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, int wait) 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 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)) 619 return 0; 620 621 /* This is not very clever (and fast) but currently I don't know about 622 * any other simple way of getting quota data to disk and we must get 623 * them there for userspace to be visible... */ 624 if (sb->s_op->sync_fs) 625 sb->s_op->sync_fs(sb, 1); 626 sync_blockdev(sb->s_bdev); 627 628 /* 629 * Now when everything is written we can discard the pagecache so 630 * that userspace sees the changes. 631 */ 632 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 633 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 634 if (type != -1 && cnt != type) 635 continue; 636 if (!sb_has_quota_active(sb, cnt)) 637 continue; 638 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, 639 I_MUTEX_QUOTA); 640 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); 641 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); 642 } 643 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 644 645 return 0; 646 } 647 EXPORT_SYMBOL(vfs_quota_sync); 648 649 /* Free unused dquots from cache */ 650 static void prune_dqcache(int count) 651 { 652 struct list_head *head; 653 struct dquot *dquot; 654 655 head = free_dquots.prev; 656 while (head != &free_dquots && count) { 657 dquot = list_entry(head, struct dquot, dq_free); 658 remove_dquot_hash(dquot); 659 remove_free_dquot(dquot); 660 remove_inuse(dquot); 661 do_destroy_dquot(dquot); 662 count--; 663 head = free_dquots.prev; 664 } 665 } 666 667 /* 668 * This is called from kswapd when we think we need some 669 * more memory 670 */ 671 672 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 673 { 674 if (nr) { 675 spin_lock(&dq_list_lock); 676 prune_dqcache(nr); 677 spin_unlock(&dq_list_lock); 678 } 679 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure; 680 } 681 682 static struct shrinker dqcache_shrinker = { 683 .shrink = shrink_dqcache_memory, 684 .seeks = DEFAULT_SEEKS, 685 }; 686 687 /* 688 * Put reference to dquot 689 * NOTE: If you change this function please check whether dqput_blocks() works right... 690 */ 691 void dqput(struct dquot *dquot) 692 { 693 int ret; 694 695 if (!dquot) 696 return; 697 #ifdef __DQUOT_PARANOIA 698 if (!atomic_read(&dquot->dq_count)) { 699 printk("VFS: dqput: trying to free free dquot\n"); 700 printk("VFS: device %s, dquot of %s %d\n", 701 dquot->dq_sb->s_id, 702 quotatypes[dquot->dq_type], 703 dquot->dq_id); 704 BUG(); 705 } 706 #endif 707 708 spin_lock(&dq_list_lock); 709 dqstats.drops++; 710 spin_unlock(&dq_list_lock); 711 we_slept: 712 spin_lock(&dq_list_lock); 713 if (atomic_read(&dquot->dq_count) > 1) { 714 /* We have more than one user... nothing to do */ 715 atomic_dec(&dquot->dq_count); 716 /* Releasing dquot during quotaoff phase? */ 717 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 718 atomic_read(&dquot->dq_count) == 1) 719 wake_up(&dquot->dq_wait_unused); 720 spin_unlock(&dq_list_lock); 721 return; 722 } 723 /* Need to release dquot? */ 724 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 725 spin_unlock(&dq_list_lock); 726 /* Commit dquot before releasing */ 727 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 728 if (ret < 0) { 729 printk(KERN_ERR "VFS: cannot write quota structure on " 730 "device %s (error %d). Quota may get out of " 731 "sync!\n", dquot->dq_sb->s_id, ret); 732 /* 733 * We clear dirty bit anyway, so that we avoid 734 * infinite loop here 735 */ 736 spin_lock(&dq_list_lock); 737 clear_dquot_dirty(dquot); 738 spin_unlock(&dq_list_lock); 739 } 740 goto we_slept; 741 } 742 /* Clear flag in case dquot was inactive (something bad happened) */ 743 clear_dquot_dirty(dquot); 744 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 745 spin_unlock(&dq_list_lock); 746 dquot->dq_sb->dq_op->release_dquot(dquot); 747 goto we_slept; 748 } 749 atomic_dec(&dquot->dq_count); 750 #ifdef __DQUOT_PARANOIA 751 /* sanity check */ 752 BUG_ON(!list_empty(&dquot->dq_free)); 753 #endif 754 put_dquot_last(dquot); 755 spin_unlock(&dq_list_lock); 756 } 757 EXPORT_SYMBOL(dqput); 758 759 struct dquot *dquot_alloc(struct super_block *sb, int type) 760 { 761 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 762 } 763 EXPORT_SYMBOL(dquot_alloc); 764 765 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 766 { 767 struct dquot *dquot; 768 769 dquot = sb->dq_op->alloc_dquot(sb, type); 770 if(!dquot) 771 return NULL; 772 773 mutex_init(&dquot->dq_lock); 774 INIT_LIST_HEAD(&dquot->dq_free); 775 INIT_LIST_HEAD(&dquot->dq_inuse); 776 INIT_HLIST_NODE(&dquot->dq_hash); 777 INIT_LIST_HEAD(&dquot->dq_dirty); 778 init_waitqueue_head(&dquot->dq_wait_unused); 779 dquot->dq_sb = sb; 780 dquot->dq_type = type; 781 atomic_set(&dquot->dq_count, 1); 782 783 return dquot; 784 } 785 786 /* 787 * Get reference to dquot 788 * 789 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 790 * destroying our dquot by: 791 * a) checking for quota flags under dq_list_lock and 792 * b) getting a reference to dquot before we release dq_list_lock 793 */ 794 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 795 { 796 unsigned int hashent = hashfn(sb, id, type); 797 struct dquot *dquot = NULL, *empty = NULL; 798 799 if (!sb_has_quota_active(sb, type)) 800 return NULL; 801 we_slept: 802 spin_lock(&dq_list_lock); 803 spin_lock(&dq_state_lock); 804 if (!sb_has_quota_active(sb, type)) { 805 spin_unlock(&dq_state_lock); 806 spin_unlock(&dq_list_lock); 807 goto out; 808 } 809 spin_unlock(&dq_state_lock); 810 811 dquot = find_dquot(hashent, sb, id, type); 812 if (!dquot) { 813 if (!empty) { 814 spin_unlock(&dq_list_lock); 815 empty = get_empty_dquot(sb, type); 816 if (!empty) 817 schedule(); /* Try to wait for a moment... */ 818 goto we_slept; 819 } 820 dquot = empty; 821 empty = NULL; 822 dquot->dq_id = id; 823 /* all dquots go on the inuse_list */ 824 put_inuse(dquot); 825 /* hash it first so it can be found */ 826 insert_dquot_hash(dquot); 827 dqstats.lookups++; 828 spin_unlock(&dq_list_lock); 829 } else { 830 if (!atomic_read(&dquot->dq_count)) 831 remove_free_dquot(dquot); 832 atomic_inc(&dquot->dq_count); 833 dqstats.cache_hits++; 834 dqstats.lookups++; 835 spin_unlock(&dq_list_lock); 836 } 837 /* Wait for dq_lock - after this we know that either dquot_release() is 838 * already finished or it will be canceled due to dq_count > 1 test */ 839 wait_on_dquot(dquot); 840 /* Read the dquot / allocate space in quota file */ 841 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 842 sb->dq_op->acquire_dquot(dquot) < 0) { 843 dqput(dquot); 844 dquot = NULL; 845 goto out; 846 } 847 #ifdef __DQUOT_PARANOIA 848 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 849 #endif 850 out: 851 if (empty) 852 do_destroy_dquot(empty); 853 854 return dquot; 855 } 856 EXPORT_SYMBOL(dqget); 857 858 static int dqinit_needed(struct inode *inode, int type) 859 { 860 int cnt; 861 862 if (IS_NOQUOTA(inode)) 863 return 0; 864 if (type != -1) 865 return !inode->i_dquot[type]; 866 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 867 if (!inode->i_dquot[cnt]) 868 return 1; 869 return 0; 870 } 871 872 /* This routine is guarded by dqonoff_mutex mutex */ 873 static void add_dquot_ref(struct super_block *sb, int type) 874 { 875 struct inode *inode, *old_inode = NULL; 876 int reserved = 0; 877 878 spin_lock(&inode_lock); 879 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 880 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) 881 continue; 882 if (unlikely(inode_get_rsv_space(inode) > 0)) 883 reserved = 1; 884 if (!atomic_read(&inode->i_writecount)) 885 continue; 886 if (!dqinit_needed(inode, type)) 887 continue; 888 889 __iget(inode); 890 spin_unlock(&inode_lock); 891 892 iput(old_inode); 893 sb->dq_op->initialize(inode, type); 894 /* We hold a reference to 'inode' so it couldn't have been 895 * removed from s_inodes list while we dropped the inode_lock. 896 * We cannot iput the inode now as we can be holding the last 897 * reference and we cannot iput it under inode_lock. So we 898 * keep the reference and iput it later. */ 899 old_inode = inode; 900 spin_lock(&inode_lock); 901 } 902 spin_unlock(&inode_lock); 903 iput(old_inode); 904 905 if (reserved) { 906 printk(KERN_WARNING "VFS (%s): Writes happened before quota" 907 " was turned on thus quota information is probably " 908 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 909 } 910 } 911 912 /* 913 * Return 0 if dqput() won't block. 914 * (note that 1 doesn't necessarily mean blocking) 915 */ 916 static inline int dqput_blocks(struct dquot *dquot) 917 { 918 if (atomic_read(&dquot->dq_count) <= 1) 919 return 1; 920 return 0; 921 } 922 923 /* 924 * Remove references to dquots from inode and add dquot to list for freeing 925 * if we have the last referece to dquot 926 * We can't race with anybody because we hold dqptr_sem for writing... 927 */ 928 static int remove_inode_dquot_ref(struct inode *inode, int type, 929 struct list_head *tofree_head) 930 { 931 struct dquot *dquot = inode->i_dquot[type]; 932 933 inode->i_dquot[type] = NULL; 934 if (dquot) { 935 if (dqput_blocks(dquot)) { 936 #ifdef __DQUOT_PARANOIA 937 if (atomic_read(&dquot->dq_count) != 1) 938 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); 939 #endif 940 spin_lock(&dq_list_lock); 941 /* As dquot must have currently users it can't be on 942 * the free list... */ 943 list_add(&dquot->dq_free, tofree_head); 944 spin_unlock(&dq_list_lock); 945 return 1; 946 } 947 else 948 dqput(dquot); /* We have guaranteed we won't block */ 949 } 950 return 0; 951 } 952 953 /* 954 * Free list of dquots 955 * Dquots are removed from inodes and no new references can be got so we are 956 * the only ones holding reference 957 */ 958 static void put_dquot_list(struct list_head *tofree_head) 959 { 960 struct list_head *act_head; 961 struct dquot *dquot; 962 963 act_head = tofree_head->next; 964 while (act_head != tofree_head) { 965 dquot = list_entry(act_head, struct dquot, dq_free); 966 act_head = act_head->next; 967 /* Remove dquot from the list so we won't have problems... */ 968 list_del_init(&dquot->dq_free); 969 dqput(dquot); 970 } 971 } 972 973 static void remove_dquot_ref(struct super_block *sb, int type, 974 struct list_head *tofree_head) 975 { 976 struct inode *inode; 977 978 spin_lock(&inode_lock); 979 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 980 /* 981 * We have to scan also I_NEW inodes because they can already 982 * have quota pointer initialized. Luckily, we need to touch 983 * only quota pointers and these have separate locking 984 * (dqptr_sem). 985 */ 986 if (!IS_NOQUOTA(inode)) 987 remove_inode_dquot_ref(inode, type, tofree_head); 988 } 989 spin_unlock(&inode_lock); 990 } 991 992 /* Gather all references from inodes and drop them */ 993 static void drop_dquot_ref(struct super_block *sb, int type) 994 { 995 LIST_HEAD(tofree_head); 996 997 if (sb->dq_op) { 998 down_write(&sb_dqopt(sb)->dqptr_sem); 999 remove_dquot_ref(sb, type, &tofree_head); 1000 up_write(&sb_dqopt(sb)->dqptr_sem); 1001 put_dquot_list(&tofree_head); 1002 } 1003 } 1004 1005 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1006 { 1007 dquot->dq_dqb.dqb_curinodes += number; 1008 } 1009 1010 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1011 { 1012 dquot->dq_dqb.dqb_curspace += number; 1013 } 1014 1015 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1016 { 1017 dquot->dq_dqb.dqb_rsvspace += number; 1018 } 1019 1020 /* 1021 * Claim reserved quota space 1022 */ 1023 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1024 { 1025 if (dquot->dq_dqb.dqb_rsvspace < number) { 1026 WARN_ON_ONCE(1); 1027 number = dquot->dq_dqb.dqb_rsvspace; 1028 } 1029 dquot->dq_dqb.dqb_curspace += number; 1030 dquot->dq_dqb.dqb_rsvspace -= number; 1031 } 1032 1033 static inline 1034 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1035 { 1036 if (dquot->dq_dqb.dqb_rsvspace >= number) 1037 dquot->dq_dqb.dqb_rsvspace -= number; 1038 else { 1039 WARN_ON_ONCE(1); 1040 dquot->dq_dqb.dqb_rsvspace = 0; 1041 } 1042 } 1043 1044 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1045 { 1046 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1047 dquot->dq_dqb.dqb_curinodes >= number) 1048 dquot->dq_dqb.dqb_curinodes -= number; 1049 else 1050 dquot->dq_dqb.dqb_curinodes = 0; 1051 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1052 dquot->dq_dqb.dqb_itime = (time_t) 0; 1053 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1054 } 1055 1056 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1057 { 1058 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1059 dquot->dq_dqb.dqb_curspace >= number) 1060 dquot->dq_dqb.dqb_curspace -= number; 1061 else 1062 dquot->dq_dqb.dqb_curspace = 0; 1063 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1064 dquot->dq_dqb.dqb_btime = (time_t) 0; 1065 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1066 } 1067 1068 static int warning_issued(struct dquot *dquot, const int warntype) 1069 { 1070 int flag = (warntype == QUOTA_NL_BHARDWARN || 1071 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1072 ((warntype == QUOTA_NL_IHARDWARN || 1073 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1074 1075 if (!flag) 1076 return 0; 1077 return test_and_set_bit(flag, &dquot->dq_flags); 1078 } 1079 1080 #ifdef CONFIG_PRINT_QUOTA_WARNING 1081 static int flag_print_warnings = 1; 1082 1083 static int need_print_warning(struct dquot *dquot) 1084 { 1085 if (!flag_print_warnings) 1086 return 0; 1087 1088 switch (dquot->dq_type) { 1089 case USRQUOTA: 1090 return current_fsuid() == dquot->dq_id; 1091 case GRPQUOTA: 1092 return in_group_p(dquot->dq_id); 1093 } 1094 return 0; 1095 } 1096 1097 /* Print warning to user which exceeded quota */ 1098 static void print_warning(struct dquot *dquot, const int warntype) 1099 { 1100 char *msg = NULL; 1101 struct tty_struct *tty; 1102 1103 if (warntype == QUOTA_NL_IHARDBELOW || 1104 warntype == QUOTA_NL_ISOFTBELOW || 1105 warntype == QUOTA_NL_BHARDBELOW || 1106 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1107 return; 1108 1109 tty = get_current_tty(); 1110 if (!tty) 1111 return; 1112 tty_write_message(tty, dquot->dq_sb->s_id); 1113 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1114 tty_write_message(tty, ": warning, "); 1115 else 1116 tty_write_message(tty, ": write failed, "); 1117 tty_write_message(tty, quotatypes[dquot->dq_type]); 1118 switch (warntype) { 1119 case QUOTA_NL_IHARDWARN: 1120 msg = " file limit reached.\r\n"; 1121 break; 1122 case QUOTA_NL_ISOFTLONGWARN: 1123 msg = " file quota exceeded too long.