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 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 136 static char *quotatypes[] = INITQFNAMES; 137 #endif 138 static struct quota_format_type *quota_formats; /* List of registered formats */ 139 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 140 141 /* SLAB cache for dquot structures */ 142 static struct kmem_cache *dquot_cachep; 143 144 int register_quota_format(struct quota_format_type *fmt) 145 { 146 spin_lock(&dq_list_lock); 147 fmt->qf_next = quota_formats; 148 quota_formats = fmt; 149 spin_unlock(&dq_list_lock); 150 return 0; 151 } 152 EXPORT_SYMBOL(register_quota_format); 153 154 void unregister_quota_format(struct quota_format_type *fmt) 155 { 156 struct quota_format_type **actqf; 157 158 spin_lock(&dq_list_lock); 159 for (actqf = "a_formats; *actqf && *actqf != fmt; 160 actqf = &(*actqf)->qf_next) 161 ; 162 if (*actqf) 163 *actqf = (*actqf)->qf_next; 164 spin_unlock(&dq_list_lock); 165 } 166 EXPORT_SYMBOL(unregister_quota_format); 167 168 static struct quota_format_type *find_quota_format(int id) 169 { 170 struct quota_format_type *actqf; 171 172 spin_lock(&dq_list_lock); 173 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 174 actqf = actqf->qf_next) 175 ; 176 if (!actqf || !try_module_get(actqf->qf_owner)) { 177 int qm; 178 179 spin_unlock(&dq_list_lock); 180 181 for (qm = 0; module_names[qm].qm_fmt_id && 182 module_names[qm].qm_fmt_id != id; qm++) 183 ; 184 if (!module_names[qm].qm_fmt_id || 185 request_module(module_names[qm].qm_mod_name)) 186 return NULL; 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 actqf = NULL; 194 } 195 spin_unlock(&dq_list_lock); 196 return actqf; 197 } 198 199 static void put_quota_format(struct quota_format_type *fmt) 200 { 201 module_put(fmt->qf_owner); 202 } 203 204 /* 205 * Dquot List Management: 206 * The quota code uses three lists for dquot management: the inuse_list, 207 * free_dquots, and dquot_hash[] array. A single dquot structure may be 208 * on all three lists, depending on its current state. 209 * 210 * All dquots are placed to the end of inuse_list when first created, and this 211 * list is used for invalidate operation, which must look at every dquot. 212 * 213 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 214 * and this list is searched whenever we need an available dquot. Dquots are 215 * removed from the list as soon as they are used again, and 216 * dqstats.free_dquots gives the number of dquots on the list. When 217 * dquot is invalidated it's completely released from memory. 218 * 219 * Dquots with a specific identity (device, type and id) are placed on 220 * one of the dquot_hash[] hash chains. The provides an efficient search 221 * mechanism to locate a specific dquot. 222 */ 223 224 static LIST_HEAD(inuse_list); 225 static LIST_HEAD(free_dquots); 226 static unsigned int dq_hash_bits, dq_hash_mask; 227 static struct hlist_head *dquot_hash; 228 229 struct dqstats dqstats; 230 EXPORT_SYMBOL(dqstats); 231 #ifdef CONFIG_SMP 232 struct dqstats *dqstats_pcpu; 233 EXPORT_SYMBOL(dqstats_pcpu); 234 #endif 235 236 static qsize_t inode_get_rsv_space(struct inode *inode); 237 static void __dquot_initialize(struct inode *inode, int type); 238 239 static inline unsigned int 240 hashfn(const struct super_block *sb, unsigned int id, int type) 241 { 242 unsigned long tmp; 243 244 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 245 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 246 } 247 248 /* 249 * Following list functions expect dq_list_lock to be held 250 */ 251 static inline void insert_dquot_hash(struct dquot *dquot) 252 { 253 struct hlist_head *head; 254 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 255 hlist_add_head(&dquot->dq_hash, head); 256 } 257 258 static inline void remove_dquot_hash(struct dquot *dquot) 259 { 260 hlist_del_init(&dquot->dq_hash); 261 } 262 263 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 264 unsigned int id, int type) 265 { 266 struct hlist_node *node; 267 struct dquot *dquot; 268 269 hlist_for_each (node, dquot_hash+hashent) { 270 dquot = hlist_entry(node, struct dquot, dq_hash); 271 if (dquot->dq_sb == sb && dquot->dq_id == id && 272 dquot->dq_type == type) 273 return dquot; 274 } 275 return NULL; 276 } 277 278 /* Add a dquot to the tail of the free list */ 279 static inline void put_dquot_last(struct dquot *dquot) 280 { 281 list_add_tail(&dquot->dq_free, &free_dquots); 282 dqstats_inc(DQST_FREE_DQUOTS); 283 } 284 285 static inline void remove_free_dquot(struct dquot *dquot) 286 { 287 if (list_empty(&dquot->dq_free)) 288 return; 289 list_del_init(&dquot->dq_free); 290 dqstats_dec(DQST_FREE_DQUOTS); 291 } 292 293 static inline void put_inuse(struct dquot *dquot) 294 { 295 /* We add to the back of inuse list so we don't have to restart 296 * when traversing this list and we block */ 297 list_add_tail(&dquot->dq_inuse, &inuse_list); 298 dqstats_inc(DQST_ALLOC_DQUOTS); 299 } 300 301 static inline void remove_inuse(struct dquot *dquot) 302 { 303 dqstats_dec(DQST_ALLOC_DQUOTS); 304 list_del(&dquot->dq_inuse); 305 } 306 /* 307 * End of list functions needing dq_list_lock 308 */ 309 310 static void wait_on_dquot(struct dquot *dquot) 311 { 312 mutex_lock(&dquot->dq_lock); 313 mutex_unlock(&dquot->dq_lock); 314 } 315 316 static inline int dquot_dirty(struct dquot *dquot) 317 { 318 return test_bit(DQ_MOD_B, &dquot->dq_flags); 319 } 320 321 static inline int mark_dquot_dirty(struct dquot *dquot) 322 { 323 return dquot->dq_sb->dq_op->mark_dirty(dquot); 324 } 325 326 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 327 int dquot_mark_dquot_dirty(struct dquot *dquot) 328 { 329 int ret = 1; 330 331 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 332 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 333 return 1; 334 335 spin_lock(&dq_list_lock); 336 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 337 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 338 info[dquot->dq_type].dqi_dirty_list); 339 ret = 0; 340 } 341 spin_unlock(&dq_list_lock); 342 return ret; 343 } 344 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 345 346 /* Dirtify all the dquots - this can block when journalling */ 347 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 348 { 349 int ret, err, cnt; 350 351 ret = err = 0; 352 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 353 if (dquot[cnt]) 354 /* Even in case of error we have to continue */ 355 ret = mark_dquot_dirty(dquot[cnt]); 356 if (!err) 357 err = ret; 358 } 359 return err; 360 } 361 362 static inline void dqput_all(struct dquot **dquot) 363 { 364 unsigned int cnt; 365 366 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 367 dqput(dquot[cnt]); 368 } 369 370 /* This function needs dq_list_lock */ 371 static inline int clear_dquot_dirty(struct dquot *dquot) 372 { 373 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 374 return 0; 375 list_del_init(&dquot->dq_dirty); 376 return 1; 377 } 378 379 void mark_info_dirty(struct super_block *sb, int type) 380 { 381 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 382 } 383 EXPORT_SYMBOL(mark_info_dirty); 384 385 /* 386 * Read dquot from disk and alloc space for it 387 */ 388 389 int dquot_acquire(struct dquot *dquot) 390 { 391 int ret = 0, ret2 = 0; 392 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 393 394 mutex_lock(&dquot->dq_lock); 395 mutex_lock(&dqopt->dqio_mutex); 396 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 397 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 398 if (ret < 0) 399 goto out_iolock; 400 set_bit(DQ_READ_B, &dquot->dq_flags); 401 /* Instantiate dquot if needed */ 402 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 403 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 404 /* Write the info if needed */ 405 if (info_dirty(&dqopt->info[dquot->dq_type])) { 406 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 407 dquot->dq_sb, dquot->dq_type); 408 } 409 if (ret < 0) 410 goto out_iolock; 411 if (ret2 < 0) { 412 ret = ret2; 413 goto out_iolock; 414 } 415 } 416 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 417 out_iolock: 418 mutex_unlock(&dqopt->dqio_mutex); 419 mutex_unlock(&dquot->dq_lock); 420 return ret; 421 } 422 EXPORT_SYMBOL(dquot_acquire); 423 424 /* 425 * Write dquot to disk 426 */ 427 int dquot_commit(struct dquot *dquot) 428 { 429 int ret = 0, ret2 = 0; 430 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 431 432 mutex_lock(&dqopt->dqio_mutex); 433 spin_lock(&dq_list_lock); 434 if (!clear_dquot_dirty(dquot)) { 435 spin_unlock(&dq_list_lock); 436 goto out_sem; 437 } 438 spin_unlock(&dq_list_lock); 439 /* Inactive dquot can be only if there was error during read/init 440 * => we have better not writing it */ 441 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 442 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 443 if (info_dirty(&dqopt->info[dquot->dq_type])) { 444 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 445 dquot->dq_sb, dquot->dq_type); 446 } 447 if (ret >= 0) 448 ret = ret2; 449 } 450 out_sem: 451 mutex_unlock(&dqopt->dqio_mutex); 452 return ret; 453 } 454 EXPORT_SYMBOL(dquot_commit); 455 456 /* 457 * Release dquot 458 */ 459 int dquot_release(struct dquot *dquot) 460 { 461 int ret = 0, ret2 = 0; 462 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 463 464 mutex_lock(&dquot->dq_lock); 465 /* Check whether we are not racing with some other dqget() */ 466 if (atomic_read(&dquot->dq_count) > 1) 467 goto out_dqlock; 468 mutex_lock(&dqopt->dqio_mutex); 469 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 470 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 471 /* Write the info */ 472 if (info_dirty(&dqopt->info[dquot->dq_type])) { 473 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 474 dquot->dq_sb, dquot->dq_type); 475 } 476 if (ret >= 0) 477 ret = ret2; 478 } 479 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 480 mutex_unlock(&dqopt->dqio_mutex); 481 out_dqlock: 482 mutex_unlock(&dquot->dq_lock); 483 return ret; 484 } 485 EXPORT_SYMBOL(dquot_release); 486 487 void dquot_destroy(struct dquot *dquot) 488 { 489 kmem_cache_free(dquot_cachep, dquot); 490 } 491 EXPORT_SYMBOL(dquot_destroy); 492 493 static inline void do_destroy_dquot(struct dquot *dquot) 494 { 495 dquot->dq_sb->dq_op->destroy_dquot(dquot); 496 } 497 498 /* Invalidate all dquots on the list. Note that this function is called after 499 * quota is disabled and pointers from inodes removed so there cannot be new 500 * quota users. There can still be some users of quotas due to inodes being 501 * just deleted or pruned by prune_icache() (those are not attached to any 502 * list) or parallel quotactl call. We have to wait for such users. 