask & QC_INO_HARD) && 2666 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2667 return -ERANGE; 2668 2669 spin_lock(&dquot->dq_dqb_lock); 2670 if (di->d_fieldmask & QC_SPACE) { 2671 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2672 check_blim = 1; 2673 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2674 } 2675 2676 if (di->d_fieldmask & QC_SPC_SOFT) 2677 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2678 if (di->d_fieldmask & QC_SPC_HARD) 2679 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2680 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2681 check_blim = 1; 2682 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2683 } 2684 2685 if (di->d_fieldmask & QC_INO_COUNT) { 2686 dm->dqb_curinodes = di->d_ino_count; 2687 check_ilim = 1; 2688 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2689 } 2690 2691 if (di->d_fieldmask & QC_INO_SOFT) 2692 dm->dqb_isoftlimit = di->d_ino_softlimit; 2693 if (di->d_fieldmask & QC_INO_HARD) 2694 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2695 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2696 check_ilim = 1; 2697 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2698 } 2699 2700 if (di->d_fieldmask & QC_SPC_TIMER) { 2701 dm->dqb_btime = di->d_spc_timer; 2702 check_blim = 1; 2703 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2704 } 2705 2706 if (di->d_fieldmask & QC_INO_TIMER) { 2707 dm->dqb_itime = di->d_ino_timer; 2708 check_ilim = 1; 2709 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2710 } 2711 2712 if (check_blim) { 2713 if (!dm->dqb_bsoftlimit || 2714 dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) { 2715 dm->dqb_btime = 0; 2716 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2717 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2718 /* Set grace only if user hasn't provided his own... */ 2719 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2720 } 2721 if (check_ilim) { 2722 if (!dm->dqb_isoftlimit || 2723 dm->dqb_curinodes <= dm->dqb_isoftlimit) { 2724 dm->dqb_itime = 0; 2725 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2726 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2727 /* Set grace only if user hasn't provided his own... */ 2728 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2729 } 2730 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2731 dm->dqb_isoftlimit) 2732 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2733 else 2734 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2735 spin_unlock(&dquot->dq_dqb_lock); 2736 mark_dquot_dirty(dquot); 2737 2738 return 0; 2739 } 2740 2741 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2742 struct qc_dqblk *di) 2743 { 2744 struct dquot *dquot; 2745 int rc; 2746 2747 dquot = dqget(sb, qid); 2748 if (IS_ERR(dquot)) { 2749 rc = PTR_ERR(dquot); 2750 goto out; 2751 } 2752 rc = do_set_dqblk(dquot, di); 2753 dqput(dquot); 2754 out: 2755 return rc; 2756 } 2757 EXPORT_SYMBOL(dquot_set_dqblk); 2758 2759 /* Generic routine for getting common part of quota file information */ 2760 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2761 { 2762 struct mem_dqinfo *mi; 2763 struct qc_type_state *tstate; 2764 struct quota_info *dqopt = sb_dqopt(sb); 2765 int type; 2766 2767 memset(state, 0, sizeof(*state)); 2768 for (type = 0; type < MAXQUOTAS; type++) { 2769 if (!sb_has_quota_active(sb, type)) 2770 continue; 2771 tstate = state->s_state + type; 2772 mi = sb_dqopt(sb)->info + type; 2773 tstate->flags = QCI_ACCT_ENABLED; 2774 spin_lock(&dq_data_lock); 2775 if (mi->dqi_flags & DQF_SYS_FILE) 2776 tstate->flags |= QCI_SYSFILE; 2777 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2778 tstate->flags |= QCI_ROOT_SQUASH; 2779 if (sb_has_quota_limits_enabled(sb, type)) 2780 tstate->flags |= QCI_LIMITS_ENFORCED; 2781 tstate->spc_timelimit = mi->dqi_bgrace; 2782 tstate->ino_timelimit = mi->dqi_igrace; 2783 if (dqopt->files[type]) { 2784 tstate->ino = dqopt->files[type]->i_ino; 2785 tstate->blocks = dqopt->files[type]->i_blocks; 2786 } 2787 tstate->nextents = 1; /* We don't know... */ 2788 spin_unlock(&dq_data_lock); 2789 } 2790 return 0; 2791 } 2792 EXPORT_SYMBOL(dquot_get_state); 2793 2794 /* Generic routine for setting common part of quota file information */ 2795 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2796 { 2797 struct mem_dqinfo *mi; 2798 int err = 0; 2799 2800 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2801 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2802 return -EINVAL; 2803 if (!sb_has_quota_active(sb, type)) 2804 return -ESRCH; 2805 mi = sb_dqopt(sb)->info + type; 2806 if (ii->i_fieldmask & QC_FLAGS) { 2807 if ((ii->i_flags & QCI_ROOT_SQUASH && 2808 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2809 return -EINVAL; 2810 } 2811 spin_lock(&dq_data_lock); 2812 if (ii->i_fieldmask & QC_SPC_TIMER) 2813 mi->dqi_bgrace = ii->i_spc_timelimit; 2814 if (ii->i_fieldmask & QC_INO_TIMER) 2815 mi->dqi_igrace = ii->i_ino_timelimit; 2816 if (ii->i_fieldmask & QC_FLAGS) { 2817 if (ii->i_flags & QCI_ROOT_SQUASH) 2818 mi->dqi_flags |= DQF_ROOT_SQUASH; 2819 else 2820 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2821 } 2822 spin_unlock(&dq_data_lock); 2823 mark_info_dirty(sb, type); 2824 /* Force write to disk */ 2825 sb->dq_op->write_info(sb, type); 2826 return err; 2827 } 2828 EXPORT_SYMBOL(dquot_set_dqinfo); 2829 2830 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2831 .quota_enable = dquot_quota_enable, 2832 .quota_disable = dquot_quota_disable, 2833 .quota_sync = dquot_quota_sync, 2834 .get_state = dquot_get_state, 2835 .set_info = dquot_set_dqinfo, 2836 .get_dqblk = dquot_get_dqblk, 2837 .get_nextdqblk = dquot_get_next_dqblk, 2838 .set_dqblk = dquot_set_dqblk 2839 }; 2840 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2841 2842 static int do_proc_dqstats(struct ctl_table *table, int write, 2843 void *buffer, size_t *lenp, loff_t *ppos) 2844 { 2845 unsigned int type = (unsigned long *)table->data - dqstats.stat; 2846 s64 value = percpu_counter_sum(&dqstats.counter[type]); 2847 2848 /* Filter negative values for non-monotonic counters */ 2849 if (value < 0 && (type == DQST_ALLOC_DQUOTS || 2850 type == DQST_FREE_DQUOTS)) 2851 value = 0; 2852 2853 /* Update global table */ 2854 dqstats.stat[type] = value; 2855 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 2856 } 2857 2858 static struct ctl_table fs_dqstats_table[] = { 2859 { 2860 .procname = "lookups", 2861 .data = &dqstats.stat[DQST_LOOKUPS], 2862 .maxlen = sizeof(unsigned long), 2863 .mode = 0444, 2864 .proc_handler = do_proc_dqstats, 2865 }, 2866 { 2867 .procname = "drops", 2868 .data = &dqstats.stat[DQST_DROPS], 2869 .maxlen = sizeof(unsigned long), 2870 .mode = 0444, 2871 .proc_handler = do_proc_dqstats, 2872 }, 2873 { 2874 .procname = "reads", 2875 .data = &dqstats.stat[DQST_READS], 2876 .maxlen = sizeof(unsigned long), 2877 .mode = 0444, 2878 .proc_handler = do_proc_dqstats, 2879 }, 2880 { 2881 .procname = "writes", 2882 .data = &dqstats.stat[DQST_WRITES], 2883 .maxlen = sizeof(unsigned long), 2884 .mode = 0444, 2885 .proc_handler = do_proc_dqstats, 2886 }, 2887 { 2888 .procname = "cache_hits", 2889 .data = &dqstats.stat[DQST_CACHE_HITS], 2890 .maxlen = sizeof(unsigned long), 2891 .mode = 0444, 2892 .proc_handler = do_proc_dqstats, 2893 }, 2894 { 2895 .procname = "allocated_dquots", 2896 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2897 .maxlen = sizeof(unsigned long), 2898 .mode = 0444, 2899 .proc_handler = do_proc_dqstats, 2900 }, 2901 { 2902 .procname = "free_dquots", 2903 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2904 .maxlen = sizeof(unsigned long), 2905 .mode = 0444, 2906 .proc_handler = do_proc_dqstats, 2907 }, 2908 { 2909 .procname = "syncs", 2910 .data = &dqstats.stat[DQST_SYNCS], 2911 .maxlen = sizeof(unsigned long), 2912 .mode = 0444, 2913 .proc_handler = do_proc_dqstats, 2914 }, 2915 #ifdef CONFIG_PRINT_QUOTA_WARNING 2916 { 2917 .procname = "warnings", 2918 .data = &flag_print_warnings, 2919 .maxlen = sizeof(int), 2920 .mode = 0644, 2921 .proc_handler = proc_dointvec, 2922 }, 2923 #endif 2924 { }, 2925 }; 2926 2927 static struct ctl_table fs_table[] = { 2928 { 2929 .procname = "quota", 2930 .mode = 0555, 2931 .child = fs_dqstats_table, 2932 }, 2933 { }, 2934 }; 2935 2936 static struct ctl_table sys_table[] = { 2937 { 2938 .procname = "fs", 2939 .mode = 0555, 2940 .child = fs_table, 2941 }, 2942 { }, 2943 }; 2944 2945 static int __init dquot_init(void) 2946 { 2947 int i, ret; 2948 unsigned long nr_hash, order; 2949 2950 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2951 2952 register_sysctl_table(sys_table); 2953 2954 dquot_cachep = kmem_cache_create("dquot", 2955 sizeof(struct dquot), sizeof(unsigned long) * 4, 2956 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2957 SLAB_MEM_SPREAD|SLAB_PANIC), 2958 NULL); 2959 2960 order = 0; 2961 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2962 if (!dquot_hash) 2963 panic("Cannot create dquot hash table"); 2964 2965 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2966 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2967 if (ret) 2968 panic("Cannot create dquot stat counters"); 2969 } 2970 2971 /* Find power-of-two hlist_heads which can fit into allocation */ 2972 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2973 dq_hash_bits = ilog2(nr_hash); 2974 2975 nr_hash = 1UL << dq_hash_bits; 2976 dq_hash_mask = nr_hash - 1; 2977 for (i = 0; i < nr_hash; i++) 2978 INIT_HLIST_HEAD(dquot_hash + i); 2979 2980 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2981 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2982 2983 if (register_shrinker(&dqcache_shrinker)) 2984 panic("Cannot register dquot shrinker"); 2985 2986 return 0; 2987 } 2988 fs_initcall(dquot_init); 2989