\r\n"; 1124 break; 1125 case QUOTA_NL_ISOFTWARN: 1126 msg = " file quota exceeded.\r\n"; 1127 break; 1128 case QUOTA_NL_BHARDWARN: 1129 msg = " block limit reached.\r\n"; 1130 break; 1131 case QUOTA_NL_BSOFTLONGWARN: 1132 msg = " block quota exceeded too long.\r\n"; 1133 break; 1134 case QUOTA_NL_BSOFTWARN: 1135 msg = " block quota exceeded.\r\n"; 1136 break; 1137 } 1138 tty_write_message(tty, msg); 1139 tty_kref_put(tty); 1140 } 1141 #endif 1142 1143 /* 1144 * Write warnings to the console and send warning messages over netlink. 1145 * 1146 * Note that this function can sleep. 1147 */ 1148 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1149 { 1150 struct dquot *dq; 1151 int i; 1152 1153 for (i = 0; i < MAXQUOTAS; i++) { 1154 dq = dquots[i]; 1155 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1156 !warning_issued(dq, warntype[i])) { 1157 #ifdef CONFIG_PRINT_QUOTA_WARNING 1158 print_warning(dq, warntype[i]); 1159 #endif 1160 quota_send_warning(dq->dq_type, dq->dq_id, 1161 dq->dq_sb->s_dev, warntype[i]); 1162 } 1163 } 1164 } 1165 1166 static int ignore_hardlimit(struct dquot *dquot) 1167 { 1168 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1169 1170 return capable(CAP_SYS_RESOURCE) && 1171 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1172 !(info->dqi_flags & V1_DQF_RSQUASH)); 1173 } 1174 1175 /* needs dq_data_lock */ 1176 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1177 { 1178 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1179 1180 *warntype = QUOTA_NL_NOWARN; 1181 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1182 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1183 return QUOTA_OK; 1184 1185 if (dquot->dq_dqb.dqb_ihardlimit && 1186 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1187 !ignore_hardlimit(dquot)) { 1188 *warntype = QUOTA_NL_IHARDWARN; 1189 return NO_QUOTA; 1190 } 1191 1192 if (dquot->dq_dqb.dqb_isoftlimit && 1193 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1194 dquot->dq_dqb.dqb_itime && 1195 get_seconds() >= dquot->dq_dqb.dqb_itime && 1196 !ignore_hardlimit(dquot)) { 1197 *warntype = QUOTA_NL_ISOFTLONGWARN; 1198 return NO_QUOTA; 1199 } 1200 1201 if (dquot->dq_dqb.dqb_isoftlimit && 1202 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1203 dquot->dq_dqb.dqb_itime == 0) { 1204 *warntype = QUOTA_NL_ISOFTWARN; 1205 dquot->dq_dqb.dqb_itime = get_seconds() + 1206 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1207 } 1208 1209 return QUOTA_OK; 1210 } 1211 1212 /* needs dq_data_lock */ 1213 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1214 { 1215 qsize_t tspace; 1216 struct super_block *sb = dquot->dq_sb; 1217 1218 *warntype = QUOTA_NL_NOWARN; 1219 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1220 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1221 return QUOTA_OK; 1222 1223 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1224 + space; 1225 1226 if (dquot->dq_dqb.dqb_bhardlimit && 1227 tspace > dquot->dq_dqb.dqb_bhardlimit && 1228 !ignore_hardlimit(dquot)) { 1229 if (!prealloc) 1230 *warntype = QUOTA_NL_BHARDWARN; 1231 return NO_QUOTA; 1232 } 1233 1234 if (dquot->dq_dqb.dqb_bsoftlimit && 1235 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1236 dquot->dq_dqb.dqb_btime && 1237 get_seconds() >= dquot->dq_dqb.dqb_btime && 1238 !ignore_hardlimit(dquot)) { 1239 if (!prealloc) 1240 *warntype = QUOTA_NL_BSOFTLONGWARN; 1241 return NO_QUOTA; 1242 } 1243 1244 if (dquot->dq_dqb.dqb_bsoftlimit && 1245 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1246 dquot->dq_dqb.dqb_btime == 0) { 1247 if (!prealloc) { 1248 *warntype = QUOTA_NL_BSOFTWARN; 1249 dquot->dq_dqb.dqb_btime = get_seconds() + 1250 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1251 } 1252 else 1253 /* 1254 * We don't allow preallocation to exceed softlimit so exceeding will 1255 * be always printed 1256 */ 1257 return NO_QUOTA; 1258 } 1259 1260 return QUOTA_OK; 1261 } 1262 1263 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1264 { 1265 qsize_t newinodes; 1266 1267 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1268 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1269 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1270 return QUOTA_NL_NOWARN; 1271 1272 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1273 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1274 return QUOTA_NL_ISOFTBELOW; 1275 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1276 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1277 return QUOTA_NL_IHARDBELOW; 1278 return QUOTA_NL_NOWARN; 1279 } 1280 1281 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1282 { 1283 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1284 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1285 return QUOTA_NL_NOWARN; 1286 1287 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1288 return QUOTA_NL_BSOFTBELOW; 1289 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1290 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1291 return QUOTA_NL_BHARDBELOW; 1292 return QUOTA_NL_NOWARN; 1293 } 1294 1295 /* 1296 * Initialize quota pointers in inode 1297 * We do things in a bit complicated way but by that we avoid calling 1298 * dqget() and thus filesystem callbacks under dqptr_sem. 1299 */ 1300 int dquot_initialize(struct inode *inode, int type) 1301 { 1302 unsigned int id = 0; 1303 int cnt, ret = 0; 1304 struct dquot *got[MAXQUOTAS]; 1305 struct super_block *sb = inode->i_sb; 1306 qsize_t rsv; 1307 1308 /* First test before acquiring mutex - solves deadlocks when we 1309 * re-enter the quota code and are already holding the mutex */ 1310 if (IS_NOQUOTA(inode)) 1311 return 0; 1312 1313 /* First get references to structures we might need. */ 1314 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1315 got[cnt] = NULL; 1316 if (type != -1 && cnt != type) 1317 continue; 1318 switch (cnt) { 1319 case USRQUOTA: 1320 id = inode->i_uid; 1321 break; 1322 case GRPQUOTA: 1323 id = inode->i_gid; 1324 break; 1325 } 1326 got[cnt] = dqget(sb, id, cnt); 1327 } 1328 1329 down_write(&sb_dqopt(sb)->dqptr_sem); 1330 if (IS_NOQUOTA(inode)) 1331 goto out_err; 1332 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1333 if (type != -1 && cnt != type) 1334 continue; 1335 /* Avoid races with quotaoff() */ 1336 if (!sb_has_quota_active(sb, cnt)) 1337 continue; 1338 if (!inode->i_dquot[cnt]) { 1339 inode->i_dquot[cnt] = got[cnt]; 1340 got[cnt] = NULL; 1341 /* 1342 * Make quota reservation system happy if someone 1343 * did a write before quota was turned on 1344 */ 1345 rsv = inode_get_rsv_space(inode); 1346 if (unlikely(rsv)) 1347 dquot_resv_space(inode->i_dquot[cnt], rsv); 1348 } 1349 } 1350 out_err: 1351 up_write(&sb_dqopt(sb)->dqptr_sem); 1352 /* Drop unused references */ 1353 dqput_all(got); 1354 return ret; 1355 } 1356 EXPORT_SYMBOL(dquot_initialize); 1357 1358 /* 1359 * Release all quotas referenced by inode 1360 */ 1361 static void __dquot_drop(struct inode *inode) 1362 { 1363 int cnt; 1364 struct dquot *put[MAXQUOTAS]; 1365 1366 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1367 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1368 put[cnt] = inode->i_dquot[cnt]; 1369 inode->i_dquot[cnt] = NULL; 1370 } 1371 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1372 dqput_all(put); 1373 } 1374 1375 void dquot_drop(struct inode *inode) 1376 { 1377 int cnt; 1378 1379 if (IS_NOQUOTA(inode)) 1380 return; 1381 1382 /* 1383 * Test before calling to rule out calls from proc and such 1384 * where we are not allowed to block. Note that this is 1385 * actually reliable test even without the lock - the caller 1386 * must assure that nobody can come after the DQUOT_DROP and 1387 * add quota pointers back anyway. 