503 */ 504 static void invalidate_dquots(struct super_block *sb, int type) 505 { 506 struct dquot *dquot, *tmp; 507 508 restart: 509 spin_lock(&dq_list_lock); 510 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 511 if (dquot->dq_sb != sb) 512 continue; 513 if (dquot->dq_type != type) 514 continue; 515 /* Wait for dquot users */ 516 if (atomic_read(&dquot->dq_count)) { 517 DEFINE_WAIT(wait); 518 519 atomic_inc(&dquot->dq_count); 520 prepare_to_wait(&dquot->dq_wait_unused, &wait, 521 TASK_UNINTERRUPTIBLE); 522 spin_unlock(&dq_list_lock); 523 /* Once dqput() wakes us up, we know it's time to free 524 * the dquot. 525 * IMPORTANT: we rely on the fact that there is always 526 * at most one process waiting for dquot to free. 527 * Otherwise dq_count would be > 1 and we would never 528 * wake up. 529 */ 530 if (atomic_read(&dquot->dq_count) > 1) 531 schedule(); 532 finish_wait(&dquot->dq_wait_unused, &wait); 533 dqput(dquot); 534 /* At this moment dquot() need not exist (it could be 535 * reclaimed by prune_dqcache(). Hence we must 536 * restart. */ 537 goto restart; 538 } 539 /* 540 * Quota now has no users and it has been written on last 541 * dqput() 542 */ 543 remove_dquot_hash(dquot); 544 remove_free_dquot(dquot); 545 remove_inuse(dquot); 546 do_destroy_dquot(dquot); 547 } 548 spin_unlock(&dq_list_lock); 549 } 550 551 /* Call callback for every active dquot on given filesystem */ 552 int dquot_scan_active(struct super_block *sb, 553 int (*fn)(struct dquot *dquot, unsigned long priv), 554 unsigned long priv) 555 { 556 struct dquot *dquot, *old_dquot = NULL; 557 int ret = 0; 558 559 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 560 spin_lock(&dq_list_lock); 561 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 562 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 563 continue; 564 if (dquot->dq_sb != sb) 565 continue; 566 /* Now we have active dquot so we can just increase use count */ 567 atomic_inc(&dquot->dq_count); 568 spin_unlock(&dq_list_lock); 569 dqstats_inc(DQST_LOOKUPS); 570 dqput(old_dquot); 571 old_dquot = dquot; 572 ret = fn(dquot, priv); 573 if (ret < 0) 574 goto out; 575 spin_lock(&dq_list_lock); 576 /* We are safe to continue now because our dquot could not 577 * be moved out of the inuse list while we hold the reference */ 578 } 579 spin_unlock(&dq_list_lock); 580 out: 581 dqput(old_dquot); 582 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 583 return ret; 584 } 585 EXPORT_SYMBOL(dquot_scan_active); 586 587 int dquot_quota_sync(struct super_block *sb, int type, int wait) 588 { 589 struct list_head *dirty; 590 struct dquot *dquot; 591 struct quota_info *dqopt = sb_dqopt(sb); 592 int cnt; 593 594 mutex_lock(&dqopt->dqonoff_mutex); 595 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 596 if (type != -1 && cnt != type) 597 continue; 598 if (!sb_has_quota_active(sb, cnt)) 599 continue; 600 spin_lock(&dq_list_lock); 601 dirty = &dqopt->info[cnt].dqi_dirty_list; 602 while (!list_empty(dirty)) { 603 dquot = list_first_entry(dirty, struct dquot, 604 dq_dirty); 605 /* Dirty and inactive can be only bad dquot... */ 606 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 607 clear_dquot_dirty(dquot); 608 continue; 609 } 610 /* Now we have active dquot from which someone is 611 * holding reference so we can safely just increase 612 * use count */ 613 atomic_inc(&dquot->dq_count); 614 spin_unlock(&dq_list_lock); 615 dqstats_inc(DQST_LOOKUPS); 616 sb->dq_op->write_dquot(dquot); 617 dqput(dquot); 618 spin_lock(&dq_list_lock); 619 } 620 spin_unlock(&dq_list_lock); 621 } 622 623 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 624 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 625 && info_dirty(&dqopt->info[cnt])) 626 sb->dq_op->write_info(sb, cnt); 627 dqstats_inc(DQST_SYNCS); 628 mutex_unlock(&dqopt->dqonoff_mutex); 629 630 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)) 631 return 0; 632 633 /* This is not very clever (and fast) but currently I don't know about 634 * any other simple way of getting quota data to disk and we must get 635 * them there for userspace to be visible... */ 636 if (sb->s_op->sync_fs) 637 sb->s_op->sync_fs(sb, 1); 638 sync_blockdev(sb->s_bdev); 639 640 /* 641 * Now when everything is written we can discard the pagecache so 642 * that userspace sees the changes. 643 */ 644 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 645 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 646 if (type != -1 && cnt != type) 647 continue; 648 if (!sb_has_quota_active(sb, cnt)) 649 continue; 650 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, 651 I_MUTEX_QUOTA); 652 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); 653 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); 654 } 655 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 656 657 return 0; 658 } 659 EXPORT_SYMBOL(dquot_quota_sync); 660 661 /* Free unused dquots from cache */ 662 static void prune_dqcache(int count) 663 { 664 struct list_head *head; 665 struct dquot *dquot; 666 667 head = free_dquots.prev; 668 while (head != &free_dquots && count) { 669 dquot = list_entry(head, struct dquot, dq_free); 670 remove_dquot_hash(dquot); 671 remove_free_dquot(dquot); 672 remove_inuse(dquot); 673 do_destroy_dquot(dquot); 674 count--; 675 head = free_dquots.prev; 676 } 677 } 678 679 static int dqstats_read(unsigned int type) 680 { 681 int count = 0; 682 #ifdef CONFIG_SMP 683 int cpu; 684 for_each_possible_cpu(cpu) 685 count += per_cpu_ptr(dqstats_pcpu, cpu)->stat[type]; 686 /* Statistics reading is racy, but absolute accuracy isn't required */ 687 if (count < 0) 688 count = 0; 689 #else 690 count = dqstats.stat[type]; 691 #endif 692 return count; 693 } 694 695 /* 696 * This is called from kswapd when we think we need some 697 * more memory 698 */ 699 700 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 701 { 702 if (nr) { 703 spin_lock(&dq_list_lock); 704 prune_dqcache(nr); 705 spin_unlock(&dq_list_lock); 706 } 707 return (dqstats_read(DQST_FREE_DQUOTS)/100) * sysctl_vfs_cache_pressure; 708 } 709 710 static struct shrinker dqcache_shrinker = { 711 .shrink = shrink_dqcache_memory, 712 .seeks = DEFAULT_SEEKS, 713 }; 714 715 /* 716 * Put reference to dquot 717 * NOTE: If you change this function please check whether dqput_blocks() works right... 718 */ 719 void dqput(struct dquot *dquot) 720 { 721 int ret; 722 723 if (!dquot) 724 return; 725 #ifdef CONFIG_QUOTA_DEBUG 726 if (!atomic_read(&dquot->dq_count)) { 727 printk("VFS: dqput: trying to free free dquot\n"); 728 printk("VFS: device %s, dquot of %s %d\n", 729 dquot->dq_sb->s_id, 730 quotatypes[dquot->dq_type], 731 dquot->dq_id); 732 BUG(); 733 } 734 #endif 735 dqstats_inc(DQST_DROPS); 736 we_slept: 737 spin_lock(&dq_list_lock); 738 if (atomic_read(&dquot->dq_count) > 1) { 739 /* We have more than one user... nothing to do */ 740 atomic_dec(&dquot->dq_count); 741 /* Releasing dquot during quotaoff phase? */ 742 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 743 atomic_read(&dquot->dq_count) == 1) 744 wake_up(&dquot->dq_wait_unused); 745 spin_unlock(&dq_list_lock); 746 return; 747 } 748 /* Need to release dquot? */ 749 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 750 spin_unlock(&dq_list_lock); 751 /* Commit dquot before releasing */ 752 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 753 if (ret < 0) { 754 printk(KERN_ERR "VFS: cannot write quota structure on " 755 "device %s (error %d). Quota may get out of " 756 "sync!