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 <asm/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 * Any operation working on dquots via inode pointers must hold dqptr_sem. If 100 * operation is just reading pointers from inode (or not using them at all) the 101 * read lock is enough. If pointers are altered function must hold write lock. 102 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 103 * inode is a quota file). Functions adding pointers from inode to dquots have 104 * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they 105 * have to do all pointer modifications before dropping dqptr_sem. This makes 106 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 107 * then drops all pointers to dquots from an inode. 108 * 109 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced 110 * from inodes (dquot_alloc_space() and such don't check the dq_lock). 111 * Currently dquot is locked only when it is being read to memory (or space for 112 * it is being allocated) on the first dqget() and when it is being released on 113 * the last dqput(). The allocation and release oparations are serialized by 114 * the dq_lock and by checking the use count in dquot_release(). Write 115 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock 116 * spinlock to internal buffers before writing. 117 * 118 * Lock ordering (including related VFS locks) is the following: 119 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > 120 * dqio_mutex 121 * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem > 122 * dqptr_sem. But filesystem has to count with the fact that functions such as 123 * dquot_alloc_space() acquire dqptr_sem and they usually have to be called 124 * from inside a transaction to keep filesystem consistency after a crash. Also 125 * filesystems usually want to do some IO on dquot from ->mark_dirty which is 126 * called with dqptr_sem held. 127 * i_mutex on quota files is special (it's below dqio_mutex) 128 */ 129 130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 131 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 132 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 133 EXPORT_SYMBOL(dq_data_lock); 134 135 void __quota_error(struct super_block *sb, const char *func, 136 const char *fmt, ...) 137 { 138 if (printk_ratelimit()) { 139 va_list args; 140 struct va_format vaf; 141 142 va_start(args, fmt); 143 144 vaf.fmt = fmt; 145 vaf.va = &args; 146 147 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 148 sb->s_id, func, &vaf); 149 150 va_end(args); 151 } 152 } 153 EXPORT_SYMBOL(__quota_error); 154 155 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 156 static char *quotatypes[] = INITQFNAMES; 157 #endif 158 static struct quota_format_type *quota_formats; /* List of registered formats */ 159 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 160 161 /* SLAB cache for dquot structures */ 162 static struct kmem_cache *dquot_cachep; 163 164 int register_quota_format(struct quota_format_type *fmt) 165 { 166 spin_lock(&dq_list_lock); 167 fmt->qf_next = quota_formats; 168 quota_formats = fmt; 169 spin_unlock(&dq_list_lock); 170 return 0; 171 } 172 EXPORT_SYMBOL(register_quota_format); 173 174 void unregister_quota_format(struct quota_format_type *fmt) 175 { 176 struct quota_format_type **actqf; 177 178 spin_lock(&dq_list_lock); 179 for (actqf = "a_formats; *actqf && *actqf != fmt; 180 actqf = &(*actqf)->qf_next) 181 ; 182 if (*actqf) 183 *actqf = (*actqf)->qf_next; 184 spin_unlock(&dq_list_lock); 185 } 186 EXPORT_SYMBOL(unregister_quota_format); 187 188 static struct quota_format_type *find_quota_format(int id) 189 { 190 struct quota_format_type *actqf; 191 192 spin_lock(&dq_list_lock); 193 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 194 actqf = actqf->qf_next) 195 ; 196 if (!actqf || !try_module_get(actqf->qf_owner)) { 197 int qm; 198 199 spin_unlock(&dq_list_lock); 200 201 for (qm = 0; module_names[qm].qm_fmt_id && 202 module_names[qm].qm_fmt_id != id; qm++) 203 ; 204 if (!module_names[qm].qm_fmt_id || 205 request_module(module_names[qm].qm_mod_name)) 206 return NULL; 207 208 spin_lock(&dq_list_lock); 209 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 210 actqf = actqf->qf_next) 211 ; 212 if (actqf && !try_module_get(actqf->qf_owner)) 213 actqf = NULL; 214 } 215 spin_unlock(&dq_list_lock); 216 return actqf; 217 } 218 219 static void put_quota_format(struct quota_format_type *fmt) 220 { 221 module_put(fmt->qf_owner); 222 } 223 224 /* 225 * Dquot List Management: 226 * The quota code uses three lists for dquot management: the inuse_list, 227 * free_dquots, and dquot_hash[] array. A single dquot structure may be 228 * on all three lists, depending on its current state. 229 * 230 * All dquots are placed to the end of inuse_list when first created, and this 231 * list is used for invalidate operation, which must look at every dquot. 232 * 233 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 234 * and this list is searched whenever we need an available dquot. Dquots are 235 * removed from the list as soon as they are used again, and 236 * dqstats.free_dquots gives the number of dquots on the list. When 237 * dquot is invalidated it's completely released from memory. 238 * 239 * Dquots with a specific identity (device, type and id) are placed on 240 * one of the dquot_hash[] hash chains. The provides an efficient search 241 * mechanism to locate a specific dquot. 242 */ 243 244 static LIST_HEAD(inuse_list); 245 static LIST_HEAD(free_dquots); 246 static unsigned int dq_hash_bits, dq_hash_mask; 247 static struct hlist_head *dquot_hash; 248 249 struct dqstats dqstats; 250 EXPORT_SYMBOL(dqstats); 251 252 static qsize_t inode_get_rsv_space(struct inode *inode); 253 static void __dquot_initialize(struct inode *inode, int type); 254 255 static inline unsigned int 256 hashfn(const struct super_block *sb, unsigned int id, int type) 257 { 258 unsigned long tmp; 259 260 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 261 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 262 } 263 264 /* 265 * Following list functions expect dq_list_lock to be held 266 */ 267 static inline void insert_dquot_hash(struct dquot *dquot) 268 { 269 struct hlist_head *head; 270 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 271 hlist_add_head(&dquot->dq_hash, head); 272 } 273 274 static inline void remove_dquot_hash(struct dquot *dquot) 275 { 276 hlist_del_init(&dquot->dq_hash); 277 } 278 279 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 280 unsigned int id, int type) 281 { 282 struct hlist_node *node; 283 struct dquot *dquot; 284 285 hlist_for_each (node, dquot_hash+hashent) { 286 dquot = hlist_entry(node, struct dquot, dq_hash); 287 if (dquot->dq_sb == sb && dquot->dq_id == id && 288 dquot->dq_type == type) 289 return dquot; 290 } 291 return NULL; 292 } 293 294 /* Add a dquot to the tail of the free list */ 295 static inline void put_dquot_last(struct dquot *dquot) 296 { 297 list_add_tail(&dquot->dq_free, &free_dquots); 298 dqstats_inc(DQST_FREE_DQUOTS); 299 } 300 301 static inline void remove_free_dquot(struct dquot *dquot) 302 { 303 if (list_empty(&dquot->dq_free)) 304 return; 305 list_del_init(&dquot->dq_free); 306 dqstats_dec(DQST_FREE_DQUOTS); 307 } 308 309 static inline void put_inuse(struct dquot *dquot) 310 { 311 /* We add to the back of inuse list so we don't have to restart 312 * when traversing this list and we block */ 313 list_add_tail(&dquot->dq_inuse, &inuse_list); 314 dqstats_inc(DQST_ALLOC_DQUOTS); 315 } 316 317 static inline void remove_inuse(struct dquot *dquot) 318 { 319 dqstats_dec(DQST_ALLOC_DQUOTS); 320 list_del(&dquot->dq_inuse); 321 } 322 /* 323 * End of list functions needing dq_list_lock 324 */ 325 326 static void wait_on_dquot(struct dquot *dquot) 327 { 328 mutex_lock(&dquot->dq_lock); 329 mutex_unlock(&dquot->dq_lock); 330 } 331 332 static inline int dquot_dirty(struct dquot *dquot) 333 { 334 return test_bit(DQ_MOD_B, &dquot->dq_flags); 335 } 336 337 static inline int mark_dquot_dirty(struct dquot *dquot) 338 { 339 return dquot->dq_sb->dq_op->mark_dirty(dquot); 340 } 341 342 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 343 int dquot_mark_dquot_dirty(struct dquot *dquot) 344 { 345 int ret = 1; 346 347 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 348 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 349 return 1; 350 351 spin_lock(&dq_list_lock); 352 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 353 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 354 info[dquot->dq_type].dqi_dirty_list); 355 ret = 0; 356 } 357 spin_unlock(&dq_list_lock); 358 return ret; 359 } 360 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 361 362 /* Dirtify all the dquots - this can block when journalling */ 363 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 364 { 365 int ret, err, cnt; 366 367 ret = err = 0; 368 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 369 if (dquot[cnt]) 370 /* Even in case of error we have to continue */ 371 ret = mark_dquot_dirty(dquot[cnt]); 372 if (!err) 373 err = ret; 374 } 375 return err; 376 } 377 378 static inline void dqput_all(struct dquot **dquot) 379 { 380 unsigned int cnt; 381 382 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 383 dqput(dquot[cnt]); 384 } 385 386 /* This function needs dq_list_lock */ 387 static inline int clear_dquot_dirty(struct dquot *dquot) 388 { 389 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 390 return 0; 391 list_del_init(&dquot->dq_dirty); 392 return 1; 393 } 394 395 void mark_info_dirty(struct super_block *sb, int type) 396 { 397 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 398 } 399 EXPORT_SYMBOL(mark_info_dirty); 