1 /* 2 * Implementation of the diskquota system for the LINUX operating system. QUOTA 3 * is implemented using the BSD system call interface as the means of 4 * communication with the user level. This file contains the generic routines 5 * called by the different filesystems on allocation of an inode or block. 6 * These routines take care of the administration needed to have a consistent 7 * diskquota tracking system. The ideas of both user and group quotas are based 8 * on the Melbourne quota system as used on BSD derived systems. The internal 9 * implementation is based on one of the several variants of the LINUX 10 * inode-subsystem with added complexity of the diskquota system. 11 * 12 * Author: Marco van Wieringen <mvw@planets.elm.net> 13 * 14 * Fixes: Dmitry Gorodchanin <pgmdsg@ibi.com>, 11 Feb 96 15 * 16 * Revised list management to avoid races 17 * -- Bill Hawes, <whawes@star.net>, 9/98 18 * 19 * Fixed races in dquot_transfer(), dqget() and dquot_alloc_...(). 20 * As the consequence the locking was moved from dquot_decr_...(), 21 * dquot_incr_...() to calling functions. 22 * invalidate_dquots() now writes modified dquots. 23 * Serialized quota_off() and quota_on() for mount point. 24 * Fixed a few bugs in grow_dquots(). 25 * Fixed deadlock in write_dquot() - we no longer account quotas on 26 * quota files 27 * remove_dquot_ref() moved to inode.c - it now traverses through inodes 28 * add_dquot_ref() restarts after blocking 29 * Added check for bogus uid and fixed check for group in quotactl. 30 * Jan Kara, <jack@suse.cz>, sponsored by SuSE CR, 10-11/99 31 * 32 * Used struct list_head instead of own list struct 33 * Invalidation of referenced dquots is no longer possible 34 * Improved free_dquots list management 35 * Quota and i_blocks are now updated in one place to avoid races 36 * Warnings are now delayed so we won't block in critical section 37 * Write updated not to require dquot lock 38 * Jan Kara, <jack@suse.cz>, 9/2000 39 * 40 * Added dynamic quota structure allocation 41 * Jan Kara <jack@suse.cz> 12/2000 42 * 43 * Rewritten quota interface. Implemented new quota format and 44 * formats registering. 45 * Jan Kara, <jack@suse.cz>, 2001,2002 46 * 47 * New SMP locking. 48 * Jan Kara, <jack@suse.cz>, 10/2002 49 * 50 * Added journalled quota support, fix lock inversion problems 51 * Jan Kara, <jack@suse.cz>, 2003,2004 52 * 53 * (C) Copyright 1994 - 1997 Marco van Wieringen 54 */ 55 56 #include <linux/errno.h> 57 #include <linux/kernel.h> 58 #include <linux/fs.h> 59 #include <linux/mount.h> 60 #include <linux/mm.h> 61 #include <linux/time.h> 62 #include <linux/types.h> 63 #include <linux/string.h> 64 #include <linux/fcntl.h> 65 #include <linux/stat.h> 66 #include <linux/tty.h> 67 #include <linux/file.h> 68 #include <linux/slab.h> 69 #include <linux/sysctl.h> 70 #include <linux/init.h> 71 #include <linux/module.h> 72 #include <linux/proc_fs.h> 73 #include <linux/security.h> 74 #include <linux/kmod.h> 75 #include <linux/namei.h> 76 #include <linux/buffer_head.h> 77 #include <linux/capability.h> 78 #include <linux/quotaops.h> 79 #include <linux/writeback.h> /* for inode_lock, oddly enough.. */ 80 81 #include <asm/uaccess.h> 82 83 /* 84 * There are three quota SMP locks. dq_list_lock protects all lists with quotas 85 * and quota formats, dqstats structure containing statistics about the lists 86 * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and 87 * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes. 88 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly 89 * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects 90 * modifications of quota state (on quotaon and quotaoff) and readers who care 91 * about latest