\n", dquot->dq_sb->s_id, ret); 757 /* 758 * We clear dirty bit anyway, so that we avoid 759 * infinite loop here 760 */ 761 spin_lock(&dq_list_lock); 762 clear_dquot_dirty(dquot); 763 spin_unlock(&dq_list_lock); 764 } 765 goto we_slept; 766 } 767 /* Clear flag in case dquot was inactive (something bad happened) */ 768 clear_dquot_dirty(dquot); 769 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 770 spin_unlock(&dq_list_lock); 771 dquot->dq_sb->dq_op->release_dquot(dquot); 772 goto we_slept; 773 } 774 atomic_dec(&dquot->dq_count); 775 #ifdef CONFIG_QUOTA_DEBUG 776 /* sanity check */ 777 BUG_ON(!list_empty(&dquot->dq_free)); 778 #endif 779 put_dquot_last(dquot); 780 spin_unlock(&dq_list_lock); 781 } 782 EXPORT_SYMBOL(dqput); 783 784 struct dquot *dquot_alloc(struct super_block *sb, int type) 785 { 786 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 787 } 788 EXPORT_SYMBOL(dquot_alloc); 789 790 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 791 { 792 struct dquot *dquot; 793 794 dquot = sb->dq_op->alloc_dquot(sb, type); 795 if(!dquot) 796 return NULL; 797 798 mutex_init(&dquot->dq_lock); 799 INIT_LIST_HEAD(&dquot->dq_free); 800 INIT_LIST_HEAD(&dquot->dq_inuse); 801 INIT_HLIST_NODE(&dquot->dq_hash); 802 INIT_LIST_HEAD(&dquot->dq_dirty); 803 init_waitqueue_head(&dquot->dq_wait_unused); 804 dquot->dq_sb = sb; 805 dquot->dq_type = type; 806 atomic_set(&dquot->dq_count, 1); 807 808 return dquot; 809 } 810 811 /* 812 * Get reference to dquot 813 * 814 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 815 * destroying our dquot by: 816 * a) checking for quota flags under dq_list_lock and 817 * b) getting a reference to dquot before we release dq_list_lock 818 */ 819 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 820 { 821 unsigned int hashent = hashfn(sb, id, type); 822 struct dquot *dquot = NULL, *empty = NULL; 823 824 if (!sb_has_quota_active(sb, type)) 825 return NULL; 826 we_slept: 827 spin_lock(&dq_list_lock); 828 spin_lock(&dq_state_lock); 829 if (!sb_has_quota_active(sb, type)) { 830 spin_unlock(&dq_state_lock); 831 spin_unlock(&dq_list_lock); 832 goto out; 833 } 834 spin_unlock(&dq_state_lock); 835 836 dquot = find_dquot(hashent, sb, id, type); 837 if (!dquot) { 838 if (!empty) { 839 spin_unlock(&dq_list_lock); 840 empty = get_empty_dquot(sb, type); 841 if (!empty) 842 schedule(); /* Try to wait for a moment... */ 843 goto we_slept; 844 } 845 dquot = empty; 846 empty = NULL; 847 dquot->dq_id = id; 848 /* all dquots go on the inuse_list */ 849 put_inuse(dquot); 850 /* hash it first so it can be found */ 851 insert_dquot_hash(dquot); 852 spin_unlock(&dq_list_lock); 853 dqstats_inc(DQST_LOOKUPS); 854 } else { 855 if (!atomic_read(&dquot->dq_count)) 856 remove_free_dquot(dquot); 857 atomic_inc(&dquot->dq_count); 858 spin_unlock(&dq_list_lock); 859 dqstats_inc(DQST_CACHE_HITS); 860 dqstats_inc(DQST_LOOKUPS); 861 } 862 /* Wait for dq_lock - after this we know that either dquot_release() is 863 * already finished or it will be canceled due to dq_count > 1 test */ 864 wait_on_dquot(dquot); 865 /* Read the dquot / allocate space in quota file */ 866 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 867 sb->dq_op->acquire_dquot(dquot) < 0) { 868 dqput(dquot); 869 dquot = NULL; 870 goto out; 871 } 872 #ifdef CONFIG_QUOTA_DEBUG 873 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 874 #endif 875 out: 876 if (empty) 877 do_destroy_dquot(empty); 878 879 return dquot; 880 } 881 EXPORT_SYMBOL(dqget); 882 883 static int dqinit_needed(struct inode *inode, int type) 884 { 885 int cnt; 886 887 if (IS_NOQUOTA(inode)) 888 return 0; 889 if (type != -1) 890 return !inode->i_dquot[type]; 891 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 892 if (!inode->i_dquot[cnt]) 893 return 1; 894 return 0; 895 } 896 897 /* This routine is guarded by dqonoff_mutex mutex */ 898 static void add_dquot_ref(struct super_block *sb, int type) 899 { 900 struct inode *inode, *old_inode = NULL; 901 #ifdef CONFIG_QUOTA_DEBUG 902 int reserved = 0; 903 #endif 904 905 spin_lock(&inode_lock); 906 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 907 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) 908 continue; 909 #ifdef CONFIG_QUOTA_DEBUG 910 if (unlikely(inode_get_rsv_space(inode) > 0)) 911 reserved = 1; 912 #endif 913 if (!atomic_read(&inode->i_writecount)) 914 continue; 915 if (!dqinit_needed(inode, type)) 916 continue; 917 918 __iget(inode); 919 spin_unlock(&inode_lock); 920 921 iput(old_inode); 922 __dquot_initialize(inode, type); 923 /* We hold a reference to 'inode' so it couldn't have been 924 * removed from s_inodes list while we dropped the inode_lock. 925 * We cannot iput the inode now as we can be holding the last 926 * reference and we cannot iput it under inode_lock. So we 927 * keep the reference and iput it later. */ 928 old_inode = inode; 929 spin_lock(&inode_lock); 930 } 931 spin_unlock(&inode_lock); 932 iput(old_inode); 933 934 #ifdef CONFIG_QUOTA_DEBUG 935 if (reserved) { 936 printk(KERN_WARNING "VFS (%s): Writes happened before quota" 937 " was turned on thus quota information is probably " 938 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 939 } 940 #endif 941 } 942 943 /* 944 * Return 0 if dqput() won't block. 945 * (note that 1 doesn't necessarily mean blocking) 946 */ 947 static inline int dqput_blocks(struct dquot *dquot) 948 { 949 if (atomic_read(&dquot->dq_count) <= 1) 950 return 1; 951 return 0; 952 } 953 954 /* 955 * Remove references to dquots from inode and add dquot to list for freeing 956 * if we have the last referece to dquot 957 * We can't race with anybody because we hold dqptr_sem for writing... 958 */ 959 static int remove_inode_dquot_ref(struct inode *inode, int type, 960 struct list_head *tofree_head) 961 { 962 struct dquot *dquot = inode->i_dquot[type]; 963 964 inode->i_dquot[type] = NULL; 965 if (dquot) { 966 if (dqput_blocks(dquot)) { 967 #ifdef CONFIG_QUOTA_DEBUG 968 if (atomic_read(&dquot->dq_count) != 1) 969 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); 970 #endif 971 spin_lock(&dq_list_lock); 972 /* As dquot must have currently users it can't be on 973 * the free list... */ 974 list_add(&dquot->dq_free, tofree_head); 975 spin_unlock(&dq_list_lock); 976 return 1; 977 } 978 else 979 dqput(dquot); /* We have guaranteed we won't block */ 980 } 981 return 0; 982 } 983 984 /* 985 * Free list of dquots 986 * Dquots are removed from inodes and no new references can be got so we are 987 * the only ones holding reference 988 */ 989 static void put_dquot_list(struct list_head *tofree_head) 990 { 991 struct list_head *act_head; 992 struct dquot *dquot; 993 994 act_head = tofree_head->next; 995 while (act_head != tofree_head) { 996 dquot = list_entry(act_head, struct dquot, dq_free); 997 act_head = act_head->next; 998 /* Remove dquot from the list so we won't have problems... */ 999 list_del_init(&dquot->dq_free); 1000 dqput(dquot); 1001 } 1002 } 1003 1004 static void remove_dquot_ref(struct super_block *sb, int type, 1005 struct list_head *tofree_head) 1006 { 1007 struct inode *inode; 1008 1009 spin_lock(&inode_lock); 1010 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1011 /* 1012 * We have to scan also I_NEW inodes because they can already 1013 * have quota pointer initialized. Luckily, we need to touch 1014 * only quota pointers and these have separate locking 1015 * (dqptr_sem). 1016 */ 1017 if (!IS_NOQUOTA(inode)) 1018 remove_inode_dquot_ref(inode, type, tofree_head); 1019 } 1020 spin_unlock(&inode_lock); 1021 } 1022 1023 /* Gather all references from inodes and drop them */ 1024 static void drop_dquot_ref(struct super_block *sb, int type) 1025 { 1026 LIST_HEAD(tofree_head); 1027 1028 if (sb->dq_op) { 1029 down_write(&sb_dqopt(sb)->dqptr_sem); 1030 remove_dquot_ref(sb, type, &tofree_head); 1031 up_write(&sb_dqopt(sb)->dqptr_sem); 1032 put_dquot_list(&tofree_head); 1033 } 1034 } 1035 1036 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1037 { 1038 dquot->dq_dqb.dqb_curinodes += number; 1039 } 1040 1041 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1042 { 1043 dquot->dq_dqb.dqb_curspace += number; 1044 } 1045 1046 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1047 { 1048 dquot->dq_dqb.dqb_rsvspace += number; 1049 } 1050 1051 /* 1052 * Claim reserved quota space 1053 */ 1054 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1055 { 1056 if (dquot->dq_dqb.dqb_rsvspace < number) { 1057 WARN_ON_ONCE(1); 1058 number = dquot->dq_dqb.dqb_rsvspace; 1059 } 1060 dquot->dq_dqb.dqb_curspace += number; 1061 dquot->dq_dqb.dqb_rsvspace -= number; 1062 } 1063 1064 static inline 1065 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1066 { 1067 if (dquot->dq_dqb.dqb_rsvspace >= number) 1068 dquot->dq_dqb.dqb_rsvspace -= number; 1069 else { 1070 WARN_ON_ONCE(1); 1071 dquot->dq_dqb.dqb_rsvspace = 0; 1072 } 1073 } 1074 1075 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1076 { 1077 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1078 dquot->dq_dqb.dqb_curinodes >= number) 1079 dquot->dq_dqb.dqb_curinodes -= number; 1080 else 1081 dquot->dq_dqb.dqb_curinodes = 0; 1082 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1083 dquot->dq_dqb.dqb_itime = (time_t) 0; 1084 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1085 } 1086 1087 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1088 { 1089 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1090 dquot->dq_dqb.dqb_curspace >= number) 1091 dquot->dq_dqb.dqb_curspace -= number; 1092 else 1093 dquot->dq_dqb.dqb_curspace = 0; 1094 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1095 dquot->dq_dqb.dqb_btime = (time_t) 0; 1096 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1097 } 1098 1099 static int warning_issued(struct dquot *dquot, const int warntype) 1100 { 1101 int flag = (warntype == QUOTA_NL_BHARDWARN || 1102 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1103 ((warntype == QUOTA_NL_IHARDWARN || 1104 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1105 1106 if (!flag) 1107 return 0; 1108 return test_and_set_bit(flag, &dquot->dq_flags); 1109 } 1110 1111 #ifdef CONFIG_PRINT_QUOTA_WARNING 1112 static int flag_print_warnings = 1; 1113 1114 static int need_print_warning(struct dquot *dquot) 1115 { 1116 if (!flag_print_warnings) 1117 return 0; 1118 1119 switch (dquot->dq_type) { 1120 case USRQUOTA: 1121 return current_fsuid() == dquot->dq_id; 1122 case GRPQUOTA: 1123 return in_group_p(dquot->dq_id); 1124 } 1125 return 0; 1126 } 1127 1128 /* Print warning to user which exceeded quota */ 1129 static void print_warning(struct dquot *dquot, const int warntype) 1130 { 1131 char *msg = NULL; 1132 struct tty_struct *tty; 1133 1134 if (warntype == QUOTA_NL_IHARDBELOW || 1135 warntype == QUOTA_NL_ISOFTBELOW || 1136 warntype == QUOTA_NL_BHARDBELOW || 1137 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1138 return; 1139 1140 tty = get_current_tty(); 1141 if (!tty) 1142 return; 1143 tty_write_message(tty, dquot->dq_sb->s_id); 1144 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1145 tty_write_message(tty, ": warning, "); 1146 else 1147 tty_write_message(tty, ": write failed, "); 1148 tty_write_message(tty, quotatypes[dquot->dq_type]); 1149 switch (warntype) { 1150 case QUOTA_NL_IHARDWARN: 1151 msg = " file limit reached.