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 #define __DQUOT_PARANOIA 84 85 /* 86 * There are three quota SMP locks. dq_list_lock protects all lists with quotas 87 * and quota formats, dqstats structure containing statistics about the lists 88 * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and 89 * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes. 90 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly 91 * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects 92 * modifications of quota state (on quotaon and quotaoff) and readers who care 93 * about latest values take it as well. 94 * 95 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock, 96 * dq_list_lock > dq_state_lock 97 * 98 * Note that some things (eg. sb pointer, type, id) doesn't change during 99 * the life of the dquot structure and so needn't to be protected by a lock 100 * 101 * Any operation working on dquots via inode pointers must hold dqptr_sem. If 102 * operation is just reading pointers from inode (or not using them at all) the 103 * read lock is enough. If pointers are altered function must hold write lock. 104 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 105 * inode is a quota file). Functions adding pointers from inode to dquots have 106 * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they 107 * have to do all pointer modifications before dropping dqptr_sem. This makes 108 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 109 * then drops all pointers to dquots from an inode. 110 * 111 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced 112 * from inodes (dquot_alloc_space() and such don't check the dq_lock). 113 * Currently dquot is locked only when it is being read to memory (or space for 114 * it is being allocated) on the first dqget() and when it is being released on 115 * the last dqput(). The allocation and release oparations are serialized by 116 * the dq_lock and by checking the use count in dquot_release(). Write 117 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock 118 * spinlock to internal buffers before writing. 119 * 120 * Lock ordering (including related VFS locks) is the following: 121 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > 122 * dqio_mutex 123 * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem > 124 * dqptr_sem. But filesystem has to count with the fact that functions such as 125 * dquot_alloc_space() acquire dqptr_sem and they usually have to be called 126 * from inside a transaction to keep filesystem consistency after a crash. Also 127 * filesystems usually want to do some IO on dquot from ->mark_dirty which is 128 * called with dqptr_sem held. 129 * i_mutex on quota files is special (it's below dqio_mutex) 130 */ 131 132 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 133 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 134 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 135 EXPORT_SYMBOL(dq_data_lock); 136 137 static char *quotatypes[] = INITQFNAMES; 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); 231 232 static qsize_t inode_get_rsv_space(struct inode *inode); 233 234 static inline unsigned int 235 hashfn(const struct super_block *sb, unsigned int id, int type) 236 { 237 unsigned long tmp; 238 239 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 240 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 241 } 242 243 /* 244 * Following list functions expect dq_list_lock to be held 245 */ 246 static inline void insert_dquot_hash(struct dquot *dquot) 247 { 248 struct hlist_head *head; 249 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 250 hlist_add_head(&dquot->dq_hash, head); 251 } 252 253 static inline void remove_dquot_hash(struct dquot *dquot) 254 { 255 hlist_del_init(&dquot->dq_hash); 256 } 257 258 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 259 unsigned int id, int type) 260 { 261 struct hlist_node *node; 262 struct dquot *dquot; 263 264 hlist_for_each (node, dquot_hash+hashent) { 265 dquot = hlist_entry(node, struct dquot, dq_hash); 266 if (dquot->dq_sb == sb && dquot->dq_id == id && 267 dquot->dq_type == type) 268 return dquot; 269 } 270 return NULL; 271 } 272 273 /* Add a dquot to the tail of the free list */ 274 static inline void put_dquot_last(struct dquot *dquot) 275 { 276 list_add_tail(&dquot->dq_free, &free_dquots); 277 dqstats.free_dquots++; 278 } 279 280 static inline void remove_free_dquot(struct dquot *dquot) 281 { 282 if (list_empty(&dquot->dq_free)) 283 return; 284 list_del_init(&dquot->dq_free); 285 dqstats.free_dquots--; 286 } 287 288 static inline void put_inuse(struct dquot *dquot) 289 { 290 /* We add to the back of inuse list so we don't have to restart 291 * when traversing this list and we block */ 292 list_add_tail(&dquot->dq_inuse, &inuse_list); 293 dqstats.allocated_dquots++; 294 } 295 296 static inline void remove_inuse(struct dquot *dquot) 297 { 298 dqstats.allocated_dquots--; 299 list_del(&dquot->dq_inuse); 300 } 301 /* 302 * End of list functions needing dq_list_lock 303 */ 304 305 static void wait_on_dquot(struct dquot *dquot) 306 { 307 mutex_lock(&dquot->dq_lock); 308 mutex_unlock(&dquot->dq_lock); 309 } 310 311 static inline int dquot_dirty(struct dquot *dquot) 312 { 313 return test_bit(DQ_MOD_B, &dquot->dq_flags); 314 } 315 316 static inline int mark_dquot_dirty(struct dquot *dquot) 317 { 318 return dquot->dq_sb->dq_op->mark_dirty(dquot); 319 } 320 321 int dquot_mark_dquot_dirty(struct dquot *dquot) 322 { 323 spin_lock(&dq_list_lock); 324 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) 325 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 326 info[dquot->dq_type].dqi_dirty_list); 327 spin_unlock(&dq_list_lock); 328 return 0; 329 } 330 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 331 332 /* Dirtify all the dquots - this can block when journalling */ 333 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 334 { 335 int ret, err, cnt; 336 337 ret = err = 0; 338 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 339 if (dquot[cnt]) 340 /* Even in case of error we have to continue */ 341 ret = mark_dquot_dirty(dquot[cnt]); 342 if (!err) 343 err = ret; 344 } 345 return err; 346 } 347 348 static inline void dqput_all(struct dquot **dquot) 349 { 350 unsigned int cnt; 351 352 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 353 dqput(dquot[cnt]); 354 } 355 356 /* This function needs dq_list_lock */ 357 static inline int clear_dquot_dirty(struct dquot *dquot) 358 { 359 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 360 return 0; 361 list_del_init(&dquot->dq_dirty); 362 return 1; 363 } 364 365 void mark_info_dirty(struct super_block *sb, int type) 366 { 367 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 368 } 369 EXPORT_SYMBOL(mark_info_dirty); 370 371 /* 372 * Read dquot from disk and alloc space for it 373 */ 374 375 int dquot_acquire(struct dquot *dquot) 376 { 377 int ret = 0, ret2 = 0; 378 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 379 380 mutex_lock(&dquot->dq_lock); 381 mutex_lock(&dqopt->dqio_mutex); 382 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 383 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 384 if (ret < 0) 385 goto out_iolock; 386 set_bit(DQ_READ_B, &dquot->dq_flags); 387 /* Instantiate dquot if needed */ 388 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 389 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 390 /* Write the info if needed */ 391 if (info_dirty(&dqopt->info[dquot->dq_type])) { 392 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 393 dquot->dq_sb, dquot->dq_type); 394 } 395 if (ret < 0) 396 goto out_iolock; 397 if (ret2 < 0) { 398 ret = ret2; 399 goto out_iolock; 400 } 401 } 402 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 403 out_iolock: 404 mutex_unlock(&dqopt->dqio_mutex); 405 mutex_unlock(&dquot->dq_lock); 406 return ret; 407 } 408 EXPORT_SYMBOL(dquot_acquire); 409 410 /* 411 * Write dquot to disk 412 */ 413 int dquot_commit(struct dquot *dquot) 414 { 415 int ret = 0, ret2 = 0; 416 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 417 418 mutex_lock(&dqopt->dqio_mutex); 419 spin_lock(&dq_list_lock); 420 if (!clear_dquot_dirty(dquot)) { 421 spin_unlock(&dq_list_lock); 422 goto out_sem; 423 } 424 spin_unlock(&dq_list_lock); 425 /* Inactive dquot can be only if there was error during read/init 426 * => we have better not writing it */ 427 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 428 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 429 if (info_dirty(&dqopt->info[dquot->dq_type])) { 430 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 431 dquot->dq_sb, dquot->dq_type); 432 } 433 if (ret >= 0) 434 ret = ret2; 435 } 436 out_sem: 437 mutex_unlock(&dqopt->dqio_mutex); 438 return ret; 439 } 440 EXPORT_SYMBOL(dquot_commit); 441 442 /* 443 * Release dquot 444 */ 445 int dquot_release(struct dquot *dquot) 446 { 447 int ret = 0, ret2 = 0; 448 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 449 450 mutex_lock(&dquot->dq_lock); 451 /* Check whether we are not racing with some other dqget() */ 452 if (atomic_read(&dquot->dq_count) > 1) 453 goto out_dqlock; 454 mutex_lock(&dqopt->dqio_mutex); 455 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 456 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 457 /* Write the info */ 458 if (info_dirty(&dqopt->info[dquot->dq_type])) { 459 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 460 dquot->dq_sb, dquot->dq_type); 461 } 462 if (ret >= 0) 463 ret = ret2; 464 } 465 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 466 mutex_unlock(&dqopt->dqio_mutex); 467 out_dqlock: 468 mutex_unlock(&dquot->dq_lock); 469 return ret; 470 } 471 EXPORT_SYMBOL(dquot_release); 472 473 void dquot_destroy(struct dquot *dquot) 474 { 475 kmem_cache_free(dquot_cachep, dquot); 476 } 477 EXPORT_SYMBOL(dquot_destroy); 478 479 static inline void do_destroy_dquot(struct dquot *dquot) 480 { 481 dquot->dq_sb->dq_op->destroy_dquot(dquot); 482 } 483 484 /* Invalidate all dquots on the list. Note that this function is called after 485 * quota is disabled and pointers from inodes removed so there cannot be new 486 * quota users. There can still be some users of quotas due to inodes being 487 * just deleted or pruned by prune_icache() (those are not attached to any 488 * list) or parallel quotactl call. We have to wait for such users. 