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 ret = sb->s_op->sync_fs(sb, 1); 695 if (ret) 696 return ret; 697 } 698 ret = sync_blockdev(sb->s_bdev); 699 if (ret) 700 return ret; 701 702 /* 703 * Now when everything is written we can discard the pagecache so 704 * that userspace sees the changes. 705 */ 706 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 707 if (type != -1 && cnt != type) 708 continue; 709 if (!sb_has_quota_active(sb, cnt)) 710 continue; 711 inode_lock(dqopt->files[cnt]); 712 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 713 inode_unlock(dqopt->files[cnt]); 714 } 715 716 return 0; 717 } 718 EXPORT_SYMBOL(dquot_quota_sync); 719 720 static unsigned long 721 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 722 { 723 struct dquot *dquot; 724 unsigned long freed = 0; 725 726 spin_lock(&dq_list_lock); 727 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 728 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 729 remove_dquot_hash(dquot); 730 remove_free_dquot(dquot); 731 remove_inuse(dquot); 732 do_destroy_dquot(dquot); 733 sc->nr_to_scan--; 734 freed++; 735 } 736 spin_unlock(&dq_list_lock); 737 return freed; 738 } 739 740 static unsigned long 741 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 742 { 743 return vfs_pressure_ratio( 744 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 745 } 746 747 static struct shrinker dqcache_shrinker = { 748 .count_objects = dqcache_shrink_count, 749 .scan_objects = dqcache_shrink_scan, 750 .seeks = DEFAULT_SEEKS, 751 }; 752 753 /* 754 * Put reference to dquot 755 */ 756 void dqput(struct dquot *dquot) 757 { 758 int ret; 759 760 if (!dquot) 761 return; 762 #ifdef CONFIG_QUOTA_DEBUG 763 if (!atomic_read(&dquot->dq_count)) { 764 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 765 quotatypes[dquot->dq_id.type], 766 from_kqid(&init_user_ns, dquot->dq_id)); 767 BUG(); 768 } 769 #endif 770 dqstats_inc(DQST_DROPS); 771 we_slept: 772 spin_lock(&dq_list_lock); 773 if (atomic_read(&dquot->dq_count) > 1) { 774 /* We have more than one user... nothing to do */ 775 atomic_dec(&dquot->dq_count); 776 /* Releasing dquot during quotaoff phase? */ 777 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 778 atomic_read(&dquot->dq_count) == 1) 779 wake_up(&dquot_ref_wq); 780 spin_unlock(&dq_list_lock); 781 return; 782 } 783 /* Need to release dquot? */ 784 if (dquot_dirty(dquot)) { 785 spin_unlock(&dq_list_lock); 786 /* Commit dquot before releasing */ 787 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 788 if (ret < 0) { 789 quota_error(dquot->dq_sb, "Can't write quota structure" 790 " (error %d). Quota may get out of sync!", 791 ret); 792 /* 793 * We clear dirty bit anyway, so that we avoid 794 * infinite loop here 795 */ 796 clear_dquot_dirty(dquot); 797 } 798 goto we_slept; 799 } 800 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 801 spin_unlock(&dq_list_lock); 802 dquot->dq_sb->dq_op->release_dquot(dquot); 803 goto we_slept; 804 } 805 atomic_dec(&dquot->dq_count); 806 #ifdef CONFIG_QUOTA_DEBUG 807 /* sanity check */ 808 BUG_ON(!list_empty(&dquot->dq_free)); 809 #endif 810 put_dquot_last(dquot); 811 spin_unlock(&dq_list_lock); 812 } 813 EXPORT_SYMBOL(dqput); 814 815 struct dquot *dquot_alloc(struct super_block *sb, int type) 816 { 817 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 818 } 819 EXPORT_SYMBOL(dquot_alloc); 820 821 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 822 { 823 struct dquot *dquot; 824 825 dquot = sb->dq_op->alloc_dquot(sb, type); 826 if(!dquot) 827 return NULL; 828 829 mutex_init(&dquot->dq_lock); 830 INIT_LIST_HEAD(&dquot->dq_free); 831 INIT_LIST_HEAD(&dquot->dq_inuse); 832 INIT_HLIST_NODE(&dquot->dq_hash); 833 INIT_LIST_HEAD(&dquot->dq_dirty); 834 dquot->dq_sb = sb; 835 dquot->dq_id = make_kqid_invalid(type); 836 atomic_set(&dquot->dq_count, 1); 837 spin_lock_init(&dquot->dq_dqb_lock); 838 839 return dquot; 840 } 841 842 /* 843 * Get reference to dquot 844 * 845 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 846 * destroying our dquot by: 847 * a) checking for quota flags under dq_list_lock and 848 * b) getting a reference to dquot before we release dq_list_lock 849 */ 850 struct dquot *dqget(struct super_block *sb, struct kqid qid) 851 { 852 unsigned int hashent = hashfn(sb, qid); 853 struct dquot *dquot, *empty = NULL; 854 855 if (!qid_has_mapping(sb->s_user_ns, qid)) 856 return ERR_PTR(-EINVAL); 857 858 if (!sb_has_quota_active(sb, qid.type)) 859 return ERR_PTR(-ESRCH); 860 we_slept: 861 spin_lock(&dq_list_lock); 862 spin_lock(&dq_state_lock); 863 if (!sb_has_quota_active(sb, qid.type)) { 864 spin_unlock(&dq_state_lock); 865 spin_unlock(&dq_list_lock); 866 dquot = ERR_PTR(-ESRCH); 867 goto out; 868 } 869 spin_unlock(&dq_state_lock); 870 871 dquot = find_dquot(hashent, sb, qid); 872 if (!dquot) { 873 if (!empty) { 874 spin_unlock(&dq_list_lock); 875 empty = get_empty_dquot(sb, qid.type); 876 if (!empty) 877 schedule(); /* Try to wait for a moment... */ 878 goto we_slept; 879 } 880 dquot = empty; 881 empty = NULL; 882 dquot->dq_id = qid; 883 /* all dquots go on the inuse_list */ 884 put_inuse(dquot); 885 /* hash it first so it can be found */ 886 insert_dquot_hash(dquot); 887 spin_unlock(&dq_list_lock); 888 dqstats_inc(DQST_LOOKUPS); 889 } else { 890 if (!atomic_read(&dquot->dq_count)) 891 remove_free_dquot(dquot); 892 atomic_inc(&dquot->dq_count); 893 spin_unlock(&dq_list_lock); 894 dqstats_inc(DQST_CACHE_HITS); 895 dqstats_inc(DQST_LOOKUPS); 896 } 897 /* Wait for dq_lock - after this we know that either dquot_release() is 898 * already finished or it will be canceled due to dq_count > 1 test */ 899 wait_on_dquot(dquot); 900 /* Read the dquot / allocate space in quota file */ 901 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 902 int err; 903 904 err = sb->dq_op->acquire_dquot(dquot); 905 if (err < 0) { 906 dqput(dquot); 907 dquot = ERR_PTR(err); 908 goto out; 909 } 910 } 911 /* 912 * Make sure following reads see filled structure - paired with 913 * smp_mb__before_atomic() in dquot_acquire(). 914 */ 915 smp_rmb(); 916 #ifdef CONFIG_QUOTA_DEBUG 917 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 918 #endif 919 out: 920 if (empty) 921 do_destroy_dquot(empty); 922 923 return dquot; 924 } 925 EXPORT_SYMBOL(dqget); 926 927 static inline struct dquot **i_dquot(struct inode *inode) 928 { 929 return inode->i_sb->s_op->get_dquots(inode); 930 } 931 932 static int dqinit_needed(struct inode *inode, int type) 933 { 934 struct dquot * const *dquots; 935 int cnt; 936 937 if (IS_NOQUOTA(inode)) 938 return 0; 939 940 dquots = i_dquot(inode); 941 if (type != -1) 942 return !dquots[type]; 943 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 944 if (!dquots[cnt]) 945 return 1; 946 return 0; 947 } 948 949 /* This routine is guarded by s_umount semaphore */ 950 static int add_dquot_ref(struct super_block *sb, int type) 951 { 952 struct inode *inode, *old_inode = NULL; 953 #ifdef CONFIG_QUOTA_DEBUG 954 int reserved = 0; 955 #endif 956 int err = 0; 957 958 spin_lock(&sb->s_inode_list_lock); 959 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 960 spin_lock(&inode->i_lock); 961 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 962 !atomic_read(&inode->i_writecount) || 963 !dqinit_needed(inode, type)) { 964 spin_unlock(&inode->i_lock); 965 continue; 966 } 967 __iget(inode); 968 spin_unlock(&inode->i_lock); 969 spin_unlock(&sb->s_inode_list_lock); 970 971 #ifdef CONFIG_QUOTA_DEBUG 972 if (unlikely(inode_get_rsv_space(inode) > 0)) 973 reserved = 1; 974 #endif 975 iput(old_inode); 976 err = __dquot_initialize(inode, type); 977 if (err) { 978 iput(inode); 979 goto out; 980 } 981 982 /* 983 * We hold a reference to 'inode' so it couldn't have been 984 * removed from s_inodes list while we dropped the 985 * s_inode_list_lock. We cannot iput the inode now as we can be 986 * holding the last reference and we cannot iput it under 987 * s_inode_list_lock. So we keep the reference and iput it 988 * later. 