\r\n"; 1152 break; 1153 case QUOTA_NL_ISOFTLONGWARN: 1154 msg = " file quota exceeded too long.\r\n"; 1155 break; 1156 case QUOTA_NL_ISOFTWARN: 1157 msg = " file quota exceeded.\r\n"; 1158 break; 1159 case QUOTA_NL_BHARDWARN: 1160 msg = " block limit reached.\r\n"; 1161 break; 1162 case QUOTA_NL_BSOFTLONGWARN: 1163 msg = " block quota exceeded too long.\r\n"; 1164 break; 1165 case QUOTA_NL_BSOFTWARN: 1166 msg = " block quota exceeded.\r\n"; 1167 break; 1168 } 1169 tty_write_message(tty, msg); 1170 tty_kref_put(tty); 1171 } 1172 #endif 1173 1174 /* 1175 * Write warnings to the console and send warning messages over netlink. 1176 * 1177 * Note that this function can sleep. 1178 */ 1179 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1180 { 1181 struct dquot *dq; 1182 int i; 1183 1184 for (i = 0; i < MAXQUOTAS; i++) { 1185 dq = dquots[i]; 1186 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1187 !warning_issued(dq, warntype[i])) { 1188 #ifdef CONFIG_PRINT_QUOTA_WARNING 1189 print_warning(dq, warntype[i]); 1190 #endif 1191 quota_send_warning(dq->dq_type, dq->dq_id, 1192 dq->dq_sb->s_dev, warntype[i]); 1193 } 1194 } 1195 } 1196 1197 static int ignore_hardlimit(struct dquot *dquot) 1198 { 1199 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1200 1201 return capable(CAP_SYS_RESOURCE) && 1202 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1203 !(info->dqi_flags & V1_DQF_RSQUASH)); 1204 } 1205 1206 /* needs dq_data_lock */ 1207 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1208 { 1209 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1210 1211 *warntype = QUOTA_NL_NOWARN; 1212 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1213 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1214 return 0; 1215 1216 if (dquot->dq_dqb.dqb_ihardlimit && 1217 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1218 !ignore_hardlimit(dquot)) { 1219 *warntype = QUOTA_NL_IHARDWARN; 1220 return -EDQUOT; 1221 } 1222 1223 if (dquot->dq_dqb.dqb_isoftlimit && 1224 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1225 dquot->dq_dqb.dqb_itime && 1226 get_seconds() >= dquot->dq_dqb.dqb_itime && 1227 !ignore_hardlimit(dquot)) { 1228 *warntype = QUOTA_NL_ISOFTLONGWARN; 1229 return -EDQUOT; 1230 } 1231 1232 if (dquot->dq_dqb.dqb_isoftlimit && 1233 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1234 dquot->dq_dqb.dqb_itime == 0) { 1235 *warntype = QUOTA_NL_ISOFTWARN; 1236 dquot->dq_dqb.dqb_itime = get_seconds() + 1237 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1238 } 1239 1240 return 0; 1241 } 1242 1243 /* needs dq_data_lock */ 1244 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1245 { 1246 qsize_t tspace; 1247 struct super_block *sb = dquot->dq_sb; 1248 1249 *warntype = QUOTA_NL_NOWARN; 1250 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1251 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1252 return 0; 1253 1254 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1255 + space; 1256 1257 if (dquot->dq_dqb.dqb_bhardlimit && 1258 tspace > dquot->dq_dqb.dqb_bhardlimit && 1259 !ignore_hardlimit(dquot)) { 1260 if (!prealloc) 1261 *warntype = QUOTA_NL_BHARDWARN; 1262 return -EDQUOT; 1263 } 1264 1265 if (dquot->dq_dqb.dqb_bsoftlimit && 1266 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1267 dquot->dq_dqb.dqb_btime && 1268 get_seconds() >= dquot->dq_dqb.dqb_btime && 1269 !ignore_hardlimit(dquot)) { 1270 if (!prealloc) 1271 *warntype = QUOTA_NL_BSOFTLONGWARN; 1272 return -EDQUOT; 1273 } 1274 1275 if (dquot->dq_dqb.dqb_bsoftlimit && 1276 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1277 dquot->dq_dqb.dqb_btime == 0) { 1278 if (!prealloc) { 1279 *warntype = QUOTA_NL_BSOFTWARN; 1280 dquot->dq_dqb.dqb_btime = get_seconds() + 1281 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1282 } 1283 else 1284 /* 1285 * We don't allow preallocation to exceed softlimit so exceeding will 1286 * be always printed 1287 */ 1288 return -EDQUOT; 1289 } 1290 1291 return 0; 1292 } 1293 1294 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1295 { 1296 qsize_t newinodes; 1297 1298 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1299 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1300 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1301 return QUOTA_NL_NOWARN; 1302 1303 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1304 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1305 return QUOTA_NL_ISOFTBELOW; 1306 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1307 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1308 return QUOTA_NL_IHARDBELOW; 1309 return QUOTA_NL_NOWARN; 1310 } 1311 1312 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1313 { 1314 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1315 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1316 return QUOTA_NL_NOWARN; 1317 1318 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1319 return QUOTA_NL_BSOFTBELOW; 1320 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1321 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1322 return QUOTA_NL_BHARDBELOW; 1323 return QUOTA_NL_NOWARN; 1324 } 1325 1326 /* 1327 * Initialize quota pointers in inode 1328 * 1329 * We do things in a bit complicated way but by that we avoid calling 1330 * dqget() and thus filesystem callbacks under dqptr_sem. 1331 * 1332 * It is better to call this function outside of any transaction as it 1333 * might need a lot of space in journal for dquot structure allocation. 1334 */ 1335 static void __dquot_initialize(struct inode *inode, int type) 1336 { 1337 unsigned int id = 0; 1338 int cnt; 1339 struct dquot *got[MAXQUOTAS]; 1340 struct super_block *sb = inode->i_sb; 1341 qsize_t rsv; 1342 1343 /* First test before acquiring mutex - solves deadlocks when we 1344 * re-enter the quota code and are already holding the mutex */ 1345 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1346 return; 1347 1348 /* First get references to structures we might need. */ 1349 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1350 got[cnt] = NULL; 1351 if (type != -1 && cnt != type) 1352 continue; 1353 switch (cnt) { 1354 case USRQUOTA: 1355 id = inode->i_uid; 1356 break; 1357 case GRPQUOTA: 1358 id = inode->i_gid; 1359 break; 1360 } 1361 got[cnt] = dqget(sb, id, cnt); 1362 } 1363 1364 down_write(&sb_dqopt(sb)->dqptr_sem); 1365 if (IS_NOQUOTA(inode)) 1366 goto out_err; 1367 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1368 if (type != -1 && cnt != type) 1369 continue; 1370 /* Avoid races with quotaoff() */ 1371 if (!sb_has_quota_active(sb, cnt)) 1372 continue; 1373 if (!inode->i_dquot[cnt]) { 1374 inode->i_dquot[cnt] = got[cnt]; 1375 got[cnt] = NULL; 1376 /* 1377 * Make quota reservation system happy if someone 1378 * did a write before quota was turned on 1379 */ 1380 rsv = inode_get_rsv_space(inode); 1381 if (unlikely(rsv)) 1382 dquot_resv_space(inode->i_dquot[cnt], rsv); 1383 } 1384 } 1385 out_err: 1386 up_write(&sb_dqopt(sb)->dqptr_sem); 1387 /* Drop unused references */ 1388 dqput_all(got); 1389 } 1390 1391 void dquot_initialize(struct inode *inode) 1392 { 1393 __dquot_initialize(inode, -1); 1394 } 1395 EXPORT_SYMBOL(dquot_initialize); 1396 1397 /* 1398 * Release all quotas referenced by inode 1399 */ 1400 static void __dquot_drop(struct inode *inode) 1401 { 1402 int cnt; 1403 struct dquot *put[MAXQUOTAS]; 1404 1405 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1406 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1407 put[cnt] = inode->i_dquot[cnt]; 1408 inode->i_dquot[cnt] = NULL; 1409 } 1410 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1411 dqput_all(put); 1412 } 1413 1414 void dquot_drop(struct inode *inode) 1415 { 1416 int cnt; 1417 1418 if (IS_NOQUOTA(inode)) 1419 return; 1420 1421 /* 1422 * Test before calling to rule out calls from proc and such 1423 * where we are not allowed to block. Note that this is 1424 * actually reliable test even without the lock - the caller 1425 * must assure that nobody can come after the DQUOT_DROP and 1426 * add quota pointers back anyway. 