489 */ 490 static void invalidate_dquots(struct super_block *sb, int type) 491 { 492 struct dquot *dquot, *tmp; 493 494 restart: 495 spin_lock(&dq_list_lock); 496 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 497 if (dquot->dq_sb != sb) 498 continue; 499 if (dquot->dq_type != type) 500 continue; 501 /* Wait for dquot users */ 502 if (atomic_read(&dquot->dq_count)) { 503 DEFINE_WAIT(wait); 504 505 atomic_inc(&dquot->dq_count); 506 prepare_to_wait(&dquot->dq_wait_unused, &wait, 507 TASK_UNINTERRUPTIBLE); 508 spin_unlock(&dq_list_lock); 509 /* Once dqput() wakes us up, we know it's time to free 510 * the dquot. 511 * IMPORTANT: we rely on the fact that there is always 512 * at most one process waiting for dquot to free. 513 * Otherwise dq_count would be > 1 and we would never 514 * wake up. 515 */ 516 if (atomic_read(&dquot->dq_count) > 1) 517 schedule(); 518 finish_wait(&dquot->dq_wait_unused, &wait); 519 dqput(dquot); 520 /* At this moment dquot() need not exist (it could be 521 * reclaimed by prune_dqcache(). Hence we must 522 * restart. */ 523 goto restart; 524 } 525 /* 526 * Quota now has no users and it has been written on last 527 * dqput() 528 */ 529 remove_dquot_hash(dquot); 530 remove_free_dquot(dquot); 531 remove_inuse(dquot); 532 do_destroy_dquot(dquot); 533 } 534 spin_unlock(&dq_list_lock); 535 } 536 537 /* Call callback for every active dquot on given filesystem */ 538 int dquot_scan_active(struct super_block *sb, 539 int (*fn)(struct dquot *dquot, unsigned long priv), 540 unsigned long priv) 541 { 542 struct dquot *dquot, *old_dquot = NULL; 543 int ret = 0; 544 545 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 546 spin_lock(&dq_list_lock); 547 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 548 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 549 continue; 550 if (dquot->dq_sb != sb) 551 continue; 552 /* Now we have active dquot so we can just increase use count */ 553 atomic_inc(&dquot->dq_count); 554 dqstats.lookups++; 555 spin_unlock(&dq_list_lock); 556 dqput(old_dquot); 557 old_dquot = dquot; 558 ret = fn(dquot, priv); 559 if (ret < 0) 560 goto out; 561 spin_lock(&dq_list_lock); 562 /* We are safe to continue now because our dquot could not 563 * be moved out of the inuse list while we hold the reference */ 564 } 565 spin_unlock(&dq_list_lock); 566 out: 567 dqput(old_dquot); 568 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 569 return ret; 570 } 571 EXPORT_SYMBOL(dquot_scan_active); 572 573 int vfs_quota_sync(struct super_block *sb, int type) 574 { 575 struct list_head *dirty; 576 struct dquot *dquot; 577 struct quota_info *dqopt = sb_dqopt(sb); 578 int cnt; 579 580 mutex_lock(&dqopt->dqonoff_mutex); 581 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 582 if (type != -1 && cnt != type) 583 continue; 584 if (!sb_has_quota_active(sb, cnt)) 585 continue; 586 spin_lock(&dq_list_lock); 587 dirty = &dqopt->info[cnt].dqi_dirty_list; 588 while (!list_empty(dirty)) { 589 dquot = list_first_entry(dirty, struct dquot, 590 dq_dirty); 591 /* Dirty and inactive can be only bad dquot... */ 592 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 593 clear_dquot_dirty(dquot); 594 continue; 595 } 596 /* Now we have active dquot from which someone is 597 * holding reference so we can safely just increase 598 * use count */ 599 atomic_inc(&dquot->dq_count); 600 dqstats.lookups++; 601 spin_unlock(&dq_list_lock); 602 sb->dq_op->write_dquot(dquot); 603 dqput(dquot); 604 spin_lock(&dq_list_lock); 605 } 606 spin_unlock(&dq_list_lock); 607 } 608 609 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 610 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 611 && info_dirty(&dqopt->info[cnt])) 612 sb->dq_op->write_info(sb, cnt); 613 spin_lock(&dq_list_lock); 614 dqstats.syncs++; 615 spin_unlock(&dq_list_lock); 616 mutex_unlock(&dqopt->dqonoff_mutex); 617 618 return 0; 619 } 620 EXPORT_SYMBOL(vfs_quota_sync); 621 622 /* Free unused dquots from cache */ 623 static void prune_dqcache(int count) 624 { 625 struct list_head *head; 626 struct dquot *dquot; 627 628 head = free_dquots.prev; 629 while (head != &free_dquots && count) { 630 dquot = list_entry(head, struct dquot, dq_free); 631 remove_dquot_hash(dquot); 632 remove_free_dquot(dquot); 633 remove_inuse(dquot); 634 do_destroy_dquot(dquot); 635 count--; 636 head = free_dquots.prev; 637 } 638 } 639 640 /* 641 * This is called from kswapd when we think we need some 642 * more memory 643 */ 644 645 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 646 { 647 if (nr) { 648 spin_lock(&dq_list_lock); 649 prune_dqcache(nr); 650 spin_unlock(&dq_list_lock); 651 } 652 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure; 653 } 654 655 static struct shrinker dqcache_shrinker = { 656 .shrink = shrink_dqcache_memory, 657 .seeks = DEFAULT_SEEKS, 658 }; 659 660 /* 661 * Put reference to dquot 662 * NOTE: If you change this function please check whether dqput_blocks() works right... 663 */ 664 void dqput(struct dquot *dquot) 665 { 666 int ret; 667 668 if (!dquot) 669 return; 670 #ifdef __DQUOT_PARANOIA 671 if (!atomic_read(&dquot->dq_count)) { 672 printk("VFS: dqput: trying to free free dquot\n"); 673 printk("VFS: device %s, dquot of %s %d\n", 674 dquot->dq_sb->s_id, 675 quotatypes[dquot->dq_type], 676 dquot->dq_id); 677 BUG(); 678 } 679 #endif 680 681 spin_lock(&dq_list_lock); 682 dqstats.drops++; 683 spin_unlock(&dq_list_lock); 684 we_slept: 685 spin_lock(&dq_list_lock); 686 if (atomic_read(&dquot->dq_count) > 1) { 687 /* We have more than one user... nothing to do */ 688 atomic_dec(&dquot->dq_count); 689 /* Releasing dquot during quotaoff phase? */ 690 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 691 atomic_read(&dquot->dq_count) == 1) 692 wake_up(&dquot->dq_wait_unused); 693 spin_unlock(&dq_list_lock); 694 return; 695 } 696 /* Need to release dquot? */ 697 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 698 spin_unlock(&dq_list_lock); 699 /* Commit dquot before releasing */ 700 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 701 if (ret < 0) { 702 printk(KERN_ERR "VFS: cannot write quota structure on " 703 "device %s (error %d). Quota may get out of " 704 "sync!\n", dquot->dq_sb->s_id, ret); 705 /* 706 * We clear dirty bit anyway, so that we avoid 707 * infinite loop here 708 */ 709 spin_lock(&dq_list_lock); 710 clear_dquot_dirty(dquot); 711 spin_unlock(&dq_list_lock); 712 } 713 goto we_slept; 714 } 715 /* Clear flag in case dquot was inactive (something bad happened) */ 716 clear_dquot_dirty(dquot); 717 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 718 spin_unlock(&dq_list_lock); 719 dquot->dq_sb->dq_op->release_dquot(dquot); 720 goto we_slept; 721 } 722 atomic_dec(&dquot->dq_count); 723 #ifdef __DQUOT_PARANOIA 724 /* sanity check */ 725 BUG_ON(!list_empty(&dquot->dq_free)); 726 #endif 727 put_dquot_last(dquot); 728 spin_unlock(&dq_list_lock); 729 } 730 EXPORT_SYMBOL(dqput); 731 732 struct dquot *dquot_alloc(struct super_block *sb, int type) 733 { 734 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 735 } 736 EXPORT_SYMBOL(dquot_alloc); 737 738 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 739 { 740 struct dquot *dquot; 741 742 dquot = sb->dq_op->alloc_dquot(sb, type); 743 if(!dquot) 744 return NULL; 745 746 mutex_init(&dquot->dq_lock); 747 INIT_LIST_HEAD(&dquot->dq_free); 748 INIT_LIST_HEAD(&dquot->dq_inuse); 749 INIT_HLIST_NODE(&dquot->dq_hash); 750 INIT_LIST_HEAD(&dquot->dq_dirty); 751 init_waitqueue_head(&dquot->dq_wait_unused); 752 dquot->dq_sb = sb; 753 dquot->dq_type = type; 754 atomic_set(&dquot->dq_count, 1); 755 756 return dquot; 757 } 758 759 /* 760 * Get reference to dquot 761 * 762 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 763 * destroying our dquot by: 764 * a) checking for quota flags