1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implementation of the diskquota system for the LINUX operating system. QUOTA 4 * is implemented using the BSD system call interface as the means of 5 * communication with the user level. This file contains the generic routines 6 * called by the different filesystems on allocation of an inode or block. 7 * These routines take care of the administration needed to have a consistent 8 * diskquota tracking system. The ideas of both user and group quotas are based 9 * on the Melbourne quota system as used on BSD derived systems. The internal 10 * implementation is based on one of the several variants of the LINUX 11 * inode-subsystem with added complexity of the diskquota system. 12 * 13 * Author: Marco van Wieringen <mvw@planets.elm.net> 14 * 15 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 16 * 17 * Revised list management to avoid races 18 * -- Bill Hawes, <whawes@star.net>, 9/98 19 * 20 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). 21 * As the consequence the locking was moved from dquot_decr_...(), 22 * dquot_incr_...() to calling functions. 23 * invalidate_dquots() now writes modified dquots. 24 * Serialized quota_off() and quota_on() for mount point. 25 * Fixed a few bugs in grow_dquots(). 26 * Fixed deadlock in write_dquot() - we no longer account quotas on 27 * quota files 28 * remove_dquot_ref() moved to inode.c - it now traverses through inodes 29 * add_dquot_ref() restarts after blocking 30 * Added check for bogus uid and fixed check for group in quotactl. 31 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99 32 * 33 * Used struct list_head instead of own list struct 34 * Invalidation of referenced dquots is no longer possible 35 * Improved free_dquots list management 36 * Quota and i_blocks are now updated in one place to avoid races 37 * Warnings are now delayed so we won't block in critical section 38 * Write updated not to require dquot lock 39 * Jan Kara, <jack@suse.cz>, 9/2000 40 * 41 * Added dynamic quota structure allocation 42 * Jan Kara <jack@suse.cz> 12/2000 43 * 44 * Rewritten quota interface. Implemented new quota format and 45 * formats registering. 46 * Jan Kara, <jack@suse.cz>, 2001,2002 47 * 48 * New SMP locking. 49 * Jan Kara, <jack@suse.cz>, 10/2002 50 * 51 * Added journalled quota support, fix lock inversion problems 52 * Jan Kara, <jack@suse.cz>, 2003,2004 53 * 54 * (C) Copyright 1994 - 1997 Marco van Wieringen 55 */ 56 57 #include <linux/errno.h> 58 #include <linux/kernel.h> 59 #include <linux/fs.h> 60 #include <linux/mount.h> 61 #include <linux/mm.h> 62 #include <linux/time.h> 63 #include <linux/types.h> 64 #include <linux/string.h> 65 #include <linux/fcntl.h> 66 #include <linux/stat.h> 67 #include <linux/tty.h> 68 #include <linux/file.h> 69 #include <linux/slab.h> 70 #include <linux/sysctl.h> 71 #include <linux/init.h> 72 #include <linux/module.h> 73 #include <linux/proc_fs.h> 74 #include <linux/security.h> 75 #include <linux/sched.h> 76 #include <linux/cred.h> 77 #include <linux/kmod.h> 78 #include <linux/namei.h> 79 #include <linux/capability.h> 80 #include <linux/quotaops.h> 81 #include "../internal.h" /* ugh */ 82 83 #include <linux/uaccess.h> 84 85 /* 86 * There are five quota SMP locks: 87 * * dq_list_lock protects all lists with quotas and quota formats. 88 * * dquot->dq_dqb_lock protects data from dq_dqb 89 * * inode->i_lock protects inode->i_blocks, i_bytes and also guards 90 * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that 91 * dquot_transfer() can stabilize amount it transfers 92 * * dq_data_lock protects mem_dqinfo structures and modifications of dquot 93 * pointers in the inode 94 * * dq_state_lock protects modifications of quota state (on quotaon and 95 * quotaoff) and readers who care about latest values take it as well. 96 * 97 * The spinlock ordering is hence: 98 * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, 99 * dq_list_lock > dq_state_lock 100 * 101 * Note that some things (eg. sb pointer, type, id) doesn't change during 102 * the life of the dquot structure and so needn't to be protected by a lock 103 * 104 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 105 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 106 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 107 * inode and before dropping dquot references to avoid use of dquots after 108 * they are freed. dq_data_lock is used to serialize the pointer setting and 109 * clearing operations. 110 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 111 * inode is a quota file). Functions adding pointers from inode to dquots have 112 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 113 * have to do all pointer modifications before dropping dq_data_lock. This makes 114 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 115 * then drops all pointers to dquots from an inode. 116 * 117 * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to 118 * memory (or space for it is being allocated) on the first dqget(), when it is 119 * being written out, and when it is being released on the last dqput(). The 120 * allocation and release operations are serialized by the dq_lock and by 121 * checking the use count in dquot_release(). 122 * 123 * Lock ordering (including related VFS locks) is the following: 124 * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem 125 */ 126 127 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 128 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 129 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 130 EXPORT_SYMBOL(dq_data_lock); 131 DEFINE_STATIC_SRCU(dquot_srcu); 132 133 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); 134 135 void __quota_error(struct super_block *sb, const char *func, 136 const char *fmt, ...) 137 { 138 if (printk_ratelimit()) { 139 va_list args; 140 struct va_format vaf; 141 142 va_start(args, fmt); 143 144 vaf.fmt = fmt; 145 vaf.va = &args; 146 147 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 148 sb->s_id, func, &vaf); 149 150 va_end(args); 151 } 152 } 153 EXPORT_SYMBOL(__quota_error); 154 155 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 156 static char *quotatypes[] = INITQFNAMES; 157 #endif 158 static struct quota_format_type *quota_formats; /* List of registered formats */ 159 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 160 161 /* SLAB cache for dquot structures */ 162 static struct kmem_cache *dquot_cachep; 163 164 int register_quota_format(struct quota_format_type *fmt) 165 { 166 spin_lock(&dq_list_lock); 167 fmt->qf_next = quota_formats; 168 quota_formats = fmt; 169 spin_unlock(&dq_list_lock); 170 return 0; 171 } 172 EXPORT_SYMBOL(register_quota_format); 173 174 void unregister_quota_format(struct quota_format_type *fmt) 175 { 176 struct quota_format_type **actqf; 177 178 spin_lock(&dq_list_lock); 179 for (actqf = "a_formats; *actqf && *actqf != fmt; 180 actqf = &(*actqf)->qf_next) 181 ; 182 if (*actqf) 183 *actqf = (*actqf)->qf_next; 184 spin_unlock(&dq_list_lock); 185 } 186 EXPORT_SYMBOL(unregister_quota_format); 187 188 static struct quota_format_type *find_quota_format(int id) 189 { 190 struct quota_format_type *actqf; 191 192 spin_lock(&dq_list_lock); 193 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 194 actqf = actqf->qf_next) 195 ; 196 if (!actqf || !try_module_get(actqf->qf_owner)) { 197 int qm; 198 199 spin_unlock(&dq_list_lock); 200 201 for (qm = 0; module_names[qm].qm_fmt_id && 202 module_names[qm].qm_fmt_id != id; qm++) 203 ; 204 if (!module_names[qm].qm_fmt_id || 205 request_module(module_names[qm].qm_mod_name)) 206 return NULL; 207 208 spin_lock(&dq_list_lock); 209 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 210 actqf = actqf->qf_next) 211 ; 212 if (actqf && !try_module_get(actqf->qf_owner)) 213 actqf = NULL; 214 } 215 spin_unlock(&dq_list_lock); 216 return actqf; 217 } 218 219 static void put_quota_format(struct quota_format_type *fmt) 220 { 221 module_put(fmt->qf_owner); 222 } 223 224 /* 225 * Dquot List Management: 226 * The quota code uses three lists for dquot management: the inuse_list, 227 * free_dquots, and dquot_hash[] array. A single dquot structure may be 228 * on all three lists, depending on its current state. 229 * 230 * All dquots are placed to the end of inuse_list when first created, and this 231 * list is used for invalidate operation, which must look at every dquot. 232 * 233 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 234 * and this list is searched whenever we need an available dquot. Dquots are 235 * removed from the list as soon as they are used again, and 236 * dqstats.free_dquots gives the number of dquots on the list. When 237 * dquot is invalidated it's completely released from memory. 238 * 239 * Dquots with a specific identity (device, type and id) are placed on 240 * one of the dquot_hash[] hash chains. The provides an efficient search 241 * mechanism to locate a specific dquot. 242 */ 243 244 static LIST_HEAD(inuse_list); 245 static LIST_HEAD(free_dquots); 246 static unsigned int dq_hash_bits, dq_hash_mask; 247 static struct hlist_head *dquot_hash; 248 249 struct dqstats dqstats; 250 EXPORT_SYMBOL(dqstats); 251 252 static qsize_t inode_get_rsv_space(struct inode *inode); 253 static qsize_t __inode_get_rsv_space(struct inode *inode); 254 static int __dquot_initialize(struct inode *inode, int type); 255 256 static inline unsigned int 257 hashfn(const struct super_block *sb, struct kqid qid) 258 { 259 unsigned int id = from_kqid(&init_user_ns, qid); 260 int type = qid.type; 261 unsigned long tmp; 262 263 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 264 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 265 } 266 267 /* 268 * Following list functions expect dq_list_lock to be held 269 */ 270 static inline void insert_dquot_hash(struct dquot *dquot) 271 { 272 struct hlist_head *head; 273 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 274 hlist_add_head(&dquot->dq_hash, head); 275 } 276 277 static inline void remove_dquot_hash(struct dquot *dquot) 278 { 279 hlist_del_init(&dquot->dq_hash); 280 } 281 282 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 283 struct kqid qid) 284 { 285 struct hlist_node *node; 286 struct dquot *dquot; 287 288 hlist_for_each (node, dquot_hash+hashent) { 289 dquot = hlist_entry(node, struct dquot, dq_hash); 290 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 291 return dquot; 292 } 293 return NULL; 294 } 295 296 /* Add a dquot to the tail of the free list */ 297 static inline void put_dquot_last(struct dquot *dquot) 298 { 299 list_add_tail(&dquot->dq_free, &free_dquots); 300 dqstats_inc(DQST_FREE_DQUOTS); 301 } 302 303 static inline void remove_free_dquot(struct dquot *dquot) 304 { 305 if (list_empty(&dquot->dq_free)) 306 return; 307 list_del_init(&dquot->dq_free); 308 dqstats_dec(DQST_FREE_DQUOTS); 309 } 310 311 static inline void put_inuse(struct dquot *dquot) 312 { 313 /* We add to the back of inuse list so we don't have to restart 314 * when traversing this list and we block */ 315 list_add_tail(&dquot->dq_inuse, &inuse_list); 316 dqstats_inc(DQST_ALLOC_DQUOTS); 317 } 318 319 static inline void remove_inuse(struct dquot *dquot) 320 { 321 dqstats_dec(DQST_ALLOC_DQUOTS); 322 list_del(&dquot->dq_inuse); 323 } 324 /* 325 * End of list functions needing dq_list_lock 326 */ 327 328 static void wait_on_dquot(struct dquot *dquot) 329 { 330 mutex_lock(&dquot->dq_lock); 331 mutex_unlock(&dquot->dq_lock); 332 } 333 334 static inline int dquot_dirty(struct dquot *dquot) 335 { 336 return test_bit(DQ_MOD_B, &dquot->dq_flags); 337 } 338 339 static inline int mark_dquot_dirty(struct dquot *dquot) 340 { 341 return dquot->dq_sb->dq_op->mark_dirty(dquot); 342 } 343 344 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 345 int dquot_mark_dquot_dirty(struct dquot *dquot) 346 { 347 int ret = 1; 348 349 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 350 return 0; 351 352 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 353 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 354 355 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 356 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 357 return 1; 358 359 spin_lock(&dq_list_lock); 360 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 361 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 362 info[dquot->dq_id.type].dqi_dirty_list); 363 ret = 0; 364 } 365 spin_unlock(&dq_list_lock); 366 return ret; 367 } 368 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 369 370 /* Dirtify all the dquots - this can block when journalling */ 371 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 372 { 373 int ret, err, cnt; 374 375 ret = err = 0; 376 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 377 if (dquot[cnt]) 378 /* Even in case of error we have to continue */ 379 ret = mark_dquot_dirty(dquot[cnt]); 380 if (!err) 381 err = ret; 382 } 383 return err; 384 } 385 386 static inline void dqput_all(struct dquot **dquot) 387 { 388 unsigned int cnt; 389 390 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 391 dqput(dquot[cnt]); 392 } 393 394 static inline int clear_dquot_dirty(struct dquot *dquot) 395 { 396 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 397 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 398 399 spin_lock(&dq_list_lock); 400 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 401 spin_unlock(&dq_list_lock); 402 return 0; 403 } 404 list_del_init(&dquot->dq_dirty); 405 spin_unlock(&dq_list_lock); 406 return 1; 407 } 408 409 void mark_info_dirty(struct super_block *sb, int type) 410 { 411 spin_lock(&dq_data_lock); 412 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 413 spin_unlock(&dq_data_lock); 414 } 415 EXPORT_SYMBOL(mark_info_dirty); 416 417 /* 418 * Read dquot from disk and alloc space for it 419 */ 420 421 int dquot_acquire(struct dquot *dquot) 422 { 423 int ret = 0, ret2 = 0; 424 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 425 426 mutex_lock(&dquot->dq_lock); 427 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { 428 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 429 if (ret < 0) 430 goto out_iolock; 431 } 432 /* Make sure flags update is visible after dquot has been filled */ 433 smp_mb__before_atomic(); 434 set_bit(DQ_READ_B, &dquot->dq_flags); 435 /* Instantiate dquot if needed */ 436 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 437 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 438 /* Write the info if needed */ 439 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 440 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 441 dquot->dq_sb, dquot->dq_id.type); 442 } 443 if (ret < 0) 444 goto out_iolock; 445 if (ret2 < 0) { 446 ret = ret2; 447 goto out_iolock; 448 } 449 } 450 /* 451 * Make sure flags update is visible after on-disk struct has been 452 * allocated. Paired with smp_rmb() in dqget(). 453 */ 454 smp_mb__before_atomic(); 455 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 456 out_iolock: 457 mutex_unlock(&dquot->dq_lock); 458 return ret; 459 } 460 EXPORT_SYMBOL(dquot_acquire); 461 462 /* 463 * Write dquot to disk 464 */ 465 int dquot_commit(struct dquot *dquot) 466 { 467 int ret = 0; 468 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 469 470 mutex_lock(&dquot->dq_lock); 471 if (!clear_dquot_dirty(dquot)) 472 goto out_lock; 473 /* Inactive dquot can be only if there was error during read/init 474 * => we have better not writing it */ 475 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 476 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 477 else 478 ret = -EIO; 479 out_lock: 480 mutex_unlock(&dquot->dq_lock); 481 return ret; 482 } 483 EXPORT_SYMBOL(dquot_commit); 484 485 /* 486 * Release dquot 487 */ 488 int dquot_release(struct dquot *dquot) 489 { 490 int ret = 0, ret2 = 0; 491 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 492 493 mutex_lock(&dquot->dq_lock); 494 /* Check whether we are not racing with some other dqget() */ 495 if (atomic_read(&dquot->dq_count) > 1) 496 goto out_dqlock; 497 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 498 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 499 /* Write the info */ 500 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 501 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 502 dquot->dq_sb, dquot->dq_id.type); 503 } 504 if (ret >= 0) 505 ret = ret2; 506 } 507 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 508 out_dqlock: 509 mutex_unlock(&dquot->dq_lock); 510 return ret; 511 } 512 EXPORT_SYMBOL(dquot_release); 513 514 void dquot_destroy(struct dquot *dquot) 515 { 516 kmem_cache_free(dquot_cachep, dquot); 517 } 518 EXPORT_SYMBOL(dquot_destroy); 519 520 static inline void do_destroy_dquot(struct dquot *dquot) 521 { 522 dquot->dq_sb->dq_op->destroy_dquot(dquot); 523 } 524 525 /* Invalidate all dquots on the list. Note that this function is called after 526 * quota is disabled and pointers from inodes removed so there cannot be new 527 * quota users. There can still be some users of quotas due to inodes being 528 * just deleted or pruned by prune_icache() (those are not attached to any 529 * list) or parallel quotactl call. We have to wait for such users. 530 */ 531 static void invalidate_dquots(struct super_block *sb, int type) 532 { 533 struct dquot *dquot, *tmp; 534 535 restart: 536 spin_lock(&dq_list_lock); 537 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 538 if (dquot->dq_sb != sb) 539 continue; 540 if (dquot->dq_id.type != type) 541 continue; 542 /* Wait for dquot users */ 543 if (atomic_read(&dquot->dq_count)) { 544 dqgrab(dquot); 545 spin_unlock(&dq_list_lock); 546 /* 547 * Once dqput() wakes us up, we know it's time to free 548 * the dquot. 549 * IMPORTANT: we rely on the fact that there is always 550 * at most one process waiting for dquot to free. 551 * Otherwise dq_count would be > 1 and we would never 552 * wake up. 553 */ 554 wait_event(dquot_ref_wq, 555 atomic_read(&dquot->dq_count) == 1); 556 dqput(dquot); 557 /* At this moment dquot() need not exist (it could be 558 * reclaimed by prune_dqcache(). Hence we must 559 * restart. */ 560 goto restart; 561 } 562 /* 563 * Quota now has no users and it has been written on last 564 * dqput() 565 */ 566 remove_dquot_hash(dquot); 567 remove_free_dquot(dquot); 568 remove_inuse(dquot); 569 do_destroy_dquot(dquot); 570 } 571 spin_unlock(&dq_list_lock); 572 } 573 574 /* Call callback for every active dquot on given filesystem */ 575 int dquot_scan_active(struct super_block *sb, 576 int (*fn)(struct dquot *dquot, unsigned long priv), 577 unsigned long priv) 578 { 579 struct dquot *dquot, *old_dquot = NULL; 580 int ret = 0; 581 582 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 583 584 spin_lock(&dq_list_lock); 585 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 586 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 587 continue; 588 if (dquot->dq_sb != sb) 589 continue; 590 /* Now we have active dquot so we can just increase use count */ 591 atomic_inc(&dquot->dq_count); 592 spin_unlock(&dq_list_lock); 593 dqstats_inc(DQST_LOOKUPS); 594 dqput(old_dquot); 595 old_dquot = dquot; 596 /* 597 * ->release_dquot() can be racing with us. Our reference 598 * protects us from new calls to it so just wait for any 599 * outstanding call and recheck the DQ_ACTIVE_B after that. 600 */ 601 wait_on_dquot(dquot); 602 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 603 ret = fn(dquot, priv); 604 if (ret < 0) 605 goto out; 606 } 607 spin_lock(&dq_list_lock); 608 /* We are safe to continue now because our dquot could not 609 * be moved out of the inuse list while we hold the reference */ 610 } 611 spin_unlock(&dq_list_lock); 612 out: 613 dqput(old_dquot); 614 return ret; 615 } 616 EXPORT_SYMBOL(dquot_scan_active); 617 618 /* Write all dquot structures to quota files */ 619 int dquot_writeback_dquots(struct super_block *sb, int type) 620 { 621 struct list_head *dirty; 622 struct dquot *dquot; 623 struct quota_info *dqopt = sb_dqopt(sb); 624 int cnt; 625 int err, ret = 0; 626 627 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 628 629 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 630 if (type != -1 && cnt != type) 631 continue; 632 if (!sb_has_quota_active(sb, cnt)) 633 continue; 634 spin_lock(&dq_list_lock); 635 dirty = &dqopt->info[cnt].dqi_dirty_list; 636 while (!list_empty(dirty)) { 637 dquot = list_first_entry(dirty, struct dquot, 638 dq_dirty); 639 640 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 641 642 /* Now we have active dquot from which someone is 643 * holding reference so we can safely just increase 644 * use count */ 645 dqgrab(dquot); 646 spin_unlock(&dq_list_lock); 647 dqstats_inc(DQST_LOOKUPS); 648 err = sb->dq_op->write_dquot(dquot); 649 if (err) { 650 /* 651 * Clear dirty bit anyway to avoid infinite 652 * loop here. 653 */ 654 clear_dquot_dirty(dquot); 655 if (!ret) 656 ret = err; 657 } 658 dqput(dquot); 659 spin_lock(&dq_list_lock); 660 } 661 spin_unlock(&dq_list_lock); 662 } 663 664 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 665 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 666 && info_dirty(&dqopt->info[cnt])) 667 sb->dq_op->write_info(sb, cnt); 668 dqstats_inc(DQST_SYNCS); 669 670 return ret; 671 } 672 EXPORT_SYMBOL(dquot_writeback_dquots); 673 674 /* Write all dquot structures to disk and make them visible from userspace */ 675 int dquot_quota_sync(struct super_block *sb, int type) 676 { 677 struct quota_info *dqopt = sb_dqopt(sb); 678 int cnt; 679 int ret; 680 681 ret = dquot_writeback_dquots(sb, type); 682 if (ret) 683 return ret; 684 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 685 return 0; 686 687 /* This is not very clever (and fast) but currently I don't know about 688 * any other simple way of getting quota data to disk and we must get 689 * them there for userspace to be visible... */ 690 if (sb->s_op->sync_fs) 691 sb->s_op->sync_fs(sb, 1); 692 sync_blockdev(sb->s_bdev); 693 694 /* 695 * Now when everything is written we can discard the pagecache so 696 * that userspace sees the changes. 