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