under dq_list_lock and 765 * b) getting a reference to dquot before we release dq_list_lock 766 */ 767 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 768 { 769 unsigned int hashent = hashfn(sb, id, type); 770 struct dquot *dquot = NULL, *empty = NULL; 771 772 if (!sb_has_quota_active(sb, type)) 773 return NULL; 774 we_slept: 775 spin_lock(&dq_list_lock); 776 spin_lock(&dq_state_lock); 777 if (!sb_has_quota_active(sb, type)) { 778 spin_unlock(&dq_state_lock); 779 spin_unlock(&dq_list_lock); 780 goto out; 781 } 782 spin_unlock(&dq_state_lock); 783 784 dquot = find_dquot(hashent, sb, id, type); 785 if (!dquot) { 786 if (!empty) { 787 spin_unlock(&dq_list_lock); 788 empty = get_empty_dquot(sb, type); 789 if (!empty) 790 schedule(); /* Try to wait for a moment... */ 791 goto we_slept; 792 } 793 dquot = empty; 794 empty = NULL; 795 dquot->dq_id = id; 796 /* all dquots go on the inuse_list */ 797 put_inuse(dquot); 798 /* hash it first so it can be found */ 799 insert_dquot_hash(dquot); 800 dqstats.lookups++; 801 spin_unlock(&dq_list_lock); 802 } else { 803 if (!atomic_read(&dquot->dq_count)) 804 remove_free_dquot(dquot); 805 atomic_inc(&dquot->dq_count); 806 dqstats.cache_hits++; 807 dqstats.lookups++; 808 spin_unlock(&dq_list_lock); 809 } 810 /* Wait for dq_lock - after this we know that either dquot_release() is 811 * already finished or it will be canceled due to dq_count > 1 test */ 812 wait_on_dquot(dquot); 813 /* Read the dquot / allocate space in quota file */ 814 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 815 sb->dq_op->acquire_dquot(dquot) < 0) { 816 dqput(dquot); 817 dquot = NULL; 818 goto out; 819 } 820 #ifdef __DQUOT_PARANOIA 821 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 822 #endif 823 out: 824 if (empty) 825 do_destroy_dquot(empty); 826 827 return dquot; 828 } 829 EXPORT_SYMBOL(dqget); 830 831 static int dqinit_needed(struct inode *inode, int type) 832 { 833 int cnt; 834 835 if (IS_NOQUOTA(inode)) 836 return 0; 837 if (type != -1) 838 return !inode->i_dquot[type]; 839 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 840 if (!inode->i_dquot[cnt]) 841 return 1; 842 return 0; 843 } 844 845 /* This routine is guarded by dqonoff_mutex mutex */ 846 static void add_dquot_ref(struct super_block *sb, int type) 847 { 848 struct inode *inode, *old_inode = NULL; 849 int reserved = 0; 850 851 spin_lock(&inode_lock); 852 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 853 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) 854 continue; 855 if (unlikely(inode_get_rsv_space(inode) > 0)) 856 reserved = 1; 857 if (!atomic_read(&inode->i_writecount)) 858 continue; 859 if (!dqinit_needed(inode, type)) 860 continue; 861 862 __iget(inode); 863 spin_unlock(&inode_lock); 864 865 iput(old_inode); 866 sb->dq_op->initialize(inode, type); 867 /* We hold a reference to 'inode' so it couldn't have been 868 * removed from s_inodes list while we dropped the inode_lock. 869 * We cannot iput the inode now as we can be holding the last 870 * reference and we cannot iput it under inode_lock. So we 871 * keep the reference and iput it later. */ 872 old_inode = inode; 873 spin_lock(&inode_lock); 874 } 875 spin_unlock(&inode_lock); 876 iput(old_inode); 877 878 if (reserved) { 879 printk(KERN_WARNING "VFS (%s): Writes happened before quota" 880 " was turned on thus quota information is probably " 881 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 882 } 883 } 884 885 /* 886 * Return 0 if dqput() won't block. 887 * (note that 1 doesn't necessarily mean blocking) 888 */ 889 static inline int dqput_blocks(struct dquot *dquot) 890 { 891 if (atomic_read(&dquot->dq_count) <= 1) 892 return 1; 893 return 0; 894 } 895 896 /* 897 * Remove references to dquots from inode and add dquot to list for freeing 898 * if we have the last referece to dquot 899 * We can't race with anybody because we hold dqptr_sem for writing... 900 */ 901 static int remove_inode_dquot_ref(struct inode *inode, int type, 902 struct list_head *tofree_head) 903 { 904 struct dquot *dquot = inode->i_dquot[type]; 905 906 inode->i_dquot[type] = NULL; 907 if (dquot) { 908 if (dqput_blocks(dquot)) { 909 #ifdef __DQUOT_PARANOIA 910 if (atomic_read(&dquot->dq_count) != 1) 911 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); 912 #endif 913 spin_lock(&dq_list_lock); 914 /* As dquot must have currently users it can't be on 915 * the free list... */ 916 list_add(&dquot->dq_free, tofree_head); 917 spin_unlock(&dq_list_lock); 918 return 1; 919 } 920 else 921 dqput(dquot); /* We have guaranteed we won't block */ 922 } 923 return 0; 924 } 925 926 /* 927 * Free list of dquots 928 * Dquots are removed from inodes and no new references can be got so we are 929 * the only ones holding reference 930 */ 931 static void put_dquot_list(struct list_head *tofree_head) 932 { 933 struct list_head *act_head; 934 struct dquot *dquot; 935 936 act_head = tofree_head->next; 937 while (act_head != tofree_head) { 938 dquot = list_entry(act_head, struct dquot, dq_free); 939 act_head = act_head->next; 940 /* Remove dquot from the list so we won't have problems... */ 941 list_del_init(&dquot->dq_free); 942 dqput(dquot); 943 } 944 } 945 946 static void remove_dquot_ref(struct super_block *sb, int type, 947 struct list_head *tofree_head) 948 { 949 struct inode *inode; 950 951 spin_lock(&inode_lock); 952 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 953 /* 954 * We have to scan also I_NEW inodes because they can already 955 * have quota pointer initialized. Luckily, we need to touch 956 * only quota pointers and these have separate locking 957 * (dqptr_sem). 958 */ 959 if (!IS_NOQUOTA(inode)) 960 remove_inode_dquot_ref(inode, type, tofree_head); 961 } 962 spin_unlock(&inode_lock); 963 } 964 965 /* Gather all references from inodes and drop them */ 966 static void drop_dquot_ref(struct super_block *sb, int type) 967 { 968 LIST_HEAD(tofree_head); 969 970 if (sb->dq_op) { 971 down_write(&sb_dqopt(sb)->dqptr_sem); 972 remove_dquot_ref(sb, type, &tofree_head); 973 up_write(&sb_dqopt(sb)->dqptr_sem); 974 put_dquot_list(&tofree_head); 975 } 976 } 977 978 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 979 { 980 dquot->dq_dqb.dqb_curinodes += number; 981 } 982 983 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 984 { 985 dquot->dq_dqb.dqb_curspace += number; 986 } 987 988 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 989 { 990 dquot->dq_dqb.dqb_rsvspace += number; 991 } 992 993 /* 994 * Claim reserved quota space 995 */ 996 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 997 { 998 if (dquot->dq_dqb.dqb_rsvspace < number) { 999 WARN_ON_ONCE(1); 1000 number = dquot->dq_dqb.dqb_rsvspace; 1001 } 1002 dquot->dq_dqb.dqb_curspace += number; 1003 dquot->dq_dqb.dqb_rsvspace -= number; 1004 } 1005 1006 static inline 1007 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1008 { 1009 if (dquot->dq_dqb.dqb_rsvspace >= number) 1010 dquot->dq_dqb.dqb_rsvspace -= number; 1011 else { 1012 WARN_ON_ONCE(1); 1013 dquot->dq_dqb.dqb_rsvspace = 0; 1014 } 1015 } 1016 1017 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1018 { 1019 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1020 dquot->dq_dqb.dqb_curinodes >= number) 1021 dquot->dq_dqb.dqb_curinodes -= number; 1022 else 1023 dquot->dq_dqb.dqb_curinodes = 0; 1024 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1025 dquot->dq_dqb.dqb_itime = (time_t) 0; 1026 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1027 } 1028 1029 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1030 { 1031 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1032 dquot->dq_dqb.dqb_curspace >= number) 1033 dquot->dq_dqb.dqb_curspace -= number; 1034 else 1035 dquot->dq_dqb.dqb_curspace = 0; 1036 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1037 dquot->dq_dqb.dqb_btime = (time_t) 0; 1038 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1039 } 1040 1041 static int warning_issued(struct dquot *dquot, const int warntype) 1042 { 1043 int flag = (warntype == QUOTA_NL_BHARDWARN || 1044 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1045 ((warntype == QUOTA_NL_IHARDWARN || 1046 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1047 1048 if (!flag) 1049 return 0; 1050 return test_and_set_bit(flag, &dquot->dq_flags); 1051 } 1052 1053 #ifdef CONFIG_PRINT_QUOTA_WARNING 1054 static int flag_print_warnings = 1; 1055 1056 static int need_print_warning(struct dquot *dquot) 1057 { 1058 if (!flag_print_warnings) 1059 return 0; 1060 1061 switch (dquot->dq_type) { 1062 case USRQUOTA: 1063 return current_fsuid() == dquot->dq_id; 1064 case GRPQUOTA: 1065 return in_group_p(dquot->dq_id); 1066 } 1067 return 0; 1068 } 1069 1070 /* Print warning to user which exceeded quota */ 1071 static void print_warning(struct dquot *dquot, const int warntype) 1072 { 1073 char *msg = NULL; 1074 struct tty_struct *tty; 1075 1076 if (warntype == QUOTA_NL_IHARDBELOW || 1077 warntype == QUOTA_NL_ISOFTBELOW || 1078 warntype == QUOTA_NL_BHARDBELOW || 1079 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1080 return; 1081 1082 tty = get_current_tty(); 1083 if (!tty) 1084 return; 1085 tty_write_message(tty, dquot->dq_sb->s_id); 1086 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1087 tty_write_message(tty, ": warning, "); 1088 else 1089 tty_write_message(tty, ": write failed, "); 1090 tty_write_message(tty, quotatypes[dquot->dq_type]); 1091 switch (warntype) { 1092 case QUOTA_NL_IHARDWARN: 1093 msg = " file limit reached.