697 */ 698 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 699 if (type != -1 && cnt != type) 700 continue; 701 if (!sb_has_quota_active(sb, cnt)) 702 continue; 703 inode_lock(dqopt->files[cnt]); 704 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 705 inode_unlock(dqopt->files[cnt]); 706 } 707 708 return 0; 709 } 710 EXPORT_SYMBOL(dquot_quota_sync); 711 712 static unsigned long 713 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 714 { 715 struct dquot *dquot; 716 unsigned long freed = 0; 717 718 spin_lock(&dq_list_lock); 719 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 720 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 721 remove_dquot_hash(dquot); 722 remove_free_dquot(dquot); 723 remove_inuse(dquot); 724 do_destroy_dquot(dquot); 725 sc->nr_to_scan--; 726 freed++; 727 } 728 spin_unlock(&dq_list_lock); 729 return freed; 730 } 731 732 static unsigned long 733 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 734 { 735 return vfs_pressure_ratio( 736 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 737 } 738 739 static struct shrinker dqcache_shrinker = { 740 .count_objects = dqcache_shrink_count, 741 .scan_objects = dqcache_shrink_scan, 742 .seeks = DEFAULT_SEEKS, 743 }; 744 745 /* 746 * Put reference to dquot 747 */ 748 void dqput(struct dquot *dquot) 749 { 750 int ret; 751 752 if (!dquot) 753 return; 754 #ifdef CONFIG_QUOTA_DEBUG 755 if (!atomic_read(&dquot->dq_count)) { 756 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 757 quotatypes[dquot->dq_id.type], 758 from_kqid(&init_user_ns, dquot->dq_id)); 759 BUG(); 760 } 761 #endif 762 dqstats_inc(DQST_DROPS); 763 we_slept: 764 spin_lock(&dq_list_lock); 765 if (atomic_read(&dquot->dq_count) > 1) { 766 /* We have more than one user... nothing to do */ 767 atomic_dec(&dquot->dq_count); 768 /* Releasing dquot during quotaoff phase? */ 769 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 770 atomic_read(&dquot->dq_count) == 1) 771 wake_up(&dquot_ref_wq); 772 spin_unlock(&dq_list_lock); 773 return; 774 } 775 /* Need to release dquot? */ 776 if (dquot_dirty(dquot)) { 777 spin_unlock(&dq_list_lock); 778 /* Commit dquot before releasing */ 779 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 780 if (ret < 0) { 781 quota_error(dquot->dq_sb, "Can't write quota structure" 782 " (error %d). Quota may get out of sync!", 783 ret); 784 /* 785 * We clear dirty bit anyway, so that we avoid 786 * infinite loop here 787 */ 788 clear_dquot_dirty(dquot); 789 } 790 goto we_slept; 791 } 792 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 793 spin_unlock(&dq_list_lock); 794 dquot->dq_sb->dq_op->release_dquot(dquot); 795 goto we_slept; 796 } 797 atomic_dec(&dquot->dq_count); 798 #ifdef CONFIG_QUOTA_DEBUG 799 /* sanity check */ 800 BUG_ON(!list_empty(&dquot->dq_free)); 801 #endif 802 put_dquot_last(dquot); 803 spin_unlock(&dq_list_lock); 804 } 805 EXPORT_SYMBOL(dqput); 806 807 struct dquot *dquot_alloc(struct super_block *sb, int type) 808 { 809 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 810 } 811 EXPORT_SYMBOL(dquot_alloc); 812 813 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 814 { 815 struct dquot *dquot; 816 817 dquot = sb->dq_op->alloc_dquot(sb, type); 818 if(!dquot) 819 return NULL; 820 821 mutex_init(&dquot->dq_lock); 822 INIT_LIST_HEAD(&dquot->dq_free); 823 INIT_LIST_HEAD(&dquot->dq_inuse); 824 INIT_HLIST_NODE(&dquot->dq_hash); 825 INIT_LIST_HEAD(&dquot->dq_dirty); 826 dquot->dq_sb = sb; 827 dquot->dq_id = make_kqid_invalid(type); 828 atomic_set(&dquot->dq_count, 1); 829 spin_lock_init(&dquot->dq_dqb_lock); 830 831 return dquot; 832 } 833 834 /* 835 * Get reference to dquot 836 * 837 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 838 * destroying our dquot by: 839 * a) checking for quota flags under dq_list_lock and 840 * b) getting a reference to dquot before we release dq_list_lock 841 */ 842 struct dquot *dqget(struct super_block *sb, struct kqid qid) 843 { 844 unsigned int hashent = hashfn(sb, qid); 845 struct dquot *dquot, *empty = NULL; 846 847 if (!qid_has_mapping(sb->s_user_ns, qid)) 848 return ERR_PTR(-EINVAL); 849 850 if (!sb_has_quota_active(sb, qid.type)) 851 return ERR_PTR(-ESRCH); 852 we_slept: 853 spin_lock(&dq_list_lock); 854 spin_lock(&dq_state_lock); 855 if (!sb_has_quota_active(sb, qid.type)) { 856 spin_unlock(&dq_state_lock); 857 spin_unlock(&dq_list_lock); 858 dquot = ERR_PTR(-ESRCH); 859 goto out; 860 } 861 spin_unlock(&dq_state_lock); 862 863 dquot = find_dquot(hashent, sb, qid); 864 if (!dquot) { 865 if (!empty) { 866 spin_unlock(&dq_list_lock); 867 empty = get_empty_dquot(sb, qid.type); 868 if (!empty) 869 schedule(); /* Try to wait for a moment... */ 870 goto we_slept; 871 } 872 dquot = empty; 873 empty = NULL; 874 dquot->dq_id = qid; 875 /* all dquots go on the inuse_list */ 876 put_inuse(dquot); 877 /* hash it first so it can be found */ 878 insert_dquot_hash(dquot); 879 spin_unlock(&dq_list_lock); 880 dqstats_inc(DQST_LOOKUPS); 881 } else { 882 if (!atomic_read(&dquot->dq_count)) 883 remove_free_dquot(dquot); 884 atomic_inc(&dquot->dq_count); 885 spin_unlock(&dq_list_lock); 886 dqstats_inc(DQST_CACHE_HITS); 887 dqstats_inc(DQST_LOOKUPS); 888 } 889 /* Wait for dq_lock - after this we know that either dquot_release() is 890 * already finished or it will be canceled due to dq_count > 1 test */ 891 wait_on_dquot(dquot); 892 /* Read the dquot / allocate space in quota file */ 893 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 894 int err; 895 896 err = sb->dq_op->acquire_dquot(dquot); 897 if (err < 0) { 898 dqput(dquot); 899 dquot = ERR_PTR(err); 900 goto out; 901 } 902 } 903 /* 904 * Make sure following reads see filled structure - paired with 905 * smp_mb__before_atomic() in dquot_acquire(). 906 */ 907 smp_rmb(); 908 #ifdef CONFIG_QUOTA_DEBUG 909 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 910 #endif 911 out: 912 if (empty) 913 do_destroy_dquot(empty); 914 915 return dquot; 916 } 917 EXPORT_SYMBOL(dqget); 918 919 static inline struct dquot **i_dquot(struct inode *inode) 920 { 921 return inode->i_sb->s_op->get_dquots(inode); 922 } 923 924 static int dqinit_needed(struct inode *inode, int type) 925 { 926 struct dquot * const *dquots; 927 int cnt; 928 929 if (IS_NOQUOTA(inode)) 930 return 0; 931 932 dquots = i_dquot(inode); 933 if (type != -1) 934 return !dquots[type]; 935 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 936 if (!dquots[cnt]) 937 return 1; 938 return 0; 939 } 940 941 /* This routine is guarded by s_umount semaphore */ 942 static int add_dquot_ref(struct super_block *sb, int type) 943 { 944 struct inode *inode, *old_inode = NULL; 945 #ifdef CONFIG_QUOTA_DEBUG 946 int reserved = 0; 947 #endif 948 int err = 0; 949 950 spin_lock(&sb->s_inode_list_lock); 951 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 952 spin_lock(&inode->i_lock); 953 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 954 !atomic_read(&inode->i_writecount) || 955 !dqinit_needed(inode, type)) { 956 spin_unlock(&inode->i_lock); 957 continue; 958 } 959 __iget(inode); 960 spin_unlock(&inode->i_lock); 961 spin_unlock(&sb->s_inode_list_lock); 962 963 #ifdef CONFIG_QUOTA_DEBUG 964 if (unlikely(inode_get_rsv_space(inode) > 0)) 965 reserved = 1; 966 #endif 967 iput(old_inode); 968 err = __dquot_initialize(inode, type); 969 if (err) { 970 iput(inode); 971 goto out; 972 } 973 974 /* 975 * We hold a reference to 'inode' so it couldn't have been 976 * removed from s_inodes list while we dropped the 977 * s_inode_list_lock. We cannot iput the inode now as we can be 978 * holding the last reference and we cannot iput it under 979 * s_inode_list_lock. So we keep the reference and iput it 980 * later. 981 */ 982 old_inode = inode; 983 spin_lock(&sb->s_inode_list_lock); 984 } 985 spin_unlock(&sb->s_inode_list_lock); 986 iput(old_inode); 987 out: 988 #ifdef CONFIG_QUOTA_DEBUG 989 if (reserved) { 990 quota_error(sb, "Writes happened before quota was turned on " 991 "thus quota information is probably inconsistent. " 992 "Please run quotacheck(8)"); 993 } 994 #endif 995 return err; 996 } 997 998 /* 999 * Remove references to dquots from inode and add dquot to list for freeing 1000 * if we have the last reference to dquot 1001 */ 1002 static void remove_inode_dquot_ref(struct inode *inode, int type, 1003 struct list_head *tofree_head) 1004 { 1005 struct dquot **dquots = i_dquot(inode); 1006 struct dquot *dquot = dquots[type]; 1007 1008 if (!dquot) 1009 return; 1010 1011 dquots[type] = NULL; 1012 if (list_empty(&dquot->dq_free)) { 1013 /* 1014 * The inode still has reference to dquot so it can't be in the 1015 * free list 1016 */ 1017 spin_lock(&dq_list_lock); 1018 list_add(&dquot->dq_free, tofree_head); 1019 spin_unlock(&dq_list_lock); 1020 } else { 1021 /* 1022 * Dquot is already in a list to put so we won't drop the last 1023 * reference here. 1024 */ 1025 dqput(dquot); 1026 } 1027 } 1028 1029 /* 1030 * Free list of dquots 1031 * Dquots are removed from inodes and no new references can be got so we are 1032 * the only ones holding reference 1033 */ 1034 static void put_dquot_list(struct list_head *tofree_head) 1035 { 1036 struct list_head *act_head; 1037 struct dquot *dquot; 1038 1039 act_head = tofree_head->next; 1040 while (act_head != tofree_head) { 1041 dquot = list_entry(act_head, struct dquot, dq_free); 1042 act_head = act_head->next; 1043 /* Remove dquot from the list so we won't have problems... */ 1044 list_del_init(&dquot->dq_free); 1045 dqput(dquot); 1046 } 1047 } 1048 1049 static void remove_dquot_ref(struct super_block *sb, int type, 1050 struct list_head *tofree_head) 1051 { 1052 struct inode *inode; 1053 #ifdef CONFIG_QUOTA_DEBUG 1054 int reserved = 0; 1055 #endif 1056 1057 spin_lock(&sb->s_inode_list_lock); 1058 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1059 /* 1060 * We have to scan also I_NEW inodes because they can already 1061 * have quota pointer initialized. Luckily, we need to touch 1062 * only quota pointers and these have separate locking 1063 * (dq_data_lock). 1064 */ 1065 spin_lock(&dq_data_lock); 1066 if (!IS_NOQUOTA(inode)) { 1067 #ifdef CONFIG_QUOTA_DEBUG 1068 if (unlikely(inode_get_rsv_space(inode) > 0)) 1069 reserved = 1; 1070 #endif 1071 remove_inode_dquot_ref(inode, type, tofree_head); 1072 } 1073 spin_unlock(&dq_data_lock); 1074 } 1075 spin_unlock(&sb->s_inode_list_lock); 1076 #ifdef CONFIG_QUOTA_DEBUG 1077 if (reserved) { 1078 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1079 " was disabled thus quota information is probably " 1080 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1081 } 1082 #endif 1083 } 1084 1085 /* Gather all references from inodes and drop them */ 1086 static void drop_dquot_ref(struct super_block *sb, int type) 1087 { 1088 LIST_HEAD(tofree_head); 1089 1090 if (sb->dq_op) { 1091 remove_dquot_ref(sb, type, &tofree_head); 1092 synchronize_srcu(&dquot_srcu); 1093 put_dquot_list(&tofree_head); 1094 } 1095 } 1096 1097 static inline 1098 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1099 { 1100 if (dquot->dq_dqb.dqb_rsvspace >= number) 1101 dquot->dq_dqb.dqb_rsvspace -= number; 1102 else { 1103 WARN_ON_ONCE(1); 1104 dquot->dq_dqb.dqb_rsvspace = 0; 1105 } 1106 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1107 dquot->dq_dqb.dqb_bsoftlimit) 1108 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1109 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1110 } 1111 1112 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1113 { 1114 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1115 dquot->dq_dqb.dqb_curinodes >= number) 1116 dquot->dq_dqb.dqb_curinodes -= number; 1117 else 1118 dquot->dq_dqb.dqb_curinodes = 0; 1119 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1120 