989 */ 990 old_inode = inode; 991 cond_resched(); 992 spin_lock(&sb->s_inode_list_lock); 993 } 994 spin_unlock(&sb->s_inode_list_lock); 995 iput(old_inode); 996 out: 997 #ifdef CONFIG_QUOTA_DEBUG 998 if (reserved) { 999 quota_error(sb, "Writes happened before quota was turned on " 1000 "thus quota information is probably inconsistent. " 1001 "Please run quotacheck(8)"); 1002 } 1003 #endif 1004 return err; 1005 } 1006 1007 /* 1008 * Remove references to dquots from inode and add dquot to list for freeing 1009 * if we have the last reference to dquot 1010 */ 1011 static void remove_inode_dquot_ref(struct inode *inode, int type, 1012 struct list_head *tofree_head) 1013 { 1014 struct dquot **dquots = i_dquot(inode); 1015 struct dquot *dquot = dquots[type]; 1016 1017 if (!dquot) 1018 return; 1019 1020 dquots[type] = NULL; 1021 if (list_empty(&dquot->dq_free)) { 1022 /* 1023 * The inode still has reference to dquot so it can't be in the 1024 * free list 1025 */ 1026 spin_lock(&dq_list_lock); 1027 list_add(&dquot->dq_free, tofree_head); 1028 spin_unlock(&dq_list_lock); 1029 } else { 1030 /* 1031 * Dquot is already in a list to put so we won't drop the last 1032 * reference here. 1033 */ 1034 dqput(dquot); 1035 } 1036 } 1037 1038 /* 1039 * Free list of dquots 1040 * Dquots are removed from inodes and no new references can be got so we are 1041 * the only ones holding reference 1042 */ 1043 static void put_dquot_list(struct list_head *tofree_head) 1044 { 1045 struct list_head *act_head; 1046 struct dquot *dquot; 1047 1048 act_head = tofree_head->next; 1049 while (act_head != tofree_head) { 1050 dquot = list_entry(act_head, struct dquot, dq_free); 1051 act_head = act_head->next; 1052 /* Remove dquot from the list so we won't have problems... */ 1053 list_del_init(&dquot->dq_free); 1054 dqput(dquot); 1055 } 1056 } 1057 1058 static void remove_dquot_ref(struct super_block *sb, int type, 1059 struct list_head *tofree_head) 1060 { 1061 struct inode *inode; 1062 #ifdef CONFIG_QUOTA_DEBUG 1063 int reserved = 0; 1064 #endif 1065 1066 spin_lock(&sb->s_inode_list_lock); 1067 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1068 /* 1069 * We have to scan also I_NEW inodes because they can already 1070 * have quota pointer initialized. Luckily, we need to touch 1071 * only quota pointers and these have separate locking 1072 * (dq_data_lock). 1073 */ 1074 spin_lock(&dq_data_lock); 1075 if (!IS_NOQUOTA(inode)) { 1076 #ifdef CONFIG_QUOTA_DEBUG 1077 if (unlikely(inode_get_rsv_space(inode) > 0)) 1078 reserved = 1; 1079 #endif 1080 remove_inode_dquot_ref(inode, type, tofree_head); 1081 } 1082 spin_unlock(&dq_data_lock); 1083 } 1084 spin_unlock(&sb->s_inode_list_lock); 1085 #ifdef CONFIG_QUOTA_DEBUG 1086 if (reserved) { 1087 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1088 " was disabled thus quota information is probably " 1089 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1090 } 1091 #endif 1092 } 1093 1094 /* Gather all references from inodes and drop them */ 1095 static void drop_dquot_ref(struct super_block *sb, int type) 1096 { 1097 LIST_HEAD(tofree_head); 1098 1099 if (sb->dq_op) { 1100 remove_dquot_ref(sb, type, &tofree_head); 1101 synchronize_srcu(&dquot_srcu); 1102 put_dquot_list(&tofree_head); 1103 } 1104 } 1105 1106 static inline 1107 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1108 { 1109 if (dquot->dq_dqb.dqb_rsvspace >= number) 1110 dquot->dq_dqb.dqb_rsvspace -= number; 1111 else { 1112 WARN_ON_ONCE(1); 1113 dquot->dq_dqb.dqb_rsvspace = 0; 1114 } 1115 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1116 dquot->dq_dqb.dqb_bsoftlimit) 1117 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1118 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1119 } 1120 1121 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1122 { 1123 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1124 dquot->dq_dqb.dqb_curinodes >= number) 1125 dquot->dq_dqb.dqb_curinodes -= number; 1126 else 1127 dquot->dq_dqb.dqb_curinodes = 0; 1128 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1129 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1130 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1131 } 1132 1133 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1134 { 1135 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1136 dquot->dq_dqb.dqb_curspace >= number) 1137 dquot->dq_dqb.dqb_curspace -= number; 1138 else 1139 dquot->dq_dqb.dqb_curspace = 0; 1140 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1141 dquot->dq_dqb.dqb_bsoftlimit) 1142 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1143 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1144 } 1145 1146 struct dquot_warn { 1147 struct super_block *w_sb; 1148 struct kqid w_dq_id; 1149 short w_type; 1150 }; 1151 1152 static int warning_issued(struct dquot *dquot, const int warntype) 1153 { 1154 int flag = (warntype == QUOTA_NL_BHARDWARN || 1155 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1156 ((warntype == QUOTA_NL_IHARDWARN || 1157 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1158 1159 if (!flag) 1160 return 0; 1161 return test_and_set_bit(flag, &dquot->dq_flags); 1162 } 1163 1164 #ifdef CONFIG_PRINT_QUOTA_WARNING 1165 static int flag_print_warnings = 1; 1166 1167 static int need_print_warning(struct dquot_warn *warn) 1168 { 1169 if (!flag_print_warnings) 1170 return 0; 1171 1172 switch (warn->w_dq_id.type) { 1173 case USRQUOTA: 1174 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1175 case GRPQUOTA: 1176 return in_group_p(warn->w_dq_id.gid); 1177 case PRJQUOTA: 1178 return 1; 1179 } 1180 return 0; 1181 } 1182 1183 /* Print warning to user which exceeded quota */ 1184 static void print_warning(struct dquot_warn *warn) 1185 { 1186 char *msg = NULL; 1187 struct tty_struct *tty; 1188 int warntype = warn->w_type; 1189 1190 if (warntype == QUOTA_NL_IHARDBELOW || 1191 warntype == QUOTA_NL_ISOFTBELOW || 1192 warntype == QUOTA_NL_BHARDBELOW || 1193 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1194 return; 1195 1196 tty = get_current_tty(); 1197 if (!tty) 1198 return; 1199 tty_write_message(tty, warn->w_sb->s_id); 1200 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1201 tty_write_message(tty, ": warning, "); 1202 else 1203 tty_write_message(tty, ": write failed, "); 1204 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1205 switch (warntype) { 1206 case QUOTA_NL_IHARDWARN: 1207 msg = " file limit reached.\r\n"; 1208 break; 1209 case QUOTA_NL_ISOFTLONGWARN: 1210 msg = " file quota exceeded too long.\r\n"; 1211 break; 1212 case QUOTA_NL_ISOFTWARN: 1213 msg = " file quota exceeded.\r\n"; 1214 break; 1215 case QUOTA_NL_BHARDWARN: 1216 msg = " block limit reached.\r\n"; 1217 break; 1218 case QUOTA_NL_BSOFTLONGWARN: 1219 msg = " block quota exceeded too long.\r\n"; 1220 break; 1221 case QUOTA_NL_BSOFTWARN: 1222 msg = " block quota exceeded.\r\n"; 1223 break; 1224 } 1225 tty_write_message(tty, msg); 1226 tty_kref_put(tty); 1227 } 1228 #endif 1229 1230 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1231 int warntype) 1232 { 1233 if (warning_issued(dquot, warntype)) 1234 return; 1235 warn->w_type = warntype; 1236 warn->w_sb = dquot->dq_sb; 1237 warn->w_dq_id = dquot->dq_id; 1238 } 1239 1240 /* 1241 * Write warnings to the console and send warning messages over netlink. 1242 * 1243 * Note that this function can call into tty and networking code. 1244 */ 1245 static void flush_warnings(struct dquot_warn *warn) 1246 { 1247 int i; 1248 1249 for (i = 0; i < MAXQUOTAS; i++) { 1250 if (warn[i].w_type == QUOTA_NL_NOWARN) 1251 continue; 1252 #ifdef CONFIG_PRINT_QUOTA_WARNING 1253 print_warning(&warn[i]); 1254 #endif 1255 quota_send_warning(warn[i].w_dq_id, 1256 warn[i].w_sb->s_dev, warn[i].w_type); 1257 } 1258 } 1259 1260 static int ignore_hardlimit(struct dquot *dquot) 1261 { 1262 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1263 1264 return capable(CAP_SYS_RESOURCE) && 1265 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1266 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1267 } 1268 1269 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1270 struct dquot_warn *warn) 1271 { 1272 qsize_t newinodes; 1273 int ret = 0; 1274 1275 spin_lock(&dquot->dq_dqb_lock); 1276 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1277 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1278 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1279 goto add; 1280 1281 if (dquot->dq_dqb.dqb_ihardlimit && 1282 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1283 !ignore_hardlimit(dquot)) { 1284 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1285 ret = -EDQUOT; 1286 goto out; 1287 } 1288 1289 if (dquot->dq_dqb.dqb_isoftlimit && 1290 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1291 dquot->dq_dqb.dqb_itime && 1292 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1293 !ignore_hardlimit(dquot)) { 1294 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1295 ret = -EDQUOT; 1296 goto