1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implementation of the diskquota system for the LINUX operating system. QUOTA 4 * is implemented using the BSD system call interface as the means of 5 * communication with the user level. This file contains the generic routines 6 * called by the different filesystems on allocation of an inode or block. 7 * These routines take care of the administration needed to have a consistent 8 * diskquota tracking system. The ideas of both user and group quotas are based 9 * on the Melbourne quota system as used on BSD derived systems. The internal 10 * implementation is based on one of the several variants of the LINUX 11 * inode-subsystem with added complexity of the diskquota system. 12 * 13 * Author: Marco van Wieringen <mvw@planets.elm.net> 14 * 15 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 16 * 17 * Revised list management to avoid races 18 * -- Bill Hawes, <whawes@star.net>, 9/98 19 * 20 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). 21 * As the consequence the locking was moved from dquot_decr_...(), 22 * dquot_incr_...() to calling functions. 23 * invalidate_dquots() now writes modified dquots. 24 * Serialized quota_off() and quota_on() for mount point. 25 * Fixed a few bugs in grow_dquots(). 26 * Fixed deadlock in write_dquot() - we no longer account quotas on 27 * quota files 28 * remove_dquot_ref() moved to inode.c - it now traverses through inodes 29 * add_dquot_ref() restarts after blocking 30 * Added check for bogus uid and fixed check for group in quotactl. 31 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99 32 * 33 * Used struct list_head instead of own list struct 34 * Invalidation of referenced dquots is no longer possible 35 * Improved free_dquots list management 36 * Quota and i_blocks are now updated in one place to avoid races 37 * Warnings are now delayed so we won't block in critical section 38 * Write updated not to require dquot lock 39 * Jan Kara, <jack@suse.cz>, 9/2000 40 * 41 * Added dynamic quota structure allocation 42 * Jan Kara <jack@suse.cz> 12/2000 43 * 44 * Rewritten quota interface. Implemented new quota format and 45 * formats registering. 46 * Jan Kara, <jack@suse.cz>, 2001,2002 47 * 48 * New SMP locking. 49 * Jan Kara, <jack@suse.cz>, 10/2002 50 * 51 * Added journalled quota support, fix lock inversion problems 52 * Jan Kara, <jack@suse.cz>, 2003,2004 53 * 54 * (C) Copyright 1994 - 1997 Marco van Wieringen 55 */ 56 57 #include <linux/errno.h> 58 #include <linux/kernel.h> 59 #include <linux/fs.h> 60 #include <linux/mount.h> 61 #include <linux/mm.h> 62 #include <linux/time.h> 63 #include <linux/types.h> 64 #include <linux/string.h> 65 #include <linux/fcntl.h> 66 #include <linux/stat.h> 67 #include <linux/tty.h> 68 #include <linux/file.h> 69 #include <linux/slab.h> 70 #include <linux/sysctl.h> 71 #include <linux/init.h> 72 #include <linux/module.h> 73 #include <linux/proc_fs.h> 74 #include <linux/security.h> 75 #include <linux/sched.h> 76 #include <linux/cred.h> 77 #include <linux/kmod.h> 78 #include <linux/namei.h> 79 #include <linux/capability.h> 80 #include <linux/quotaops.h> 81 #include <linux/blkdev.h> 82 #include <linux/sched/mm.h> 83 #include "../internal.h" /* ugh */ 84 85 #include <linux/uaccess.h> 86 87 /* 88 * There are five quota SMP locks: 89 * * dq_list_lock protects all lists with quotas and quota formats. 90 * * dquot->dq_dqb_lock protects data from dq_dqb 91 * * inode->i_lock protects inode->i_blocks, i_bytes and also guards 92 * consistency of dquot->dq_dqb with inode->i_blocks, i_bytes so that 93 * dquot_transfer() can stabilize amount it transfers 94 * * dq_data_lock protects mem_dqinfo structures and modifications of dquot 95 * pointers in the inode 96 * * dq_state_lock protects modifications of quota state (on quotaon and 97 * quotaoff) and readers who care about latest values take it as well. 98 * 99 * The spinlock ordering is hence: 100 * dq_data_lock > dq_list_lock > i_lock > dquot->dq_dqb_lock, 101 * dq_list_lock > dq_state_lock 102 * 103 * Note that some things (eg. sb pointer, type, id) doesn't change during 104 * the life of the dquot structure and so needn't to be protected by a lock 105 * 106 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 107 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 108 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 109 * inode and before dropping dquot references to avoid use of dquots after 110 * they are freed. dq_data_lock is used to serialize the pointer setting and 111 * clearing operations. 112 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 113 * inode is a quota file). Functions adding pointers from inode to dquots have 114 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 115 * have to do all pointer modifications before dropping dq_data_lock. This makes 116 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 117 * then drops all pointers to dquots from an inode. 118 * 119 * Each dquot has its dq_lock mutex. Dquot is locked when it is being read to 120 * memory (or space for it is being allocated) on the first dqget(), when it is 121 * being written out, and when it is being released on the last dqput(). The 122 * allocation and release operations are serialized by the dq_lock and by 123 * checking the use count in dquot_release(). 124 * 125 * Lock ordering (including related VFS locks) is the following: 126 * s_umount > i_mutex > journal_lock > dquot->dq_lock > dqio_sem 127 */ 128 129 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 131 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 132 EXPORT_SYMBOL(dq_data_lock); 133 DEFINE_STATIC_SRCU(dquot_srcu); 134 135 static DECLARE_WAIT_QUEUE_HEAD(dquot_ref_wq); 136 137 void __quota_error(struct super_block *sb, const char *func, 138 const char *fmt, ...) 139 { 140 if (printk_ratelimit()) { 141 va_list args; 142 struct va_format vaf; 143 144 va_start(args, fmt); 145 146 vaf.fmt = fmt; 147 vaf.va = &args; 148 149 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 150 sb->s_id, func, &vaf); 151 152 va_end(args); 153 } 154 } 155 EXPORT_SYMBOL(__quota_error); 156 157 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 158 static char *quotatypes[] = INITQFNAMES; 159 #endif 160 static struct quota_format_type *quota_formats; /* List of registered formats */ 161 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 162 163 /* SLAB cache for dquot structures */ 164 static struct kmem_cache *dquot_cachep; 165 166 int register_quota_format(struct quota_format_type *fmt) 167 { 168 spin_lock(&dq_list_lock); 169 fmt->qf_next = quota_formats; 170 quota_formats = fmt; 171 spin_unlock(&dq_list_lock); 172 return 0; 173 } 174 EXPORT_SYMBOL(register_quota_format); 175 176 void unregister_quota_format(struct quota_format_type *fmt) 177 { 178 struct quota_format_type **actqf; 179 180 spin_lock(&dq_list_lock); 181 for (actqf = "a_formats; *actqf && *actqf != fmt; 182 actqf = &(*actqf)->qf_next) 183 ; 184 if (*actqf) 185 *actqf = (*actqf)->qf_next; 186 spin_unlock(&dq_list_lock); 187 } 188 EXPORT_SYMBOL(unregister_quota_format); 189 190 static struct quota_format_type *find_quota_format(int id) 191 { 192 struct quota_format_type *actqf; 193 194 spin_lock(&dq_list_lock); 195 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 196 actqf = actqf->qf_next) 197 ; 198 if (!actqf || !try_module_get(actqf->qf_owner)) { 199 int qm; 200 201 spin_unlock(&dq_list_lock); 202 203 for (qm = 0; module_names[qm].qm_fmt_id && 204 module_names[qm].qm_fmt_id != id; qm++) 205 ; 206 if (!module_names[qm].qm_fmt_id || 207 request_module(module_names[qm].qm_mod_name)) 208 return NULL; 209 210 spin_lock(&dq_list_lock); 211 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 212 actqf = actqf->qf_next) 213 ; 214 if (actqf && !try_module_get(actqf->qf_owner)) 215 actqf = NULL; 216 } 217 spin_unlock(&dq_list_lock); 218 return actqf; 219 } 220 221 static void put_quota_format(struct quota_format_type *fmt) 222 { 223 module_put(fmt->qf_owner); 224 } 225 226 /* 227 * Dquot List Management: 228 * The quota code uses four lists for dquot management: the inuse_list, 229 * free_dquots, dqi_dirty_list, and dquot_hash[] array. A single dquot 230 * structure may be on some of those lists, depending on its current state. 231 * 232 * All dquots are placed to the end of inuse_list when first created, and this 233 * list is used for invalidate operation, which must look at every dquot. 234 * 235 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 236 * and this list is searched whenever we need an available dquot. Dquots are 237 * removed from the list as soon as they are used again, and 238 * dqstats.free_dquots gives the number of dquots on the list. When 239 * dquot is invalidated it's completely released from memory. 240 * 241 * Dirty dquots are added to the dqi_dirty_list of quota_info when mark 242 * dirtied, and this list is searched when writing dirty dquots back to 243 * quota file. Note that some filesystems do dirty dquot tracking on their 244 * own (e.g. in a journal) and thus don't use dqi_dirty_list. 245 * 246 * Dquots with a specific identity (device, type and id) are placed on 247 * one of the dquot_hash[] hash chains. The provides an efficient search 248 * mechanism to locate a specific dquot. 249 */ 250 251 static LIST_HEAD(inuse_list); 252 static LIST_HEAD(free_dquots); 253 static unsigned int dq_hash_bits, dq_hash_mask; 254 static struct hlist_head *dquot_hash; 255 256 struct dqstats dqstats; 257 EXPORT_SYMBOL(dqstats); 258 259 static qsize_t inode_get_rsv_space(struct inode *inode); 260 static qsize_t __inode_get_rsv_space(struct inode *inode); 261 static int __dquot_initialize(struct inode *inode, int type); 262 263 static inline unsigned int 264 hashfn(const struct super_block *sb, struct kqid qid) 265 { 266 unsigned int id = from_kqid(&init_user_ns, qid); 267 int type = qid.type; 268 unsigned long tmp; 269 270 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 271 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 272 } 273 274 /* 275 * Following list functions expect dq_list_lock to be held 276 */ 277 static inline void insert_dquot_hash(struct dquot *dquot) 278 { 279 struct hlist_head *head; 280 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 281 hlist_add_head(&dquot->dq_hash, head); 282 } 283 284 static inline void remove_dquot_hash(struct dquot *dquot) 285 { 286 hlist_del_init(&dquot->dq_hash); 287 } 288 289 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 290 struct kqid qid) 291 { 292 struct dquot *dquot; 293 294 hlist_for_each_entry(dquot, dquot_hash+hashent, dq_hash) 295 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 296 return dquot; 297 298 return NULL; 299 } 300 301 /* Add a dquot to the tail of the free list */ 302 static inline void put_dquot_last(struct dquot *dquot) 303 { 304 list_add_tail(&dquot->dq_free, &free_dquots); 305 dqstats_inc(DQST_FREE_DQUOTS); 306 } 307 308 static inline void remove_free_dquot(struct dquot *dquot) 309 { 310 if (list_empty(&dquot->dq_free)) 311 return; 312 list_del_init(&dquot->dq_free); 313 dqstats_dec(DQST_FREE_DQUOTS); 314 } 315 316 static inline void put_inuse(struct dquot *dquot) 317 { 318 /* We add to the back of inuse list so we don't have to restart 319 * when traversing