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1121 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1122 } 1123 1124 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1125 { 1126 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1127 dquot->dq_dqb.dqb_curspace >= number) 1128 dquot->dq_dqb.dqb_curspace -= number; 1129 else 1130 dquot->dq_dqb.dqb_curspace = 0; 1131 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1132 dquot->dq_dqb.dqb_bsoftlimit) 1133 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1134 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1135 } 1136 1137 struct dquot_warn { 1138 struct super_block *w_sb; 1139 struct kqid w_dq_id; 1140 short w_type; 1141 }; 1142 1143 static int warning_issued(struct dquot *dquot, const int warntype) 1144 { 1145 int flag = (warntype == QUOTA_NL_BHARDWARN || 1146 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1147 ((warntype == QUOTA_NL_IHARDWARN || 1148 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1149 1150 if (!flag) 1151 return 0; 1152 return test_and_set_bit(flag, &dquot->dq_flags); 1153 } 1154 1155 #ifdef CONFIG_PRINT_QUOTA_WARNING 1156 static int flag_print_warnings = 1; 1157 1158 static int need_print_warning(struct dquot_warn *warn) 1159 { 1160 if (!flag_print_warnings) 1161 return 0; 1162 1163 switch (warn->w_dq_id.type) { 1164 case USRQUOTA: 1165 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1166 case GRPQUOTA: 1167 return in_group_p(warn->w_dq_id.gid); 1168 case PRJQUOTA: 1169 return 1; 1170 } 1171 return 0; 1172 } 1173 1174 /* Print warning to user which exceeded quota */ 1175 static void print_warning(struct dquot_warn *warn) 1176 { 1177 char *msg = NULL; 1178 struct tty_struct *tty; 1179 int warntype = warn->w_type; 1180 1181 if (warntype == QUOTA_NL_IHARDBELOW || 1182 warntype == QUOTA_NL_ISOFTBELOW || 1183 warntype == QUOTA_NL_BHARDBELOW || 1184 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1185 return; 1186 1187 tty = get_current_tty(); 1188 if (!tty) 1189 return; 1190 tty_write_message(tty, warn->w_sb->s_id); 1191 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1192 tty_write_message(tty, ": warning, "); 1193 else 1194 tty_write_message(tty, ": write failed, "); 1195 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1196 switch (warntype) { 1197 case QUOTA_NL_IHARDWARN: 1198 msg = " file limit reached.\r\n"; 1199 break; 1200 case QUOTA_NL_ISOFTLONGWARN: 1201 msg = " file quota exceeded too long.\r\n"; 1202 break; 1203 case QUOTA_NL_ISOFTWARN: 1204 msg = " file quota exceeded.\r\n"; 1205 break; 1206 case QUOTA_NL_BHARDWARN: 1207 msg = " block limit reached.\r\n"; 1208 break; 1209 case QUOTA_NL_BSOFTLONGWARN: 1210 msg = " block quota exceeded too long.\r\n"; 1211 break; 1212 case QUOTA_NL_BSOFTWARN: 1213 msg = " block quota exceeded.\r\n"; 1214 break; 1215 } 1216 tty_write_message(tty, msg); 1217 tty_kref_put(tty); 1218 } 1219 #endif 1220 1221 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1222 int warntype) 1223 { 1224 if (warning_issued(dquot, warntype)) 1225 return; 1226 warn->w_type = warntype; 1227 warn->w_sb = dquot->dq_sb; 1228 warn->w_dq_id = dquot->dq_id; 1229 } 1230 1231 /* 1232 * Write warnings to the console and send warning messages over netlink. 1233 * 1234 * Note that this function can call into tty and networking code. 1235 */ 1236 static void flush_warnings(struct dquot_warn *warn) 1237 { 1238 int i; 1239 1240 for (i = 0; i < MAXQUOTAS; i++) { 1241 if (warn[i].w_type == QUOTA_NL_NOWARN) 1242 continue; 1243 #ifdef CONFIG_PRINT_QUOTA_WARNING 1244 print_warning(&warn[i]); 1245 #endif 1246 quota_send_warning(warn[i].w_dq_id, 1247 warn[i].w_sb->s_dev, warn[i].w_type); 1248 } 1249 } 1250 1251 static int ignore_hardlimit(struct dquot *dquot) 1252 { 1253 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1254 1255 return capable(CAP_SYS_RESOURCE) && 1256 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1257 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1258 } 1259 1260 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1261 struct dquot_warn *warn) 1262 { 1263 qsize_t newinodes; 1264 int ret = 0; 1265 1266 spin_lock(&dquot->dq_dqb_lock); 1267 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1268 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1269 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1270 goto add; 1271 1272 if (dquot->dq_dqb.dqb_ihardlimit && 1273 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1274 !ignore_hardlimit(dquot)) { 1275 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1276 ret = -EDQUOT; 1277 goto out; 1278 } 1279 1280 if (dquot->dq_dqb.dqb_isoftlimit && 1281 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1282 dquot->dq_dqb.dqb_itime && 1283 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1284 !ignore_hardlimit(dquot)) { 1285 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1286 ret = -EDQUOT; 1287 goto out; 1288 } 1289 1290 if (dquot->dq_dqb.dqb_isoftlimit && 1291 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1292 dquot->dq_dqb.dqb_itime == 0) { 1293 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1294 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1295 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1296 } 1297 add: 1298 dquot->dq_dqb.dqb_curinodes = newinodes; 1299 1300 out: 1301 spin_unlock(&dquot->dq_dqb_lock); 1302 return ret; 1303 } 1304 1305 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1306 qsize_t rsv_space, unsigned int flags, 1307 struct dquot_warn *warn) 1308 { 1309 qsize_t tspace; 1310 struct super_block *sb = dquot->dq_sb; 1311 int ret = 0; 1312 1313 spin_lock(&dquot->dq_dqb_lock); 1314 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1315 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1316 goto finish; 1317 1318 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1319 + space + rsv_space; 1320 1321 if (dquot->dq_dqb.dqb_bhardlimit && 1322 tspace > dquot->dq_dqb.dqb_bhardlimit && 1323 !ignore_hardlimit(dquot)) { 1324 if (flags & DQUOT_SPACE_WARN) 1325 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1326 ret = -EDQUOT; 1327 goto finish; 1328 } 1329 1330 if (dquot->dq_dqb.dqb_bsoftlimit && 1331 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1332 dquot->dq_dqb.dqb_btime && 1333 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1334 !ignore_hardlimit(dquot)) { 1335 if (flags & DQUOT_SPACE_WARN) 1336 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1337 ret = -EDQUOT; 1338 goto finish; 1339 } 1340 1341 if (dquot->dq_dqb.dqb_bsoftlimit && 1342 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1343 dquot->dq_dqb.dqb_btime == 0) { 1344 if (flags & DQUOT_SPACE_WARN) { 1345 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1346 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1347 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1348 } else { 1349 /* 1350 * We don't allow preallocation to exceed softlimit so exceeding will 1351 * be always printed 1352 */ 1353 ret = -EDQUOT; 1354 goto finish; 1355 } 1356 } 1357 finish: 1358 /* 1359 * We have to be careful and go through warning generation & grace time 1360 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1361 * only here... 1362 */ 1363 if (flags & DQUOT_SPACE_NOFAIL) 1364 ret = 0; 1365 if (!ret) { 1366 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1367 dquot->dq_dqb.dqb_curspace += space; 1368 } 1369 spin_unlock(&dquot->dq_dqb_lock); 1370 return ret; 1371 } 1372 1373 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1374 { 1375 qsize_t newinodes; 1376 1377 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1378 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1379 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1380 return QUOTA_NL_NOWARN; 1381 1382 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1383 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1384 return QUOTA_NL_ISOFTBELOW; 1385 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1386 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1387 return QUOTA_NL_IHARDBELOW; 1388 return QUOTA_NL_NOWARN; 1389 } 1390 1391 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1392 { 1393 qsize_t tspace; 1394 1395 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1396 1397 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1398 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1399 return QUOTA_NL_NOWARN; 1400 1401 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1402 return QUOTA_NL_BSOFTBELOW; 1403 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1404 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1405 return QUOTA_NL_BHARDBELOW; 1406 return QUOTA_NL_NOWARN; 1407 } 1408 1409 static int dquot_active(const struct inode *inode) 1410 { 1411 struct super_block *sb = inode->i_sb; 1412 1413 if (IS_NOQUOTA(inode)) 1414 return 0; 1415 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1416 } 1417 1418 /* 1419 * Initialize quota pointers in inode 1420 * 1421 * It is better to call this function outside of any transaction as it 1422 * might need a lot of space in journal for dquot structure allocation. 1423 */ 1424 static int __dquot_initialize(struct inode *inode, int type) 1425 { 1426 int cnt, init_needed = 0; 1427 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1428 struct super_block *sb = inode->i_sb; 1429 qsize_t rsv; 1430 int ret = 0; 1431 1432 if (!dquot_active(inode)) 1433 return 0; 1434 1435 dquots = i_dquot(inode); 1436 1437 /* First get references to structures we might need. */ 1438 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1439 struct kqid qid; 1440 kprojid_t projid; 1441 int rc; 1442 struct dquot *dquot; 1443 1444 if (type != -1 && cnt != type) 1445 continue; 1446 /* 1447 * The i_dquot should have been initialized in most cases, 1448 * we check it without locking here to avoid unnecessary 1449 * dqget()/dqput() calls. 1450 */ 1451 if (dquots[cnt]) 1452 continue; 1453 1454 if (!sb_has_quota_active(sb, cnt)) 1455 continue; 1456 1457 init_needed = 1; 1458 1459 switch (cnt) { 1460 case USRQUOTA: 1461 qid = make_kqid_uid(inode->i_uid); 1462 break; 1463 case GRPQUOTA: 1464 qid = make_kqid_gid(inode->i_gid); 1465 break; 1466 case PRJQUOTA: 1467 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1468 if (rc) 1469 continue; 1470 qid = make_kqid_projid(projid); 1471 break; 1472 } 1473 dquot = dqget(sb, qid); 1474 if (IS_ERR(dquot)) { 1475 /* We raced with somebody turning quotas off... */ 1476 if (PTR_ERR(dquot) != -ESRCH) { 1477 ret = PTR_ERR(dquot); 1478 goto out_put; 1479 } 1480 dquot = NULL; 1481 } 1482 got[cnt] = dquot; 1483 } 1484 1485 /* All required i_dquot has been initialized */ 1486 if (!init_needed) 1487 return 0; 1488 1489 spin_lock(&dq_data_lock); 1490 if (IS_NOQUOTA(inode)) 1491 goto out_lock; 1492 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1493 if (type != -1 && cnt != type) 1494 continue; 1495 /* Avoid races with quotaoff() */ 1496 if (!sb_has_quota_active(sb, cnt)) 1497 continue; 1498 /* We could race with quotaon or dqget() could have failed */ 1499 if (!got[cnt]) 1500 continue; 1501 if (!dquots[cnt]) { 1502 dquots[cnt] = got[cnt]; 1503 got[cnt] = NULL; 1504 /* 1505 * Make quota reservation system happy if someone 1506 * did a write before quota was turned on 1507 */ 1508 rsv = inode_get_rsv_space(inode); 1509 if (unlikely(rsv)) { 1510 spin_lock(&inode->i_lock); 1511 /* Get reservation again under proper lock */ 1512 rsv = __inode_get_rsv_space(inode); 1513 spin_lock(&dquots[cnt]->dq_dqb_lock); 1514 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1515 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1516 spin_unlock(&inode->i_lock); 1517 } 1518 } 1519 } 1520 out_lock: 1521 spin_unlock(&dq_data_lock); 1522 out_put: 1523 /* Drop unused references */ 1524 dqput_all(got); 1525 1526 return ret; 1527 } 1528 1529 int dquot_initialize(struct inode *inode) 1530 { 1531 return __dquot_initialize(inode, -1); 1532 } 1533 EXPORT_SYMBOL(dquot_initialize); 1534 1535 bool dquot_initialize_needed(struct inode *inode) 1536 { 1537 struct dquot **dquots; 1538 int i; 1539 1540 if (!dquot_active(inode)) 1541 return false; 1542 1543 dquots = i_dquot(inode); 1544 for (i = 0; i < MAXQUOTAS; i++) 1545 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1546 return true; 1547 return false; 1548 } 1549 EXPORT_SYMBOL(dquot_initialize_needed); 1550 1551 /* 1552 * Release all quotas referenced by inode. 