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/kmod.h> 75 #include <linux/namei.h> 76 #include <linux/buffer_head.h> 77 #include <linux/capability.h> 78 #include <linux/quotaops.h> 79 #include <linux/writeback.h> /* for inode_lock, oddly enough.. */ 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 va_list args; 139 140 if (printk_ratelimit()) { 141 va_start(args, fmt); 142 printk(KERN_ERR "Quota error (device %s): %s: ", 143 sb->s_id, func); 144 vprintk(fmt, args); 145 printk("\n"); 146 va_end(args); 147 } 148 } 149 EXPORT_SYMBOL(__quota_error); 150 151 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 152 static char *quotatypes[] = INITQFNAMES; 153 #endif 154 static struct quota_format_type *quota_formats; /* List of registered formats */ 155 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 156 157 /* SLAB cache for dquot structures */ 158 static struct kmem_cache *dquot_cachep; 159 160 int register_quota_format(struct quota_format_type *fmt) 161 { 162 spin_lock(&dq_list_lock); 163 fmt->qf_next = quota_formats; 164 quota_formats = fmt; 165 spin_unlock(&dq_list_lock); 166 return 0; 167 } 168 EXPORT_SYMBOL(register_quota_format); 169 170 void unregister_quota_format(struct quota_format_type *fmt) 171 { 172 struct quota_format_type **actqf; 173 174 spin_lock(&dq_list_lock); 175 for (actqf = "a_formats; *actqf && *actqf != fmt; 176 actqf = &(*actqf)->qf_next) 177 ; 178 if (*actqf) 179 *actqf = (*actqf)->qf_next; 180 spin_unlock(&dq_list_lock); 181 } 182 EXPORT_SYMBOL(unregister_quota_format); 183 184 static struct quota_format_type *find_quota_format(int id) 185 { 186 struct quota_format_type *actqf; 187 188 spin_lock(&dq_list_lock); 189 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 190 actqf = actqf->qf_next) 191 ; 192 if (!actqf || !try_module_get(actqf->qf_owner)) { 193 int qm; 194 195 spin_unlock(&dq_list_lock); 196 197 for (qm = 0; module_names[qm].qm_fmt_id && 198 module_names[qm].qm_fmt_id != id; qm++) 199 ; 200 if (!module_names[qm].qm_fmt_id || 201 request_module(module_names[qm].qm_mod_name)) 202 return NULL; 203 204 spin_lock(&dq_list_lock); 205 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 206 actqf = actqf->qf_next) 207 ; 208 if (actqf && !try_module_get(actqf->qf_owner)) 209 actqf = NULL; 210 } 211 spin_unlock(&dq_list_lock); 212 return actqf; 213 } 214 215 static void put_quota_format(struct quota_format_type *fmt) 216 { 217 module_put(fmt->qf_owner); 218 } 219 220 /* 221 * Dquot List Management: 222 * The quota code uses three lists for dquot management: the inuse_list, 223 * free_dquots, and dquot_hash[] array. A single dquot structure may be 224 * on all three lists, depending on its current state. 225 * 226 * All dquots are placed to the end of inuse_list when first created, and this 227 * list is used for invalidate operation, which must look at every dquot. 228 * 229 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 230 * and this list is searched whenever we need an available dquot. Dquots are 231 * removed from the list as soon as they are used again, and 232 * dqstats.free_dquots gives the number of dquots on the list. When 233 * dquot is invalidated it's completely released from memory. 234 * 235 * Dquots with a specific identity (device, type and id) are placed on 236 * one of the dquot_hash[] hash chains. The provides an efficient search 237 * mechanism to locate a specific dquot. 238 */ 239 240 static LIST_HEAD(inuse_list); 241 static LIST_HEAD(free_dquots); 242 static unsigned int dq_hash_bits, dq_hash_mask; 243 static struct hlist_head *dquot_hash; 244 245 struct dqstats dqstats; 246 EXPORT_SYMBOL(dqstats); 247 248 static qsize_t inode_get_rsv_space(struct inode *inode); 249 static void __dquot_initialize(struct inode *inode, int type); 250 251 static inline unsigned int 252 hashfn(const struct super_block *sb, unsigned int id, int type) 253 { 254 unsigned long tmp; 255 256 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 257 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 258 } 259 260 /* 261 * Following list functions expect dq_list_lock to be held 262 */ 263 static inline void insert_dquot_hash(struct dquot *dquot) 264 { 265 struct hlist_head *head; 266 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 267 hlist_add_head(&dquot->dq_hash, head); 268 } 269 270 static inline void remove_dquot_hash(struct dquot *dquot) 271 { 272 hlist_del_init(&dquot->dq_hash); 273 } 274 275 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 276 unsigned int id, int type) 277 { 278 struct hlist_node *node; 279 struct dquot *dquot; 280 281 hlist_for_each (node, dquot_hash+hashent) { 282 dquot = hlist_entry(node, struct dquot, dq_hash); 283 if (dquot->dq_sb == sb && dquot->dq_id == id && 284 dquot->dq_type == type) 285 return dquot; 286 } 287 return NULL; 288 } 289 290 /* Add a dquot to the tail of the free list */ 291 static inline void put_dquot_last(struct dquot *dquot) 292 { 293 list_add_tail(&dquot->dq_free, &free_dquots); 294 dqstats_inc(DQST_FREE_DQUOTS); 295 } 296 297 static inline void remove_free_dquot(struct dquot *dquot) 298 { 299 if (list_empty(&dquot->dq_free)) 300 return; 301 list_del_init(&dquot->dq_free); 302 dqstats_dec(DQST_FREE_DQUOTS); 303 } 304 305 static inline void put_inuse(struct dquot *dquot) 306 { 307 /* We add to the back of inuse list so we don't have to restart 308 * when traversing this list and we block */ 309 list_add_tail(&dquot->dq_inuse, &inuse_list); 310 dqstats_inc(DQST_ALLOC_DQUOTS); 311 } 312 313 static inline void remove_inuse(struct dquot *dquot) 314 { 315 dqstats_dec(DQST_ALLOC_DQUOTS); 316 list_del(&dquot->dq_inuse); 317 } 318 /* 319 * End of list functions needing dq_list_lock 320 */ 321 322 static void wait_on_dquot(struct dquot *dquot) 323 { 324 mutex_lock(&dquot->dq_lock); 325 mutex_unlock(&dquot->dq_lock); 326 } 327 328 static inline int dquot_dirty(struct dquot *dquot) 329 { 330 return test_bit(DQ_MOD_B, &dquot->dq_flags); 331 } 332 333 static inline int mark_dquot_dirty(struct dquot *dquot) 334 { 335 return dquot->dq_sb->dq_op->mark_dirty(dquot); 336 } 337 338 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 339 int dquot_mark_dquot_dirty(struct dquot *dquot) 340 { 341 int ret = 1; 342 343 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 344 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 345 return 1; 346 347 spin_lock(&dq_list_lock); 348 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 349 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 350 info[dquot->dq_type].dqi_dirty_list); 351 ret = 0; 352 } 353 spin_unlock(&dq_list_lock); 354 return ret; 355 } 356 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 357 358 /* Dirtify all the dquots - this can block when journalling */ 359 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 360 { 361 int ret, err, cnt; 362 363 ret = err = 0; 364 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 365 if (dquot[cnt]) 366 /* Even in case of error we have to continue */ 367 ret = mark_dquot_dirty(dquot[cnt]); 368 if (!err) 369 err = ret; 370 } 371 return err; 372 } 373 374 static inline void dqput_all(struct dquot **dquot) 375 { 376 unsigned int cnt; 377 378 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 379 dqput(dquot[cnt]); 380 } 381 382 /* This function needs dq_list_lock */ 383 static inline int clear_dquot_dirty(struct dquot *dquot) 384 { 385 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 386 return 0; 387 list_del_init(&dquot->dq_dirty); 388 return 1; 389 } 390 391 void mark_info_dirty(struct super_block *sb, int type) 392 { 393 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 394 } 395 EXPORT_SYMBOL(mark_info_dirty); 396 397 /* 398 * Read dquot from disk and alloc space for it 399 */ 400 401 int dquot_acquire(struct dquot *dquot) 402 { 403 int ret = 0, ret2 = 0; 404 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 405 406 mutex_lock(&dquot->dq_lock); 407 mutex_lock(&dqopt->dqio_mutex); 408 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 409 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 410 if (ret < 0) 411 goto out_iolock; 412 set_bit(DQ_READ_B, &dquot->dq_flags); 413 /* Instantiate dquot if needed */ 414 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 415 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 416 /* Write the info if needed */ 417 if (info_dirty(&dqopt->info[dquot->dq_type])) { 418 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 419 dquot->dq_sb, dquot->dq_type); 420 } 421 if (ret < 0) 422 goto out_iolock; 423 if (ret2 < 0) { 424 ret = ret2; 425 goto out_iolock; 426 } 427 } 428 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 429 out_iolock: 430 mutex_unlock(&dqopt->dqio_mutex); 431 mutex_unlock(&dquot->dq_lock); 432 return ret; 433 } 434 EXPORT_SYMBOL(dquot_acquire); 435 436 /* 437 * Write dquot to disk 438 */ 439 int dquot_commit(struct dquot *dquot) 440 { 441 int ret = 0, ret2 = 0; 442 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 443 444 mutex_lock(&dqopt->dqio_mutex); 445 spin_lock(&dq_list_lock); 446 if (!clear_dquot_dirty(dquot)) { 447 spin_unlock(&dq_list_lock); 448 goto out_sem; 449 } 450 spin_unlock(&dq_list_lock); 451 /* Inactive dquot can be only if there was error during read/init 452 * => we have better not writing it */ 453 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 454 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 455 if (info_dirty(&dqopt->info[dquot->dq_type])) { 456 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 