this list and we block */ 320 list_add_tail(&dquot->dq_inuse, &inuse_list); 321 dqstats_inc(DQST_ALLOC_DQUOTS); 322 } 323 324 static inline void remove_inuse(struct dquot *dquot) 325 { 326 dqstats_dec(DQST_ALLOC_DQUOTS); 327 list_del(&dquot->dq_inuse); 328 } 329 /* 330 * End of list functions needing dq_list_lock 331 */ 332 333 static void wait_on_dquot(struct dquot *dquot) 334 { 335 mutex_lock(&dquot->dq_lock); 336 mutex_unlock(&dquot->dq_lock); 337 } 338 339 static inline int dquot_dirty(struct dquot *dquot) 340 { 341 return test_bit(DQ_MOD_B, &dquot->dq_flags); 342 } 343 344 static inline int mark_dquot_dirty(struct dquot *dquot) 345 { 346 return dquot->dq_sb->dq_op->mark_dirty(dquot); 347 } 348 349 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 350 int dquot_mark_dquot_dirty(struct dquot *dquot) 351 { 352 int ret = 1; 353 354 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 355 return 0; 356 357 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 358 return test_and_set_bit(DQ_MOD_B, &dquot->dq_flags); 359 360 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 361 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 362 return 1; 363 364 spin_lock(&dq_list_lock); 365 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 366 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 367 info[dquot->dq_id.type].dqi_dirty_list); 368 ret = 0; 369 } 370 spin_unlock(&dq_list_lock); 371 return ret; 372 } 373 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 374 375 /* Dirtify all the dquots - this can block when journalling */ 376 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 377 { 378 int ret, err, cnt; 379 380 ret = err = 0; 381 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 382 if (dquot[cnt]) 383 /* Even in case of error we have to continue */ 384 ret = mark_dquot_dirty(dquot[cnt]); 385 if (!err) 386 err = ret; 387 } 388 return err; 389 } 390 391 static inline void dqput_all(struct dquot **dquot) 392 { 393 unsigned int cnt; 394 395 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 396 dqput(dquot[cnt]); 397 } 398 399 static inline int clear_dquot_dirty(struct dquot *dquot) 400 { 401 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NOLIST_DIRTY) 402 return test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags); 403 404 spin_lock(&dq_list_lock); 405 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) { 406 spin_unlock(&dq_list_lock); 407 return 0; 408 } 409 list_del_init(&dquot->dq_dirty); 410 spin_unlock(&dq_list_lock); 411 return 1; 412 } 413 414 void mark_info_dirty(struct super_block *sb, int type) 415 { 416 spin_lock(&dq_data_lock); 417 sb_dqopt(sb)->info[type].dqi_flags |= DQF_INFO_DIRTY; 418 spin_unlock(&dq_data_lock); 419 } 420 EXPORT_SYMBOL(mark_info_dirty); 421 422 /* 423 * Read dquot from disk and alloc space for it 424 */ 425 426 int dquot_acquire(struct dquot *dquot) 427 { 428 int ret = 0, ret2 = 0; 429 unsigned int memalloc; 430 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 431 432 mutex_lock(&dquot->dq_lock); 433 memalloc = memalloc_nofs_save(); 434 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) { 435 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 436 if (ret < 0) 437 goto out_iolock; 438 } 439 /* Make sure flags update is visible after dquot has been filled */ 440 smp_mb__before_atomic(); 441 set_bit(DQ_READ_B, &dquot->dq_flags); 442 /* Instantiate dquot if needed */ 443 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 444 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 445 /* Write the info if needed */ 446 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 447 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 448 dquot->dq_sb, dquot->dq_id.type); 449 } 450 if (ret < 0) 451 goto out_iolock; 452 if (ret2 < 0) { 453 ret = ret2; 454 goto out_iolock; 455 } 456 } 457 /* 458 * Make sure flags update is visible after on-disk struct has been 459 * allocated. Paired with smp_rmb() in dqget(). 460 */ 461 smp_mb__before_atomic(); 462 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 463 out_iolock: 464 memalloc_nofs_restore(memalloc); 465 mutex_unlock(&dquot->dq_lock); 466 return ret; 467 } 468 EXPORT_SYMBOL(dquot_acquire); 469 470 /* 471 * Write dquot to disk 472 */ 473 int dquot_commit(struct dquot *dquot) 474 { 475 int ret = 0; 476 unsigned int memalloc; 477 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 478 479 mutex_lock(&dquot->dq_lock); 480 memalloc = memalloc_nofs_save(); 481 if (!clear_dquot_dirty(dquot)) 482 goto out_lock; 483 /* Inactive dquot can be only if there was error during read/init 484 * => we have better not writing it */ 485 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 486 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 487 else 488 ret = -EIO; 489 out_lock: 490 memalloc_nofs_restore(memalloc); 491 mutex_unlock(&dquot->dq_lock); 492 return ret; 493 } 494 EXPORT_SYMBOL(dquot_commit); 495 496 /* 497 * Release dquot 498 */ 499 int dquot_release(struct dquot *dquot) 500 { 501 int ret = 0, ret2 = 0; 502 unsigned int memalloc; 503 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 504 505 mutex_lock(&dquot->dq_lock); 506 memalloc = memalloc_nofs_save(); 507 /* Check whether we are not racing with some other dqget() */ 508 if (dquot_is_busy(dquot)) 509 goto out_dqlock; 510 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 511 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 512 /* Write the info */ 513 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 514 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 515 dquot->dq_sb, dquot->dq_id.type); 516 } 517 if (ret >= 0) 518 ret = ret2; 519 } 520 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 521 out_dqlock: 522 memalloc_nofs_restore(memalloc); 523 mutex_unlock(&dquot->dq_lock); 524 return ret; 525 } 526 EXPORT_SYMBOL(dquot_release); 527 528 void dquot_destroy(struct dquot *dquot) 529 { 530 kmem_cache_free(dquot_cachep, dquot); 531 } 532 EXPORT_SYMBOL(dquot_destroy); 533 534 static inline void do_destroy_dquot(struct dquot *dquot) 535 { 536 dquot->dq_sb->dq_op->destroy_dquot(dquot); 537 } 538 539 /* Invalidate all dquots on the list. Note that this function is called after 540 * quota is disabled and pointers from inodes removed so there cannot be new 541 * quota users. There can still be some users of quotas due to inodes being 542 * just deleted or pruned by prune_icache() (those are not attached to any 543 * list) or parallel quotactl call. We have to wait for such users. 544 */ 545 static void invalidate_dquots(struct super_block *sb, int type) 546 { 547 struct dquot *dquot, *tmp; 548 549 restart: 550 spin_lock(&dq_list_lock); 551 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 552 if (dquot->dq_sb != sb) 553 continue; 554 if (dquot->dq_id.type != type) 555 continue; 556 /* Wait for dquot users */ 557 if (atomic_read(&dquot->dq_count)) { 558 dqgrab(dquot); 559 spin_unlock(&dq_list_lock); 560 /* 561 * Once dqput() wakes us up, we know it's time to free 562 * the dquot. 563 * IMPORTANT: we rely on the fact that there is always 564 * at most one process waiting for dquot to free. 565 * Otherwise dq_count would be > 1 and we would never 566 * wake up. 567 */ 568 wait_event(dquot_ref_wq, 569 atomic_read(&dquot->dq_count) == 1); 570 dqput(dquot); 571 /* At this moment dquot() need not exist (it could be 572 * reclaimed by prune_dqcache(). Hence we must 573 * restart. */ 574 goto restart; 575 } 576 /* 577 * Quota now has no users and it has been written on last 578 * dqput() 579 */ 580 remove_dquot_hash(dquot); 581 remove_free_dquot(dquot); 582 remove_inuse(dquot); 583 do_destroy_dquot(dquot); 584 } 585 spin_unlock(&dq_list_lock); 586 } 587 588 /* Call callback for every active dquot on given filesystem */ 589 int dquot_scan_active(struct super_block *sb, 590 int (*fn)(struct dquot *dquot, unsigned long priv), 591 unsigned long priv) 592 { 593 struct dquot *dquot, *old_dquot = NULL; 594 int ret = 0; 595 596 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 597 598 spin_lock(&dq_list_lock); 599 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 600 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 601 continue; 602 if (dquot->dq_sb != sb) 603 continue; 604 /* Now we have active dquot so we can just increase use count */ 605 atomic_inc(&dquot->dq_count); 606 spin_unlock(&dq_list_lock); 607 dqput(old_dquot); 608 old_dquot = dquot; 609 /* 610 * ->release_dquot() can be racing with us. Our reference 611 * protects us from new calls to it so just wait for any 612 * outstanding call and recheck the DQ_ACTIVE_B after that. 613 */ 614 wait_on_dquot(dquot); 615 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 616 ret = fn(dquot, priv); 617 if (ret < 0) 618 goto out; 619 } 620 spin_lock(&dq_list_lock); 621 /* We are safe to continue now because our dquot could not 622 * be moved out of the inuse list while we hold the reference */ 623 } 624 spin_unlock(&dq_list_lock); 625 out: 626 dqput(old_dquot); 627 return ret; 628 } 629 EXPORT_SYMBOL(dquot_scan_active); 630 631 /* Write all dquot structures to quota files */ 632 int dquot_writeback_dquots(struct super_block *sb, int type) 633 { 634 struct list_head dirty; 635 struct dquot *dquot; 636 struct quota_info *dqopt = sb_dqopt(sb); 637 int cnt; 638 int err, ret = 0; 639 640 WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); 641 642 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 643 if (type != -1 && cnt != type) 644 continue; 645 if (!sb_has_quota_active(sb, cnt)) 646 continue; 647 spin_lock(&dq_list_lock); 648 /* Move list away to avoid livelock. */ 649 list_replace_init(&dqopt->info[cnt].dqi_dirty_list, &dirty); 650 while (!list_empty(&dirty)) { 651 dquot = list_first_entry(&dirty, struct dquot, 652 dq_dirty); 653 654 WARN_ON(!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)); 655 656 /* Now we have active dquot from which someone is 657 * holding reference so we can safely just increase 658 * use count */ 659 dqgrab(dquot); 660 spin_unlock(&dq_list_lock); 661 err = sb->dq_op->write_dquot(dquot); 662 if (err) { 663 /* 664 * Clear dirty bit anyway to avoid infinite 665 * loop here. 666 */ 667 clear_dquot_dirty(dquot); 668 if (!ret) 669 ret = err; 670 } 671 dqput(dquot); 672 spin_lock(&dq_list_lock); 673 } 674 spin_unlock(&dq_list_lock); 675 } 676 677 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 678 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 679 && info_dirty(&dqopt->info[cnt])) 680 sb->dq_op->write_info(sb, cnt); 681 dqstats_inc(DQST_SYNCS); 682 683 return ret; 684 } 685 EXPORT_SYMBOL(dquot_writeback_dquots); 686 687 /* Write all dquot structures to disk and make them visible from userspace */ 688 int dquot_quota_sync(struct super_block *sb, int type) 689 { 690 struct quota_info *dqopt = sb_dqopt(sb); 691 int cnt; 692 int ret; 693 694 ret = dquot_writeback_dquots(sb, type); 695 if (ret) 696 return ret; 697 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 698 return 0; 699 700 /* This is not very clever (and fast) but currently I don't know about 701 * any other simple way of getting quota data to disk and we must get 702 * them there for userspace to be visible... */ 703 if (sb->s_op->sync_fs) { 704 ret = sb->s_op->sync_fs(sb, 1); 705 if (ret) 706 return ret; 707 } 708 ret = sync_blockdev(sb->s_bdev); 709 if (ret) 710 return ret; 711 712 /* 713 * Now when everything is written we can discard the pagecache so 714 * that userspace sees the changes. 