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 (!ret && err) 648 ret = err; 649 dqput(dquot); 650 spin_lock(&dq_list_lock); 651 } 652 spin_unlock(&dq_list_lock); 653 } 654 655 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 656 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 657 && info_dirty(&dqopt->info[cnt])) 658 sb->dq_op->write_info(sb, cnt); 659 dqstats_inc(DQST_SYNCS); 660 661 return ret; 662 } 663 EXPORT_SYMBOL(dquot_writeback_dquots); 664 665 /* Write all dquot structures to disk and make them visible from userspace */ 666 int dquot_quota_sync(struct super_block *sb, int type) 667 { 668 struct quota_info *dqopt = sb_dqopt(sb); 669 int cnt; 670 int ret; 671 672 ret = dquot_writeback_dquots(sb, type); 673 if (ret) 674 return ret; 675 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 676 return 0; 677 678 /* This is not very clever (and fast) but currently I don't know about 679 * any other simple way of getting quota data to disk and we must get 680 * them there for userspace to be visible... */ 681 if (sb->s_op->sync_fs) 682 sb->s_op->sync_fs(sb, 1); 683 sync_blockdev(sb->s_bdev); 684 685 /* 686 * Now when everything is written we can discard the pagecache so 687 * that userspace sees the changes. 688 */ 689 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 690 if (type != -1 && cnt != type) 691 continue; 692 if (!sb_has_quota_active(sb, cnt)) 693 continue; 694 inode_lock(dqopt->files[cnt]); 695 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 696 inode_unlock(dqopt->files[cnt]); 697 } 698 699 return 0; 700 } 701 EXPORT_SYMBOL(dquot_quota_sync); 702 703 static unsigned long 704 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 705 { 706 struct list_head *head; 707 struct dquot *dquot; 708 unsigned long freed = 0; 709 710 spin_lock(&dq_list_lock); 711 head = free_dquots.prev; 712 while (head != &free_dquots && sc->nr_to_scan) { 713 dquot = list_entry(head, struct dquot, dq_free); 714 remove_dquot_hash(dquot); 715 remove_free_dquot(dquot); 716 remove_inuse(dquot); 717 do_destroy_dquot(dquot); 718 sc->nr_to_scan--; 719 freed++; 720 head = free_dquots.prev; 721 } 722 spin_unlock(&dq_list_lock); 723 return freed; 724 } 725 726 static unsigned long 727 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 728 { 729 return vfs_pressure_ratio( 730 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 731 } 732 733 static struct shrinker dqcache_shrinker = { 734 .count_objects = dqcache_shrink_count, 735 .scan_objects = dqcache_shrink_scan, 736 .seeks = DEFAULT_SEEKS, 737 }; 738 739 /* 740 * Put reference to dquot 741 */ 742 void dqput(struct dquot *dquot) 743 { 744 int ret; 745 746 if (!dquot) 747 return; 748 #ifdef CONFIG_QUOTA_DEBUG 749 if (!atomic_read(&dquot->dq_count)) { 750 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 751 quotatypes[dquot->dq_id.type], 752 from_kqid(&init_user_ns, dquot->dq_id)); 753 BUG(); 754 } 755 #endif 756 dqstats_inc(DQST_DROPS); 757 we_slept: 758 spin_lock(&dq_list_lock); 759 if (atomic_read(&dquot->dq_count) > 1) { 760 /* We have more than one user... nothing to do */ 761 atomic_dec(&dquot->dq_count); 762 /* Releasing dquot during quotaoff phase? */ 763 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 764 atomic_read(&dquot->dq_count) == 1) 765 wake_up(&dquot_ref_wq); 766 spin_unlock(&dq_list_lock); 767 return; 768 } 769 /* Need to release dquot? */ 770 if (dquot_dirty(dquot)) { 771 spin_unlock(&dq_list_lock); 772 /* Commit dquot before releasing */ 773 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 774 if (ret < 0) { 775 quota_error(dquot->dq_sb, "Can't write quota structure" 776 " (error %d). Quota may get out of sync!", 777 ret); 778 /* 779 * We clear dirty bit anyway, so that we avoid 780 * infinite loop here 781 */ 782 clear_dquot_dirty(dquot); 783 } 784 goto we_slept; 785 } 786 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 787 spin_unlock(&dq_list_lock); 788 dquot->dq_sb->dq_op->release_dquot(dquot); 789 goto we_slept; 790 } 791 atomic_dec(&dquot->dq_count); 792 #ifdef CONFIG_QUOTA_DEBUG 793 /* sanity check */ 794 BUG_ON(!list_empty(&dquot->dq_free)); 795 #endif 796 put_dquot_last(dquot); 797 spin_unlock(&dq_list_lock); 798 } 799 EXPORT_SYMBOL(dqput); 800 801 struct dquot *dquot_alloc(struct super_block *sb, int type) 802 { 803 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 804 } 805 EXPORT_SYMBOL(dquot_alloc); 806 807 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 808 { 809 struct dquot *dquot; 810 811 dquot = sb->dq_op->alloc_dquot(sb, type); 812 if(!dquot) 813 return NULL; 814 815 mutex_init(&dquot->dq_lock); 816 INIT_LIST_HEAD(&dquot->dq_free); 817 INIT_LIST_HEAD(&dquot->dq_inuse); 818 INIT_HLIST_NODE(&dquot->dq_hash); 819 INIT_LIST_HEAD(&dquot->dq_dirty); 820 dquot->dq_sb = sb; 821 dquot->dq_id = make_kqid_invalid(type); 822 atomic_set(&dquot->dq_count, 1); 823 spin_lock_init(&dquot->dq_dqb_lock); 824 825 return dquot; 826 } 827 828 /* 829 * Get reference to dquot 830 * 831 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 832 * destroying our dquot by: 833 * a) checking for quota flags under dq_list_lock and 834 * b) getting a reference to dquot before we release dq_list_lock 835 */ 836 struct dquot *dqget(struct super_block *sb, struct kqid qid) 837 { 838 unsigned int hashent = hashfn(sb, qid); 839 struct dquot *dquot, *empty = NULL; 840 841 if (!qid_has_mapping(sb->s_user_ns, qid)) 842 return ERR_PTR(-EINVAL); 843 844 if (!sb_has_quota_active(sb, qid.type)) 845 return ERR_PTR(-ESRCH); 846 we_slept: 847 spin_lock(&dq_list_lock); 848 spin_lock(&dq_state_lock); 849 if (!sb_has_quota_active(sb, qid.type)) { 850 spin_unlock(&dq_state_lock); 851 spin_unlock(&dq_list_lock); 852 dquot = ERR_PTR(-ESRCH); 853 goto out; 854 } 855 spin_unlock(&dq_state_lock); 856 857 dquot = find_dquot(hashent, sb, qid); 858 if (!dquot) { 859 if (!empty) { 860 spin_unlock(&dq_list_lock); 861 empty = get_empty_dquot(sb, qid.type); 862 if (!empty) 863 schedule(); /* Try to wait for a moment... */ 864 goto we_slept; 865 } 866 dquot = empty; 867 empty = NULL; 868 dquot->dq_id = qid; 869 /* all dquots go on the inuse_list */ 870 put_inuse(dquot); 871 /* hash it first so it can be found */ 872 insert_dquot_hash(dquot); 873 spin_unlock(&dq_list_lock); 874 dqstats_inc(DQST_LOOKUPS); 875 } else { 876 if (!atomic_read(&dquot->dq_count)) 877 remove_free_dquot(dquot); 878 atomic_inc(&dquot->dq_count); 879 spin_unlock(&dq_list_lock); 880 dqstats_inc(DQST_CACHE_HITS); 881 dqstats_inc(DQST_LOOKUPS); 882 } 883 /* Wait for dq_lock - after this we know that either dquot_release() is 884 * already finished or it will be canceled due to dq_count > 1 test */ 885 wait_on_dquot(dquot); 886 /* Read the dquot / allocate space in quota file */ 887 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 888 int err; 889 890 err = sb->dq_op->acquire_dquot(dquot); 891 if (err < 0) { 892 dqput(dquot); 893 dquot = ERR_PTR(err); 894 goto out; 895 } 896 } 897 /* 898 * Make sure following reads see filled structure - paired with 899 * smp_mb__before_atomic() in dquot_acquire(). 900 */ 901 smp_rmb(); 902 #ifdef CONFIG_QUOTA_DEBUG 903 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 904 #endif 905 out: 906 if (empty) 907 do_destroy_dquot(empty); 908 909 return dquot; 910 } 911 EXPORT_SYMBOL(dqget); 912 913 static inline struct dquot **i_dquot(struct inode *inode) 914 { 915 return inode->i_sb->s_op->get_dquots(inode); 916 } 917 918 static int dqinit_needed(struct inode *inode, int type) 919 { 920 struct dquot * const *dquots; 921 int cnt; 922 923 if (IS_NOQUOTA(inode)) 924 return 0; 925 926 dquots = i_dquot(inode); 927 if (type != -1) 928 return !dquots[type]; 929 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 930 if (!dquots[cnt]) 931 return 1; 932 return 0; 933 } 934 935 /* This routine is guarded by s_umount semaphore */ 936 static void add_dquot_ref(struct super_block *sb, int type) 937 { 938 struct inode *inode, *old_inode = NULL; 939 #ifdef CONFIG_QUOTA_DEBUG 940 int reserved = 0; 941 #endif 942 943 spin_lock(&sb->s_inode_list_lock); 944 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 945 spin_lock(&inode->i_lock); 946 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 947 !atomic_read(&inode->i_writecount) || 948 !dqinit_needed(inode, type)) { 949 spin_unlock(&inode->i_lock); 950 continue; 951 } 952 __iget(inode); 953 spin_unlock(&inode->i_lock); 954 spin_unlock(&sb->s_inode_list_lock); 955 956 #ifdef CONFIG_QUOTA_DEBUG 957 if (unlikely(inode_get_rsv_space(inode) > 0)) 958 reserved = 1; 959 #endif 960 iput(old_inode); 961 __dquot_initialize(inode, type); 962 963 /* 964 * We hold a reference to 'inode' so it couldn't have been 965 * removed from s_inodes list while we dropped the 966 * s_inode_list_lock. We cannot iput the inode now as we can be 967 * holding the last reference and we cannot iput it under 968 * s_inode_list_lock. So we keep the reference and iput it 969 * later. 