457 dquot->dq_sb, dquot->dq_type); 458 } 459 if (ret >= 0) 460 ret = ret2; 461 } 462 out_sem: 463 mutex_unlock(&dqopt->dqio_mutex); 464 return ret; 465 } 466 EXPORT_SYMBOL(dquot_commit); 467 468 /* 469 * Release dquot 470 */ 471 int dquot_release(struct dquot *dquot) 472 { 473 int ret = 0, ret2 = 0; 474 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 475 476 mutex_lock(&dquot->dq_lock); 477 /* Check whether we are not racing with some other dqget() */ 478 if (atomic_read(&dquot->dq_count) > 1) 479 goto out_dqlock; 480 mutex_lock(&dqopt->dqio_mutex); 481 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 482 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 483 /* Write the info */ 484 if (info_dirty(&dqopt->info[dquot->dq_type])) { 485 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 486 dquot->dq_sb, dquot->dq_type); 487 } 488 if (ret >= 0) 489 ret = ret2; 490 } 491 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 492 mutex_unlock(&dqopt->dqio_mutex); 493 out_dqlock: 494 mutex_unlock(&dquot->dq_lock); 495 return ret; 496 } 497 EXPORT_SYMBOL(dquot_release); 498 499 void dquot_destroy(struct dquot *dquot) 500 { 501 kmem_cache_free(dquot_cachep, dquot); 502 } 503 EXPORT_SYMBOL(dquot_destroy); 504 505 static inline void do_destroy_dquot(struct dquot *dquot) 506 { 507 dquot->dq_sb->dq_op->destroy_dquot(dquot); 508 } 509 510 /* Invalidate all dquots on the list. Note that this function is called after 511 * quota is disabled and pointers from inodes removed so there cannot be new 512 * quota users. There can still be some users of quotas due to inodes being 513 * just deleted or pruned by prune_icache() (those are not attached to any 514 * list) or parallel quotactl call. We have to wait for such users. 515 */ 516 static void invalidate_dquots(struct super_block *sb, int type) 517 { 518 struct dquot *dquot, *tmp; 519 520 restart: 521 spin_lock(&dq_list_lock); 522 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 523 if (dquot->dq_sb != sb) 524 continue; 525 if (dquot->dq_type != type) 526 continue; 527 /* Wait for dquot users */ 528 if (atomic_read(&dquot->dq_count)) { 529 DEFINE_WAIT(wait); 530 531 atomic_inc(&dquot->dq_count); 532 prepare_to_wait(&dquot->dq_wait_unused, &wait, 533 TASK_UNINTERRUPTIBLE); 534 spin_unlock(&dq_list_lock); 535 /* Once dqput() wakes us up, we know it's time to free 536 * the dquot. 537 * IMPORTANT: we rely on the fact that there is always 538 * at most one process waiting for dquot to free. 539 * Otherwise dq_count would be > 1 and we would never 540 * wake up. 541 */ 542 if (atomic_read(&dquot->dq_count) > 1) 543 schedule(); 544 finish_wait(&dquot->dq_wait_unused, &wait); 545 dqput(dquot); 546 /* At this moment dquot() need not exist (it could be 547 * reclaimed by prune_dqcache(). Hence we must 548 * restart. */ 549 goto restart; 550 } 551 /* 552 * Quota now has no users and it has been written on last 553 * dqput() 554 */ 555 remove_dquot_hash(dquot); 556 remove_free_dquot(dquot); 557 remove_inuse(dquot); 558 do_destroy_dquot(dquot); 559 } 560 spin_unlock(&dq_list_lock); 561 } 562 563 /* Call callback for every active dquot on given filesystem */ 564 int dquot_scan_active(struct super_block *sb, 565 int (*fn)(struct dquot *dquot, unsigned long priv), 566 unsigned long priv) 567 { 568 struct dquot *dquot, *old_dquot = NULL; 569 int ret = 0; 570 571 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 572 spin_lock(&dq_list_lock); 573 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 574 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 575 continue; 576 if (dquot->dq_sb != sb) 577 continue; 578 /* Now we have active dquot so we can just increase use count */ 579 atomic_inc(&dquot->dq_count); 580 spin_unlock(&dq_list_lock); 581 dqstats_inc(DQST_LOOKUPS); 582 dqput(old_dquot); 583 old_dquot = dquot; 584 ret = fn(dquot, priv); 585 if (ret < 0) 586 goto out; 587 spin_lock(&dq_list_lock); 588 /* We are safe to continue now because our dquot could not 589 * be moved out of the inuse list while we hold the reference */ 590 } 591 spin_unlock(&dq_list_lock); 592 out: 593 dqput(old_dquot); 594 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 595 return ret; 596 } 597 EXPORT_SYMBOL(dquot_scan_active); 598 599 int dquot_quota_sync(struct super_block *sb, int type, int wait) 600 { 601 struct list_head *dirty; 602 struct dquot *dquot; 603 struct quota_info *dqopt = sb_dqopt(sb); 604 int cnt; 605 606 mutex_lock(&dqopt->dqonoff_mutex); 607 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 608 if (type != -1 && cnt != type) 609 continue; 610 if (!sb_has_quota_active(sb, cnt)) 611 continue; 612 spin_lock(&dq_list_lock); 613 dirty = &dqopt->info[cnt].dqi_dirty_list; 614 while (!list_empty(dirty)) { 615 dquot = list_first_entry(dirty, struct dquot, 616 dq_dirty); 617 /* Dirty and inactive can be only bad dquot... */ 618 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 619 clear_dquot_dirty(dquot); 620 continue; 621 } 622 /* Now we have active dquot from which someone is 623 * holding reference so we can safely just increase 624 * use count */ 625 atomic_inc(&dquot->dq_count); 626 spin_unlock(&dq_list_lock); 627 dqstats_inc(DQST_LOOKUPS); 628 sb->dq_op->write_dquot(dquot); 629 dqput(dquot); 630 spin_lock(&dq_list_lock); 631 } 632 spin_unlock(&dq_list_lock); 633 } 634 635 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 636 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 637 && info_dirty(&dqopt->info[cnt])) 638 sb->dq_op->write_info(sb, cnt); 639 dqstats_inc(DQST_SYNCS); 640 mutex_unlock(&dqopt->dqonoff_mutex); 641 642 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)) 643 return 0; 644 645 /* This is not very clever (and fast) but currently I don't know about 646 * any other simple way of getting quota data to disk and we must get 647 * them there for userspace to be visible... */ 648 if (sb->s_op->sync_fs) 649 sb->s_op->sync_fs(sb, 1); 650 sync_blockdev(sb->s_bdev); 651 652 /* 653 * Now when everything is written we can discard the pagecache so 654 * that userspace sees the changes. 655 */ 656 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 657 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 658 if (type != -1 && cnt != type) 659 continue; 660 if (!sb_has_quota_active(sb, cnt)) 661 continue; 662 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, 663 I_MUTEX_QUOTA); 664 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); 665 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); 666 } 667 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 668 669 return 0; 670 } 671 EXPORT_SYMBOL(dquot_quota_sync); 672 673 /* Free unused dquots from cache */ 674 static void prune_dqcache(int count) 675 { 676 struct list_head *head; 677 struct dquot *dquot; 678 679 head = free_dquots.prev; 680 while (head != &free_dquots && count) { 681 dquot = list_entry(head, struct dquot, dq_free); 682 remove_dquot_hash(dquot); 683 remove_free_dquot(dquot); 684 remove_inuse(dquot); 685 do_destroy_dquot(dquot); 686 count--; 687 head = free_dquots.prev; 688 } 689 } 690 691 /* 692 * This is called from kswapd when we think we need some 693 * more memory 694 */ 695 static int shrink_dqcache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) 696 { 697 if (nr) { 698 spin_lock(&dq_list_lock); 699 prune_dqcache(nr); 700 spin_unlock(&dq_list_lock); 701 } 702 return ((unsigned) 703 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS]) 704 /100) * sysctl_vfs_cache_pressure; 705 } 706 707 static struct shrinker dqcache_shrinker = { 708 .shrink = shrink_dqcache_memory, 709 .seeks = DEFAULT_SEEKS, 710 }; 711 712 /* 713 * Put reference to dquot 714 * NOTE: If you change this function please check whether dqput_blocks() works right... 715 */ 716 void dqput(struct dquot *dquot) 717 { 718 int ret; 719 720 if (!dquot) 721 return; 722 #ifdef CONFIG_QUOTA_DEBUG 723 if (!atomic_read(&dquot->dq_count)) { 724 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 725 quotatypes[dquot->dq_type], dquot->dq_id); 726 BUG(); 727 } 728 #endif 729 dqstats_inc(DQST_DROPS); 730 we_slept: 731 spin_lock(&dq_list_lock); 732 if (atomic_read(&dquot->dq_count) > 1) { 733 /* We have more than one user... nothing to do */ 734 atomic_dec(&dquot->dq_count); 735 /* Releasing dquot during quotaoff phase? */ 736 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 737 atomic_read(&dquot->dq_count) == 1) 738 wake_up(&dquot->dq_wait_unused); 739 spin_unlock(&dq_list_lock); 740 return; 741 } 742 /* Need to release dquot? */ 743 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 744 spin_unlock(&dq_list_lock); 745 /* Commit dquot before releasing */ 746 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 747 if (ret < 0) { 748 quota_error(dquot->dq_sb, "Can't write quota structure" 749 " (error %d). Quota may get out of sync!", 750 ret); 751 /* 752 * We clear dirty bit anyway, so that we avoid 753 * infinite loop here 754 */ 755 spin_lock(&dq_list_lock); 756 clear_dquot_dirty(dquot); 757 spin_unlock(&dq_list_lock); 758 } 759 goto we_slept; 760 } 761 /* Clear flag in case dquot was inactive (something bad happened) */ 762 clear_dquot_dirty(dquot); 763 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 764 spin_unlock(&dq_list_lock); 765 dquot->dq_sb->dq_op->release_dquot(dquot); 766 goto we_slept; 767 } 768 atomic_dec(&dquot->dq_count); 769 #ifdef CONFIG_QUOTA_DEBUG 770 /* sanity check */ 771 BUG_ON(!list_empty(&dquot->dq_free)); 772 #endif 773 put_dquot_last(dquot); 