715 */ 716 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 717 if (type != -1 && cnt != type) 718 continue; 719 if (!sb_has_quota_active(sb, cnt)) 720 continue; 721 inode_lock(dqopt->files[cnt]); 722 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 723 inode_unlock(dqopt->files[cnt]); 724 } 725 726 return 0; 727 } 728 EXPORT_SYMBOL(dquot_quota_sync); 729 730 static unsigned long 731 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 732 { 733 struct dquot *dquot; 734 unsigned long freed = 0; 735 736 spin_lock(&dq_list_lock); 737 while (!list_empty(&free_dquots) && sc->nr_to_scan) { 738 dquot = list_first_entry(&free_dquots, struct dquot, dq_free); 739 remove_dquot_hash(dquot); 740 remove_free_dquot(dquot); 741 remove_inuse(dquot); 742 do_destroy_dquot(dquot); 743 sc->nr_to_scan--; 744 freed++; 745 } 746 spin_unlock(&dq_list_lock); 747 return freed; 748 } 749 750 static unsigned long 751 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 752 { 753 return vfs_pressure_ratio( 754 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 755 } 756 757 static struct shrinker dqcache_shrinker = { 758 .count_objects = dqcache_shrink_count, 759 .scan_objects = dqcache_shrink_scan, 760 .seeks = DEFAULT_SEEKS, 761 }; 762 763 /* 764 * Put reference to dquot 765 */ 766 void dqput(struct dquot *dquot) 767 { 768 int ret; 769 770 if (!dquot) 771 return; 772 #ifdef CONFIG_QUOTA_DEBUG 773 if (!atomic_read(&dquot->dq_count)) { 774 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 775 quotatypes[dquot->dq_id.type], 776 from_kqid(&init_user_ns, dquot->dq_id)); 777 BUG(); 778 } 779 #endif 780 dqstats_inc(DQST_DROPS); 781 we_slept: 782 spin_lock(&dq_list_lock); 783 if (atomic_read(&dquot->dq_count) > 1) { 784 /* We have more than one user... nothing to do */ 785 atomic_dec(&dquot->dq_count); 786 /* Releasing dquot during quotaoff phase? */ 787 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 788 atomic_read(&dquot->dq_count) == 1) 789 wake_up(&dquot_ref_wq); 790 spin_unlock(&dq_list_lock); 791 return; 792 } 793 /* Need to release dquot? */ 794 if (dquot_dirty(dquot)) { 795 spin_unlock(&dq_list_lock); 796 /* Commit dquot before releasing */ 797 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 798 if (ret < 0) { 799 quota_error(dquot->dq_sb, "Can't write quota structure" 800 " (error %d). Quota may get out of sync!", 801 ret); 802 /* 803 * We clear dirty bit anyway, so that we avoid 804 * infinite loop here 805 */ 806 clear_dquot_dirty(dquot); 807 } 808 goto we_slept; 809 } 810 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 811 spin_unlock(&dq_list_lock); 812 dquot->dq_sb->dq_op->release_dquot(dquot); 813 goto we_slept; 814 } 815 atomic_dec(&dquot->dq_count); 816 #ifdef CONFIG_QUOTA_DEBUG 817 /* sanity check */ 818 BUG_ON(!list_empty(&dquot->dq_free)); 819 #endif 820 put_dquot_last(dquot); 821 spin_unlock(&dq_list_lock); 822 } 823 EXPORT_SYMBOL(dqput); 824 825 struct dquot *dquot_alloc(struct super_block *sb, int type) 826 { 827 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 828 } 829 EXPORT_SYMBOL(dquot_alloc); 830 831 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 832 { 833 struct dquot *dquot; 834 835 dquot = sb->dq_op->alloc_dquot(sb, type); 836 if(!dquot) 837 return NULL; 838 839 mutex_init(&dquot->dq_lock); 840 INIT_LIST_HEAD(&dquot->dq_free); 841 INIT_LIST_HEAD(&dquot->dq_inuse); 842 INIT_HLIST_NODE(&dquot->dq_hash); 843 INIT_LIST_HEAD(&dquot->dq_dirty); 844 dquot->dq_sb = sb; 845 dquot->dq_id = make_kqid_invalid(type); 846 atomic_set(&dquot->dq_count, 1); 847 spin_lock_init(&dquot->dq_dqb_lock); 848 849 return dquot; 850 } 851 852 /* 853 * Get reference to dquot 854 * 855 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 856 * destroying our dquot by: 857 * a) checking for quota flags under dq_list_lock and 858 * b) getting a reference to dquot before we release dq_list_lock 859 */ 860 struct dquot *dqget(struct super_block *sb, struct kqid qid) 861 { 862 unsigned int hashent = hashfn(sb, qid); 863 struct dquot *dquot, *empty = NULL; 864 865 if (!qid_has_mapping(sb->s_user_ns, qid)) 866 return ERR_PTR(-EINVAL); 867 868 if (!sb_has_quota_active(sb, qid.type)) 869 return ERR_PTR(-ESRCH); 870 we_slept: 871 spin_lock(&dq_list_lock); 872 spin_lock(&dq_state_lock); 873 if (!sb_has_quota_active(sb, qid.type)) { 874 spin_unlock(&dq_state_lock); 875 spin_unlock(&dq_list_lock); 876 dquot = ERR_PTR(-ESRCH); 877 goto out; 878 } 879 spin_unlock(&dq_state_lock); 880 881 dquot = find_dquot(hashent, sb, qid); 882 if (!dquot) { 883 if (!empty) { 884 spin_unlock(&dq_list_lock); 885 empty = get_empty_dquot(sb, qid.type); 886 if (!empty) 887 schedule(); /* Try to wait for a moment... */ 888 goto we_slept; 889 } 890 dquot = empty; 891 empty = NULL; 892 dquot->dq_id = qid; 893 /* all dquots go on the inuse_list */ 894 put_inuse(dquot); 895 /* hash it first so it can be found */ 896 insert_dquot_hash(dquot); 897 spin_unlock(&dq_list_lock); 898 dqstats_inc(DQST_LOOKUPS); 899 } else { 900 if (!atomic_read(&dquot->dq_count)) 901 remove_free_dquot(dquot); 902 atomic_inc(&dquot->dq_count); 903 spin_unlock(&dq_list_lock); 904 dqstats_inc(DQST_CACHE_HITS); 905 dqstats_inc(DQST_LOOKUPS); 906 } 907 /* Wait for dq_lock - after this we know that either dquot_release() is 908 * already finished or it will be canceled due to dq_count > 1 test */ 909 wait_on_dquot(dquot); 910 /* Read the dquot / allocate space in quota file */ 911 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 912 int err; 913 914 err = sb->dq_op->acquire_dquot(dquot); 915 if (err < 0) { 916 dqput(dquot); 917 dquot = ERR_PTR(err); 918 goto out; 919 } 920 } 921 /* 922 * Make sure following reads see filled structure - paired with 923 * smp_mb__before_atomic() in dquot_acquire(). 924 */ 925 smp_rmb(); 926 #ifdef CONFIG_QUOTA_DEBUG 927 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 928 #endif 929 out: 930 if (empty) 931 do_destroy_dquot(empty); 932 933 return dquot; 934 } 935 EXPORT_SYMBOL(dqget); 936 937 static inline struct dquot **i_dquot(struct inode *inode) 938 { 939 return inode->i_sb->s_op->get_dquots(inode); 940 } 941 942 static int dqinit_needed(struct inode *inode, int type) 943 { 944 struct dquot * const *dquots; 945 int cnt; 946 947 if (IS_NOQUOTA(inode)) 948 return 0; 949 950 dquots = i_dquot(inode); 951 if (type != -1) 952 return !dquots[type]; 953 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 954 if (!dquots[cnt]) 955 return 1; 956 return 0; 957 } 958 959 /* This routine is guarded by s_umount semaphore */ 960 static int add_dquot_ref(struct super_block *sb, int type) 961 { 962 struct inode *inode, *old_inode = NULL; 963 #ifdef CONFIG_QUOTA_DEBUG 964 int reserved = 0; 965 #endif 966 int err = 0; 967 968 spin_lock(&sb->s_inode_list_lock); 969 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 970 spin_lock(&inode->i_lock); 971 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 972 !atomic_read(&inode->i_writecount) || 973 !dqinit_needed(inode, type)) { 974 spin_unlock(&inode->i_lock); 975 continue; 976 } 977 __iget(inode); 978 spin_unlock(&inode->i_lock); 979 spin_unlock(&sb->s_inode_list_lock); 980 981 #ifdef CONFIG_QUOTA_DEBUG 982 if (unlikely(inode_get_rsv_space(inode) > 0)) 983 reserved = 1; 984 #endif 985 iput(old_inode); 986 err = __dquot_initialize(inode, type); 987 if (err) { 988 iput(inode); 989 goto out; 990 } 991 992 /* 993 * We hold a reference to 'inode' so it couldn't have been 994 * removed from s_inodes list while we dropped the 995 * s_inode_list_lock. We cannot iput the inode now as we can be 996 * holding the last reference and we cannot iput it under 997 * s_inode_list_lock. So we keep the reference and iput it 998 * later. 999 */ 1000 old_inode = inode; 1001 cond_resched(); 1002 spin_lock(&sb->s_inode_list_lock); 1003 } 1004 spin_unlock(&sb->s_inode_list_lock); 1005 iput(old_inode); 1006 out: 1007 #ifdef CONFIG_QUOTA_DEBUG 1008 if (reserved) { 1009 quota_error(sb, "Writes happened before quota was turned on " 1010 "thus quota information is probably inconsistent. " 1011 "Please run quotacheck(8)"); 1012 } 1013 #endif 1014 return err; 1015 } 1016 1017 /* 1018 * Remove references to dquots from inode and add dquot to list for freeing 1019 * if we have the last reference to dquot 1020 */ 1021 static void remove_inode_dquot_ref(struct inode *inode, int type, 1022 struct list_head *tofree_head) 1023 { 1024 struct dquot **dquots = i_dquot(inode); 1025 struct dquot *dquot = dquots[type]; 1026 1027 if (!dquot) 1028 return; 1029 1030 dquots[type] = NULL; 1031 if (list_empty(&dquot->dq_free)) { 1032 /* 1033 * The inode still has reference to dquot so it can't be in the 1034 * free list 1035 */ 1036 spin_lock(&dq_list_lock); 1037 list_add(&dquot->dq_free, tofree_head); 1038 spin_unlock(&dq_list_lock); 1039 } else { 1040 /* 1041 * Dquot is already in a list to put so we won't drop the last 1042 * reference here. 1043 */ 1044 dqput(dquot); 1045 } 1046 } 1047 1048 /* 1049 * Free list of dquots 1050 * Dquots are removed from inodes and no new references can be got so we are 1051 * the only ones holding reference 1052 */ 1053 static void put_dquot_list(struct list_head *tofree_head) 1054 { 1055 struct list_head *act_head; 1056 struct dquot *dquot; 1057 1058 act_head = tofree_head->next; 1059 while (act_head != tofree_head) { 1060 dquot = list_entry(act_head, struct dquot, dq_free); 1061 act_head = act_head->next; 1062 /* Remove dquot from the list so we won't have problems... */ 1063 list_del_init(&dquot->dq_free); 1064 dqput(dquot); 1065 } 1066 } 1067 1068 static void remove_dquot_ref(struct super_block *sb, int type, 1069 struct list_head *tofree_head) 1070 { 1071 struct inode *inode; 1072 #ifdef CONFIG_QUOTA_DEBUG 1073 int reserved = 0; 1074 #endif 1075 1076 spin_lock(&sb->s_inode_list_lock); 1077 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1078 /* 1079 * We have to scan also I_NEW inodes because they can already 1080 * have quota pointer initialized. Luckily, we need to touch 1081 * only quota pointers and these have separate locking 1082 * (dq_data_lock). 