1427 */ 1428 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1429 if (inode->i_dquot[cnt]) 1430 break; 1431 } 1432 1433 if (cnt < MAXQUOTAS) 1434 __dquot_drop(inode); 1435 } 1436 EXPORT_SYMBOL(dquot_drop); 1437 1438 /* 1439 * inode_reserved_space is managed internally by quota, and protected by 1440 * i_lock similar to i_blocks+i_bytes. 1441 */ 1442 static qsize_t *inode_reserved_space(struct inode * inode) 1443 { 1444 /* Filesystem must explicitly define it's own method in order to use 1445 * quota reservation interface */ 1446 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1447 return inode->i_sb->dq_op->get_reserved_space(inode); 1448 } 1449 1450 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1451 { 1452 spin_lock(&inode->i_lock); 1453 *inode_reserved_space(inode) += number; 1454 spin_unlock(&inode->i_lock); 1455 } 1456 EXPORT_SYMBOL(inode_add_rsv_space); 1457 1458 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1459 { 1460 spin_lock(&inode->i_lock); 1461 *inode_reserved_space(inode) -= number; 1462 __inode_add_bytes(inode, number); 1463 spin_unlock(&inode->i_lock); 1464 } 1465 EXPORT_SYMBOL(inode_claim_rsv_space); 1466 1467 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1468 { 1469 spin_lock(&inode->i_lock); 1470 *inode_reserved_space(inode) -= number; 1471 spin_unlock(&inode->i_lock); 1472 } 1473 EXPORT_SYMBOL(inode_sub_rsv_space); 1474 1475 static qsize_t inode_get_rsv_space(struct inode *inode) 1476 { 1477 qsize_t ret; 1478 1479 if (!inode->i_sb->dq_op->get_reserved_space) 1480 return 0; 1481 spin_lock(&inode->i_lock); 1482 ret = *inode_reserved_space(inode); 1483 spin_unlock(&inode->i_lock); 1484 return ret; 1485 } 1486 1487 static void inode_incr_space(struct inode *inode, qsize_t number, 1488 int reserve) 1489 { 1490 if (reserve) 1491 inode_add_rsv_space(inode, number); 1492 else 1493 inode_add_bytes(inode, number); 1494 } 1495 1496 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1497 { 1498 if (reserve) 1499 inode_sub_rsv_space(inode, number); 1500 else 1501 inode_sub_bytes(inode, number); 1502 } 1503 1504 /* 1505 * This functions updates i_blocks+i_bytes fields and quota information 1506 * (together with appropriate checks). 1507 * 1508 * NOTE: We absolutely rely on the fact that caller dirties the inode 1509 * (usually helpers in quotaops.h care about this) and holds a handle for 1510 * the current transaction so that dquot write and inode write go into the 1511 * same transaction. 1512 */ 1513 1514 /* 1515 * This operation can block, but only after everything is updated 1516 */ 1517 int __dquot_alloc_space(struct inode *inode, qsize_t number, 1518 int warn, int reserve) 1519 { 1520 int cnt, ret = 0; 1521 char warntype[MAXQUOTAS]; 1522 1523 /* 1524 * First test before acquiring mutex - solves deadlocks when we 1525 * re-enter the quota code and are already holding the mutex 1526 */ 1527 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1528 inode_incr_space(inode, number, reserve); 1529 goto out; 1530 } 1531 1532 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1533 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1534 warntype[cnt] = QUOTA_NL_NOWARN; 1535 1536 spin_lock(&dq_data_lock); 1537 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1538 if (!inode->i_dquot[cnt]) 1539 continue; 1540 ret = check_bdq(inode->i_dquot[cnt], number, !warn, 1541 warntype+cnt); 1542 if (ret) { 1543 spin_unlock(&dq_data_lock); 1544 goto out_flush_warn; 1545 } 1546 } 1547 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1548 if (!inode->i_dquot[cnt]) 1549 continue; 1550 if (reserve) 1551 dquot_resv_space(inode->i_dquot[cnt], number); 1552 else 1553 dquot_incr_space(inode->i_dquot[cnt], number); 1554 } 1555 inode_incr_space(inode, number, reserve); 1556 spin_unlock(&dq_data_lock); 1557 1558 if (reserve) 1559 goto out_flush_warn; 1560 mark_all_dquot_dirty(inode->i_dquot); 1561 out_flush_warn: 1562 flush_warnings(inode->i_dquot, warntype); 1563 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1564 out: 1565 return ret; 1566 } 1567 EXPORT_SYMBOL(__dquot_alloc_space); 1568 1569 /* 1570 * This operation can block, but only after everything is updated 1571 */ 1572 int dquot_alloc_inode(const struct inode *inode) 1573 { 1574 int cnt, ret = 0; 1575 char warntype[MAXQUOTAS]; 1576 1577 /* First test before acquiring mutex - solves deadlocks when we 1578 * re-enter the quota code and are already holding the mutex */ 1579 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1580 return 0; 1581 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1582 warntype[cnt] = QUOTA_NL_NOWARN; 1583 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1584 spin_lock(&dq_data_lock); 1585 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1586 if (!inode->i_dquot[cnt]) 1587 continue; 1588 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt); 1589 if (ret) 1590 goto warn_put_all; 1591 } 1592 1593 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1594 if (!inode->i_dquot[cnt]) 1595 continue; 1596 dquot_incr_inodes(inode->i_dquot[cnt], 1); 1597 } 1598 1599 warn_put_all: 1600 spin_unlock(&dq_data_lock); 1601 if (ret == 0) 1602 mark_all_dquot_dirty(inode->i_dquot); 1603 flush_warnings(inode->i_dquot, warntype); 1604 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1605 return ret; 1606 } 1607 EXPORT_SYMBOL(dquot_alloc_inode); 1608 1609 /* 1610 * Convert in-memory reserved quotas to real consumed quotas 1611 */ 1612 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1613 { 1614 int cnt; 1615 1616 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1617 inode_claim_rsv_space(inode, number); 1618 return 0; 1619 } 1620 1621 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1622 spin_lock(&dq_data_lock); 1623 /* Claim reserved quotas to allocated quotas */ 1624 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1625 if (inode->i_dquot[cnt]) 1626 dquot_claim_reserved_space(inode->i_dquot[cnt], 1627 number); 1628 } 1629 /* Update inode bytes */ 1630 inode_claim_rsv_space(inode, number); 1631 spin_unlock(&dq_data_lock); 1632 mark_all_dquot_dirty(inode->i_dquot); 1633 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1634 return 0; 1635 } 1636 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1637 1638 /* 1639 * This operation can block, but only after everything is updated 1640 */ 1641 void __dquot_free_space(struct inode *inode, qsize_t number, int reserve) 1642 { 1643 unsigned int cnt; 1644 char warntype[MAXQUOTAS]; 1645 1646 /* First test before acquiring mutex - solves deadlocks when we 1647 * re-enter the quota code and are already holding the mutex */ 1648 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1649 inode_decr_space(inode, number, reserve); 1650 return; 1651 } 1652 1653 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1654 spin_lock(&dq_data_lock); 1655 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1656 if (!inode->i_dquot[cnt]) 1657 continue; 1658 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1659 if (reserve) 1660 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1661 else 1662 dquot_decr_space(inode->i_dquot[cnt], number); 1663 } 1664 inode_decr_space(inode, number, reserve); 1665 spin_unlock(&dq_data_lock); 1666 1667 if (reserve) 1668 goto out_unlock; 1669 mark_all_dquot_dirty(inode->i_dquot); 1670 out_unlock: 1671 flush_warnings(inode->i_dquot, warntype); 1672 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1673 } 1674 EXPORT_SYMBOL(__dquot_free_space); 1675 1676 /* 1677 * This operation can block, but only after everything is updated 1678 */ 1679 void dquot_free_inode(const struct inode *inode) 1680 { 1681 unsigned int cnt; 1682 char warntype[MAXQUOTAS]; 1683 1684 /* First test before acquiring mutex - solves deadlocks when we 1685 * re-enter the quota code and are already holding the mutex */ 1686 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1687 return; 1688 1689 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1690 spin_lock(&dq_data_lock); 1691 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1692 if (!inode->i_dquot[cnt]) 1693 continue; 1694 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1); 1695 dquot_decr_inodes(inode->i_dquot[cnt], 1); 1696 } 1697 spin_unlock(&dq_data_lock); 1698 mark_all_dquot_dirty(inode->i_dquot); 1699 flush_warnings(inode->i_dquot, warntype); 1700 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1701 } 1702 EXPORT_SYMBOL(dquot_free_inode); 1703 1704 /* 1705 * Transfer the number of inode and blocks from one diskquota to an other. 1706 * On success, dquot references in transfer_to are consumed and references 1707 * to original dquots that need to be released are placed there. On failure, 1708 * references are kept untouched. 1709 * 1710 * This operation can block, but only after everything is updated 1711 * A transaction must be started when entering this function. 