400 401 /* 402 * Read dquot from disk and alloc space for it 403 */ 404 405 int dquot_acquire(struct dquot *dquot) 406 { 407 int ret = 0, ret2 = 0; 408 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 409 410 mutex_lock(&dquot->dq_lock); 411 mutex_lock(&dqopt->dqio_mutex); 412 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 413 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 414 if (ret < 0) 415 goto out_iolock; 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_type]->commit_dqblk(dquot); 420 /* Write the info if needed */ 421 if (info_dirty(&dqopt->info[dquot->dq_type])) { 422 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 423 dquot->dq_sb, dquot->dq_type); 424 } 425 if (ret < 0) 426 goto out_iolock; 427 if (ret2 < 0) { 428 ret = ret2; 429 goto out_iolock; 430 } 431 } 432 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 433 out_iolock: 434 mutex_unlock(&dqopt->dqio_mutex); 435 mutex_unlock(&dquot->dq_lock); 436 return ret; 437 } 438 EXPORT_SYMBOL(dquot_acquire); 439 440 /* 441 * Write dquot to disk 442 */ 443 int dquot_commit(struct dquot *dquot) 444 { 445 int ret = 0; 446 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 447 448 mutex_lock(&dqopt->dqio_mutex); 449 spin_lock(&dq_list_lock); 450 if (!clear_dquot_dirty(dquot)) { 451 spin_unlock(&dq_list_lock); 452 goto out_sem; 453 } 454 spin_unlock(&dq_list_lock); 455 /* Inactive dquot can be only if there was error during read/init 456 * => we have better not writing it */ 457 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 458 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 459 else 460 ret = -EIO; 461 out_sem: 462 mutex_unlock(&dqopt->dqio_mutex); 463 return ret; 464 } 465 EXPORT_SYMBOL(dquot_commit); 466 467 /* 468 * Release dquot 469 */ 470 int dquot_release(struct dquot *dquot) 471 { 472 int ret = 0, ret2 = 0; 473 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 474 475 mutex_lock(&dquot->dq_lock); 476 /* Check whether we are not racing with some other dqget() */ 477 if (atomic_read(&dquot->dq_count) > 1) 478 goto out_dqlock; 479 mutex_lock(&dqopt->dqio_mutex); 480 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 481 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 482 /* Write the info */ 483 if (info_dirty(&dqopt->info[dquot->dq_type])) { 484 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 485 dquot->dq_sb, dquot->dq_type); 486 } 487 if (ret >= 0) 488 ret = ret2; 489 } 490 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 491 mutex_unlock(&dqopt->dqio_mutex); 492 out_dqlock: 493 mutex_unlock(&dquot->dq_lock); 494 return ret; 495 } 496 EXPORT_SYMBOL(dquot_release); 497 498 void dquot_destroy(struct dquot *dquot) 499 { 500 kmem_cache_free(dquot_cachep, dquot); 501 } 502 EXPORT_SYMBOL(dquot_destroy); 503 504 static inline void do_destroy_dquot(struct dquot *dquot) 505 { 506 dquot->dq_sb->dq_op->destroy_dquot(dquot); 507 } 508 509 /* Invalidate all dquots on the list. Note that this function is called after 510 * quota is disabled and pointers from inodes removed so there cannot be new 511 * quota users. There can still be some users of quotas due to inodes being 512 * just deleted or pruned by prune_icache() (those are not attached to any 513 * list) or parallel quotactl call. We have to wait for such users. 514 */ 515 static void invalidate_dquots(struct super_block *sb, int type) 516 { 517 struct dquot *dquot, *tmp; 518 519 restart: 520 spin_lock(&dq_list_lock); 521 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 522 if (dquot->dq_sb != sb) 523 continue; 524 if (dquot->dq_type != type) 525 continue; 526 /* Wait for dquot users */ 527 if (atomic_read(&dquot->dq_count)) { 528 DEFINE_WAIT(wait); 529 530 atomic_inc(&dquot->dq_count); 531 prepare_to_wait(&dquot->dq_wait_unused, &wait, 532 TASK_UNINTERRUPTIBLE); 533 spin_unlock(&dq_list_lock); 534 /* Once dqput() wakes us up, we know it's time to free 535 * the dquot. 536 * IMPORTANT: we rely on the fact that there is always 537 * at most one process waiting for dquot to free. 538 * Otherwise dq_count would be > 1 and we would never 539 * wake up. 540 */ 541 if (atomic_read(&dquot->dq_count) > 1) 542 schedule(); 543 finish_wait(&dquot->dq_wait_unused, &wait); 544 dqput(dquot); 545 /* At this moment dquot() need not exist (it could be 546 * reclaimed by prune_dqcache(). Hence we must 547 * restart. */ 548 goto restart; 549 } 550 /* 551 * Quota now has no users and it has been written on last 552 * dqput() 553 */ 554 remove_dquot_hash(dquot); 555 remove_free_dquot(dquot); 556 remove_inuse(dquot); 557 do_destroy_dquot(dquot); 558 } 559 spin_unlock(&dq_list_lock); 560 } 561 562 /* Call callback for every active dquot on given filesystem */ 563 int dquot_scan_active(struct super_block *sb, 564 int (*fn)(struct dquot *dquot, unsigned long priv), 565 unsigned long priv) 566 { 567 struct dquot *dquot, *old_dquot = NULL; 568 int ret = 0; 569 570 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 571 spin_lock(&dq_list_lock); 572 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 573 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 574 continue; 575 if (dquot->dq_sb != sb) 576 continue; 577 /* Now we have active dquot so we can just increase use count */ 578 atomic_inc(&dquot->dq_count); 579 spin_unlock(&dq_list_lock); 580 dqstats_inc(DQST_LOOKUPS); 581 dqput(old_dquot); 582 old_dquot = dquot; 583 ret = fn(dquot, priv); 584 if (ret < 0) 585 goto out; 586 spin_lock(&dq_list_lock); 587 /* We are safe to continue now because our dquot could not 588 * be moved out of the inuse list while we hold the reference */ 589 } 590 spin_unlock(&dq_list_lock); 591 out: 592 dqput(old_dquot); 593 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 594 return ret; 595 } 596 EXPORT_SYMBOL(dquot_scan_active); 597 598 int dquot_quota_sync(struct super_block *sb, int type, int wait) 599 { 600 struct list_head *dirty; 601 struct dquot *dquot; 602 struct quota_info *dqopt = sb_dqopt(sb); 603 int cnt; 604 605 mutex_lock(&dqopt->dqonoff_mutex); 606 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 607 if (type != -1 && cnt != type) 608 continue; 609 if (!sb_has_quota_active(sb, cnt)) 610 continue; 611 spin_lock(&dq_list_lock); 612 dirty = &dqopt->info[cnt].dqi_dirty_list; 613 while (!list_empty(dirty)) { 614 dquot = list_first_entry(dirty, struct dquot, 615 dq_dirty); 616 /* Dirty and inactive can be only bad dquot... */ 617 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 618 clear_dquot_dirty(dquot); 619 continue; 620 } 621 /* Now we have active dquot from which someone is 622 * holding reference so we can safely just increase 623 * use count */ 624 atomic_inc(&dquot->dq_count); 625 spin_unlock(&dq_list_lock); 626 dqstats_inc(DQST_LOOKUPS); 627 sb->dq_op->write_dquot(dquot); 628 dqput(dquot); 629 spin_lock(&dq_list_lock); 630 } 631 spin_unlock(&dq_list_lock); 632 } 633 634 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 635 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 636 && info_dirty(&dqopt->info[cnt])) 637 sb->dq_op->write_info(sb, cnt); 638 dqstats_inc(DQST_SYNCS); 639 mutex_unlock(&dqopt->dqonoff_mutex); 640 641 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)) 642 return 0; 643 644 /* This is not very clever (and fast) but currently I don't know about 645 * any other simple way of getting quota data to disk and we must get 646 * them there for userspace to be visible... */ 647 if (sb->s_op->sync_fs) 648 sb->s_op->sync_fs(sb, 1); 649 sync_blockdev(sb->s_bdev); 650 651 /* 652 * Now when everything is written we can discard the pagecache so 653 * that userspace sees the changes. 654 */ 655 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 656 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 657 if (type != -1 && cnt != type) 658 continue; 659 if (!sb_has_quota_active(sb, cnt)) 660 continue; 661 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, 662 I_MUTEX_QUOTA); 663 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); 664 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); 665 } 666 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 667 668 return 0; 669 } 670 EXPORT_SYMBOL(dquot_quota_sync); 671 672 /* Free unused dquots from cache */ 673 static void prune_dqcache(int count) 674 { 675 struct list_head *head; 676 struct dquot *dquot; 677 678 head = free_dquots.prev; 679 while (head != &free_dquots && count) { 680 dquot = list_entry(head, struct dquot, dq_free); 681 remove_dquot_hash(dquot); 682 remove_free_dquot(dquot); 683 remove_inuse(dquot); 684 do_destroy_dquot(dquot); 685 count--; 686 head = free_dquots.prev; 687 } 688 } 689 690 /* 691 * This is called from kswapd when we think we need some 692 * more memory 693 */ 694 static int shrink_dqcache_memory(struct shrinker *shrink, 695 struct shrink_control *sc) 696 { 697 int nr = sc->nr_to_scan; 698 699 if (nr) { 700 spin_lock(&dq_list_lock); 701 prune_dqcache(nr); 702 spin_unlock(&dq_list_lock); 703 } 704 return ((unsigned) 705 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]) 706 /100) * sysctl_vfs_cache_pressure; 707 } 708 709 static struct shrinker dqcache_shrinker = { 710 .shrink = shrink_dqcache_memory, 711 .seeks = DEFAULT_SEEKS, 712 }; 713 714 /* 715 * Put reference to dquot 716 * NOTE: If you change this function please check whether dqput_blocks() works right... 