1388 */ 1389 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1390 if (inode->i_dquot[cnt]) 1391 break; 1392 } 1393 1394 if (cnt < MAXQUOTAS) 1395 __dquot_drop(inode); 1396 } 1397 EXPORT_SYMBOL(dquot_drop); 1398 1399 /* 1400 * inode_reserved_space is managed internally by quota, and protected by 1401 * i_lock similar to i_blocks+i_bytes. 1402 */ 1403 static qsize_t *inode_reserved_space(struct inode * inode) 1404 { 1405 /* Filesystem must explicitly define it's own method in order to use 1406 * quota reservation interface */ 1407 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1408 return inode->i_sb->dq_op->get_reserved_space(inode); 1409 } 1410 1411 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1412 { 1413 spin_lock(&inode->i_lock); 1414 *inode_reserved_space(inode) += number; 1415 spin_unlock(&inode->i_lock); 1416 } 1417 EXPORT_SYMBOL(inode_add_rsv_space); 1418 1419 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1420 { 1421 spin_lock(&inode->i_lock); 1422 *inode_reserved_space(inode) -= number; 1423 __inode_add_bytes(inode, number); 1424 spin_unlock(&inode->i_lock); 1425 } 1426 EXPORT_SYMBOL(inode_claim_rsv_space); 1427 1428 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1429 { 1430 spin_lock(&inode->i_lock); 1431 *inode_reserved_space(inode) -= number; 1432 spin_unlock(&inode->i_lock); 1433 } 1434 EXPORT_SYMBOL(inode_sub_rsv_space); 1435 1436 static qsize_t inode_get_rsv_space(struct inode *inode) 1437 { 1438 qsize_t ret; 1439 1440 if (!inode->i_sb->dq_op->get_reserved_space) 1441 return 0; 1442 spin_lock(&inode->i_lock); 1443 ret = *inode_reserved_space(inode); 1444 spin_unlock(&inode->i_lock); 1445 return ret; 1446 } 1447 1448 static void inode_incr_space(struct inode *inode, qsize_t number, 1449 int reserve) 1450 { 1451 if (reserve) 1452 inode_add_rsv_space(inode, number); 1453 else 1454 inode_add_bytes(inode, number); 1455 } 1456 1457 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1458 { 1459 if (reserve) 1460 inode_sub_rsv_space(inode, number); 1461 else 1462 inode_sub_bytes(inode, number); 1463 } 1464 1465 /* 1466 * This functions updates i_blocks+i_bytes fields and quota information 1467 * (together with appropriate checks). 1468 * 1469 * NOTE: We absolutely rely on the fact that caller dirties the inode 1470 * (usually helpers in quotaops.h care about this) and holds a handle for 1471 * the current transaction so that dquot write and inode write go into the 1472 * same transaction. 1473 */ 1474 1475 /* 1476 * This operation can block, but only after everything is updated 1477 */ 1478 int __dquot_alloc_space(struct inode *inode, qsize_t number, 1479 int warn, int reserve) 1480 { 1481 int cnt, ret = 0; 1482 char warntype[MAXQUOTAS]; 1483 1484 /* 1485 * First test before acquiring mutex - solves deadlocks when we 1486 * re-enter the quota code and are already holding the mutex 1487 */ 1488 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1489 inode_incr_space(inode, number, reserve); 1490 goto out; 1491 } 1492 1493 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1494 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1495 warntype[cnt] = QUOTA_NL_NOWARN; 1496 1497 spin_lock(&dq_data_lock); 1498 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1499 if (!inode->i_dquot[cnt]) 1500 continue; 1501 if (check_bdq(inode->i_dquot[cnt], number, !warn, warntype+cnt) 1502 == NO_QUOTA) { 1503 ret = -EDQUOT; 1504 spin_unlock(&dq_data_lock); 1505 goto out_flush_warn; 1506 } 1507 } 1508 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1509 if (!inode->i_dquot[cnt]) 1510 continue; 1511 if (reserve) 1512 dquot_resv_space(inode->i_dquot[cnt], number); 1513 else 1514 dquot_incr_space(inode->i_dquot[cnt], number); 1515 } 1516 inode_incr_space(inode, number, reserve); 1517 spin_unlock(&dq_data_lock); 1518 1519 if (reserve) 1520 goto out_flush_warn; 1521 mark_all_dquot_dirty(inode->i_dquot); 1522 out_flush_warn: 1523 flush_warnings(inode->i_dquot, warntype); 1524 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1525 out: 1526 return ret; 1527 } 1528 EXPORT_SYMBOL(__dquot_alloc_space); 1529 1530 /* 1531 * This operation can block, but only after everything is updated 1532 */ 1533 int dquot_alloc_inode(const struct inode *inode) 1534 { 1535 int cnt, ret = -EDQUOT; 1536 char warntype[MAXQUOTAS]; 1537 1538 /* First test before acquiring mutex - solves deadlocks when we 1539 * re-enter the quota code and are already holding the mutex */ 1540 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1541 return 0; 1542 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1543 warntype[cnt] = QUOTA_NL_NOWARN; 1544 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1545 spin_lock(&dq_data_lock); 1546 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1547 if (!inode->i_dquot[cnt]) 1548 continue; 1549 if (check_idq(inode->i_dquot[cnt], 1, warntype+cnt) 1550 == NO_QUOTA) 1551 goto warn_put_all; 1552 } 1553 1554 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1555 if (!inode->i_dquot[cnt]) 1556 continue; 1557 dquot_incr_inodes(inode->i_dquot[cnt], 1); 1558 } 1559 ret = 0; 1560 warn_put_all: 1561 spin_unlock(&dq_data_lock); 1562 if (ret == 0) 1563 mark_all_dquot_dirty(inode->i_dquot); 1564 flush_warnings(inode->i_dquot, warntype); 1565 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1566 return ret; 1567 } 1568 EXPORT_SYMBOL(dquot_alloc_inode); 1569 1570 /* 1571 * Convert in-memory reserved quotas to real consumed quotas 1572 */ 1573 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1574 { 1575 int cnt; 1576 1577 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1578 inode_claim_rsv_space(inode, number); 1579 return 0; 1580 } 1581 1582 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1583 spin_lock(&dq_data_lock); 1584 /* Claim reserved quotas to allocated quotas */ 1585 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1586 if (inode->i_dquot[cnt]) 1587 dquot_claim_reserved_space(inode->i_dquot[cnt], 1588 number); 1589 } 1590 /* Update inode bytes */ 1591 inode_claim_rsv_space(inode, number); 1592 spin_unlock(&dq_data_lock); 1593 mark_all_dquot_dirty(inode->i_dquot); 1594 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1595 return 0; 1596 } 1597 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1598 1599 /* 1600 * This operation can block, but only after everything is updated 1601 */ 1602 void __dquot_free_space(struct inode *inode, qsize_t number, int reserve) 1603 { 1604 unsigned int cnt; 1605 char warntype[MAXQUOTAS]; 1606 1607 /* First test before acquiring mutex - solves deadlocks when we 1608 * re-enter the quota code and are already holding the mutex */ 1609 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1610 inode_decr_space(inode, number, reserve); 1611 return; 1612 } 1613 1614 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1615 spin_lock(&dq_data_lock); 1616 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1617 if (!inode->i_dquot[cnt]) 1618 continue; 1619 