out; 1297 } 1298 1299 if (dquot->dq_dqb.dqb_isoftlimit && 1300 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1301 dquot->dq_dqb.dqb_itime == 0) { 1302 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1303 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1304 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1305 } 1306 add: 1307 dquot->dq_dqb.dqb_curinodes = newinodes; 1308 1309 out: 1310 spin_unlock(&dquot->dq_dqb_lock); 1311 return ret; 1312 } 1313 1314 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1315 qsize_t rsv_space, unsigned int flags, 1316 struct dquot_warn *warn) 1317 { 1318 qsize_t tspace; 1319 struct super_block *sb = dquot->dq_sb; 1320 int ret = 0; 1321 1322 spin_lock(&dquot->dq_dqb_lock); 1323 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1324 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1325 goto finish; 1326 1327 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1328 + space + rsv_space; 1329 1330 if (dquot->dq_dqb.dqb_bhardlimit && 1331 tspace > dquot->dq_dqb.dqb_bhardlimit && 1332 !ignore_hardlimit(dquot)) { 1333 if (flags & DQUOT_SPACE_WARN) 1334 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1335 ret = -EDQUOT; 1336 goto finish; 1337 } 1338 1339 if (dquot->dq_dqb.dqb_bsoftlimit && 1340 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1341 dquot->dq_dqb.dqb_btime && 1342 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1343 !ignore_hardlimit(dquot)) { 1344 if (flags & DQUOT_SPACE_WARN) 1345 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1346 ret = -EDQUOT; 1347 goto finish; 1348 } 1349 1350 if (dquot->dq_dqb.dqb_bsoftlimit && 1351 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1352 dquot->dq_dqb.dqb_btime == 0) { 1353 if (flags & DQUOT_SPACE_WARN) { 1354 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1355 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1356 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1357 } else { 1358 /* 1359 * We don't allow preallocation to exceed softlimit so exceeding will 1360 * be always printed 1361 */ 1362 ret = -EDQUOT; 1363 goto finish; 1364 } 1365 } 1366 finish: 1367 /* 1368 * We have to be careful and go through warning generation & grace time 1369 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1370 * only here... 1371 */ 1372 if (flags & DQUOT_SPACE_NOFAIL) 1373 ret = 0; 1374 if (!ret) { 1375 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1376 dquot->dq_dqb.dqb_curspace += space; 1377 } 1378 spin_unlock(&dquot->dq_dqb_lock); 1379 return ret; 1380 } 1381 1382 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1383 { 1384 qsize_t newinodes; 1385 1386 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1387 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1388 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1389 return QUOTA_NL_NOWARN; 1390 1391 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1392 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1393 return QUOTA_NL_ISOFTBELOW; 1394 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1395 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1396 return QUOTA_NL_IHARDBELOW; 1397 return QUOTA_NL_NOWARN; 1398 } 1399 1400 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1401 { 1402 qsize_t tspace; 1403 1404 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1405 1406 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1407 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1408 return QUOTA_NL_NOWARN; 1409 1410 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1411 return QUOTA_NL_BSOFTBELOW; 1412 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1413 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1414 return QUOTA_NL_BHARDBELOW; 1415 return QUOTA_NL_NOWARN; 1416 } 1417 1418 static int dquot_active(const struct inode *inode) 1419 { 1420 struct super_block *sb = inode->i_sb; 1421 1422 if (IS_NOQUOTA(inode)) 1423 return 0; 1424 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1425 } 1426 1427 /* 1428 * Initialize quota pointers in inode 1429 * 1430 * It is better to call this function outside of any transaction as it 1431 * might need a lot of space in journal for dquot structure allocation. 1432 */ 1433 static int __dquot_initialize(struct inode *inode, int type) 1434 { 1435 int cnt, init_needed = 0; 1436 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1437 struct super_block *sb = inode->i_sb; 1438 qsize_t rsv; 1439 int ret = 0; 1440 1441 if (!dquot_active(inode)) 1442 return 0; 1443 1444 dquots = i_dquot(inode); 1445 1446 /* First get references to structures we might need. */ 1447 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1448 struct kqid qid; 1449 kprojid_t projid; 1450 int rc; 1451 struct dquot *dquot; 1452 1453 if (type != -1 && cnt != type) 1454 continue; 1455 /* 1456 * The i_dquot should have been initialized in most cases, 1457 * we check it without locking here to avoid unnecessary 1458 * dqget()/dqput() calls. 1459 */ 1460 if (dquots[cnt]) 1461 continue; 1462 1463 if (!sb_has_quota_active(sb, cnt)) 1464 continue; 1465 1466 init_needed = 1; 1467 1468 switch (cnt) { 1469 case USRQUOTA: 1470 qid = make_kqid_uid(inode->i_uid); 1471 break; 1472 case GRPQUOTA: 1473 qid = make_kqid_gid(inode->i_gid); 1474 break; 1475 case PRJQUOTA: 1476 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1477 if (rc) 1478 continue; 1479 qid = make_kqid_projid(projid); 1480 break; 1481 } 1482 dquot = dqget(sb, qid); 1483 if (IS_ERR(dquot)) { 1484 /* We raced with somebody turning quotas off... */ 1485 if (PTR_ERR(dquot) != -ESRCH) { 1486 ret = PTR_ERR(dquot); 1487 goto out_put; 1488 } 1489 dquot = NULL; 1490 } 1491 got[cnt] = dquot; 1492 } 1493 1494 /* All required i_dquot has been initialized */ 1495 if (!init_needed) 1496 return 0; 1497 1498 spin_lock(&dq_data_lock); 1499 if (IS_NOQUOTA(inode)) 1500 goto out_lock; 1501 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1502 if (type != -1 && cnt != type) 1503 continue; 1504 /* Avoid races with quotaoff() */ 1505 if (!sb_has_quota_active(sb, cnt)) 1506 continue; 1507 /* We could race with quotaon or dqget() could have failed */ 1508 if (!got[cnt]) 1509 continue; 1510 if (!dquots[cnt]) { 1511 dquots[cnt] = got[cnt]; 1512 got[cnt] = NULL; 1513 /* 1514 * Make quota reservation system happy if someone 1515 * did a write before quota was turned on 1516 */ 1517 rsv = inode_get_rsv_space(inode); 1518 if (unlikely(rsv)) { 1519 spin_lock(&inode->i_lock); 1520 /* Get reservation again under proper lock */ 1521 rsv = __inode_get_rsv_space(inode); 1522 spin_lock(&dquots[cnt]->dq_dqb_lock); 1523 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1524 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1525 spin_unlock(&inode->i_lock); 1526 } 1527 } 1528 } 1529 out_lock: 1530 spin_unlock(&dq_data_lock); 1531 out_put: 1532 /* Drop unused references */ 1533 dqput_all(got); 1534 1535 return ret; 1536 } 1537 1538 int dquot_initialize(struct inode *inode) 1539 { 1540 return __dquot_initialize(inode, -1); 1541 } 1542 EXPORT_SYMBOL(dquot_initialize); 1543 1544 bool dquot_initialize_needed(struct inode *inode) 1545 { 1546 struct dquot **dquots; 1547 int i; 1548 1549 if (!dquot_active(inode)) 1550 return false; 1551 1552 dquots = i_dquot(inode); 1553 for (i = 0; i < MAXQUOTAS; i++) 1554 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1555 return true; 1556 return false; 1557 } 1558 EXPORT_SYMBOL(dquot_initialize_needed); 1559 1560 /* 1561 * Release all quotas referenced by inode. 1562 * 1563 * This function only be called on inode free or converting 1564 * a file to quota file, no other users for the i_dquot in 1565 * both cases, so we needn't call synchronize_srcu() after 1566 * clearing i_dquot. 1567 */ 1568 static void __dquot_drop(struct inode *inode) 1569 { 1570 int cnt; 1571 struct dquot **dquots = i_dquot(inode); 1572 struct dquot *put[MAXQUOTAS]; 1573 1574 spin_lock(&dq_data_lock); 1575 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1576 put[cnt] = dquots[cnt]; 1577 dquots[cnt] = NULL; 1578 } 1579 spin_unlock(&dq_data_lock); 1580 dqput_all(put); 1581 } 1582 1583 void dquot_drop(struct inode *inode) 1584 { 1585 struct dquot * const *dquots; 1586 int cnt; 1587 1588 if (IS_NOQUOTA(inode)) 1589 return; 1590 1591 /* 1592 * Test before calling to rule out calls from proc and such 1593 * where we are not allowed to block. Note that this is 1594 * actually reliable test even without the lock - the caller 1595 * must assure that nobody can come after the DQUOT_DROP and 1596 * add quota pointers back anyway. 