\r\n"; 1094 break; 1095 case QUOTA_NL_ISOFTLONGWARN: 1096 msg = " file quota exceeded too long.\r\n"; 1097 break; 1098 case QUOTA_NL_ISOFTWARN: 1099 msg = " file quota exceeded.\r\n"; 1100 break; 1101 case QUOTA_NL_BHARDWARN: 1102 msg = " block limit reached.\r\n"; 1103 break; 1104 case QUOTA_NL_BSOFTLONGWARN: 1105 msg = " block quota exceeded too long.\r\n"; 1106 break; 1107 case QUOTA_NL_BSOFTWARN: 1108 msg = " block quota exceeded.\r\n"; 1109 break; 1110 } 1111 tty_write_message(tty, msg); 1112 tty_kref_put(tty); 1113 } 1114 #endif 1115 1116 /* 1117 * Write warnings to the console and send warning messages over netlink. 1118 * 1119 * Note that this function can sleep. 1120 */ 1121 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1122 { 1123 struct dquot *dq; 1124 int i; 1125 1126 for (i = 0; i < MAXQUOTAS; i++) { 1127 dq = dquots[i]; 1128 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1129 !warning_issued(dq, warntype[i])) { 1130 #ifdef CONFIG_PRINT_QUOTA_WARNING 1131 print_warning(dq, warntype[i]); 1132 #endif 1133 quota_send_warning(dq->dq_type, dq->dq_id, 1134 dq->dq_sb->s_dev, warntype[i]); 1135 } 1136 } 1137 } 1138 1139 static int ignore_hardlimit(struct dquot *dquot) 1140 { 1141 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1142 1143 return capable(CAP_SYS_RESOURCE) && 1144 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1145 !(info->dqi_flags & V1_DQF_RSQUASH)); 1146 } 1147 1148 /* needs dq_data_lock */ 1149 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1150 { 1151 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1152 1153 *warntype = QUOTA_NL_NOWARN; 1154 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1155 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1156 return QUOTA_OK; 1157 1158 if (dquot->dq_dqb.dqb_ihardlimit && 1159 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1160 !ignore_hardlimit(dquot)) { 1161 *warntype = QUOTA_NL_IHARDWARN; 1162 return NO_QUOTA; 1163 } 1164 1165 if (dquot->dq_dqb.dqb_isoftlimit && 1166 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1167 dquot->dq_dqb.dqb_itime && 1168 get_seconds() >= dquot->dq_dqb.dqb_itime && 1169 !ignore_hardlimit(dquot)) { 1170 *warntype = QUOTA_NL_ISOFTLONGWARN; 1171 return NO_QUOTA; 1172 } 1173 1174 if (dquot->dq_dqb.dqb_isoftlimit && 1175 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1176 dquot->dq_dqb.dqb_itime == 0) { 1177 *warntype = QUOTA_NL_ISOFTWARN; 1178 dquot->dq_dqb.dqb_itime = get_seconds() + 1179 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1180 } 1181 1182 return QUOTA_OK; 1183 } 1184 1185 /* needs dq_data_lock */ 1186 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1187 { 1188 qsize_t tspace; 1189 struct super_block *sb = dquot->dq_sb; 1190 1191 *warntype = QUOTA_NL_NOWARN; 1192 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1193 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1194 return QUOTA_OK; 1195 1196 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1197 + space; 1198 1199 if (dquot->dq_dqb.dqb_bhardlimit && 1200 tspace > dquot->dq_dqb.dqb_bhardlimit && 1201 !ignore_hardlimit(dquot)) { 1202 if (!prealloc) 1203 *warntype = QUOTA_NL_BHARDWARN; 1204 return NO_QUOTA; 1205 } 1206 1207 if (dquot->dq_dqb.dqb_bsoftlimit && 1208 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1209 dquot->dq_dqb.dqb_btime && 1210 get_seconds() >= dquot->dq_dqb.dqb_btime && 1211 !ignore_hardlimit(dquot)) { 1212 if (!prealloc) 1213 *warntype = QUOTA_NL_BSOFTLONGWARN; 1214 return NO_QUOTA; 1215 } 1216 1217 if (dquot->dq_dqb.dqb_bsoftlimit && 1218 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1219 dquot->dq_dqb.dqb_btime == 0) { 1220 if (!prealloc) { 1221 *warntype = QUOTA_NL_BSOFTWARN; 1222 dquot->dq_dqb.dqb_btime = get_seconds() + 1223 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1224 } 1225 else 1226 /* 1227 * We don't allow preallocation to exceed softlimit so exceeding will 1228 * be always printed 1229 */ 1230 return NO_QUOTA; 1231 } 1232 1233 return QUOTA_OK; 1234 } 1235 1236 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1237 { 1238 qsize_t newinodes; 1239 1240 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1241 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1242 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1243 return QUOTA_NL_NOWARN; 1244 1245 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1246 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1247 return QUOTA_NL_ISOFTBELOW; 1248 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1249 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1250 return QUOTA_NL_IHARDBELOW; 1251 return QUOTA_NL_NOWARN; 1252 } 1253 1254 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1255 { 1256 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1257 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1258 return QUOTA_NL_NOWARN; 1259 1260 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1261 return QUOTA_NL_BSOFTBELOW; 1262 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1263 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1264 return QUOTA_NL_BHARDBELOW; 1265 return QUOTA_NL_NOWARN; 1266 } 1267 1268 /* 1269 * Initialize quota pointers in inode 1270 * We do things in a bit complicated way but by that we avoid calling 1271 * dqget() and thus filesystem callbacks under dqptr_sem. 1272 */ 1273 int dquot_initialize(struct inode *inode, int type) 1274 { 1275 unsigned int id = 0; 1276 int cnt, ret = 0; 1277 struct dquot *got[MAXQUOTAS] = { NULL, NULL }; 1278 struct super_block *sb = inode->i_sb; 1279 qsize_t rsv; 1280 1281 /* First test before acquiring mutex - solves deadlocks when we 1282 * re-enter the quota code and are already holding the mutex */ 1283 if (IS_NOQUOTA(inode)) 1284 return 0; 1285 1286 /* First get references to structures we might need. */ 1287 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1288 if (type != -1 && cnt != type) 1289 continue; 1290 switch (cnt) { 1291 case USRQUOTA: 1292 id = inode->i_uid; 1293 break; 1294 case GRPQUOTA: 1295 id = inode->i_gid; 1296 break; 1297 } 1298 got[cnt] = dqget(sb, id, cnt); 1299 } 1300 1301 down_write(&sb_dqopt(sb)->dqptr_sem); 1302 if (IS_NOQUOTA(inode)) 1303 goto out_err; 1304 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1305 if (type != -1 && cnt != type) 1306 continue; 1307 /* Avoid races with quotaoff() */ 1308 if (!sb_has_quota_active(sb, cnt)) 1309 continue; 1310 if (!inode->i_dquot[cnt]) { 1311 inode->i_dquot[cnt] = got[cnt]; 1312 got[cnt] = NULL; 1313 /* 1314 * Make quota reservation system happy if someone 1315 * did a write before quota was turned on 1316 */ 1317 rsv = inode_get_rsv_space(inode); 1318 if (unlikely(rsv)) 1319 dquot_resv_space(inode->i_dquot[cnt], rsv); 1320 } 1321 } 1322 out_err: 1323 up_write(&sb_dqopt(sb)->dqptr_sem); 1324 /* Drop unused references */ 1325 dqput_all(got); 1326 return ret; 1327 } 1328 EXPORT_SYMBOL(dquot_initialize); 1329 1330 /* 1331 * Release all quotas referenced by inode 1332 */ 1333 int dquot_drop(struct inode *inode) 1334 { 1335 int cnt; 1336 struct dquot *put[MAXQUOTAS]; 1337 1338 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1339 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1340 put[cnt] = inode->i_dquot[cnt]; 1341 inode->i_dquot[cnt] = NULL; 1342 } 1343 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1344 dqput_all(put); 1345 return 0; 1346 } 1347 EXPORT_SYMBOL(dquot_drop); 1348 1349 /* Wrapper to remove references to quota structures from inode */ 1350 void vfs_dq_drop(struct inode *inode) 1351 { 1352 /* Here we can get arbitrary inode from clear_inode() so we have 1353 * to be careful. OTOH we don't need locking as quota operations 1354 * are allowed to change only at mount time */ 1355 if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op 1356 && inode->i_sb->dq_op->drop) { 1357 int cnt; 1358 /* Test before calling to rule out calls from proc and such 1359 * where we are not allowed to block. Note that this is 1360 * actually reliable test even without the lock - the caller 1361 * must assure that nobody can come after the DQUOT_DROP and 1362 * add quota pointers back anyway */ 1363 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1364 if (inode->i_dquot[cnt]) 1365 break; 1366 if (cnt < MAXQUOTAS) 1367 inode->i_sb->dq_op->drop(inode); 1368 } 1369 } 1370 EXPORT_SYMBOL(vfs_dq_drop); 1371 1372 /* 1373 * inode_reserved_space is managed internally by quota, and protected by 1374 * i_lock similar to i_blocks+i_bytes. 