774 spin_unlock(&dq_list_lock); 775 } 776 EXPORT_SYMBOL(dqput); 777 778 struct dquot *dquot_alloc(struct super_block *sb, int type) 779 { 780 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 781 } 782 EXPORT_SYMBOL(dquot_alloc); 783 784 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 785 { 786 struct dquot *dquot; 787 788 dquot = sb->dq_op->alloc_dquot(sb, type); 789 if(!dquot) 790 return NULL; 791 792 mutex_init(&dquot->dq_lock); 793 INIT_LIST_HEAD(&dquot->dq_free); 794 INIT_LIST_HEAD(&dquot->dq_inuse); 795 INIT_HLIST_NODE(&dquot->dq_hash); 796 INIT_LIST_HEAD(&dquot->dq_dirty); 797 init_waitqueue_head(&dquot->dq_wait_unused); 798 dquot->dq_sb = sb; 799 dquot->dq_type = type; 800 atomic_set(&dquot->dq_count, 1); 801 802 return dquot; 803 } 804 805 /* 806 * Get reference to dquot 807 * 808 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 809 * destroying our dquot by: 810 * a) checking for quota flags under dq_list_lock and 811 * b) getting a reference to dquot before we release dq_list_lock 812 */ 813 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 814 { 815 unsigned int hashent = hashfn(sb, id, type); 816 struct dquot *dquot = NULL, *empty = NULL; 817 818 if (!sb_has_quota_active(sb, type)) 819 return NULL; 820 we_slept: 821 spin_lock(&dq_list_lock); 822 spin_lock(&dq_state_lock); 823 if (!sb_has_quota_active(sb, type)) { 824 spin_unlock(&dq_state_lock); 825 spin_unlock(&dq_list_lock); 826 goto out; 827 } 828 spin_unlock(&dq_state_lock); 829 830 dquot = find_dquot(hashent, sb, id, type); 831 if (!dquot) { 832 if (!empty) { 833 spin_unlock(&dq_list_lock); 834 empty = get_empty_dquot(sb, type); 835 if (!empty) 836 schedule(); /* Try to wait for a moment... */ 837 goto we_slept; 838 } 839 dquot = empty; 840 empty = NULL; 841 dquot->dq_id = id; 842 /* all dquots go on the inuse_list */ 843 put_inuse(dquot); 844 /* hash it first so it can be found */ 845 insert_dquot_hash(dquot); 846 spin_unlock(&dq_list_lock); 847 dqstats_inc(DQST_LOOKUPS); 848 } else { 849 if (!atomic_read(&dquot->dq_count)) 850 remove_free_dquot(dquot); 851 atomic_inc(&dquot->dq_count); 852 spin_unlock(&dq_list_lock); 853 dqstats_inc(DQST_CACHE_HITS); 854 dqstats_inc(DQST_LOOKUPS); 855 } 856 /* Wait for dq_lock - after this we know that either dquot_release() is 857 * already finished or it will be canceled due to dq_count > 1 test */ 858 wait_on_dquot(dquot); 859 /* Read the dquot / allocate space in quota file */ 860 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 861 sb->dq_op->acquire_dquot(dquot) < 0) { 862 dqput(dquot); 863 dquot = NULL; 864 goto out; 865 } 866 #ifdef CONFIG_QUOTA_DEBUG 867 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 868 #endif 869 out: 870 if (empty) 871 do_destroy_dquot(empty); 872 873 return dquot; 874 } 875 EXPORT_SYMBOL(dqget); 876 877 static int dqinit_needed(struct inode *inode, int type) 878 { 879 int cnt; 880 881 if (IS_NOQUOTA(inode)) 882 return 0; 883 if (type != -1) 884 return !inode->i_dquot[type]; 885 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 886 if (!inode->i_dquot[cnt]) 887 return 1; 888 return 0; 889 } 890 891 /* This routine is guarded by dqonoff_mutex mutex */ 892 static void add_dquot_ref(struct super_block *sb, int type) 893 { 894 struct inode *inode, *old_inode = NULL; 895 #ifdef CONFIG_QUOTA_DEBUG 896 int reserved = 0; 897 #endif 898 899 spin_lock(&inode_lock); 900 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 901 if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) 902 continue; 903 #ifdef CONFIG_QUOTA_DEBUG 904 if (unlikely(inode_get_rsv_space(inode) > 0)) 905 reserved = 1; 906 #endif 907 if (!atomic_read(&inode->i_writecount)) 908 continue; 909 if (!dqinit_needed(inode, type)) 910 continue; 911 912 __iget(inode); 913 spin_unlock(&inode_lock); 914 915 iput(old_inode); 916 __dquot_initialize(inode, type); 917 /* We hold a reference to 'inode' so it couldn't have been 918 * removed from s_inodes list while we dropped the inode_lock. 919 * We cannot iput the inode now as we can be holding the last 920 * reference and we cannot iput it under inode_lock. So we 921 * keep the reference and iput it later. */ 922 old_inode = inode; 923 spin_lock(&inode_lock); 924 } 925 spin_unlock(&inode_lock); 926 iput(old_inode); 927 928 #ifdef CONFIG_QUOTA_DEBUG 929 if (reserved) { 930 quota_error(sb, "Writes happened before quota was turned on " 931 "thus quota information is probably inconsistent. " 932 "Please run quotacheck(8)"); 933 } 934 #endif 935 } 936 937 /* 938 * Return 0 if dqput() won't block. 939 * (note that 1 doesn't necessarily mean blocking) 940 */ 941 static inline int dqput_blocks(struct dquot *dquot) 942 { 943 if (atomic_read(&dquot->dq_count) <= 1) 944 return 1; 945 return 0; 946 } 947 948 /* 949 * Remove references to dquots from inode and add dquot to list for freeing 950 * if we have the last referece to dquot 951 * We can't race with anybody because we hold dqptr_sem for writing... 952 */ 953 static int remove_inode_dquot_ref(struct inode *inode, int type, 954 struct list_head *tofree_head) 955 { 956 struct dquot *dquot = inode->i_dquot[type]; 957 958 inode->i_dquot[type] = NULL; 959 if (dquot) { 960 if (dqput_blocks(dquot)) { 961 #ifdef CONFIG_QUOTA_DEBUG 962 if (atomic_read(&dquot->dq_count) != 1) 963 quota_error(inode->i_sb, "Adding dquot with " 964 "dq_count %d to dispose list", 965 atomic_read(&dquot->dq_count)); 966 #endif 967 spin_lock(&dq_list_lock); 968 /* As dquot must have currently users it can't be on 969 * the free list... */ 970 list_add(&dquot->dq_free, tofree_head); 971 spin_unlock(&dq_list_lock); 972 return 1; 973 } 974 else 975 dqput(dquot); /* We have guaranteed we won't block */ 976 } 977 return 0; 978 } 979 980 /* 981 * Free list of dquots 982 * Dquots are removed from inodes and no new references can be got so we are 983 * the only ones holding reference 984 */ 985 static void put_dquot_list(struct list_head *tofree_head) 986 { 987 struct list_head *act_head; 988 struct dquot *dquot; 989 990 act_head = tofree_head->next; 991 while (act_head != tofree_head) { 992 dquot = list_entry(act_head, struct dquot, dq_free); 993 act_head = act_head->next; 994 /* Remove dquot from the list so we won't have problems... */ 995 list_del_init(&dquot->dq_free); 996 dqput(dquot); 997 } 998 } 999 1000 static void remove_dquot_ref(struct super_block *sb, int type, 1001 struct list_head *tofree_head) 1002 { 1003 struct inode *inode; 1004 int reserved = 0; 1005 1006 spin_lock(&inode_lock); 1007 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1008 /* 1009 * We have to scan also I_NEW inodes because they can already 1010 * have quota pointer initialized. Luckily, we need to touch 1011 * only quota pointers and these have separate locking 1012 * (dqptr_sem). 1013 */ 1014 if (!IS_NOQUOTA(inode)) { 1015 if (unlikely(inode_get_rsv_space(inode) > 0)) 1016 reserved = 1; 1017 remove_inode_dquot_ref(inode, type, tofree_head); 1018 } 1019 } 1020 spin_unlock(&inode_lock); 1021 #ifdef CONFIG_QUOTA_DEBUG 1022 if (reserved) { 1023 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1024 " was disabled thus quota information is probably " 1025 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1026 } 1027 #endif 1028 } 1029 1030 /* Gather all references from inodes and drop them */ 1031 static void drop_dquot_ref(struct super_block *sb, int type) 1032 { 1033 LIST_HEAD(tofree_head); 1034 1035 if (sb->dq_op) { 1036 down_write(&sb_dqopt(sb)->dqptr_sem); 1037 remove_dquot_ref(sb, type, &tofree_head); 1038 up_write(&sb_dqopt(sb)->dqptr_sem); 1039 put_dquot_list(&tofree_head); 1040 } 1041 } 1042 1043 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1044 { 1045 dquot->dq_dqb.dqb_curinodes += number; 1046 } 1047 1048 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1049 { 1050 dquot->dq_dqb.dqb_curspace += number; 1051 } 1052 1053 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1054 { 1055 dquot->dq_dqb.dqb_rsvspace += number; 1056 } 1057 1058 /* 1059 * Claim reserved quota space 1060 */ 1061 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1062 { 1063 if (dquot->dq_dqb.dqb_rsvspace < number) { 1064 WARN_ON_ONCE(1); 1065 number = dquot->dq_dqb.dqb_rsvspace; 1066 } 1067 dquot->dq_dqb.dqb_curspace += number; 1068 dquot->dq_dqb.dqb_rsvspace -= number; 1069 } 1070 1071 static inline 1072 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1073 { 1074 if (dquot->dq_dqb.dqb_rsvspace >= number) 1075 dquot->dq_dqb.dqb_rsvspace -= number; 1076 else { 1077 WARN_ON_ONCE(1); 1078 dquot->dq_dqb.dqb_rsvspace = 0; 1079 } 1080 } 1081 1082 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1083 { 1084 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1085 dquot->dq_dqb.dqb_curinodes >= number) 1086 dquot->dq_dqb.dqb_curinodes -= number; 1087 else 1088 dquot->dq_dqb.dqb_curinodes = 0; 1089 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1090 dquot->dq_dqb.dqb_itime = (time_t) 0; 1091 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1092 } 1093 1094 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1095 { 1096 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1097 dquot->dq_dqb.dqb_curspace >= number) 1098 dquot->dq_dqb.dqb_curspace -= number; 1099 else 1100 dquot->dq_dqb.dqb_curspace = 0; 1101 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1102 dquot->dq_dqb.dqb_btime = (time_t) 0; 1103 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1104 } 1105 1106 static int warning_issued(struct dquot *dquot, const int