1597 */ 1598 dquots = i_dquot(inode); 1599 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1600 if (dquots[cnt]) 1601 break; 1602 } 1603 1604 if (cnt < MAXQUOTAS) 1605 __dquot_drop(inode); 1606 } 1607 EXPORT_SYMBOL(dquot_drop); 1608 1609 /* 1610 * inode_reserved_space is managed internally by quota, and protected by 1611 * i_lock similar to i_blocks+i_bytes. 1612 */ 1613 static qsize_t *inode_reserved_space(struct inode * inode) 1614 { 1615 /* Filesystem must explicitly define it's own method in order to use 1616 * quota reservation interface */ 1617 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1618 return inode->i_sb->dq_op->get_reserved_space(inode); 1619 } 1620 1621 static qsize_t __inode_get_rsv_space(struct inode *inode) 1622 { 1623 if (!inode->i_sb->dq_op->get_reserved_space) 1624 return 0; 1625 return *inode_reserved_space(inode); 1626 } 1627 1628 static qsize_t inode_get_rsv_space(struct inode *inode) 1629 { 1630 qsize_t ret; 1631 1632 if (!inode->i_sb->dq_op->get_reserved_space) 1633 return 0; 1634 spin_lock(&inode->i_lock); 1635 ret = __inode_get_rsv_space(inode); 1636 spin_unlock(&inode->i_lock); 1637 return ret; 1638 } 1639 1640 /* 1641 * This functions updates i_blocks+i_bytes fields and quota information 1642 * (together with appropriate checks). 1643 * 1644 * NOTE: We absolutely rely on the fact that caller dirties the inode 1645 * (usually helpers in quotaops.h care about this) and holds a handle for 1646 * the current transaction so that dquot write and inode write go into the 1647 * same transaction. 1648 */ 1649 1650 /* 1651 * This operation can block, but only after everything is updated 1652 */ 1653 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1654 { 1655 int cnt, ret = 0, index; 1656 struct dquot_warn warn[MAXQUOTAS]; 1657 int reserve = flags & DQUOT_SPACE_RESERVE; 1658 struct dquot **dquots; 1659 1660 if (!dquot_active(inode)) { 1661 if (reserve) { 1662 spin_lock(&inode->i_lock); 1663 *inode_reserved_space(inode) += number; 1664 spin_unlock(&inode->i_lock); 1665 } else { 1666 inode_add_bytes(inode, number); 1667 } 1668 goto out; 1669 } 1670 1671 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1672 warn[cnt].w_type = QUOTA_NL_NOWARN; 1673 1674 dquots = i_dquot(inode); 1675 index = srcu_read_lock(&dquot_srcu); 1676 spin_lock(&inode->i_lock); 1677 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1678 if (!dquots[cnt]) 1679 continue; 1680 if (reserve) { 1681 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1682 &warn[cnt]); 1683 } else { 1684 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1685 &warn[cnt]); 1686 } 1687 if (ret) { 1688 /* Back out changes we already did */ 1689 for (cnt--; cnt >= 0; cnt--) { 1690 if (!dquots[cnt]) 1691 continue; 1692 spin_lock(&dquots[cnt]->dq_dqb_lock); 1693 if (reserve) 1694 dquot_free_reserved_space(dquots[cnt], 1695 number); 1696 else 1697 dquot_decr_space(dquots[cnt], number); 1698 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1699 } 1700 spin_unlock(&inode->i_lock); 1701 goto out_flush_warn; 1702 } 1703 } 1704 if (reserve) 1705 *inode_reserved_space(inode) += number; 1706 else 1707 __inode_add_bytes(inode, number); 1708 spin_unlock(&inode->i_lock); 1709 1710 if (reserve) 1711 goto out_flush_warn; 1712 mark_all_dquot_dirty(dquots); 1713 out_flush_warn: 1714 srcu_read_unlock(&dquot_srcu, index); 1715 flush_warnings(warn); 1716 out: 1717 return ret; 1718 } 1719 EXPORT_SYMBOL(__dquot_alloc_space); 1720 1721 /* 1722 * This operation can block, but only after everything is updated 1723 */ 1724 int dquot_alloc_inode(struct inode *inode) 1725 { 1726 int cnt, ret = 0, index; 1727 struct dquot_warn warn[MAXQUOTAS]; 1728 struct dquot * const *dquots; 1729 1730 if (!dquot_active(inode)) 1731 return 0; 1732 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1733 warn[cnt].w_type = QUOTA_NL_NOWARN; 1734 1735 dquots = i_dquot(inode); 1736 index = srcu_read_lock(&dquot_srcu); 1737 spin_lock(&inode->i_lock); 1738 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1739 if (!dquots[cnt]) 1740 continue; 1741 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1742 if (ret) { 1743 for (cnt--; cnt >= 0; cnt--) { 1744 if (!dquots[cnt]) 1745 continue; 1746 /* Back out changes we already did */ 1747 spin_lock(&dquots[cnt]->dq_dqb_lock); 1748 dquot_decr_inodes(dquots[cnt], 1); 1749 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1750 } 1751 goto warn_put_all; 1752 } 1753 } 1754 1755 warn_put_all: 1756 spin_unlock(&inode->i_lock); 1757 if (ret == 0) 1758 mark_all_dquot_dirty(dquots); 1759 srcu_read_unlock(&dquot_srcu, index); 1760 flush_warnings(warn); 1761 return ret; 1762 } 1763 EXPORT_SYMBOL(dquot_alloc_inode); 1764 1765 /* 1766 * Convert in-memory reserved quotas to real consumed quotas 1767 */ 1768 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1769 { 1770 struct dquot **dquots; 1771 int cnt, index; 1772 1773 if (!dquot_active(inode)) { 1774 spin_lock(&inode->i_lock); 1775 *inode_reserved_space(inode) -= number; 1776 __inode_add_bytes(inode, number); 1777 spin_unlock(&inode->i_lock); 1778 return 0; 1779 } 1780 1781 dquots = i_dquot(inode); 1782 index = srcu_read_lock(&dquot_srcu); 1783 spin_lock(&inode->i_lock); 1784 /* Claim reserved quotas to allocated quotas */ 1785 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1786 if (dquots[cnt]) { 1787 struct dquot *dquot = dquots[cnt]; 1788 1789 spin_lock(&dquot->dq_dqb_lock); 1790 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1791 number = dquot->dq_dqb.dqb_rsvspace; 1792 dquot->dq_dqb.dqb_curspace += number; 1793 dquot->dq_dqb.dqb_rsvspace -= number; 1794 spin_unlock(&dquot->dq_dqb_lock); 1795 } 1796 } 1797 /* Update inode bytes */ 1798 *inode_reserved_space(inode) -= number; 1799 __inode_add_bytes(inode, number); 1800 spin_unlock(&inode->i_lock); 1801 mark_all_dquot_dirty(dquots); 1802 srcu_read_unlock(&dquot_srcu, index); 1803 return 0; 1804 } 1805 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1806 1807 /* 1808 * Convert allocated space back to in-memory reserved quotas 1809 */ 1810 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1811 { 1812 struct dquot **dquots; 1813 int cnt, index; 1814 1815 if (!dquot_active(inode)) { 1816 spin_lock(&inode->i_lock); 1817 *inode_reserved_space(inode) += number; 1818 __inode_sub_bytes(inode, number); 1819 spin_unlock(&inode->i_lock); 1820 return; 1821 } 1822 1823 dquots = i_dquot(inode); 1824 index = srcu_read_lock(&dquot_srcu); 1825 spin_lock(&inode->i_lock); 1826 /* Claim reserved quotas to allocated quotas */ 1827 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1828 if (dquots[cnt]) { 1829 struct dquot *dquot = dquots[cnt]; 1830 1831 spin_lock(&dquot->dq_dqb_lock); 1832 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1833 number = dquot->dq_dqb.dqb_curspace; 1834 dquot->dq_dqb.dqb_rsvspace += number; 1835 dquot->dq_dqb.dqb_curspace -= number; 1836 spin_unlock(&dquot->dq_dqb_lock); 1837 } 1838 } 1839 /* Update inode bytes */ 1840 *inode_reserved_space(inode) += number; 1841 __inode_sub_bytes(inode, number); 1842 spin_unlock(&inode->i_lock); 1843 mark_all_dquot_dirty(dquots); 1844 srcu_read_unlock(&dquot_srcu, index); 1845 return; 1846 } 1847 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1848 1849 /* 1850 * This operation can block, but only after everything is updated 1851 */ 1852 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1853 { 1854 unsigned int cnt; 1855 struct dquot_warn warn[MAXQUOTAS]; 1856 struct dquot **dquots; 1857 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1858 1859 if (!dquot_active(inode)) { 1860 if (reserve) { 1861 spin_lock(&inode->i_lock); 1862 *inode_reserved_space(inode) -= number; 1863 spin_unlock(&inode->i_lock); 1864 } else { 1865 inode_sub_bytes(inode, number); 1866 } 1867 return; 1868 } 1869 1870 dquots = i_dquot(inode); 1871 index = srcu_read_lock(&dquot_srcu); 1872 spin_lock(&inode->i_lock); 1873 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1874 int wtype; 1875 1876 warn[cnt].w_type = QUOTA_NL_NOWARN; 1877 if (!dquots[cnt]) 1878 continue; 1879 spin_lock(&dquots[cnt]->dq_dqb_lock); 1880 wtype = info_bdq_free(dquots[cnt], number); 1881 if (wtype != QUOTA_NL_NOWARN) 1882 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1883 if (reserve) 1884 dquot_free_reserved_space(dquots[cnt], number); 1885 else 1886 dquot_decr_space(dquots[cnt], number); 1887 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1888 } 1889 if (reserve) 1890 *inode_reserved_space(inode) -= number; 1891 else 1892 __inode_sub_bytes(inode, number); 1893 spin_unlock(&inode->i_lock); 1894 1895 if (reserve) 1896 goto out_unlock; 1897 mark_all_dquot_dirty(dquots); 1898 out_unlock: 1899 srcu_read_unlock(&dquot_srcu, index); 1900 flush_warnings(warn); 1901 } 1902 EXPORT_SYMBOL(__dquot_free_space); 1903 1904 /* 1905 * This operation can block, but only after everything is updated 1906 */ 1907 void dquot_free_inode(struct inode *inode) 1908 { 1909 unsigned int cnt; 1910 struct dquot_warn warn[MAXQUOTAS]; 1911 struct dquot * const *dquots; 1912 int index; 1913 1914 if (!dquot_active(inode)) 1915 return; 1916 1917 dquots = i_dquot(inode); 1918 index = srcu_read_lock(&dquot_srcu); 1919 spin_lock(&inode->i_lock); 1920 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1921 int wtype; 1922 1923 warn[cnt].w_type = QUOTA_NL_NOWARN; 1924 if (!dquots[cnt]) 1925 continue; 1926 spin_lock(&dquots[cnt]->dq_dqb_lock); 1927 wtype = info_idq_free(dquots[cnt], 1); 1928 if (wtype != QUOTA_NL_NOWARN) 1929 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1930 dquot_decr_inodes(dquots[cnt], 1); 1931 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1932 } 1933 spin_unlock(&inode->i_lock); 1934 mark_all_dquot_dirty(dquots); 1935 srcu_read_unlock(&dquot_srcu, index); 1936 flush_warnings(warn); 1937 } 1938 EXPORT_SYMBOL(dquot_free_inode); 1939 1940 /* 1941 * Transfer the number of inode and blocks from one diskquota to an other. 1942 * On success, dquot references in transfer_to are consumed and references 1943 * to original dquots that need to be released are placed there. On failure, 1944 * references are kept untouched. 1945 * 1946 * This operation can block, but only after everything is updated 1947 * A transaction must be started when entering this function. 1948 * 1949 * We are holding reference on transfer_from & transfer_to, no need to 1950 * protect them by srcu_read_lock(). 1951 */ 1952 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1953 { 1954 qsize_t cur_space; 1955 qsize_t rsv_space = 0; 1956 qsize_t inode_usage = 1; 1957 struct dquot *transfer_from[MAXQUOTAS] = {}; 1958 int cnt, ret = 0; 1959 char is_valid[MAXQUOTAS] = {}; 1960 struct dquot_warn warn_to[MAXQUOTAS]; 1961 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1962 struct dquot_warn warn_from_space[MAXQUOTAS]; 1963 1964 if (IS_NOQUOTA(inode)) 1965 return 0; 1966 1967 if (inode->i_sb->dq_op->get_inode_usage) { 1968 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1969 if (ret) 1970 return ret; 1971 } 1972 1973 /* Initialize the arrays */ 1974 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1975 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1976 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1977 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1978 } 1979 1980 spin_lock(&dq_data_lock); 1981 spin_lock(&inode->i_lock); 1982 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1983 spin_unlock(&inode->i_lock); 1984 spin_unlock(&dq_data_lock); 1985 return 0; 1986 } 1987 cur_space = __inode_get_bytes(inode); 1988 rsv_space = __inode_get_rsv_space(inode); 1989 /* 1990 * Build the transfer_from list, check limits, and update usage in 1991 * the target structures. 1992 */ 1993 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1994 /* 1995 * Skip changes for same uid or gid or for turned off quota-type. 1996 */ 1997 if (!transfer_to[cnt]) 1998 continue; 1999 /* Avoid races with quotaoff() */ 2000 if (!sb_has_quota_active(inode->i_sb, cnt)) 2001 continue; 2002 is_valid[cnt] = 1; 2003 transfer_from[cnt] = i_dquot(inode)[cnt]; 2004 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 2005 &warn_to[cnt]); 2006 if (ret) 2007 goto over_quota; 2008 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 2009 DQUOT_SPACE_WARN, &warn_to[cnt]); 2010 if (ret) { 2011 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2012 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2013 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2014 goto over_quota; 2015 } 2016 } 2017 2018 /* Decrease usage for source structures and update quota pointers */ 2019 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2020 if (!is_valid[cnt]) 2021 continue; 2022 /* Due to IO error we might not have transfer_from[] structure */ 2023 if (transfer_from[cnt]) { 2024 int wtype; 2025 2026 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2027 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2028 if (wtype != QUOTA_NL_NOWARN) 2029 prepare_warning(&warn_from_inodes[cnt], 2030 transfer_from[cnt], wtype); 2031 wtype = info_bdq_free(transfer_from[cnt], 2032 cur_space + rsv_space); 2033 if (wtype != QUOTA_NL_NOWARN) 2034 prepare_warning(&warn_from_space[cnt], 2035 transfer_from[cnt], wtype); 2036 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2037 dquot_decr_space(transfer_from[cnt], cur_space); 2038 dquot_free_reserved_space(transfer_from[cnt], 2039 rsv_space); 2040 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2041 } 2042 i_dquot(inode)[cnt] = transfer_to[cnt]; 2043 } 2044 spin_unlock(&inode->i_lock); 2045 spin_unlock(&dq_data_lock); 2046 2047 mark_all_dquot_dirty(transfer_from); 2048 mark_all_dquot_dirty(transfer_to); 2049 flush_warnings(warn_to); 2050 flush_warnings(warn_from_inodes); 2051 flush_warnings(warn_from_space); 2052 /* Pass back references to put */ 2053 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2054 if (is_valid[cnt]) 2055 transfer_to[cnt] = transfer_from[cnt]; 2056 return 0; 2057 over_quota: 2058 /* Back out changes we already did */ 2059 for (cnt--; cnt >= 0; cnt--) { 2060 if (!is_valid[cnt]) 2061 continue; 2062 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2063 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2064 dquot_decr_space(transfer_to[cnt], cur_space); 2065 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2066 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2067 } 2068 spin_unlock(&inode->i_lock); 2069 spin_unlock(&dq_data_lock); 2070 flush_warnings(warn_to); 2071 return ret; 2072 } 2073 EXPORT_SYMBOL(__dquot_transfer); 2074 2075 /* Wrapper for transferring ownership of an inode for uid/gid only 2076 * Called from FSXXX_setattr() 2077 */ 2078 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2079 { 2080 struct dquot *transfer_to[MAXQUOTAS] = {}; 2081 struct dquot *dquot; 2082 struct super_block *sb = inode->i_sb; 2083 int ret; 2084 2085 if (!dquot_active(inode)) 2086 return 0; 2087 2088 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2089 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2090 if (IS_ERR(dquot)) { 2091 if (PTR_ERR(dquot) != -ESRCH) { 2092 ret = PTR_ERR(dquot); 2093 goto out_put; 2094 } 2095 dquot = NULL; 2096 } 2097 transfer_to[USRQUOTA] = dquot; 2098 } 2099 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2100 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2101 if (IS_ERR(dquot)) { 2102 if (PTR_ERR(dquot) != -ESRCH) { 2103 ret = PTR_ERR(dquot); 2104 goto out_put; 2105 } 2106 dquot = NULL; 2107 } 2108 transfer_to[GRPQUOTA] = dquot; 2109 } 2110 ret = __dquot_transfer(inode, transfer_to); 2111 out_put: 2112 dqput_all(transfer_to); 2113 return ret; 2114 } 2115 EXPORT_SYMBOL(dquot_transfer); 2116 2117 /* 2118 * Write info of quota file to disk 2119 */ 2120 int dquot_commit_info(struct super_block *sb, int type) 2121 { 2122 struct quota_info *dqopt = sb_dqopt(sb); 2123 2124 return dqopt->ops[type]->write_file_info(sb, type); 2125 } 2126 EXPORT_SYMBOL(dquot_commit_info); 2127 2128 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2129 { 2130 struct quota_info *dqopt = sb_dqopt(sb); 2131 2132 if (!sb_has_quota_active(sb, qid->type)) 2133 return -ESRCH; 2134 if (!dqopt->ops[qid->type]->get_next_id) 2135 return -ENOSYS; 2136 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2137 } 2138 EXPORT_SYMBOL(dquot_get_next_id); 2139 2140 /* 2141 * Definitions of diskquota operations. 2142 */ 2143 const struct dquot_operations dquot_operations = { 2144 .write_dquot = dquot_commit, 2145 .acquire_dquot = dquot_acquire, 2146 .release_dquot = dquot_release, 2147 .mark_dirty = dquot_mark_dquot_dirty, 2148 .write_info = dquot_commit_info, 2149 .alloc_dquot = dquot_alloc, 2150 .destroy_dquot = dquot_destroy, 2151 .get_next_id = dquot_get_next_id, 2152 }; 2153 EXPORT_SYMBOL(dquot_operations); 2154 2155 /* 2156 * Generic helper for ->open on filesystems supporting disk quotas. 