970 */ 971 old_inode = inode; 972 spin_lock(&sb->s_inode_list_lock); 973 } 974 spin_unlock(&sb->s_inode_list_lock); 975 iput(old_inode); 976 977 #ifdef CONFIG_QUOTA_DEBUG 978 if (reserved) { 979 quota_error(sb, "Writes happened before quota was turned on " 980 "thus quota information is probably inconsistent. " 981 "Please run quotacheck(8)"); 982 } 983 #endif 984 } 985 986 /* 987 * Remove references to dquots from inode and add dquot to list for freeing 988 * if we have the last reference to dquot 989 */ 990 static void remove_inode_dquot_ref(struct inode *inode, int type, 991 struct list_head *tofree_head) 992 { 993 struct dquot **dquots = i_dquot(inode); 994 struct dquot *dquot = dquots[type]; 995 996 if (!dquot) 997 return; 998 999 dquots[type] = NULL; 1000 if (list_empty(&dquot->dq_free)) { 1001 /* 1002 * The inode still has reference to dquot so it can't be in the 1003 * free list 1004 */ 1005 spin_lock(&dq_list_lock); 1006 list_add(&dquot->dq_free, tofree_head); 1007 spin_unlock(&dq_list_lock); 1008 } else { 1009 /* 1010 * Dquot is already in a list to put so we won't drop the last 1011 * reference here. 1012 */ 1013 dqput(dquot); 1014 } 1015 } 1016 1017 /* 1018 * Free list of dquots 1019 * Dquots are removed from inodes and no new references can be got so we are 1020 * the only ones holding reference 1021 */ 1022 static void put_dquot_list(struct list_head *tofree_head) 1023 { 1024 struct list_head *act_head; 1025 struct dquot *dquot; 1026 1027 act_head = tofree_head->next; 1028 while (act_head != tofree_head) { 1029 dquot = list_entry(act_head, struct dquot, dq_free); 1030 act_head = act_head->next; 1031 /* Remove dquot from the list so we won't have problems... */ 1032 list_del_init(&dquot->dq_free); 1033 dqput(dquot); 1034 } 1035 } 1036 1037 static void remove_dquot_ref(struct super_block *sb, int type, 1038 struct list_head *tofree_head) 1039 { 1040 struct inode *inode; 1041 int reserved = 0; 1042 1043 spin_lock(&sb->s_inode_list_lock); 1044 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1045 /* 1046 * We have to scan also I_NEW inodes because they can already 1047 * have quota pointer initialized. Luckily, we need to touch 1048 * only quota pointers and these have separate locking 1049 * (dq_data_lock). 1050 */ 1051 spin_lock(&dq_data_lock); 1052 if (!IS_NOQUOTA(inode)) { 1053 if (unlikely(inode_get_rsv_space(inode) > 0)) 1054 reserved = 1; 1055 remove_inode_dquot_ref(inode, type, tofree_head); 1056 } 1057 spin_unlock(&dq_data_lock); 1058 } 1059 spin_unlock(&sb->s_inode_list_lock); 1060 #ifdef CONFIG_QUOTA_DEBUG 1061 if (reserved) { 1062 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1063 " was disabled thus quota information is probably " 1064 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1065 } 1066 #endif 1067 } 1068 1069 /* Gather all references from inodes and drop them */ 1070 static void drop_dquot_ref(struct super_block *sb, int type) 1071 { 1072 LIST_HEAD(tofree_head); 1073 1074 if (sb->dq_op) { 1075 remove_dquot_ref(sb, type, &tofree_head); 1076 synchronize_srcu(&dquot_srcu); 1077 put_dquot_list(&tofree_head); 1078 } 1079 } 1080 1081 static inline 1082 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1083 { 1084 if (dquot->dq_dqb.dqb_rsvspace >= number) 1085 dquot->dq_dqb.dqb_rsvspace -= number; 1086 else { 1087 WARN_ON_ONCE(1); 1088 dquot->dq_dqb.dqb_rsvspace = 0; 1089 } 1090 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1091 dquot->dq_dqb.dqb_bsoftlimit) 1092 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1093 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1094 } 1095 1096 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1097 { 1098 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1099 dquot->dq_dqb.dqb_curinodes >= number) 1100 dquot->dq_dqb.dqb_curinodes -= number; 1101 else 1102 dquot->dq_dqb.dqb_curinodes = 0; 1103 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1104 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1105 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1106 } 1107 1108 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1109 { 1110 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1111 dquot->dq_dqb.dqb_curspace >= number) 1112 dquot->dq_dqb.dqb_curspace -= number; 1113 else 1114 dquot->dq_dqb.dqb_curspace = 0; 1115 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1116 dquot->dq_dqb.dqb_bsoftlimit) 1117 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1118 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1119 } 1120 1121 struct dquot_warn { 1122 struct super_block *w_sb; 1123 struct kqid w_dq_id; 1124 short w_type; 1125 }; 1126 1127 static int warning_issued(struct dquot *dquot, const int warntype) 1128 { 1129 int flag = (warntype == QUOTA_NL_BHARDWARN || 1130 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1131 ((warntype == QUOTA_NL_IHARDWARN || 1132 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1133 1134 if (!flag) 1135 return 0; 1136 return test_and_set_bit(flag, &dquot->dq_flags); 1137 } 1138 1139 #ifdef CONFIG_PRINT_QUOTA_WARNING 1140 static int flag_print_warnings = 1; 1141 1142 static int need_print_warning(struct dquot_warn *warn) 1143 { 1144 if (!flag_print_warnings) 1145 return 0; 1146 1147 switch (warn->w_dq_id.type) { 1148 case USRQUOTA: 1149 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1150 case GRPQUOTA: 1151 return in_group_p(warn->w_dq_id.gid); 1152 case PRJQUOTA: 1153 return 1; 1154 } 1155 return 0; 1156 } 1157 1158 /* Print warning to user which exceeded quota */ 1159 static void print_warning(struct dquot_warn *warn) 1160 { 1161 char *msg = NULL; 1162 struct tty_struct *tty; 1163 int warntype = warn->w_type; 1164 1165 if (warntype == QUOTA_NL_IHARDBELOW || 1166 warntype == QUOTA_NL_ISOFTBELOW || 1167 warntype == QUOTA_NL_BHARDBELOW || 1168 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1169 return; 1170 1171 tty = get_current_tty(); 1172 if (!tty) 1173 return; 1174 tty_write_message(tty, warn->w_sb->s_id); 1175 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1176 tty_write_message(tty, ": warning, "); 1177 else 1178 tty_write_message(tty, ": write failed, "); 1179 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1180 switch (warntype) { 1181 case QUOTA_NL_IHARDWARN: 1182 msg = " file limit reached.\r\n"; 1183 break; 1184 case QUOTA_NL_ISOFTLONGWARN: 1185 msg = " file quota exceeded too long.\r\n"; 1186 break; 1187 case QUOTA_NL_ISOFTWARN: 1188 msg = " file quota exceeded.\r\n"; 1189 break; 1190 case QUOTA_NL_BHARDWARN: 1191 msg = " block limit reached.\r\n"; 1192 break; 1193 case QUOTA_NL_BSOFTLONGWARN: 1194 msg = " block quota exceeded too long.\r\n"; 1195 break; 1196 case QUOTA_NL_BSOFTWARN: 1197 msg = " block quota exceeded.\r\n"; 1198 break; 1199 } 1200 tty_write_message(tty, msg); 1201 tty_kref_put(tty); 1202 } 1203 #endif 1204 1205 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1206 int warntype) 1207 { 1208 if (warning_issued(dquot, warntype)) 1209 return; 1210 warn->w_type = warntype; 1211 warn->w_sb = dquot->dq_sb; 1212 warn->w_dq_id = dquot->dq_id; 1213 } 1214 1215 /* 1216 * Write warnings to the console and send warning messages over netlink. 