1083 */ 1084 spin_lock(&dq_data_lock); 1085 if (!IS_NOQUOTA(inode)) { 1086 #ifdef CONFIG_QUOTA_DEBUG 1087 if (unlikely(inode_get_rsv_space(inode) > 0)) 1088 reserved = 1; 1089 #endif 1090 remove_inode_dquot_ref(inode, type, tofree_head); 1091 } 1092 spin_unlock(&dq_data_lock); 1093 } 1094 spin_unlock(&sb->s_inode_list_lock); 1095 #ifdef CONFIG_QUOTA_DEBUG 1096 if (reserved) { 1097 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1098 " was disabled thus quota information is probably " 1099 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1100 } 1101 #endif 1102 } 1103 1104 /* Gather all references from inodes and drop them */ 1105 static void drop_dquot_ref(struct super_block *sb, int type) 1106 { 1107 LIST_HEAD(tofree_head); 1108 1109 if (sb->dq_op) { 1110 remove_dquot_ref(sb, type, &tofree_head); 1111 synchronize_srcu(&dquot_srcu); 1112 put_dquot_list(&tofree_head); 1113 } 1114 } 1115 1116 static inline 1117 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1118 { 1119 if (dquot->dq_dqb.dqb_rsvspace >= number) 1120 dquot->dq_dqb.dqb_rsvspace -= number; 1121 else { 1122 WARN_ON_ONCE(1); 1123 dquot->dq_dqb.dqb_rsvspace = 0; 1124 } 1125 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1126 dquot->dq_dqb.dqb_bsoftlimit) 1127 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1128 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1129 } 1130 1131 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1132 { 1133 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1134 dquot->dq_dqb.dqb_curinodes >= number) 1135 dquot->dq_dqb.dqb_curinodes -= number; 1136 else 1137 dquot->dq_dqb.dqb_curinodes = 0; 1138 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1139 dquot->dq_dqb.dqb_itime = (time64_t) 0; 1140 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1141 } 1142 1143 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1144 { 1145 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1146 dquot->dq_dqb.dqb_curspace >= number) 1147 dquot->dq_dqb.dqb_curspace -= number; 1148 else 1149 dquot->dq_dqb.dqb_curspace = 0; 1150 if (dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace <= 1151 dquot->dq_dqb.dqb_bsoftlimit) 1152 dquot->dq_dqb.dqb_btime = (time64_t) 0; 1153 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1154 } 1155 1156 struct dquot_warn { 1157 struct super_block *w_sb; 1158 struct kqid w_dq_id; 1159 short w_type; 1160 }; 1161 1162 static int warning_issued(struct dquot *dquot, const int warntype) 1163 { 1164 int flag = (warntype == QUOTA_NL_BHARDWARN || 1165 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1166 ((warntype == QUOTA_NL_IHARDWARN || 1167 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1168 1169 if (!flag) 1170 return 0; 1171 return test_and_set_bit(flag, &dquot->dq_flags); 1172 } 1173 1174 #ifdef CONFIG_PRINT_QUOTA_WARNING 1175 static int flag_print_warnings = 1; 1176 1177 static int need_print_warning(struct dquot_warn *warn) 1178 { 1179 if (!flag_print_warnings) 1180 return 0; 1181 1182 switch (warn->w_dq_id.type) { 1183 case USRQUOTA: 1184 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1185 case GRPQUOTA: 1186 return in_group_p(warn->w_dq_id.gid); 1187 case PRJQUOTA: 1188 return 1; 1189 } 1190 return 0; 1191 } 1192 1193 /* Print warning to user which exceeded quota */ 1194 static void print_warning(struct dquot_warn *warn) 1195 { 1196 char *msg = NULL; 1197 struct tty_struct *tty; 1198 int warntype = warn->w_type; 1199 1200 if (warntype == QUOTA_NL_IHARDBELOW || 1201 warntype == QUOTA_NL_ISOFTBELOW || 1202 warntype == QUOTA_NL_BHARDBELOW || 1203 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1204 return; 1205 1206 tty = get_current_tty(); 1207 if (!tty) 1208 return; 1209 tty_write_message(tty, warn->w_sb->s_id); 1210 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1211 tty_write_message(tty, ": warning, "); 1212 else 1213 tty_write_message(tty, ": write failed, "); 1214 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1215 switch (warntype) { 1216 case QUOTA_NL_IHARDWARN: 1217 msg = " file limit reached.\r\n"; 1218 break; 1219 case QUOTA_NL_ISOFTLONGWARN: 1220 msg = " file quota exceeded too long.\r\n"; 1221 break; 1222 case QUOTA_NL_ISOFTWARN: 1223 msg = " file quota exceeded.\r\n"; 1224 break; 1225 case QUOTA_NL_BHARDWARN: 1226 msg = " block limit reached.\r\n"; 1227 break; 1228 case QUOTA_NL_BSOFTLONGWARN: 1229 msg = " block quota exceeded too long.\r\n"; 1230 break; 1231 case QUOTA_NL_BSOFTWARN: 1232 msg = " block quota exceeded.\r\n"; 1233 break; 1234 } 1235 tty_write_message(tty, msg); 1236 tty_kref_put(tty); 1237 } 1238 #endif 1239 1240 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1241 int warntype) 1242 { 1243 if (warning_issued(dquot, warntype)) 1244 return; 1245 warn->w_type = warntype; 1246 warn->w_sb = dquot->dq_sb; 1247 warn->w_dq_id = dquot->dq_id; 1248 } 1249 1250 /* 1251 * Write warnings to the console and send warning messages over netlink. 1252 * 1253 * Note that this function can call into tty and networking code. 1254 */ 1255 static void flush_warnings(struct dquot_warn *warn) 1256 { 1257 int i; 1258 1259 for (i = 0; i < MAXQUOTAS; i++) { 1260 if (warn[i].w_type == QUOTA_NL_NOWARN) 1261 continue; 1262 #ifdef CONFIG_PRINT_QUOTA_WARNING 1263 print_warning(&warn[i]); 1264 #endif 1265 quota_send_warning(warn[i].w_dq_id, 1266 warn[i].w_sb->s_dev, warn[i].w_type); 1267 } 1268 } 1269 1270 static int ignore_hardlimit(struct dquot *dquot) 1271 { 1272 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1273 1274 return capable(CAP_SYS_RESOURCE) && 1275 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1276 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1277 } 1278 1279 static int dquot_add_inodes(struct dquot *dquot, qsize_t inodes, 1280 struct dquot_warn *warn) 1281 { 1282 qsize_t newinodes; 1283 int ret = 0; 1284 1285 spin_lock(&dquot->dq_dqb_lock); 1286 newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1287 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1288 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1289 goto add; 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 ret = -EDQUOT; 1296 goto out; 1297 } 1298 1299 if (dquot->dq_dqb.dqb_isoftlimit && 1300 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1301 dquot->dq_dqb.dqb_itime && 1302 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_itime && 1303 !ignore_hardlimit(dquot)) { 1304 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1305 ret = -EDQUOT; 1306 goto out; 1307 } 1308 1309 if (dquot->dq_dqb.dqb_isoftlimit && 1310 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1311 dquot->dq_dqb.dqb_itime == 0) { 1312 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1313 dquot->dq_dqb.dqb_itime = ktime_get_real_seconds() + 1314 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1315 } 1316 add: 1317 dquot->dq_dqb.dqb_curinodes = newinodes; 1318 1319 out: 1320 spin_unlock(&dquot->dq_dqb_lock); 1321 return ret; 1322 } 1323 1324 static int dquot_add_space(struct dquot *dquot, qsize_t space, 1325 qsize_t rsv_space, unsigned int flags, 1326 struct dquot_warn *warn) 1327 { 1328 qsize_t tspace; 1329 struct super_block *sb = dquot->dq_sb; 1330 int ret = 0; 1331 1332 spin_lock(&dquot->dq_dqb_lock); 1333 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1334 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1335 goto finish; 1336 1337 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1338 + space + rsv_space; 1339 1340 if (dquot->dq_dqb.dqb_bhardlimit && 1341 tspace > dquot->dq_dqb.dqb_bhardlimit && 1342 !ignore_hardlimit(dquot)) { 1343 if (flags & DQUOT_SPACE_WARN) 1344 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1345 ret = -EDQUOT; 1346 goto finish; 1347 } 1348 1349 if (dquot->dq_dqb.dqb_bsoftlimit && 1350 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1351 dquot->dq_dqb.dqb_btime && 1352 ktime_get_real_seconds() >= dquot->dq_dqb.dqb_btime && 1353 !ignore_hardlimit(dquot)) { 1354 if (flags & DQUOT_SPACE_WARN) 1355 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1356 ret = -EDQUOT; 1357 goto finish; 1358 } 1359 1360 if (dquot->dq_dqb.dqb_bsoftlimit && 1361 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1362 dquot->dq_dqb.dqb_btime == 0) { 1363 if (flags & DQUOT_SPACE_WARN) { 1364 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1365 dquot->dq_dqb.dqb_btime = ktime_get_real_seconds() + 1366 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1367 } else { 1368 /* 1369 * We don't allow preallocation to exceed softlimit so exceeding will 1370 * be always printed 1371 */ 1372 ret = -EDQUOT; 1373 goto finish; 1374 } 1375 } 1376 finish: 1377 /* 1378 * We have to be careful and go through warning generation & grace time 1379 * setting even if DQUOT_SPACE_NOFAIL is set. That's why we check it 1380 * only here... 1381 */ 1382 if (flags & DQUOT_SPACE_NOFAIL) 1383 ret = 0; 1384 if (!ret) { 1385 dquot->dq_dqb.dqb_rsvspace += rsv_space; 1386 dquot->dq_dqb.dqb_curspace += space; 1387 } 1388 spin_unlock(&dquot->dq_dqb_lock); 1389 return ret; 1390 } 1391 1392 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1393 { 1394 qsize_t newinodes; 1395 1396 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1397 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1398 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1399 return QUOTA_NL_NOWARN; 1400 1401 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1402 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1403 return QUOTA_NL_ISOFTBELOW; 1404 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1405 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1406 return QUOTA_NL_IHARDBELOW; 1407 return QUOTA_NL_NOWARN; 1408 } 1409 1410 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1411 { 1412 qsize_t tspace; 1413 1414 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace; 1415 1416 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1417 tspace <= dquot->dq_dqb.dqb_bsoftlimit) 1418 return QUOTA_NL_NOWARN; 1419 1420 if (tspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1421 return QUOTA_NL_BSOFTBELOW; 1422 if (tspace >= dquot->dq_dqb.dqb_bhardlimit && 1423 tspace - space < dquot->dq_dqb.dqb_bhardlimit) 1424 return QUOTA_NL_BHARDBELOW; 1425 return QUOTA_NL_NOWARN; 1426 } 1427 1428 static int dquot_active(const struct inode *inode) 1429 { 1430 struct super_block *sb = inode->i_sb; 1431 1432 if (IS_NOQUOTA(inode)) 1433 return 0; 1434 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1435 } 1436 1437 /* 1438 * Initialize quota pointers in inode 1439 * 1440 * It is better to call this function outside of any transaction as it 1441 * might need a lot of space in journal for dquot structure allocation. 1442 */ 1443 static int __dquot_initialize(struct inode *inode, int type) 1444 { 1445 int cnt, init_needed = 0; 1446 struct dquot **dquots, *got[MAXQUOTAS] = {}; 1447 struct super_block *sb = inode->i_sb; 1448 qsize_t rsv; 1449 int ret = 0; 1450 1451 if (!dquot_active(inode)) 1452 return 0; 1453 1454 dquots = i_dquot(inode); 1455 1456 /* First get references to structures we might need. */ 1457 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1458 struct kqid qid; 1459 kprojid_t projid; 1460 int rc; 1461 struct dquot *dquot; 1462 1463 if (type != -1 && cnt != type) 1464 continue; 1465 /* 1466 * The i_dquot should have been initialized in most cases, 1467 * we check it without locking here to avoid unnecessary 1468 * dqget()/dqput() calls. 