1375 */ 1376 static qsize_t *inode_reserved_space(struct inode * inode) 1377 { 1378 /* Filesystem must explicitly define it's own method in order to use 1379 * quota reservation interface */ 1380 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1381 return inode->i_sb->dq_op->get_reserved_space(inode); 1382 } 1383 1384 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1385 { 1386 spin_lock(&inode->i_lock); 1387 *inode_reserved_space(inode) += number; 1388 spin_unlock(&inode->i_lock); 1389 } 1390 EXPORT_SYMBOL(inode_add_rsv_space); 1391 1392 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1393 { 1394 spin_lock(&inode->i_lock); 1395 *inode_reserved_space(inode) -= number; 1396 __inode_add_bytes(inode, number); 1397 spin_unlock(&inode->i_lock); 1398 } 1399 EXPORT_SYMBOL(inode_claim_rsv_space); 1400 1401 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1402 { 1403 spin_lock(&inode->i_lock); 1404 *inode_reserved_space(inode) -= number; 1405 spin_unlock(&inode->i_lock); 1406 } 1407 EXPORT_SYMBOL(inode_sub_rsv_space); 1408 1409 static qsize_t inode_get_rsv_space(struct inode *inode) 1410 { 1411 qsize_t ret; 1412 1413 if (!inode->i_sb->dq_op->get_reserved_space) 1414 return 0; 1415 spin_lock(&inode->i_lock); 1416 ret = *inode_reserved_space(inode); 1417 spin_unlock(&inode->i_lock); 1418 return ret; 1419 } 1420 1421 static void inode_incr_space(struct inode *inode, qsize_t number, 1422 int reserve) 1423 { 1424 if (reserve) 1425 inode_add_rsv_space(inode, number); 1426 else 1427 inode_add_bytes(inode, number); 1428 } 1429 1430 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1431 { 1432 if (reserve) 1433 inode_sub_rsv_space(inode, number); 1434 else 1435 inode_sub_bytes(inode, number); 1436 } 1437 1438 /* 1439 * Following four functions update i_blocks+i_bytes fields and 1440 * quota information (together with appropriate checks) 1441 * NOTE: We absolutely rely on the fact that caller dirties 1442 * the inode (usually macros in quotaops.h care about this) and 1443 * holds a handle for the current transaction so that dquot write and 1444 * inode write go into the same transaction. 1445 */ 1446 1447 /* 1448 * This operation can block, but only after everything is updated 1449 */ 1450 int __dquot_alloc_space(struct inode *inode, qsize_t number, 1451 int warn, int reserve) 1452 { 1453 int cnt, ret = QUOTA_OK; 1454 char warntype[MAXQUOTAS]; 1455 1456 /* 1457 * First test before acquiring mutex - solves deadlocks when we 1458 * re-enter the quota code and are already holding the mutex 1459 */ 1460 if (IS_NOQUOTA(inode)) { 1461 inode_incr_space(inode, number, reserve); 1462 goto out; 1463 } 1464 1465 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1466 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1467 warntype[cnt] = QUOTA_NL_NOWARN; 1468 1469 spin_lock(&dq_data_lock); 1470 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1471 if (!inode->i_dquot[cnt]) 1472 continue; 1473 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) 1474 == NO_QUOTA) { 1475 ret = NO_QUOTA; 1476 spin_unlock(&dq_data_lock); 1477 goto out_flush_warn; 1478 } 1479 } 1480 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1481 if (!inode->i_dquot[cnt]) 1482 continue; 1483 if (reserve) 1484 dquot_resv_space(inode->i_dquot[cnt], number); 1485 else 1486 dquot_incr_space(inode->i_dquot[cnt], number); 1487 } 1488 inode_incr_space(inode, number, reserve); 1489 spin_unlock(&dq_data_lock); 1490 1491 if (reserve) 1492 goto out_flush_warn; 1493 mark_all_dquot_dirty(inode->i_dquot); 1494 out_flush_warn: 1495 flush_warnings(inode->i_dquot, warntype); 1496 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1497 out: 1498 return ret; 1499 } 1500 1501 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn) 1502 { 1503 return __dquot_alloc_space(inode, number, warn, 0); 1504 } 1505 EXPORT_SYMBOL(dquot_alloc_space); 1506 1507 int dquot_reserve_space(struct inode *inode, qsize_t number, int warn) 1508 { 1509 return __dquot_alloc_space(inode, number, warn, 1); 1510 } 1511 EXPORT_SYMBOL(dquot_reserve_space); 1512 1513 /* 1514 * This operation can block, but only after everything is updated 1515 */ 1516 int dquot_alloc_inode(const struct inode *inode, qsize_t number) 1517 { 1518 int cnt, ret = NO_QUOTA; 1519 char warntype[MAXQUOTAS]; 1520 1521 /* First test before acquiring mutex - solves deadlocks when we 1522 * re-enter the quota code and are already holding the mutex */ 1523 if (IS_NOQUOTA(inode)) 1524 return QUOTA_OK; 1525 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1526 warntype[cnt] = QUOTA_NL_NOWARN; 1527 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1528 spin_lock(&dq_data_lock); 1529 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1530 if (!inode->i_dquot[cnt]) 1531 continue; 1532 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) 1533 == NO_QUOTA) 1534 goto warn_put_all; 1535 } 1536 1537 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1538 if (!inode->i_dquot[cnt]) 1539 continue; 1540 dquot_incr_inodes(inode->i_dquot[cnt], number); 1541 } 1542 ret = QUOTA_OK; 1543 warn_put_all: 1544 spin_unlock(&dq_data_lock); 1545 if (ret == QUOTA_OK) 1546 mark_all_dquot_dirty(inode->i_dquot); 1547 flush_warnings(inode->i_dquot, warntype); 1548 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1549 return ret; 1550 } 1551 EXPORT_SYMBOL(dquot_alloc_inode); 1552 1553 int dquot_claim_space(struct inode *inode, qsize_t number) 1554 { 1555 int cnt; 1556 int ret = QUOTA_OK; 1557 1558 if (IS_NOQUOTA(inode)) { 1559 inode_claim_rsv_space(inode, number); 1560 goto out; 1561 } 1562 1563 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1564 spin_lock(&dq_data_lock); 1565 /* Claim reserved quotas to allocated quotas */ 1566 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1567 if (inode->i_dquot[cnt]) 1568 dquot_claim_reserved_space(inode->i_dquot[cnt], 1569 number); 1570 } 1571 /* Update inode bytes */ 1572 inode_claim_rsv_space(inode, number); 1573 spin_unlock(&dq_data_lock); 1574 mark_all_dquot_dirty(inode->i_dquot); 1575 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1576 out: 1577 return ret; 1578 } 1579 EXPORT_SYMBOL(dquot_claim_space); 1580 1581 /* 1582 * This operation can block, but only after everything is updated 1583 */ 1584 int __dquot_free_space(struct inode *inode, qsize_t number, int reserve) 1585 { 1586 unsigned int cnt; 1587 char warntype[MAXQUOTAS]; 1588 1589 /* First test before acquiring mutex - solves deadlocks when we 1590 * re-enter the quota code and are already holding the mutex */ 1591 if (IS_NOQUOTA(inode)) { 1592 inode_decr_space(inode, number, reserve); 1593 return QUOTA_OK; 1594 } 1595 1596 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1597 spin_lock(&dq_data_lock); 1598 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1599 if (!inode->i_dquot[cnt]) 1600 continue; 1601 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1602 if (reserve) 1603 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1604 else 1605 dquot_decr_space(inode->i_dquot[cnt], number); 1606 } 1607 inode_decr_space(inode, number, reserve); 1608 spin_unlock(&dq_data_lock); 1609 1610 if (reserve) 1611 goto out_unlock; 1612 mark_all_dquot_dirty(inode->i_dquot); 1613 out_unlock: 1614 flush_warnings(inode->i_dquot, warntype); 1615 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1616 return QUOTA_OK; 1617 } 1618 1619 int dquot_free_space(struct inode *inode, qsize_t number) 1620 { 1621 return __dquot_free_space(inode, number, 0); 1622 } 1623 EXPORT_SYMBOL(dquot_free_space); 1624 1625 /* 1626 * Release reserved quota space 1627 */ 1628 void dquot_release_reserved_space(struct inode *inode, qsize_t number) 1629 { 1630 __dquot_free_space(inode, number, 1); 1631 1632 } 1633 EXPORT_SYMBOL(dquot_release_reserved_space); 1634 1635 /* 1636 * This operation can block, but only after everything is updated 1637 */ 1638 int dquot_free_inode(const struct inode *inode, qsize_t number) 1639 { 1640 unsigned int cnt; 1641 char warntype[MAXQUOTAS]; 1642 1643 /* First test before acquiring mutex - solves deadlocks when we 1644 * re-enter the quota code and are already holding the mutex */ 1645 if (IS_NOQUOTA(inode)) 1646 return QUOTA_OK; 1647 1648 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1649 spin_lock(&dq_data_lock); 1650 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1651 if (!inode->i_dquot[cnt]) 1652 continue; 1653 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number); 1654 dquot_decr_inodes(inode->i_dquot[cnt], number); 1655 } 1656 spin_unlock(&dq_data_lock); 1657 mark_all_dquot_dirty(inode->i_dquot); 1658 flush_warnings(inode->i_dquot, warntype); 1659 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1660 return QUOTA_OK; 1661 } 1662 EXPORT_SYMBOL(dquot_free_inode); 1663 1664 /* 1665 * Transfer the number of inode and blocks from one diskquota to an other. 1666 * 1667 * This operation can block, but only after everything is updated 1668 * A transaction must be started when entering this function. 