1217 * 1218 * Note that this function can call into tty and networking code. 1219 */ 1220 static void flush_warnings(struct dquot_warn *warn) 1221 { 1222 int i; 1223 1224 for (i = 0; i < MAXQUOTAS; i++) { 1225 if (warn[i].w_type == QUOTA_NL_NOWARN) 1226 continue; 1227 #ifdef CONFIG_PRINT_QUOTA_WARNING 1228 print_warning(&warn[i]); 1229 #endif 1230 quota_send_warning(warn[i].w_dq_id, 1231 warn[i].w_sb->s_dev, warn[i].w_type); 1232 } 1233 } 1234 1235 static int ignore_hardlimit(struct dquot *dquot) 1236 { 1237 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1238 1239 return capable(CAP_SYS_RESOURCE) && 1240 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1241 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1242 } 1243 1244 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1245 struct dquot_warn *warn) 1246 { 1247 qsize_t newinodes; 1248 int ret = 0; 1249 1250 spin_lock(&dquot->dq_dqb_lock); 1251 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1252 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1253 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1254 goto add; 1255 1256 if (dquot->dq_dqb.dqb_ihardlimit && 1257 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1258 !ignore_hardlimit(dquot)) { 1259 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1260 ret = -EDQUOT; 1261 goto out; 1262 } 1263 1264 if (dquot->dq_dqb.dqb_isoftlimit && 1265 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1266 dquot->dq_dqb.dqb_itime && 1267 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1268 !ignore_hardlimit(dquot)) { 1269 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1270 ret = -EDQUOT; 1271 goto out; 1272 } 1273 1274 if (dquot->dq_dqb.dqb_isoftlimit && 1275 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1276 dquot->dq_dqb.dqb_itime == 0) { 1277 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1278 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1279 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1280 } 1281 add: 1282 dquot->dq_dqb.dqb_curinodes = newinodes; 1283 1284 out: 1285 spin_unlock(&dquot->dq_dqb_lock); 1286 return ret; 1287 } 1288 1289 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1290 qsize_t rsv_space, unsigned int flags, 1291 struct dquot_warn *warn) 1292 { 1293 qsize_t tspace; 1294 struct super_block *sb = dquot->dq_sb; 1295 int ret = 0; 1296 1297 spin_lock(&dquot->dq_dqb_lock); 1298 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1299 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1300 goto finish; 1301 1302 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1303 + space + rsv_space; 1304 1305 if (dquot->dq_dqb.dqb_bhardlimit && 1306 tspace > dquot->dq_dqb.dqb_bhardlimit && 1307 !ignore_hardlimit(dquot)) { 1308 if (flags & DQUOT_SPACE_WARN) 1309 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1310 ret = -EDQUOT; 1311 goto finish; 1312 } 1313 1314 if (dquot->dq_dqb.dqb_bsoftlimit && 1315 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1316 dquot->dq_dqb.dqb_btime && 1317 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1318 !ignore_hardlimit(dquot)) { 1319 if (flags & DQUOT_SPACE_WARN) 1320 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1321 ret = -EDQUOT; 1322 goto finish; 1323 } 1324 1325 if (dquot->dq_dqb.dqb_bsoftlimit && 1326 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1327 dquot->dq_dqb.dqb_btime == 0) { 1328 if (flags & DQUOT_SPACE_WARN) { 1329 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1330 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1331 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1332 } else { 1333 /* 1334 * We don't allow preallocation to exceed softlimit so exceeding will 1335 * be always printed 1336 */ 1337 ret = -EDQUOT; 1338 goto finish; 1339 } 1340 } 1341 finish: 1342 /* 1343 * We have to be careful and go through warning generation & grace time 1344 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1345 * only here... 1346 */ 1347 if (flags & DQUOT_SPACE_NOFAIL) 1348 ret = 0; 1349 if (!ret) { 1350 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1351 dquot->dq_dqb.dqb_curspace += space; 1352 } 1353 spin_unlock(&dquot->dq_dqb_lock); 1354 return ret; 1355 } 1356 1357 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1358 { 1359 qsize_t newinodes; 1360 1361 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1362 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1363 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1364 return QUOTA_NL_NOWARN; 1365 1366 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1367 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1368 return QUOTA_NL_ISOFTBELOW; 1369 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1370 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1371 return QUOTA_NL_IHARDBELOW; 1372 return QUOTA_NL_NOWARN; 1373 } 1374 1375 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1376 { 1377 qsize_t tspace; 1378 1379 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1380 1381 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1382 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1383 return QUOTA_NL_NOWARN; 1384 1385 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1386 return QUOTA_NL_BSOFTBELOW; 1387 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1388 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1389 return QUOTA_NL_BHARDBELOW; 1390 return QUOTA_NL_NOWARN; 1391 } 1392 1393 static int dquot_active(const struct inode *inode) 1394 { 1395 struct super_block *sb = inode->i_sb; 1396 1397 if (IS_NOQUOTA(inode)) 1398 return 0; 1399 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1400 } 1401 1402 /* 1403 * Initialize quota pointers in inode 1404 * 1405 * It is better to call this function outside of any transaction as it 1406 * might need a lot of space in journal for dquot structure allocation. 1407 */ 1408 static int __dquot_initialize(struct inode *inode, int type) 1409 { 1410 int cnt, init_needed = 0; 1411 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1412 struct super_block *sb = inode->i_sb; 1413 qsize_t rsv; 1414 int ret = 0; 1415 1416 if (!dquot_active(inode)) 1417 return 0; 1418 1419 dquots = i_dquot(inode); 1420 1421 /* First get references to structures we might need. */ 1422 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1423 struct kqid qid; 1424 kprojid_t projid; 1425 int rc; 1426 struct dquot *dquot; 1427 1428 if (type != -1 && cnt != type) 1429 continue; 1430 /* 1431 * The i_dquot should have been initialized in most cases, 1432 * we check it without locking here to avoid unnecessary 1433 * dqget()/dqput() calls. 1434 */ 1435 if (dquots[cnt]) 1436 continue; 1437 1438 if (!sb_has_quota_active(sb, cnt)) 1439 continue; 1440 1441 init_needed = 1; 1442 1443 switch (cnt) { 1444 case USRQUOTA: 1445 qid = make_kqid_uid(inode->i_uid); 1446 break; 1447 case GRPQUOTA: 1448 qid = make_kqid_gid(inode->i_gid); 1449 break; 1450 case PRJQUOTA: 1451 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1452 if (rc) 1453 continue; 1454 qid = make_kqid_projid(projid); 1455 break; 1456 } 1457 dquot = dqget(sb, qid); 1458 if (IS_ERR(dquot)) { 1459 /* We raced with somebody turning quotas off... */ 1460 if (PTR_ERR(dquot) != -ESRCH) { 1461 ret = PTR_ERR(dquot); 1462 goto out_put; 1463 } 1464 dquot = NULL; 1465 } 1466 got[cnt] = dquot; 1467 } 1468 1469 /* All required i_dquot has been initialized */ 1470 if (!init_needed) 1471 return 0; 1472 1473 spin_lock(&dq_data_lock); 1474 if (IS_NOQUOTA(inode)) 1475 goto out_lock; 1476 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1477 if (type != -1 && cnt != type) 1478 continue; 1479 /* Avoid races with quotaoff() */ 1480 if (!sb_has_quota_active(sb, cnt)) 1481 continue; 1482 /* We could race with quotaon or dqget() could have failed */ 1483 if (!got[cnt]) 1484 continue; 1485 if (!dquots[cnt]) { 1486 dquots[cnt] = got[cnt]; 1487 got[cnt] = NULL; 1488 /* 1489 * Make quota reservation system happy if someone 1490 * did a write before quota was turned on 1491 */ 1492 rsv = inode_get_rsv_space(inode); 1493 if (unlikely(rsv)) { 1494 spin_lock(&inode->i_lock); 1495 /* Get reservation again under proper lock */ 1496 rsv = __inode_get_rsv_space(inode); 1497 spin_lock(&dquots[cnt]->dq_dqb_lock); 1498 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1499 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1500 spin_unlock(&inode->i_lock); 1501 } 1502 } 1503 } 1504 out_lock: 1505 spin_unlock(&dq_data_lock); 1506 out_put: 1507 /* Drop unused references */ 1508 dqput_all(got); 1509 1510 return ret; 1511 } 1512 1513 int dquot_initialize(struct inode *inode) 1514 { 1515 return __dquot_initialize(inode, -1); 1516 } 1517 EXPORT_SYMBOL(dquot_initialize); 1518 1519 bool dquot_initialize_needed(struct inode *inode) 1520 { 1521 struct dquot **dquots; 1522 int i; 1523 1524 if (!dquot_active(inode)) 1525 return false; 1526 1527 dquots = i_dquot(inode); 1528 for (i = 0; i < MAXQUOTAS; i++) 1529 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1530 return true; 1531 return false; 1532 } 1533 EXPORT_SYMBOL(dquot_initialize_needed); 1534 1535 /* 1536 * Release all quotas referenced by inode. 1537 * 1538 * This function only be called on inode free or converting 1539 * a file to quota file, no other users for the i_dquot in 1540 * both cases, so we needn't call synchronize_srcu() after 1541 * clearing i_dquot. 1542 */ 1543 static void __dquot_drop(struct inode *inode) 1544 { 1545 int cnt; 1546 struct dquot **dquots = i_dquot(inode); 1547 struct dquot *put[MAXQUOTAS]; 1548 1549 spin_lock(&dq_data_lock); 1550 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1551 put[cnt] = dquots[cnt]; 1552 dquots[cnt] = NULL; 1553 } 1554 spin_unlock(&dq_data_lock); 1555 dqput_all(put); 1556 } 1557 1558 void dquot_drop(struct inode *inode) 1559 { 1560 struct dquot * const *dquots; 1561 int cnt; 1562 1563 if (IS_NOQUOTA(inode)) 1564 return; 1565 1566 /* 1567 * Test before calling to rule out calls from proc and such 1568 * where we are not allowed to block. Note that this is 1569 * actually reliable test even without the lock - the caller 1570 * must assure that nobody can come after the DQUOT_DROP and 1571 * add quota pointers back anyway. 