values take it as well. 92 * 93 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock, 94 * dq_list_lock > dq_state_lock 95 * 96 * Note that some things (eg. sb pointer, type, id) doesn't change during 97 * the life of the dquot structure and so needn't to be protected by a lock 98 * 99 * Any operation working on dquots via inode pointers must hold dqptr_sem. If 100 * operation is just reading pointers from inode (or not using them at all) the 101 * read lock is enough. If pointers are altered function must hold write lock. 102 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 103 * inode is a quota file). Functions adding pointers from inode to dquots have 104 * to check this flag under dqptr_sem and then (if S_NOQUOTA is not set) they 105 * have to do all pointer modifications before dropping dqptr_sem. This makes 106 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 107 * then drops all pointers to dquots from an inode. 108 * 109 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced 110 * from inodes (dquot_alloc_space() and such don't check the dq_lock). 111 * Currently dquot is locked only when it is being read to memory (or space for 112 * it is being allocated) on the first dqget() and when it is being released on 113 * the last dqput(). The allocation and release oparations are serialized by 114 * the dq_lock and by checking the use count in dquot_release(). Write 115 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock 116 * spinlock to internal buffers before writing. 117 * 118 * Lock ordering (including related VFS locks) is the following: 119 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > 120 * dqio_mutex 121 * The lock ordering of dqptr_sem imposed by quota code is only dqonoff_sem > 122 * dqptr_sem. But filesystem has to count with the fact that functions such as 123 * dquot_alloc_space() acquire dqptr_sem and they usually have to be called 124 * from inside a transaction to keep filesystem consistency after a crash. Also 125 * filesystems usually want to do some IO on dquot from ->mark_dirty which is 126 * called with dqptr_sem held. 127 * i_mutex on quota files is special (it's below dqio_mutex) 128 */ 129 130 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 131 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 132 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 133 EXPORT_SYMBOL(dq_data_lock); 134 135 static char *quotatypes[] = INITQFNAMES; 136 static struct quota_format_type *quota_formats; /* List of registered formats */ 137 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 138 139 /* SLAB cache for dquot structures */ 140 static struct kmem_cache *dquot_cachep; 141 142 int register_quota_format(struct quota_format_type *fmt) 143 { 144 spin_lock(&dq_list_lock); 145 fmt->qf_next = quota_formats; 146 quota_formats = fmt; 147 spin_unlock(&dq_list_lock); 148 return 0; 149 } 150 EXPORT_SYMBOL(register_quota_format); 151 152 void unregister_quota_format(struct quota_format_type *fmt) 153 { 154 struct quota_format_type **actqf; 155 156 spin_lock(&dq_list_lock); 157 for (actqf = "a_formats; *actqf && *actqf != fmt; 158 actqf = &(*actqf)->qf_next) 159 ; 160 if (*actqf) 161 *actqf = (*actqf)->qf_next; 162 spin_unlock(&dq_list_lock); 163 } 164 EXPORT_SYMBOL(unregister_quota_format); 165 166 static struct quota_format_type *find_quota_format(int id) 167 { 168 struct quota_format_type *actqf; 169 170 spin_lock(&dq_list_lock); 171 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 172 actqf = actqf->qf_next) 173 ; 174 if (!actqf || !try_module_get(actqf->qf_owner)) { 175 int qm; 176 177 spin_unlock(&dq_list_lock); 178 179 for (qm = 0; module_names[qm].qm_fmt_id && 180 