warntype) 1107 { 1108 int flag = (warntype == QUOTA_NL_BHARDWARN || 1109 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1110 ((warntype == QUOTA_NL_IHARDWARN || 1111 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1112 1113 if (!flag) 1114 return 0; 1115 return test_and_set_bit(flag, &dquot->dq_flags); 1116 } 1117 1118 #ifdef CONFIG_PRINT_QUOTA_WARNING 1119 static int flag_print_warnings = 1; 1120 1121 static int need_print_warning(struct dquot *dquot) 1122 { 1123 if (!flag_print_warnings) 1124 return 0; 1125 1126 switch (dquot->dq_type) { 1127 case USRQUOTA: 1128 return current_fsuid() == dquot->dq_id; 1129 case GRPQUOTA: 1130 return in_group_p(dquot->dq_id); 1131 } 1132 return 0; 1133 } 1134 1135 /* Print warning to user which exceeded quota */ 1136 static void print_warning(struct dquot *dquot, const int warntype) 1137 { 1138 char *msg = NULL; 1139 struct tty_struct *tty; 1140 1141 if (warntype == QUOTA_NL_IHARDBELOW || 1142 warntype == QUOTA_NL_ISOFTBELOW || 1143 warntype == QUOTA_NL_BHARDBELOW || 1144 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1145 return; 1146 1147 tty = get_current_tty(); 1148 if (!tty) 1149 return; 1150 tty_write_message(tty, dquot->dq_sb->s_id); 1151 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1152 tty_write_message(tty, ": warning, "); 1153 else 1154 tty_write_message(tty, ": write failed, "); 1155 tty_write_message(tty, quotatypes[dquot->dq_type]); 1156 switch (warntype) { 1157 case QUOTA_NL_IHARDWARN: 1158 msg = " file limit reached.\r\n"; 1159 break; 1160 case QUOTA_NL_ISOFTLONGWARN: 1161 msg = " file quota exceeded too long.\r\n"; 1162 break; 1163 case QUOTA_NL_ISOFTWARN: 1164 msg = " file quota exceeded.\r\n"; 1165 break; 1166 case QUOTA_NL_BHARDWARN: 1167 msg = " block limit reached.\r\n"; 1168 break; 1169 case QUOTA_NL_BSOFTLONGWARN: 1170 msg = " block quota exceeded too long.\r\n"; 1171 break; 1172 case QUOTA_NL_BSOFTWARN: 1173 msg = " block quota exceeded.\r\n"; 1174 break; 1175 } 1176 tty_write_message(tty, msg); 1177 tty_kref_put(tty); 1178 } 1179 #endif 1180 1181 /* 1182 * Write warnings to the console and send warning messages over netlink. 1183 * 1184 * Note that this function can sleep. 1185 */ 1186 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1187 { 1188 struct dquot *dq; 1189 int i; 1190 1191 for (i = 0; i < MAXQUOTAS; i++) { 1192 dq = dquots[i]; 1193 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1194 !warning_issued(dq, warntype[i])) { 1195 #ifdef CONFIG_PRINT_QUOTA_WARNING 1196 print_warning(dq, warntype[i]); 1197 #endif 1198 quota_send_warning(dq->dq_type, dq->dq_id, 1199 dq->dq_sb->s_dev, warntype[i]); 1200 } 1201 } 1202 } 1203 1204 static int ignore_hardlimit(struct dquot *dquot) 1205 { 1206 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1207 1208 return capable(CAP_SYS_RESOURCE) && 1209 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1210 !(info->dqi_flags & V1_DQF_RSQUASH)); 1211 } 1212 1213 /* needs dq_data_lock */ 1214 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1215 { 1216 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1217 1218 *warntype = QUOTA_NL_NOWARN; 1219 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1220 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1221 return 0; 1222 1223 if (dquot->dq_dqb.dqb_ihardlimit && 1224 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1225 !ignore_hardlimit(dquot)) { 1226 *warntype = QUOTA_NL_IHARDWARN; 1227 return -EDQUOT; 1228 } 1229 1230 if (dquot->dq_dqb.dqb_isoftlimit && 1231 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1232 dquot->dq_dqb.dqb_itime && 1233 get_seconds() >= dquot->dq_dqb.dqb_itime && 1234 !ignore_hardlimit(dquot)) { 1235 *warntype = QUOTA_NL_ISOFTLONGWARN; 1236 return -EDQUOT; 1237 } 1238 1239 if (dquot->dq_dqb.dqb_isoftlimit && 1240 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1241 dquot->dq_dqb.dqb_itime == 0) { 1242 *warntype = QUOTA_NL_ISOFTWARN; 1243 dquot->dq_dqb.dqb_itime = get_seconds() + 1244 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1245 } 1246 1247 return 0; 1248 } 1249 1250 /* needs dq_data_lock */ 1251 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1252 { 1253 qsize_t tspace; 1254 struct super_block *sb = dquot->dq_sb; 1255 1256 *warntype = QUOTA_NL_NOWARN; 1257 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1258 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1259 return 0; 1260 1261 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1262 + space; 1263 1264 if (dquot->dq_dqb.dqb_bhardlimit && 1265 tspace > dquot->dq_dqb.dqb_bhardlimit && 1266 !ignore_hardlimit(dquot)) { 1267 if (!prealloc) 1268 *warntype = QUOTA_NL_BHARDWARN; 1269 return -EDQUOT; 1270 } 1271 1272 if (dquot->dq_dqb.dqb_bsoftlimit && 1273 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1274 dquot->dq_dqb.dqb_btime && 1275 get_seconds() >= dquot->dq_dqb.dqb_btime && 1276 !ignore_hardlimit(dquot)) { 1277 if (!prealloc) 1278 *warntype = QUOTA_NL_BSOFTLONGWARN; 1279 return -EDQUOT; 1280 } 1281 1282 if (dquot->dq_dqb.dqb_bsoftlimit && 1283 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1284 dquot->dq_dqb.dqb_btime == 0) { 1285 if (!prealloc) { 1286 *warntype = QUOTA_NL_BSOFTWARN; 1287 dquot->dq_dqb.dqb_btime = get_seconds() + 1288 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1289 } 1290 else 1291 /* 1292 * We don't allow preallocation to exceed softlimit so exceeding will 1293 * be always printed 1294 */ 1295 return -EDQUOT; 1296 } 1297 1298 return 0; 1299 } 1300 1301 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1302 { 1303 qsize_t newinodes; 1304 1305 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1306 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1307 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1308 return QUOTA_NL_NOWARN; 1309 1310 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1311 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1312 return QUOTA_NL_ISOFTBELOW; 1313 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1314 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1315 return QUOTA_NL_IHARDBELOW; 1316 return QUOTA_NL_NOWARN; 1317 } 1318 1319 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1320 { 1321 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1322 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1323 return QUOTA_NL_NOWARN; 1324 1325 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1326 return QUOTA_NL_BSOFTBELOW; 1327 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1328 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1329 return QUOTA_NL_BHARDBELOW; 1330 return QUOTA_NL_NOWARN; 1331 } 1332 1333 static int dquot_active(const struct inode *inode) 1334 { 1335 struct super_block *sb = inode->i_sb; 1336 1337 if (IS_NOQUOTA(inode)) 1338 return 0; 1339 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1340 } 1341 1342 /* 1343 * Initialize quota pointers in inode 1344 * 1345 * We do things in a bit complicated way but by that we avoid calling 1346 * dqget() and thus filesystem callbacks under dqptr_sem. 1347 * 1348 * It is better to call this function outside of any transaction as it 1349 * might need a lot of space in journal for dquot structure allocation. 1350 */ 1351 static void __dquot_initialize(struct inode *inode, int type) 1352 { 1353 unsigned int id = 0; 1354 int cnt; 1355 struct dquot *got[MAXQUOTAS]; 1356 struct super_block *sb = inode->i_sb; 1357 qsize_t rsv; 1358 1359 /* First test before acquiring mutex - solves deadlocks when we 1360 * re-enter the quota code and are already holding the mutex */ 1361 if (!dquot_active(inode)) 1362 return; 1363 1364 /* First get references to structures we might need. */ 1365 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1366 got[cnt] = NULL; 1367 if (type != -1 && cnt != type) 1368 continue; 1369 switch (cnt) { 1370 case USRQUOTA: 1371 id = inode->i_uid; 1372 break; 1373 case GRPQUOTA: 1374 id = inode->i_gid; 1375 break; 1376 } 1377 got[cnt] = dqget(sb, id, cnt); 1378 } 1379 1380 down_write(&sb_dqopt(sb)->dqptr_sem); 1381 if (IS_NOQUOTA(inode)) 1382 goto out_err; 1383 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1384 if (type != -1 && cnt != type) 1385 continue; 1386 /* Avoid races with quotaoff() */ 1387 if (!sb_has_quota_active(sb, cnt)) 1388 continue; 1389 /* We could race with quotaon or dqget() could have failed */ 1390 if (!got[cnt]) 1391 continue; 1392 if (!inode->i_dquot[cnt]) { 1393 inode->i_dquot[cnt] = got[cnt]; 1394 got[cnt] = NULL; 1395 /* 1396 * Make quota reservation system happy if someone 1397 * did a write before quota was turned on 1398 */ 1399 rsv = inode_get_rsv_space(inode); 1400 if (unlikely(rsv)) 1401 dquot_resv_space(inode->i_dquot[cnt], rsv); 1402 } 1403 } 1404 out_err: 1405 up_write(&sb_dqopt(sb)->dqptr_sem); 1406 /* Drop unused references */ 1407 dqput_all(got); 1408 } 1409 1410 void dquot_initialize(struct inode *inode) 1411 { 1412 __dquot_initialize(inode, -1); 1413 } 1414 EXPORT_SYMBOL(dquot_initialize); 1415 1416 /* 1417 * Release all quotas referenced by inode 1418 */ 1419 static void __dquot_drop(struct inode *inode) 1420 { 1421 int cnt; 1422 struct dquot *put[MAXQUOTAS]; 1423 1424 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1425 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1426 put[cnt] = inode->i_dquot[cnt]; 1427 inode->i_dquot[cnt] = NULL; 1428 } 1429 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1430 dqput_all(put); 1431 } 1432 1433 void dquot_drop(struct inode *inode) 1434 { 1435 int cnt; 1436 1437 if (IS_NOQUOTA(inode)) 1438 return; 1439 1440 /* 1441 * Test before calling to rule out calls from proc and such 1442 * where we are not allowed to block. Note that this is 1443 * actually reliable test even without the lock - the caller 1444 * must assure that nobody can come after the DQUOT_DROP and 1445 * add quota pointers back anyway. 