1572 */ 1573 dquots = i_dquot(inode); 1574 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1575 if (dquots[cnt]) 1576 break; 1577 } 1578 1579 if (cnt < MAXQUOTAS) 1580 __dquot_drop(inode); 1581 } 1582 EXPORT_SYMBOL(dquot_drop); 1583 1584 /* 1585 * inode_reserved_space is managed internally by quota, and protected by 1586 * i_lock similar to i_blocks+i_bytes. 1587 */ 1588 static qsize_t *inode_reserved_space(struct inode * inode) 1589 { 1590 /* Filesystem must explicitly define it's own method in order to use 1591 * quota reservation interface */ 1592 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1593 return inode->i_sb->dq_op->get_reserved_space(inode); 1594 } 1595 1596 static qsize_t __inode_get_rsv_space(struct inode *inode) 1597 { 1598 if (!inode->i_sb->dq_op->get_reserved_space) 1599 return 0; 1600 return *inode_reserved_space(inode); 1601 } 1602 1603 static qsize_t inode_get_rsv_space(struct inode *inode) 1604 { 1605 qsize_t ret; 1606 1607 if (!inode->i_sb->dq_op->get_reserved_space) 1608 return 0; 1609 spin_lock(&inode->i_lock); 1610 ret = __inode_get_rsv_space(inode); 1611 spin_unlock(&inode->i_lock); 1612 return ret; 1613 } 1614 1615 /* 1616 * This functions updates i_blocks+i_bytes fields and quota information 1617 * (together with appropriate checks). 1618 * 1619 * NOTE: We absolutely rely on the fact that caller dirties the inode 1620 * (usually helpers in quotaops.h care about this) and holds a handle for 1621 * the current transaction so that dquot write and inode write go into the 1622 * same transaction. 1623 */ 1624 1625 /* 1626 * This operation can block, but only after everything is updated 1627 */ 1628 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1629 { 1630 int cnt, ret = 0, index; 1631 struct dquot_warn warn[MAXQUOTAS]; 1632 int reserve = flags & DQUOT_SPACE_RESERVE; 1633 struct dquot **dquots; 1634 1635 if (!dquot_active(inode)) { 1636 if (reserve) { 1637 spin_lock(&inode->i_lock); 1638 *inode_reserved_space(inode) += number; 1639 spin_unlock(&inode->i_lock); 1640 } else { 1641 inode_add_bytes(inode, number); 1642 } 1643 goto out; 1644 } 1645 1646 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1647 warn[cnt].w_type = QUOTA_NL_NOWARN; 1648 1649 dquots = i_dquot(inode); 1650 index = srcu_read_lock(&dquot_srcu); 1651 spin_lock(&inode->i_lock); 1652 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1653 if (!dquots[cnt]) 1654 continue; 1655 if (flags & DQUOT_SPACE_RESERVE) { 1656 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1657 &warn[cnt]); 1658 } else { 1659 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1660 &warn[cnt]); 1661 } 1662 if (ret) { 1663 /* Back out changes we already did */ 1664 for (cnt--; cnt >= 0; cnt--) { 1665 if (!dquots[cnt]) 1666 continue; 1667 spin_lock(&dquots[cnt]->dq_dqb_lock); 1668 if (flags & DQUOT_SPACE_RESERVE) { 1669 dquots[cnt]->dq_dqb.dqb_rsvspace -= 1670 number; 1671 } else { 1672 dquots[cnt]->dq_dqb.dqb_curspace -= 1673 number; 1674 } 1675 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1676 } 1677 spin_unlock(&inode->i_lock); 1678 goto out_flush_warn; 1679 } 1680 } 1681 if (reserve) 1682 *inode_reserved_space(inode) += number; 1683 else 1684 __inode_add_bytes(inode, number); 1685 spin_unlock(&inode->i_lock); 1686 1687 if (reserve) 1688 goto out_flush_warn; 1689 mark_all_dquot_dirty(dquots); 1690 out_flush_warn: 1691 srcu_read_unlock(&dquot_srcu, index); 1692 flush_warnings(warn); 1693 out: 1694 return ret; 1695 } 1696 EXPORT_SYMBOL(__dquot_alloc_space); 1697 1698 /* 1699 * This operation can block, but only after everything is updated 1700 */ 1701 int dquot_alloc_inode(struct inode *inode) 1702 { 1703 int cnt, ret = 0, index; 1704 struct dquot_warn warn[MAXQUOTAS]; 1705 struct dquot * const *dquots; 1706 1707 if (!dquot_active(inode)) 1708 return 0; 1709 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1710 warn[cnt].w_type = QUOTA_NL_NOWARN; 1711 1712 dquots = i_dquot(inode); 1713 index = srcu_read_lock(&dquot_srcu); 1714 spin_lock(&inode->i_lock); 1715 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1716 if (!dquots[cnt]) 1717 continue; 1718 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1719 if (ret) { 1720 for (cnt--; cnt >= 0; cnt--) { 1721 if (!dquots[cnt]) 1722 continue; 1723 /* Back out changes we already did */ 1724 spin_lock(&dquots[cnt]->dq_dqb_lock); 1725 dquots[cnt]->dq_dqb.dqb_curinodes--; 1726 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1727 } 1728 goto warn_put_all; 1729 } 1730 } 1731 1732 warn_put_all: 1733 spin_unlock(&inode->i_lock); 1734 if (ret == 0) 1735 mark_all_dquot_dirty(dquots); 1736 srcu_read_unlock(&dquot_srcu, index); 1737 flush_warnings(warn); 1738 return ret; 1739 } 1740 EXPORT_SYMBOL(dquot_alloc_inode); 1741 1742 /* 1743 * Convert in-memory reserved quotas to real consumed quotas 1744 */ 1745 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1746 { 1747 struct dquot **dquots; 1748 int cnt, index; 1749 1750 if (!dquot_active(inode)) { 1751 spin_lock(&inode->i_lock); 1752 *inode_reserved_space(inode) -= number; 1753 __inode_add_bytes(inode, number); 1754 spin_unlock(&inode->i_lock); 1755 return 0; 1756 } 1757 1758 dquots = i_dquot(inode); 1759 index = srcu_read_lock(&dquot_srcu); 1760 spin_lock(&inode->i_lock); 1761 /* Claim reserved quotas to allocated quotas */ 1762 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1763 if (dquots[cnt]) { 1764 struct dquot *dquot = dquots[cnt]; 1765 1766 spin_lock(&dquot->dq_dqb_lock); 1767 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1768 number = dquot->dq_dqb.dqb_rsvspace; 1769 dquot->dq_dqb.dqb_curspace += number; 1770 dquot->dq_dqb.dqb_rsvspace -= number; 1771 spin_unlock(&dquot->dq_dqb_lock); 1772 } 1773 } 1774 /* Update inode bytes */ 1775 *inode_reserved_space(inode) -= number; 1776 __inode_add_bytes(inode, number); 1777 spin_unlock(&inode->i_lock); 1778 mark_all_dquot_dirty(dquots); 1779 srcu_read_unlock(&dquot_srcu, index); 1780 return 0; 1781 } 1782 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1783 1784 /* 1785 * Convert allocated space back to in-memory reserved quotas 1786 */ 1787 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1788 { 1789 struct dquot **dquots; 1790 int cnt, index; 1791 1792 if (!dquot_active(inode)) { 1793 spin_lock(&inode->i_lock); 1794 *inode_reserved_space(inode) += number; 1795 __inode_sub_bytes(inode, number); 1796 spin_unlock(&inode->i_lock); 1797 return; 1798 } 1799 1800 dquots = i_dquot(inode); 1801 index = srcu_read_lock(&dquot_srcu); 1802 spin_lock(&inode->i_lock); 1803 /* Claim reserved quotas to allocated quotas */ 1804 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1805 if (dquots[cnt]) { 1806 struct dquot *dquot = dquots[cnt]; 1807 1808 spin_lock(&dquot->dq_dqb_lock); 1809 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1810 number = dquot->dq_dqb.dqb_curspace; 1811 dquot->dq_dqb.dqb_rsvspace += number; 1812 dquot->dq_dqb.dqb_curspace -= number; 1813 spin_unlock(&dquot->dq_dqb_lock); 1814 } 1815 } 1816 /* Update inode bytes */ 1817 *inode_reserved_space(inode) += number; 1818 __inode_sub_bytes(inode, number); 1819 spin_unlock(&inode->i_lock); 1820 mark_all_dquot_dirty(dquots); 1821 srcu_read_unlock(&dquot_srcu, index); 1822 return; 1823 } 1824 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1825 1826 /* 1827 * This operation can block, but only after everything is updated 1828 */ 1829 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1830 { 1831 unsigned int cnt; 1832 struct dquot_warn warn[MAXQUOTAS]; 1833 struct dquot **dquots; 1834 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1835 1836 if (!dquot_active(inode)) { 1837 if (reserve) { 1838 spin_lock(&inode->i_lock); 1839 *inode_reserved_space(inode) -= number; 1840 spin_unlock(&inode->i_lock); 1841 } else { 1842 inode_sub_bytes(inode, number); 1843 } 1844 return; 1845 } 1846 1847 dquots = i_dquot(inode); 1848 index = srcu_read_lock(&dquot_srcu); 1849 spin_lock(&inode->i_lock); 1850 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1851 int wtype; 1852 1853 warn[cnt].w_type = QUOTA_NL_NOWARN; 1854 if (!dquots[cnt]) 1855 continue; 1856 spin_lock(&dquots[cnt]->dq_dqb_lock); 1857 wtype = info_bdq_free(dquots[cnt], number); 1858 if (wtype != QUOTA_NL_NOWARN) 1859 