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1620 if (reserve) 1621 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1622 else 1623 dquot_decr_space(inode->i_dquot[cnt], number); 1624 } 1625 inode_decr_space(inode, number, reserve); 1626 spin_unlock(&dq_data_lock); 1627 1628 if (reserve) 1629 goto out_unlock; 1630 mark_all_dquot_dirty(inode->i_dquot); 1631 out_unlock: 1632 flush_warnings(inode->i_dquot, warntype); 1633 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1634 } 1635 EXPORT_SYMBOL(__dquot_free_space); 1636 1637 /* 1638 * This operation can block, but only after everything is updated 1639 */ 1640 void dquot_free_inode(const struct inode *inode) 1641 { 1642 unsigned int cnt; 1643 char warntype[MAXQUOTAS]; 1644 1645 /* First test before acquiring mutex - solves deadlocks when we 1646 * re-enter the quota code and are already holding the mutex */ 1647 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1648 return; 1649 1650 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1651 spin_lock(&dq_data_lock); 1652 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1653 if (!inode->i_dquot[cnt]) 1654 continue; 1655 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1); 1656 dquot_decr_inodes(inode->i_dquot[cnt], 1); 1657 } 1658 spin_unlock(&dq_data_lock); 1659 mark_all_dquot_dirty(inode->i_dquot); 1660 flush_warnings(inode->i_dquot, warntype); 1661 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1662 } 1663 EXPORT_SYMBOL(dquot_free_inode); 1664 1665 /* 1666 * Transfer the number of inode and blocks from one diskquota to an other. 1667 * 1668 * This operation can block, but only after everything is updated 1669 * A transaction must be started when entering this function. 1670 */ 1671 static int __dquot_transfer(struct inode *inode, qid_t *chid, unsigned long mask) 1672 { 1673 qsize_t space, cur_space; 1674 qsize_t rsv_space = 0; 1675 struct dquot *transfer_from[MAXQUOTAS]; 1676 struct dquot *transfer_to[MAXQUOTAS]; 1677 int cnt, ret = QUOTA_OK; 1678 char warntype_to[MAXQUOTAS]; 1679 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1680 1681 /* First test before acquiring mutex - solves deadlocks when we 1682 * re-enter the quota code and are already holding the mutex */ 1683 if (IS_NOQUOTA(inode)) 1684 return QUOTA_OK; 1685 /* Initialize the arrays */ 1686 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1687 transfer_from[cnt] = NULL; 1688 transfer_to[cnt] = NULL; 1689 warntype_to[cnt] = QUOTA_NL_NOWARN; 1690 } 1691 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1692 if (mask & (1 << cnt)) 1693 transfer_to[cnt] = dqget(inode->i_sb, chid[cnt], cnt); 1694 } 1695 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1696 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1697 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1698 goto put_all; 1699 } 1700 spin_lock(&dq_data_lock); 1701 cur_space = inode_get_bytes(inode); 1702 rsv_space = inode_get_rsv_space(inode); 1703 space = cur_space + rsv_space; 1704 /* Build the transfer_from list and check the limits */ 1705 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1706 if (!transfer_to[cnt]) 1707 continue; 1708 transfer_from[cnt] = inode->i_dquot[cnt]; 1709 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) == 1710 NO_QUOTA || check_bdq(transfer_to[cnt], space, 0, 1711 warntype_to + cnt) == NO_QUOTA) 1712 goto over_quota; 1713 } 1714 1715 /* 1716 * Finally perform the needed transfer from transfer_from to transfer_to 1717 */ 1718 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1719 /* 1720 * Skip changes for same uid or gid or for turned off quota-type. 1721 */ 1722 if (!transfer_to[cnt]) 1723 continue; 1724 1725 /* Due to IO error we might not have transfer_from[] structure */ 1726 if (transfer_from[cnt]) { 1727 warntype_from_inodes[cnt] = 1728 info_idq_free(transfer_from[cnt], 1); 1729 warntype_from_space[cnt] = 1730 info_bdq_free(transfer_from[cnt], space); 1731 dquot_decr_inodes(transfer_from[cnt], 1); 1732 dquot_decr_space(transfer_from[cnt], cur_space); 1733 dquot_free_reserved_space(transfer_from[cnt], 1734 rsv_space); 1735 } 1736 1737 dquot_incr_inodes(transfer_to[cnt], 1); 1738 dquot_incr_space(transfer_to[cnt], cur_space); 1739 dquot_resv_space(transfer_to[cnt], rsv_space); 1740 1741 inode->i_dquot[cnt] = transfer_to[cnt]; 1742 } 1743 spin_unlock(&dq_data_lock); 1744 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1745 1746 mark_all_dquot_dirty(transfer_from); 1747 mark_all_dquot_dirty(transfer_to); 1748 /* The reference we got is transferred to the inode */ 1749 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1750 transfer_to[cnt] = NULL; 1751 warn_put_all: 1752 flush_warnings(transfer_to, warntype_to); 1753 flush_warnings(transfer_from, warntype_from_inodes); 1754 flush_warnings(transfer_from, warntype_from_space); 1755 put_all: 1756 dqput_all(transfer_from); 1757 dqput_all(transfer_to); 1758 return ret; 1759 over_quota: 1760 spin_unlock(&dq_data_lock); 1761 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1762 /* Clear dquot pointers we don't want to dqput() */ 1763 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1764 transfer_from[cnt] = NULL; 1765 ret = NO_QUOTA; 1766 goto warn_put_all; 1767 } 1768 1769 /* Wrapper for transferring ownership of an inode for uid/gid only 1770 * Called from FSXXX_setattr() 1771 */ 1772 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1773 { 1774 qid_t chid[MAXQUOTAS]; 1775 unsigned long mask = 0; 1776 1777 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) { 1778 mask |= 1 << USRQUOTA; 1779 chid[USRQUOTA] = iattr->ia_uid; 1780 } 1781 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) { 1782 mask |= 1 << GRPQUOTA; 1783 chid[GRPQUOTA] = iattr->ia_gid; 1784 } 1785 if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) { 1786 vfs_dq_init(inode); 1787 if (__dquot_transfer(inode, chid, mask) == NO_QUOTA) 1788 return -EDQUOT; 1789 } 1790 return 0; 1791 } 1792 EXPORT_SYMBOL(dquot_transfer); 1793 1794 /* 1795 * Write info of quota file to disk 1796 */ 1797 int dquot_commit_info(struct super_block *sb, int type) 1798 { 1799 int ret; 1800 struct quota_info *dqopt = sb_dqopt(sb); 1801 1802 mutex_lock(&dqopt->dqio_mutex); 1803 ret = dqopt->ops[type]->write_file_info(sb, type); 1804 mutex_unlock(&dqopt->dqio_mutex); 1805 return ret; 1806 } 1807 EXPORT_SYMBOL(dquot_commit_info); 1808 1809 /* 1810 * Definitions of diskquota operations. 