1446 */ 1447 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1448 if (inode->i_dquot[cnt]) 1449 break; 1450 } 1451 1452 if (cnt < MAXQUOTAS) 1453 __dquot_drop(inode); 1454 } 1455 EXPORT_SYMBOL(dquot_drop); 1456 1457 /* 1458 * inode_reserved_space is managed internally by quota, and protected by 1459 * i_lock similar to i_blocks+i_bytes. 1460 */ 1461 static qsize_t *inode_reserved_space(struct inode * inode) 1462 { 1463 /* Filesystem must explicitly define it's own method in order to use 1464 * quota reservation interface */ 1465 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1466 return inode->i_sb->dq_op->get_reserved_space(inode); 1467 } 1468 1469 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1470 { 1471 spin_lock(&inode->i_lock); 1472 *inode_reserved_space(inode) += number; 1473 spin_unlock(&inode->i_lock); 1474 } 1475 EXPORT_SYMBOL(inode_add_rsv_space); 1476 1477 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1478 { 1479 spin_lock(&inode->i_lock); 1480 *inode_reserved_space(inode) -= number; 1481 __inode_add_bytes(inode, number); 1482 spin_unlock(&inode->i_lock); 1483 } 1484 EXPORT_SYMBOL(inode_claim_rsv_space); 1485 1486 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1487 { 1488 spin_lock(&inode->i_lock); 1489 *inode_reserved_space(inode) -= number; 1490 spin_unlock(&inode->i_lock); 1491 } 1492 EXPORT_SYMBOL(inode_sub_rsv_space); 1493 1494 static qsize_t inode_get_rsv_space(struct inode *inode) 1495 { 1496 qsize_t ret; 1497 1498 if (!inode->i_sb->dq_op->get_reserved_space) 1499 return 0; 1500 spin_lock(&inode->i_lock); 1501 ret = *inode_reserved_space(inode); 1502 spin_unlock(&inode->i_lock); 1503 return ret; 1504 } 1505 1506 static void inode_incr_space(struct inode *inode, qsize_t number, 1507 int reserve) 1508 { 1509 if (reserve) 1510 inode_add_rsv_space(inode, number); 1511 else 1512 inode_add_bytes(inode, number); 1513 } 1514 1515 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1516 { 1517 if (reserve) 1518 inode_sub_rsv_space(inode, number); 1519 else 1520 inode_sub_bytes(inode, number); 1521 } 1522 1523 /* 1524 * This functions updates i_blocks+i_bytes fields and quota information 1525 * (together with appropriate checks). 1526 * 1527 * NOTE: We absolutely rely on the fact that caller dirties the inode 1528 * (usually helpers in quotaops.h care about this) and holds a handle for 1529 * the current transaction so that dquot write and inode write go into the 1530 * same transaction. 1531 */ 1532 1533 /* 1534 * This operation can block, but only after everything is updated 1535 */ 1536 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1537 { 1538 int cnt, ret = 0; 1539 char warntype[MAXQUOTAS]; 1540 int warn = flags & DQUOT_SPACE_WARN; 1541 int reserve = flags & DQUOT_SPACE_RESERVE; 1542 int nofail = flags & DQUOT_SPACE_NOFAIL; 1543 1544 /* 1545 * First test before acquiring mutex - solves deadlocks when we 1546 * re-enter the quota code and are already holding the mutex 1547 */ 1548 if (!dquot_active(inode)) { 1549 inode_incr_space(inode, number, reserve); 1550 goto out; 1551 } 1552 1553 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1554 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1555 warntype[cnt] = QUOTA_NL_NOWARN; 1556 1557 spin_lock(&dq_data_lock); 1558 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1559 if (!inode->i_dquot[cnt]) 1560 continue; 1561 ret = check_bdq(inode->i_dquot[cnt], number, !warn, 1562 warntype+cnt); 1563 if (ret && !nofail) { 1564 spin_unlock(&dq_data_lock); 1565 goto out_flush_warn; 1566 } 1567 } 1568 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1569 if (!inode->i_dquot[cnt]) 1570 continue; 1571 if (reserve) 1572 dquot_resv_space(inode->i_dquot[cnt], number); 1573 else 1574 dquot_incr_space(inode->i_dquot[cnt], number); 1575 } 1576 inode_incr_space(inode, number, reserve); 1577 spin_unlock(&dq_data_lock); 1578 1579 if (reserve) 1580 goto out_flush_warn; 1581 mark_all_dquot_dirty(inode->i_dquot); 1582 out_flush_warn: 1583 flush_warnings(inode->i_dquot, warntype); 1584 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1585 out: 1586 return ret; 1587 } 1588 EXPORT_SYMBOL(__dquot_alloc_space); 1589 1590 /* 1591 * This operation can block, but only after everything is updated 1592 */ 1593 int dquot_alloc_inode(const struct inode *inode) 1594 { 1595 int cnt, ret = 0; 1596 char warntype[MAXQUOTAS]; 1597 1598 /* First test before acquiring mutex - solves deadlocks when we 1599 * re-enter the quota code and are already holding the mutex */ 1600 if (!dquot_active(inode)) 1601 return 0; 1602 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1603 warntype[cnt] = QUOTA_NL_NOWARN; 1604 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1605 spin_lock(&dq_data_lock); 1606 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1607 if (!inode->i_dquot[cnt]) 1608 continue; 1609 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt); 1610 if (ret) 1611 goto warn_put_all; 1612 } 1613 1614 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1615 if (!inode->i_dquot[cnt]) 1616 continue; 1617 dquot_incr_inodes(inode->i_dquot[cnt], 1); 1618 } 1619 1620 warn_put_all: 1621 spin_unlock(&dq_data_lock); 1622 if (ret == 0) 1623 mark_all_dquot_dirty(inode->i_dquot); 1624 flush_warnings(inode->i_dquot, warntype); 1625 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1626 return ret; 1627 } 1628 EXPORT_SYMBOL(dquot_alloc_inode); 1629 1630 /* 1631 * Convert in-memory reserved quotas to real consumed quotas 1632 */ 1633 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1634 { 1635 int cnt; 1636 1637 if (!dquot_active(inode)) { 1638 inode_claim_rsv_space(inode, number); 1639 return 0; 1640 } 1641 1642 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1643 spin_lock(&dq_data_lock); 1644 /* Claim reserved quotas to allocated quotas */ 1645 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1646 if (inode->i_dquot[cnt]) 1647 dquot_claim_reserved_space(inode->i_dquot[cnt], 1648 number); 1649 } 1650 /* Update inode bytes */ 1651 inode_claim_rsv_space(inode, number); 1652 spin_unlock(&dq_data_lock); 1653 mark_all_dquot_dirty(inode->i_dquot); 1654 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1655 return 0; 1656 } 1657 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1658 1659 /* 1660 * This operation can block, but only after everything is updated 1661 */ 1662 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1663 { 1664 unsigned int cnt; 1665 char warntype[MAXQUOTAS]; 1666 int reserve = flags & DQUOT_SPACE_RESERVE; 1667 1668 /* First test before acquiring mutex - solves deadlocks when we 1669 * re-enter the quota code and are already holding the mutex */ 1670 if (!dquot_active(inode)) { 1671 inode_decr_space(inode, number, reserve); 1672 return; 1673 } 1674 1675 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1676 spin_lock(&dq_data_lock); 1677 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1678 if (!inode->i_dquot[cnt]) 1679 continue; 1680 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1681 if (reserve) 1682 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1683 else 1684 dquot_decr_space(inode->i_dquot[cnt], number); 1685 } 1686 inode_decr_space(inode, number, reserve); 1687 spin_unlock(&dq_data_lock); 1688 1689 if (reserve) 1690 goto out_unlock; 1691 mark_all_dquot_dirty(inode->i_dquot); 1692 out_unlock: 1693 flush_warnings(inode->i_dquot, warntype); 1694 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1695 } 1696 EXPORT_SYMBOL(__dquot_free_space); 1697 1698 /* 1699 * This operation can block, but only after everything is updated 1700 */ 1701 void dquot_free_inode(const struct inode *inode) 1702 { 1703 unsigned int cnt; 1704 char warntype[MAXQUOTAS]; 1705 1706 /* First test before acquiring mutex - solves deadlocks when we 1707 * re-enter the quota code and are already holding the mutex */ 1708 if (!dquot_active(inode)) 1709 return; 1710 1711 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1712 spin_lock(&dq_data_lock); 1713 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1714 if (!inode->i_dquot[cnt]) 1715 continue; 1716 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1); 1717 dquot_decr_inodes(inode->i_dquot[cnt], 1); 1718 } 1719 spin_unlock(&dq_data_lock); 1720 mark_all_dquot_dirty(inode->i_dquot); 1721 flush_warnings(inode->i_dquot, warntype); 1722 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1723 } 1724 EXPORT_SYMBOL(dquot_free_inode); 1725 1726 /* 1727 * Transfer the number of inode and blocks from one diskquota to an other. 1728 * On success, dquot references in transfer_to are consumed and references 1729 * to original dquots that need to be released are placed there. On failure, 1730 * references are kept untouched. 1731 * 1732 * This operation can block, but only after everything is updated 1733 * A transaction must be started when entering this function. 