1469 */ 1470 if (dquots[cnt]) 1471 continue; 1472 1473 if (!sb_has_quota_active(sb, cnt)) 1474 continue; 1475 1476 init_needed = 1; 1477 1478 switch (cnt) { 1479 case USRQUOTA: 1480 qid = make_kqid_uid(inode->i_uid); 1481 break; 1482 case GRPQUOTA: 1483 qid = make_kqid_gid(inode->i_gid); 1484 break; 1485 case PRJQUOTA: 1486 rc = inode->i_sb->dq_op->get_projid(inode, &projid); 1487 if (rc) 1488 continue; 1489 qid = make_kqid_projid(projid); 1490 break; 1491 } 1492 dquot = dqget(sb, qid); 1493 if (IS_ERR(dquot)) { 1494 /* We raced with somebody turning quotas off... */ 1495 if (PTR_ERR(dquot) != -ESRCH) { 1496 ret = PTR_ERR(dquot); 1497 goto out_put; 1498 } 1499 dquot = NULL; 1500 } 1501 got[cnt] = dquot; 1502 } 1503 1504 /* All required i_dquot has been initialized */ 1505 if (!init_needed) 1506 return 0; 1507 1508 spin_lock(&dq_data_lock); 1509 if (IS_NOQUOTA(inode)) 1510 goto out_lock; 1511 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1512 if (type != -1 && cnt != type) 1513 continue; 1514 /* Avoid races with quotaoff() */ 1515 if (!sb_has_quota_active(sb, cnt)) 1516 continue; 1517 /* We could race with quotaon or dqget() could have failed */ 1518 if (!got[cnt]) 1519 continue; 1520 if (!dquots[cnt]) { 1521 dquots[cnt] = got[cnt]; 1522 got[cnt] = NULL; 1523 /* 1524 * Make quota reservation system happy if someone 1525 * did a write before quota was turned on 1526 */ 1527 rsv = inode_get_rsv_space(inode); 1528 if (unlikely(rsv)) { 1529 spin_lock(&inode->i_lock); 1530 /* Get reservation again under proper lock */ 1531 rsv = __inode_get_rsv_space(inode); 1532 spin_lock(&dquots[cnt]->dq_dqb_lock); 1533 dquots[cnt]->dq_dqb.dqb_rsvspace += rsv; 1534 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1535 spin_unlock(&inode->i_lock); 1536 } 1537 } 1538 } 1539 out_lock: 1540 spin_unlock(&dq_data_lock); 1541 out_put: 1542 /* Drop unused references */ 1543 dqput_all(got); 1544 1545 return ret; 1546 } 1547 1548 int dquot_initialize(struct inode *inode) 1549 { 1550 return __dquot_initialize(inode, -1); 1551 } 1552 EXPORT_SYMBOL(dquot_initialize); 1553 1554 bool dquot_initialize_needed(struct inode *inode) 1555 { 1556 struct dquot **dquots; 1557 int i; 1558 1559 if (!dquot_active(inode)) 1560 return false; 1561 1562 dquots = i_dquot(inode); 1563 for (i = 0; i < MAXQUOTAS; i++) 1564 if (!dquots[i] && sb_has_quota_active(inode->i_sb, i)) 1565 return true; 1566 return false; 1567 } 1568 EXPORT_SYMBOL(dquot_initialize_needed); 1569 1570 /* 1571 * Release all quotas referenced by inode. 1572 * 1573 * This function only be called on inode free or converting 1574 * a file to quota file, no other users for the i_dquot in 1575 * both cases, so we needn't call synchronize_srcu() after 1576 * clearing i_dquot. 1577 */ 1578 static void __dquot_drop(struct inode *inode) 1579 { 1580 int cnt; 1581 struct dquot **dquots = i_dquot(inode); 1582 struct dquot *put[MAXQUOTAS]; 1583 1584 spin_lock(&dq_data_lock); 1585 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1586 put[cnt] = dquots[cnt]; 1587 dquots[cnt] = NULL; 1588 } 1589 spin_unlock(&dq_data_lock); 1590 dqput_all(put); 1591 } 1592 1593 void dquot_drop(struct inode *inode) 1594 { 1595 struct dquot * const *dquots; 1596 int cnt; 1597 1598 if (IS_NOQUOTA(inode)) 1599 return; 1600 1601 /* 1602 * Test before calling to rule out calls from proc and such 1603 * where we are not allowed to block. Note that this is 1604 * actually reliable test even without the lock - the caller 1605 * must assure that nobody can come after the DQUOT_DROP and 1606 * add quota pointers back anyway. 1607 */ 1608 dquots = i_dquot(inode); 1609 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1610 if (dquots[cnt]) 1611 break; 1612 } 1613 1614 if (cnt < MAXQUOTAS) 1615 __dquot_drop(inode); 1616 } 1617 EXPORT_SYMBOL(dquot_drop); 1618 1619 /* 1620 * inode_reserved_space is managed internally by quota, and protected by 1621 * i_lock similar to i_blocks+i_bytes. 1622 */ 1623 static qsize_t *inode_reserved_space(struct inode * inode) 1624 { 1625 /* Filesystem must explicitly define it's own method in order to use 1626 * quota reservation interface */ 1627 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1628 return inode->i_sb->dq_op->get_reserved_space(inode); 1629 } 1630 1631 static qsize_t __inode_get_rsv_space(struct inode *inode) 1632 { 1633 if (!inode->i_sb->dq_op->get_reserved_space) 1634 return 0; 1635 return *inode_reserved_space(inode); 1636 } 1637 1638 static qsize_t inode_get_rsv_space(struct inode *inode) 1639 { 1640 qsize_t ret; 1641 1642 if (!inode->i_sb->dq_op->get_reserved_space) 1643 return 0; 1644 spin_lock(&inode->i_lock); 1645 ret = __inode_get_rsv_space(inode); 1646 spin_unlock(&inode->i_lock); 1647 return ret; 1648 } 1649 1650 /* 1651 * This functions updates i_blocks+i_bytes fields and quota information 1652 * (together with appropriate checks). 1653 * 1654 * NOTE: We absolutely rely on the fact that caller dirties the inode 1655 * (usually helpers in quotaops.h care about this) and holds a handle for 1656 * the current transaction so that dquot write and inode write go into the 1657 * same transaction. 1658 */ 1659 1660 /* 1661 * This operation can block, but only after everything is updated 1662 */ 1663 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1664 { 1665 int cnt, ret = 0, index; 1666 struct dquot_warn warn[MAXQUOTAS]; 1667 int reserve = flags & DQUOT_SPACE_RESERVE; 1668 struct dquot **dquots; 1669 1670 if (!dquot_active(inode)) { 1671 if (reserve) { 1672 spin_lock(&inode->i_lock); 1673 *inode_reserved_space(inode) += number; 1674 spin_unlock(&inode->i_lock); 1675 } else { 1676 inode_add_bytes(inode, number); 1677 } 1678 goto out; 1679 } 1680 1681 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1682 warn[cnt].w_type = QUOTA_NL_NOWARN; 1683 1684 dquots = i_dquot(inode); 1685 index = srcu_read_lock(&dquot_srcu); 1686 spin_lock(&inode->i_lock); 1687 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1688 if (!dquots[cnt]) 1689 continue; 1690 if (reserve) { 1691 ret = dquot_add_space(dquots[cnt], 0, number, flags, 1692 &warn[cnt]); 1693 } else { 1694 ret = dquot_add_space(dquots[cnt], number, 0, flags, 1695 &warn[cnt]); 1696 } 1697 if (ret) { 1698 /* Back out changes we already did */ 1699 for (cnt--; cnt >= 0; cnt--) { 1700 if (!dquots[cnt]) 1701 continue; 1702 spin_lock(&dquots[cnt]->dq_dqb_lock); 1703 if (reserve) 1704 dquot_free_reserved_space(dquots[cnt], 1705 number); 1706 else 1707 dquot_decr_space(dquots[cnt], number); 1708 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1709 } 1710 spin_unlock(&inode->i_lock); 1711 goto out_flush_warn; 1712 } 1713 } 1714 if (reserve) 1715 *inode_reserved_space(inode) += number; 1716 else 1717 __inode_add_bytes(inode, number); 1718 spin_unlock(&inode->i_lock); 1719 1720 if (reserve) 1721 goto out_flush_warn; 1722 mark_all_dquot_dirty(dquots); 1723 out_flush_warn: 1724 srcu_read_unlock(&dquot_srcu, index); 1725 flush_warnings(warn); 1726 out: 1727 return ret; 1728 } 1729 EXPORT_SYMBOL(__dquot_alloc_space); 1730 1731 /* 1732 * This operation can block, but only after everything is updated 1733 */ 1734 int dquot_alloc_inode(struct inode *inode) 1735 { 1736 int cnt, ret = 0, index; 1737 struct dquot_warn warn[MAXQUOTAS]; 1738 struct dquot * const *dquots; 1739 1740 if (!dquot_active(inode)) 1741 return 0; 1742 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1743 warn[cnt].w_type = QUOTA_NL_NOWARN; 1744 1745 dquots = i_dquot(inode); 1746 index = srcu_read_lock(&dquot_srcu); 1747 spin_lock(&inode->i_lock); 1748 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1749 if (!dquots[cnt]) 1750 continue; 1751 ret = dquot_add_inodes(dquots[cnt], 1, &warn[cnt]); 1752 if (ret) { 1753 for (cnt--; cnt >= 0; cnt--) { 1754 if (!dquots[cnt]) 1755 continue; 1756 /* Back out changes we already did */ 1757 spin_lock(&dquots[cnt]->dq_dqb_lock); 1758 dquot_decr_inodes(dquots[cnt], 1); 1759 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1760 } 1761 goto warn_put_all; 1762 } 1763 } 1764 1765 warn_put_all: 1766 spin_unlock(&inode->i_lock); 1767 if (ret == 0) 1768 mark_all_dquot_dirty(dquots); 1769 srcu_read_unlock(&dquot_srcu, index); 1770 flush_warnings(warn); 1771 return ret; 1772 } 1773 EXPORT_SYMBOL(dquot_alloc_inode); 1774 1775 /* 1776 * Convert in-memory reserved quotas to real consumed quotas 1777 */ 1778 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1779 { 1780 struct dquot **dquots; 1781 int cnt, index; 1782 1783 if (!dquot_active(inode)) { 1784 spin_lock(&inode->i_lock); 1785 *inode_reserved_space(inode) -= number; 1786 __inode_add_bytes(inode, number); 1787 spin_unlock(&inode->i_lock); 1788 return 0; 1789 } 1790 1791 dquots = i_dquot(inode); 1792 index = srcu_read_lock(&dquot_srcu); 1793 spin_lock(&inode->i_lock); 1794 /* Claim reserved quotas to allocated quotas */ 1795 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1796 if (dquots[cnt]) { 1797 struct dquot *dquot = dquots[cnt]; 1798 1799 spin_lock(&dquot->dq_dqb_lock); 1800 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_rsvspace < number)) 1801 number = dquot->dq_dqb.dqb_rsvspace; 1802 dquot->dq_dqb.dqb_curspace += number; 1803 dquot->dq_dqb.dqb_rsvspace -= number; 1804 spin_unlock(&dquot->dq_dqb_lock); 1805 } 1806 } 1807 /* Update inode bytes */ 1808 *inode_reserved_space(inode) -= number; 1809 __inode_add_bytes(inode, number); 1810 spin_unlock(&inode->i_lock); 1811 mark_all_dquot_dirty(dquots); 1812 srcu_read_unlock(&dquot_srcu, index); 1813 return 0; 1814 } 1815 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1816 1817 /* 1818 * Convert allocated space back to in-memory reserved quotas 1819 */ 1820 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1821 { 1822 struct dquot **dquots; 1823 int cnt, index; 1824 1825 if (!dquot_active(inode)) { 1826 spin_lock(&inode->i_lock); 1827 *inode_reserved_space(inode) += number; 1828 __inode_sub_bytes(inode, number); 1829 spin_unlock(&inode->i_lock); 1830 return; 1831 } 1832 1833 dquots = i_dquot(inode); 1834 index = srcu_read_lock(&dquot_srcu); 1835 spin_lock(&inode->i_lock); 1836 /* Claim reserved quotas to allocated quotas */ 1837 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1838 if (dquots[cnt]) { 1839 struct dquot *dquot = dquots[cnt]; 1840 1841 spin_lock(&dquot->dq_dqb_lock); 1842 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1843 number = dquot->dq_dqb.dqb_curspace; 1844 dquot->dq_dqb.dqb_rsvspace += number; 1845 dquot->dq_dqb.dqb_curspace -= number; 1846 spin_unlock(&dquot->dq_dqb_lock); 1847 } 1848 } 1849 /* Update inode bytes */ 1850 *inode_reserved_space(inode) += number; 1851 __inode_sub_bytes(inode, number); 1852 spin_unlock(&inode->i_lock); 1853 mark_all_dquot_dirty(dquots); 1854 srcu_read_unlock(&dquot_srcu, index); 1855 return; 1856 } 1857 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1858 1859 /* 1860 * This operation can block, but only after everything is updated 1861 */ 1862 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1863 { 1864 unsigned int cnt; 1865 struct dquot_warn warn[MAXQUOTAS]; 1866 struct dquot **dquots; 1867 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1868 1869 if (!dquot_active(inode)) { 1870 if (reserve) { 1871 spin_lock(&inode->i_lock); 1872 *inode_reserved_space(inode) -= number; 1873 spin_unlock(&inode->i_lock); 1874 } else { 1875 inode_sub_bytes(inode, number); 1876 } 1877 return; 1878 } 1879 1880 dquots = i_dquot(inode); 1881 index = srcu_read_lock(&dquot_srcu); 1882 spin_lock(&inode->i_lock); 1883 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1884 int wtype; 1885 1886 warn[cnt].w_type = QUOTA_NL_NOWARN; 1887 if (!dquots[cnt]) 1888 continue; 1889 spin_lock(&dquots[cnt]->dq_dqb_lock); 1890 wtype = info_bdq_free(dquots[cnt], number); 1891 if (wtype != QUOTA_NL_NOWARN) 1892 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1893 if (reserve) 1894 dquot_free_reserved_space(dquots[cnt], number); 1895 else 1896 dquot_decr_space(dquots[cnt], number); 1897 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1898 } 1899 if (reserve) 1900 *inode_reserved_space(inode) -= number; 1901 else 1902 __inode_sub_bytes(inode, number); 1903 spin_unlock(&inode->i_lock); 1904 1905 if (reserve) 1906 goto out_unlock; 1907 mark_all_dquot_dirty(dquots); 1908 out_unlock: 1909 srcu_read_unlock(&dquot_srcu, index); 1910 flush_warnings(warn); 1911 } 1912 EXPORT_SYMBOL(__dquot_free_space); 1913 1914 /* 1915 * This operation can block, but only after everything is updated 1916 */ 1917 void dquot_free_inode(struct inode *inode) 1918 { 1919 unsigned int cnt; 1920 struct dquot_warn warn[MAXQUOTAS]; 1921 struct dquot * const *dquots; 1922 int index; 1923 1924 if (!dquot_active(inode)) 1925 return; 1926 1927 dquots = i_dquot(inode); 1928 index = srcu_read_lock(&dquot_srcu); 1929 spin_lock(&inode->i_lock); 1930 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1931 int wtype; 1932 1933 warn[cnt].w_type = QUOTA_NL_NOWARN; 1934 if (!dquots[cnt]) 1935 continue; 1936 spin_lock(&dquots[cnt]->dq_dqb_lock); 1937 wtype = info_idq_free(dquots[cnt], 1); 1938 if (wtype != QUOTA_NL_NOWARN) 1939 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1940 dquot_decr_inodes(dquots[cnt], 1); 1941 spin_unlock(&dquots[cnt]->dq_dqb_lock); 1942 } 1943 spin_unlock(&inode->i_lock); 1944 mark_all_dquot_dirty(dquots); 1945 srcu_read_unlock(&dquot_srcu, index); 1946 flush_warnings(warn); 1947 } 1948 EXPORT_SYMBOL(dquot_free_inode); 1949 1950 /* 1951 * Transfer the number of inode and blocks from one diskquota to an other. 