717 */ 718 void dqput(struct dquot *dquot) 719 { 720 int ret; 721 722 if (!dquot) 723 return; 724 #ifdef CONFIG_QUOTA_DEBUG 725 if (!atomic_read(&dquot->dq_count)) { 726 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 727 quotatypes[dquot->dq_type], dquot->dq_id); 728 BUG(); 729 } 730 #endif 731 dqstats_inc(DQST_DROPS); 732 we_slept: 733 spin_lock(&dq_list_lock); 734 if (atomic_read(&dquot->dq_count) > 1) { 735 /* We have more than one user... nothing to do */ 736 atomic_dec(&dquot->dq_count); 737 /* Releasing dquot during quotaoff phase? */ 738 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 739 atomic_read(&dquot->dq_count) == 1) 740 wake_up(&dquot->dq_wait_unused); 741 spin_unlock(&dq_list_lock); 742 return; 743 } 744 /* Need to release dquot? */ 745 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 746 spin_unlock(&dq_list_lock); 747 /* Commit dquot before releasing */ 748 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 749 if (ret < 0) { 750 quota_error(dquot->dq_sb, "Can't write quota structure" 751 " (error %d). Quota may get out of sync!", 752 ret); 753 /* 754 * We clear dirty bit anyway, so that we avoid 755 * infinite loop here 756 */ 757 spin_lock(&dq_list_lock); 758 clear_dquot_dirty(dquot); 759 spin_unlock(&dq_list_lock); 760 } 761 goto we_slept; 762 } 763 /* Clear flag in case dquot was inactive (something bad happened) */ 764 clear_dquot_dirty(dquot); 765 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 766 spin_unlock(&dq_list_lock); 767 dquot->dq_sb->dq_op->release_dquot(dquot); 768 goto we_slept; 769 } 770 atomic_dec(&dquot->dq_count); 771 #ifdef CONFIG_QUOTA_DEBUG 772 /* sanity check */ 773 BUG_ON(!list_empty(&dquot->dq_free)); 774 #endif 775 put_dquot_last(dquot); 776 spin_unlock(&dq_list_lock); 777 } 778 EXPORT_SYMBOL(dqput); 779 780 struct dquot *dquot_alloc(struct super_block *sb, int type) 781 { 782 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 783 } 784 EXPORT_SYMBOL(dquot_alloc); 785 786 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 787 { 788 struct dquot *dquot; 789 790 dquot = sb->dq_op->alloc_dquot(sb, type); 791 if(!dquot) 792 return NULL; 793 794 mutex_init(&dquot->dq_lock); 795 INIT_LIST_HEAD(&dquot->dq_free); 796 INIT_LIST_HEAD(&dquot->dq_inuse); 797 INIT_HLIST_NODE(&dquot->dq_hash); 798 INIT_LIST_HEAD(&dquot->dq_dirty); 799 init_waitqueue_head(&dquot->dq_wait_unused); 800 dquot->dq_sb = sb; 801 dquot->dq_type = type; 802 atomic_set(&dquot->dq_count, 1); 803 804 return dquot; 805 } 806 807 /* 808 * Get reference to dquot 809 * 810 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 811 * destroying our dquot by: 812 * a) checking for quota flags under dq_list_lock and 813 * b) getting a reference to dquot before we release dq_list_lock 814 */ 815 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 816 { 817 unsigned int hashent = hashfn(sb, id, type); 818 struct dquot *dquot = NULL, *empty = NULL; 819 820 if (!sb_has_quota_active(sb, type)) 821 return NULL; 822 we_slept: 823 spin_lock(&dq_list_lock); 824 spin_lock(&dq_state_lock); 825 if (!sb_has_quota_active(sb, type)) { 826 spin_unlock(&dq_state_lock); 827 spin_unlock(&dq_list_lock); 828 goto out; 829 } 830 spin_unlock(&dq_state_lock); 831 832 dquot = find_dquot(hashent, sb, id, type); 833 if (!dquot) { 834 if (!empty) { 835 spin_unlock(&dq_list_lock); 836 empty = get_empty_dquot(sb, type); 837 if (!empty) 838 schedule(); /* Try to wait for a moment... */ 839 goto we_slept; 840 } 841 dquot = empty; 842 empty = NULL; 843 dquot->dq_id = id; 844 /* all dquots go on the inuse_list */ 845 put_inuse(dquot); 846 /* hash it first so it can be found */ 847 insert_dquot_hash(dquot); 848 spin_unlock(&dq_list_lock); 849 dqstats_inc(DQST_LOOKUPS); 850 } else { 851 if (!atomic_read(&dquot->dq_count)) 852 remove_free_dquot(dquot); 853 atomic_inc(&dquot->dq_count); 854 spin_unlock(&dq_list_lock); 855 dqstats_inc(DQST_CACHE_HITS); 856 dqstats_inc(DQST_LOOKUPS); 857 } 858 /* Wait for dq_lock - after this we know that either dquot_release() is 859 * already finished or it will be canceled due to dq_count > 1 test */ 860 wait_on_dquot(dquot); 861 /* Read the dquot / allocate space in quota file */ 862 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 863 sb->dq_op->acquire_dquot(dquot) < 0) { 864 dqput(dquot); 865 dquot = NULL; 866 goto out; 867 } 868 #ifdef CONFIG_QUOTA_DEBUG 869 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 870 #endif 871 out: 872 if (empty) 873 do_destroy_dquot(empty); 874 875 return dquot; 876 } 877 EXPORT_SYMBOL(dqget); 878 879 static int dqinit_needed(struct inode *inode, int type) 880 { 881 int cnt; 882 883 if (IS_NOQUOTA(inode)) 884 return 0; 885 if (type != -1) 886 return !inode->i_dquot[type]; 887 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 888 if (!inode->i_dquot[cnt]) 889 return 1; 890 return 0; 891 } 892 893 /* This routine is guarded by dqonoff_mutex mutex */ 894 static void add_dquot_ref(struct super_block *sb, int type) 895 { 896 struct inode *inode, *old_inode = NULL; 897 #ifdef CONFIG_QUOTA_DEBUG 898 int reserved = 0; 899 #endif 900 901 spin_lock(&inode_sb_list_lock); 902 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 903 spin_lock(&inode->i_lock); 904 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 905 !atomic_read(&inode->i_writecount) || 906 !dqinit_needed(inode, type)) { 907 spin_unlock(&inode->i_lock); 908 continue; 909 } 910 #ifdef CONFIG_QUOTA_DEBUG 911 if (unlikely(inode_get_rsv_space(inode) > 0)) 912 reserved = 1; 913 #endif 914 __iget(inode); 915 spin_unlock(&inode->i_lock); 916 spin_unlock(&inode_sb_list_lock); 917 918 iput(old_inode); 919 __dquot_initialize(inode, type); 920 921 /* 922 * We hold a reference to 'inode' so it couldn't have been 923 * removed from s_inodes list while we dropped the 924 * inode_sb_list_lock We cannot iput the inode now as we can be 925 * holding the last reference and we cannot iput it under 926 * inode_sb_list_lock. So we keep the reference and iput it 927 * later. 928 */ 929 old_inode = inode; 930 spin_lock(&inode_sb_list_lock); 931 } 932 spin_unlock(&inode_sb_list_lock); 933 iput(old_inode); 934 935 #ifdef CONFIG_QUOTA_DEBUG 936 if (reserved) { 937 quota_error(sb, "Writes happened before quota was turned on " 938 "thus quota information is probably inconsistent. " 939 "Please run quotacheck(8)"); 940 } 941 #endif 942 } 943 944 /* 945 * Return 0 if dqput() won't block. 946 * (note that 1 doesn't necessarily mean blocking) 947 */ 948 static inline int dqput_blocks(struct dquot *dquot) 949 { 950 if (atomic_read(&dquot->dq_count) <= 1) 951 return 1; 952 return 0; 953 } 954 955 /* 956 * Remove references to dquots from inode and add dquot to list for freeing 957 * if we have the last reference to dquot 958 * We can't race with anybody because we hold dqptr_sem for writing... 959 */ 960 static int remove_inode_dquot_ref(struct inode *inode, int type, 961 struct list_head *tofree_head) 962 { 963 struct dquot *dquot = inode->i_dquot[type]; 964 965 inode->i_dquot[type] = NULL; 966 if (dquot) { 967 if (dqput_blocks(dquot)) { 968 #ifdef CONFIG_QUOTA_DEBUG 969 if (atomic_read(&dquot->dq_count) != 1) 970 quota_error(inode->i_sb, "Adding dquot with " 971 "dq_count %d to dispose list", 972 atomic_read(&dquot->dq_count)); 973 #endif 974 spin_lock(&dq_list_lock); 975 /* As dquot must have currently users it can't be on 976 * the free list... */ 977 list_add(&dquot->dq_free, tofree_head); 978 spin_unlock(&dq_list_lock); 979 return 1; 980 } 981 else 982 dqput(dquot); /* We have guaranteed we won't block */ 983 } 984 return 0; 985 } 986 987 /* 988 * Free list of dquots 989 * Dquots are removed from inodes and no new references can be got so we are 990 * the only ones holding reference 991 */ 992 static void put_dquot_list(struct list_head *tofree_head) 993 { 994 struct list_head *act_head; 995 struct dquot *dquot; 996 997 act_head = tofree_head->next; 998 while (act_head != tofree_head) { 999 dquot = list_entry(act_head, struct dquot, dq_free); 1000 act_head = act_head->next; 1001 /* Remove dquot from the list so we won't have problems... */ 1002 list_del_init(&dquot->dq_free); 1003 dqput(dquot); 1004 } 1005 } 1006 1007 static void remove_dquot_ref(struct super_block *sb, int type, 1008 struct list_head *tofree_head) 1009 { 1010 struct inode *inode; 1011 int reserved = 0; 1012 1013 spin_lock(&inode_sb_list_lock); 1014 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1015 /* 1016 * We have to scan also I_NEW inodes because they can already 1017 * have quota pointer initialized. Luckily, we need to touch 1018 * only quota pointers and these have separate locking 1019 * (dqptr_sem). 