1712 * 1713 */ 1714 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1715 { 1716 qsize_t space, cur_space; 1717 qsize_t rsv_space = 0; 1718 struct dquot *transfer_from[MAXQUOTAS] = {}; 1719 int cnt, ret = 0; 1720 char warntype_to[MAXQUOTAS]; 1721 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1722 1723 /* First test before acquiring mutex - solves deadlocks when we 1724 * re-enter the quota code and are already holding the mutex */ 1725 if (IS_NOQUOTA(inode)) 1726 return 0; 1727 /* Initialize the arrays */ 1728 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1729 warntype_to[cnt] = QUOTA_NL_NOWARN; 1730 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1731 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1732 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1733 return 0; 1734 } 1735 spin_lock(&dq_data_lock); 1736 cur_space = inode_get_bytes(inode); 1737 rsv_space = inode_get_rsv_space(inode); 1738 space = cur_space + rsv_space; 1739 /* Build the transfer_from list and check the limits */ 1740 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1741 if (!transfer_to[cnt]) 1742 continue; 1743 transfer_from[cnt] = inode->i_dquot[cnt]; 1744 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt); 1745 if (ret) 1746 goto over_quota; 1747 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt); 1748 if (ret) 1749 goto over_quota; 1750 } 1751 1752 /* 1753 * Finally perform the needed transfer from transfer_from to transfer_to 1754 */ 1755 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1756 /* 1757 * Skip changes for same uid or gid or for turned off quota-type. 1758 */ 1759 if (!transfer_to[cnt]) 1760 continue; 1761 1762 /* Due to IO error we might not have transfer_from[] structure */ 1763 if (transfer_from[cnt]) { 1764 warntype_from_inodes[cnt] = 1765 info_idq_free(transfer_from[cnt], 1); 1766 warntype_from_space[cnt] = 1767 info_bdq_free(transfer_from[cnt], space); 1768 dquot_decr_inodes(transfer_from[cnt], 1); 1769 dquot_decr_space(transfer_from[cnt], cur_space); 1770 dquot_free_reserved_space(transfer_from[cnt], 1771 rsv_space); 1772 } 1773 1774 dquot_incr_inodes(transfer_to[cnt], 1); 1775 dquot_incr_space(transfer_to[cnt], cur_space); 1776 dquot_resv_space(transfer_to[cnt], rsv_space); 1777 1778 inode->i_dquot[cnt] = transfer_to[cnt]; 1779 } 1780 spin_unlock(&dq_data_lock); 1781 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1782 1783 mark_all_dquot_dirty(transfer_from); 1784 mark_all_dquot_dirty(transfer_to); 1785 /* Pass back references to put */ 1786 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1787 transfer_to[cnt] = transfer_from[cnt]; 1788 warn: 1789 flush_warnings(transfer_to, warntype_to); 1790 flush_warnings(transfer_from, warntype_from_inodes); 1791 flush_warnings(transfer_from, warntype_from_space); 1792 return ret; 1793 over_quota: 1794 spin_unlock(&dq_data_lock); 1795 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1796 goto warn; 1797 } 1798 EXPORT_SYMBOL(__dquot_transfer); 1799 1800 /* Wrapper for transferring ownership of an inode for uid/gid only 1801 * Called from FSXXX_setattr() 1802 */ 1803 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1804 { 1805 struct dquot *transfer_to[MAXQUOTAS] = {}; 1806 struct super_block *sb = inode->i_sb; 1807 int ret; 1808 1809 if (!sb_any_quota_active(sb) || IS_NOQUOTA(inode)) 1810 return 0; 1811 1812 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) 1813 transfer_to[USRQUOTA] = dqget(sb, iattr->ia_uid, USRQUOTA); 1814 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) 1815 transfer_to[GRPQUOTA] = dqget(sb, iattr->ia_gid, GRPQUOTA); 1816 1817 ret = __dquot_transfer(inode, transfer_to); 1818 dqput_all(transfer_to); 1819 return ret; 1820 } 1821 EXPORT_SYMBOL(dquot_transfer); 1822 1823 /* 1824 * Write info of quota file to disk 1825 */ 1826 int dquot_commit_info(struct super_block *sb, int type) 1827 { 1828 int ret; 1829 struct quota_info *dqopt = sb_dqopt(sb); 1830 1831 mutex_lock(&dqopt->dqio_mutex); 1832 ret = dqopt->ops[type]->write_file_info(sb, type); 1833 mutex_unlock(&dqopt->dqio_mutex); 1834 return ret; 1835 } 1836 EXPORT_SYMBOL(dquot_commit_info); 1837 1838 /* 1839 * Definitions of diskquota operations. 1840 */ 1841 const struct dquot_operations dquot_operations = { 1842 .write_dquot = dquot_commit, 1843 .acquire_dquot = dquot_acquire, 1844 .release_dquot = dquot_release, 1845 .mark_dirty = dquot_mark_dquot_dirty, 1846 .write_info = dquot_commit_info, 1847 .alloc_dquot = dquot_alloc, 1848 .destroy_dquot = dquot_destroy, 1849 }; 1850 EXPORT_SYMBOL(dquot_operations); 1851 1852 /* 1853 * Generic helper for ->open on filesystems supporting disk quotas. 1854 */ 1855 int dquot_file_open(struct inode *inode, struct file *file) 1856 { 1857 int error; 1858 1859 error = generic_file_open(inode, file); 1860 if (!error && (file->f_mode & FMODE_WRITE)) 1861 dquot_initialize(inode); 1862 return error; 1863 } 1864 EXPORT_SYMBOL(dquot_file_open); 1865 1866 /* 1867 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1868 */ 1869 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 1870 { 1871 int cnt, ret = 0; 1872 struct quota_info *dqopt = sb_dqopt(sb); 1873 struct inode *toputinode[MAXQUOTAS]; 1874 1875 /* Cannot turn off usage accounting without turning off limits, or 1876 * suspend quotas and simultaneously turn quotas off. */ 1877 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1878 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1879 DQUOT_USAGE_ENABLED))) 1880 return -EINVAL; 1881 1882 /* We need to serialize quota_off() for device */ 1883 mutex_lock(&dqopt->dqonoff_mutex); 1884 1885 /* 1886 * Skip everything if there's nothing to do. We have to do this because 1887 * sometimes we are called when fill_super() failed and calling 1888 * sync_fs() in such cases does no good. 1889 */ 1890 if (!sb_any_quota_loaded(sb)) { 1891 mutex_unlock(&dqopt->dqonoff_mutex); 1892 return 0; 1893 } 1894 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1895 toputinode[cnt] = NULL; 1896 if (type != -1 && cnt != type) 1897 continue; 1898 if (!sb_has_quota_loaded(sb, cnt)) 1899 continue; 1900 1901 if (flags & DQUOT_SUSPENDED) { 1902 spin_lock(&dq_state_lock); 1903 dqopt->flags |= 1904 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1905 spin_unlock(&dq_state_lock); 1906 } else { 1907 spin_lock(&dq_state_lock); 1908 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1909 /* Turning off suspended quotas? */ 1910 if (!sb_has_quota_loaded(sb, cnt) && 1911 sb_has_quota_suspended(sb, cnt)) { 1912 dqopt->flags &= ~dquot_state_flag( 1913 DQUOT_SUSPENDED, cnt); 1914 spin_unlock(&dq_state_lock); 1915 iput(dqopt->files[cnt]); 1916 dqopt->files[cnt] = NULL; 1917 continue; 1918 } 1919 spin_unlock(&dq_state_lock); 1920 } 1921 1922 /* We still have to keep quota loaded? */ 1923 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1924 continue; 1925 1926 /* Note: these are blocking operations */ 1927 drop_dquot_ref(sb, cnt); 1928 invalidate_dquots(sb, cnt); 1929 /* 1930 * Now all dquots should be invalidated, all writes done so we 1931 * should be only users of the info. No locks needed. 1932 */ 1933 if (info_dirty(&dqopt->info[cnt])) 1934 sb->dq_op->write_info(sb, cnt); 1935 if (dqopt->ops[cnt]->free_file_info) 1936 dqopt->ops[cnt]->free_file_info(sb, cnt); 1937 put_quota_format(dqopt->info[cnt].dqi_format); 1938 1939 toputinode[cnt] = dqopt->files[cnt]; 1940 if (!sb_has_quota_loaded(sb, cnt)) 1941 dqopt->files[cnt] = NULL; 1942 dqopt->info[cnt].dqi_flags = 0; 1943 dqopt->info[cnt].dqi_igrace = 0; 1944 dqopt->info[cnt].dqi_bgrace = 0; 1945 dqopt->ops[cnt] = NULL; 1946 } 1947 mutex_unlock(&dqopt->dqonoff_mutex); 1948 1949 /* Skip syncing and setting flags if quota files are hidden */ 1950 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1951 goto put_inodes; 1952 1953 /* Sync the superblock so that buffers with quota data are written to 1954 * disk (and so userspace sees correct data afterwards). */ 1955 if (sb->s_op->sync_fs) 1956 sb->s_op->sync_fs(sb, 1); 1957 sync_blockdev(sb->s_bdev); 1958 /* Now the quota files are just ordinary files and we can set the 1959 * inode flags back. Moreover we discard the pagecache so that 1960 * userspace sees the writes we did bypassing the pagecache. We 1961 * must also discard the blockdev buffers so that we see the 1962 * changes done by userspace on the next quotaon() */ 1963 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1964 if (toputinode[cnt]) { 1965 mutex_lock(&dqopt->dqonoff_mutex); 1966 /* If quota was reenabled in the meantime, we have 1967 * nothing to do */ 1968 if (!sb_has_quota_loaded(sb, cnt)) { 1969 mutex_lock_nested(&toputinode[cnt]->i_mutex, 1970 I_MUTEX_QUOTA); 1971 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1972 S_NOATIME | S_NOQUOTA); 1973 truncate_inode_pages(&toputinode[cnt]->i_data, 1974 0); 1975 mutex_unlock(&toputinode[cnt]->i_mutex); 1976 mark_inode_dirty(toputinode[cnt]); 1977 } 1978 mutex_unlock(&dqopt->dqonoff_mutex); 1979 } 1980 if (sb->s_bdev) 1981 invalidate_bdev(sb->s_bdev); 1982 put_inodes: 1983 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1984 if (toputinode[cnt]) { 1985 /* On remount RO, we keep the inode pointer so that we 1986 * can reenable quota on the subsequent remount RW. We 1987 * have to check 'flags' variable and not use sb_has_ 1988 * function because another quotaon / quotaoff could 1989 * change global state before we got here. We refuse 1990 * to suspend quotas when there is pending delete on 1991 * the quota file... */ 1992 if (!