1811 */ 1812 const struct dquot_operations dquot_operations = { 1813 .initialize = dquot_initialize, 1814 .write_dquot = dquot_commit, 1815 .acquire_dquot = dquot_acquire, 1816 .release_dquot = dquot_release, 1817 .mark_dirty = dquot_mark_dquot_dirty, 1818 .write_info = dquot_commit_info, 1819 .alloc_dquot = dquot_alloc, 1820 .destroy_dquot = dquot_destroy, 1821 }; 1822 1823 /* 1824 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1825 */ 1826 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags) 1827 { 1828 int cnt, ret = 0; 1829 struct quota_info *dqopt = sb_dqopt(sb); 1830 struct inode *toputinode[MAXQUOTAS]; 1831 1832 /* Cannot turn off usage accounting without turning off limits, or 1833 * suspend quotas and simultaneously turn quotas off. */ 1834 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1835 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1836 DQUOT_USAGE_ENABLED))) 1837 return -EINVAL; 1838 1839 /* We need to serialize quota_off() for device */ 1840 mutex_lock(&dqopt->dqonoff_mutex); 1841 1842 /* 1843 * Skip everything if there's nothing to do. We have to do this because 1844 * sometimes we are called when fill_super() failed and calling 1845 * sync_fs() in such cases does no good. 1846 */ 1847 if (!sb_any_quota_loaded(sb)) { 1848 mutex_unlock(&dqopt->dqonoff_mutex); 1849 return 0; 1850 } 1851 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1852 toputinode[cnt] = NULL; 1853 if (type != -1 && cnt != type) 1854 continue; 1855 if (!sb_has_quota_loaded(sb, cnt)) 1856 continue; 1857 1858 if (flags & DQUOT_SUSPENDED) { 1859 spin_lock(&dq_state_lock); 1860 dqopt->flags |= 1861 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1862 spin_unlock(&dq_state_lock); 1863 } else { 1864 spin_lock(&dq_state_lock); 1865 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1866 /* Turning off suspended quotas? */ 1867 if (!sb_has_quota_loaded(sb, cnt) && 1868 sb_has_quota_suspended(sb, cnt)) { 1869 dqopt->flags &= ~dquot_state_flag( 1870 DQUOT_SUSPENDED, cnt); 1871 spin_unlock(&dq_state_lock); 1872 iput(dqopt->files[cnt]); 1873 dqopt->files[cnt] = NULL; 1874 continue; 1875 } 1876 spin_unlock(&dq_state_lock); 1877 } 1878 1879 /* We still have to keep quota loaded? */ 1880 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1881 continue; 1882 1883 /* Note: these are blocking operations */ 1884 drop_dquot_ref(sb, cnt); 1885 invalidate_dquots(sb, cnt); 1886 /* 1887 * Now all dquots should be invalidated, all writes done so we 1888 * should be only users of the info. No locks needed. 1889 */ 1890 if (info_dirty(&dqopt->info[cnt])) 1891 sb->dq_op->write_info(sb, cnt); 1892 if (dqopt->ops[cnt]->free_file_info) 1893 dqopt->ops[cnt]->free_file_info(sb, cnt); 1894 put_quota_format(dqopt->info[cnt].dqi_format); 1895 1896 toputinode[cnt] = dqopt->files[cnt]; 1897 if (!sb_has_quota_loaded(sb, cnt)) 1898 dqopt->files[cnt] = NULL; 1899 dqopt->info[cnt].dqi_flags = 0; 1900 dqopt->info[cnt].dqi_igrace = 0; 1901 dqopt->info[cnt].dqi_bgrace = 0; 1902 dqopt->ops[cnt] = NULL; 1903 } 1904 mutex_unlock(&dqopt->dqonoff_mutex); 1905 1906 /* Skip syncing and setting flags if quota files are hidden */ 1907 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1908 goto put_inodes; 1909 1910 /* Sync the superblock so that buffers with quota data are written to 1911 * disk (and so userspace sees correct data afterwards). */ 1912 if (sb->s_op->sync_fs) 1913 sb->s_op->sync_fs(sb, 1); 1914 sync_blockdev(sb->s_bdev); 1915 /* Now the quota files are just ordinary files and we can set the 1916 * inode flags back. Moreover we discard the pagecache so that 1917 * userspace sees the writes we did bypassing the pagecache. We 1918 * must also discard the blockdev buffers so that we see the 1919 * changes done by userspace on the next quotaon() */ 1920 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1921 if (toputinode[cnt]) { 1922 mutex_lock(&dqopt->dqonoff_mutex); 1923 /* If quota was reenabled in the meantime, we have 1924 * nothing to do */ 1925 if (!sb_has_quota_loaded(sb, cnt)) { 1926 mutex_lock_nested(&toputinode[cnt]->i_mutex, 1927 I_MUTEX_QUOTA); 1928 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1929 S_NOATIME | S_NOQUOTA); 1930 truncate_inode_pages(&toputinode[cnt]->i_data, 1931 0); 1932 mutex_unlock(&toputinode[cnt]->i_mutex); 1933 mark_inode_dirty(toputinode[cnt]); 1934 } 1935 mutex_unlock(&dqopt->dqonoff_mutex); 1936 } 1937 if (sb->s_bdev) 1938 invalidate_bdev(sb->s_bdev); 1939 put_inodes: 1940 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1941 if (toputinode[cnt]) { 1942 /* On remount RO, we keep the inode pointer so that we 1943 * can reenable quota on the subsequent remount RW. We 1944 * have to check 'flags' variable and not use sb_has_ 1945 * function because another quotaon / quotaoff could 1946 * change global state before we got here. We refuse 1947 * to suspend quotas when there is pending delete on 1948 * the quota file... */ 1949 if (!(flags & DQUOT_SUSPENDED)) 1950 iput(toputinode[cnt]); 1951 else if (!toputinode[cnt]->i_nlink) 1952 ret = -EBUSY; 1953 } 1954 return ret; 1955 } 1956 EXPORT_SYMBOL(vfs_quota_disable); 1957 1958 int vfs_quota_off(struct super_block *sb, int type, int remount) 1959 { 1960 return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED : 1961 (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED)); 1962 } 1963 EXPORT_SYMBOL(vfs_quota_off); 1964 /* 1965 * Turn quotas on on a device 1966 */ 1967 1968 /* 1969 * Helper function to turn quotas on when we already have the inode of 1970 * quota file and no quota information is loaded. 1971 */ 1972 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 1973 unsigned int flags) 1974 { 1975 struct quota_format_type *fmt = find_quota_format(format_id); 1976 struct super_block *sb = inode->i_sb; 1977 struct quota_info *dqopt = sb_dqopt(sb); 1978 int error; 1979 int oldflags = -1; 1980 1981 if (!fmt) 1982 return -ESRCH; 1983 if (!S_ISREG(inode->i_mode)) { 1984 error = -EACCES; 1985 goto out_fmt; 1986 } 1987 if (IS_RDONLY(inode)) { 1988 error = -EROFS; 1989 goto out_fmt; 1990 } 1991 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 1992 error = -EINVAL; 1993 goto out_fmt; 1994 } 1995 /* Usage always has to be set... */ 1996 if (!(flags & DQUOT_USAGE_ENABLED)) { 1997 error = -EINVAL; 1998 goto out_fmt; 1999 } 2000 2001 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2002 /* As we bypass the pagecache we must now flush all the 2003 * dirty data and invalidate caches so that kernel sees 2004 * changes from userspace. It is not enough to just flush 2005 * the quota file since if blocksize < pagesize, invalidation 2006 * of the cache could fail because of other unrelated dirty 2007 * data */ 2008 sync_filesystem(sb); 2009 invalidate_bdev(sb->s_bdev); 2010 } 2011 mutex_lock(&dqopt->dqonoff_mutex); 2012 if (sb_has_quota_loaded(sb, type)) { 2013 error = -EBUSY; 2014 goto out_lock; 2015 } 2016 2017 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2018 /* We don't want quota and atime on quota files (deadlocks 2019 * possible) Also nobody should write to the file - we use 2020 * special IO operations which ignore the immutable bit. */ 2021 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2022 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2023 S_NOQUOTA); 2024 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2025 mutex_unlock(&inode->i_mutex); 2026 /* 2027 * When S_NOQUOTA is set, remove dquot references as no more 2028 * references can be added 2029 */ 2030 __dquot_drop(inode); 2031 } 2032 2033 error = -EIO; 2034 dqopt->files[type] = igrab(inode); 2035 if (!dqopt->files[type]) 2036 goto out_lock; 2037 error = -EINVAL; 2038 if (!fmt->qf_ops->check_quota_file(sb, type)) 2039 goto out_file_init; 2040 2041 dqopt->ops[type] = fmt->qf_ops; 2042 dqopt->info[type].dqi_format = fmt; 2043 dqopt->info[type].dqi_fmt_id = format_id; 2044 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2045 mutex_lock(&dqopt->dqio_mutex); 2046 error = dqopt->ops[type]->read_file_info(sb, type); 2047 if (error < 0) { 2048 mutex_unlock(&dqopt->dqio_mutex); 2049 goto out_file_init; 2050 } 2051 mutex_unlock(&dqopt->dqio_mutex); 2052 spin_lock(&dq_state_lock); 2053 dqopt->flags |= dquot_state_flag(flags, type); 2054 spin_unlock(&dq_state_lock); 2055 2056 add_dquot_ref(sb, type); 2057 mutex_unlock(&dqopt->dqonoff_mutex); 2058 2059 return 0; 2060 2061 out_file_init: 2062 dqopt->files[type] = NULL; 2063 iput(inode); 2064 out_lock: 2065 if (oldflags != -1) { 2066 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2067 /* Set the flags back (in the case of accidental quotaon() 2068 * on a wrong file we don't want to mess up the flags) */ 2069 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2070 inode->i_flags |= oldflags; 2071 mutex_unlock(&inode->i_mutex); 2072 } 2073 mutex_unlock(&dqopt->dqonoff_mutex); 2074 out_fmt: 2075 put_quota_format(fmt); 2076 2077 return error; 2078 } 2079 2080 /* Reenable quotas on remount RW */ 2081 static int vfs_quota_on_remount(struct super_block *sb, int type) 2082 { 2083 struct quota_info *dqopt = sb_dqopt(sb); 2084 struct inode *inode; 2085 int ret; 2086 unsigned int flags; 2087 2088 mutex_lock(&dqopt->dqonoff_mutex); 2089 if (!sb_has_quota_suspended(sb, type)) { 2090 mutex_unlock(&dqopt->dqonoff_mutex); 2091 return 0; 2092 } 2093 inode = dqopt->files[type]; 2094 dqopt->files[type] = NULL; 2095 spin_lock(&dq_state_lock); 2096 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2097 DQUOT_LIMITS_ENABLED, type); 2098 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type); 2099 spin_unlock(&dq_state_lock); 2100 mutex_unlock(&dqopt->dqonoff_mutex); 2101 2102 flags = dquot_generic_flag(flags, type); 2103 ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id, 2104 flags); 2105 iput(inode); 2106 2107 return ret; 2108 } 2109 2110 int vfs_quota_on_path(struct super_block *sb, int type, int format_id, 2111 struct path *path) 2112 { 2113 int error = security_quota_on(path->dentry); 2114 if (error) 2115 return error; 2116 /* Quota file not on the same filesystem? */ 2117 if (path->mnt->mnt_sb != sb) 2118 error = -EXDEV; 2119 else 2120 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2121 format_id, DQUOT_USAGE_ENABLED | 2122 DQUOT_LIMITS_ENABLED); 2123 return error; 2124 } 2125 EXPORT_SYMBOL(vfs_quota_on_path); 2126 2127 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name, 2128 int remount) 2129 { 2130 struct path path; 2131 int error; 2132 2133 if (remount) 2134 return vfs_quota_on_remount(sb, type); 2135 2136 error = kern_path(name, LOOKUP_FOLLOW, &path); 2137 if (!error) { 2138 error = vfs_quota_on_path(sb, type, format_id, &path); 2139 path_put(&path); 2140 } 2141 return error; 2142 } 2143 EXPORT_SYMBOL(vfs_quota_on); 2144 2145 /* 2146 * More powerful function for turning on quotas allowing setting 2147 * of individual quota flags 2148 */ 2149 int vfs_quota_enable(struct inode *inode, int type, int format_id, 2150 unsigned int flags) 2151 { 2152 int ret = 0; 2153 struct super_block *sb = inode->i_sb; 2154 struct quota_info *dqopt = sb_dqopt(sb); 2155 2156 /* Just unsuspend quotas? */ 2157 if (flags & DQUOT_SUSPENDED) 2158 return vfs_quota_on_remount(sb, type); 2159 if (!flags) 2160 return 0; 2161 /* Just updating flags needed? */ 2162 if (sb_has_quota_loaded(sb, type)) { 2163 mutex_lock(&dqopt->dqonoff_mutex); 2164 /* Now do a reliable test... */ 2165 if (!sb_has_quota_loaded(sb, type)) { 2166 mutex_unlock(&dqopt->dqonoff_mutex); 2167 goto load_quota; 2168 } 2169 if (flags & DQUOT_USAGE_ENABLED && 2170 sb_has_quota_usage_enabled(sb, type)) { 2171 ret = -EBUSY; 2172 goto out_lock; 2173 } 2174 if (flags & DQUOT_LIMITS_ENABLED && 2175 sb_has_quota_limits_enabled(sb, type)) { 2176 ret = -EBUSY; 2177 goto out_lock; 2178 } 2179 spin_lock(&dq_state_lock); 2180 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2181 spin_unlock(&dq_state_lock); 2182 out_lock: 2183 mutex_unlock(&dqopt->dqonoff_mutex); 2184 return ret; 2185 } 2186 2187 load_quota: 2188 return vfs_load_quota_inode(inode, type, format_id, flags); 2189 } 2190 EXPORT_SYMBOL(vfs_quota_enable); 2191 2192 /* 2193 * This function is used when filesystem needs to initialize quotas 2194 * during mount time. 2195 */ 2196 int vfs_quota_on_mount(struct super_block *sb, char *qf_name, 2197 int format_id, int type) 2198 { 2199 struct dentry *dentry; 2200 int error; 2201 2202 mutex_lock(&sb->s_root->d_inode->i_mutex); 2203 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2204 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2205 if (IS_ERR(dentry)) 2206 return PTR_ERR(dentry); 2207 2208 if (!dentry->d_inode) { 2209 error = -ENOENT; 2210 goto out; 2211 } 2212 2213 error = security_quota_on(dentry); 2214 if (!error) 2215 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2216 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2217 2218 out: 2219 dput(dentry); 2220 return error; 2221 } 2222 EXPORT_SYMBOL(vfs_quota_on_mount); 2223 2224 /* Wrapper to turn on quotas when remounting rw */ 2225 int vfs_dq_quota_on_remount(struct super_block *sb) 2226 { 2227 int cnt; 2228 int ret = 0, err; 2229 2230 if (!sb->s_qcop || !sb->s_qcop->quota_on) 2231 return -ENOSYS; 2232 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2233 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1); 2234 if (err < 0 && !ret) 2235 ret = err; 2236 } 2237 return ret; 2238 } 2239 EXPORT_SYMBOL(vfs_dq_quota_on_remount); 2240 2241 static inline qsize_t qbtos(qsize_t blocks) 2242 { 2243 return blocks << QIF_DQBLKSIZE_BITS; 2244 } 2245 2246 static inline qsize_t stoqb(qsize_t space) 2247 { 2248 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2249 } 2250 2251 /* Generic routine for getting common part of quota structure */ 2252 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di) 2253 { 2254 struct mem_dqblk *dm = &dquot->dq_dqb; 2255 2256 spin_lock(&dq_data_lock); 2257 di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit); 2258 di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit); 2259 di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace; 2260 di->dqb_ihardlimit = dm->dqb_ihardlimit; 2261 di->dqb_isoftlimit = dm->dqb_isoftlimit; 2262 di->dqb_curinodes = dm->dqb_curinodes; 2263 di->dqb_btime = dm->dqb_btime; 2264 di->dqb_itime = dm->dqb_itime; 2265 di->dqb_valid = QIF_ALL; 2266 spin_unlock(&dq_data_lock); 2267 } 2268 2269 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, 2270 struct if_dqblk *di) 2271 { 2272 struct dquot *dquot; 2273 2274 dquot = dqget(sb, id, type); 2275 if (!dquot) 2276 return -ESRCH; 2277 do_get_dqblk(dquot, di); 2278 dqput(dquot); 2279 2280 return 0; 2281 } 2282 EXPORT_SYMBOL(vfs_get_dqblk); 2283 2284 /* Generic routine for setting common part of quota structure */ 2285 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) 2286 { 2287 struct mem_dqblk *dm = &dquot->dq_dqb; 2288 int check_blim = 0, check_ilim = 0; 2289 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2290 2291 if ((di->dqb_valid & QIF_BLIMITS && 2292 (di->dqb_bhardlimit > dqi->dqi_maxblimit || 2293 di->dqb_bsoftlimit > dqi->dqi_maxblimit)) || 2294 (di->dqb_valid & QIF_ILIMITS && 2295 (di->dqb_ihardlimit > dqi->dqi_maxilimit || 2296 di->dqb_isoftlimit > dqi->dqi_maxilimit))) 2297 return -ERANGE; 2298 2299 spin_lock(&dq_data_lock); 2300 if (di->dqb_valid & QIF_SPACE) { 2301 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace; 2302 check_blim = 1; 2303 __set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2304 } 2305 if (di->dqb_valid & QIF_BLIMITS) { 2306 