1020 */ 1021 if (!IS_NOQUOTA(inode)) { 1022 if (unlikely(inode_get_rsv_space(inode) > 0)) 1023 reserved = 1; 1024 remove_inode_dquot_ref(inode, type, tofree_head); 1025 } 1026 } 1027 spin_unlock(&inode_sb_list_lock); 1028 #ifdef CONFIG_QUOTA_DEBUG 1029 if (reserved) { 1030 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1031 " was disabled thus quota information is probably " 1032 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1033 } 1034 #endif 1035 } 1036 1037 /* Gather all references from inodes and drop them */ 1038 static void drop_dquot_ref(struct super_block *sb, int type) 1039 { 1040 LIST_HEAD(tofree_head); 1041 1042 if (sb->dq_op) { 1043 down_write(&sb_dqopt(sb)->dqptr_sem); 1044 remove_dquot_ref(sb, type, &tofree_head); 1045 up_write(&sb_dqopt(sb)->dqptr_sem); 1046 put_dquot_list(&tofree_head); 1047 } 1048 } 1049 1050 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1051 { 1052 dquot->dq_dqb.dqb_curinodes += number; 1053 } 1054 1055 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1056 { 1057 dquot->dq_dqb.dqb_curspace += number; 1058 } 1059 1060 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1061 { 1062 dquot->dq_dqb.dqb_rsvspace += number; 1063 } 1064 1065 /* 1066 * Claim reserved quota space 1067 */ 1068 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1069 { 1070 if (dquot->dq_dqb.dqb_rsvspace < number) { 1071 WARN_ON_ONCE(1); 1072 number = dquot->dq_dqb.dqb_rsvspace; 1073 } 1074 dquot->dq_dqb.dqb_curspace += number; 1075 dquot->dq_dqb.dqb_rsvspace -= number; 1076 } 1077 1078 static inline 1079 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1080 { 1081 if (dquot->dq_dqb.dqb_rsvspace >= number) 1082 dquot->dq_dqb.dqb_rsvspace -= number; 1083 else { 1084 WARN_ON_ONCE(1); 1085 dquot->dq_dqb.dqb_rsvspace = 0; 1086 } 1087 } 1088 1089 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1090 { 1091 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1092 dquot->dq_dqb.dqb_curinodes >= number) 1093 dquot->dq_dqb.dqb_curinodes -= number; 1094 else 1095 dquot->dq_dqb.dqb_curinodes = 0; 1096 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1097 dquot->dq_dqb.dqb_itime = (time_t) 0; 1098 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1099 } 1100 1101 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1102 { 1103 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1104 dquot->dq_dqb.dqb_curspace >= number) 1105 dquot->dq_dqb.dqb_curspace -= number; 1106 else 1107 dquot->dq_dqb.dqb_curspace = 0; 1108 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1109 dquot->dq_dqb.dqb_btime = (time_t) 0; 1110 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1111 } 1112 1113 static int warning_issued(struct dquot *dquot, const int warntype) 1114 { 1115 int flag = (warntype == QUOTA_NL_BHARDWARN || 1116 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1117 ((warntype == QUOTA_NL_IHARDWARN || 1118 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1119 1120 if (!flag) 1121 return 0; 1122 return test_and_set_bit(flag, &dquot->dq_flags); 1123 } 1124 1125 #ifdef CONFIG_PRINT_QUOTA_WARNING 1126 static int flag_print_warnings = 1; 1127 1128 static int need_print_warning(struct dquot *dquot) 1129 { 1130 if (!flag_print_warnings) 1131 return 0; 1132 1133 switch (dquot->dq_type) { 1134 case USRQUOTA: 1135 return current_fsuid() == dquot->dq_id; 1136 case GRPQUOTA: 1137 return in_group_p(dquot->dq_id); 1138 } 1139 return 0; 1140 } 1141 1142 /* Print warning to user which exceeded quota */ 1143 static void print_warning(struct dquot *dquot, const int warntype) 1144 { 1145 char *msg = NULL; 1146 struct tty_struct *tty; 1147 1148 if (warntype == QUOTA_NL_IHARDBELOW || 1149 warntype == QUOTA_NL_ISOFTBELOW || 1150 warntype == QUOTA_NL_BHARDBELOW || 1151 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1152 return; 1153 1154 tty = get_current_tty(); 1155 if (!tty) 1156 return; 1157 tty_write_message(tty, dquot->dq_sb->s_id); 1158 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1159 tty_write_message(tty, ": warning, "); 1160 else 1161 tty_write_message(tty, ": write failed, "); 1162 tty_write_message(tty, quotatypes[dquot->dq_type]); 1163 switch (warntype) { 1164 case QUOTA_NL_IHARDWARN: 1165 msg = " file limit reached.\r\n"; 1166 break; 1167 case QUOTA_NL_ISOFTLONGWARN: 1168 msg = " file quota exceeded too long.\r\n"; 1169 break; 1170 case QUOTA_NL_ISOFTWARN: 1171 msg = " file quota exceeded.\r\n"; 1172 break; 1173 case QUOTA_NL_BHARDWARN: 1174 msg = " block limit reached.\r\n"; 1175 break; 1176 case QUOTA_NL_BSOFTLONGWARN: 1177 msg = " block quota exceeded too long.\r\n"; 1178 break; 1179 case QUOTA_NL_BSOFTWARN: 1180 msg = " block quota exceeded.\r\n"; 1181 break; 1182 } 1183 tty_write_message(tty, msg); 1184 tty_kref_put(tty); 1185 } 1186 #endif 1187 1188 /* 1189 * Write warnings to the console and send warning messages over netlink. 1190 * 1191 * Note that this function can sleep. 1192 */ 1193 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1194 { 1195 struct dquot *dq; 1196 int i; 1197 1198 for (i = 0; i < MAXQUOTAS; i++) { 1199 dq = dquots[i]; 1200 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1201 !warning_issued(dq, warntype[i])) { 1202 #ifdef CONFIG_PRINT_QUOTA_WARNING 1203 print_warning(dq, warntype[i]); 1204 #endif 1205 quota_send_warning(dq->dq_type, dq->dq_id, 1206 dq->dq_sb->s_dev, warntype[i]); 1207 } 1208 } 1209 } 1210 1211 static int ignore_hardlimit(struct dquot *dquot) 1212 { 1213 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1214 1215 return capable(CAP_SYS_RESOURCE) && 1216 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1217 !(info->dqi_flags & V1_DQF_RSQUASH)); 1218 } 1219 1220 /* needs dq_data_lock */ 1221 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1222 { 1223 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1224 1225 *warntype = QUOTA_NL_NOWARN; 1226 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1227 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1228 return 0; 1229 1230 if (dquot->dq_dqb.dqb_ihardlimit && 1231 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1232 !ignore_hardlimit(dquot)) { 1233 *warntype = QUOTA_NL_IHARDWARN; 1234 return -EDQUOT; 1235 } 1236 1237 if (dquot->dq_dqb.dqb_isoftlimit && 1238 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1239 dquot->dq_dqb.dqb_itime && 1240 get_seconds() >= dquot->dq_dqb.dqb_itime && 1241 !ignore_hardlimit(dquot)) { 1242 *warntype = QUOTA_NL_ISOFTLONGWARN; 1243 return -EDQUOT; 1244 } 1245 1246 if (dquot->dq_dqb.dqb_isoftlimit && 1247 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1248 dquot->dq_dqb.dqb_itime == 0) { 1249 *warntype = QUOTA_NL_ISOFTWARN; 1250 dquot->dq_dqb.dqb_itime = get_seconds() + 1251 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1252 } 1253 1254 return 0; 1255 } 1256 1257 /* needs dq_data_lock */ 1258 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1259 { 1260 qsize_t tspace; 1261 struct super_block *sb = dquot->dq_sb; 1262 1263 *warntype = QUOTA_NL_NOWARN; 1264 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1265 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1266 return 0; 1267 1268 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1269 + space; 1270 1271 if (dquot->dq_dqb.dqb_bhardlimit && 1272 tspace > dquot->dq_dqb.dqb_bhardlimit && 1273 !ignore_hardlimit(dquot)) { 1274 if (!prealloc) 1275 *warntype = QUOTA_NL_BHARDWARN; 1276 return -EDQUOT; 1277 } 1278 1279 if (dquot->dq_dqb.dqb_bsoftlimit && 1280 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1281 dquot->dq_dqb.dqb_btime && 1282 get_seconds() >= dquot->dq_dqb.dqb_btime && 1283 !ignore_hardlimit(dquot)) { 1284 if (!prealloc) 1285 *warntype = QUOTA_NL_BSOFTLONGWARN; 1286 return -EDQUOT; 1287 } 1288 1289 if (dquot->dq_dqb.dqb_bsoftlimit && 1290 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1291 dquot->dq_dqb.dqb_btime == 0) { 1292 if (!prealloc) { 1293 *warntype = QUOTA_NL_BSOFTWARN; 1294 dquot->dq_dqb.dqb_btime = get_seconds() + 1295 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1296 } 1297 else 1298 /* 1299 * We don't allow preallocation to exceed softlimit so exceeding will 1300 * be always printed 1301 */ 1302 return -EDQUOT; 1303 } 1304 1305 return 0; 1306 } 1307 1308 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1309 { 1310 qsize_t newinodes; 1311 1312 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1313 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1314 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1315 return QUOTA_NL_NOWARN; 1316 1317 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1318 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1319 return QUOTA_NL_ISOFTBELOW; 1320 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1321 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1322 return QUOTA_NL_IHARDBELOW; 1323 return QUOTA_NL_NOWARN; 1324 } 1325 1326 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1327 { 1328 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1329 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1330 return QUOTA_NL_NOWARN; 1331 1332 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1333 return QUOTA_NL_BSOFTBELOW; 1334 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1335 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1336 return QUOTA_NL_BHARDBELOW; 1337 return QUOTA_NL_NOWARN; 1338 } 1339 1340 static int dquot_active(const struct inode *inode) 1341 { 1342 struct super_block *sb = inode->i_sb; 1343 1344 if (IS_NOQUOTA(inode)) 1345 return 0; 1346 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1347 } 1348 1349 /* 1350 * Initialize quota pointers in inode 1351 * 1352 * We do things in a bit complicated way but by that we avoid calling 1353 * dqget() and thus filesystem callbacks under dqptr_sem. 1354 * 1355 * It is better to call this function outside of any transaction as it 1356 * might need a lot of space in journal for dquot structure allocation. 