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1860 if (reserve) 1861 dquot_free_reserved_space(dquots[cnt], number); 1862 else 1863 dquot_decr_space(dquots[cnt], number); 1864 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1865 } 1866 if (reserve) 1867 *inode_reserved_space(inode) -= number; 1868 else 1869 __inode_sub_bytes(inode, number); 1870 spin_unlock(&inode->i_lock); 1871 1872 if (reserve) 1873 goto out_unlock; 1874 mark_all_dquot_dirty(dquots); 1875 out_unlock: 1876 srcu_read_unlock(&dquot_srcu, index); 1877 flush_warnings(warn); 1878 } 1879 EXPORT_SYMBOL(__dquot_free_space); 1880 1881 /* 1882 * This operation can block, but only after everything is updated 1883 */ 1884 void dquot_free_inode(struct inode *inode) 1885 { 1886 unsigned int cnt; 1887 struct dquot_warn warn[MAXQUOTAS]; 1888 struct dquot * const *dquots; 1889 int index; 1890 1891 if (!dquot_active(inode)) 1892 return; 1893 1894 dquots = i_dquot(inode); 1895 index = srcu_read_lock(&dquot_srcu); 1896 spin_lock(&inode->i_lock); 1897 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1898 int wtype; 1899 1900 warn[cnt].w_type = QUOTA_NL_NOWARN; 1901 if (!dquots[cnt]) 1902 continue; 1903 spin_lock(&dquots[cnt]->dq_dqb_lock); 1904 wtype = info_idq_free(dquots[cnt], 1); 1905 if (wtype != QUOTA_NL_NOWARN) 1906 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1907 dquot_decr_inodes(dquots[cnt], 1); 1908 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1909 } 1910 spin_unlock(&inode->i_lock); 1911 mark_all_dquot_dirty(dquots); 1912 srcu_read_unlock(&dquot_srcu, index); 1913 flush_warnings(warn); 1914 } 1915 EXPORT_SYMBOL(dquot_free_inode); 1916 1917 /* 1918 * Transfer the number of inode and blocks from one diskquota to an other. 1919 * On success, dquot references in transfer_to are consumed and references 1920 * to original dquots that need to be released are placed there. On failure, 1921 * references are kept untouched. 1922 * 1923 * This operation can block, but only after everything is updated 1924 * A transaction must be started when entering this function. 1925 * 1926 * We are holding reference on transfer_from & transfer_to, no need to 1927 * protect them by srcu_read_lock(). 1928 */ 1929 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1930 { 1931 qsize_t cur_space; 1932 qsize_t rsv_space = 0; 1933 qsize_t inode_usage = 1; 1934 struct dquot *transfer_from[MAXQUOTAS] = {}; 1935 int cnt, ret = 0; 1936 char is_valid[MAXQUOTAS] = {}; 1937 struct dquot_warn warn_to[MAXQUOTAS]; 1938 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1939 struct dquot_warn warn_from_space[MAXQUOTAS]; 1940 1941 if (IS_NOQUOTA(inode)) 1942 return 0; 1943 1944 if (inode->i_sb->dq_op->get_inode_usage) { 1945 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1946 if (ret) 1947 return ret; 1948 } 1949 1950 /* Initialize the arrays */ 1951 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1952 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1953 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1954 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1955 } 1956 1957 spin_lock(&dq_data_lock); 1958 spin_lock(&inode->i_lock); 1959 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1960 spin_unlock(&inode->i_lock); 1961 spin_unlock(&dq_data_lock); 1962 return 0; 1963 } 1964 cur_space = __inode_get_bytes(inode); 1965 rsv_space = __inode_get_rsv_space(inode); 1966 /* 1967 * Build the transfer_from list, check limits, and update usage in 1968 * the target structures. 1969 */ 1970 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1971 /* 1972 * Skip changes for same uid or gid or for turned off quota-type. 1973 */ 1974 if (!transfer_to[cnt]) 1975 continue; 1976 /* Avoid races with quotaoff() */ 1977 if (!sb_has_quota_active(inode->i_sb, cnt)) 1978 continue; 1979 is_valid[cnt] = 1; 1980 transfer_from[cnt] = i_dquot(inode)[cnt]; 1981 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 1982 &warn_to[cnt]); 1983 if (ret) 1984 goto over_quota; 1985 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 0, 1986 &warn_to[cnt]); 1987 if (ret) { 1988 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 1989 dquot_decr_inodes(transfer_to[cnt], inode_usage); 1990 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 1991 goto over_quota; 1992 } 1993 } 1994 1995 /* Decrease usage for source structures and update quota pointers */ 1996 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1997 if (!is_valid[cnt]) 1998 continue; 1999 /* Due to IO error we might not have transfer_from[] structure */ 2000 if (transfer_from[cnt]) { 2001 int wtype; 2002 2003 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2004 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2005 if (wtype != QUOTA_NL_NOWARN) 2006 prepare_warning(&warn_from_inodes[cnt], 2007 transfer_from[cnt], wtype); 2008 wtype = info_bdq_free(transfer_from[cnt], 2009 cur_space + rsv_space); 2010 if (wtype != QUOTA_NL_NOWARN) 2011 prepare_warning(&warn_from_space[cnt], 2012 transfer_from[cnt], wtype); 2013 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2014 dquot_decr_space(transfer_from[cnt], cur_space); 2015 dquot_free_reserved_space(transfer_from[cnt], 2016 rsv_space); 2017 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2018 } 2019 i_dquot(inode)[cnt] = transfer_to[cnt]; 2020 } 2021 spin_unlock(&inode->i_lock); 2022 spin_unlock(&dq_data_lock); 2023 2024 mark_all_dquot_dirty(transfer_from); 2025 mark_all_dquot_dirty(transfer_to); 2026 flush_warnings(warn_to); 2027 flush_warnings(warn_from_inodes); 2028 flush_warnings(warn_from_space); 2029 /* Pass back references to put */ 2030 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2031 if (is_valid[cnt]) 2032 transfer_to[cnt] = transfer_from[cnt]; 2033 return 0; 2034 over_quota: 2035 /* Back out changes we already did */ 2036 for (cnt--; cnt >= 0; cnt--) { 2037 if (!is_valid[cnt]) 2038 continue; 2039 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2040 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2041 dquot_decr_space(transfer_to[cnt], cur_space); 2042 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2043 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2044 } 2045 spin_unlock(&inode->i_lock); 2046 spin_unlock(&dq_data_lock); 2047 flush_warnings(warn_to); 2048 return ret; 2049 } 2050 EXPORT_SYMBOL(__dquot_transfer); 2051 2052 /* Wrapper for transferring ownership of an inode for uid/gid only 2053 * Called from FSXXX_setattr() 2054 */ 2055 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2056 { 2057 struct dquot *transfer_to[MAXQUOTAS] = {}; 2058 struct dquot *dquot; 2059 struct super_block *sb = inode->i_sb; 2060 int ret; 2061 2062 if (!dquot_active(inode)) 2063 return 0; 2064 2065 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2066 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2067 if (IS_ERR(dquot)) { 2068 if (PTR_ERR(dquot) != -ESRCH) { 2069 ret = PTR_ERR(dquot); 2070 goto out_put; 2071 } 2072 dquot = NULL; 2073 } 2074 transfer_to[USRQUOTA] = dquot; 2075 } 2076 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2077 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2078 if (IS_ERR(dquot)) { 2079 if (PTR_ERR(dquot) != -ESRCH) { 2080 ret = PTR_ERR(dquot); 2081 goto out_put; 2082 } 2083 dquot = NULL; 2084 } 2085 transfer_to[GRPQUOTA] = dquot; 2086 } 2087 ret = __dquot_transfer(inode, transfer_to); 2088 out_put: 2089 dqput_all(transfer_to); 2090 return ret; 2091 } 2092 EXPORT_SYMBOL(dquot_transfer); 2093 2094 /* 2095 * Write info of quota file to disk 2096 */ 2097 int dquot_commit_info(struct super_block *sb, int type) 2098 { 2099 struct quota_info *dqopt = sb_dqopt(sb); 2100 2101 return dqopt->ops[type]->write_file_info(sb, type); 2102 } 2103 EXPORT_SYMBOL(dquot_commit_info); 2104 2105 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2106 { 2107 struct quota_info *dqopt = sb_dqopt(sb); 2108 2109 if (!sb_has_quota_active(sb, qid->type)) 2110 return -ESRCH; 2111 if (!dqopt->ops[qid->type]->get_next_id) 2112 return -ENOSYS; 2113 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2114 } 2115 EXPORT_SYMBOL(dquot_get_next_id); 2116 2117 /* 2118 * Definitions of diskquota operations. 2119 */ 2120 const struct dquot_operations dquot_operations = { 2121 .write_dquot = dquot_commit, 2122 .acquire_dquot = dquot_acquire, 2123 .release_dquot = dquot_release, 2124 .mark_dirty = dquot_mark_dquot_dirty, 2125 .write_info = dquot_commit_info, 2126 .alloc_dquot = dquot_alloc, 2127 .destroy_dquot = dquot_destroy, 2128 .get_next_id = dquot_get_next_id, 2129 }; 2130 EXPORT_SYMBOL(dquot_operations); 2131 2132 /* 2133 * Generic helper for ->open on filesystems supporting disk quotas. 