1669 */ 1670 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1671 { 1672 qsize_t space, cur_space; 1673 qsize_t rsv_space = 0; 1674 struct dquot *transfer_from[MAXQUOTAS]; 1675 struct dquot *transfer_to[MAXQUOTAS]; 1676 int cnt, ret = QUOTA_OK; 1677 int chuid = iattr->ia_valid & ATTR_UID && inode->i_uid != iattr->ia_uid, 1678 chgid = iattr->ia_valid & ATTR_GID && inode->i_gid != iattr->ia_gid; 1679 char warntype_to[MAXQUOTAS]; 1680 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1681 1682 /* First test before acquiring mutex - solves deadlocks when we 1683 * re-enter the quota code and are already holding the mutex */ 1684 if (IS_NOQUOTA(inode)) 1685 return QUOTA_OK; 1686 /* Initialize the arrays */ 1687 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1688 transfer_from[cnt] = NULL; 1689 transfer_to[cnt] = NULL; 1690 warntype_to[cnt] = QUOTA_NL_NOWARN; 1691 } 1692 if (chuid) 1693 transfer_to[USRQUOTA] = dqget(inode->i_sb, iattr->ia_uid, 1694 USRQUOTA); 1695 if (chgid) 1696 transfer_to[GRPQUOTA] = dqget(inode->i_sb, iattr->ia_gid, 1697 GRPQUOTA); 1698 1699 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1700 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1701 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1702 goto put_all; 1703 } 1704 spin_lock(&dq_data_lock); 1705 cur_space = inode_get_bytes(inode); 1706 rsv_space = inode_get_rsv_space(inode); 1707 space = cur_space + rsv_space; 1708 /* Build the transfer_from list and check the limits */ 1709 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1710 if (!transfer_to[cnt]) 1711 continue; 1712 transfer_from[cnt] = inode->i_dquot[cnt]; 1713 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) == 1714 NO_QUOTA || check_bdq(transfer_to[cnt], space, 0, 1715 warntype_to + cnt) == NO_QUOTA) 1716 goto over_quota; 1717 } 1718 1719 /* 1720 * Finally perform the needed transfer from transfer_from to transfer_to 1721 */ 1722 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1723 /* 1724 * Skip changes for same uid or gid or for turned off quota-type. 1725 */ 1726 if (!transfer_to[cnt]) 1727 continue; 1728 1729 /* Due to IO error we might not have transfer_from[] structure */ 1730 if (transfer_from[cnt]) { 1731 warntype_from_inodes[cnt] = 1732 info_idq_free(transfer_from[cnt], 1); 1733 warntype_from_space[cnt] = 1734 info_bdq_free(transfer_from[cnt], space); 1735 dquot_decr_inodes(transfer_from[cnt], 1); 1736 dquot_decr_space(transfer_from[cnt], cur_space); 1737 dquot_free_reserved_space(transfer_from[cnt], 1738 rsv_space); 1739 } 1740 1741 dquot_incr_inodes(transfer_to[cnt], 1); 1742 dquot_incr_space(transfer_to[cnt], cur_space); 1743 dquot_resv_space(transfer_to[cnt], rsv_space); 1744 1745 inode->i_dquot[cnt] = transfer_to[cnt]; 1746 } 1747 spin_unlock(&dq_data_lock); 1748 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1749 1750 mark_all_dquot_dirty(transfer_from); 1751 mark_all_dquot_dirty(transfer_to); 1752 /* The reference we got is transferred to the inode */ 1753 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1754 transfer_to[cnt] = NULL; 1755 warn_put_all: 1756 flush_warnings(transfer_to, warntype_to); 1757 flush_warnings(transfer_from, warntype_from_inodes); 1758 flush_warnings(transfer_from, warntype_from_space); 1759 put_all: 1760 dqput_all(transfer_from); 1761 dqput_all(transfer_to); 1762 return ret; 1763 over_quota: 1764 spin_unlock(&dq_data_lock); 1765 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1766 /* Clear dquot pointers we don't want to dqput() */ 1767 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1768 transfer_from[cnt] = NULL; 1769 ret = NO_QUOTA; 1770 goto warn_put_all; 1771 } 1772 EXPORT_SYMBOL(dquot_transfer); 1773 1774 /* Wrapper for transferring ownership of an inode */ 1775 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr) 1776 { 1777 if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) { 1778 vfs_dq_init(inode); 1779 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA) 1780 return 1; 1781 } 1782 return 0; 1783 } 1784 EXPORT_SYMBOL(vfs_dq_transfer); 1785 1786 /* 1787 * Write info of quota file to disk 1788 */ 1789 int dquot_commit_info(struct super_block *sb, int type) 1790 { 1791 int ret; 1792 struct quota_info *dqopt = sb_dqopt(sb); 1793 1794 mutex_lock(&dqopt->dqio_mutex); 1795 ret = dqopt->ops[type]->write_file_info(sb, type); 1796 mutex_unlock(&dqopt->dqio_mutex); 1797 return ret; 1798 } 1799 EXPORT_SYMBOL(dquot_commit_info); 1800 1801 /* 1802 * Definitions of diskquota operations. 1803 */ 1804 const struct dquot_operations dquot_operations = { 1805 .initialize = dquot_initialize, 1806 .drop = dquot_drop, 1807 .alloc_space = dquot_alloc_space, 1808 .alloc_inode = dquot_alloc_inode, 1809 .free_space = dquot_free_space, 1810 .free_inode = dquot_free_inode, 1811 .transfer = dquot_transfer, 1812 .write_dquot = dquot_commit, 1813 .acquire_dquot = dquot_acquire, 1814 .release_dquot = dquot_release, 1815 .mark_dirty = dquot_mark_dquot_dirty, 1816 .write_info = dquot_commit_info, 1817 .alloc_dquot = dquot_alloc, 1818 .destroy_dquot = dquot_destroy, 1819 }; 1820 1821 /* 1822 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1823 */ 1824 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags) 1825 { 1826 int cnt, ret = 0; 1827 struct quota_info *dqopt = sb_dqopt(sb); 1828 struct inode *toputinode[MAXQUOTAS]; 1829 1830 /* Cannot turn off usage accounting without turning off limits, or 1831 * suspend quotas and simultaneously turn quotas off. */ 1832 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1833 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1834 DQUOT_USAGE_ENABLED))) 1835 return -EINVAL; 1836 1837 /* We need to serialize quota_off() for device */ 1838 mutex_lock(&dqopt->dqonoff_mutex); 1839 1840 /* 1841 * Skip everything if there's nothing to do. We have to do this because 1842 * sometimes we are called when fill_super() failed and calling 1843 * sync_fs() in such cases does no good. 1844 */ 1845 if (!sb_any_quota_loaded(sb)) { 1846 mutex_unlock(&dqopt->dqonoff_mutex); 1847 return 0; 1848 } 1849 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1850 toputinode[cnt] = NULL; 1851 if (type != -1 && cnt != type) 1852 continue; 1853 if (!sb_has_quota_loaded(sb, cnt)) 1854 continue; 1855 1856 if (flags & DQUOT_SUSPENDED) { 1857 spin_lock(&dq_state_lock); 1858 dqopt->flags |= 1859 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1860 spin_unlock(&dq_state_lock); 1861 } else { 1862 spin_lock(&dq_state_lock); 1863 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1864 /* Turning off suspended quotas? */ 1865 if (!sb_has_quota_loaded(sb, cnt) && 1866 sb_has_quota_suspended(sb, cnt)) { 1867 dqopt->flags &= ~dquot_state_flag( 1868 DQUOT_SUSPENDED, cnt); 1869 spin_unlock(&dq_state_lock); 1870 iput(dqopt->files[cnt]); 1871 dqopt->files[cnt] = NULL; 1872 continue; 1873 } 1874 spin_unlock(&dq_state_lock); 1875 } 1876 1877 /* We still have to keep quota loaded? */ 1878 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1879 continue; 1880 1881 /* Note: these are blocking operations */ 1882 drop_dquot_ref(sb, cnt); 1883 invalidate_dquots(sb, cnt); 1884 /* 1885 * Now all dquots should be invalidated, all writes done so we 1886 * should be only users of the info. No locks needed. 1887 */ 1888 if (info_dirty(&dqopt->info[cnt])) 1889 sb->dq_op->write_info(sb, cnt); 1890 if (dqopt->ops[cnt]->free_file_info) 1891 dqopt->ops[cnt]->free_file_info(sb, cnt); 1892 put_quota_format(dqopt->info[cnt].dqi_format); 1893 1894 toputinode[cnt] = dqopt->files[cnt]; 1895 if (!sb_has_quota_loaded(sb, cnt)) 1896 dqopt->files[cnt] = NULL; 1897 dqopt->info[cnt].dqi_flags = 0; 1898 dqopt->info[cnt].dqi_igrace = 0; 1899 dqopt->info[cnt].dqi_bgrace = 0; 1900 dqopt->ops[cnt] = NULL; 1901 } 1902 mutex_unlock(&dqopt->dqonoff_mutex); 1903 1904 /* Skip syncing and setting flags if quota files are hidden */ 1905 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1906 goto put_inodes; 1907 1908 /* Sync the superblock so that buffers with quota data are written to 1909 * disk (and so userspace sees correct data afterwards). */ 1910 if (sb->s_op->sync_fs) 1911 sb->s_op->sync_fs(sb, 1); 1912 sync_blockdev(sb->s_bdev); 1913 /* Now the quota files are just ordinary files and we can set the 1914 * inode flags back. Moreover we discard the pagecache so that 1915 * userspace sees the writes we did bypassing the pagecache. We 1916 * must also discard the blockdev buffers so that we see the 1917 * changes done by userspace on the next quotaon() */ 1918 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1919 if (toputinode[cnt]) { 1920 mutex_lock(&dqopt->dqonoff_mutex); 1921 /* If quota was reenabled in the meantime, we have 1922 * nothing to do */ 1923 if (!sb_has_quota_loaded(sb, cnt)) { 1924 mutex_lock_nested(&toputinode[cnt]->i_mutex, 1925 I_MUTEX_QUOTA); 1926 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1927 S_NOATIME | S_NOQUOTA); 1928 truncate_inode_pages(&toputinode[cnt]->i_data, 1929 0); 1930 mutex_unlock(&toputinode[cnt]->i_mutex); 1931 mark_inode_dirty(toputinode[cnt]); 1932 } 1933 mutex_unlock(&dqopt->dqonoff_mutex); 1934 } 1935 if (sb->s_bdev) 1936 invalidate_bdev(sb->s_bdev); 1937 put_inodes: 1938 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1939 if (toputinode[cnt]) { 1940 /* On remount RO, we keep the inode pointer so that we 1941 * can reenable quota on the subsequent remount RW. We 1942 * have to check 'flags' variable and not use sb_has_ 1943 * function because another quotaon / quotaoff could 1944 * change global state before we got here. We refuse 1945 * to suspend quotas when there is pending delete on 1946 * the quota file... */ 1947 if (!