1357 */ 1358 static void __dquot_initialize(struct inode *inode, int type) 1359 { 1360 unsigned int id = 0; 1361 int cnt; 1362 struct dquot *got[MAXQUOTAS]; 1363 struct super_block *sb = inode->i_sb; 1364 qsize_t rsv; 1365 1366 /* First test before acquiring mutex - solves deadlocks when we 1367 * re-enter the quota code and are already holding the mutex */ 1368 if (!dquot_active(inode)) 1369 return; 1370 1371 /* First get references to structures we might need. */ 1372 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1373 got[cnt] = NULL; 1374 if (type != -1 && cnt != type) 1375 continue; 1376 switch (cnt) { 1377 case USRQUOTA: 1378 id = inode->i_uid; 1379 break; 1380 case GRPQUOTA: 1381 id = inode->i_gid; 1382 break; 1383 } 1384 got[cnt] = dqget(sb, id, cnt); 1385 } 1386 1387 down_write(&sb_dqopt(sb)->dqptr_sem); 1388 if (IS_NOQUOTA(inode)) 1389 goto out_err; 1390 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1391 if (type != -1 && cnt != type) 1392 continue; 1393 /* Avoid races with quotaoff() */ 1394 if (!sb_has_quota_active(sb, cnt)) 1395 continue; 1396 /* We could race with quotaon or dqget() could have failed */ 1397 if (!got[cnt]) 1398 continue; 1399 if (!inode->i_dquot[cnt]) { 1400 inode->i_dquot[cnt] = got[cnt]; 1401 got[cnt] = NULL; 1402 /* 1403 * Make quota reservation system happy if someone 1404 * did a write before quota was turned on 1405 */ 1406 rsv = inode_get_rsv_space(inode); 1407 if (unlikely(rsv)) 1408 dquot_resv_space(inode->i_dquot[cnt], rsv); 1409 } 1410 } 1411 out_err: 1412 up_write(&sb_dqopt(sb)->dqptr_sem); 1413 /* Drop unused references */ 1414 dqput_all(got); 1415 } 1416 1417 void dquot_initialize(struct inode *inode) 1418 { 1419 __dquot_initialize(inode, -1); 1420 } 1421 EXPORT_SYMBOL(dquot_initialize); 1422 1423 /* 1424 * Release all quotas referenced by inode 1425 */ 1426 static void __dquot_drop(struct inode *inode) 1427 { 1428 int cnt; 1429 struct dquot *put[MAXQUOTAS]; 1430 1431 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1432 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1433 put[cnt] = inode->i_dquot[cnt]; 1434 inode->i_dquot[cnt] = NULL; 1435 } 1436 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1437 dqput_all(put); 1438 } 1439 1440 void dquot_drop(struct inode *inode) 1441 { 1442 int cnt; 1443 1444 if (IS_NOQUOTA(inode)) 1445 return; 1446 1447 /* 1448 * Test before calling to rule out calls from proc and such 1449 * where we are not allowed to block. Note that this is 1450 * actually reliable test even without the lock - the caller 1451 * must assure that nobody can come after the DQUOT_DROP and 1452 * add quota pointers back anyway. 1453 */ 1454 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1455 if (inode->i_dquot[cnt]) 1456 break; 1457 } 1458 1459 if (cnt < MAXQUOTAS) 1460 __dquot_drop(inode); 1461 } 1462 EXPORT_SYMBOL(dquot_drop); 1463 1464 /* 1465 * inode_reserved_space is managed internally by quota, and protected by 1466 * i_lock similar to i_blocks+i_bytes. 1467 */ 1468 static qsize_t *inode_reserved_space(struct inode * inode) 1469 { 1470 /* Filesystem must explicitly define it's own method in order to use 1471 * quota reservation interface */ 1472 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1473 return inode->i_sb->dq_op->get_reserved_space(inode); 1474 } 1475 1476 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1477 { 1478 spin_lock(&inode->i_lock); 1479 *inode_reserved_space(inode) += number; 1480 spin_unlock(&inode->i_lock); 1481 } 1482 EXPORT_SYMBOL(inode_add_rsv_space); 1483 1484 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1485 { 1486 spin_lock(&inode->i_lock); 1487 *inode_reserved_space(inode) -= number; 1488 __inode_add_bytes(inode, number); 1489 spin_unlock(&inode->i_lock); 1490 } 1491 EXPORT_SYMBOL(inode_claim_rsv_space); 1492 1493 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1494 { 1495 spin_lock(&inode->i_lock); 1496 *inode_reserved_space(inode) -= number; 1497 spin_unlock(&inode->i_lock); 1498 } 1499 EXPORT_SYMBOL(inode_sub_rsv_space); 1500 1501 static qsize_t inode_get_rsv_space(struct inode *inode) 1502 { 1503 qsize_t ret; 1504 1505 if (!inode->i_sb->dq_op->get_reserved_space) 1506 return 0; 1507 spin_lock(&inode->i_lock); 1508 ret = *inode_reserved_space(inode); 1509 spin_unlock(&inode->i_lock); 1510 return ret; 1511 } 1512 1513 static void inode_incr_space(struct inode *inode, qsize_t number, 1514 int reserve) 1515 { 1516 if (reserve) 1517 inode_add_rsv_space(inode, number); 1518 else 1519 inode_add_bytes(inode, number); 1520 } 1521 1522 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1523 { 1524 if (reserve) 1525 inode_sub_rsv_space(inode, number); 1526 else 1527 inode_sub_bytes(inode, number); 1528 } 1529 1530 /* 1531 * This functions updates i_blocks+i_bytes fields and quota information 1532 * (together with appropriate checks). 1533 * 1534 * NOTE: We absolutely rely on the fact that caller dirties the inode 1535 * (usually helpers in quotaops.h care about this) and holds a handle for 1536 * the current transaction so that dquot write and inode write go into the 1537 * same transaction. 1538 */ 1539 1540 /* 1541 * This operation can block, but only after everything is updated 1542 */ 1543 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1544 { 1545 int cnt, ret = 0; 1546 char warntype[MAXQUOTAS]; 1547 int warn = flags & DQUOT_SPACE_WARN; 1548 int reserve = flags & DQUOT_SPACE_RESERVE; 1549 int nofail = flags & DQUOT_SPACE_NOFAIL; 1550 1551 /* 1552 * First test before acquiring mutex - solves deadlocks when we 1553 * re-enter the quota code and are already holding the mutex 1554 */ 1555 if (!dquot_active(inode)) { 1556 inode_incr_space(inode, number, reserve); 1557 goto out; 1558 } 1559 1560 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1561 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1562 warntype[cnt] = QUOTA_NL_NOWARN; 1563 1564 spin_lock(&dq_data_lock); 1565 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1566 if (!inode->i_dquot[cnt]) 1567 continue; 1568 ret = check_bdq(inode->i_dquot[cnt], number, !warn, 1569 warntype+cnt); 1570 if (ret && !nofail) { 1571 spin_unlock(&dq_data_lock); 1572 goto out_flush_warn; 1573 } 1574 } 1575 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1576 if (!inode->i_dquot[cnt]) 1577 continue; 1578 if (reserve) 1579 dquot_resv_space(inode->i_dquot[cnt], number); 1580 else 1581 dquot_incr_space(inode->i_dquot[cnt], number); 1582 } 1583 inode_incr_space(inode, number, reserve); 1584 spin_unlock(&dq_data_lock); 1585 1586 if (reserve) 1587 goto out_flush_warn; 1588 mark_all_dquot_dirty(inode->i_dquot); 1589 out_flush_warn: 1590 flush_warnings(inode->i_dquot, warntype); 1591 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1592 out: 1593 return ret; 1594 } 1595 EXPORT_SYMBOL(__dquot_alloc_space); 1596 1597 /* 1598 * This operation can block, but only after everything is updated 1599 */ 1600 int dquot_alloc_inode(const struct inode *inode) 1601 { 1602 int cnt, ret = 0; 1603 char warntype[MAXQUOTAS]; 1604 1605 /* First test before acquiring mutex - solves deadlocks when we 1606 * re-enter the quota code and are already holding the mutex */ 1607 if (!dquot_active(inode)) 1608 return 0; 1609 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1610 warntype[cnt] = QUOTA_NL_NOWARN; 1611 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1612 spin_lock(&dq_data_lock); 1613 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1614 if (!inode->i_dquot[cnt]) 1615 continue; 1616 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt); 1617 if (ret) 1618 goto warn_put_all; 1619 } 1620 1621 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1622 if (!inode->i_dquot[cnt]) 1623 continue; 1624 dquot_incr_inodes(inode->i_dquot[cnt], 1); 1625 } 1626 1627 warn_put_all: 1628 spin_unlock(&dq_data_lock); 1629 if (ret == 0) 1630 mark_all_dquot_dirty(inode->i_dquot); 1631 flush_warnings(inode->i_dquot, warntype); 1632 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1633 return ret; 1634 } 1635 EXPORT_SYMBOL(dquot_alloc_inode); 1636 1637 /* 1638 * Convert in-memory reserved quotas to real consumed quotas 1639 */ 1640 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1641 { 1642 int cnt; 1643 1644 if (!dquot_active(inode)) { 1645 inode_claim_rsv_space(inode, number); 1646 return 0; 1647 } 1648 1649 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1650 spin_lock(&dq_data_lock); 1651 /* Claim reserved quotas to allocated quotas */ 1652 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1653 if (inode->i_dquot[cnt]) 1654 dquot_claim_reserved_space(inode->i_dquot[cnt], 1655 number); 1656 } 1657 /* Update inode bytes */ 1658 inode_claim_rsv_space(inode, number); 1659 spin_unlock(&dq_data_lock); 1660 mark_all_dquot_dirty(inode->i_dquot); 1661 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1662 return 0; 1663 } 1664 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1665 1666 /* 1667 * This operation can block, but only after everything is updated 1668 */ 1669 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1670 { 1671 unsigned int cnt; 1672 char warntype[MAXQUOTAS]; 1673 int reserve = flags & DQUOT_SPACE_RESERVE; 1674 1675 /* First test before acquiring mutex - solves deadlocks when we 1676 * re-enter the quota code and are already holding the mutex */ 1677 if (!dquot_active(inode)) { 1678 inode_decr_space(inode, number, reserve); 1679 return; 1680 } 1681 1682 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1683 spin_lock(&dq_data_lock); 1684 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1685 if (!inode->i_dquot[cnt]) 1686 continue; 1687 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1688 if (reserve) 1689 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1690 else 1691 dquot_decr_space(inode->i_dquot[cnt], number); 1692 } 1693 inode_decr_space(inode, number, reserve); 1694 spin_unlock(&dq_data_lock); 1695 1696 if (reserve) 1697 goto out_unlock; 1698 mark_all_dquot_dirty(inode->i_dquot); 1699 out_unlock: 1700 flush_warnings(inode->i_dquot, warntype); 1701 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1702 } 1703 EXPORT_SYMBOL(__dquot_free_space); 1704 1705 /* 1706 * This operation can block, but only after everything is updated 1707 */ 1708 void dquot_free_inode(const struct inode *inode) 1709 { 1710 unsigned int cnt; 1711 char warntype[MAXQUOTAS]; 1712 1713 /* First test before acquiring mutex - solves deadlocks when we 1714 * re-enter the quota code and are already holding the mutex */ 1715 if (!dquot_active(inode)) 1716 return; 1717 1718 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1719 spin_lock(&dq_data_lock); 1720 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1721 if (!inode->i_dquot[cnt]) 1722 continue; 1723 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1); 1724 dquot_decr_inodes(inode->i_dquot[cnt], 1); 1725 } 1726 spin_unlock(&dq_data_lock); 1727 mark_all_dquot_dirty(inode->i_dquot); 1728 flush_warnings(inode->i_dquot, warntype); 1729 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1730 } 1731 EXPORT_SYMBOL(dquot_free_inode); 1732 1733 /* 1734 * Transfer the number of inode and blocks from one diskquota to an other. 