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