1553 * 1554 * This function only be called on inode free or converting 1555 * a file to quota file, no other users for the i_dquot in 1556 * both cases, so we needn't call synchronize_srcu() after 1557 * clearing i_dquot. 1558 */ 1559 static void __dquot_drop(struct inode *inode) 1560 { 1561 int cnt; 1562 struct dquot **dquots = i_dquot(inode); 1563 struct dquot *put[MAXQUOTAS]; 1564 1565 spin_lock(&dq_data_lock); 1566 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1567 put[cnt] = dquots[cnt]; 1568 dquots[cnt] = NULL; 1569 } 1570 spin_unlock(&dq_data_lock); 1571 dqput_all(put); 1572 } 1573 1574 void dquot_drop(struct inode *inode) 1575 { 1576 struct dquot * const *dquots; 1577 int cnt; 1578 1579 if (IS_NOQUOTA(inode)) 1580 return; 1581 1582 /* 1583 * Test before calling to rule out calls from proc and such 1584 * where we are not allowed to block. Note that this is 1585 * actually reliable test even without the lock - the caller 1586 * must assure that nobody can come after the DQUOT_DROP and 1587 * add quota pointers back anyway. 1588 */ 1589 dquots = i_dquot(inode); 1590 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1591 if (dquots[cnt]) 1592 break; 1593 } 1594 1595 if (cnt < MAXQUOTAS) 1596 __dquot_drop(inode); 1597 } 1598 EXPORT_SYMBOL(dquot_drop); 1599 1600 /* 1601 * inode_reserved_space is managed internally by quota, and protected by 1602 * i_lock similar to i_blocks+i_bytes. 1603 */ 1604 static qsize_t *inode_reserved_space(struct inode * inode) 1605 { 1606 /* Filesystem must explicitly define it's own method in order to use 1607 * quota reservation interface */ 1608 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1609 return inode->i_sb->dq_op->get_reserved_space(inode); 1610 } 1611 1612 static qsize_t __inode_get_rsv_space(struct inode *inode) 1613 { 1614 if (!inode->i_sb->dq_op->get_reserved_space) 1615 return 0; 1616 return *inode_reserved_space(inode); 1617 } 1618 1619 static qsize_t inode_get_rsv_space(struct inode *inode) 1620 { 1621 qsize_t ret; 1622 1623 if (!inode->i_sb->dq_op->get_reserved_space) 1624 return 0; 1625 spin_lock(&inode->i_lock); 1626 ret = __inode_get_rsv_space(inode); 1627 spin_unlock(&inode->i_lock); 1628 return ret; 1629 } 1630 1631 /* 1632 * This functions updates i_blocks+i_bytes fields and quota information 1633 * (together with appropriate checks). 1634 * 1635 * NOTE: We absolutely rely on the fact that caller dirties the inode 1636 * (usually helpers in quotaops.h care about this) and holds a handle for 1637 * the current transaction so that dquot write and inode write go into the 1638 * same transaction. 1639 */ 1640 1641 /* 1642 * This operation can block, but only after everything is updated 1643 */ 1644 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1645 { 1646 int cnt, ret = 0, index; 1647 struct dquot_warn warn[MAXQUOTAS]; 1648 int reserve = flags & DQUOT_SPACE_RESERVE; 1649 struct dquot **dquots; 1650 1651 if (!dquot_active(inode)) { 1652 if (reserve) { 1653 spin_lock(&inode->i_lock); 1654 *inode_reserved_space(inode) += number; 1655 spin_unlock(&inode->i_lock); 1656 } else { 1657 inode_add_bytes(inode, number); 1658 } 1659 goto out; 1660 } 1661 1662 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1663 warn[cnt].w_type = QUOTA_NL_NOWARN; 1664 1665 dquots = i_dquot(inode); 1666 index = srcu_read_lock(&dquot_srcu); 1667 spin_lock(&inode->i_lock); 1668 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1669 if (!dquots[cnt]) 1670 continue; 1671 if (reserve) { 1672 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1673 &warn[cnt]); 1674 } else { 1675 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1676 &warn[cnt]); 1677 } 1678 if (ret) { 1679 /* Back out changes we already did */ 1680 for (cnt--; cnt >= 0; cnt--) { 1681 if (!dquots[cnt]) 1682 continue; 1683 spin_lock(&dquots[cnt]->dq_dqb_lock); 1684 if (reserve) 1685 dquot_free_reserved_space(dquots[cnt], 1686 number); 1687 else 1688 dquot_decr_space(dquots[cnt], number); 1689 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1690 } 1691 spin_unlock(&inode->i_lock); 1692 goto out_flush_warn; 1693 } 1694 } 1695 if (reserve) 1696 *inode_reserved_space(inode) += number; 1697 else 1698 __inode_add_bytes(inode, number); 1699 spin_unlock(&inode->i_lock); 1700 1701 if (reserve) 1702 goto out_flush_warn; 1703 mark_all_dquot_dirty(dquots); 1704 out_flush_warn: 1705 srcu_read_unlock(&dquot_srcu, index); 1706 flush_warnings(warn); 1707 out: 1708 return ret; 1709 } 1710 EXPORT_SYMBOL(__dquot_alloc_space); 1711 1712 /* 1713 * This operation can block, but only after everything is updated 1714 */ 1715 int dquot_alloc_inode(struct inode *inode) 1716 { 1717 int cnt, ret = 0, index; 1718 struct dquot_warn warn[MAXQUOTAS]; 1719 struct dquot * const *dquots; 1720 1721 if (!dquot_active(inode)) 1722 return 0; 1723 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1724 warn[cnt].w_type = QUOTA_NL_NOWARN; 1725 1726 dquots = i_dquot(inode); 1727 index = srcu_read_lock(&dquot_srcu); 1728 spin_lock(&inode->i_lock); 1729 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1730 if (!dquots[cnt]) 1731 continue; 1732 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1733 if (ret) { 1734 for (cnt--; cnt >= 0; cnt--) { 1735 if (!dquots[cnt]) 1736 continue; 1737 /* Back out changes we already did */ 1738 spin_lock(&dquots[cnt]->dq_dqb_lock); 1739 dquot_decr_inodes(dquots[cnt], 1); 1740 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1741 } 1742 goto warn_put_all; 1743 } 1744 } 1745 1746 warn_put_all: 1747 spin_unlock(&inode->i_lock); 1748 if (ret == 0) 1749 mark_all_dquot_dirty(dquots); 1750 srcu_read_unlock(&dquot_srcu, index); 1751 flush_warnings(warn); 1752 return ret; 1753 } 1754 EXPORT_SYMBOL(dquot_alloc_inode); 1755 1756 /* 1757 * Convert in-memory reserved quotas to real consumed quotas 1758 */ 1759 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1760 { 1761 struct dquot **dquots; 1762 int cnt, index; 1763 1764 if (!dquot_active(inode)) { 1765 spin_lock(&inode->i_lock); 1766 *inode_reserved_space(inode) -= number; 1767 __inode_add_bytes(inode, number); 1768 spin_unlock(&inode->i_lock); 1769 return 0; 1770 } 1771 1772 dquots = i_dquot(inode); 1773 index = srcu_read_lock(&dquot_srcu); 1774 spin_lock(&inode->i_lock); 1775 /* Claim reserved quotas to allocated quotas */ 1776 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1777 if (dquots[cnt]) { 1778 struct dquot *dquot = dquots[cnt]; 1779 1780 spin_lock(&dquot->dq_dqb_lock); 1781 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1782 number = dquot->dq_dqb.dqb_rsvspace; 1783 dquot->dq_dqb.dqb_curspace += number; 1784 dquot->dq_dqb.dqb_rsvspace -= number; 1785 spin_unlock(&dquot->dq_dqb_lock); 1786 } 1787 } 1788 /* Update inode bytes */ 1789 *inode_reserved_space(inode) -= number; 1790 __inode_add_bytes(inode, number); 1791 spin_unlock(&inode->i_lock); 1792 mark_all_dquot_dirty(dquots); 1793 srcu_read_unlock(&dquot_srcu, index); 1794 return 0; 1795 } 1796 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1797 1798 /* 1799 * Convert allocated space back to in-memory reserved quotas 1800 */ 1801 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1802 { 1803 struct dquot **dquots; 1804 int cnt, index; 1805 1806 if (!dquot_active(inode)) { 1807 spin_lock(&inode->i_lock); 1808 *inode_reserved_space(inode) += number; 1809 __inode_sub_bytes(inode, number); 1810 spin_unlock(&inode->i_lock); 1811 return; 1812 } 1813 1814 dquots = i_dquot(inode); 1815 index = srcu_read_lock(&dquot_srcu); 1816 spin_lock(&inode->i_lock); 1817 /* Claim reserved quotas to allocated quotas */ 1818 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1819 if (dquots[cnt]) { 1820 struct dquot *dquot = dquots[cnt]; 1821 1822 spin_lock(&dquot->dq_dqb_lock); 1823 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1824 number = dquot->dq_dqb.dqb_curspace; 1825 dquot->dq_dqb.dqb_rsvspace += number; 1826 dquot->dq_dqb.dqb_curspace -= number; 1827 spin_unlock(&dquot->dq_dqb_lock); 1828 } 1829 } 1830 /* Update inode bytes */ 1831 *inode_reserved_space(inode) += number; 1832 __inode_sub_bytes(inode, number); 1833 spin_unlock(&inode->i_lock); 1834 mark_all_dquot_dirty(dquots); 1835 srcu_read_unlock(&dquot_srcu, index); 1836 return; 1837 } 1838 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1839 1840 /* 1841 * This operation can block, but only after everything is updated 1842 */ 1843 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1844 { 1845 unsigned int cnt; 1846 struct dquot_warn warn[MAXQUOTAS]; 1847 struct dquot **dquots; 1848 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1849 1850 if (!dquot_active(inode)) { 1851 if (reserve) { 1852 spin_lock(&inode->i_lock); 1853 *inode_reserved_space(inode) -= number; 1854 spin_unlock(&inode->i_lock); 1855 } else { 1856 inode_sub_bytes(inode, number); 1857 } 1858 return; 1859 } 1860 1861 dquots = i_dquot(inode); 1862 index = srcu_read_lock(&dquot_srcu); 1863 spin_lock(&inode->i_lock); 1864 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1865 int wtype; 1866 1867 warn[cnt].w_type = QUOTA_NL_NOWARN; 1868 if (!dquots[cnt]) 1869 continue; 1870 spin_lock(&dquots[cnt]->dq_dqb_lock); 1871 wtype = info_bdq_free(dquots[cnt], number); 1872 if (wtype != QUOTA_NL_NOWARN) 1873 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1874 if (reserve) 1875 dquot_free_reserved_space(dquots[cnt], number); 1876 else 1877 dquot_decr_space(dquots[cnt], number); 1878 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1879 } 1880 if (reserve) 1881 *inode_reserved_space(inode) -= number; 1882 else 1883 __inode_sub_bytes(inode, number); 1884 spin_unlock(&inode->i_lock); 1885 1886 if (reserve) 1887 goto out_unlock; 1888 mark_all_dquot_dirty(dquots); 1889 out_unlock: 1890 srcu_read_unlock(&dquot_srcu, index); 1891 flush_warnings(warn); 1892 } 1893 EXPORT_SYMBOL(__dquot_free_space); 1894 1895 /* 1896 * This operation can block, but only after everything is updated 1897 */ 1898 void dquot_free_inode(struct inode *inode) 1899 { 1900 unsigned int cnt; 1901 struct dquot_warn warn[MAXQUOTAS]; 1902 struct dquot * const *dquots; 1903 int index; 1904 1905 if (!dquot_active(inode)) 1906 return; 1907 1908 dquots = i_dquot(inode); 1909 index = srcu_read_lock(&dquot_srcu); 1910 spin_lock(&inode->i_lock); 1911 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1912 int wtype; 1913 1914 warn[cnt].w_type = QUOTA_NL_NOWARN; 1915 if (!dquots[cnt]) 1916 continue; 1917 spin_lock(&dquots[cnt]->dq_dqb_lock); 1918 wtype = info_idq_free(dquots[cnt], 1); 1919 if (wtype != QUOTA_NL_NOWARN) 1920 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1921 dquot_decr_inodes(dquots[cnt], 1); 1922 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1923 } 1924 spin_unlock(&inode->i_lock); 1925 mark_all_dquot_dirty(dquots); 1926 srcu_read_unlock(&dquot_srcu, index); 1927 flush_warnings(warn); 1928 } 1929 EXPORT_SYMBOL(dquot_free_inode); 1930 1931 /* 1932 * Transfer the number of inode and blocks from one diskquota to an other. 