1952 * On success, dquot references in transfer_to are consumed and references 1953 * to original dquots that need to be released are placed there. On failure, 1954 * references are kept untouched. 1955 * 1956 * This operation can block, but only after everything is updated 1957 * A transaction must be started when entering this function. 1958 * 1959 * We are holding reference on transfer_from & transfer_to, no need to 1960 * protect them by srcu_read_lock(). 1961 */ 1962 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1963 { 1964 qsize_t cur_space; 1965 qsize_t rsv_space = 0; 1966 qsize_t inode_usage = 1; 1967 struct dquot *transfer_from[MAXQUOTAS] = {}; 1968 int cnt, ret = 0; 1969 char is_valid[MAXQUOTAS] = {}; 1970 struct dquot_warn warn_to[MAXQUOTAS]; 1971 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1972 struct dquot_warn warn_from_space[MAXQUOTAS]; 1973 1974 if (IS_NOQUOTA(inode)) 1975 return 0; 1976 1977 if (inode->i_sb->dq_op->get_inode_usage) { 1978 ret = inode->i_sb->dq_op->get_inode_usage(inode, &inode_usage); 1979 if (ret) 1980 return ret; 1981 } 1982 1983 /* Initialize the arrays */ 1984 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1985 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1986 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1987 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1988 } 1989 1990 spin_lock(&dq_data_lock); 1991 spin_lock(&inode->i_lock); 1992 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1993 spin_unlock(&inode->i_lock); 1994 spin_unlock(&dq_data_lock); 1995 return 0; 1996 } 1997 cur_space = __inode_get_bytes(inode); 1998 rsv_space = __inode_get_rsv_space(inode); 1999 /* 2000 * Build the transfer_from list, check limits, and update usage in 2001 * the target structures. 2002 */ 2003 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2004 /* 2005 * Skip changes for same uid or gid or for turned off quota-type. 2006 */ 2007 if (!transfer_to[cnt]) 2008 continue; 2009 /* Avoid races with quotaoff() */ 2010 if (!sb_has_quota_active(inode->i_sb, cnt)) 2011 continue; 2012 is_valid[cnt] = 1; 2013 transfer_from[cnt] = i_dquot(inode)[cnt]; 2014 ret = dquot_add_inodes(transfer_to[cnt], inode_usage, 2015 &warn_to[cnt]); 2016 if (ret) 2017 goto over_quota; 2018 ret = dquot_add_space(transfer_to[cnt], cur_space, rsv_space, 2019 DQUOT_SPACE_WARN, &warn_to[cnt]); 2020 if (ret) { 2021 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2022 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2023 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2024 goto over_quota; 2025 } 2026 } 2027 2028 /* Decrease usage for source structures and update quota pointers */ 2029 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2030 if (!is_valid[cnt]) 2031 continue; 2032 /* Due to IO error we might not have transfer_from[] structure */ 2033 if (transfer_from[cnt]) { 2034 int wtype; 2035 2036 spin_lock(&transfer_from[cnt]->dq_dqb_lock); 2037 wtype = info_idq_free(transfer_from[cnt], inode_usage); 2038 if (wtype != QUOTA_NL_NOWARN) 2039 prepare_warning(&warn_from_inodes[cnt], 2040 transfer_from[cnt], wtype); 2041 wtype = info_bdq_free(transfer_from[cnt], 2042 cur_space + rsv_space); 2043 if (wtype != QUOTA_NL_NOWARN) 2044 prepare_warning(&warn_from_space[cnt], 2045 transfer_from[cnt], wtype); 2046 dquot_decr_inodes(transfer_from[cnt], inode_usage); 2047 dquot_decr_space(transfer_from[cnt], cur_space); 2048 dquot_free_reserved_space(transfer_from[cnt], 2049 rsv_space); 2050 spin_unlock(&transfer_from[cnt]->dq_dqb_lock); 2051 } 2052 i_dquot(inode)[cnt] = transfer_to[cnt]; 2053 } 2054 spin_unlock(&inode->i_lock); 2055 spin_unlock(&dq_data_lock); 2056 2057 mark_all_dquot_dirty(transfer_from); 2058 mark_all_dquot_dirty(transfer_to); 2059 flush_warnings(warn_to); 2060 flush_warnings(warn_from_inodes); 2061 flush_warnings(warn_from_space); 2062 /* Pass back references to put */ 2063 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2064 if (is_valid[cnt]) 2065 transfer_to[cnt] = transfer_from[cnt]; 2066 return 0; 2067 over_quota: 2068 /* Back out changes we already did */ 2069 for (cnt--; cnt >= 0; cnt--) { 2070 if (!is_valid[cnt]) 2071 continue; 2072 spin_lock(&transfer_to[cnt]->dq_dqb_lock); 2073 dquot_decr_inodes(transfer_to[cnt], inode_usage); 2074 dquot_decr_space(transfer_to[cnt], cur_space); 2075 dquot_free_reserved_space(transfer_to[cnt], rsv_space); 2076 spin_unlock(&transfer_to[cnt]->dq_dqb_lock); 2077 } 2078 spin_unlock(&inode->i_lock); 2079 spin_unlock(&dq_data_lock); 2080 flush_warnings(warn_to); 2081 return ret; 2082 } 2083 EXPORT_SYMBOL(__dquot_transfer); 2084 2085 /* Wrapper for transferring ownership of an inode for uid/gid only 2086 * Called from FSXXX_setattr() 2087 */ 2088 int dquot_transfer(struct inode *inode, struct iattr *iattr) 2089 { 2090 struct dquot *transfer_to[MAXQUOTAS] = {}; 2091 struct dquot *dquot; 2092 struct super_block *sb = inode->i_sb; 2093 int ret; 2094 2095 if (!dquot_active(inode)) 2096 return 0; 2097 2098 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)){ 2099 dquot = dqget(sb, make_kqid_uid(iattr->ia_uid)); 2100 if (IS_ERR(dquot)) { 2101 if (PTR_ERR(dquot) != -ESRCH) { 2102 ret = PTR_ERR(dquot); 2103 goto out_put; 2104 } 2105 dquot = NULL; 2106 } 2107 transfer_to[USRQUOTA] = dquot; 2108 } 2109 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)){ 2110 dquot = dqget(sb, make_kqid_gid(iattr->ia_gid)); 2111 if (IS_ERR(dquot)) { 2112 if (PTR_ERR(dquot) != -ESRCH) { 2113 ret = PTR_ERR(dquot); 2114 goto out_put; 2115 } 2116 dquot = NULL; 2117 } 2118 transfer_to[GRPQUOTA] = dquot; 2119 } 2120 ret = __dquot_transfer(inode, transfer_to); 2121 out_put: 2122 dqput_all(transfer_to); 2123 return ret; 2124 } 2125 EXPORT_SYMBOL(dquot_transfer); 2126 2127 /* 2128 * Write info of quota file to disk 2129 */ 2130 int dquot_commit_info(struct super_block *sb, int type) 2131 { 2132 struct quota_info *dqopt = sb_dqopt(sb); 2133 2134 return dqopt->ops[type]->write_file_info(sb, type); 2135 } 2136 EXPORT_SYMBOL(dquot_commit_info); 2137 2138 int dquot_get_next_id(struct super_block *sb, struct kqid *qid) 2139 { 2140 struct quota_info *dqopt = sb_dqopt(sb); 2141 2142 if (!sb_has_quota_active(sb, qid->type)) 2143 return -ESRCH; 2144 if (!dqopt->ops[qid->type]->get_next_id) 2145 return -ENOSYS; 2146 return dqopt->ops[qid->type]->get_next_id(sb, qid); 2147 } 2148 EXPORT_SYMBOL(dquot_get_next_id); 2149 2150 /* 2151 * Definitions of diskquota operations. 2152 */ 2153 const struct dquot_operations dquot_operations = { 2154 .write_dquot = dquot_commit, 2155 .acquire_dquot = dquot_acquire, 2156 .release_dquot = dquot_release, 2157 .mark_dirty = dquot_mark_dquot_dirty, 2158 .write_info = dquot_commit_info, 2159 .alloc_dquot = dquot_alloc, 2160 .destroy_dquot = dquot_destroy, 2161 .get_next_id = dquot_get_next_id, 2162 }; 2163 EXPORT_SYMBOL(dquot_operations); 2164 2165 /* 2166 * Generic helper for ->open on filesystems supporting disk quotas. 2167 */ 2168 int dquot_file_open(struct inode *inode, struct file *file) 2169 { 2170 int error; 2171 2172 error = generic_file_open(inode, file); 2173 if (!error && (file->f_mode & FMODE_WRITE)) 2174 error = dquot_initialize(inode); 2175 return error; 2176 } 2177 EXPORT_SYMBOL(dquot_file_open); 2178 2179 static void vfs_cleanup_quota_inode(struct super_block *sb, int type) 2180 { 2181 struct quota_info *dqopt = sb_dqopt(sb); 2182 struct inode *inode = dqopt->files[type]; 2183 2184 if (!inode) 2185 return; 2186 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2187 inode_lock(inode); 2188 inode->i_flags &= ~S_NOQUOTA; 2189 inode_unlock(inode); 2190 } 2191 dqopt->files[type] = NULL; 2192 iput(inode); 2193 } 2194 2195 /* 2196 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2197 */ 2198 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2199 { 2200 int cnt; 2201 struct quota_info *dqopt = sb_dqopt(sb); 2202 2203 /* s_umount should be held in exclusive mode */ 2204 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2205 up_read(&sb->s_umount); 2206 2207 /* Cannot turn off usage accounting without turning off limits, or 2208 * suspend quotas and simultaneously turn quotas off. */ 2209 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2210 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2211 DQUOT_USAGE_ENABLED))) 2212 return -EINVAL; 2213 2214 /* 2215 * Skip everything if there's nothing to do. We have to do this because 2216 * sometimes we are called when fill_super() failed and calling 2217 * sync_fs() in such cases does no good. 2218 */ 2219 if (!sb_any_quota_loaded(sb)) 2220 return 0; 2221 2222 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2223 if (type != -1 && cnt != type) 2224 continue; 2225 if (!sb_has_quota_loaded(sb, cnt)) 2226 continue; 2227 2228 if (flags & DQUOT_SUSPENDED) { 2229 spin_lock(&dq_state_lock); 2230 dqopt->flags |= 2231 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2232 spin_unlock(&dq_state_lock); 2233 } else { 2234 spin_lock(&dq_state_lock); 2235 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2236 /* Turning off suspended quotas? */ 2237 if (!sb_has_quota_loaded(sb, cnt) && 2238 sb_has_quota_suspended(sb, cnt)) { 2239 dqopt->flags &= ~dquot_state_flag( 2240 DQUOT_SUSPENDED, cnt); 2241 spin_unlock(&dq_state_lock); 2242 vfs_cleanup_quota_inode(sb, cnt); 2243 continue; 2244 } 2245 spin_unlock(&dq_state_lock); 2246 } 2247 2248 /* We still have to keep quota loaded? */ 2249 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2250 continue; 2251 2252 /* Note: these are blocking operations */ 2253 drop_dquot_ref(sb, cnt); 2254 invalidate_dquots(sb, cnt); 2255 /* 2256 * Now all dquots should be invalidated, all writes done so we 2257 * should be only users of the info. No locks needed. 