(flags & DQUOT_SUSPENDED)) 1948 iput(toputinode[cnt]); 1949 else if (!toputinode[cnt]->i_nlink) 1950 ret = -EBUSY; 1951 } 1952 return ret; 1953 } 1954 EXPORT_SYMBOL(vfs_quota_disable); 1955 1956 int vfs_quota_off(struct super_block *sb, int type, int remount) 1957 { 1958 return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED : 1959 (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED)); 1960 } 1961 EXPORT_SYMBOL(vfs_quota_off); 1962 /* 1963 * Turn quotas on on a device 1964 */ 1965 1966 /* 1967 * Helper function to turn quotas on when we already have the inode of 1968 * quota file and no quota information is loaded. 1969 */ 1970 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 1971 unsigned int flags) 1972 { 1973 struct quota_format_type *fmt = find_quota_format(format_id); 1974 struct super_block *sb = inode->i_sb; 1975 struct quota_info *dqopt = sb_dqopt(sb); 1976 int error; 1977 int oldflags = -1; 1978 1979 if (!fmt) 1980 return -ESRCH; 1981 if (!S_ISREG(inode->i_mode)) { 1982 error = -EACCES; 1983 goto out_fmt; 1984 } 1985 if (IS_RDONLY(inode)) { 1986 error = -EROFS; 1987 goto out_fmt; 1988 } 1989 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 1990 error = -EINVAL; 1991 goto out_fmt; 1992 } 1993 /* Usage always has to be set... */ 1994 if (!(flags & DQUOT_USAGE_ENABLED)) { 1995 error = -EINVAL; 1996 goto out_fmt; 1997 } 1998 1999 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2000 /* As we bypass the pagecache we must now flush the inode so 2001 * that we see all the changes from userspace... */ 2002 write_inode_now(inode, 1); 2003 /* And now flush the block cache so that kernel sees the 2004 * changes */ 2005 invalidate_bdev(sb->s_bdev); 2006 } 2007 mutex_lock(&dqopt->dqonoff_mutex); 2008 if (sb_has_quota_loaded(sb, type)) { 2009 error = -EBUSY; 2010 goto out_lock; 2011 } 2012 2013 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2014 /* We don't want quota and atime on quota files (deadlocks 2015 * possible) Also nobody should write to the file - we use 2016 * special IO operations which ignore the immutable bit. */ 2017 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2018 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2019 S_NOQUOTA); 2020 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2021 mutex_unlock(&inode->i_mutex); 2022 /* 2023 * When S_NOQUOTA is set, remove dquot references as no more 2024 * references can be added 2025 */ 2026 sb->dq_op->drop(inode); 2027 } 2028 2029 error = -EIO; 2030 dqopt->files[type] = igrab(inode); 2031 if (!dqopt->files[type]) 2032 goto out_lock; 2033 error = -EINVAL; 2034 if (!fmt->qf_ops->check_quota_file(sb, type)) 2035 goto out_file_init; 2036 2037 dqopt->ops[type] = fmt->qf_ops; 2038 dqopt->info[type].dqi_format = fmt; 2039 dqopt->info[type].dqi_fmt_id = format_id; 2040 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2041 mutex_lock(&dqopt->dqio_mutex); 2042 error = dqopt->ops[type]->read_file_info(sb, type); 2043 if (error < 0) { 2044 mutex_unlock(&dqopt->dqio_mutex); 2045 goto out_file_init; 2046 } 2047 mutex_unlock(&dqopt->dqio_mutex); 2048 spin_lock(&dq_state_lock); 2049 dqopt->flags |= dquot_state_flag(flags, type); 2050 spin_unlock(&dq_state_lock); 2051 2052 add_dquot_ref(sb, type); 2053 mutex_unlock(&dqopt->dqonoff_mutex); 2054 2055 return 0; 2056 2057 out_file_init: 2058 dqopt->files[type] = NULL; 2059 iput(inode); 2060 out_lock: 2061 if (oldflags != -1) { 2062 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2063 /* Set the flags back (in the case of accidental quotaon() 2064 * on a wrong file we don't want to mess up the flags) */ 2065 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2066 inode->i_flags |= oldflags; 2067 mutex_unlock(&inode->i_mutex); 2068 } 2069 mutex_unlock(&dqopt->dqonoff_mutex); 2070 out_fmt: 2071 put_quota_format(fmt); 2072 2073 return error; 2074 } 2075 2076 /* Reenable quotas on remount RW */ 2077 static int vfs_quota_on_remount(struct super_block *sb, int type) 2078 { 2079 struct quota_info *dqopt = sb_dqopt(sb); 2080 struct inode *inode; 2081 int ret; 2082 unsigned int flags; 2083 2084 mutex_lock(&dqopt->dqonoff_mutex); 2085 if (!sb_has_quota_suspended(sb, type)) { 2086 mutex_unlock(&dqopt->dqonoff_mutex); 2087 return 0; 2088 } 2089 inode = dqopt->files[type]; 2090 dqopt->files[type] = NULL; 2091 spin_lock(&dq_state_lock); 2092 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2093 DQUOT_LIMITS_ENABLED, type); 2094 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type); 2095 spin_unlock(&dq_state_lock); 2096 mutex_unlock(&dqopt->dqonoff_mutex); 2097 2098 flags = dquot_generic_flag(flags, type); 2099 ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id, 2100 flags); 2101 iput(inode); 2102 2103 return ret; 2104 } 2105 2106 int vfs_quota_on_path(struct super_block *sb, int type, int format_id, 2107 struct path *path) 2108 { 2109 int error = security_quota_on(path->dentry); 2110 if (error) 2111 return error; 2112 /* Quota file not on the same filesystem? */ 2113 if (path->mnt->mnt_sb != sb) 2114 error = -EXDEV; 2115 else 2116 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2117 format_id, DQUOT_USAGE_ENABLED | 2118 DQUOT_LIMITS_ENABLED); 2119 return error; 2120 } 2121 EXPORT_SYMBOL(vfs_quota_on_path); 2122 2123 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name, 2124 int remount) 2125 { 2126 struct path path; 2127 int error; 2128 2129 if (remount) 2130 return vfs_quota_on_remount(sb, type); 2131 2132 error = kern_path(name, LOOKUP_FOLLOW, &path); 2133 if (!error) { 2134 error = vfs_quota_on_path(sb, type, format_id, &path); 2135 path_put(&path); 2136 } 2137 return error; 2138 } 2139 EXPORT_SYMBOL(vfs_quota_on); 2140 2141 /* 2142 * More powerful function for turning on quotas allowing setting 2143 * of individual quota flags 2144 */ 2145 int vfs_quota_enable(struct inode *inode, int type, int format_id, 2146 unsigned int flags) 2147 { 2148 int ret = 0; 2149 struct super_block *sb = inode->i_sb; 2150 struct quota_info *dqopt = sb_dqopt(sb); 2151 2152 /* Just unsuspend quotas? */ 2153 if (flags & DQUOT_SUSPENDED) 2154 return vfs_quota_on_remount(sb, type); 2155 if (!flags) 2156 return 0; 2157 /* Just updating flags needed? */ 2158 if (sb_has_quota_loaded(sb, type)) { 2159 mutex_lock(&dqopt->dqonoff_mutex); 2160 /* Now do a reliable test... */ 2161 if (!sb_has_quota_loaded(sb, type)) { 2162 mutex_unlock(&dqopt->dqonoff_mutex); 2163 goto load_quota; 2164 } 2165 if (flags & DQUOT_USAGE_ENABLED && 2166 sb_has_quota_usage_enabled(sb, type)) { 2167 ret = -EBUSY; 2168 goto out_lock; 2169 } 2170 if (flags & DQUOT_LIMITS_ENABLED && 2171 sb_has_quota_limits_enabled(sb, type)) { 2172 ret = -EBUSY; 2173 goto out_lock; 2174 } 2175 spin_lock(&dq_state_lock); 2176 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2177 spin_unlock(&dq_state_lock); 2178 out_lock: 2179 mutex_unlock(&dqopt->dqonoff_mutex); 2180 return ret; 2181 } 2182 2183 load_quota: 2184 return vfs_load_quota_inode(inode, type, format_id, flags); 2185 } 2186 EXPORT_SYMBOL(vfs_quota_enable); 2187 2188 /* 2189 * This function is used when filesystem needs to initialize quotas 2190 * during mount time. 2191 */ 2192 int vfs_quota_on_mount(struct super_block *sb, char *qf_name, 2193 int format_id, int type) 2194 { 2195 struct dentry *dentry; 2196 int error; 2197 2198 mutex_lock(&sb->s_root->d_inode->i_mutex); 2199 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2200 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2201 if (IS_ERR(dentry)) 2202 return PTR_ERR(dentry); 2203 2204 if (!dentry->d_inode) { 2205 error = -ENOENT; 2206 goto out; 2207 } 2208 2209 error = security_quota_on(dentry); 2210 if (!error) 2211 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2212 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2213 2214 out: 2215 dput(dentry); 2216 return error; 2217 } 2218 EXPORT_SYMBOL(vfs_quota_on_mount); 2219 2220 /* Wrapper to turn on quotas when remounting rw */ 2221 int vfs_dq_quota_on_remount(struct super_block *sb) 2222 { 2223 int cnt; 2224 int ret = 0, err; 2225 2226 if (!sb->s_qcop || !sb->s_qcop->quota_on) 2227 return -ENOSYS; 2228 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2229 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1); 2230 if (err < 0 && !ret) 2231 ret = err; 2232 } 2233 return ret; 2234 } 2235 EXPORT_SYMBOL(vfs_dq_quota_on_remount); 2236 2237 static inline qsize_t qbtos(qsize_t blocks) 2238 { 2239 return blocks << QIF_DQBLKSIZE_BITS; 2240 } 2241 2242 static inline qsize_t stoqb(qsize_t space) 2243 { 2244 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2245 } 2246 2247 /* Generic routine for getting common part of quota structure */ 2248 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di) 