module_names[qm].qm_fmt_id != id; qm++) 181 ; 182 if (!module_names[qm].qm_fmt_id || 183 request_module(module_names[qm].qm_mod_name)) 184 return NULL; 185 186 spin_lock(&dq_list_lock); 187 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 188 actqf = actqf->qf_next) 189 ; 190 if (actqf && !try_module_get(actqf->qf_owner)) 191 actqf = NULL; 192 } 193 spin_unlock(&dq_list_lock); 194 return actqf; 195 } 196 197 static void put_quota_format(struct quota_format_type *fmt) 198 { 199 module_put(fmt->qf_owner); 200 } 201 202 /* 203 * Dquot List Management: 204 * The quota code uses three lists for dquot management: the inuse_list, 205 * free_dquots, and dquot_hash[] array. A single dquot structure may be 206 * on all three lists, depending on its current state. 207 * 208 * All dquots are placed to the end of inuse_list when first created, and this 209 * list is used for invalidate operation, which must look at every dquot. 210 * 211 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 212 * and this list is searched whenever we need an available dquot. Dquots are 213 * removed from the list as soon as they are used again, and 214 * dqstats.free_dquots gives the number of dquots on the list. When 215 * dquot is invalidated it's completely released from memory. 216 * 217 * Dquots with a specific identity (device, type and id) are placed on 218 * one of the dquot_hash[] hash chains. The provides an efficient search 219 * mechanism to locate a specific dquot. 220 */ 221 222 static LIST_HEAD(inuse_list); 223 static LIST_HEAD(free_dquots); 224 static unsigned int dq_hash_bits, dq_hash_mask; 225 static struct hlist_head *dquot_hash; 226 227 struct dqstats dqstats; 228 EXPORT_SYMBOL(dqstats); 229 230 static qsize_t inode_get_rsv_space(struct inode *inode); 231 static void __dquot_initialize(struct inode *inode, int type); 232 233 static inline unsigned int 234 hashfn(const struct super_block *sb, unsigned int id, int type) 235 { 236 unsigned long tmp; 237 238 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 239 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 240 } 241 242 /* 243 * Following list functions expect dq_list_lock to be held 244 */ 245 static inline void insert_dquot_hash(struct dquot *dquot) 246 { 247 struct hlist_head *head; 248 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 249 hlist_add_head(&dquot->dq_hash, head); 250 } 251 252 static inline void remove_dquot_hash(struct dquot *dquot) 253 { 254 hlist_del_init(&dquot->dq_hash); 255 } 256 257 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 258 unsigned int id, int type) 259 { 260 struct hlist_node *node; 261 struct dquot *dquot; 262 263 hlist_for_each (node, dquot_hash+hashent) { 264 dquot = hlist_entry(node, struct dquot, dq_hash); 265 if (dquot->dq_sb == sb && dquot->dq_id == id && 266 dquot->dq_type == type) 267 return dquot; 268 } 269 return NULL; 270 } 271 272 /* Add a dquot to the tail of the free list */ 273 static inline void put_dquot_last(struct dquot *dquot) 274 { 275 list_add_tail(&dquot->dq_free, &free_dquots); 276 dqstats.free_dquots++; 277 } 278 279 static inline void remove_free_dquot(struct dquot *dquot) 280 { 281 if (list_empty(&dquot->dq_free)) 282 return; 283 list_del_init(&dquot->dq_free); 284 dqstats.free_dquots--; 285 } 286 287 static inline void put_inuse(struct dquot *dquot) 288 { 289 /* We add to the back of inuse list so we don't have to restart 290 * when traversing this list and we block */ 291 list_add_tail(&dquot->dq_inuse, &inuse_list); 292 dqstats.allocated_dquots++; 293 } 294 295 static inline void remove_inuse(struct dquot *dquot) 296 { 297 dqstats.allocated_dquots--; 298 list_del(&dquot->dq_inuse); 299 } 300 /* 301 * End of