1933 * On success, dquot references in transfer_to are consumed and references 1934 * to original dquots that need to be released are placed there. On failure, 1935 * references are kept untouched. 1936 * 1937 * This operation can block, but only after everything is updated 1938 * A transaction must be started when entering this function. 1939 * 1940 * We are holding reference on transfer_from & transfer_to, no need to 1941 * protect them by srcu_read_lock(). 1942 */ 1943 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1944 { 1945 qsize_t cur_space; 1946 qsize_t rsv_space = 0; 1947 qsize_t inode_usage = 1; 1948 struct dquot *transfer_from[MAXQUOTAS] = {}; 1949 int cnt, ret = 0; 1950 char is_valid[MAXQUOTAS] = {}; 1951 struct dquot_warn warn_to[MAXQUOTAS]; 1952 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1953 struct dquot_warn warn_from_space[MAXQUOTAS]; 1954 1955 if (IS_NOQUOTA(inode)) 1956 return 0; 1957 1958 if (inode->i_sb->dq_op->get_inode_usage) { 1959 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1960 if (ret) 1961 return ret; 1962 } 1963 1964 /* Initialize the arrays */ 1965 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1966 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1967 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1968 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1969 } 1970 1971 spin_lock(&dq_data_lock); 1972 spin_lock(&inode->i_lock); 1973 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1974 spin_unlock(&inode->i_lock); 1975 spin_unlock(&dq_data_lock); 1976 return 0; 1977 } 1978 cur_space = __inode_get_bytes(inode); 1979 rsv_space = __inode_get_rsv_space(inode); 1980 /* 1981 * Build the transfer_from list, check limits, and update usage in 1982 * the target structures. 1983 */ 1984 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1985 /* 1986 * Skip changes for same uid or gid or for turned off quota-type. 1987 */ 1988 if (!transfer_to[cnt]) 1989 continue; 1990 /* Avoid races with quotaoff() */ 1991 if (!sb_has_quota_active(inode->i_sb, cnt)) 1992 continue; 1993 is_valid[cnt] = 1; 1994 transfer_from[cnt] = i_dquot(inode)[cnt]; 1995 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 1996 &warn_to[cnt]); 1997 if (ret) 1998 goto over_quota; 1999 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 0, 2000 &warn_to[cnt]); 2001 if (ret) { 2002 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2003 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2004 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2005 goto over_quota; 2006 } 2007 } 2008 2009 /* Decrease usage for source structures and update quota pointers */ 2010 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2011 if (!is_valid[cnt]) 2012 continue; 2013 /* Due to IO error we might not have transfer_from[] structure */ 2014 if (transfer_from[cnt]) { 2015 int wtype; 2016 2017 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2018 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2019 if (wtype != QUOTA_NL_NOWARN) 2020 prepare_warning(&warn_from_inodes[cnt], 2021 transfer_from[cnt], wtype); 2022 wtype = info_bdq_free(transfer_from[cnt], 2023 cur_space + rsv_space); 2024 if (wtype != QUOTA_NL_NOWARN) 2025 prepare_warning(&warn_from_space[cnt], 2026 transfer_from[cnt], wtype); 2027 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2028 dquot_decr_space(transfer_from[cnt], cur_space); 2029 dquot_free_reserved_space(transfer_from[cnt], 2030 rsv_space); 2031 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2032 } 2033 i_dquot(inode)[cnt] = transfer_to[cnt]; 2034 } 2035 spin_unlock(&inode->i_lock); 2036 spin_unlock(&dq_data_lock); 2037 2038 mark_all_dquot_dirty(transfer_from); 2039 mark_all_dquot_dirty(transfer_to); 2040 flush_warnings(warn_to); 2041 flush_warnings(warn_from_inodes); 2042 flush_warnings(warn_from_space); 2043 /* Pass back references to put */ 2044 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2045 if (is_valid[cnt]) 2046 transfer_to[cnt] = transfer_from[cnt]; 2047 return 0; 2048 over_quota: 2049 /* Back out changes we already did */ 2050 for (cnt--; cnt >= 0; cnt--) { 2051 if (!is_valid[cnt]) 2052 continue; 2053 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2054 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2055 dquot_decr_space(transfer_to[cnt], cur_space); 2056 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2057 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2058 } 2059 spin_unlock(&inode->i_lock); 2060 spin_unlock(&dq_data_lock); 2061 flush_warnings(warn_to); 2062 return ret; 2063 } 2064 EXPORT_SYMBOL(__dquot_transfer); 2065 2066 /* Wrapper for transferring ownership of an inode for uid/gid only 2067 * Called from FSXXX_setattr() 2068 */ 2069 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2070 { 2071 struct dquot *transfer_to[MAXQUOTAS] = {}; 2072 struct dquot *dquot; 2073 struct super_block *sb = inode->i_sb; 2074 int ret; 2075 2076 if (!dquot_active(inode)) 2077 return 0; 2078 2079 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2080 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2081 if (IS_ERR(dquot)) { 2082 if (PTR_ERR(dquot) != -ESRCH) { 2083 ret = PTR_ERR(dquot); 2084 goto out_put; 2085 } 2086 dquot = NULL; 2087 } 2088 transfer_to[USRQUOTA] = dquot; 2089 } 2090 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2091 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2092 if (IS_ERR(dquot)) { 2093 if (PTR_ERR(dquot) != -ESRCH) { 2094 ret = PTR_ERR(dquot); 2095 goto out_put; 2096 } 2097 dquot = NULL; 2098 } 2099 transfer_to[GRPQUOTA] = dquot; 2100 } 2101 ret = __dquot_transfer(inode, transfer_to); 2102 out_put: 2103 dqput_all(transfer_to); 2104 return ret; 2105 } 2106 EXPORT_SYMBOL(dquot_transfer); 2107 2108 /* 2109 * Write info of quota file to disk 2110 */ 2111 int dquot_commit_info(struct super_block *sb, int type) 2112 { 2113 struct quota_info *dqopt = sb_dqopt(sb); 2114 2115 return dqopt->ops[type]->write_file_info(sb, type); 2116 } 2117 EXPORT_SYMBOL(dquot_commit_info); 2118 2119 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2120 { 2121 struct quota_info *dqopt = sb_dqopt(sb); 2122 2123 if (!sb_has_quota_active(sb, qid->type)) 2124 return -ESRCH; 2125 if (!dqopt->ops[qid->type]->get_next_id) 2126 return -ENOSYS; 2127 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2128 } 2129 EXPORT_SYMBOL(dquot_get_next_id); 2130 2131 /* 2132 * Definitions of diskquota operations. 2133 */ 2134 const struct dquot_operations dquot_operations = { 2135 .write_dquot = dquot_commit, 2136 .acquire_dquot = dquot_acquire, 2137 .release_dquot = dquot_release, 2138 .mark_dirty = dquot_mark_dquot_dirty, 2139 .write_info = dquot_commit_info, 2140 .alloc_dquot = dquot_alloc, 2141 .destroy_dquot = dquot_destroy, 2142 .get_next_id = dquot_get_next_id, 2143 }; 2144 EXPORT_SYMBOL(dquot_operations); 2145 2146 /* 2147 * Generic helper for ->open on filesystems supporting disk quotas. 2148 */ 2149 int dquot_file_open(struct inode *inode, struct file *file) 2150 { 2151 int error; 2152 2153 error = generic_file_open(inode, file); 2154 if (!error && (file->f_mode & FMODE_WRITE)) 2155 error = dquot_initialize(inode); 2156 return error; 2157 } 2158 EXPORT_SYMBOL(dquot_file_open); 2159 2160 /* 2161 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2162 */ 2163 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2164 { 2165 int cnt, ret = 0; 2166 struct quota_info *dqopt = sb_dqopt(sb); 2167 struct inode *toputinode[MAXQUOTAS]; 2168 2169 /* s_umount should be held in exclusive mode */ 2170 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2171 up_read(&sb->s_umount); 2172 2173 /* Cannot turn off usage accounting without turning off limits, or 2174 * suspend quotas and simultaneously turn quotas off. */ 2175 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2176 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2177 DQUOT_USAGE_ENABLED))) 2178 return -EINVAL; 2179 2180 /* 2181 * Skip everything if there's nothing to do. We have to do this because 2182 * sometimes we are called when fill_super() failed and calling 2183 * sync_fs() in such cases does no good. 2184 */ 2185 if (!sb_any_quota_loaded(sb)) 2186 return 0; 2187 2188 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2189 toputinode[cnt] = NULL; 2190 if (type != -1 && cnt != type) 2191 continue; 2192 if (!sb_has_quota_loaded(sb, cnt)) 2193 continue; 2194 2195 if (flags & DQUOT_SUSPENDED) { 2196 spin_lock(&dq_state_lock); 2197 dqopt->flags |= 2198 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2199 spin_unlock(&dq_state_lock); 2200 } else { 2201 spin_lock(&dq_state_lock); 2202 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2203 /* Turning off suspended quotas? */ 2204 if (!sb_has_quota_loaded(sb, cnt) && 2205 sb_has_quota_suspended(sb, cnt)) { 2206 dqopt->flags &= ~dquot_state_flag( 2207 DQUOT_SUSPENDED, cnt); 2208 spin_unlock(&dq_state_lock); 2209 iput(dqopt->files[cnt]); 2210 dqopt->files[cnt] = NULL; 2211 continue; 2212 } 2213 spin_unlock(&dq_state_lock); 2214 } 2215 2216 /* We still have to keep quota loaded? */ 2217 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2218 continue; 2219 2220 /* Note: these are blocking operations */ 2221 drop_dquot_ref(sb, cnt); 2222 invalidate_dquots(sb, cnt); 2223 /* 2224 * Now all dquots should be invalidated, all writes done so we 2225 * should be only users of the info. No locks needed. 