(flags & DQUOT_SUSPENDED)) 1993 iput(toputinode[cnt]); 1994 else if (!toputinode[cnt]->i_nlink) 1995 ret = -EBUSY; 1996 } 1997 return ret; 1998 } 1999 EXPORT_SYMBOL(dquot_disable); 2000 2001 int dquot_quota_off(struct super_block *sb, int type) 2002 { 2003 return dquot_disable(sb, type, 2004 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2005 } 2006 EXPORT_SYMBOL(dquot_quota_off); 2007 2008 /* 2009 * Turn quotas on on a device 2010 */ 2011 2012 /* 2013 * Helper function to turn quotas on when we already have the inode of 2014 * quota file and no quota information is loaded. 2015 */ 2016 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2017 unsigned int flags) 2018 { 2019 struct quota_format_type *fmt = find_quota_format(format_id); 2020 struct super_block *sb = inode->i_sb; 2021 struct quota_info *dqopt = sb_dqopt(sb); 2022 int error; 2023 int oldflags = -1; 2024 2025 if (!fmt) 2026 return -ESRCH; 2027 if (!S_ISREG(inode->i_mode)) { 2028 error = -EACCES; 2029 goto out_fmt; 2030 } 2031 if (IS_RDONLY(inode)) { 2032 error = -EROFS; 2033 goto out_fmt; 2034 } 2035 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 2036 error = -EINVAL; 2037 goto out_fmt; 2038 } 2039 /* Usage always has to be set... */ 2040 if (!(flags & DQUOT_USAGE_ENABLED)) { 2041 error = -EINVAL; 2042 goto out_fmt; 2043 } 2044 2045 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2046 /* As we bypass the pagecache we must now flush all the 2047 * dirty data and invalidate caches so that kernel sees 2048 * changes from userspace. It is not enough to just flush 2049 * the quota file since if blocksize < pagesize, invalidation 2050 * of the cache could fail because of other unrelated dirty 2051 * data */ 2052 sync_filesystem(sb); 2053 invalidate_bdev(sb->s_bdev); 2054 } 2055 mutex_lock(&dqopt->dqonoff_mutex); 2056 if (sb_has_quota_loaded(sb, type)) { 2057 error = -EBUSY; 2058 goto out_lock; 2059 } 2060 2061 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2062 /* We don't want quota and atime on quota files (deadlocks 2063 * possible) Also nobody should write to the file - we use 2064 * special IO operations which ignore the immutable bit. */ 2065 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2066 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2067 S_NOQUOTA); 2068 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2069 mutex_unlock(&inode->i_mutex); 2070 /* 2071 * When S_NOQUOTA is set, remove dquot references as no more 2072 * references can be added 2073 */ 2074 __dquot_drop(inode); 2075 } 2076 2077 error = -EIO; 2078 dqopt->files[type] = igrab(inode); 2079 if (!dqopt->files[type]) 2080 goto out_lock; 2081 error = -EINVAL; 2082 if (!fmt->qf_ops->check_quota_file(sb, type)) 2083 goto out_file_init; 2084 2085 dqopt->ops[type] = fmt->qf_ops; 2086 dqopt->info[type].dqi_format = fmt; 2087 dqopt->info[type].dqi_fmt_id = format_id; 2088 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2089 mutex_lock(&dqopt->dqio_mutex); 2090 error = dqopt->ops[type]->read_file_info(sb, type); 2091 if (error < 0) { 2092 mutex_unlock(&dqopt->dqio_mutex); 2093 goto out_file_init; 2094 } 2095 mutex_unlock(&dqopt->dqio_mutex); 2096 spin_lock(&dq_state_lock); 2097 dqopt->flags |= dquot_state_flag(flags, type); 2098 spin_unlock(&dq_state_lock); 2099 2100 add_dquot_ref(sb, type); 2101 mutex_unlock(&dqopt->dqonoff_mutex); 2102 2103 return 0; 2104 2105 out_file_init: 2106 dqopt->files[type] = NULL; 2107 iput(inode); 2108 out_lock: 2109 if (oldflags != -1) { 2110 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2111 /* Set the flags back (in the case of accidental quotaon() 2112 * on a wrong file we don't want to mess up the flags) */ 2113 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2114 inode->i_flags |= oldflags; 2115 mutex_unlock(&inode->i_mutex); 2116 } 2117 mutex_unlock(&dqopt->dqonoff_mutex); 2118 out_fmt: 2119 put_quota_format(fmt); 2120 2121 return error; 2122 } 2123 2124 /* Reenable quotas on remount RW */ 2125 int dquot_resume(struct super_block *sb, int type) 2126 { 2127 struct quota_info *dqopt = sb_dqopt(sb); 2128 struct inode *inode; 2129 int ret = 0, cnt; 2130 unsigned int flags; 2131 2132 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2133 if (type != -1 && cnt != type) 2134 continue; 2135 2136 mutex_lock(&dqopt->dqonoff_mutex); 2137 if (!sb_has_quota_suspended(sb, cnt)) { 2138 mutex_unlock(&dqopt->dqonoff_mutex); 2139 continue; 2140 } 2141 inode = dqopt->files[cnt]; 2142 dqopt->files[cnt] = NULL; 2143 spin_lock(&dq_state_lock); 2144 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2145 DQUOT_LIMITS_ENABLED, 2146 cnt); 2147 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2148 spin_unlock(&dq_state_lock); 2149 mutex_unlock(&dqopt->dqonoff_mutex); 2150 2151 flags = dquot_generic_flag(flags, cnt); 2152 ret = vfs_load_quota_inode(inode, cnt, 2153 dqopt->info[cnt].dqi_fmt_id, flags); 2154 iput(inode); 2155 } 2156 2157 return ret; 2158 } 2159 EXPORT_SYMBOL(dquot_resume); 2160 2161 int dquot_quota_on_path(struct super_block *sb, int type, int format_id, 2162 struct path *path) 2163 { 2164 int error = security_quota_on(path->dentry); 2165 if (error) 2166 return error; 2167 /* Quota file not on the same filesystem? */ 2168 if (path->mnt->mnt_sb != sb) 2169 error = -EXDEV; 2170 else 2171 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2172 format_id, DQUOT_USAGE_ENABLED | 2173 DQUOT_LIMITS_ENABLED); 2174 return error; 2175 } 2176 EXPORT_SYMBOL(dquot_quota_on_path); 2177 2178 int dquot_quota_on(struct super_block *sb, int type, int format_id, char *name) 2179 { 2180 struct path path; 2181 int error; 2182 2183 error = kern_path(name, LOOKUP_FOLLOW, &path); 2184 if (!error) { 2185 error = dquot_quota_on_path(sb, type, format_id, &path); 2186 path_put(&path); 2187 } 2188 return error; 2189 } 2190 EXPORT_SYMBOL(dquot_quota_on); 2191 2192 /* 2193 * More powerful function for turning on quotas allowing setting 2194 * of individual quota flags 2195 */ 2196 int dquot_enable(struct inode *inode, int type, int format_id, 2197 unsigned int flags) 2198 { 2199 int ret = 0; 2200 struct super_block *sb = inode->i_sb; 2201 struct quota_info *dqopt = sb_dqopt(sb); 2202 2203 /* Just unsuspend quotas? */ 2204 BUG_ON(flags & DQUOT_SUSPENDED); 2205 2206 if (!flags) 2207 return 0; 2208 /* Just updating flags needed? */ 2209 if (sb_has_quota_loaded(sb, type)) { 2210 mutex_lock(&dqopt->dqonoff_mutex); 2211 /* Now do a reliable test... */ 2212 if (!sb_has_quota_loaded(sb, type)) { 2213 mutex_unlock(&dqopt->dqonoff_mutex); 2214 goto load_quota; 2215 } 2216 if (flags & DQUOT_USAGE_ENABLED && 2217 sb_has_quota_usage_enabled(sb, type)) { 2218 ret = -EBUSY; 2219 goto out_lock; 2220 } 2221 if (flags & DQUOT_LIMITS_ENABLED && 2222 sb_has_quota_limits_enabled(sb, type)) { 2223 ret = -EBUSY; 2224 goto out_lock; 2225 } 2226 spin_lock(&dq_state_lock); 2227 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2228 spin_unlock(&dq_state_lock); 2229 out_lock: 2230 mutex_unlock(&dqopt->dqonoff_mutex); 2231 return ret; 2232 } 2233 2234 load_quota: 2235 return vfs_load_quota_inode(inode, type, format_id, flags); 2236 } 2237 EXPORT_SYMBOL(dquot_enable); 2238 2239 /* 2240 * This function is used when filesystem needs to initialize quotas 2241 * during mount time. 2242 */ 2243 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2244 int format_id, int type) 2245 { 2246 struct dentry *dentry; 2247 int error; 2248 2249 mutex_lock(&sb->s_root->d_inode->i_mutex); 2250 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2251 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2252 if (IS_ERR(dentry)) 2253 return PTR_ERR(dentry); 2254 2255 if (!dentry->d_inode) { 2256 error = -ENOENT; 2257 goto out; 2258 } 2259 2260 error = security_quota_on(dentry); 2261 if (!error) 2262 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2263 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2264 2265 out: 2266 dput(dentry); 2267 return error; 2268 } 2269 EXPORT_SYMBOL(dquot_quota_on_mount); 2270 2271 static inline qsize_t qbtos(qsize_t blocks) 2272 { 2273 return blocks << QIF_DQBLKSIZE_BITS; 2274 } 2275 2276 static inline qsize_t stoqb(qsize_t space) 2277 { 2278 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2279 } 2280 2281 /* Generic routine for getting common part of quota structure */ 2282 static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2283 { 2284 struct mem_dqblk *dm = &dquot->dq_dqb; 2285 2286 memset(di, 0, sizeof(*di)); 2287 di->d_version = FS_DQUOT_VERSION; 2288 di->d_flags = dquot->dq_type == USRQUOTA ? 