2134 */ 2135 int dquot_file_open(struct inode *inode, struct file *file) 2136 { 2137 int error; 2138 2139 error = generic_file_open(inode, file); 2140 if (!error && (file->f_mode & FMODE_WRITE)) 2141 dquot_initialize(inode); 2142 return error; 2143 } 2144 EXPORT_SYMBOL(dquot_file_open); 2145 2146 /* 2147 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2148 */ 2149 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2150 { 2151 int cnt, ret = 0; 2152 struct quota_info *dqopt = sb_dqopt(sb); 2153 struct inode *toputinode[MAXQUOTAS]; 2154 2155 /* s_umount should be held in exclusive mode */ 2156 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2157 up_read(&sb->s_umount); 2158 2159 /* Cannot turn off usage accounting without turning off limits, or 2160 * suspend quotas and simultaneously turn quotas off. */ 2161 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2162 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2163 DQUOT_USAGE_ENABLED))) 2164 return -EINVAL; 2165 2166 /* 2167 * Skip everything if there's nothing to do. We have to do this because 2168 * sometimes we are called when fill_super() failed and calling 2169 * sync_fs() in such cases does no good. 2170 */ 2171 if (!sb_any_quota_loaded(sb)) 2172 return 0; 2173 2174 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2175 toputinode[cnt] = NULL; 2176 if (type != -1 && cnt != type) 2177 continue; 2178 if (!sb_has_quota_loaded(sb, cnt)) 2179 continue; 2180 2181 if (flags & DQUOT_SUSPENDED) { 2182 spin_lock(&dq_state_lock); 2183 dqopt->flags |= 2184 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2185 spin_unlock(&dq_state_lock); 2186 } else { 2187 spin_lock(&dq_state_lock); 2188 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2189 /* Turning off suspended quotas? */ 2190 if (!sb_has_quota_loaded(sb, cnt) && 2191 sb_has_quota_suspended(sb, cnt)) { 2192 dqopt->flags &= ~dquot_state_flag( 2193 DQUOT_SUSPENDED, cnt); 2194 spin_unlock(&dq_state_lock); 2195 iput(dqopt->files[cnt]); 2196 dqopt->files[cnt] = NULL; 2197 continue; 2198 } 2199 spin_unlock(&dq_state_lock); 2200 } 2201 2202 /* We still have to keep quota loaded? */ 2203 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2204 continue; 2205 2206 /* Note: these are blocking operations */ 2207 drop_dquot_ref(sb, cnt); 2208 invalidate_dquots(sb, cnt); 2209 /* 2210 * Now all dquots should be invalidated, all writes done so we 2211 * should be only users of the info. No locks needed. 2212 */ 2213 if (info_dirty(&dqopt->info[cnt])) 2214 sb->dq_op->write_info(sb, cnt); 2215 if (dqopt->ops[cnt]->free_file_info) 2216 dqopt->ops[cnt]->free_file_info(sb, cnt); 2217 put_quota_format(dqopt->info[cnt].dqi_format); 2218 2219 toputinode[cnt] = dqopt->files[cnt]; 2220 if (!sb_has_quota_loaded(sb, cnt)) 2221 dqopt->files[cnt] = NULL; 2222 dqopt->info[cnt].dqi_flags = 0; 2223 dqopt->info[cnt].dqi_igrace = 0; 2224 dqopt->info[cnt].dqi_bgrace = 0; 2225 dqopt->ops[cnt] = NULL; 2226 } 2227 2228 /* Skip syncing and setting flags if quota files are hidden */ 2229 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2230 goto put_inodes; 2231 2232 /* Sync the superblock so that buffers with quota data are written to 2233 * disk (and so userspace sees correct data afterwards). */ 2234 if (sb->s_op->sync_fs) 2235 sb->s_op->sync_fs(sb, 1); 2236 sync_blockdev(sb->s_bdev); 2237 /* Now the quota files are just ordinary files and we can set the 2238 * inode flags back. Moreover we discard the pagecache so that 2239 * userspace sees the writes we did bypassing the pagecache. We 2240 * must also discard the blockdev buffers so that we see the 2241 * changes done by userspace on the next quotaon() */ 2242 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2243 /* This can happen when suspending quotas on remount-ro... */ 2244 if (toputinode[cnt] && !sb_has_quota_loaded(sb, cnt)) { 2245 inode_lock(toputinode[cnt]); 2246 toputinode[cnt]->i_flags &= ~S_NOQUOTA; 2247 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 2248 inode_unlock(toputinode[cnt]); 2249 mark_inode_dirty_sync(toputinode[cnt]); 2250 } 2251 if (sb->s_bdev) 2252 invalidate_bdev(sb->s_bdev); 2253 put_inodes: 2254 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2255 if (toputinode[cnt]) { 2256 /* On remount RO, we keep the inode pointer so that we 2257 * can reenable quota on the subsequent remount RW. We 2258 * have to check 'flags' variable and not use sb_has_ 2259 * function because another quotaon / quotaoff could 2260 * change global state before we got here. We refuse 2261 * to suspend quotas when there is pending delete on 2262 * the quota file... */ 2263 if (!(flags & DQUOT_SUSPENDED)) 2264 iput(toputinode[cnt]); 2265 else if (!toputinode[cnt]->i_nlink) 2266 ret = -EBUSY; 2267 } 2268 return ret; 2269 } 2270 EXPORT_SYMBOL(dquot_disable); 2271 2272 int dquot_quota_off(struct super_block *sb, int type) 2273 { 2274 return dquot_disable(sb, type, 2275 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2276 } 2277 EXPORT_SYMBOL(dquot_quota_off); 2278 2279 /* 2280 * Turn quotas on on a device 2281 */ 2282 2283 /* 2284 * Helper function to turn quotas on when we already have the inode of 2285 * quota file and no quota information is loaded. 2286 */ 2287 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2288 unsigned int flags) 2289 { 2290 struct quota_format_type *fmt = find_quota_format(format_id); 2291 struct super_block *sb = inode->i_sb; 2292 struct quota_info *dqopt = sb_dqopt(sb); 2293 int error; 2294 2295 if (!fmt) 2296 return -ESRCH; 2297 if (!S_ISREG(inode->i_mode)) { 2298 error = -EACCES; 2299 goto out_fmt; 2300 } 2301 if (IS_RDONLY(inode)) { 2302 error = -EROFS; 2303 goto out_fmt; 2304 } 2305 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2306 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2307 error = -EINVAL; 2308 goto out_fmt; 2309 } 2310 /* Filesystems outside of init_user_ns not yet supported */ 2311 if (sb->s_user_ns != &init_user_ns) { 2312 error = -EINVAL; 2313 goto out_fmt; 2314 } 2315 /* Usage always has to be set... */ 2316 if (!(flags & DQUOT_USAGE_ENABLED)) { 2317 error = -EINVAL; 2318 goto out_fmt; 2319 } 2320 if (sb_has_quota_loaded(sb, type)) { 2321 error = -EBUSY; 2322 goto out_fmt; 2323 } 2324 2325 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2326 /* As we bypass the pagecache we must now flush all the 2327 * dirty data and invalidate caches so that kernel sees 2328 * changes from userspace. It is not enough to just flush 2329 * the quota file since if blocksize < pagesize, invalidation 2330 * of the cache could fail because of other unrelated dirty 2331 * data */ 2332 sync_filesystem(sb); 2333 invalidate_bdev(sb->s_bdev); 2334 } 2335 2336 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2337 /* We don't want quota and atime on quota files (deadlocks 2338 * possible) Also nobody should write to the file - we use 2339 * special IO operations which ignore the immutable bit. */ 2340 inode_lock(inode); 2341 inode->i_flags |= S_NOQUOTA; 2342 inode_unlock(inode); 2343 /* 2344 * When S_NOQUOTA is set, remove dquot references as no more 2345 * references can be added 2346 */ 2347 __dquot_drop(inode); 2348 } 2349 2350 error = -EIO; 2351 dqopt->files[type] = igrab(inode); 2352 if (!dqopt->files[type]) 2353 goto out_file_flags; 2354 error = -EINVAL; 2355 if (!fmt->qf_ops->check_quota_file(sb, type)) 2356 goto out_file_init; 2357 2358 dqopt->ops[type] = fmt->qf_ops; 2359 dqopt->info[type].dqi_format = fmt; 2360 dqopt->info[type].dqi_fmt_id = format_id; 2361 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2362 error = dqopt->ops[type]->read_file_info(sb, type); 2363 if (error < 0) 2364 goto out_file_init; 2365 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2366 spin_lock(&dq_data_lock); 2367 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2368 spin_unlock(&dq_data_lock); 2369 } 2370 spin_lock(&dq_state_lock); 2371 dqopt->flags |= dquot_state_flag(flags, type); 2372 spin_unlock(&dq_state_lock); 2373 2374 add_dquot_ref(sb, type); 2375 2376 return 0; 2377 2378 out_file_init: 2379 dqopt->files[type] = NULL; 2380 iput(inode); 2381 out_file_flags: 2382 inode_lock(inode); 2383 inode->i_flags &= ~S_NOQUOTA; 2384 inode_unlock(inode); 2385 out_fmt: 2386 put_quota_format(fmt); 2387 2388 return error; 2389 } 2390 2391 /* Reenable quotas on remount RW */ 2392 int dquot_resume(struct super_block *sb, int type) 2393 { 2394 struct quota_info *dqopt = sb_dqopt(sb); 2395 struct inode *inode; 2396 int ret = 0, cnt; 2397 unsigned int flags; 2398 2399 /* s_umount should be held in exclusive mode */ 2400 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2401 up_read(&sb->s_umount); 