1735 * On success, dquot references in transfer_to are consumed and references 1736 * to original dquots that need to be released are placed there. On failure, 1737 * references are kept untouched. 1738 * 1739 * This operation can block, but only after everything is updated 1740 * A transaction must be started when entering this function. 1741 * 1742 */ 1743 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1744 { 1745 qsize_t space, cur_space; 1746 qsize_t rsv_space = 0; 1747 struct dquot *transfer_from[MAXQUOTAS] = {}; 1748 int cnt, ret = 0; 1749 char is_valid[MAXQUOTAS] = {}; 1750 char warntype_to[MAXQUOTAS]; 1751 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1752 1753 /* First test before acquiring mutex - solves deadlocks when we 1754 * re-enter the quota code and are already holding the mutex */ 1755 if (IS_NOQUOTA(inode)) 1756 return 0; 1757 /* Initialize the arrays */ 1758 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1759 warntype_to[cnt] = QUOTA_NL_NOWARN; 1760 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1761 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1762 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1763 return 0; 1764 } 1765 spin_lock(&dq_data_lock); 1766 cur_space = inode_get_bytes(inode); 1767 rsv_space = inode_get_rsv_space(inode); 1768 space = cur_space + rsv_space; 1769 /* Build the transfer_from list and check the limits */ 1770 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1771 /* 1772 * Skip changes for same uid or gid or for turned off quota-type. 1773 */ 1774 if (!transfer_to[cnt]) 1775 continue; 1776 /* Avoid races with quotaoff() */ 1777 if (!sb_has_quota_active(inode->i_sb, cnt)) 1778 continue; 1779 is_valid[cnt] = 1; 1780 transfer_from[cnt] = inode->i_dquot[cnt]; 1781 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt); 1782 if (ret) 1783 goto over_quota; 1784 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt); 1785 if (ret) 1786 goto over_quota; 1787 } 1788 1789 /* 1790 * Finally perform the needed transfer from transfer_from to transfer_to 1791 */ 1792 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1793 if (!is_valid[cnt]) 1794 continue; 1795 /* Due to IO error we might not have transfer_from[] structure */ 1796 if (transfer_from[cnt]) { 1797 warntype_from_inodes[cnt] = 1798 info_idq_free(transfer_from[cnt], 1); 1799 warntype_from_space[cnt] = 1800 info_bdq_free(transfer_from[cnt], space); 1801 dquot_decr_inodes(transfer_from[cnt], 1); 1802 dquot_decr_space(transfer_from[cnt], cur_space); 1803 dquot_free_reserved_space(transfer_from[cnt], 1804 rsv_space); 1805 } 1806 1807 dquot_incr_inodes(transfer_to[cnt], 1); 1808 dquot_incr_space(transfer_to[cnt], cur_space); 1809 dquot_resv_space(transfer_to[cnt], rsv_space); 1810 1811 inode->i_dquot[cnt] = transfer_to[cnt]; 1812 } 1813 spin_unlock(&dq_data_lock); 1814 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1815 1816 mark_all_dquot_dirty(transfer_from); 1817 mark_all_dquot_dirty(transfer_to); 1818 flush_warnings(transfer_to, warntype_to); 1819 flush_warnings(transfer_from, warntype_from_inodes); 1820 flush_warnings(transfer_from, warntype_from_space); 1821 /* Pass back references to put */ 1822 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1823 if (is_valid[cnt]) 1824 transfer_to[cnt] = transfer_from[cnt]; 1825 return 0; 1826 over_quota: 1827 spin_unlock(&dq_data_lock); 1828 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1829 flush_warnings(transfer_to, warntype_to); 1830 return ret; 1831 } 1832 EXPORT_SYMBOL(__dquot_transfer); 1833 1834 /* Wrapper for transferring ownership of an inode for uid/gid only 1835 * Called from FSXXX_setattr() 1836 */ 1837 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1838 { 1839 struct dquot *transfer_to[MAXQUOTAS] = {}; 1840 struct super_block *sb = inode->i_sb; 1841 int ret; 1842 1843 if (!dquot_active(inode)) 1844 return 0; 1845 1846 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) 1847 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA); 1848 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) 1849 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA); 1850 1851 ret = __dquot_transfer(inode, transfer_to); 1852 dqput_all(transfer_to); 1853 return ret; 1854 } 1855 EXPORT_SYMBOL(dquot_transfer); 1856 1857 /* 1858 * Write info of quota file to disk 1859 */ 1860 int dquot_commit_info(struct super_block *sb, int type) 1861 { 1862 int ret; 1863 struct quota_info *dqopt = sb_dqopt(sb); 1864 1865 mutex_lock(&dqopt->dqio_mutex); 1866 ret = dqopt->ops[type]->write_file_info(sb, type); 1867 mutex_unlock(&dqopt->dqio_mutex); 1868 return ret; 1869 } 1870 EXPORT_SYMBOL(dquot_commit_info); 1871 1872 /* 1873 * Definitions of diskquota operations. 1874 */ 1875 const struct dquot_operations dquot_operations = { 1876 .write_dquot = dquot_commit, 1877 .acquire_dquot = dquot_acquire, 1878 .release_dquot = dquot_release, 1879 .mark_dirty = dquot_mark_dquot_dirty, 1880 .write_info = dquot_commit_info, 1881 .alloc_dquot = dquot_alloc, 1882 .destroy_dquot = dquot_destroy, 1883 }; 1884 EXPORT_SYMBOL(dquot_operations); 1885 1886 /* 1887 * Generic helper for ->open on filesystems supporting disk quotas. 1888 */ 1889 int dquot_file_open(struct inode *inode, struct file *file) 1890 { 1891 int error; 1892 1893 error = generic_file_open(inode, file); 1894 if (!error && (file->f_mode & FMODE_WRITE)) 1895 dquot_initialize(inode); 1896 return error; 1897 } 1898 EXPORT_SYMBOL(dquot_file_open); 1899 1900 /* 1901 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1902 */ 1903 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 1904 { 1905 int cnt, ret = 0; 1906 struct quota_info *dqopt = sb_dqopt(sb); 1907 struct inode *toputinode[MAXQUOTAS]; 1908 1909 /* Cannot turn off usage accounting without turning off limits, or 1910 * suspend quotas and simultaneously turn quotas off. */ 1911 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1912 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1913 DQUOT_USAGE_ENABLED))) 1914 return -EINVAL; 1915 1916 /* We need to serialize quota_off() for device */ 1917 mutex_lock(&dqopt->dqonoff_mutex); 1918 1919 /* 1920 * Skip everything if there's nothing to do. We have to do this because 1921 * sometimes we are called when fill_super() failed and calling 1922 * sync_fs() in such cases does no good. 1923 */ 1924 if (!sb_any_quota_loaded(sb)) { 1925 mutex_unlock(&dqopt->dqonoff_mutex); 1926 return 0; 1927 } 1928 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1929 toputinode[cnt] = NULL; 1930 if (type != -1 && cnt != type) 1931 continue; 1932 if (!sb_has_quota_loaded(sb, cnt)) 1933 continue; 1934 1935 if (flags & DQUOT_SUSPENDED) { 1936 spin_lock(&dq_state_lock); 1937 dqopt->flags |= 1938 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1939 spin_unlock(&dq_state_lock); 1940 } else { 1941 spin_lock(&dq_state_lock); 1942 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1943 /* Turning off suspended quotas? */ 1944 if (!sb_has_quota_loaded(sb, cnt) && 1945 sb_has_quota_suspended(sb, cnt)) { 1946 dqopt->flags &= ~dquot_state_flag( 1947 DQUOT_SUSPENDED, cnt); 1948 spin_unlock(&dq_state_lock); 1949 iput(dqopt->files[cnt]); 1950 dqopt->files[cnt] = NULL; 1951 continue; 1952 } 1953 spin_unlock(&dq_state_lock); 1954 } 1955 1956 /* We still have to keep quota loaded? */ 1957 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1958 continue; 1959 1960 /* Note: these are blocking operations */ 1961 drop_dquot_ref(sb, cnt); 1962 invalidate_dquots(sb, cnt); 1963 /* 1964 * Now all dquots should be invalidated, all writes done so we 1965 * should be only users of the info. No locks needed. 1966 */ 1967 if (info_dirty(&dqopt->info[cnt])) 1968 sb->dq_op->write_info(sb, cnt); 1969 if (dqopt->ops[cnt]->free_file_info) 1970 dqopt->ops[cnt]->free_file_info(sb, cnt); 1971 put_quota_format(dqopt->info[cnt].dqi_format); 1972 1973 toputinode[cnt] = dqopt->files[cnt]; 1974 if (!sb_has_quota_loaded(sb, cnt)) 1975 dqopt->files[cnt] = NULL; 1976 dqopt->info[cnt].dqi_flags = 0; 1977 dqopt->info[cnt].dqi_igrace = 0; 1978 dqopt->info[cnt].dqi_bgrace = 0; 1979 dqopt->ops[cnt] = NULL; 1980 } 1981 mutex_unlock(&dqopt->dqonoff_mutex); 1982 1983 /* Skip syncing and setting flags if quota files are hidden */ 1984 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1985 goto put_inodes; 1986 1987 /* Sync the superblock so that buffers with quota data are written to 1988 * disk (and so userspace sees correct data afterwards). */ 1989 if (sb->s_op->sync_fs) 1990 sb->s_op->sync_fs(sb, 1); 1991 sync_blockdev(sb->s_bdev); 1992 /* Now the quota files are just ordinary files and we can set the 1993 * inode flags back. Moreover we discard the pagecache so that 1994 * userspace sees the writes we did bypassing the pagecache. We 1995 * must also discard the blockdev buffers so that we see the 1996 * changes done by userspace on the next quotaon() */ 1997 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1998 if (toputinode[cnt]) { 1999 mutex_lock(&dqopt->dqonoff_mutex); 2000 /* If quota was reenabled in the meantime, we have 2001 * nothing to do */ 2002 if (!sb_has_quota_loaded(sb, cnt)) { 2003 mutex_lock_nested(&toputinode[cnt]->i_mutex, 2004 I_MUTEX_QUOTA); 2005 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 2006 S_NOATIME | S_NOQUOTA); 2007 truncate_inode_pages(&toputinode[cnt]->i_data, 2008 0); 2009 mutex_unlock(&toputinode[cnt]->i_mutex); 2010 mark_inode_dirty_sync(toputinode[cnt]); 2011 } 2012 mutex_unlock(&dqopt->dqonoff_mutex); 2013 } 2014 if (sb->s_bdev) 2015 invalidate_bdev(sb->s_bdev); 2016 put_inodes: 2017 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2018 if (toputinode[cnt]) { 2019 /* On remount RO, we keep the inode pointer so that we 2020 * can reenable quota on the subsequent remount RW. We 2021 * have to check 'flags' variable and not use sb_has_ 2022 * function because another quotaon / quotaoff could 2023 * change global state before we got here. We refuse 2024 * to suspend quotas when there is pending delete on 2025 * the quota file... */ 2026 if (!