2289 XFS_USER_QUOTA : XFS_GROUP_QUOTA; 2290 di->d_id = dquot->dq_id; 2291 2292 spin_lock(&dq_data_lock); 2293 di->d_blk_hardlimit = stoqb(dm->dqb_bhardlimit); 2294 di->d_blk_softlimit = stoqb(dm->dqb_bsoftlimit); 2295 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2296 di->d_ino_softlimit = dm->dqb_isoftlimit; 2297 di->d_bcount = dm->dqb_curspace + dm->dqb_rsvspace; 2298 di->d_icount = dm->dqb_curinodes; 2299 di->d_btimer = dm->dqb_btime; 2300 di->d_itimer = dm->dqb_itime; 2301 spin_unlock(&dq_data_lock); 2302 } 2303 2304 int dquot_get_dqblk(struct super_block *sb, int type, qid_t id, 2305 struct fs_disk_quota *di) 2306 { 2307 struct dquot *dquot; 2308 2309 dquot = dqget(sb, id, type); 2310 if (!dquot) 2311 return -ESRCH; 2312 do_get_dqblk(dquot, di); 2313 dqput(dquot); 2314 2315 return 0; 2316 } 2317 EXPORT_SYMBOL(dquot_get_dqblk); 2318 2319 #define VFS_FS_DQ_MASK \ 2320 (FS_DQ_BCOUNT | FS_DQ_BSOFT | FS_DQ_BHARD | \ 2321 FS_DQ_ICOUNT | FS_DQ_ISOFT | FS_DQ_IHARD | \ 2322 FS_DQ_BTIMER | FS_DQ_ITIMER) 2323 2324 /* Generic routine for setting common part of quota structure */ 2325 static int do_set_dqblk(struct dquot *dquot, struct fs_disk_quota *di) 2326 { 2327 struct mem_dqblk *dm = &dquot->dq_dqb; 2328 int check_blim = 0, check_ilim = 0; 2329 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2330 2331 if (di->d_fieldmask & ~VFS_FS_DQ_MASK) 2332 return -EINVAL; 2333 2334 if (((di->d_fieldmask & FS_DQ_BSOFT) && 2335 (di->d_blk_softlimit > dqi->dqi_maxblimit)) || 2336 ((di->d_fieldmask & FS_DQ_BHARD) && 2337 (di->d_blk_hardlimit > dqi->dqi_maxblimit)) || 2338 ((di->d_fieldmask & FS_DQ_ISOFT) && 2339 (di->d_ino_softlimit > dqi->dqi_maxilimit)) || 2340 ((di->d_fieldmask & FS_DQ_IHARD) && 2341 (di->d_ino_hardlimit > dqi->dqi_maxilimit))) 2342 return -ERANGE; 2343 2344 spin_lock(&dq_data_lock); 2345 if (di->d_fieldmask & FS_DQ_BCOUNT) { 2346 dm->dqb_curspace = di->d_bcount - dm->dqb_rsvspace; 2347 check_blim = 1; 2348 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2349 } 2350 2351 if (di->d_fieldmask & FS_DQ_BSOFT) 2352 dm->dqb_bsoftlimit = qbtos(di->d_blk_softlimit); 2353 if (di->d_fieldmask & FS_DQ_BHARD) 2354 dm->dqb_bhardlimit = qbtos(di->d_blk_hardlimit); 2355 if (di->d_fieldmask & (FS_DQ_BSOFT | FS_DQ_BHARD)) { 2356 check_blim = 1; 2357 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2358 } 2359 2360 if (di->d_fieldmask & FS_DQ_ICOUNT) { 2361 dm->dqb_curinodes = di->d_icount; 2362 check_ilim = 1; 2363 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2364 } 2365 2366 if (di->d_fieldmask & FS_DQ_ISOFT) 2367 dm->dqb_isoftlimit = di->d_ino_softlimit; 2368 if (di->d_fieldmask & FS_DQ_IHARD) 2369 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2370 if (di->d_fieldmask & (FS_DQ_ISOFT | FS_DQ_IHARD)) { 2371 check_ilim = 1; 2372 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2373 } 2374 2375 if (di->d_fieldmask & FS_DQ_BTIMER) { 2376 dm->dqb_btime = di->d_btimer; 2377 check_blim = 1; 2378 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2379 } 2380 2381 if (di->d_fieldmask & FS_DQ_ITIMER) { 2382 dm->dqb_itime = di->d_itimer; 2383 check_ilim = 1; 2384 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2385 } 2386 2387 if (check_blim) { 2388 if (!dm->dqb_bsoftlimit || 2389 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2390 dm->dqb_btime = 0; 2391 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2392 } else if (!(di->d_fieldmask & FS_DQ_BTIMER)) 2393 /* Set grace only if user hasn't provided his own... */ 2394 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2395 } 2396 if (check_ilim) { 2397 if (!dm->dqb_isoftlimit || 2398 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2399 dm->dqb_itime = 0; 2400 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2401 } else if (!(di->d_fieldmask & FS_DQ_ITIMER)) 2402 /* Set grace only if user hasn't provided his own... */ 2403 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2404 } 2405 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2406 dm->dqb_isoftlimit) 2407 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2408 else 2409 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2410 spin_unlock(&dq_data_lock); 2411 mark_dquot_dirty(dquot); 2412 2413 return 0; 2414 } 2415 2416 int dquot_set_dqblk(struct super_block *sb, int type, qid_t id, 2417 struct fs_disk_quota *di) 2418 { 2419 struct dquot *dquot; 2420 int rc; 2421 2422 dquot = dqget(sb, id, type); 2423 if (!dquot) { 2424 rc = -ESRCH; 2425 goto out; 2426 } 2427 rc = do_set_dqblk(dquot, di); 2428 dqput(dquot); 2429 out: 2430 return rc; 2431 } 2432 EXPORT_SYMBOL(dquot_set_dqblk); 2433 2434 /* Generic routine for getting common part of quota file information */ 2435 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2436 { 2437 struct mem_dqinfo *mi; 2438 2439 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2440 if (!sb_has_quota_active(sb, type)) { 2441 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2442 return -ESRCH; 2443 } 2444 mi = sb_dqopt(sb)->info + type; 2445 spin_lock(&dq_data_lock); 2446 ii->dqi_bgrace = mi->dqi_bgrace; 2447 ii->dqi_igrace = mi->dqi_igrace; 2448 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 2449 ii->dqi_valid = IIF_ALL; 2450 spin_unlock(&dq_data_lock); 2451 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2452 return 0; 2453 } 2454 EXPORT_SYMBOL(dquot_get_dqinfo); 2455 2456 /* Generic routine for setting common part of quota file information */ 2457 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2458 { 2459 struct mem_dqinfo *mi; 2460 int err = 0; 2461 2462 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2463 if (!sb_has_quota_active(sb, type)) { 2464 err = -ESRCH; 2465 goto out; 2466 } 2467 mi = sb_dqopt(sb)->info + type; 2468 spin_lock(&dq_data_lock); 2469 if (ii->dqi_valid & IIF_BGRACE) 2470 mi->dqi_bgrace = ii->dqi_bgrace; 2471 if (ii->dqi_valid & IIF_IGRACE) 2472 mi->dqi_igrace = ii->dqi_igrace; 2473 if (ii->dqi_valid & IIF_FLAGS) 2474 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | 2475 (ii->dqi_flags & DQF_MASK); 2476 spin_unlock(&dq_data_lock); 2477 mark_info_dirty(sb, type); 2478 /* Force write to disk */ 2479 sb->dq_op->write_info(sb, type); 2480 out: 2481 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2482 return err; 2483 } 2484 EXPORT_SYMBOL(dquot_set_dqinfo); 2485 2486 const struct quotactl_ops dquot_quotactl_ops = { 2487 .quota_on = dquot_quota_on, 2488 .quota_off = dquot_quota_off, 2489 .quota_sync = dquot_quota_sync, 2490 .get_info = dquot_get_dqinfo, 2491 .set_info = dquot_set_dqinfo, 2492 .get_dqblk = dquot_get_dqblk, 2493 .set_dqblk = dquot_set_dqblk 2494 }; 2495 EXPORT_SYMBOL(dquot_quotactl_ops); 2496 2497 static int do_proc_dqstats(struct ctl_table *table, int write, 2498 void __user *buffer, size_t *lenp, loff_t *ppos) 2499 { 2500 #ifdef CONFIG_SMP 2501 /* Update global table */ 2502 unsigned int type = (int *)table->data - dqstats.stat; 2503 dqstats.stat[type] = dqstats_read(type); 2504 #endif 2505 return proc_dointvec(table, write, buffer, lenp, ppos); 2506 } 2507 2508 static ctl_table fs_dqstats_table[] = { 2509 { 2510 .procname = "lookups", 2511 .data = &dqstats.stat[DQST_LOOKUPS], 2512 .maxlen = sizeof(int), 2513 .mode = 0444, 2514 .proc_handler = do_proc_dqstats, 2515 }, 2516 { 2517 .procname = "drops", 2518 .data = &dqstats.stat[DQST_DROPS], 2519 .maxlen = sizeof(int), 2520 .mode = 0444, 2521 .proc_handler = do_proc_dqstats, 2522 }, 2523 { 2524 .procname = "reads", 2525 .data = &dqstats.stat[DQST_READS], 2526 .maxlen = sizeof(int), 2527 .mode = 0444, 2528 .proc_handler = do_proc_dqstats, 2529 }, 2530 { 2531 .procname = "writes", 2532 .data = &dqstats.stat[DQST_WRITES], 2533 .maxlen = sizeof(int), 2534 .mode = 0444, 2535 .proc_handler = do_proc_dqstats, 2536 }, 2537 { 2538 .procname = "cache_hits", 2539 .data = &dqstats.stat[DQST_CACHE_HITS], 2540 .maxlen = sizeof(int), 2541 .mode = 0444, 2542 .proc_handler = do_proc_dqstats, 2543 }, 2544 { 2545 .procname = "allocated_dquots", 2546 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2547 .maxlen = sizeof(int), 2548 .mode = 0444, 2549 .proc_handler = do_proc_dqstats, 2550 }, 2551 { 2552 .procname = "free_dquots", 2553 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2554 .maxlen = sizeof(int), 2555 .mode = 0444, 2556 .proc_handler = do_proc_dqstats, 2557 }, 2558 { 2559 .procname = "syncs", 2560 .data = &dqstats.stat[DQST_SYNCS], 2561 .maxlen = sizeof(int), 2562 .mode = 0444, 2563 .proc_handler = do_proc_dqstats, 2564 }, 2565 #ifdef CONFIG_PRINT_QUOTA_WARNING 2566 { 2567 .procname = "warnings", 2568 .data = &flag_print_warnings, 2569 .maxlen = sizeof(int), 2570 .mode = 0644, 2571 .proc_handler = proc_dointvec, 2572 }, 2573 #endif 2574 { }, 2575 }; 2576 2577 static ctl_table fs_table[] = { 2578 { 2579 .procname = "quota", 2580 .mode = 0555, 2581 .child = fs_dqstats_table, 2582 }, 2583 { }, 2584 }; 2585 2586 static ctl_table sys_table[] = { 2587 { 2588 .procname = "fs", 2589 .mode = 0555, 2590 .child = fs_table, 2591 }, 2592 { }, 2593 }; 2594 2595 static int __init dquot_init(void) 2596 { 2597 int i; 2598 unsigned long nr_hash, order; 2599 2600 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2601 2602 register_sysctl_table(sys_table); 2603 2604 dquot_cachep = kmem_cache_create("dquot", 2605 sizeof(struct dquot), sizeof(unsigned long) * 4, 2606 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2607 SLAB_MEM_SPREAD|SLAB_PANIC), 2608 NULL); 2609 2610 order = 0; 2611 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2612 if (!dquot_hash) 2613 panic("Cannot create dquot hash table"); 2614 2615 #ifdef CONFIG_SMP 2616 dqstats_pcpu = alloc_percpu(struct dqstats); 2617 if (!dqstats_pcpu) 2618 panic("Cannot create dquot stats table"); 2619 #endif 2620 memset(&dqstats, 0, sizeof(struct dqstats)); 2621 2622 /* Find power-of-two hlist_heads which can fit into allocation */ 2623 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2624 dq_hash_bits = 0; 2625 do { 2626 dq_hash_bits++; 2627 } while (nr_hash >> dq_hash_bits); 2628 dq_hash_bits--; 2629 2630 nr_hash = 1UL << dq_hash_bits; 2631 dq_hash_mask = nr_hash - 1; 2632 for (i = 0; i < nr_hash; i++) 2633 INIT_HLIST_HEAD(dquot_hash + i); 2634 2635 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2636 nr_hash, order, (PAGE_SIZE << order)); 2637 2638 register_shrinker(&dqcache_shrinker); 2639 2640 return 0; 2641 } 2642 module_init(dquot_init); 2643