2402 2403 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2404 if (type != -1 && cnt != type) 2405 continue; 2406 if (!sb_has_quota_suspended(sb, cnt)) 2407 continue; 2408 2409 inode = dqopt->files[cnt]; 2410 dqopt->files[cnt] = NULL; 2411 spin_lock(&dq_state_lock); 2412 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2413 DQUOT_LIMITS_ENABLED, 2414 cnt); 2415 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2416 spin_unlock(&dq_state_lock); 2417 2418 flags = dquot_generic_flag(flags, cnt); 2419 ret = vfs_load_quota_inode(inode, cnt, 2420 dqopt->info[cnt].dqi_fmt_id, flags); 2421 iput(inode); 2422 } 2423 2424 return ret; 2425 } 2426 EXPORT_SYMBOL(dquot_resume); 2427 2428 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2429 const struct path *path) 2430 { 2431 int error = security_quota_on(path->dentry); 2432 if (error) 2433 return error; 2434 /* Quota file not on the same filesystem? */ 2435 if (path->dentry->d_sb != sb) 2436 error = -EXDEV; 2437 else 2438 error = vfs_load_quota_inode(d_inode(path->dentry), type, 2439 format_id, DQUOT_USAGE_ENABLED | 2440 DQUOT_LIMITS_ENABLED); 2441 return error; 2442 } 2443 EXPORT_SYMBOL(dquot_quota_on); 2444 2445 /* 2446 * More powerful function for turning on quotas allowing setting 2447 * of individual quota flags 2448 */ 2449 int dquot_enable(struct inode *inode, int type, int format_id, 2450 unsigned int flags) 2451 { 2452 struct super_block *sb = inode->i_sb; 2453 2454 /* Just unsuspend quotas? */ 2455 BUG_ON(flags & DQUOT_SUSPENDED); 2456 /* s_umount should be held in exclusive mode */ 2457 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2458 up_read(&sb->s_umount); 2459 2460 if (!flags) 2461 return 0; 2462 /* Just updating flags needed? */ 2463 if (sb_has_quota_loaded(sb, type)) { 2464 if (flags & DQUOT_USAGE_ENABLED && 2465 sb_has_quota_usage_enabled(sb, type)) 2466 return -EBUSY; 2467 if (flags & DQUOT_LIMITS_ENABLED && 2468 sb_has_quota_limits_enabled(sb, type)) 2469 return -EBUSY; 2470 spin_lock(&dq_state_lock); 2471 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2472 spin_unlock(&dq_state_lock); 2473 return 0; 2474 } 2475 2476 return vfs_load_quota_inode(inode, type, format_id, flags); 2477 } 2478 EXPORT_SYMBOL(dquot_enable); 2479 2480 /* 2481 * This function is used when filesystem needs to initialize quotas 2482 * during mount time. 2483 */ 2484 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2485 int format_id, int type) 2486 { 2487 struct dentry *dentry; 2488 int error; 2489 2490 dentry = lookup_one_len_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2491 if (IS_ERR(dentry)) 2492 return PTR_ERR(dentry); 2493 2494 if (d_really_is_negative(dentry)) { 2495 error = -ENOENT; 2496 goto out; 2497 } 2498 2499 error = security_quota_on(dentry); 2500 if (!error) 2501 error = vfs_load_quota_inode(d_inode(dentry), type, format_id, 2502 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2503 2504 out: 2505 dput(dentry); 2506 return error; 2507 } 2508 EXPORT_SYMBOL(dquot_quota_on_mount); 2509 2510 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2511 { 2512 int ret; 2513 int type; 2514 struct quota_info *dqopt = sb_dqopt(sb); 2515 2516 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2517 return -ENOSYS; 2518 /* Accounting cannot be turned on while fs is mounted */ 2519 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2520 if (!flags) 2521 return -EINVAL; 2522 for (type = 0; type < MAXQUOTAS; type++) { 2523 if (!(flags & qtype_enforce_flag(type))) 2524 continue; 2525 /* Can't enforce without accounting */ 2526 if (!sb_has_quota_usage_enabled(sb, type)) 2527 return -EINVAL; 2528 ret = dquot_enable(dqopt->files[type], type, 2529 dqopt->info[type].dqi_fmt_id, 2530 DQUOT_LIMITS_ENABLED); 2531 if (ret < 0) 2532 goto out_err; 2533 } 2534 return 0; 2535 out_err: 2536 /* Backout enforcement enablement we already did */ 2537 for (type--; type >= 0; type--) { 2538 if (flags & qtype_enforce_flag(type)) 2539 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2540 } 2541 /* Error code translation for better compatibility with XFS */ 2542 if (ret == -EBUSY) 2543 ret = -EEXIST; 2544 return ret; 2545 } 2546 2547 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2548 { 2549 int ret; 2550 int type; 2551 struct quota_info *dqopt = sb_dqopt(sb); 2552 2553 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2554 return -ENOSYS; 2555 /* 2556 * We don't support turning off accounting via quotactl. In principle 2557 * quota infrastructure can do this but filesystems don't expect 2558 * userspace to be able to do it. 2559 */ 2560 if (flags & 2561 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2562 return -EOPNOTSUPP; 2563 2564 /* Filter out limits not enabled */ 2565 for (type = 0; type < MAXQUOTAS; type++) 2566 if (!sb_has_quota_limits_enabled(sb, type)) 2567 flags &= ~qtype_enforce_flag(type); 2568 /* Nothing left? */ 2569 if (!flags) 2570 return -EEXIST; 2571 for (type = 0; type < MAXQUOTAS; type++) { 2572 if (flags & qtype_enforce_flag(type)) { 2573 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2574 if (ret < 0) 2575 goto out_err; 2576 } 2577 } 2578 return 0; 2579 out_err: 2580 /* Backout enforcement disabling we already did */ 2581 for (type--; type >= 0; type--) { 2582 if (flags & qtype_enforce_flag(type)) 2583 dquot_enable(dqopt->files[type], type, 2584 dqopt->info[type].dqi_fmt_id, 2585 DQUOT_LIMITS_ENABLED); 2586 } 2587 return ret; 2588 } 2589 2590 /* Generic routine for getting common part of quota structure */ 2591 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2592 { 2593 struct mem_dqblk *dm = &dquot->dq_dqb; 2594 2595 memset(di, 0, sizeof(*di)); 2596 spin_lock(&dquot->dq_dqb_lock); 2597 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2598 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2599 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2600 di->d_ino_softlimit = dm->dqb_isoftlimit; 2601 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2602 di->d_ino_count = dm->dqb_curinodes; 2603 di->d_spc_timer = dm->dqb_btime; 2604 di->d_ino_timer = dm->dqb_itime; 2605 spin_unlock(&dquot->dq_dqb_lock); 2606 } 2607 2608 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2609 struct qc_dqblk *di) 2610 { 2611 struct dquot *dquot; 2612 2613 dquot = dqget(sb, qid); 2614 if (IS_ERR(dquot)) 2615 return PTR_ERR(dquot); 2616 do_get_dqblk(dquot, di); 2617 dqput(dquot); 2618 2619 return 0; 2620 } 2621 EXPORT_SYMBOL(dquot_get_dqblk); 2622 2623 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2624 struct qc_dqblk *di) 2625 { 2626 struct dquot *dquot; 2627 int err; 2628 2629 if (!sb->dq_op->get_next_id) 2630 return -ENOSYS; 2631 err = sb->dq_op->get_next_id(sb, qid); 2632 if (err < 0) 2633 return err; 2634 dquot = dqget(sb, *qid); 2635 if (IS_ERR(dquot)) 2636 return PTR_ERR(dquot); 2637 do_get_dqblk(dquot, di); 2638 dqput(dquot); 2639 2640 return 0; 2641 } 2642 EXPORT_SYMBOL(dquot_get_next_dqblk); 2643 2644 #define VFS_QC_MASK \ 2645 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2646 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2647 QC_SPC_TIMER | QC_INO_TIMER) 2648 2649 /* Generic routine for setting common part of quota structure */ 2650 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2651 { 2652 struct mem_dqblk *dm = &dquot->dq_dqb; 2653 int check_blim = 0, check_ilim = 0; 2654 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2655 2656 if (di->d_fieldmask & ~VFS_QC_MASK) 2657 return -EINVAL; 2658 2659 if (((di->d_fieldmask & QC_SPC_SOFT) && 2660 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2661 ((di->d_fieldmask & QC_SPC_HARD) && 2662 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2663 ((di->d_fieldmask & QC_INO_SOFT) && 2664 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2665 ((di->d_fieldmask & QC_INO_HARD) && 2666 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2667 return -ERANGE; 2668 2669 spin_lock(&dquot->dq_dqb_lock); 2670 if (di->d_fieldmask & QC_SPACE) { 2671 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2672 check_blim = 1; 2673 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2674 } 2675 2676 if (di->d_fieldmask & QC_SPC_SOFT) 2677 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2678 if (di->d_fieldmask & QC_SPC_HARD) 2679 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2680 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2681 check_blim = 1; 2682 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2683 } 2684 2685 if (di->d_fieldmask & QC_INO_COUNT) { 2686 dm->dqb_curinodes = di->d_ino_count; 2687 check_ilim = 1; 2688 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2689 } 2690 2691 if (di->d_fieldmask & QC_INO_SOFT) 2692 dm->dqb_isoftlimit = di->d_ino_softlimit; 2693 if (di->d_fieldmask & QC_INO_HARD) 2694 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2695 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2696 check_ilim = 1; 2697 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2698 } 2699 2700 if (di->d_fieldmask & QC_SPC_TIMER) { 2701 dm->dqb_btime = di->d_spc_timer; 2702 check_blim = 1; 2703 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2704 } 2705 2706 if (di->d_fieldmask & QC_INO_TIMER) { 2707 dm->dqb_itime = di->d_ino_timer; 2708 check_ilim = 1; 2709 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2710 } 2711 2712 if (check_blim) { 2713 if (!dm->dqb_bsoftlimit || 2714 dm->dqb_curspace + dm->dqb_rsvspace < dm->dqb_bsoftlimit) { 2715 dm->dqb_btime = 0; 2716 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2717 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2718 /* Set grace only if user hasn't provided his own... */ 2719 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2720 } 2721 if (check_ilim) { 2722 if (!dm->dqb_isoftlimit || 2723 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2724 dm->dqb_itime = 0; 2725 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2726 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2727 /* Set grace only if user hasn't provided his own... */ 2728 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2729 } 2730 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2731 dm->dqb_isoftlimit) 2732 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2733 else 2734 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2735 spin_unlock(&dquot->dq_dqb_lock); 2736 mark_dquot_dirty(dquot); 2737 2738 return 0; 2739 } 2740 2741 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2742 struct qc_dqblk *di) 2743 { 2744 struct dquot *dquot; 2745 int rc; 2746 2747 dquot = dqget(sb, qid); 2748 if (IS_ERR(dquot)) { 2749 rc = PTR_ERR(dquot); 2750 goto out; 2751 } 2752 rc = do_set_dqblk(dquot, di); 2753 dqput(dquot); 2754 out: 2755 return rc; 2756 } 2757 EXPORT_SYMBOL(dquot_set_dqblk); 2758 2759 /* Generic routine for getting common part of quota file information */ 2760 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2761 { 2762 struct mem_dqinfo *mi; 2763 struct qc_type_state *tstate; 2764 struct quota_info *dqopt = sb_dqopt(sb); 2765 int type; 2766 2767 memset(state, 0, sizeof(*state)); 2768 for (type = 0; type < MAXQUOTAS; type++) { 2769 if (!sb_has_quota_active(sb, type)) 2770 continue; 2771 tstate = state->s_state + type; 2772 mi = sb_dqopt(sb)->info + type; 2773 tstate->flags = QCI_ACCT_ENABLED; 2774 spin_lock(&dq_data_lock); 2775 if (mi->dqi_flags & DQF_SYS_FILE) 2776 tstate->flags |= QCI_SYSFILE; 2777 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2778 tstate->flags |= QCI_ROOT_SQUASH; 2779 if (sb_has_quota_limits_enabled(sb, type)) 2780 tstate->flags |= QCI_LIMITS_ENFORCED; 2781 tstate->spc_timelimit = mi->dqi_bgrace; 2782 tstate->ino_timelimit = mi->dqi_igrace; 2783 tstate->ino = dqopt->files[type]->i_ino; 2784 tstate->blocks = dqopt->files[type]->i_blocks; 2785 tstate->nextents = 1; /* We don't know... */ 2786 spin_unlock(&dq_data_lock); 2787 } 2788 return 0; 2789 } 2790 EXPORT_SYMBOL(dquot_get_state); 2791 2792 /* Generic routine for setting common part of quota file information */ 2793 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2794 { 2795 struct mem_dqinfo *mi; 2796 int err = 0; 2797 2798 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2799 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2800 return -EINVAL; 2801 if (!sb_has_quota_active(sb, type)) 2802 return -ESRCH; 2803 mi = sb_dqopt(sb)->info + type; 2804 if (ii->i_fieldmask & QC_FLAGS) { 2805 if ((ii->i_flags & QCI_ROOT_SQUASH && 2806 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2807 return -EINVAL; 2808 } 2809 spin_lock(&dq_data_lock); 2810 if (ii->i_fieldmask & QC_SPC_TIMER) 2811 mi->dqi_bgrace = ii->i_spc_timelimit; 2812 if (ii->i_fieldmask & QC_INO_TIMER) 2813 mi->dqi_igrace = ii->i_ino_timelimit; 2814 if (ii->i_fieldmask & QC_FLAGS) { 2815 if (ii->i_flags & QCI_ROOT_SQUASH) 2816 mi->dqi_flags |= DQF_ROOT_SQUASH; 2817 else 2818 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2819 } 2820 spin_unlock(&dq_data_lock); 2821 mark_info_dirty(sb, type); 2822 /* Force write to disk */ 2823 sb->dq_op->write_info(sb, type); 2824 return err; 2825 } 2826 EXPORT_SYMBOL(dquot_set_dqinfo); 2827 2828 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2829 .quota_enable = dquot_quota_enable, 2830 .quota_disable = dquot_quota_disable, 2831 .quota_sync = dquot_quota_sync, 2832 .get_state = dquot_get_state, 2833 .set_info = dquot_set_dqinfo, 2834 .get_dqblk = dquot_get_dqblk, 2835 .get_nextdqblk = dquot_get_next_dqblk, 2836 .set_dqblk = dquot_set_dqblk 2837 }; 2838 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2839 2840 static int do_proc_dqstats(struct ctl_table *table, int write, 2841 void __user *buffer, size_t *lenp, loff_t *ppos) 2842 { 2843 unsigned int type = (int *)table->data - dqstats.stat; 2844 2845 /* Update global table */ 2846 dqstats.stat[type] = 2847 percpu_counter_sum_positive(&dqstats.counter[type]); 2848 return proc_dointvec(table, write, buffer, lenp, ppos); 2849 } 2850 2851 static struct ctl_table fs_dqstats_table[] = { 2852 { 2853 .procname = "lookups", 2854 .data = &dqstats.stat[DQST_LOOKUPS], 2855 .maxlen = sizeof(int), 2856 .mode = 0444, 2857 .proc_handler = do_proc_dqstats, 2858 }, 2859 { 2860 .procname = "drops", 2861 .data = &dqstats.stat[DQST_DROPS], 2862 .maxlen = sizeof(int), 2863 .mode = 0444, 2864 .proc_handler = do_proc_dqstats, 2865 }, 2866 { 2867 .procname = "reads", 2868 .data = &dqstats.stat[DQST_READS], 2869 .maxlen = sizeof(int), 2870 .mode = 0444, 2871 .proc_handler = do_proc_dqstats, 2872 }, 2873 { 2874 .procname = "writes", 2875 .data = &dqstats.stat[DQST_WRITES], 2876 .maxlen = sizeof(int), 2877 .mode = 0444, 2878 .proc_handler = do_proc_dqstats, 2879 }, 2880 { 2881 .procname = "cache_hits", 2882 .data = &dqstats.stat[DQST_CACHE_HITS], 2883 .maxlen = sizeof(int), 2884 .mode = 0444, 2885 .proc_handler = do_proc_dqstats, 2886 }, 2887 { 2888 .procname = "allocated_dquots", 2889 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2890 .maxlen = sizeof(int), 2891 .mode = 0444, 2892 .proc_handler = do_proc_dqstats, 2893 }, 2894 { 2895 .procname = "free_dquots", 2896 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2897 .maxlen = sizeof(int), 2898 .mode = 0444, 2899 .proc_handler = do_proc_dqstats, 2900 }, 2901 { 2902 .procname = "syncs", 2903 .data = &dqstats.stat[DQST_SYNCS], 2904 .maxlen = sizeof(int), 2905 .mode = 0444, 2906 .proc_handler = do_proc_dqstats, 2907 }, 2908 #ifdef CONFIG_PRINT_QUOTA_WARNING 2909 { 2910 .procname = "warnings", 2911 .data = &flag_print_warnings, 2912 .maxlen = sizeof(int), 2913 .mode = 0644, 2914 .proc_handler = proc_dointvec, 2915 }, 2916 #endif 2917 { }, 2918 }; 2919 2920 static struct ctl_table fs_table[] = { 2921 { 2922 .procname = "quota", 2923 .mode = 0555, 2924 .child = fs_dqstats_table, 2925 }, 2926 { }, 2927 }; 2928 2929 static struct ctl_table sys_table[] = { 2930 { 2931 .procname = "fs", 2932 .mode = 0555, 2933 .child = fs_table, 2934 }, 2935 { }, 2936 }; 2937 2938 static int __init dquot_init(void) 2939 { 2940 int i, ret; 2941 unsigned long nr_hash, order; 2942 2943 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2944 2945 register_sysctl_table(sys_table); 2946 2947 dquot_cachep = kmem_cache_create("dquot", 2948 sizeof(struct dquot), sizeof(unsigned long) * 4, 2949 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2950 SLAB_MEM_SPREAD|SLAB_PANIC), 2951 NULL); 2952 2953 order = 0; 2954 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2955 if (!dquot_hash) 2956 panic("Cannot create dquot hash table"); 2957 2958 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2959 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2960 if (ret) 2961 panic("Cannot create dquot stat counters"); 2962 } 2963 2964 /* Find power-of-two hlist_heads which can fit into allocation */ 2965 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2966 dq_hash_bits = 0; 2967 do { 2968 dq_hash_bits++; 2969 } while (nr_hash >> dq_hash_bits); 2970 dq_hash_bits--; 2971 2972 nr_hash = 1UL << dq_hash_bits; 2973 dq_hash_mask = nr_hash - 1; 2974 for (i = 0; i < nr_hash; i++) 2975 INIT_HLIST_HEAD(dquot_hash + i); 2976 2977 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2978 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2979 2980 register_shrinker(&dqcache_shrinker); 2981 2982 return 0; 2983 } 2984 fs_initcall(dquot_init); 2985