(flags & DQUOT_SUSPENDED)) 2027 iput(toputinode[cnt]); 2028 else if (!toputinode[cnt]->i_nlink) 2029 ret = -EBUSY; 2030 } 2031 return ret; 2032 } 2033 EXPORT_SYMBOL(dquot_disable); 2034 2035 int dquot_quota_off(struct super_block *sb, int type) 2036 { 2037 return dquot_disable(sb, type, 2038 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2039 } 2040 EXPORT_SYMBOL(dquot_quota_off); 2041 2042 /* 2043 * Turn quotas on on a device 2044 */ 2045 2046 /* 2047 * Helper function to turn quotas on when we already have the inode of 2048 * quota file and no quota information is loaded. 2049 */ 2050 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2051 unsigned int flags) 2052 { 2053 struct quota_format_type *fmt = find_quota_format(format_id); 2054 struct super_block *sb = inode->i_sb; 2055 struct quota_info *dqopt = sb_dqopt(sb); 2056 int error; 2057 int oldflags = -1; 2058 2059 if (!fmt) 2060 return -ESRCH; 2061 if (!S_ISREG(inode->i_mode)) { 2062 error = -EACCES; 2063 goto out_fmt; 2064 } 2065 if (IS_RDONLY(inode)) { 2066 error = -EROFS; 2067 goto out_fmt; 2068 } 2069 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 2070 error = -EINVAL; 2071 goto out_fmt; 2072 } 2073 /* Usage always has to be set... */ 2074 if (!(flags & DQUOT_USAGE_ENABLED)) { 2075 error = -EINVAL; 2076 goto out_fmt; 2077 } 2078 2079 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2080 /* As we bypass the pagecache we must now flush all the 2081 * dirty data and invalidate caches so that kernel sees 2082 * changes from userspace. It is not enough to just flush 2083 * the quota file since if blocksize < pagesize, invalidation 2084 * of the cache could fail because of other unrelated dirty 2085 * data */ 2086 sync_filesystem(sb); 2087 invalidate_bdev(sb->s_bdev); 2088 } 2089 mutex_lock(&dqopt->dqonoff_mutex); 2090 if (sb_has_quota_loaded(sb, type)) { 2091 error = -EBUSY; 2092 goto out_lock; 2093 } 2094 2095 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2096 /* We don't want quota and atime on quota files (deadlocks 2097 * possible) Also nobody should write to the file - we use 2098 * special IO operations which ignore the immutable bit. */ 2099 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2100 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2101 S_NOQUOTA); 2102 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2103 mutex_unlock(&inode->i_mutex); 2104 /* 2105 * When S_NOQUOTA is set, remove dquot references as no more 2106 * references can be added 2107 */ 2108 __dquot_drop(inode); 2109 } 2110 2111 error = -EIO; 2112 dqopt->files[type] = igrab(inode); 2113 if (!dqopt->files[type]) 2114 goto out_lock; 2115 error = -EINVAL; 2116 if (!fmt->qf_ops->check_quota_file(sb, type)) 2117 goto out_file_init; 2118 2119 dqopt->ops[type] = fmt->qf_ops; 2120 dqopt->info[type].dqi_format = fmt; 2121 dqopt->info[type].dqi_fmt_id = format_id; 2122 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2123 mutex_lock(&dqopt->dqio_mutex); 2124 error = dqopt->ops[type]->read_file_info(sb, type); 2125 if (error < 0) { 2126 mutex_unlock(&dqopt->dqio_mutex); 2127 goto out_file_init; 2128 } 2129 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2130 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2131 mutex_unlock(&dqopt->dqio_mutex); 2132 spin_lock(&dq_state_lock); 2133 dqopt->flags |= dquot_state_flag(flags, type); 2134 spin_unlock(&dq_state_lock); 2135 2136 add_dquot_ref(sb, type); 2137 mutex_unlock(&dqopt->dqonoff_mutex); 2138 2139 return 0; 2140 2141 out_file_init: 2142 dqopt->files[type] = NULL; 2143 iput(inode); 2144 out_lock: 2145 if (oldflags != -1) { 2146 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2147 /* Set the flags back (in the case of accidental quotaon() 2148 * on a wrong file we don't want to mess up the flags) */ 2149 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2150 inode->i_flags |= oldflags; 2151 mutex_unlock(&inode->i_mutex); 2152 } 2153 mutex_unlock(&dqopt->dqonoff_mutex); 2154 out_fmt: 2155 put_quota_format(fmt); 2156 2157 return error; 2158 } 2159 2160 /* Reenable quotas on remount RW */ 2161 int dquot_resume(struct super_block *sb, int type) 2162 { 2163 struct quota_info *dqopt = sb_dqopt(sb); 2164 struct inode *inode; 2165 int ret = 0, cnt; 2166 unsigned int flags; 2167 2168 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2169 if (type != -1 && cnt != type) 2170 continue; 2171 2172 mutex_lock(&dqopt->dqonoff_mutex); 2173 if (!sb_has_quota_suspended(sb, cnt)) { 2174 mutex_unlock(&dqopt->dqonoff_mutex); 2175 continue; 2176 } 2177 inode = dqopt->files[cnt]; 2178 dqopt->files[cnt] = NULL; 2179 spin_lock(&dq_state_lock); 2180 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2181 DQUOT_LIMITS_ENABLED, 2182 cnt); 2183 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2184 spin_unlock(&dq_state_lock); 2185 mutex_unlock(&dqopt->dqonoff_mutex); 2186 2187 flags = dquot_generic_flag(flags, cnt); 2188 ret = vfs_load_quota_inode(inode, cnt, 2189 dqopt->info[cnt].dqi_fmt_id, flags); 2190 iput(inode); 2191 } 2192 2193 return ret; 2194 } 2195 EXPORT_SYMBOL(dquot_resume); 2196 2197 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2198 struct path *path) 2199 { 2200 int error = security_quota_on(path->dentry); 2201 if (error) 2202 return error; 2203 /* Quota file not on the same filesystem? */ 2204 if (path->dentry->d_sb != sb) 2205 error = -EXDEV; 2206 else 2207 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2208 format_id, DQUOT_USAGE_ENABLED | 2209 DQUOT_LIMITS_ENABLED); 2210 return error; 2211 } 2212 EXPORT_SYMBOL(dquot_quota_on); 2213 2214 /* 2215 * More powerful function for turning on quotas allowing setting 2216 * of individual quota flags 2217 */ 2218 int dquot_enable(struct inode *inode, int type, int format_id, 2219 unsigned int flags) 2220 { 2221 int ret = 0; 2222 struct super_block *sb = inode->i_sb; 2223 struct quota_info *dqopt = sb_dqopt(sb); 2224 2225 /* Just unsuspend quotas? */ 2226 BUG_ON(flags & DQUOT_SUSPENDED); 2227 2228 if (!flags) 2229 return 0; 2230 /* Just updating flags needed? */ 2231 if (sb_has_quota_loaded(sb, type)) { 2232 mutex_lock(&dqopt->dqonoff_mutex); 2233 /* Now do a reliable test... */ 2234 if (!sb_has_quota_loaded(sb, type)) { 2235 mutex_unlock(&dqopt->dqonoff_mutex); 2236 goto load_quota; 2237 } 2238 if (flags & DQUOT_USAGE_ENABLED && 2239 sb_has_quota_usage_enabled(sb, type)) { 2240 ret = -EBUSY; 2241 goto out_lock; 2242 } 2243 if (flags & DQUOT_LIMITS_ENABLED && 2244 sb_has_quota_limits_enabled(sb, type)) { 2245 ret = -EBUSY; 2246 goto out_lock; 2247 } 2248 spin_lock(&dq_state_lock); 2249 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2250 spin_unlock(&dq_state_lock); 2251 out_lock: 2252 mutex_unlock(&dqopt->dqonoff_mutex); 2253 return ret; 2254 } 2255 2256 load_quota: 2257 return vfs_load_quota_inode(inode, type, format_id, flags); 2258 } 2259 EXPORT_SYMBOL(dquot_enable); 2260 2261 /* 2262 * This function is used when filesystem needs to initialize quotas 2263 * during mount time. 2264 */ 2265 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2266 int format_id, int type) 2267 { 2268 struct dentry *dentry; 2269 int error; 2270 2271 mutex_lock(&sb->s_root->d_inode->i_mutex); 2272 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2273 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2274 if (IS_ERR(dentry)) 2275 return PTR_ERR(dentry); 2276 2277 if (!dentry->d_inode) { 2278 error = -ENOENT; 2279 goto out; 2280 } 2281 2282 error = security_quota_on(dentry); 2283 if (!error) 2284 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2285 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2286 2287 out: 2288 dput(dentry); 2289 return error; 2290 } 2291 EXPORT_SYMBOL(dquot_quota_on_mount); 2292 2293 static inline qsize_t qbtos(qsize_t blocks) 2294 { 2295 return blocks << QIF_DQBLKSIZE_BITS; 2296 } 2297 2298 static inline qsize_t stoqb(qsize_t space) 2299 { 2300 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2301 } 2302 2303 /* Generic routine for getting common part of quota structure */ 2304 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2305 { 2306 struct mem_dqblk *dm = &dquot->dq_dqb; 2307 2308 memset(di, 0, sizeof(*di)); 2309 di->d_version = FS_DQUOT_VERSION; 2310 di->d_flags = dquot->dq_type == USRQUOTA ? 