1734 * 1735 */ 1736 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1737 { 1738 qsize_t space, cur_space; 1739 qsize_t rsv_space = 0; 1740 struct dquot *transfer_from[MAXQUOTAS] = {}; 1741 int cnt, ret = 0; 1742 char is_valid[MAXQUOTAS] = {}; 1743 char warntype_to[MAXQUOTAS]; 1744 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1745 1746 /* First test before acquiring mutex - solves deadlocks when we 1747 * re-enter the quota code and are already holding the mutex */ 1748 if (IS_NOQUOTA(inode)) 1749 return 0; 1750 /* Initialize the arrays */ 1751 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1752 warntype_to[cnt] = QUOTA_NL_NOWARN; 1753 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1754 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1755 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1756 return 0; 1757 } 1758 spin_lock(&dq_data_lock); 1759 cur_space = inode_get_bytes(inode); 1760 rsv_space = inode_get_rsv_space(inode); 1761 space = cur_space + rsv_space; 1762 /* Build the transfer_from list and check the limits */ 1763 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1764 /* 1765 * Skip changes for same uid or gid or for turned off quota-type. 1766 */ 1767 if (!transfer_to[cnt]) 1768 continue; 1769 /* Avoid races with quotaoff() */ 1770 if (!sb_has_quota_active(inode->i_sb, cnt)) 1771 continue; 1772 is_valid[cnt] = 1; 1773 transfer_from[cnt] = inode->i_dquot[cnt]; 1774 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt); 1775 if (ret) 1776 goto over_quota; 1777 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt); 1778 if (ret) 1779 goto over_quota; 1780 } 1781 1782 /* 1783 * Finally perform the needed transfer from transfer_from to transfer_to 1784 */ 1785 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1786 if (!is_valid[cnt]) 1787 continue; 1788 /* Due to IO error we might not have transfer_from[] structure */ 1789 if (transfer_from[cnt]) { 1790 warntype_from_inodes[cnt] = 1791 info_idq_free(transfer_from[cnt], 1); 1792 warntype_from_space[cnt] = 1793 info_bdq_free(transfer_from[cnt], space); 1794 dquot_decr_inodes(transfer_from[cnt], 1); 1795 dquot_decr_space(transfer_from[cnt], cur_space); 1796 dquot_free_reserved_space(transfer_from[cnt], 1797 rsv_space); 1798 } 1799 1800 dquot_incr_inodes(transfer_to[cnt], 1); 1801 dquot_incr_space(transfer_to[cnt], cur_space); 1802 dquot_resv_space(transfer_to[cnt], rsv_space); 1803 1804 inode->i_dquot[cnt] = transfer_to[cnt]; 1805 } 1806 spin_unlock(&dq_data_lock); 1807 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1808 1809 mark_all_dquot_dirty(transfer_from); 1810 mark_all_dquot_dirty(transfer_to); 1811 flush_warnings(transfer_to, warntype_to); 1812 flush_warnings(transfer_from, warntype_from_inodes); 1813 flush_warnings(transfer_from, warntype_from_space); 1814 /* Pass back references to put */ 1815 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1816 if (is_valid[cnt]) 1817 transfer_to[cnt] = transfer_from[cnt]; 1818 return 0; 1819 over_quota: 1820 spin_unlock(&dq_data_lock); 1821 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1822 flush_warnings(transfer_to, warntype_to); 1823 return ret; 1824 } 1825 EXPORT_SYMBOL(__dquot_transfer); 1826 1827 /* Wrapper for transferring ownership of an inode for uid/gid only 1828 * Called from FSXXX_setattr() 1829 */ 1830 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1831 { 1832 struct dquot *transfer_to[MAXQUOTAS] = {}; 1833 struct super_block *sb = inode->i_sb; 1834 int ret; 1835 1836 if (!dquot_active(inode)) 1837 return 0; 1838 1839 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) 1840 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA); 1841 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) 1842 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA); 1843 1844 ret = __dquot_transfer(inode, transfer_to); 1845 dqput_all(transfer_to); 1846 return ret; 1847 } 1848 EXPORT_SYMBOL(dquot_transfer); 1849 1850 /* 1851 * Write info of quota file to disk 1852 */ 1853 int dquot_commit_info(struct super_block *sb, int type) 1854 { 1855 int ret; 1856 struct quota_info *dqopt = sb_dqopt(sb); 1857 1858 mutex_lock(&dqopt->dqio_mutex); 1859 ret = dqopt->ops[type]->write_file_info(sb, type); 1860 mutex_unlock(&dqopt->dqio_mutex); 1861 return ret; 1862 } 1863 EXPORT_SYMBOL(dquot_commit_info); 1864 1865 /* 1866 * Definitions of diskquota operations. 1867 */ 1868 const struct dquot_operations dquot_operations = { 1869 .write_dquot = dquot_commit, 1870 .acquire_dquot = dquot_acquire, 1871 .release_dquot = dquot_release, 1872 .mark_dirty = dquot_mark_dquot_dirty, 1873 .write_info = dquot_commit_info, 1874 .alloc_dquot = dquot_alloc, 1875 .destroy_dquot = dquot_destroy, 1876 }; 1877 EXPORT_SYMBOL(dquot_operations); 1878 1879 /* 1880 * Generic helper for ->open on filesystems supporting disk quotas. 1881 */ 1882 int dquot_file_open(struct inode *inode, struct file *file) 1883 { 1884 int error; 1885 1886 error = generic_file_open(inode, file); 1887 if (!error && (file->f_mode & FMODE_WRITE)) 1888 dquot_initialize(inode); 1889 return error; 1890 } 1891 EXPORT_SYMBOL(dquot_file_open); 1892 1893 /* 1894 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1895 */ 1896 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 1897 { 1898 int cnt, ret = 0; 1899 struct quota_info *dqopt = sb_dqopt(sb); 1900 struct inode *toputinode[MAXQUOTAS]; 1901 1902 /* Cannot turn off usage accounting without turning off limits, or 1903 * suspend quotas and simultaneously turn quotas off. */ 1904 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1905 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1906 DQUOT_USAGE_ENABLED))) 1907 return -EINVAL; 1908 1909 /* We need to serialize quota_off() for device */ 1910 mutex_lock(&dqopt->dqonoff_mutex); 1911 1912 /* 1913 * Skip everything if there's nothing to do. We have to do this because 1914 * sometimes we are called when fill_super() failed and calling 1915 * sync_fs() in such cases does no good. 1916 */ 1917 if (!sb_any_quota_loaded(sb)) { 1918 mutex_unlock(&dqopt->dqonoff_mutex); 1919 return 0; 1920 } 1921 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1922 toputinode[cnt] = NULL; 1923 if (type != -1 && cnt != type) 1924 continue; 1925 if (!sb_has_quota_loaded(sb, cnt)) 1926 continue; 1927 1928 if (flags & DQUOT_SUSPENDED) { 1929 spin_lock(&dq_state_lock); 1930 dqopt->flags |= 1931 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1932 spin_unlock(&dq_state_lock); 1933 } else { 1934 spin_lock(&dq_state_lock); 1935 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1936 /* Turning off suspended quotas? */ 1937 if (!sb_has_quota_loaded(sb, cnt) && 1938 sb_has_quota_suspended(sb, cnt)) { 1939 dqopt->flags &= ~dquot_state_flag( 1940 DQUOT_SUSPENDED, cnt); 1941 spin_unlock(&dq_state_lock); 1942 iput(dqopt->files[cnt]); 1943 dqopt->files[cnt] = NULL; 1944 continue; 1945 } 1946 spin_unlock(&dq_state_lock); 1947 } 1948 1949 /* We still have to keep quota loaded? */ 1950 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1951 continue; 1952 1953 /* Note: these are blocking operations */ 1954 drop_dquot_ref(sb, cnt); 1955 invalidate_dquots(sb, cnt); 1956 /* 1957 * Now all dquots should be invalidated, all writes done so we 1958 * should be only users of the info. No locks needed. 1959 */ 1960 if (info_dirty(&dqopt->info[cnt])) 1961 sb->dq_op->write_info(sb, cnt); 1962 if (dqopt->ops[cnt]->free_file_info) 1963 dqopt->ops[cnt]->free_file_info(sb, cnt); 1964 put_quota_format(dqopt->info[cnt].dqi_format); 1965 1966 toputinode[cnt] = dqopt->files[cnt]; 1967 if (!sb_has_quota_loaded(sb, cnt)) 1968 dqopt->files[cnt] = NULL; 1969 dqopt->info[cnt].dqi_flags = 0; 1970 dqopt->info[cnt].dqi_igrace = 0; 1971 dqopt->info[cnt].dqi_bgrace = 0; 1972 dqopt->ops[cnt] = NULL; 1973 } 1974 mutex_unlock(&dqopt->dqonoff_mutex); 1975 1976 /* Skip syncing and setting flags if quota files are hidden */ 1977 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1978 goto put_inodes; 1979 1980 /* Sync the superblock so that buffers with quota data are written to 1981 * disk (and so userspace sees correct data afterwards). */ 1982 if (sb->s_op->sync_fs) 1983 sb->s_op->sync_fs(sb, 1); 1984 sync_blockdev(sb->s_bdev); 1985 /* Now the quota files are just ordinary files and we can set the 1986 * inode flags back. Moreover we discard the pagecache so that 1987 * userspace sees the writes we did bypassing the pagecache. We 1988 * must also discard the blockdev buffers so that we see the 1989 * changes done by userspace on the next quotaon() */ 1990 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1991 if (toputinode[cnt]) { 1992 mutex_lock(&dqopt->dqonoff_mutex); 1993 /* If quota was reenabled in the meantime, we have 1994 * nothing to do */ 1995 if (!sb_has_quota_loaded(sb, cnt)) { 1996 mutex_lock_nested(&toputinode[cnt]->i_mutex, 1997 I_MUTEX_QUOTA); 1998 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1999 S_NOATIME | S_NOQUOTA); 2000 truncate_inode_pages(&toputinode[cnt]->i_data, 2001 0); 2002 mutex_unlock(&toputinode[cnt]->i_mutex); 2003 mark_inode_dirty_sync(toputinode[cnt]); 2004 } 2005 mutex_unlock(&dqopt->dqonoff_mutex); 2006 } 2007 if (sb->s_bdev) 2008 invalidate_bdev(sb->s_bdev); 2009 put_inodes: 2010 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2011 if (toputinode[cnt]) { 2012 /* On remount RO, we keep the inode pointer so that we 2013 * can reenable quota on the subsequent remount RW. We 2014 * have to check 'flags' variable and not use sb_has_ 2015 * function because another quotaon / quotaoff could 2016 * change global state before we got here. We refuse 2017 * to suspend quotas when there is pending delete on 2018 * the quota file... */ 2019 if (!