2258 */ 2259 if (info_dirty(&dqopt->info[cnt])) 2260 sb->dq_op->write_info(sb, cnt); 2261 if (dqopt->ops[cnt]->free_file_info) 2262 dqopt->ops[cnt]->free_file_info(sb, cnt); 2263 put_quota_format(dqopt->info[cnt].dqi_format); 2264 dqopt->info[cnt].dqi_flags = 0; 2265 dqopt->info[cnt].dqi_igrace = 0; 2266 dqopt->info[cnt].dqi_bgrace = 0; 2267 dqopt->ops[cnt] = NULL; 2268 } 2269 2270 /* Skip syncing and setting flags if quota files are hidden */ 2271 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2272 goto put_inodes; 2273 2274 /* Sync the superblock so that buffers with quota data are written to 2275 * disk (and so userspace sees correct data afterwards). */ 2276 if (sb->s_op->sync_fs) 2277 sb->s_op->sync_fs(sb, 1); 2278 sync_blockdev(sb->s_bdev); 2279 /* Now the quota files are just ordinary files and we can set the 2280 * inode flags back. Moreover we discard the pagecache so that 2281 * userspace sees the writes we did bypassing the pagecache. We 2282 * must also discard the blockdev buffers so that we see the 2283 * changes done by userspace on the next quotaon() */ 2284 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2285 if (!sb_has_quota_loaded(sb, cnt) && dqopt->files[cnt]) { 2286 inode_lock(dqopt->files[cnt]); 2287 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 2288 inode_unlock(dqopt->files[cnt]); 2289 } 2290 if (sb->s_bdev) 2291 invalidate_bdev(sb->s_bdev); 2292 put_inodes: 2293 /* We are done when suspending quotas */ 2294 if (flags & DQUOT_SUSPENDED) 2295 return 0; 2296 2297 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2298 if (!sb_has_quota_loaded(sb, cnt)) 2299 vfs_cleanup_quota_inode(sb, cnt); 2300 return 0; 2301 } 2302 EXPORT_SYMBOL(dquot_disable); 2303 2304 int dquot_quota_off(struct super_block *sb, int type) 2305 { 2306 return dquot_disable(sb, type, 2307 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2308 } 2309 EXPORT_SYMBOL(dquot_quota_off); 2310 2311 /* 2312 * Turn quotas on on a device 2313 */ 2314 2315 static int vfs_setup_quota_inode(struct inode *inode, int type) 2316 { 2317 struct super_block *sb = inode->i_sb; 2318 struct quota_info *dqopt = sb_dqopt(sb); 2319 2320 if (!S_ISREG(inode->i_mode)) 2321 return -EACCES; 2322 if (IS_RDONLY(inode)) 2323 return -EROFS; 2324 if (sb_has_quota_loaded(sb, type)) 2325 return -EBUSY; 2326 2327 dqopt->files[type] = igrab(inode); 2328 if (!dqopt->files[type]) 2329 return -EIO; 2330 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2331 /* We don't want quota and atime on quota files (deadlocks 2332 * possible) Also nobody should write to the file - we use 2333 * special IO operations which ignore the immutable bit. */ 2334 inode_lock(inode); 2335 inode->i_flags |= S_NOQUOTA; 2336 inode_unlock(inode); 2337 /* 2338 * When S_NOQUOTA is set, remove dquot references as no more 2339 * references can be added 2340 */ 2341 __dquot_drop(inode); 2342 } 2343 return 0; 2344 } 2345 2346 int dquot_load_quota_sb(struct super_block *sb, int type, int format_id, 2347 unsigned int flags) 2348 { 2349 struct quota_format_type *fmt = find_quota_format(format_id); 2350 struct quota_info *dqopt = sb_dqopt(sb); 2351 int error; 2352 2353 /* Just unsuspend quotas? */ 2354 BUG_ON(flags & DQUOT_SUSPENDED); 2355 /* s_umount should be held in exclusive mode */ 2356 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2357 up_read(&sb->s_umount); 2358 2359 if (!fmt) 2360 return -ESRCH; 2361 if (!sb->s_op->quota_write || !sb->s_op->quota_read || 2362 (type == PRJQUOTA && sb->dq_op->get_projid == NULL)) { 2363 error = -EINVAL; 2364 goto out_fmt; 2365 } 2366 /* Filesystems outside of init_user_ns not yet supported */ 2367 if (sb->s_user_ns != &init_user_ns) { 2368 error = -EINVAL; 2369 goto out_fmt; 2370 } 2371 /* Usage always has to be set... */ 2372 if (!(flags & DQUOT_USAGE_ENABLED)) { 2373 error = -EINVAL; 2374 goto out_fmt; 2375 } 2376 if (sb_has_quota_loaded(sb, type)) { 2377 error = -EBUSY; 2378 goto out_fmt; 2379 } 2380 2381 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2382 /* As we bypass the pagecache we must now flush all the 2383 * dirty data and invalidate caches so that kernel sees 2384 * changes from userspace. It is not enough to just flush 2385 * the quota file since if blocksize < pagesize, invalidation 2386 * of the cache could fail because of other unrelated dirty 2387 * data */ 2388 sync_filesystem(sb); 2389 invalidate_bdev(sb->s_bdev); 2390 } 2391 2392 error = -EINVAL; 2393 if (!fmt->qf_ops->check_quota_file(sb, type)) 2394 goto out_fmt; 2395 2396 dqopt->ops[type] = fmt->qf_ops; 2397 dqopt->info[type].dqi_format = fmt; 2398 dqopt->info[type].dqi_fmt_id = format_id; 2399 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2400 error = dqopt->ops[type]->read_file_info(sb, type); 2401 if (error < 0) 2402 goto out_fmt; 2403 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) { 2404 spin_lock(&dq_data_lock); 2405 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2406 spin_unlock(&dq_data_lock); 2407 } 2408 spin_lock(&dq_state_lock); 2409 dqopt->flags |= dquot_state_flag(flags, type); 2410 spin_unlock(&dq_state_lock); 2411 2412 error = add_dquot_ref(sb, type); 2413 if (error) 2414 dquot_disable(sb, type, flags); 2415 2416 return error; 2417 out_fmt: 2418 put_quota_format(fmt); 2419 2420 return error; 2421 } 2422 EXPORT_SYMBOL(dquot_load_quota_sb); 2423 2424 /* 2425 * More powerful function for turning on quotas on given quota inode allowing 2426 * setting of individual quota flags 2427 */ 2428 int dquot_load_quota_inode(struct inode *inode, int type, int format_id, 2429 unsigned int flags) 2430 { 2431 int err; 2432 2433 err = vfs_setup_quota_inode(inode, type); 2434 if (err < 0) 2435 return err; 2436 err = dquot_load_quota_sb(inode->i_sb, type, format_id, flags); 2437 if (err < 0) 2438 vfs_cleanup_quota_inode(inode->i_sb, type); 2439 return err; 2440 } 2441 EXPORT_SYMBOL(dquot_load_quota_inode); 2442 2443 /* Reenable quotas on remount RW */ 2444 int dquot_resume(struct super_block *sb, int type) 2445 { 2446 struct quota_info *dqopt = sb_dqopt(sb); 2447 int ret = 0, cnt; 2448 unsigned int flags; 2449 2450 /* s_umount should be held in exclusive mode */ 2451 if (WARN_ON_ONCE(down_read_trylock(&sb->s_umount))) 2452 up_read(&sb->s_umount); 2453 2454 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2455 if (type != -1 && cnt != type) 2456 continue; 2457 if (!sb_has_quota_suspended(sb, cnt)) 2458 continue; 2459 2460 spin_lock(&dq_state_lock); 2461 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2462 DQUOT_LIMITS_ENABLED, 2463 cnt); 2464 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2465 spin_unlock(&dq_state_lock); 2466 2467 flags = dquot_generic_flag(flags, cnt); 2468 ret = dquot_load_quota_sb(sb, cnt, dqopt->info[cnt].dqi_fmt_id, 2469 flags); 2470 if (ret < 0) 2471 vfs_cleanup_quota_inode(sb, cnt); 2472 } 2473 2474 return ret; 2475 } 2476 EXPORT_SYMBOL(dquot_resume); 2477 2478 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2479 const struct path *path) 2480 { 2481 int error = security_quota_on(path->dentry); 2482 if (error) 2483 return error; 2484 /* Quota file not on the same filesystem? */ 2485 if (path->dentry->d_sb != sb) 2486 error = -EXDEV; 2487 else 2488 error = dquot_load_quota_inode(d_inode(path->dentry), type, 2489 format_id, DQUOT_USAGE_ENABLED | 2490 DQUOT_LIMITS_ENABLED); 2491 return error; 2492 } 2493 EXPORT_SYMBOL(dquot_quota_on); 2494 2495 /* 2496 * This function is used when filesystem needs to initialize quotas 2497 * during mount time. 2498 */ 2499 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2500 int format_id, int type) 2501 { 2502 struct dentry *dentry; 2503 int error; 2504 2505 dentry = lookup_positive_unlocked(qf_name, sb->s_root, strlen(qf_name)); 2506 if (IS_ERR(dentry)) 2507 return PTR_ERR(dentry); 2508 2509 error = security_quota_on(dentry); 2510 if (!error) 2511 error = dquot_load_quota_inode(d_inode(dentry), type, format_id, 2512 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2513 2514 dput(dentry); 2515 return error; 2516 } 2517 EXPORT_SYMBOL(dquot_quota_on_mount); 2518 2519 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2520 { 2521 int ret; 2522 int type; 2523 struct quota_info *dqopt = sb_dqopt(sb); 2524 2525 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2526 return -ENOSYS; 2527 /* Accounting cannot be turned on while fs is mounted */ 2528 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2529 if (!flags) 2530 return -EINVAL; 2531 for (type = 0; type < MAXQUOTAS; type++) { 2532 if (!(flags & qtype_enforce_flag(type))) 2533 continue; 2534 /* Can't enforce without accounting */ 2535 if (!sb_has_quota_usage_enabled(sb, type)) { 2536 ret = -EINVAL; 2537 goto out_err; 2538 } 2539 if (sb_has_quota_limits_enabled(sb, type)) { 2540 ret = -EBUSY; 2541 goto out_err; 2542 } 2543 spin_lock(&dq_state_lock); 2544 dqopt->flags |= dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2545 spin_unlock(&dq_state_lock); 2546 } 2547 return 0; 2548 out_err: 2549 /* Backout enforcement enablement we already did */ 2550 for (type--; type >= 0; type--) { 2551 if (flags & qtype_enforce_flag(type)) 2552 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2553 } 2554 /* Error code translation for better compatibility with XFS */ 2555 if (ret == -EBUSY) 2556 ret = -EEXIST; 2557 return ret; 2558 } 2559 2560 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2561 { 2562 int ret; 2563 int type; 2564 struct quota_info *dqopt = sb_dqopt(sb); 2565 2566 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2567 return -ENOSYS; 2568 /* 2569 * We don't support turning off accounting via quotactl. In principle 2570 * quota infrastructure can do this but filesystems don't expect 2571 * userspace to be able to do it. 2572 */ 2573 if (flags & 2574 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2575 return -EOPNOTSUPP; 2576 2577 /* Filter out limits not enabled */ 2578 for (type = 0; type < MAXQUOTAS; type++) 2579 if (!sb_has_quota_limits_enabled(sb, type)) 2580 flags &= ~qtype_enforce_flag(type); 2581 /* Nothing left? */ 2582 if (!flags) 2583 return -EEXIST; 2584 for (type = 0; type < MAXQUOTAS; type++) { 2585 if (flags & qtype_enforce_flag(type)) { 2586 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2587 if (ret < 0) 2588 goto out_err; 2589 } 2590 } 2591 return 0; 2592 out_err: 2593 /* Backout enforcement disabling we already did */ 2594 for (type--; type >= 0; type--) { 2595 if (flags & qtype_enforce_flag(type)) { 2596 spin_lock(&dq_state_lock); 2597 dqopt->flags |= 2598 dquot_state_flag(DQUOT_LIMITS_ENABLED, type); 2599 spin_unlock(&dq_state_lock); 2600 } 2601 } 2602 return ret; 2603 } 2604 2605 /* Generic routine for getting common part of quota structure */ 2606 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2607 { 2608 struct mem_dqblk *dm = &dquot->dq_dqb; 2609 2610 memset(di, 0, sizeof(*di)); 2611 spin_lock(&dquot->dq_dqb_lock); 2612 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2613 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2614 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2615 di->d_ino_softlimit = dm->dqb_isoftlimit; 2616 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2617 di->d_ino_count = dm->dqb_curinodes; 2618 di->d_spc_timer = dm->dqb_btime; 2619 di->d_ino_timer = dm->dqb_itime; 2620 spin_unlock(&dquot->dq_dqb_lock); 2621 } 2622 2623 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2624 struct qc_dqblk *di) 2625 { 2626 struct dquot *dquot; 2627 2628 dquot = dqget(sb, qid); 2629 if (IS_ERR(dquot)) 2630 return PTR_ERR(dquot); 2631 do_get_dqblk(dquot, di); 2632 dqput(dquot); 2633 2634 return 0; 2635 } 2636 EXPORT_SYMBOL(dquot_get_dqblk); 2637 2638 int dquot_get_next_dqblk(struct super_block *sb, struct kqid *qid, 2639 struct qc_dqblk *di) 2640 { 2641 struct dquot *dquot; 2642 int err; 2643 2644 if (!sb->dq_op->get_next_id) 2645 return -ENOSYS; 2646 err = sb->dq_op->get_next_id(sb, qid); 2647 if (err < 0) 2648 return err; 2649 dquot = dqget(sb, *qid); 2650 if (IS_ERR(dquot)) 2651 return PTR_ERR(dquot); 2652 do_get_dqblk(dquot, di); 2653 dqput(dquot); 2654 2655 return 0; 2656 } 2657 EXPORT_SYMBOL(dquot_get_next_dqblk); 2658 2659 #define VFS_QC_MASK \ 2660 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2661 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2662 QC_SPC_TIMER | QC_INO_TIMER) 2663 2664 /* Generic routine for setting common part of quota structure */ 2665 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2666 { 2667 struct mem_dqblk *dm = &dquot->dq_dqb; 2668 int check_blim = 0, check_ilim = 0; 2669 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2670 2671 if (di->d_fieldmask & ~VFS_QC_MASK) 2672 return -EINVAL; 2673 2674 if (((di->d_fieldmask & QC_SPC_SOFT) && 2675 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2676 ((di->d_fieldmask & QC_SPC_HARD) && 2677 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2678 ((di->d_fieldmask & QC_INO_SOFT) && 2679 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2680 ((di->d_fieldmask & QC_INO_HARD) && 2681 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2682 return -ERANGE; 2683 2684 spin_lock(&dquot->dq_dqb_lock); 2685 if (di->d_fieldmask & QC_SPACE) { 2686 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2687 check_blim = 1; 2688 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2689 } 2690 2691 if (di->d_fieldmask & QC_SPC_SOFT) 2692 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2693 if (di->d_fieldmask & QC_SPC_HARD) 2694 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2695 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2696 check_blim = 1; 2697 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2698 } 2699 2700 if (di->d_fieldmask & QC_INO_COUNT) { 2701 dm->dqb_curinodes = di->d_ino_count; 2702 check_ilim = 1; 2703 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2704 } 2705 2706 if (di->d_fieldmask & QC_INO_SOFT) 2707 dm->dqb_isoftlimit = di->d_ino_softlimit; 2708 if (di->d_fieldmask & QC_INO_HARD) 2709 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2710 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2711 check_ilim = 1; 2712 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2713 } 2714 2715 if (di->d_fieldmask & QC_SPC_TIMER) { 2716 dm->dqb_btime = di->d_spc_timer; 2717 check_blim = 1; 2718 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2719 } 2720 2721 if (di->d_fieldmask & QC_INO_TIMER) { 2722 dm->dqb_itime = di->d_ino_timer; 2723 check_ilim = 1; 2724 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2725 } 2726 2727 if (check_blim) { 2728 if (!dm->dqb_bsoftlimit || 2729 dm->dqb_curspace + dm->dqb_rsvspace <= dm->dqb_bsoftlimit) { 2730 dm->dqb_btime = 0; 2731 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2732 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2733 /* Set grace only if user hasn't provided his own... */ 2734 dm->dqb_btime = ktime_get_real_seconds() + dqi->dqi_bgrace; 2735 } 2736 if (check_ilim) { 2737 if (!dm->dqb_isoftlimit || 2738 dm->dqb_curinodes <= dm->dqb_isoftlimit) { 2739 dm->dqb_itime = 0; 2740 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2741 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2742 /* Set grace only if user hasn't provided his own... */ 2743 dm->dqb_itime = ktime_get_real_seconds() + dqi->dqi_igrace; 2744 } 2745 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2746 dm->dqb_isoftlimit) 2747 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2748 else 2749 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2750 spin_unlock(&dquot->dq_dqb_lock); 2751 mark_dquot_dirty(dquot); 2752 2753 return 0; 2754 } 2755 2756 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2757 struct qc_dqblk *di) 2758 { 2759 struct dquot *dquot; 2760 int rc; 2761 2762 dquot = dqget(sb, qid); 2763 if (IS_ERR(dquot)) { 2764 rc = PTR_ERR(dquot); 2765 goto out; 2766 } 2767 rc = do_set_dqblk(dquot, di); 2768 dqput(dquot); 2769 out: 2770 return rc; 2771 } 2772 EXPORT_SYMBOL(dquot_set_dqblk); 2773 2774 /* Generic routine for getting common part of quota file information */ 2775 int dquot_get_state(struct super_block *sb, struct qc_state *state) 2776 { 2777 struct mem_dqinfo *mi; 2778 struct qc_type_state *tstate; 2779 struct quota_info *dqopt = sb_dqopt(sb); 2780 int type; 2781 2782 memset(state, 0, sizeof(*state)); 2783 for (type = 0; type < MAXQUOTAS; type++) { 2784 if (!sb_has_quota_active(sb, type)) 2785 continue; 2786 tstate = state->s_state + type; 2787 mi = sb_dqopt(sb)->info + type; 2788 tstate->flags = QCI_ACCT_ENABLED; 2789 spin_lock(&dq_data_lock); 2790 if (mi->dqi_flags & DQF_SYS_FILE) 2791 tstate->flags |= QCI_SYSFILE; 2792 if (mi->dqi_flags & DQF_ROOT_SQUASH) 2793 tstate->flags |= QCI_ROOT_SQUASH; 2794 if (sb_has_quota_limits_enabled(sb, type)) 2795 tstate->flags |= QCI_LIMITS_ENFORCED; 2796 tstate->spc_timelimit = mi->dqi_bgrace; 2797 tstate->ino_timelimit = mi->dqi_igrace; 2798 if (dqopt->files[type]) { 2799 tstate->ino = dqopt->files[type]->i_ino; 2800 tstate->blocks = dqopt->files[type]->i_blocks; 2801 } 2802 tstate->nextents = 1; /* We don't know... */ 2803 spin_unlock(&dq_data_lock); 2804 } 2805 return 0; 2806 } 2807 EXPORT_SYMBOL(dquot_get_state); 2808 2809 /* Generic routine for setting common part of quota file information */ 2810 int dquot_set_dqinfo(struct super_block *sb, int type, struct qc_info *ii) 2811 { 2812 struct mem_dqinfo *mi; 2813 int err = 0; 2814 2815 if ((ii->i_fieldmask & QC_WARNS_MASK) || 2816 (ii->i_fieldmask & QC_RT_SPC_TIMER)) 2817 return -EINVAL; 2818 if (!sb_has_quota_active(sb, type)) 2819 return -ESRCH; 2820 mi = sb_dqopt(sb)->info + type; 2821 if (ii->i_fieldmask & QC_FLAGS) { 2822 if ((ii->i_flags & QCI_ROOT_SQUASH && 2823 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) 2824 return -EINVAL; 2825 } 2826 spin_lock(&dq_data_lock); 2827 if (ii->i_fieldmask & QC_SPC_TIMER) 2828 mi->dqi_bgrace = ii->i_spc_timelimit; 2829 if (ii->i_fieldmask & QC_INO_TIMER) 2830 mi->dqi_igrace = ii->i_ino_timelimit; 2831 if (ii->i_fieldmask & QC_FLAGS) { 2832 if (ii->i_flags & QCI_ROOT_SQUASH) 2833 mi->dqi_flags |= DQF_ROOT_SQUASH; 2834 else 2835 mi->dqi_flags &= ~DQF_ROOT_SQUASH; 2836 } 2837 spin_unlock(&dq_data_lock); 2838 mark_info_dirty(sb, type); 2839 /* Force write to disk */ 2840 sb->dq_op->write_info(sb, type); 2841 return err; 2842 } 2843 EXPORT_SYMBOL(dquot_set_dqinfo); 2844 2845 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2846 .quota_enable = dquot_quota_enable, 2847 .quota_disable = dquot_quota_disable, 2848 .quota_sync = dquot_quota_sync, 2849 .get_state = dquot_get_state, 2850 .set_info = dquot_set_dqinfo, 2851 .get_dqblk = dquot_get_dqblk, 2852 .get_nextdqblk = dquot_get_next_dqblk, 2853 .set_dqblk = dquot_set_dqblk 2854 }; 2855 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2856 2857 static int do_proc_dqstats(struct ctl_table *table, int write, 2858 void *buffer, size_t *lenp, loff_t *ppos) 2859 { 2860 unsigned int type = (unsigned long *)table->data - dqstats.stat; 2861 s64 value = percpu_counter_sum(&dqstats.counter[type]); 2862 2863 /* Filter negative values for non-monotonic counters */ 2864 if (value < 0 && (type == DQST_ALLOC_DQUOTS || 2865 type == DQST_FREE_DQUOTS)) 2866 value = 0; 2867 2868 /* Update global table */ 2869 dqstats.stat[type] = value; 2870 return proc_doulongvec_minmax(table, write, buffer, lenp, ppos); 2871 } 2872 2873 static struct ctl_table fs_dqstats_table[] = { 2874 { 2875 .procname = "lookups", 2876 .data = &dqstats.stat[DQST_LOOKUPS], 2877 .maxlen = sizeof(unsigned long), 2878 .mode = 0444, 2879 .proc_handler = do_proc_dqstats, 2880 }, 2881 { 2882 .procname = "drops", 2883 .data = &dqstats.stat[DQST_DROPS], 2884 .maxlen = sizeof(unsigned long), 2885 .mode = 0444, 2886 .proc_handler = do_proc_dqstats, 2887 }, 2888 { 2889 .procname = "reads", 2890 .data = &dqstats.stat[DQST_READS], 2891 .maxlen = sizeof(unsigned long), 2892 .mode = 0444, 2893 .proc_handler = do_proc_dqstats, 2894 }, 2895 { 2896 .procname = "writes", 2897 .data = &dqstats.stat[DQST_WRITES], 2898 .maxlen = sizeof(unsigned long), 2899 .mode = 0444, 2900 .proc_handler = do_proc_dqstats, 2901 }, 2902 { 2903 .procname = "cache_hits", 2904 .data = &dqstats.stat[DQST_CACHE_HITS], 2905 .maxlen = sizeof(unsigned long), 2906 .mode = 0444, 2907 .proc_handler = do_proc_dqstats, 2908 }, 2909 { 2910 .procname = "allocated_dquots", 2911 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2912 .maxlen = sizeof(unsigned long), 2913 .mode = 0444, 2914 .proc_handler = do_proc_dqstats, 2915 }, 2916 { 2917 .procname = "free_dquots", 2918 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2919 .maxlen = sizeof(unsigned long), 2920 .mode = 0444, 2921 .proc_handler = do_proc_dqstats, 2922 }, 2923 { 2924 .procname = "syncs", 2925 .data = &dqstats.stat[DQST_SYNCS], 2926 .maxlen = sizeof(unsigned long), 2927 .mode = 0444, 2928 .proc_handler = do_proc_dqstats, 2929 }, 2930 #ifdef CONFIG_PRINT_QUOTA_WARNING 2931 { 2932 .procname = "warnings", 2933 .data = &flag_print_warnings, 2934 .maxlen = sizeof(int), 2935 .mode = 0644, 2936 .proc_handler = proc_dointvec, 2937 }, 2938 #endif 2939 { }, 2940 }; 2941 2942 static struct ctl_table fs_table[] = { 2943 { 2944 .procname = "quota", 2945 .mode = 0555, 2946 .child = fs_dqstats_table, 2947 }, 2948 { }, 2949 }; 2950 2951 static struct ctl_table sys_table[] = { 2952 { 2953 .procname = "fs", 2954 .mode = 0555, 2955 .child = fs_table, 2956 }, 2957 { }, 2958 }; 2959 2960 static int __init dquot_init(void) 2961 { 2962 int i, ret; 2963 unsigned long nr_hash, order; 2964 2965 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2966 2967 register_sysctl_table(sys_table); 2968 2969 dquot_cachep = kmem_cache_create("dquot", 2970 sizeof(struct dquot), sizeof(unsigned long) * 4, 2971 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2972 SLAB_MEM_SPREAD|SLAB_PANIC), 2973 NULL); 2974 2975 order = 0; 2976 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_KERNEL, order); 2977 if (!dquot_hash) 2978 panic("Cannot create dquot hash table"); 2979 2980 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2981 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2982 if (ret) 2983 panic("Cannot create dquot stat counters"); 2984 } 2985 2986 /* Find power-of-two hlist_heads which can fit into allocation */ 2987 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2988 dq_hash_bits = ilog2(nr_hash); 2989 2990 nr_hash = 1UL << dq_hash_bits; 2991 dq_hash_mask = nr_hash - 1; 2992 for (i = 0; i < nr_hash; i++) 2993 INIT_HLIST_HEAD(dquot_hash + i); 2994 2995 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2996 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2997 2998 if (register_shrinker(&dqcache_shrinker)) 2999 panic("Cannot register dquot shrinker"); 3000 3001 return 0; 3002 } 3003 fs_initcall(dquot_init); 3004