2311 FS_USER_QUOTA : FS_GROUP_QUOTA; 2312 di->d_id = dquot->dq_id; 2313 2314 spin_lock(&dq_data_lock); 2315 di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit); 2316 di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit); 2317 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2318 di->d_ino_softlimit = dm->dqb_isoftlimit; 2319 di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace; 2320 di->d_icount = dm->dqb_curinodes; 2321 di->d_btimer = dm->dqb_btime; 2322 di->d_itimer = dm->dqb_itime; 2323 spin_unlock(&dq_data_lock); 2324 } 2325 2326 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id, 2327 struct fs_disk_quota *di) 2328 { 2329 struct dquot *dquot; 2330 2331 dquot = dqget(sb, id, type); 2332 if (!dquot) 2333 return -ESRCH; 2334 do_get_dqblk(dquot, di); 2335 dqput(dquot); 2336 2337 return 0; 2338 } 2339 EXPORT_SYMBOL(dquot_get_dqblk); 2340 2341 #define VFS_FS_DQ_MASK \ 2342 (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \ 2343 FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \ 2344 FS_DQ_BTIMER | FS_DQ_ITIMER) 2345 2346 /* Generic routine for setting common part of quota structure */ 2347 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2348 { 2349 struct mem_dqblk *dm = &dquot->dq_dqb; 2350 int check_blim = 0, check_ilim = 0; 2351 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2352 2353 if (di->d_fieldmask & ~VFS_FS_DQ_MASK) 2354 return -EINVAL; 2355 2356 if (((di->d_fieldmask & FS_DQ_BSOFT) && 2357 (di->d_blk_softlimit > dqi->dqi_maxblimit)) || 2358 ((di->d_fieldmask & FS_DQ_BHARD) && 2359 (di->d_blk_hardlimit > dqi->dqi_maxblimit)) || 2360 ((di->d_fieldmask & FS_DQ_ISOFT) && 2361 (di->d_ino_softlimit > dqi->dqi_maxilimit)) || 2362 ((di->d_fieldmask & FS_DQ_IHARD) && 2363 (di->d_ino_hardlimit > dqi->dqi_maxilimit))) 2364 return -ERANGE; 2365 2366 spin_lock(&dq_data_lock); 2367 if (di->d_fieldmask & FS_DQ_BCOUNT) { 2368 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace; 2369 check_blim = 1; 2370 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2371 } 2372 2373 if (di->d_fieldmask & FS_DQ_BSOFT) 2374 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit); 2375 if (di->d_fieldmask & FS_DQ_BHARD) 2376 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit); 2377 if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) { 2378 check_blim = 1; 2379 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2380 } 2381 2382 if (di->d_fieldmask & FS_DQ_ICOUNT) { 2383 dm->dqb_curinodes = di->d_icount; 2384 check_ilim = 1; 2385 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2386 } 2387 2388 if (di->d_fieldmask & FS_DQ_ISOFT) 2389 dm->dqb_isoftlimit = di->d_ino_softlimit; 2390 if (di->d_fieldmask & FS_DQ_IHARD) 2391 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2392 if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) { 2393 check_ilim = 1; 2394 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2395 } 2396 2397 if (di->d_fieldmask & FS_DQ_BTIMER) { 2398 dm->dqb_btime = di->d_btimer; 2399 check_blim = 1; 2400 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2401 } 2402 2403 if (di->d_fieldmask & FS_DQ_ITIMER) { 2404 dm->dqb_itime = di->d_itimer; 2405 check_ilim = 1; 2406 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2407 } 2408 2409 if (check_blim) { 2410 if (!dm->dqb_bsoftlimit || 2411 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2412 dm->dqb_btime = 0; 2413 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2414 } else if (!(di->d_fieldmask & FS_DQ_BTIMER)) 2415 /* Set grace only if user hasn't provided his own... */ 2416 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2417 } 2418 if (check_ilim) { 2419 if (!dm->dqb_isoftlimit || 2420 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2421 dm->dqb_itime = 0; 2422 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2423 } else if (!(di->d_fieldmask & FS_DQ_ITIMER)) 2424 /* Set grace only if user hasn't provided his own... */ 2425 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2426 } 2427 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2428 dm->dqb_isoftlimit) 2429 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2430 else 2431 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2432 spin_unlock(&dq_data_lock); 2433 mark_dquot_dirty(dquot); 2434 2435 return 0; 2436 } 2437 2438 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id, 2439 struct fs_disk_quota *di) 2440 { 2441 struct dquot *dquot; 2442 int rc; 2443 2444 dquot = dqget(sb, id, type); 2445 if (!dquot) { 2446 rc = -ESRCH; 2447 goto out; 2448 } 2449 rc = do_set_dqblk(dquot, di); 2450 dqput(dquot); 2451 out: 2452 return rc; 2453 } 2454 EXPORT_SYMBOL(dquot_set_dqblk); 2455 2456 /* Generic routine for getting common part of quota file information */ 2457 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2458 { 2459 struct mem_dqinfo *mi; 2460 2461 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2462 if (!sb_has_quota_active(sb, type)) { 2463 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2464 return -ESRCH; 2465 } 2466 mi = sb_dqopt(sb)->info + type; 2467 spin_lock(&dq_data_lock); 2468 ii->dqi_bgrace = mi->dqi_bgrace; 2469 ii->dqi_igrace = mi->dqi_igrace; 2470 ii->dqi_flags = mi->dqi_flags & DQF_GETINFO_MASK; 2471 ii->dqi_valid = IIF_ALL; 2472 spin_unlock(&dq_data_lock); 2473 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2474 return 0; 2475 } 2476 EXPORT_SYMBOL(dquot_get_dqinfo); 2477 2478 /* Generic routine for setting common part of quota file information */ 2479 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2480 { 2481 struct mem_dqinfo *mi; 2482 int err = 0; 2483 2484 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2485 if (!sb_has_quota_active(sb, type)) { 2486 err = -ESRCH; 2487 goto out; 2488 } 2489 mi = sb_dqopt(sb)->info + type; 2490 spin_lock(&dq_data_lock); 2491 if (ii->dqi_valid & IIF_BGRACE) 2492 mi->dqi_bgrace = ii->dqi_bgrace; 2493 if (ii->dqi_valid & IIF_IGRACE) 2494 mi->dqi_igrace = ii->dqi_igrace; 2495 if (ii->dqi_valid & IIF_FLAGS) 2496 mi->dqi_flags = (mi->dqi_flags & ~DQF_SETINFO_MASK) | 2497 (ii->dqi_flags & DQF_SETINFO_MASK); 2498 spin_unlock(&dq_data_lock); 2499 mark_info_dirty(sb, type); 2500 /* Force write to disk */ 2501 sb->dq_op->write_info(sb, type); 2502 out: 2503 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2504 return err; 2505 } 2506 EXPORT_SYMBOL(dquot_set_dqinfo); 2507 2508 const struct quotactl_ops dquot_quotactl_ops = { 2509 .quota_on = dquot_quota_on, 2510 .quota_off = dquot_quota_off, 2511 .quota_sync = dquot_quota_sync, 2512 .get_info = dquot_get_dqinfo, 2513 .set_info = dquot_set_dqinfo, 2514 .get_dqblk = dquot_get_dqblk, 2515 .set_dqblk = dquot_set_dqblk 2516 }; 2517 EXPORT_SYMBOL(dquot_quotactl_ops); 2518 2519 static int do_proc_dqstats(struct ctl_table *table, int write, 2520 void __user *buffer, size_t *lenp, loff_t *ppos) 2521 { 2522 unsigned int type = (int *)table->data - dqstats.stat; 2523 2524 /* Update global table */ 2525 dqstats.stat[type] = 2526 percpu_counter_sum_positive(&dqstats.counter[type]); 2527 return proc_dointvec(table, write, buffer, lenp, ppos); 2528 } 2529 2530 static ctl_table fs_dqstats_table[] = { 2531 { 2532 .procname = "lookups", 2533 .data = &dqstats.stat[DQST_LOOKUPS], 2534 .maxlen = sizeof(int), 2535 .mode = 0444, 2536 .proc_handler = do_proc_dqstats, 2537 }, 2538 { 2539 .procname = "drops", 2540 .data = &dqstats.stat[DQST_DROPS], 2541 .maxlen = sizeof(int), 2542 .mode = 0444, 2543 .proc_handler = do_proc_dqstats, 2544 }, 2545 { 2546 .procname = "reads", 2547 .data = &dqstats.stat[DQST_READS], 2548 .maxlen = sizeof(int), 2549 .mode = 0444, 2550 .proc_handler = do_proc_dqstats, 2551 }, 2552 { 2553 .procname = "writes", 2554 .data = &dqstats.stat[DQST_WRITES], 2555 .maxlen = sizeof(int), 2556 .mode = 0444, 2557 .proc_handler = do_proc_dqstats, 2558 }, 2559 { 2560 .procname = "cache_hits", 2561 .data = &dqstats.stat[DQST_CACHE_HITS], 2562 .maxlen = sizeof(int), 2563 .mode = 0444, 2564 .proc_handler = do_proc_dqstats, 2565 }, 2566 { 2567 .procname = "allocated_dquots", 2568 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2569 .maxlen = sizeof(int), 2570 .mode = 0444, 2571 .proc_handler = do_proc_dqstats, 2572 }, 2573 { 2574 .procname = "free_dquots", 2575 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2576 .maxlen = sizeof(int), 2577 .mode = 0444, 2578 .proc_handler = do_proc_dqstats, 2579 }, 2580 { 2581 .procname = "syncs", 2582 .data = &dqstats.stat[DQST_SYNCS], 2583 .maxlen = sizeof(int), 2584 .mode = 0444, 2585 .proc_handler = do_proc_dqstats, 2586 }, 2587 #ifdef CONFIG_PRINT_QUOTA_WARNING 2588 { 2589 .procname = "warnings", 2590 .data = &flag_print_warnings, 2591 .maxlen = sizeof(int), 2592 .mode = 0644, 2593 .proc_handler = proc_dointvec, 2594 }, 2595 #endif 2596 { }, 2597 }; 2598 2599 static ctl_table fs_table[] = { 2600 { 2601 .procname = "quota", 2602 .mode = 0555, 2603 .child = fs_dqstats_table, 2604 }, 2605 { }, 2606 }; 2607 2608 static ctl_table sys_table[] = { 2609 { 2610 .procname = "fs", 2611 .mode = 0555, 2612 .child = fs_table, 2613 }, 2614 { }, 2615 }; 2616 2617 static int __init dquot_init(void) 2618 { 2619 int i, ret; 2620 unsigned long nr_hash, order; 2621 2622 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2623 2624 register_sysctl_table(sys_table); 2625 2626 dquot_cachep = kmem_cache_create("dquot", 2627 sizeof(struct dquot), sizeof(unsigned long) * 4, 2628 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2629 SLAB_MEM_SPREAD|SLAB_PANIC), 2630 NULL); 2631 2632 order = 0; 2633 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2634 if (!dquot_hash) 2635 panic("Cannot create dquot hash table"); 2636 2637 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2638 ret = percpu_counter_init(&dqstats.counter[i], 0); 2639 if (ret) 2640 panic("Cannot create dquot stat counters"); 2641 } 2642 2643 /* Find power-of-two hlist_heads which can fit into allocation */ 2644 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2645 dq_hash_bits = 0; 2646 do { 2647 dq_hash_bits++; 2648 } while (nr_hash >> dq_hash_bits); 2649 dq_hash_bits--; 2650 2651 nr_hash = 1UL << dq_hash_bits; 2652 dq_hash_mask = nr_hash - 1; 2653 for (i = 0; i < nr_hash; i++) 2654 INIT_HLIST_HEAD(dquot_hash + i); 2655 2656 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2657 nr_hash, order, (PAGE_SIZE << order)); 2658 2659 register_shrinker(&dqcache_shrinker); 2660 2661 return 0; 2662 } 2663 module_init(dquot_init); 2664