(flags & DQUOT_SUSPENDED)) 2020 iput(toputinode[cnt]); 2021 else if (!toputinode[cnt]->i_nlink) 2022 ret = -EBUSY; 2023 } 2024 return ret; 2025 } 2026 EXPORT_SYMBOL(dquot_disable); 2027 2028 int dquot_quota_off(struct super_block *sb, int type) 2029 { 2030 return dquot_disable(sb, type, 2031 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2032 } 2033 EXPORT_SYMBOL(dquot_quota_off); 2034 2035 /* 2036 * Turn quotas on on a device 2037 */ 2038 2039 /* 2040 * Helper function to turn quotas on when we already have the inode of 2041 * quota file and no quota information is loaded. 2042 */ 2043 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2044 unsigned int flags) 2045 { 2046 struct quota_format_type *fmt = find_quota_format(format_id); 2047 struct super_block *sb = inode->i_sb; 2048 struct quota_info *dqopt = sb_dqopt(sb); 2049 int error; 2050 int oldflags = -1; 2051 2052 if (!fmt) 2053 return -ESRCH; 2054 if (!S_ISREG(inode->i_mode)) { 2055 error = -EACCES; 2056 goto out_fmt; 2057 } 2058 if (IS_RDONLY(inode)) { 2059 error = -EROFS; 2060 goto out_fmt; 2061 } 2062 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 2063 error = -EINVAL; 2064 goto out_fmt; 2065 } 2066 /* Usage always has to be set... */ 2067 if (!(flags & DQUOT_USAGE_ENABLED)) { 2068 error = -EINVAL; 2069 goto out_fmt; 2070 } 2071 2072 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2073 /* As we bypass the pagecache we must now flush all the 2074 * dirty data and invalidate caches so that kernel sees 2075 * changes from userspace. It is not enough to just flush 2076 * the quota file since if blocksize < pagesize, invalidation 2077 * of the cache could fail because of other unrelated dirty 2078 * data */ 2079 sync_filesystem(sb); 2080 invalidate_bdev(sb->s_bdev); 2081 } 2082 mutex_lock(&dqopt->dqonoff_mutex); 2083 if (sb_has_quota_loaded(sb, type)) { 2084 error = -EBUSY; 2085 goto out_lock; 2086 } 2087 2088 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2089 /* We don't want quota and atime on quota files (deadlocks 2090 * possible) Also nobody should write to the file - we use 2091 * special IO operations which ignore the immutable bit. */ 2092 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2093 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2094 S_NOQUOTA); 2095 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2096 mutex_unlock(&inode->i_mutex); 2097 /* 2098 * When S_NOQUOTA is set, remove dquot references as no more 2099 * references can be added 2100 */ 2101 __dquot_drop(inode); 2102 } 2103 2104 error = -EIO; 2105 dqopt->files[type] = igrab(inode); 2106 if (!dqopt->files[type]) 2107 goto out_lock; 2108 error = -EINVAL; 2109 if (!fmt->qf_ops->check_quota_file(sb, type)) 2110 goto out_file_init; 2111 2112 dqopt->ops[type] = fmt->qf_ops; 2113 dqopt->info[type].dqi_format = fmt; 2114 dqopt->info[type].dqi_fmt_id = format_id; 2115 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2116 mutex_lock(&dqopt->dqio_mutex); 2117 error = dqopt->ops[type]->read_file_info(sb, type); 2118 if (error < 0) { 2119 mutex_unlock(&dqopt->dqio_mutex); 2120 goto out_file_init; 2121 } 2122 mutex_unlock(&dqopt->dqio_mutex); 2123 spin_lock(&dq_state_lock); 2124 dqopt->flags |= dquot_state_flag(flags, type); 2125 spin_unlock(&dq_state_lock); 2126 2127 add_dquot_ref(sb, type); 2128 mutex_unlock(&dqopt->dqonoff_mutex); 2129 2130 return 0; 2131 2132 out_file_init: 2133 dqopt->files[type] = NULL; 2134 iput(inode); 2135 out_lock: 2136 if (oldflags != -1) { 2137 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2138 /* Set the flags back (in the case of accidental quotaon() 2139 * on a wrong file we don't want to mess up the flags) */ 2140 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2141 inode->i_flags |= oldflags; 2142 mutex_unlock(&inode->i_mutex); 2143 } 2144 mutex_unlock(&dqopt->dqonoff_mutex); 2145 out_fmt: 2146 put_quota_format(fmt); 2147 2148 return error; 2149 } 2150 2151 /* Reenable quotas on remount RW */ 2152 int dquot_resume(struct super_block *sb, int type) 2153 { 2154 struct quota_info *dqopt = sb_dqopt(sb); 2155 struct inode *inode; 2156 int ret = 0, cnt; 2157 unsigned int flags; 2158 2159 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2160 if (type != -1 && cnt != type) 2161 continue; 2162 2163 mutex_lock(&dqopt->dqonoff_mutex); 2164 if (!sb_has_quota_suspended(sb, cnt)) { 2165 mutex_unlock(&dqopt->dqonoff_mutex); 2166 continue; 2167 } 2168 inode = dqopt->files[cnt]; 2169 dqopt->files[cnt] = NULL; 2170 spin_lock(&dq_state_lock); 2171 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2172 DQUOT_LIMITS_ENABLED, 2173 cnt); 2174 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2175 spin_unlock(&dq_state_lock); 2176 mutex_unlock(&dqopt->dqonoff_mutex); 2177 2178 flags = dquot_generic_flag(flags, cnt); 2179 ret = vfs_load_quota_inode(inode, cnt, 2180 dqopt->info[cnt].dqi_fmt_id, flags); 2181 iput(inode); 2182 } 2183 2184 return ret; 2185 } 2186 EXPORT_SYMBOL(dquot_resume); 2187 2188 int dquot_quota_on_path(struct super_block *sb, int type, int format_id, 2189 struct path *path) 2190 { 2191 int error = security_quota_on(path->dentry); 2192 if (error) 2193 return error; 2194 /* Quota file not on the same filesystem? */ 2195 if (path->mnt->mnt_sb != sb) 2196 error = -EXDEV; 2197 else 2198 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2199 format_id, DQUOT_USAGE_ENABLED | 2200 DQUOT_LIMITS_ENABLED); 2201 return error; 2202 } 2203 EXPORT_SYMBOL(dquot_quota_on_path); 2204 2205 int dquot_quota_on(struct super_block *sb, int type, int format_id, char *name) 2206 { 2207 struct path path; 2208 int error; 2209 2210 error = kern_path(name, LOOKUP_FOLLOW, &path); 2211 if (!error) { 2212 error = dquot_quota_on_path(sb, type, format_id, &path); 2213 path_put(&path); 2214 } 2215 return error; 2216 } 2217 EXPORT_SYMBOL(dquot_quota_on); 2218 2219 /* 2220 * More powerful function for turning on quotas allowing setting 2221 * of individual quota flags 2222 */ 2223 int dquot_enable(struct inode *inode, int type, int format_id, 2224 unsigned int flags) 2225 { 2226 int ret = 0; 2227 struct super_block *sb = inode->i_sb; 2228 struct quota_info *dqopt = sb_dqopt(sb); 2229 2230 /* Just unsuspend quotas? */ 2231 BUG_ON(flags & DQUOT_SUSPENDED); 2232 2233 if (!flags) 2234 return 0; 2235 /* Just updating flags needed? */ 2236 if (sb_has_quota_loaded(sb, type)) { 2237 mutex_lock(&dqopt->dqonoff_mutex); 2238 /* Now do a reliable test... */ 2239 if (!sb_has_quota_loaded(sb, type)) { 2240 mutex_unlock(&dqopt->dqonoff_mutex); 2241 goto load_quota; 2242 } 2243 if (flags & DQUOT_USAGE_ENABLED && 2244 sb_has_quota_usage_enabled(sb, type)) { 2245 ret = -EBUSY; 2246 goto out_lock; 2247 } 2248 if (flags & DQUOT_LIMITS_ENABLED && 2249 sb_has_quota_limits_enabled(sb, type)) { 2250 ret = -EBUSY; 2251 goto out_lock; 2252 } 2253 spin_lock(&dq_state_lock); 2254 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2255 spin_unlock(&dq_state_lock); 2256 out_lock: 2257 mutex_unlock(&dqopt->dqonoff_mutex); 2258 return ret; 2259 } 2260 2261 load_quota: 2262 return vfs_load_quota_inode(inode, type, format_id, flags); 2263 } 2264 EXPORT_SYMBOL(dquot_enable); 2265 2266 /* 2267 * This function is used when filesystem needs to initialize quotas 2268 * during mount time. 2269 */ 2270 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2271 int format_id, int type) 2272 { 2273 struct dentry *dentry; 2274 int error; 2275 2276 mutex_lock(&sb->s_root->d_inode->i_mutex); 2277 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2278 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2279 if (IS_ERR(dentry)) 2280 return PTR_ERR(dentry); 2281 2282 if (!dentry->d_inode) { 2283 error = -ENOENT; 2284 goto out; 2285 } 2286 2287 error = security_quota_on(dentry); 2288 if (!error) 2289 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2290 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2291 2292 out: 2293 dput(dentry); 2294 return error; 2295 } 2296 EXPORT_SYMBOL(dquot_quota_on_mount); 2297 2298 static inline qsize_t qbtos(qsize_t blocks) 2299 { 2300 return blocks << QIF_DQBLKSIZE_BITS; 2301 } 2302 2303 static inline qsize_t stoqb(qsize_t space) 2304 { 2305 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2306 } 2307 2308 /* Generic routine for getting common part of quota structure */ 2309 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2310 { 2311 struct mem_dqblk *dm = &dquot->dq_dqb; 2312 2313 memset(di, 0, sizeof(*di)); 2314 di->d_version = FS_DQUOT_VERSION; 2315 di->d_flags = dquot->dq_type == USRQUOTA ? 