2157 */ 2158 int dquot_file_open(struct inode *inode, struct file *file) 2159 { 2160 int error; 2161 2162 error = generic_file_open(inode, file); 2163 if (!error && (file->f_mode & FMODE_WRITE)) 2164 error = dquot_initialize(inode); 2165 return error; 2166 } 2167 EXPORT_SYMBOL(dquot_file_open); 2168 2169 static void vfs_cleanup_quota_inode(struct super_block *sb, int type) 2170 { 2171 struct quota_info *dqopt = sb_dqopt(sb); 2172 struct inode *inode = dqopt->files[type]; 2173 2174 if (!inode) 2175 return; 2176 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2177 inode_lock(inode); 2178 inode->i_flags &= ~S_NOQUOTA; 2179 inode_unlock(inode); 2180 } 2181 dqopt->files[type] = NULL; 2182 iput(inode); 2183 } 2184 2185 /* 2186 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2187 */ 2188 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2189 { 2190 int cnt; 2191 struct quota_info *dqopt = sb_dqopt(sb); 2192 2193 /* s_umount should be held in exclusive mode */ 2194 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2195 up_read(&sb->s_umount); 2196 2197 /* Cannot turn off usage accounting without turning off limits, or 2198 * suspend quotas and simultaneously turn quotas off. */ 2199 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2200 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2201 DQUOT_USAGE_ENABLED))) 2202 return -EINVAL; 2203 2204 /* 2205 * Skip everything if there's nothing to do. We have to do this because 2206 * sometimes we are called when fill_super() failed and calling 2207 * sync_fs() in such cases does no good. 2208 */ 2209 if (!sb_any_quota_loaded(sb)) 2210 return 0; 2211 2212 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2213 if (type != -1 && cnt != type) 2214 continue; 2215 if (!sb_has_quota_loaded(sb, cnt)) 2216 continue; 2217 2218 if (flags & DQUOT_SUSPENDED) { 2219 spin_lock(&dq_state_lock); 2220 dqopt->flags |= 2221 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2222 spin_unlock(&dq_state_lock); 2223 } else { 2224 spin_lock(&dq_state_lock); 2225 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2226 /* Turning off suspended quotas? */ 2227 if (!sb_has_quota_loaded(sb, cnt) && 2228 sb_has_quota_suspended(sb, cnt)) { 2229 dqopt->flags &= ~dquot_state_flag( 2230 DQUOT_SUSPENDED, cnt); 2231 spin_unlock(&dq_state_lock); 2232 vfs_cleanup_quota_inode(sb, cnt); 2233 continue; 2234 } 2235 spin_unlock(&dq_state_lock); 2236 } 2237 2238 /* We still have to keep quota loaded? */ 2239 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2240 continue; 2241 2242 /* Note: these are blocking operations */ 2243 drop_dquot_ref(sb, cnt); 2244 invalidate_dquots(sb, cnt); 2245 /* 2246 * Now all dquots should be invalidated, all writes done so we 2247 * should be only users of the info. No locks needed. 2248 */ 2249 if (info_dirty(&dqopt->info[cnt])) 2250 sb->dq_op->write_info(sb, cnt); 2251 if (dqopt->ops[cnt]->free_file_info) 2252 dqopt->ops[cnt]->free_file_info(sb, cnt); 2253 put_quota_format(dqopt->info[cnt].dqi_format); 2254 dqopt->info[cnt].dqi_flags = 0; 2255 dqopt->info[cnt].dqi_igrace = 0; 2256 dqopt->info[cnt].dqi_bgrace = 0; 2257 dqopt->ops[cnt] = NULL; 2258 } 2259 2260 /* Skip syncing and setting flags if quota files are hidden */ 2261 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2262 goto put_inodes; 2263 2264 /* Sync the superblock so that buffers with quota data are written to 2265 * disk (and so userspace sees correct data afterwards). */ 2266 if (sb->s_op->sync_fs) 2267 sb->s_op->sync_fs(sb, 1); 2268 sync_blockdev(sb->s_bdev); 2269 /* Now the quota files are just ordinary files and we can set the 2270 * inode flags back. Moreover we discard the pagecache so that 2271 * userspace sees the writes we did bypassing the pagecache. We 2272 * must also discard the blockdev buffers so that we see the 2273 * changes done by userspace on the next quotaon() */ 2274 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2275 if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { 2276 inode_lock(dqopt->files[cnt]); 2277 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 2278 inode_unlock(dqopt->files[cnt]); 2279 } 2280 if (sb->s_bdev) 2281 invalidate_bdev(sb->s_bdev); 2282 put_inodes: 2283 /* We are done when suspending quotas */ 2284 if (flags & DQUOT_SUSPENDED) 2285 return 0; 2286 2287 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2288 if (!sb_has_quota_loaded(sb, cnt)) 2289 vfs_cleanup_quota_inode(sb, cnt); 2290 return 0; 2291 } 2292 EXPORT_SYMBOL(dquot_disable); 2293 2294 int dquot_quota_off(struct super_block *sb, int type) 2295 { 2296 return dquot_disable(sb, type, 2297 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2298 } 2299 EXPORT_SYMBOL(dquot_quota_off); 2300 2301 /* 2302 * Turn quotas on on a device 2303 */ 2304 2305 static int vfs_setup_quota_inode(struct inode *inode, int type) 2306 { 2307 struct super_block *sb = inode->i_sb; 2308 struct quota_info *dqopt = sb_dqopt(sb); 2309 2310 if (!S_ISREG(inode->i_mode)) 2311 return -EACCES; 2312 if (IS_RDONLY(inode)) 2313 return -EROFS; 2314 if (sb_has_quota_loaded(sb, type)) 2315 return -EBUSY; 2316 2317 dqopt->files[type] = igrab(inode); 2318 if (!dqopt->files[type]) 2319 return -EIO; 2320 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2321 /* We don't want quota and atime on quota files (deadlocks 2322 * possible) Also nobody should write to the file - we use 2323 * special IO operations which ignore the immutable bit. */ 2324 inode_lock(inode); 2325 inode->i_flags |= S_NOQUOTA; 2326 inode_unlock(inode); 2327 /* 2328 * When S_NOQUOTA is set, remove dquot references as no more 2329 * references can be added 2330 */ 2331 __dquot_drop(inode); 2332 } 2333 return 0; 2334 } 2335 2336 int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, 2337 unsigned int flags) 2338 { 2339 struct quota_format_type *fmt = find_quota_format(format_id); 2340 struct quota_info *dqopt = sb_dqopt(sb); 2341 int error; 2342 2343 /* Just unsuspend quotas? */ 2344 BUG_ON(flags & DQUOT_SUSPENDED); 2345 /* s_umount should be held in exclusive mode */ 2346 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2347 up_read(&sb->s_umount); 2348 2349 if (!fmt) 2350 return -ESRCH; 2351 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2352 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2353 error = -EINVAL; 2354 goto out_fmt; 2355 } 2356 /* Filesystems outside of init_user_ns not yet supported */ 2357 if (sb->s_user_ns != &init_user_ns) { 2358 error = -EINVAL; 2359 goto out_fmt; 2360 } 2361 /* Usage always has to be set... */ 2362 if (!(flags & DQUOT_USAGE_ENABLED)) { 2363 error = -EINVAL; 2364 goto out_fmt; 2365 } 2366 if (sb_has_quota_loaded(sb, type)) { 2367 error = -EBUSY; 2368 goto out_fmt; 2369 } 2370 2371 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2372 /* As we bypass the pagecache we must now flush all the 2373 * dirty data and invalidate caches so that kernel sees 2374 * changes from userspace. It is not enough to just flush 2375 * the quota file since if blocksize < pagesize, invalidation 2376 * of the cache could fail because of other unrelated dirty 2377 * data */ 2378 sync_filesystem(sb); 2379 invalidate_bdev(sb->s_bdev); 2380 } 2381 2382 error = -EINVAL; 2383 if (!fmt->qf_ops->check_quota_file(sb, type)) 2384 goto out_fmt; 2385 2386 dqopt->ops[type] = fmt->qf_ops; 2387 dqopt->info[type].dqi_format = fmt; 2388 dqopt->info[type].dqi_fmt_id = format_id; 2389 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2390 error = dqopt->ops[type]->read_file_info(sb, type); 2391 if (error < 0) 2392 goto out_fmt; 2393 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2394 spin_lock(&dq_data_lock); 2395 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2396 spin_unlock(&dq_data_lock); 2397 } 2398 spin_lock(&dq_state_lock); 2399 dqopt->flags |= dquot_state_flag(flags, type); 2400 spin_unlock(&dq_state_lock); 2401 2402 error = add_dquot_ref(sb, type); 2403 if (error) 2404 dquot_disable(sb, type, flags); 2405 2406 return error; 2407 out_fmt: 2408 put_quota_format(fmt); 2409 2410 return error; 2411 } 2412 EXPORT_SYMBOL(dquot_load_quota_sb); 2413 2414 /* 2415 * More powerful function for turning on quotas on given quota inode allowing 2416 * setting of individual quota flags 2417 */ 2418 int dquot_load_quota_inode(struct inode *inode, int type, int format_id, 2419 unsigned int flags) 2420 { 2421 int err; 2422 2423 err = vfs_setup_quota_inode(inode, type); 2424 if (err < 0) 2425 return err; 2426 err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); 