list functions needing dq_list_lock 302 */ 303 304 static void wait_on_dquot(struct dquot *dquot) 305 { 306 mutex_lock(&dquot->dq_lock); 307 mutex_unlock(&dquot->dq_lock); 308 } 309 310 static inline int dquot_dirty(struct dquot *dquot) 311 { 312 return test_bit(DQ_MOD_B, &dquot->dq_flags); 313 } 314 315 static inline int mark_dquot_dirty(struct dquot *dquot) 316 { 317 return dquot->dq_sb->dq_op->mark_dirty(dquot); 318 } 319 320 int dquot_mark_dquot_dirty(struct dquot *dquot) 321 { 322 spin_lock(&dq_list_lock); 323 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) 324 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 325 info[dquot->dq_type].dqi_dirty_list); 326 spin_unlock(&dq_list_lock); 327 return 0; 328 } 329 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 330 331 /* Dirtify all the dquots - this can block when journalling */ 332 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 333 { 334 int ret, err, cnt; 335 336 ret = err = 0; 337 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 338 if (dquot[cnt]) 339 /* Even in case of error we have to continue */ 340 ret = mark_dquot_dirty(dquot[cnt]); 341 if (!err) 342 err = ret; 343 } 344 return err; 345 } 346 347 static inline void dqput_all(struct dquot **dquot) 348 { 349 unsigned int cnt; 350 351 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 352 dqput(dquot[cnt]); 353 } 354 355 /* This function needs dq_list_lock */ 356 static inline int clear_dquot_dirty(struct dquot *dquot) 357 { 358 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 359 return 0; 360 list_del_init(&dquot->dq_dirty); 361 return 1; 362 } 363 364 void mark_info_dirty(struct super_block *sb, int type) 365 { 366 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 367 } 368 EXPORT_SYMBOL(mark_info_dirty); 369 370 /* 371 * Read dquot from disk and alloc space for it 372 */ 373 374 int dquot_acquire(struct dquot *dquot) 375 { 376 int ret = 0, ret2 = 0; 377 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 378 379 mutex_lock(&dquot->dq_lock); 380 mutex_lock(&dqopt->dqio_mutex); 381 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 382 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 383 if (ret < 0) 384 goto out_iolock; 385 set_bit(DQ_READ_B, &dquot->dq_flags); 386 /* Instantiate dquot if needed */ 387 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 388 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 389 /* Write the info if needed */ 390 if (info_dirty(&dqopt->info[dquot->dq_type])) { 391 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 392 dquot->dq_sb, dquot->dq_type); 393 } 394 if (ret < 0) 395 goto out_iolock; 396 if (ret2 < 0) { 397 ret = ret2; 398 goto out_iolock; 399 } 400 } 401 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 402 out_iolock: 403 mutex_unlock(&dqopt->dqio_mutex); 404 mutex_unlock(&dquot->dq_lock); 405 return ret; 406 } 407 EXPORT_SYMBOL(dquot_acquire); 408 409 /* 410 * Write dquot to disk 411 */ 412 int dquot_commit(struct dquot *dquot) 413 { 414 int ret = 0, ret2 = 0; 415 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 416 417 mutex_lock(&dqopt->dqio_mutex); 418 spin_lock(&dq_list_lock); 419 if (!clear_dquot_dirty(dquot)) { 420 spin_unlock(&dq_list_lock); 421 goto out_sem; 422 } 423 spin_unlock(&dq_list_lock); 424 /* Inactive dquot can be only if there was error during read/init 425 * => we have better not writing it */ 426 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 427 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 428 if (info_dirty(&dqopt->info[dquot->dq_type])) { 429 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 430 dquot->dq_sb, dquot->dq_type); 431 } 432 if (ret >= 0) 433 ret = ret2; 434 } 