2316 FS_USER_QUOTA : FS_GROUP_QUOTA; 2317 di->d_id = dquot->dq_id; 2318 2319 spin_lock(&dq_data_lock); 2320 di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit); 2321 di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit); 2322 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2323 di->d_ino_softlimit = dm->dqb_isoftlimit; 2324 di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace; 2325 di->d_icount = dm->dqb_curinodes; 2326 di->d_btimer = dm->dqb_btime; 2327 di->d_itimer = dm->dqb_itime; 2328 spin_unlock(&dq_data_lock); 2329 } 2330 2331 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id, 2332 struct fs_disk_quota *di) 2333 { 2334 struct dquot *dquot; 2335 2336 dquot = dqget(sb, id, type); 2337 if (!dquot) 2338 return -ESRCH; 2339 do_get_dqblk(dquot, di); 2340 dqput(dquot); 2341 2342 return 0; 2343 } 2344 EXPORT_SYMBOL(dquot_get_dqblk); 2345 2346 #define VFS_FS_DQ_MASK \ 2347 (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \ 2348 FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \ 2349 FS_DQ_BTIMER | FS_DQ_ITIMER) 2350 2351 /* Generic routine for setting common part of quota structure */ 2352 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2353 { 2354 struct mem_dqblk *dm = &dquot->dq_dqb; 2355 int check_blim = 0, check_ilim = 0; 2356 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2357 2358 if (di->d_fieldmask & ~VFS_FS_DQ_MASK) 2359 return -EINVAL; 2360 2361 if (((di->d_fieldmask & FS_DQ_BSOFT) && 2362 (di->d_blk_softlimit > dqi->dqi_maxblimit)) || 2363 ((di->d_fieldmask & FS_DQ_BHARD) && 2364 (di->d_blk_hardlimit > dqi->dqi_maxblimit)) || 2365 ((di->d_fieldmask & FS_DQ_ISOFT) && 2366 (di->d_ino_softlimit > dqi->dqi_maxilimit)) || 2367 ((di->d_fieldmask & FS_DQ_IHARD) && 2368 (di->d_ino_hardlimit > dqi->dqi_maxilimit))) 2369 return -ERANGE; 2370 2371 spin_lock(&dq_data_lock); 2372 if (di->d_fieldmask & FS_DQ_BCOUNT) { 2373 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace; 2374 check_blim = 1; 2375 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2376 } 2377 2378 if (di->d_fieldmask & FS_DQ_BSOFT) 2379 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit); 2380 if (di->d_fieldmask & FS_DQ_BHARD) 2381 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit); 2382 if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) { 2383 check_blim = 1; 2384 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2385 } 2386 2387 if (di->d_fieldmask & FS_DQ_ICOUNT) { 2388 dm->dqb_curinodes = di->d_icount; 2389 check_ilim = 1; 2390 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2391 } 2392 2393 if (di->d_fieldmask & FS_DQ_ISOFT) 2394 dm->dqb_isoftlimit = di->d_ino_softlimit; 2395 if (di->d_fieldmask & FS_DQ_IHARD) 2396 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2397 if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) { 2398 check_ilim = 1; 2399 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2400 } 2401 2402 if (di->d_fieldmask & FS_DQ_BTIMER) { 2403 dm->dqb_btime = di->d_btimer; 2404 check_blim = 1; 2405 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2406 } 2407 2408 if (di->d_fieldmask & FS_DQ_ITIMER) { 2409 dm->dqb_itime = di->d_itimer; 2410 check_ilim = 1; 2411 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2412 } 2413 2414 if (check_blim) { 2415 if (!dm->dqb_bsoftlimit || 2416 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2417 dm->dqb_btime = 0; 2418 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2419 } else if (!(di->d_fieldmask & FS_DQ_BTIMER)) 2420 /* Set grace only if user hasn't provided his own... */ 2421 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2422 } 2423 if (check_ilim) { 2424 if (!dm->dqb_isoftlimit || 2425 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2426 dm->dqb_itime = 0; 2427 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2428 } else if (!(di->d_fieldmask & FS_DQ_ITIMER)) 2429 /* Set grace only if user hasn't provided his own... */ 2430 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2431 } 2432 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2433 dm->dqb_isoftlimit) 2434 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2435 else 2436 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2437 spin_unlock(&dq_data_lock); 2438 mark_dquot_dirty(dquot); 2439 2440 return 0; 2441 } 2442 2443 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id, 2444 struct fs_disk_quota *di) 2445 { 2446 struct dquot *dquot; 2447 int rc; 2448 2449 dquot = dqget(sb, id, type); 2450 if (!dquot) { 2451 rc = -ESRCH; 2452 goto out; 2453 } 2454 rc = do_set_dqblk(dquot, di); 2455 dqput(dquot); 2456 out: 2457 return rc; 2458 } 2459 EXPORT_SYMBOL(dquot_set_dqblk); 2460 2461 /* Generic routine for getting common part of quota file information */ 2462 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2463 { 2464 struct mem_dqinfo *mi; 2465 2466 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2467 if (!sb_has_quota_active(sb, type)) { 2468 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2469 return -ESRCH; 2470 } 2471 mi = sb_dqopt(sb)->info + type; 2472 spin_lock(&dq_data_lock); 2473 ii->dqi_bgrace = mi->dqi_bgrace; 2474 ii->dqi_igrace = mi->dqi_igrace; 2475 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 2476 ii->dqi_valid = IIF_ALL; 2477 spin_unlock(&dq_data_lock); 2478 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2479 return 0; 2480 } 2481 EXPORT_SYMBOL(dquot_get_dqinfo); 2482 2483 /* Generic routine for setting common part of quota file information */ 2484 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2485 { 2486 struct mem_dqinfo *mi; 2487 int err = 0; 2488 2489 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2490 if (!sb_has_quota_active(sb, type)) { 2491 err = -ESRCH; 2492 goto out; 2493 } 2494 mi = sb_dqopt(sb)->info + type; 2495 spin_lock(&dq_data_lock); 2496 if (ii->dqi_valid & IIF_BGRACE) 2497 mi->dqi_bgrace = ii->dqi_bgrace; 2498 if (ii->dqi_valid & IIF_IGRACE) 2499 mi->dqi_igrace = ii->dqi_igrace; 2500 if (ii->dqi_valid & IIF_FLAGS) 2501 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | 2502 (ii->dqi_flags & DQF_MASK); 2503 spin_unlock(&dq_data_lock); 2504 mark_info_dirty(sb, type); 2505 /* Force write to disk */ 2506 sb->dq_op->write_info(sb, type); 2507 out: 2508 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2509 return err; 2510 } 2511 EXPORT_SYMBOL(dquot_set_dqinfo); 2512 2513 const struct quotactl_ops dquot_quotactl_ops = { 2514 .quota_on = dquot_quota_on, 2515 .quota_off = dquot_quota_off, 2516 .quota_sync = dquot_quota_sync, 2517 .get_info = dquot_get_dqinfo, 2518 .set_info = dquot_set_dqinfo, 2519 .get_dqblk = dquot_get_dqblk, 2520 .set_dqblk = dquot_set_dqblk 2521 }; 2522 EXPORT_SYMBOL(dquot_quotactl_ops); 2523 2524 static int do_proc_dqstats(struct ctl_table *table, int write, 2525 void __user *buffer, size_t *lenp, loff_t *ppos) 2526 { 2527 unsigned int type = (int *)table->data - dqstats.stat; 2528 2529 /* Update global table */ 2530 dqstats.stat[type] = 2531 percpu_counter_sum_positive(&dqstats.counter[type]); 2532 return proc_dointvec(table, write, buffer, lenp, ppos); 2533 } 2534 2535 static ctl_table fs_dqstats_table[] = { 2536 { 2537 .procname = "lookups", 2538 .data = &dqstats.stat[DQST_LOOKUPS], 2539 .maxlen = sizeof(int), 2540 .mode = 0444, 2541 .proc_handler = do_proc_dqstats, 2542 }, 2543 { 2544 .procname = "drops", 2545 .data = &dqstats.stat[DQST_DROPS], 2546 .maxlen = sizeof(int), 2547 .mode = 0444, 2548 .proc_handler = do_proc_dqstats, 2549 }, 2550 { 2551 .procname = "reads", 2552 .data = &dqstats.stat[DQST_READS], 2553 .maxlen = sizeof(int), 2554 .mode = 0444, 2555 .proc_handler = do_proc_dqstats, 2556 }, 2557 { 2558 .procname = "writes", 2559 .data = &dqstats.stat[DQST_WRITES], 2560 .maxlen = sizeof(int), 2561 .mode = 0444, 2562 .proc_handler = do_proc_dqstats, 2563 }, 2564 { 2565 .procname = "cache_hits", 2566 .data = &dqstats.stat[DQST_CACHE_HITS], 2567 .maxlen = sizeof(int), 2568 .mode = 0444, 2569 .proc_handler = do_proc_dqstats, 2570 }, 2571 { 2572 .procname = "allocated_dquots", 2573 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2574 .maxlen = sizeof(int), 2575 .mode = 0444, 2576 .proc_handler = do_proc_dqstats, 2577 }, 2578 { 2579 .procname = "free_dquots", 2580 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2581 .maxlen = sizeof(int), 2582 .mode = 0444, 2583 .proc_handler = do_proc_dqstats, 2584 }, 2585 { 2586 .procname = "syncs", 2587 .data = &dqstats.stat[DQST_SYNCS], 2588 .maxlen = sizeof(int), 2589 .mode = 0444, 2590 .proc_handler = do_proc_dqstats, 2591 }, 2592 #ifdef CONFIG_PRINT_QUOTA_WARNING 2593 { 2594 .procname = "warnings", 2595 .data = &flag_print_warnings, 2596 .maxlen = sizeof(int), 2597 .mode = 0644, 2598 .proc_handler = proc_dointvec, 2599 }, 2600 #endif 2601 { }, 2602 }; 2603 2604 static ctl_table fs_table[] = { 2605 { 2606 .procname = "quota", 2607 .mode = 0555, 2608 .child = fs_dqstats_table, 2609 }, 2610 { }, 2611 }; 2612 2613 static ctl_table sys_table[] = { 2614 { 2615 .procname = "fs", 2616 .mode = 0555, 2617 .child = fs_table, 2618 }, 2619 { }, 2620 }; 2621 2622 static int __init dquot_init(void) 2623 { 2624 int i, ret; 2625 unsigned long nr_hash, order; 2626 2627 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2628 2629 register_sysctl_table(sys_table); 2630 2631 dquot_cachep = kmem_cache_create("dquot", 2632 sizeof(struct dquot), sizeof(unsigned long) * 4, 2633 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2634 SLAB_MEM_SPREAD|SLAB_PANIC), 2635 NULL); 2636 2637 order = 0; 2638 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2639 if (!dquot_hash) 2640 panic("Cannot create dquot hash table"); 2641 2642 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2643 ret = percpu_counter_init(&dqstats.counter[i], 0); 2644 if (ret) 2645 panic("Cannot create dquot stat counters"); 2646 } 2647 2648 /* Find power-of-two hlist_heads which can fit into allocation */ 2649 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2650 dq_hash_bits = 0; 2651 do { 2652 dq_hash_bits++; 2653 } while (nr_hash >> dq_hash_bits); 2654 dq_hash_bits--; 2655 2656 nr_hash = 1UL << dq_hash_bits; 2657 dq_hash_mask = nr_hash - 1; 2658 for (i = 0; i < nr_hash; i++) 2659 INIT_HLIST_HEAD(dquot_hash + i); 2660 2661 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2662 nr_hash, order, (PAGE_SIZE << order)); 2663 2664 register_shrinker(&dqcache_shrinker); 2665 2666 return 0; 2667 } 2668 module_init(dquot_init); 2669