2226 */ 2227 if (info_dirty(&dqopt->info[cnt])) 2228 sb->dq_op->write_info(sb, cnt); 2229 if (dqopt->ops[cnt]->free_file_info) 2230 dqopt->ops[cnt]->free_file_info(sb, cnt); 2231 put_quota_format(dqopt->info[cnt].dqi_format); 2232 2233 toputinode[cnt] = dqopt->files[cnt]; 2234 if (!sb_has_quota_loaded(sb, cnt)) 2235 dqopt->files[cnt] = NULL; 2236 dqopt->info[cnt].dqi_flags = 0; 2237 dqopt->info[cnt].dqi_igrace = 0; 2238 dqopt->info[cnt].dqi_bgrace = 0; 2239 dqopt->ops[cnt] = NULL; 2240 } 2241 2242 /* Skip syncing and setting flags if quota files are hidden */ 2243 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2244 goto put_inodes; 2245 2246 /* Sync the superblock so that buffers with quota data are written to 2247 * disk (and so userspace sees correct data afterwards). */ 2248 if (sb->s_op->sync_fs) 2249 sb->s_op->sync_fs(sb, 1); 2250 sync_blockdev(sb->s_bdev); 2251 /* Now the quota files are just ordinary files and we can set the 2252 * inode flags back. Moreover we discard the pagecache so that 2253 * userspace sees the writes we did bypassing the pagecache. We 2254 * must also discard the blockdev buffers so that we see the 2255 * changes done by userspace on the next quotaon() */ 2256 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2257 /* This can happen when suspending quotas on remount-ro... */ 2258 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { 2259 inode_lock(toputinode[cnt]); 2260 toputinode[cnt]->i_flags &= ~S_NOQUOTA; 2261 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 2262 inode_unlock(toputinode[cnt]); 2263 mark_inode_dirty_sync(toputinode[cnt]); 2264 } 2265 if (sb->s_bdev) 2266 invalidate_bdev(sb->s_bdev); 2267 put_inodes: 2268 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2269 if (toputinode[cnt]) { 2270 /* On remount RO, we keep the inode pointer so that we 2271 * can reenable quota on the subsequent remount RW. We 2272 * have to check 'flags' variable and not use sb_has_ 2273 * function because another quotaon / quotaoff could 2274 * change global state before we got here. We refuse 2275 * to suspend quotas when there is pending delete on 2276 * the quota file... */ 2277 if (!(flags & DQUOT_SUSPENDED)) 2278 iput(toputinode[cnt]); 2279 else if (!toputinode[cnt]->i_nlink) 2280 ret = -EBUSY; 2281 } 2282 return ret; 2283 } 2284 EXPORT_SYMBOL(dquot_disable); 2285 2286 int dquot_quota_off(struct super_block *sb, int type) 2287 { 2288 return dquot_disable(sb, type, 2289 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2290 } 2291 EXPORT_SYMBOL(dquot_quota_off); 2292 2293 /* 2294 * Turn quotas on on a device 2295 */ 2296 2297 /* 2298 * Helper function to turn quotas on when we already have the inode of 2299 * quota file and no quota information is loaded. 2300 */ 2301 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2302 unsigned int flags) 2303 { 2304 struct quota_format_type *fmt = find_quota_format(format_id); 2305 struct super_block *sb = inode->i_sb; 2306 struct quota_info *dqopt = sb_dqopt(sb); 2307 int error; 2308 2309 if (!fmt) 2310 return -ESRCH; 2311 if (!S_ISREG(inode->i_mode)) { 2312 error = -EACCES; 2313 goto out_fmt; 2314 } 2315 if (IS_RDONLY(inode)) { 2316 error = -EROFS; 2317 goto out_fmt; 2318 } 2319 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2320 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2321 error = -EINVAL; 2322 goto out_fmt; 2323 } 2324 /* Filesystems outside of init_user_ns not yet supported */ 2325 if (sb->s_user_ns != &init_user_ns) { 2326 error = -EINVAL; 2327 goto out_fmt; 2328 } 2329 /* Usage always has to be set... */ 2330 if (!(flags & DQUOT_USAGE_ENABLED)) { 2331 error = -EINVAL; 2332 goto out_fmt; 2333 } 2334 if (sb_has_quota_loaded(sb, type)) { 2335 error = -EBUSY; 2336 goto out_fmt; 2337 } 2338 2339 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2340 /* As we bypass the pagecache we must now flush all the 2341 * dirty data and invalidate caches so that kernel sees 2342 * changes from userspace. It is not enough to just flush 2343 * the quota file since if blocksize < pagesize, invalidation 2344 * of the cache could fail because of other unrelated dirty 2345 * data */ 2346 sync_filesystem(sb); 2347 invalidate_bdev(sb->s_bdev); 2348 } 2349 2350 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2351 /* We don't want quota and atime on quota files (deadlocks 2352 * possible) Also nobody should write to the file - we use 2353 * special IO operations which ignore the immutable bit. */ 2354 inode_lock(inode); 2355 inode->i_flags |= S_NOQUOTA; 2356 inode_unlock(inode); 2357 /* 2358 * When S_NOQUOTA is set, remove dquot references as no more 2359 * references can be added 2360 */ 2361 __dquot_drop(inode); 2362 } 2363 2364 error = -EIO; 2365 dqopt->files[type] = igrab(inode); 2366 if (!dqopt->files[type]) 2367 goto out_file_flags; 2368 error = -EINVAL; 2369 if (!fmt->qf_ops->check_quota_file(sb, type)) 2370 goto out_file_init; 2371 2372 dqopt->ops[type] = fmt->qf_ops; 2373 dqopt->info[type].dqi_format = fmt; 2374 dqopt->info[type].dqi_fmt_id = format_id; 2375 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2376 error = dqopt->ops[type]->read_file_info(sb, type); 2377 if (error < 0) 2378 goto out_file_init; 2379 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2380 spin_lock(&dq_data_lock); 2381 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2382 spin_unlock(&dq_data_lock); 2383 } 2384 spin_lock(&dq_state_lock); 2385 dqopt->flags |= dquot_state_flag(flags, type); 2386 spin_unlock(&dq_state_lock); 2387 2388 error = add_dquot_ref(sb, type); 2389 if (error) 2390 dquot_disable(sb, type, flags); 2391 2392 return error; 2393 out_file_init: 2394 dqopt->files[type] = NULL; 2395 iput(inode); 2396 out_file_flags: 2397 inode_lock(inode); 2398 inode->i_flags &= ~S_NOQUOTA; 2399 inode_unlock(inode); 2400 out_fmt: 2401 put_quota_format(fmt); 2402 2403 return error; 2404 } 2405 2406 /* Reenable quotas on remount RW */ 2407 int dquot_resume(struct super_block *sb, int type) 2408 { 2409 struct quota_info *dqopt = sb_dqopt(sb); 2410 struct inode *inode; 2411 int ret = 0, cnt; 2412 unsigned int flags; 2413 2414 /* s_umount should be held in exclusive mode */ 2415 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2416 up_read(&sb->s_umount); 2417 2418 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2419 if (type != -1 && cnt != type) 2420 continue; 2421 if (!sb_has_quota_suspended(sb, cnt)) 2422 continue; 2423 2424 inode = dqopt->files[cnt]; 2425 dqopt->files[cnt] = NULL; 2426 spin_lock(&dq_state_lock); 2427 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2428 DQUOT_LIMITS_ENABLED, 2429 cnt); 2430 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2431 spin_unlock(&dq_state_lock); 2432 2433 flags = dquot_generic_flag(flags, cnt); 2434 ret = vfs_load_quota_inode(inode, cnt, 2435 dqopt->info[cnt].dqi_fmt_id, flags); 2436 iput(inode); 2437 } 2438 2439 return ret; 2440 } 2441 EXPORT_SYMBOL(dquot_resume); 2442 2443 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2444 const struct path *path) 2445 { 2446 int error = security_quota_on(path->dentry); 2447 if (error) 2448 return error; 2449 /* Quota file not on the same filesystem? */ 2450 if (path->dentry->d_sb != sb) 2451 error = -EXDEV; 2452 else 2453 error = vfs_load_quota_inode(d_inode(path->dentry), type, 2454 format_id, DQUOT_USAGE_ENABLED | 2455 DQUOT_LIMITS_ENABLED); 2456 return error; 2457 } 2458 EXPORT_SYMBOL(dquot_quota_on); 2459 2460 /* 2461 * More powerful function for turning on quotas allowing setting 2462 * of individual quota flags 2463 */ 2464 int dquot_enable(struct inode *inode, int type, int format_id, 2465 unsigned int flags) 2466 { 2467 struct super_block *sb = inode->i_sb; 2468 2469 /* Just unsuspend quotas? */ 2470 BUG_ON(flags & DQUOT_SUSPENDED); 2471 /* s_umount should be held in exclusive mode */ 2472 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2473 up_read(&sb->s_umount); 2474 2475 if (!flags) 2476 return 0; 2477 /* Just updating flags needed? */ 2478 if (sb_has_quota_loaded(sb, type)) { 2479 if (flags & DQUOT_USAGE_ENABLED && 2480 sb_has_quota_usage_enabled(sb, type)) 2481 return -EBUSY; 2482 if (flags & DQUOT_LIMITS_ENABLED && 2483 sb_has_quota_limits_enabled(sb, type)) 2484 return -EBUSY; 2485 spin_lock(&dq_state_lock); 2486 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2487 spin_unlock(&dq_state_lock); 2488 return 0; 2489 } 2490 2491 return vfs_load_quota_inode(inode, type, format_id, flags); 2492 } 2493 EXPORT_SYMBOL(dquot_enable); 2494 2495 /* 2496 * This function is used when filesystem needs to initialize quotas 2497 * during mount time. 2498 */ 2499 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2500 int format_id, int type) 2501 { 2502 struct dentry *dentry; 2503 int error; 2504 2505 dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2506 if (IS_ERR(dentry)) 2507 return PTR_ERR(dentry); 2508 2509 if (d_really_is_negative(dentry)) { 2510 error = -ENOENT; 2511 goto out; 2512 } 2513 2514 error = security_quota_on(dentry); 2515 if (!error) 2516 error = vfs_load_quota_inode(d_inode(dentry), type, format_id, 2517 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2518 2519 out: 2520 dput(dentry); 2521 return error; 2522 } 2523 EXPORT_SYMBOL(dquot_quota_on_mount); 2524 2525 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2526 { 2527 int ret; 2528 int type; 2529 struct quota_info *dqopt = sb_dqopt(sb); 2530 2531 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2532 return -ENOSYS; 2533 /* Accounting cannot be turned on while fs is mounted */ 2534 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2535 if (!flags) 2536 return -EINVAL; 2537 for (type = 0; type < MAXQUOTAS; type++) { 2538 if (!(flags & qtype_enforce_flag(type))) 2539 continue; 2540 /* Can't enforce without accounting */ 2541 if (!sb_has_quota_usage_enabled(sb, type)) 2542 return -EINVAL; 2543 ret = dquot_enable(dqopt->files[type], type, 2544 dqopt->info[type].dqi_fmt_id, 2545 DQUOT_LIMITS_ENABLED); 2546 if (ret < 0) 2547 goto out_err; 2548 } 2549 return 0; 2550 out_err: 2551 /* Backout enforcement enablement we already did */ 2552 for (type--; type >= 0; type--) { 2553 if (flags & qtype_enforce_flag(type)) 2554 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2555 } 2556 /* Error code translation for better compatibility with XFS */ 2557 if (ret == -EBUSY) 2558 ret = -EEXIST; 2559 return ret; 2560 } 2561 2562 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2563 { 2564 int ret; 2565 int type; 2566 struct quota_info *dqopt = sb_dqopt(sb); 2567 2568 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2569 return -ENOSYS; 2570 /* 2571 * We don't support turning off accounting via quotactl. In principle 2572 * quota infrastructure can do this but filesystems don't expect 2573 * userspace to be able to do it. 2574 */ 2575 if (flags & 2576 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2577 return -EOPNOTSUPP; 2578 2579 /* Filter out limits not enabled */ 2580 for (type = 0; type < MAXQUOTAS; type++) 2581 if (!sb_has_quota_limits_enabled(sb, type)) 2582 flags &= ~qtype_enforce_flag(type); 2583 /* Nothing left? */ 2584 if (!flags) 2585 return -EEXIST; 2586 for (type = 0; type < MAXQUOTAS; type++) { 2587 if (flags & qtype_enforce_flag(type)) { 2588 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2589 if (ret < 0) 2590 goto out_err; 2591 } 2592 } 2593 return 0; 2594 out_err: 2595 /* Backout enforcement disabling we already did */ 2596 for (type--; type >= 0; type--) { 2597 if (flags & qtype_enforce_flag(type)) 2598 dquot_enable(dqopt->files[type], type, 2599 dqopt->info[type].dqi_fmt_id, 2600 DQUOT_LIMITS_ENABLED); 2601 } 2602 return ret; 2603 } 2604 2605 /* Generic routine for getting common part of quota structure */ 2606 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2607 { 2608 struct mem_dqblk *dm = &dquot->dq_dqb; 2609 2610 memset(di, 0, sizeof(*di)); 2611 spin_lock(&dquot->dq_dqb_lock); 2612 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2613 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2614 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2615 di->d_ino_softlimit = dm->dqb_isoftlimit; 2616 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2617 di->d_ino_count = dm->dqb_curinodes; 2618 di->d_spc_timer = dm->dqb_btime; 2619 di->d_ino_timer = dm->dqb_itime; 2620 spin_unlock(&dquot->dq_dqb_lock); 2621 } 2622 2623 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2624 struct qc_dqblk *di) 2625 { 2626 struct dquot *dquot; 2627 2628 dquot = dqget(sb, qid); 2629 if (IS_ERR(dquot)) 2630 return PTR_ERR(dquot); 2631 do_get_dqblk(dquot, di); 2632 dqput(dquot); 2633 2634 return 0; 2635 } 2636 EXPORT_SYMBOL(dquot_get_dqblk); 2637 2638 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2639 struct qc_dqblk *di) 2640 { 2641 struct dquot *dquot; 2642 int err; 2643 2644 if (!sb->dq_op->get_next_id) 2645 return -ENOSYS; 2646 err = sb->dq_op->get_next_id(sb, qid); 2647 if (err < 0) 2648 return err; 2649 dquot = dqget(sb, *qid); 2650 if (IS_ERR(dquot)) 2651 return PTR_ERR(dquot); 2652 do_get_dqblk(dquot, di); 2653 dqput(dquot); 2654 2655 return 0; 2656 } 2657 EXPORT_SYMBOL(dquot_get_next_dqblk); 2658 2659 #define VFS_QC_MASK \ 2660 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2661 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2662 QC_SPC_TIMER | QC_INO_TIMER) 2663 2664 /* Generic routine for setting common part of quota structure */ 2665 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2666 { 2667 struct mem_dqblk *dm = &dquot->dq_dqb; 2668 int check_blim = 0, check_ilim = 0; 2669 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2670 2671 if (di->d_fieldmask & ~VFS_QC_MASK) 2672 return -EINVAL; 2673 2674 if (((di->d_fieldmask & QC_SPC_SOFT) && 2675 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2676 ((di->d_fieldmask & QC_SPC_HARD) && 2677 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2678 ((di->d_fieldmask & QC_INO_SOFT) && 2679 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2680 ((di->d_fieldmask & QC_INO_HARD) && 2681 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2682 return -ERANGE; 2683 2684 spin_lock(&dquot->dq_dqb_lock); 2685 if (di->d_fieldmask & QC_SPACE) { 2686 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2687 check_blim = 1; 2688 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2689 } 2690 2691 if (di->d_fieldmask & QC_SPC_SOFT) 2692 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2693 if (di->d_fieldmask & QC_SPC_HARD) 2694 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2695 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2696 check_blim = 1; 2697 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2698 } 2699 2700 if (di->d_fieldmask & QC_INO_COUNT) { 2701 dm->dqb_curinodes = di->d_ino_count; 2702 check_ilim = 1; 2703 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2704 } 2705 2706 if (di->d_fieldmask & QC_INO_SOFT) 2707 dm->dqb_isoftlimit = di->d_ino_softlimit; 2708 if (di->d_fieldmask & QC_INO_HARD) 2709 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2710 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2711 check_ilim = 1; 2712 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2713 } 2714 2715 if (di->d_fieldmask & QC_SPC_TIMER) { 2716 dm->dqb_btime = di->d_spc_timer; 2717 check_blim = 1; 2718 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2719 } 2720 2721 if (di->d_fieldmask & QC_INO_TIMER) { 2722 dm->dqb_itime = di->d_ino_timer; 2723 check_ilim = 1; 2724 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2725 } 2726 2727 if (check_blim) { 2728 if (!dm->dqb_bsoftlimit || 2729 dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) { 2730 dm->dqb_btime = 0; 2731 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2732 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2733 /* Set grace only if user hasn't provided his own... */ 2734 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2735 } 2736 if (check_ilim) { 2737 if (!dm->dqb_isoftlimit || 2738 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2739 dm->dqb_itime = 0; 2740 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2741 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2742 /* Set grace only if user hasn't provided his own... */ 2743 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2744 } 2745 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2746 dm->dqb_isoftlimit) 2747 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2748 else 2749 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2750 spin_unlock(&dquot->dq_dqb_lock); 2751 mark_dquot_dirty(dquot); 2752 2753 return 0; 2754 } 2755 2756 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2757 struct qc_dqblk *di) 2758 { 2759 struct dquot *dquot; 2760 int rc; 2761 2762 dquot = dqget(sb, qid); 2763 if (IS_ERR(dquot)) { 2764 rc = PTR_ERR(dquot); 2765 goto out; 2766 } 2767 rc = do_set_dqblk(dquot, di); 2768 dqput(dquot); 2769 out: 2770 return rc; 2771 } 2772 EXPORT_SYMBOL(dquot_set_dqblk); 2773 2774 /* Generic routine for getting common part of quota file information */ 2775 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2776 { 2777 struct mem_dqinfo *mi; 2778 struct qc_type_state *tstate; 2779 struct quota_info *dqopt = sb_dqopt(sb); 2780 int type; 2781 2782 memset(state, 0, sizeof(*state)); 2783 for (type = 0; type < MAXQUOTAS; type++) { 2784 if (!sb_has_quota_active(sb, type)) 2785 continue; 2786 tstate = state->s_state + type; 2787 mi = sb_dqopt(sb)->info + type; 2788 tstate->flags = QCI_ACCT_ENABLED; 2789 spin_lock(&dq_data_lock); 2790 if (mi->dqi_flags & DQF_SYS_FILE) 2791 tstate->flags |= QCI_SYSFILE; 2792 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2793 tstate->flags |= QCI_ROOT_SQUASH; 2794 if (sb_has_quota_limits_enabled(sb, type)) 2795 tstate->flags |= QCI_LIMITS_ENFORCED; 2796 tstate->spc_timelimit = mi->dqi_bgrace; 2797 tstate->ino_timelimit = mi->dqi_igrace; 2798 tstate->ino = dqopt->files[type]->i_ino; 2799 tstate->blocks = dqopt->files[type]->i_blocks; 2800 tstate->nextents = 1; /* We don't know... */ 2801 spin_unlock(&dq_data_lock); 2802 } 2803 return 0; 2804 } 2805 EXPORT_SYMBOL(dquot_get_state); 2806 2807 /* Generic routine for setting common part of quota file information */ 2808 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2809 { 2810 struct mem_dqinfo *mi; 2811 int err = 0; 2812 2813 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2814 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2815 return -EINVAL; 2816 if (!sb_has_quota_active(sb, type)) 2817 return -ESRCH; 2818 mi = sb_dqopt(sb)->info + type; 2819 if (ii->i_fieldmask & QC_FLAGS) { 2820 if ((ii->i_flags & QCI_ROOT_SQUASH && 2821 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2822 return -EINVAL; 2823 } 2824 spin_lock(&dq_data_lock); 2825 if (ii->i_fieldmask & QC_SPC_TIMER) 2826 mi->dqi_bgrace = ii->i_spc_timelimit; 2827 if (ii->i_fieldmask & QC_INO_TIMER) 2828 mi->dqi_igrace = ii->i_ino_timelimit; 2829 if (ii->i_fieldmask & QC_FLAGS) { 2830 if (ii->i_flags & QCI_ROOT_SQUASH) 2831 mi->dqi_flags |= DQF_ROOT_SQUASH; 2832 else 2833 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2834 } 2835 spin_unlock(&dq_data_lock); 2836 mark_info_dirty(sb, type); 2837 /* Force write to disk */ 2838 sb->dq_op->write_info(sb, type); 2839 return err; 2840 } 2841 EXPORT_SYMBOL(dquot_set_dqinfo); 2842 2843 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2844 .quota_enable = dquot_quota_enable, 2845 .quota_disable = dquot_quota_disable, 2846 .quota_sync = dquot_quota_sync, 2847 .get_state = dquot_get_state, 2848 .set_info = dquot_set_dqinfo, 2849 .get_dqblk = dquot_get_dqblk, 2850 .get_nextdqblk = dquot_get_next_dqblk, 2851 .set_dqblk = dquot_set_dqblk 2852 }; 2853 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2854 2855 static int do_proc_dqstats(struct ctl_table *table, int write, 2856 void __user *buffer, size_t *lenp, loff_t *ppos) 2857 { 2858 unsigned int type = (int *)table->data - dqstats.stat; 2859 2860 /* Update global table */ 2861 dqstats.stat[type] = 2862 percpu_counter_sum_positive(&dqstats.counter[type]); 2863 return proc_dointvec(table, write, buffer, lenp, ppos); 2864 } 2865 2866 static struct ctl_table fs_dqstats_table[] = { 2867 { 2868 .procname = "lookups", 2869 .data = &dqstats.stat[DQST_LOOKUPS], 2870 .maxlen = sizeof(int), 2871 .mode = 0444, 2872 .proc_handler = do_proc_dqstats, 2873 }, 2874 { 2875 .procname = "drops", 2876 .data = &dqstats.stat[DQST_DROPS], 2877 .maxlen = sizeof(int), 2878 .mode = 0444, 2879 .proc_handler = do_proc_dqstats, 2880 }, 2881 { 2882 .procname = "reads", 2883 .data = &dqstats.stat[DQST_READS], 2884 .maxlen = sizeof(int), 2885 .mode = 0444, 2886 .proc_handler = do_proc_dqstats, 2887 }, 2888 { 2889 .procname = "writes", 2890 .data = &dqstats.stat[DQST_WRITES], 2891 .maxlen = sizeof(int), 2892 .mode = 0444, 2893 .proc_handler = do_proc_dqstats, 2894 }, 2895 { 2896 .procname = "cache_hits", 2897 .data = &dqstats.stat[DQST_CACHE_HITS], 2898 .maxlen = sizeof(int), 2899 .mode = 0444, 2900 .proc_handler = do_proc_dqstats, 2901 }, 2902 { 2903 .procname = "allocated_dquots", 2904 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2905 .maxlen = sizeof(int), 2906 .mode = 0444, 2907 .proc_handler = do_proc_dqstats, 2908 }, 2909 { 2910 .procname = "free_dquots", 2911 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2912 .maxlen = sizeof(int), 2913 .mode = 0444, 2914 .proc_handler = do_proc_dqstats, 2915 }, 2916 { 2917 .procname = "syncs", 2918 .data = &dqstats.stat[DQST_SYNCS], 2919 .maxlen = sizeof(int), 2920 .mode = 0444, 2921 .proc_handler = do_proc_dqstats, 2922 }, 2923 #ifdef CONFIG_PRINT_QUOTA_WARNING 2924 { 2925 .procname = "warnings", 2926 .data = &flag_print_warnings, 2927 .maxlen = sizeof(int), 2928 .mode = 0644, 2929 .proc_handler = proc_dointvec, 2930 }, 2931 #endif 2932 { }, 2933 }; 2934 2935 static struct ctl_table fs_table[] = { 2936 { 2937 .procname = "quota", 2938 .mode = 0555, 2939 .child = fs_dqstats_table, 2940 }, 2941 { }, 2942 }; 2943 2944 static struct ctl_table sys_table[] = { 2945 { 2946 .procname = "fs", 2947 .mode = 0555, 2948 .child = fs_table, 2949 }, 2950 { }, 2951 }; 2952 2953 static int __init dquot_init(void) 2954 { 2955 int i, ret; 2956 unsigned long nr_hash, order; 2957 2958 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2959 2960 register_sysctl_table(sys_table); 2961 2962 dquot_cachep = kmem_cache_create("dquot", 2963 sizeof(struct dquot), sizeof(unsigned long) * 4, 2964 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2965 SLAB_MEM_SPREAD|SLAB_PANIC), 2966 NULL); 2967 2968 order = 0; 2969 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2970 if (!dquot_hash) 2971 panic("Cannot create dquot hash table"); 2972 2973 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2974 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2975 if (ret) 2976 panic("Cannot create dquot stat counters"); 2977 } 2978 2979 /* Find power-of-two hlist_heads which can fit into allocation */ 2980 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2981 dq_hash_bits = 0; 2982 do { 2983 dq_hash_bits++; 2984 } while (nr_hash >> dq_hash_bits); 2985 dq_hash_bits--; 2986 2987 nr_hash = 1UL << dq_hash_bits; 2988 dq_hash_mask = nr_hash - 1; 2989 for (i = 0; i < nr_hash; i++) 2990 INIT_HLIST_HEAD(dquot_hash + i); 2991 2992 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2993 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2994 2995 if (register_shrinker(&dqcache_shrinker)) 2996 panic("Cannot register dquot shrinker"); 2997 2998 return 0; 2999 } 3000 fs_initcall(dquot_init); 3001