435 out_sem: 436 mutex_unlock(&dqopt->dqio_mutex); 437 return ret; 438 } 439 EXPORT_SYMBOL(dquot_commit); 440 441 /* 442 * Release dquot 443 */ 444 int dquot_release(struct dquot *dquot) 445 { 446 int ret = 0, ret2 = 0; 447 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 448 449 mutex_lock(&dquot->dq_lock); 450 /* Check whether we are not racing with some other dqget() */ 451 if (atomic_read(&dquot->dq_count) > 1) 452 goto out_dqlock; 453 mutex_lock(&dqopt->dqio_mutex); 454 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 455 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 456 /* Write the info */ 457 if (info_dirty(&dqopt->info[dquot->dq_type])) { 458 ret2 = dqopt->ops[dquot->dq_type]->write_file_info( 459 dquot->dq_sb, dquot->dq_type); 460 } 461 if (ret >= 0) 462 ret = ret2; 463 } 464 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 465 mutex_unlock(&dqopt->dqio_mutex); 466 out_dqlock: 467 mutex_unlock(&dquot->dq_lock); 468 return ret; 469 } 470 EXPORT_SYMBOL(dquot_release); 471 472 void dquot_destroy(struct dquot *dquot) 473 { 474 kmem_cache_free(dquot_cachep, dquot); 475 } 476 EXPORT_SYMBOL(dquot_destroy); 477 478 static inline void do_destroy_dquot(struct dquot *dquot) 479 { 480 dquot->dq_sb->dq_op->destroy_dquot(dquot); 481 } 482 483 /* Invalidate all dquots on the list. Note that this function is called after 484 * quota is disabled and pointers from inodes removed so there cannot be new 485 * quota users. There can still be some users of quotas due to inodes being 486 * just deleted or pruned by prune_icache() (those are not attached to any 487 * list) or parallel quotactl call. We have to wait for such users. 488 */ 489 static void invalidate_dquots(struct super_block *sb, int type) 490 { 491 struct dquot *dquot, *tmp; 492 493 restart: 494 spin_lock(&dq_list_lock); 495 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 496 if (dquot->dq_sb != sb) 497 continue; 498 if (dquot->dq_type != type) 499 continue; 500 /* Wait for dquot users */ 501 if (atomic_read(&dquot->dq_count)) { 502 DEFINE_WAIT(wait); 503 504 atomic_inc(&dquot->dq_count); 505 prepare_to_wait(&dquot->dq_wait_unused, &wait, 506 TASK_UNINTERRUPTIBLE); 507 spin_unlock(&dq_list_lock); 508 /* Once dqput() wakes us up, we know it's time to free 509 * the dquot. 510 * IMPORTANT: we rely on the fact that there is always 511 * at most one process waiting for dquot to free. 512 * Otherwise dq_count would be > 1 and we would never 513 * wake up. 514 */ 515 if (atomic_read(&dquot->dq_count) > 1) 516 schedule(); 517 finish_wait(&dquot->dq_wait_unused, &wait); 518 dqput(dquot); 519 /* At this moment dquot() need not exist (it could be 520 * reclaimed by prune_dqcache(). Hence we must 521 * restart. */ 522 goto restart; 523 } 524 /* 525 * Quota now has no users and it has been written on last 526 * dqput() 527 */ 528 remove_dquot_hash(dquot); 529 remove_free_dquot(dquot); 530 remove_inuse(dquot); 531 do_destroy_dquot(dquot); 532 } 533 spin_unlock(&dq_list_lock); 534 } 535 536 /* Call callback for every active dquot on given filesystem */ 537 int dquot_scan_active(struct super_block *sb, 538 int (*fn)(struct dquot *dquot, unsigned long priv), 539 unsigned long priv) 540 { 541 struct dquot *dquot, *old_dquot = NULL; 542 int ret = 0; 543 544 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 545 spin_lock(&dq_list_lock); 546 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 547 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 548 continue; 549 if (dquot->dq_sb != sb) 550 continue; 551 /* Now we have active dquot so we can just increase use count */ 552 atomic_inc(&dquot->dq_count); 553 dqstats.lookups++; 554 spin_unlock(&dq_list_lock); 555 