2427 if (err < 0) 2428 vfs_cleanup_quota_inode(inode->i_sb, type); 2429 return err; 2430 } 2431 EXPORT_SYMBOL(dquot_load_quota_inode); 2432 2433 /* Reenable quotas on remount RW */ 2434 int dquot_resume(struct super_block *sb, int type) 2435 { 2436 struct quota_info *dqopt = sb_dqopt(sb); 2437 int ret = 0, cnt; 2438 unsigned int flags; 2439 2440 /* s_umount should be held in exclusive mode */ 2441 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2442 up_read(&sb->s_umount); 2443 2444 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2445 if (type != -1 && cnt != type) 2446 continue; 2447 if (!sb_has_quota_suspended(sb, cnt)) 2448 continue; 2449 2450 spin_lock(&dq_state_lock); 2451 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2452 DQUOT_LIMITS_ENABLED, 2453 cnt); 2454 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2455 spin_unlock(&dq_state_lock); 2456 2457 flags = dquot_generic_flag(flags, cnt); 2458 ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, 2459 flags); 2460 if (ret < 0) 2461 vfs_cleanup_quota_inode(sb, cnt); 2462 } 2463 2464 return ret; 2465 } 2466 EXPORT_SYMBOL(dquot_resume); 2467 2468 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2469 const struct path *path) 2470 { 2471 int error = security_quota_on(path->dentry); 2472 if (error) 2473 return error; 2474 /* Quota file not on the same filesystem? */ 2475 if (path->dentry->d_sb != sb) 2476 error = -EXDEV; 2477 else 2478 error = dquot_load_quota_inode(d_inode(path->dentry), type, 2479 format_id, DQUOT_USAGE_ENABLED | 2480 DQUOT_LIMITS_ENABLED); 2481 return error; 2482 } 2483 EXPORT_SYMBOL(dquot_quota_on); 2484 2485 /* 2486 * This function is used when filesystem needs to initialize quotas 2487 * during mount time. 2488 */ 2489 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2490 int format_id, int type) 2491 { 2492 struct dentry *dentry; 2493 int error; 2494 2495 dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2496 if (IS_ERR(dentry)) 2497 return PTR_ERR(dentry); 2498 2499 error = security_quota_on(dentry); 2500 if (!error) 2501 error = dquot_load_quota_inode(d_inode(dentry), type, format_id, 2502 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2503 2504 dput(dentry); 2505 return error; 2506 } 2507 EXPORT_SYMBOL(dquot_quota_on_mount); 2508 2509 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2510 { 2511 int ret; 2512 int type; 2513 struct quota_info *dqopt = sb_dqopt(sb); 2514 2515 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2516 return -ENOSYS; 2517 /* Accounting cannot be turned on while fs is mounted */ 2518 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2519 if (!flags) 2520 return -EINVAL; 2521 for (type = 0; type < MAXQUOTAS; type++) { 2522 if (!(flags & qtype_enforce_flag(type))) 2523 continue; 2524 /* Can't enforce without accounting */ 2525 if (!sb_has_quota_usage_enabled(sb, type)) { 2526 ret = -EINVAL; 2527 goto out_err; 2528 } 2529 if (sb_has_quota_limits_enabled(sb, type)) { 2530 ret = -EBUSY; 2531 goto out_err; 2532 } 2533 spin_lock(&dq_state_lock); 2534 dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2535 spin_unlock(&dq_state_lock); 2536 } 2537 return 0; 2538 out_err: 2539 /* Backout enforcement enablement we already did */ 2540 for (type--; type >= 0; type--) { 2541 if (flags & qtype_enforce_flag(type)) 2542 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2543 } 2544 /* Error code translation for better compatibility with XFS */ 2545 if (ret == -EBUSY) 2546 ret = -EEXIST; 2547 return ret; 2548 } 2549 2550 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2551 { 2552 int ret; 2553 int type; 2554 struct quota_info *dqopt = sb_dqopt(sb); 2555 2556 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2557 return -ENOSYS; 2558 /* 2559 * We don't support turning off accounting via quotactl. In principle 2560 * quota infrastructure can do this but filesystems don't expect 2561 * userspace to be able to do it. 2562 */ 2563 if (flags & 2564 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2565 return -EOPNOTSUPP; 2566 2567 /* Filter out limits not enabled */ 2568 for (type = 0; type < MAXQUOTAS; type++) 2569 if (!sb_has_quota_limits_enabled(sb, type)) 2570 flags &= ~qtype_enforce_flag(type); 2571 /* Nothing left? */ 2572 if (!flags) 2573 return -EEXIST; 2574 for (type = 0; type < MAXQUOTAS; type++) { 2575 if (flags & qtype_enforce_flag(type)) { 2576 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2577 if (ret < 0) 2578 goto out_err; 2579 } 2580 } 2581 return 0; 2582 out_err: 2583 /* Backout enforcement disabling we already did */ 2584 for (type--; type >= 0; type--) { 2585 if (flags & qtype_enforce_flag(type)) { 2586 spin_lock(&dq_state_lock); 2587 dqopt->flags |= 2588 dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2589 spin_unlock(&dq_state_lock); 2590 } 2591 } 2592 return ret; 2593 } 2594 2595 /* Generic routine for getting common part of quota structure */ 2596 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2597 { 2598 struct mem_dqblk *dm = &dquot->dq_dqb; 2599 2600 memset(di, 0, sizeof(*di)); 2601 spin_lock(&dquot->dq_dqb_lock); 2602 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2603 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2604 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2605 di->d_ino_softlimit = dm->dqb_isoftlimit; 2606 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2607 di->d_ino_count = dm->dqb_curinodes; 2608 di->d_spc_timer = dm->dqb_btime; 2609 di->d_ino_timer = dm->dqb_itime; 2610 spin_unlock(&dquot->dq_dqb_lock); 2611 } 2612 2613 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2614 struct qc_dqblk *di) 2615 { 2616 struct dquot *dquot; 2617 2618 dquot = dqget(sb, qid); 2619 if (IS_ERR(dquot)) 2620 return PTR_ERR(dquot); 2621 do_get_dqblk(dquot, di); 2622 dqput(dquot); 2623 2624 return 0; 2625 } 2626 EXPORT_SYMBOL(dquot_get_dqblk); 2627 2628 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2629 struct qc_dqblk *di) 2630 { 2631 struct dquot *dquot; 2632 int err; 2633 2634 if (!sb->dq_op->get_next_id) 2635 return -ENOSYS; 2636 err = sb->dq_op->get_next_id(sb, qid); 2637 if (err < 0) 2638 return err; 2639 dquot = dqget(sb, *qid); 2640 if (IS_ERR(dquot)) 2641 return PTR_ERR(dquot); 2642 do_get_dqblk(dquot, di); 2643 dqput(dquot); 2644 2645 return 0; 2646 } 2647 EXPORT_SYMBOL(dquot_get_next_dqblk); 2648 2649 #define VFS_QC_MASK \ 2650 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2651 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2652 QC_SPC_TIMER | QC_INO_TIMER) 2653 2654 /* Generic routine for setting common part of quota structure */ 2655 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2656 { 2657 struct mem_dqblk *dm = &dquot->dq_dqb; 2658 int check_blim = 0, check_ilim = 0; 2659 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2660 2661 if (di->d_fieldmask & ~VFS_QC_MASK) 2662 return -EINVAL; 2663 2664 if (((di->d_fieldmask & QC_SPC_SOFT) && 2665 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2666 ((di->d_fieldmask & QC_SPC_HARD) && 2667 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2668 ((di->d_fieldmask & QC_INO_SOFT) && 2669 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2670 ((di->d_fieldmask & QC_INO_HARD) && 2671 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2672 return -ERANGE; 2673 2674 spin_lock(&dquot->dq_dqb_lock); 2675 if (di->d_fieldmask & QC_SPACE) { 2676 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2677 check_blim = 1; 2678 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2679 } 2680 2681 if (di->d_fieldmask & QC_SPC_SOFT) 2682 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2683 if (di->d_fieldmask & QC_SPC_HARD) 2684 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2685 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2686 check_blim = 1; 2687 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2688 } 2689 2690 if (di->d_fieldmask & QC_INO_COUNT) { 2691 dm->dqb_curinodes = di->d_ino_count; 2692 check_ilim = 1; 2693 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2694 } 2695 2696 if (di->d_fieldmask & QC_INO_SOFT) 2697 dm->dqb_isoftlimit = di->d_ino_softlimit; 2698 if (di->d_fieldmask & QC_INO_HARD) 2699 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2700 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2701 check_ilim = 1; 2702 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2703 } 2704 2705 if (di->d_fieldmask & QC_SPC_TIMER) { 2706 dm->dqb_btime = di->d_spc_timer; 2707 check_blim = 1; 2708 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2709 } 2710 2711 if (di->d_fieldmask & QC_INO_TIMER) { 2712 dm->dqb_itime = di->d_ino_timer; 2713 check_ilim = 1; 2714 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2715 } 2716 2717 if (check_blim) { 2718 if (!dm->dqb_bsoftlimit || 2719 dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) { 2720 dm->dqb_btime = 0; 2721 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2722 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2723 /* Set grace only if user hasn't provided his own... */ 2724 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2725 } 2726 if (check_ilim) { 2727 if (!dm->dqb_isoftlimit || 2728 dm->dqb_curinodes <= dm->dqb_isoftlimit) { 2729 dm->dqb_itime = 0; 2730 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2731 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2732 /* Set grace only if user hasn't provided his own... */ 2733 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2734 } 2735 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2736 dm->dqb_isoftlimit) 2737 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2738 else 2739 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2740 spin_unlock(&dquot->dq_dqb_lock); 2741 mark_dquot_dirty(dquot); 2742 2743 return 0; 2744 } 2745 2746 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2747 struct qc_dqblk *di) 2748 { 2749 struct dquot *dquot; 2750 int rc; 2751 2752 dquot = dqget(sb, qid); 2753 if (IS_ERR(dquot)) { 2754 rc = PTR_ERR(dquot); 2755 goto out; 2756 } 2757 rc = do_set_dqblk(dquot, di); 2758 dqput(dquot); 2759 out: 2760 return rc; 2761 } 2762 EXPORT_SYMBOL(dquot_set_dqblk); 2763 2764 /* Generic routine for getting common part of quota file information */ 2765 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2766 { 2767 struct mem_dqinfo *mi; 2768 struct qc_type_state *tstate; 2769 struct quota_info *dqopt = sb_dqopt(sb); 2770 int type; 2771 2772 memset(state, 0, sizeof(*state)); 2773 for (type = 0; type < MAXQUOTAS; type++) { 2774 if (!sb_has_quota_active(sb, type)) 2775 continue; 2776 tstate = state->s_state + type; 2777 mi = sb_dqopt(sb)->info + type; 2778 tstate->flags = QCI_ACCT_ENABLED; 2779 spin_lock(&dq_data_lock); 2780 if (mi->dqi_flags & DQF_SYS_FILE) 2781 tstate->flags |= QCI_SYSFILE; 2782 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2783 tstate->flags |= QCI_ROOT_SQUASH; 2784 if (sb_has_quota_limits_enabled(sb, type)) 2785 tstate->flags |= QCI_LIMITS_ENFORCED; 2786 tstate->spc_timelimit = mi->dqi_bgrace; 2787 tstate->ino_timelimit = mi->dqi_igrace; 2788 if (dqopt->files[type]) { 2789 tstate->ino = dqopt->files[type]->i_ino; 2790 tstate->blocks = dqopt->files[type]->i_blocks; 2791 } 2792 tstate->nextents = 1; /* We don't know... */ 2793 spin_unlock(&dq_data_lock); 2794 } 2795 return 0; 2796 } 2797 EXPORT_SYMBOL(dquot_get_state); 2798 2799 /* Generic routine for setting common part of quota file information */ 2800 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2801 { 2802 struct mem_dqinfo *mi; 2803 int err = 0; 2804 2805 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2806 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2807 return -EINVAL; 2808 if (!sb_has_quota_active(sb, type)) 2809 return -ESRCH; 2810 mi = sb_dqopt(sb)->info + type; 2811 if (ii->i_fieldmask & QC_FLAGS) { 2812 if ((ii->i_flags & QCI_ROOT_SQUASH && 2813 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2814 return -EINVAL; 2815 } 2816 spin_lock(&dq_data_lock); 2817 if (ii->i_fieldmask & QC_SPC_TIMER) 2818 mi->dqi_bgrace = ii->i_spc_timelimit; 2819 if (ii->i_fieldmask & QC_INO_TIMER) 2820 mi->dqi_igrace = ii->i_ino_timelimit; 2821 if (ii->i_fieldmask & QC_FLAGS) { 2822 if (ii->i_flags & QCI_ROOT_SQUASH) 2823 mi->dqi_flags |= DQF_ROOT_SQUASH; 2824 else 2825 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2826 } 2827 spin_unlock(&dq_data_lock); 2828 mark_info_dirty(sb, type); 2829 /* Force write to disk */ 2830 sb->dq_op->write_info(sb, type); 2831 return err; 2832 } 2833 EXPORT_SYMBOL(dquot_set_dqinfo); 2834 2835 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2836 .quota_enable = dquot_quota_enable, 2837 .quota_disable = dquot_quota_disable, 2838 .quota_sync = dquot_quota_sync, 2839 .get_state = dquot_get_state, 2840 .set_info = dquot_set_dqinfo, 2841 .get_dqblk = dquot_get_dqblk, 2842 .get_nextdqblk = dquot_get_next_dqblk, 2843 .set_dqblk = dquot_set_dqblk 2844 }; 2845 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2846 2847 static int do_proc_dqstats(struct ctl_table *table, int write, 2848 void *buffer, size_t *lenp, loff_t *ppos) 2849 { 2850 unsigned int type = (unsigned long *)table->data - dqstats.stat; 2851 s64 value = percpu_counter_sum(&dqstats.counter[type]); 2852 2853 /* Filter negative values for non-monotonic counters */ 2854 if (value < 0 && (type == DQST_ALLOC_DQUOTS || 2855 type == DQST_FREE_DQUOTS)) 2856 value = 0; 2857 2858 /* Update global table */ 2859 dqstats.stat[type] = value; 2860 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 2861 } 2862 2863 static struct ctl_table fs_dqstats_table[] = { 2864 { 2865 .procname = "lookups", 2866 .data = &dqstats.stat[DQST_LOOKUPS], 2867 .maxlen = sizeof(unsigned long), 2868 .mode = 0444, 2869 .proc_handler = do_proc_dqstats, 2870 }, 2871 { 2872 .procname = "drops", 2873 .data = &dqstats.stat[DQST_DROPS], 2874 .maxlen = sizeof(unsigned long), 2875 .mode = 0444, 2876 .proc_handler = do_proc_dqstats, 2877 }, 2878 { 2879 .procname = "reads", 2880 .data = &dqstats.stat[DQST_READS], 2881 .maxlen = sizeof(unsigned long), 2882 .mode = 0444, 2883 .proc_handler = do_proc_dqstats, 2884 }, 2885 { 2886 .procname = "writes", 2887 .data = &dqstats.stat[DQST_WRITES], 2888 .maxlen = sizeof(unsigned long), 2889 .mode = 0444, 2890 .proc_handler = do_proc_dqstats, 2891 }, 2892 { 2893 .procname = "cache_hits", 2894 .data = &dqstats.stat[DQST_CACHE_HITS], 2895 .maxlen = sizeof(unsigned long), 2896 .mode = 0444, 2897 .proc_handler = do_proc_dqstats, 2898 }, 2899 { 2900 .procname = "allocated_dquots", 2901 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2902 .maxlen = sizeof(unsigned long), 2903 .mode = 0444, 2904 .proc_handler = do_proc_dqstats, 2905 }, 2906 { 2907 .procname = "free_dquots", 2908 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2909 .maxlen = sizeof(unsigned long), 2910 .mode = 0444, 2911 .proc_handler = do_proc_dqstats, 2912 }, 2913 { 2914 .procname = "syncs", 2915 .data = &dqstats.stat[DQST_SYNCS], 2916 .maxlen = sizeof(unsigned long), 2917 .mode = 0444, 2918 .proc_handler = do_proc_dqstats, 2919 }, 2920 #ifdef CONFIG_PRINT_QUOTA_WARNING 2921 { 2922 .procname = "warnings", 2923 .data = &flag_print_warnings, 2924 .maxlen = sizeof(int), 2925 .mode = 0644, 2926 .proc_handler = proc_dointvec, 2927 }, 2928 #endif 2929 { }, 2930 }; 2931 2932 static struct ctl_table fs_table[] = { 2933 { 2934 .procname = "quota", 2935 .mode = 0555, 2936 .child = fs_dqstats_table, 2937 }, 2938 { }, 2939 }; 2940 2941 static struct ctl_table sys_table[] = { 2942 { 2943 .procname = "fs", 2944 .mode = 0555, 2945 .child = fs_table, 2946 }, 2947 { }, 2948 }; 2949 2950 static int __init dquot_init(void) 2951 { 2952 int i, ret; 2953 unsigned long nr_hash, order; 2954 2955 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2956 2957 register_sysctl_table(sys_table); 2958 2959 dquot_cachep = kmem_cache_create("dquot", 2960 sizeof(struct dquot), sizeof(unsigned long) * 4, 2961 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2962 SLAB_MEM_SPREAD|SLAB_PANIC), 2963 NULL); 2964 2965 order = 0; 2966 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2967 if (!dquot_hash) 2968 panic("Cannot create dquot hash table"); 2969 2970 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2971 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2972 if (ret) 2973 panic("Cannot create dquot stat counters"); 2974 } 2975 2976 /* Find power-of-two hlist_heads which can fit into allocation */ 2977 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2978 dq_hash_bits = ilog2(nr_hash); 2979 2980 nr_hash = 1UL << dq_hash_bits; 2981 dq_hash_mask = nr_hash - 1; 2982 for (i = 0; i < nr_hash; i++) 2983 INIT_HLIST_HEAD(dquot_hash + i); 2984 2985 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2986 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2987 2988 if (register_shrinker(&dqcache_shrinker)) 2989 panic("Cannot register dquot shrinker"); 2990 2991 return 0; 2992 } 2993 fs_initcall(dquot_init); 2994