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit); 2307 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit); 2308 check_blim = 1; 2309 __set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2310 } 2311 if (di->dqb_valid & QIF_INODES) { 2312 dm->dqb_curinodes = di->dqb_curinodes; 2313 check_ilim = 1; 2314 __set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2315 } 2316 if (di->dqb_valid & QIF_ILIMITS) { 2317 dm->dqb_isoftlimit = di->dqb_isoftlimit; 2318 dm->dqb_ihardlimit = di->dqb_ihardlimit; 2319 check_ilim = 1; 2320 __set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2321 } 2322 if (di->dqb_valid & QIF_BTIME) { 2323 dm->dqb_btime = di->dqb_btime; 2324 check_blim = 1; 2325 __set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2326 } 2327 if (di->dqb_valid & QIF_ITIME) { 2328 dm->dqb_itime = di->dqb_itime; 2329 check_ilim = 1; 2330 __set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2331 } 2332 2333 if (check_blim) { 2334 if (!dm->dqb_bsoftlimit || 2335 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2336 dm->dqb_btime = 0; 2337 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2338 } else if (!(di->dqb_valid & QIF_BTIME)) 2339 /* Set grace only if user hasn't provided his own... */ 2340 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2341 } 2342 if (check_ilim) { 2343 if (!dm->dqb_isoftlimit || 2344 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2345 dm->dqb_itime = 0; 2346 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2347 } else if (!(di->dqb_valid & QIF_ITIME)) 2348 /* Set grace only if user hasn't provided his own... */ 2349 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2350 } 2351 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2352 dm->dqb_isoftlimit) 2353 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2354 else 2355 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2356 spin_unlock(&dq_data_lock); 2357 mark_dquot_dirty(dquot); 2358 2359 return 0; 2360 } 2361 2362 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, 2363 struct if_dqblk *di) 2364 { 2365 struct dquot *dquot; 2366 int rc; 2367 2368 dquot = dqget(sb, id, type); 2369 if (!dquot) { 2370 rc = -ESRCH; 2371 goto out; 2372 } 2373 rc = do_set_dqblk(dquot, di); 2374 dqput(dquot); 2375 out: 2376 return rc; 2377 } 2378 EXPORT_SYMBOL(vfs_set_dqblk); 2379 2380 /* Generic routine for getting common part of quota file information */ 2381 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2382 { 2383 struct mem_dqinfo *mi; 2384 2385 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2386 if (!sb_has_quota_active(sb, type)) { 2387 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2388 return -ESRCH; 2389 } 2390 mi = sb_dqopt(sb)->info + type; 2391 spin_lock(&dq_data_lock); 2392 ii->dqi_bgrace = mi->dqi_bgrace; 2393 ii->dqi_igrace = mi->dqi_igrace; 2394 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 2395 ii->dqi_valid = IIF_ALL; 2396 spin_unlock(&dq_data_lock); 2397 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2398 return 0; 2399 } 2400 EXPORT_SYMBOL(vfs_get_dqinfo); 2401 2402 /* Generic routine for setting common part of quota file information */ 2403 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2404 { 2405 struct mem_dqinfo *mi; 2406 int err = 0; 2407 2408 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2409 if (!sb_has_quota_active(sb, type)) { 2410 err = -ESRCH; 2411 goto out; 2412 } 2413 mi = sb_dqopt(sb)->info + type; 2414 spin_lock(&dq_data_lock); 2415 if (ii->dqi_valid & IIF_BGRACE) 2416 mi->dqi_bgrace = ii->dqi_bgrace; 2417 if (ii->dqi_valid & IIF_IGRACE) 2418 mi->dqi_igrace = ii->dqi_igrace; 2419 if (ii->dqi_valid & IIF_FLAGS) 2420 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | 2421 (ii->dqi_flags & DQF_MASK); 2422 spin_unlock(&dq_data_lock); 2423 mark_info_dirty(sb, type); 2424 /* Force write to disk */ 2425 sb->dq_op->write_info(sb, type); 2426 out: 2427 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2428 return err; 2429 } 2430 EXPORT_SYMBOL(vfs_set_dqinfo); 2431 2432 const struct quotactl_ops vfs_quotactl_ops = { 2433 .quota_on = vfs_quota_on, 2434 .quota_off = vfs_quota_off, 2435 .quota_sync = vfs_quota_sync, 2436 .get_info = vfs_get_dqinfo, 2437 .set_info = vfs_set_dqinfo, 2438 .get_dqblk = vfs_get_dqblk, 2439 .set_dqblk = vfs_set_dqblk 2440 }; 2441 2442 static ctl_table fs_dqstats_table[] = { 2443 { 2444 .procname = "lookups", 2445 .data = &dqstats.lookups, 2446 .maxlen = sizeof(int), 2447 .mode = 0444, 2448 .proc_handler = proc_dointvec, 2449 }, 2450 { 2451 .procname = "drops", 2452 .data = &dqstats.drops, 2453 .maxlen = sizeof(int), 2454 .mode = 0444, 2455 .proc_handler = proc_dointvec, 2456 }, 2457 { 2458 .procname = "reads", 2459 .data = &dqstats.reads, 2460 .maxlen = sizeof(int), 2461 .mode = 0444, 2462 .proc_handler = proc_dointvec, 2463 }, 2464 { 2465 .procname = "writes", 2466 .data = &dqstats.writes, 2467 .maxlen = sizeof(int), 2468 .mode = 0444, 2469 .proc_handler = proc_dointvec, 2470 }, 2471 { 2472 .procname = "cache_hits", 2473 .data = &dqstats.cache_hits, 2474 .maxlen = sizeof(int), 2475 .mode = 0444, 2476 .proc_handler = proc_dointvec, 2477 }, 2478 { 2479 .procname = "allocated_dquots", 2480 .data = &dqstats.allocated_dquots, 2481 .maxlen = sizeof(int), 2482 .mode = 0444, 2483 .proc_handler = proc_dointvec, 2484 }, 2485 { 2486 .procname = "free_dquots", 2487 .data = &dqstats.free_dquots, 2488 .maxlen = sizeof(int), 2489 .mode = 0444, 2490 .proc_handler = proc_dointvec, 2491 }, 2492 { 2493 .procname = "syncs", 2494 .data = &dqstats.syncs, 2495 .maxlen = sizeof(int), 2496 .mode = 0444, 2497 .proc_handler = proc_dointvec, 2498 }, 2499 #ifdef CONFIG_PRINT_QUOTA_WARNING 2500 { 2501 .procname = "warnings", 2502 .data = &flag_print_warnings, 2503 .maxlen = sizeof(int), 2504 .mode = 0644, 2505 .proc_handler = proc_dointvec, 2506 }, 2507 #endif 2508 { }, 2509 }; 2510 2511 static ctl_table fs_table[] = { 2512 { 2513 .procname = "quota", 2514 .mode = 0555, 2515 .child = fs_dqstats_table, 2516 }, 2517 { }, 2518 }; 2519 2520 static ctl_table sys_table[] = { 2521 { 2522 .procname = "fs", 2523 .mode = 0555, 2524 .child = fs_table, 2525 }, 2526 { }, 2527 }; 2528 2529 static int __init dquot_init(void) 2530 { 2531 int i; 2532 unsigned long nr_hash, order; 2533 2534 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2535 2536 register_sysctl_table(sys_table); 2537 2538 dquot_cachep = kmem_cache_create("dquot", 2539 sizeof(struct dquot), sizeof(unsigned long) * 4, 2540 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2541 SLAB_MEM_SPREAD|SLAB_PANIC), 2542 NULL); 2543 2544 order = 0; 2545 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2546 if (!dquot_hash) 2547 panic("Cannot create dquot hash table"); 2548 2549 /* Find power-of-two hlist_heads which can fit into allocation */ 2550 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2551 dq_hash_bits = 0; 2552 do { 2553 dq_hash_bits++; 2554 } while (nr_hash >> dq_hash_bits); 2555 dq_hash_bits--; 2556 2557 nr_hash = 1UL << dq_hash_bits; 2558 dq_hash_mask = nr_hash - 1; 2559 for (i = 0; i < nr_hash; i++) 2560 INIT_HLIST_HEAD(dquot_hash + i); 2561 2562 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2563 nr_hash, order, (PAGE_SIZE << order)); 2564 2565 register_shrinker(&dqcache_shrinker); 2566 2567 return 0; 2568 } 2569 module_init(dquot_init); 2570