dqput(old_dquot); 556 old_dquot = dquot; 557 ret = fn(dquot, priv); 558 if (ret < 0) 559 goto out; 560 spin_lock(&dq_list_lock); 561 /* We are safe to continue now because our dquot could not 562 * be moved out of the inuse list while we hold the reference */ 563 } 564 spin_unlock(&dq_list_lock); 565 out: 566 dqput(old_dquot); 567 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 568 return ret; 569 } 570 EXPORT_SYMBOL(dquot_scan_active); 571 572 int vfs_quota_sync(struct super_block *sb, int type, int wait) 573 { 574 struct list_head *dirty; 575 struct dquot *dquot; 576 struct quota_info *dqopt = sb_dqopt(sb); 577 int cnt; 578 579 mutex_lock(&dqopt->dqonoff_mutex); 580 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 581 if (type != -1 && cnt != type) 582 continue; 583 if (!sb_has_quota_active(sb, cnt)) 584 continue; 585 spin_lock(&dq_list_lock); 586 dirty = &dqopt->info[cnt].dqi_dirty_list; 587 while (!list_empty(dirty)) { 588 dquot = list_first_entry(dirty, struct dquot, 589 dq_dirty); 590 /* Dirty and inactive can be only bad dquot... */ 591 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 592 clear_dquot_dirty(dquot); 593 continue; 594 } 595 /* Now we have active dquot from which someone is 596 * holding reference so we can safely just increase 597 * use count */ 598 atomic_inc(&dquot->dq_count); 599 dqstats.lookups++; 600 spin_unlock(&dq_list_lock); 601 sb->dq_op->write_dquot(dquot); 602 dqput(dquot); 603 spin_lock(&dq_list_lock); 604 } 605 spin_unlock(&dq_list_lock); 606 } 607 608 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 609 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 610 && info_dirty(&dqopt->info[cnt])) 611 sb->dq_op->write_info(sb, cnt); 612 spin_lock(&dq_list_lock); 613 dqstats.syncs++; 614 spin_unlock(&dq_list_lock); 615 mutex_unlock(&dqopt->dqonoff_mutex); 616 617 if (!wait || (sb_dqopt(sb)->flags & DQUOT_QUOTA_SYS_FILE)) 618 return 0; 619 620 /* This is not very clever (and fast) but currently I don't know about 621 * any other simple way of getting quota data to disk and we must get 622 * them there for userspace to be visible... */ 623 if (sb->s_op->sync_fs) 624 sb->s_op->sync_fs(sb, 1); 625 sync_blockdev(sb->s_bdev); 626 627 /* 628 * Now when everything is written we can discard the pagecache so 629 * that userspace sees the changes. 630 */ 631 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 632 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 633 if (type != -1 && cnt != type) 634 continue; 635 if (!sb_has_quota_active(sb, cnt)) 636 continue; 637 mutex_lock_nested(&sb_dqopt(sb)->files[cnt]->i_mutex, 638 I_MUTEX_QUOTA); 639 truncate_inode_pages(&sb_dqopt(sb)->files[cnt]->i_data, 0); 640 mutex_unlock(&sb_dqopt(sb)->files[cnt]->i_mutex); 641 } 642 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 643 644 return 0; 645 } 646 EXPORT_SYMBOL(vfs_quota_sync); 647 648 /* Free unused dquots from cache */ 649 static void prune_dqcache(int count) 650 { 651 struct list_head *head; 652 struct dquot *dquot; 653 654 head = free_dquots.prev; 655 while (head != &free_dquots && count) { 656 dquot = list_entry(head, struct dquot, dq_free); 657 remove_dquot_hash(dquot); 658 remove_free_dquot(dquot); 659 remove_inuse(dquot); 660 do_destroy_dquot(dquot); 661 count--; 662 head = free_dquots.prev; 663 } 664 } 665 666 /* 667 * This is called from kswapd when we think we need some 668 * more memory 669 */ 670 671 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 672 { 673 if (nr) { 674 spin_lock(&dq_list_lock); 675 prune_dqcache(nr); 676 spin_unlock(&dq_list_lock); 677 } 678 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure; 679 } 680 681 static struct shrinker dqcache_shrinker = { 682 .shrink = shrink_dqcache_memory, 683 .seeks = DEFAULT_SEEKS, 684 }; 685 686 /* 687 * Put reference to dquot 688 * NOTE: If you change this function please check whether dqput_blocks() works right... 