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