2249 { 2250 struct mem_dqblk *dm = &dquot->dq_dqb; 2251 2252 spin_lock(&dq_data_lock); 2253 di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit); 2254 di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit); 2255 di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace; 2256 di->dqb_ihardlimit = dm->dqb_ihardlimit; 2257 di->dqb_isoftlimit = dm->dqb_isoftlimit; 2258 di->dqb_curinodes = dm->dqb_curinodes; 2259 di->dqb_btime = dm->dqb_btime; 2260 di->dqb_itime = dm->dqb_itime; 2261 di->dqb_valid = QIF_ALL; 2262 spin_unlock(&dq_data_lock); 2263 } 2264 2265 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, 2266 struct if_dqblk *di) 2267 { 2268 struct dquot *dquot; 2269 2270 dquot = dqget(sb, id, type); 2271 if (!dquot) 2272 return -ESRCH; 2273 do_get_dqblk(dquot, di); 2274 dqput(dquot); 2275 2276 return 0; 2277 } 2278 EXPORT_SYMBOL(vfs_get_dqblk); 2279 2280 /* Generic routine for setting common part of quota structure */ 2281 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) 2282 { 2283 struct mem_dqblk *dm = &dquot->dq_dqb; 2284 int check_blim = 0, check_ilim = 0; 2285 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2286 2287 if ((di->dqb_valid & QIF_BLIMITS && 2288 (di->dqb_bhardlimit > dqi->dqi_maxblimit || 2289 di->dqb_bsoftlimit > dqi->dqi_maxblimit)) || 2290 (di->dqb_valid & QIF_ILIMITS && 2291 (di->dqb_ihardlimit > dqi->dqi_maxilimit || 2292 di->dqb_isoftlimit > dqi->dqi_maxilimit))) 2293 return -ERANGE; 2294 2295 spin_lock(&dq_data_lock); 2296 if (di->dqb_valid & QIF_SPACE) { 2297 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace; 2298 check_blim = 1; 2299 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2300 } 2301 if (di->dqb_valid & QIF_BLIMITS) { 2302 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit); 2303 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit); 2304 check_blim = 1; 2305 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2306 } 2307 if (di->dqb_valid & QIF_INODES) { 2308 dm->dqb_curinodes = di->dqb_curinodes; 2309 check_ilim = 1; 2310 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2311 } 2312 if (di->dqb_valid & QIF_ILIMITS) { 2313 dm->dqb_isoftlimit = di->dqb_isoftlimit; 2314 dm->dqb_ihardlimit = di->dqb_ihardlimit; 2315 check_ilim = 1; 2316 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2317 } 2318 if (di->dqb_valid & QIF_BTIME) { 2319 dm->dqb_btime = di->dqb_btime; 2320 check_blim = 1; 2321 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2322 } 2323 if (di->dqb_valid & QIF_ITIME) { 2324 dm->dqb_itime = di->dqb_itime; 2325 check_ilim = 1; 2326 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2327 } 2328 2329 if (check_blim) { 2330 if (!dm->dqb_bsoftlimit || 2331 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2332 dm->dqb_btime = 0; 2333 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2334 } else if (!(di->dqb_valid & QIF_BTIME)) 2335 /* Set grace only if user hasn't provided his own... */ 2336 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2337 } 2338 if (check_ilim) { 2339 if (!dm->dqb_isoftlimit || 2340 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2341 dm->dqb_itime = 0; 2342 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2343 } else if (!(di->dqb_valid & QIF_ITIME)) 2344 /* Set grace only if user hasn't provided his own... */ 2345 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2346 } 2347 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2348 dm->dqb_isoftlimit) 2349 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2350 else 2351 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2352 spin_unlock(&dq_data_lock); 2353 mark_dquot_dirty(dquot); 2354 2355 return 0; 2356 } 2357 2358 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, 2359 struct if_dqblk *di) 2360 { 2361 struct dquot *dquot; 2362 int rc; 2363 2364 dquot = dqget(sb, id, type); 2365 if (!dquot) { 2366 rc = -ESRCH; 2367 goto out; 2368 } 2369 rc = do_set_dqblk(dquot, di); 2370 dqput(dquot); 2371 out: 2372 return rc; 2373 } 2374 EXPORT_SYMBOL(vfs_set_dqblk); 2375 2376 /* Generic routine for getting common part of quota file information */ 2377 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2378 { 2379 struct mem_dqinfo *mi; 2380 2381 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2382 if (!sb_has_quota_active(sb, type)) { 2383 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2384 return -ESRCH; 2385 } 2386 mi = sb_dqopt(sb)->info + type; 2387 spin_lock(&dq_data_lock); 2388 ii->dqi_bgrace = mi->dqi_bgrace; 2389 ii->dqi_igrace = mi->dqi_igrace; 2390 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 2391 ii->dqi_valid = IIF_ALL; 2392 spin_unlock(&dq_data_lock); 2393 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2394 return 0; 2395 } 2396 EXPORT_SYMBOL(vfs_get_dqinfo); 2397 2398 /* Generic routine for setting common part of quota file information */ 2399 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2400 { 2401 struct mem_dqinfo *mi; 2402 int err = 0; 2403 2404 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2405 if (!sb_has_quota_active(sb, type)) { 2406 err = -ESRCH; 2407 goto out; 2408 } 2409 mi = sb_dqopt(sb)->info + type; 2410 spin_lock(&dq_data_lock); 2411 if (ii->dqi_valid & IIF_BGRACE) 2412 mi->dqi_bgrace = ii->dqi_bgrace; 2413 if (ii->dqi_valid & IIF_IGRACE) 2414 mi->dqi_igrace = ii->dqi_igrace; 2415 if (ii->dqi_valid & IIF_FLAGS) 2416 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | 2417 (ii->dqi_flags & DQF_MASK); 2418 spin_unlock(&dq_data_lock); 2419 mark_info_dirty(sb, type); 2420 /* Force write to disk */ 2421 sb->dq_op->write_info(sb, type); 2422 out: 2423 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2424 return err; 2425 } 2426 EXPORT_SYMBOL(vfs_set_dqinfo); 2427 2428 const struct quotactl_ops vfs_quotactl_ops = { 2429 .quota_on = vfs_quota_on, 2430 .quota_off = vfs_quota_off, 2431 .quota_sync = vfs_quota_sync, 2432 .get_info = vfs_get_dqinfo, 2433 .set_info = vfs_set_dqinfo, 2434 .get_dqblk = vfs_get_dqblk, 2435 .set_dqblk = vfs_set_dqblk 2436 }; 2437 2438 static ctl_table fs_dqstats_table[] = { 2439 { 2440 .procname = "lookups", 2441 .data = &dqstats.lookups, 2442 .maxlen = sizeof(int), 2443 .mode = 0444, 2444 .proc_handler = proc_dointvec, 2445 }, 2446 { 2447 .procname = "drops", 2448 .data = &dqstats.drops, 2449 .maxlen = sizeof(int), 2450 .mode = 0444, 2451 .proc_handler = proc_dointvec, 2452 }, 2453 { 2454 .procname = "reads", 2455 .data = &dqstats.reads, 2456 .maxlen = sizeof(int), 2457 .mode = 0444, 2458 .proc_handler = proc_dointvec, 2459 }, 2460 { 2461 .procname = "writes", 2462 .data = &dqstats.writes, 2463 .maxlen = sizeof(int), 2464 .mode = 0444, 2465 .proc_handler = proc_dointvec, 2466 }, 2467 { 2468 .procname = "cache_hits", 2469 .data = &dqstats.cache_hits, 2470 .maxlen = sizeof(int), 2471 .mode = 0444, 2472 .proc_handler = proc_dointvec, 2473 }, 2474 { 2475 .procname = "allocated_dquots", 2476 .data = &dqstats.allocated_dquots, 2477 .maxlen = sizeof(int), 2478 .mode = 0444, 2479 .proc_handler = proc_dointvec, 2480 }, 2481 { 2482 .procname = "free_dquots", 2483 .data = &dqstats.free_dquots, 2484 .maxlen = sizeof(int), 2485 .mode = 0444, 2486 .proc_handler = proc_dointvec, 2487 }, 2488 { 2489 .procname = "syncs", 2490 .data = &dqstats.syncs, 2491 .maxlen = sizeof(int), 2492 .mode = 0444, 2493 .proc_handler = proc_dointvec, 2494 }, 2495 #ifdef CONFIG_PRINT_QUOTA_WARNING 2496 { 2497 .procname = "warnings", 2498 .data = &flag_print_warnings, 2499 .maxlen = sizeof(int), 2500 .mode = 0644, 2501 .proc_handler = proc_dointvec, 2502 }, 2503 #endif 2504 { }, 2505 }; 2506 2507 static ctl_table fs_table[] = { 2508 { 2509 .procname = "quota", 2510 .mode = 0555, 2511 .child = fs_dqstats_table, 2512 }, 2513 { }, 2514 }; 2515 2516 static ctl_table sys_table[] = { 2517 { 2518 .procname = "fs", 2519 .mode = 0555, 2520 .child = fs_table, 2521 }, 2522 { }, 2523 }; 2524 2525 static int __init dquot_init(void) 2526 { 2527 int i; 2528 unsigned long nr_hash, order; 2529 2530 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2531 2532 register_sysctl_table(sys_table); 2533 2534 dquot_cachep = kmem_cache_create("dquot", 2535 sizeof(struct dquot), sizeof(unsigned long) * 4, 2536 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2537 SLAB_MEM_SPREAD|SLAB_PANIC), 2538 NULL); 2539 2540 order = 0; 2541 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2542 if (!dquot_hash) 2543 panic("Cannot create dquot hash table"); 2544 2545 /* Find power-of-two hlist_heads which can fit into allocation */ 2546 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2547 dq_hash_bits = 0; 2548 do { 2549 dq_hash_bits++; 2550 } while (nr_hash >> dq_hash_bits); 2551 dq_hash_bits--; 2552 2553 nr_hash = 1UL << dq_hash_bits; 2554 dq_hash_mask = nr_hash - 1; 2555 for (i = 0; i < nr_hash; i++) 2556 INIT_HLIST_HEAD(dquot_hash + i); 2557 2558 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2559 nr_hash, order, (PAGE_SIZE << order)); 2560 2561 register_shrinker(&dqcache_shrinker); 2562 2563 return 0; 2564 } 2565 module_init(dquot_init); 2566