689 */ 690 void dqput(struct dquot *dquot) 691 { 692 int ret; 693 694 if (!dquot) 695 return; 696 #ifdef CONFIG_QUOTA_DEBUG 697 if (!atomic_read(&dquot->dq_count)) { 698 printk("VFS: dqput: trying to free free dquot\n"); 699 printk("VFS: device %s, dquot of %s %d\n", 700 dquot->dq_sb->s_id, 701 quotatypes[dquot->dq_type], 702 dquot->dq_id); 703 BUG(); 704 } 705 #endif 706 707 spin_lock(&dq_list_lock); 708 dqstats.drops++; 709 spin_unlock(&dq_list_lock); 710 we_slept: 711 spin_lock(&dq_list_lock); 712 if (atomic_read(&dquot->dq_count) > 1) { 713 /* We have more than one user... nothing to do */ 714 atomic_dec(&dquot->dq_count); 715 /* Releasing dquot during quotaoff phase? */ 716 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_type) && 717 atomic_read(&dquot->dq_count) == 1) 718 wake_up(&dquot->dq_wait_unused); 719 spin_unlock(&dq_list_lock); 720 return; 721 } 722 /* Need to release dquot? */ 723 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 724 spin_unlock(&dq_list_lock); 725 /* Commit dquot before releasing */ 726 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 727 if (ret < 0) { 728 printk(KERN_ERR "VFS: cannot write quota structure on " 729 "device %s (error %d). Quota may get out of " 730 "sync!\n", dquot->dq_sb->s_id, ret); 731 /* 732 * We clear dirty bit anyway, so that we avoid 733 * infinite loop here 734 */ 735 spin_lock(&dq_list_lock); 736 clear_dquot_dirty(dquot); 737 spin_unlock(&dq_list_lock); 738 } 739 goto we_slept; 740 } 741 /* Clear flag in case dquot was inactive (something bad happened) */ 742 clear_dquot_dirty(dquot); 743 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 744 spin_unlock(&dq_list_lock); 745 dquot->dq_sb->dq_op->release_dquot(dquot); 746 goto we_slept; 747 } 748 atomic_dec(&dquot->dq_count); 749 #ifdef CONFIG_QUOTA_DEBUG 750 /* sanity check */ 751 BUG_ON(!list_empty(&dquot->dq_free)); 752 #endif 753 put_dquot_last(dquot); 754 spin_unlock(&dq_list_lock); 755 } 756 EXPORT_SYMBOL(dqput); 757 758 struct dquot *dquot_alloc(struct super_block *sb, int type) 759 { 760 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 761 } 762 EXPORT_SYMBOL(dquot_alloc); 763 764 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 765 { 766 struct dquot *dquot; 767 768 dquot = sb->dq_op->alloc_dquot(sb, type); 769 if(!dquot) 770 return NULL; 771 772 mutex_init(&dquot->dq_lock); 773 INIT_LIST_HEAD(&dquot->dq_free); 774 INIT_LIST_HEAD(&dquot->dq_inuse); 775 INIT_HLIST_NODE(&dquot->dq_hash); 776 INIT_LIST_HEAD(&dquot->dq_dirty); 777 init_waitqueue_head(&dquot->dq_wait_unused); 778 dquot->dq_sb = sb; 779 dquot->dq_type = type; 780 atomic_set(&dquot->dq_count, 1); 781 782 return dquot; 783 } 784 785 /* 786 * Get reference to dquot 787 * 788 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 789 * destroying our dquot by: 790 * a) checking for quota flags under dq_list_lock and 791 * b) getting a reference to dquot before we release dq_list_lock 792 */ 793 struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 794 { 795 unsigned int hashent = hashfn(sb, id, type); 796 struct dquot *dquot = NULL, *empty = NULL; 797 798 if (!sb_has_quota_active(sb, type)) 799 return NULL; 800 we_slept: 801 spin_lock(&dq_list_lock); 802 spin_lock(&dq_state_lock); 803 if (!sb_has_quota_active(sb, type)) { 804 spin_unlock(&dq_state_lock); 805 spin_unlock(&dq_list_lock); 806 goto out; 807 } 808 spin_unlock(&dq_state_lock); 809 810 dquot = find_dquot(hashent, sb, id, type); 811 if (!dquot) { 812 if (!empty) { 813 spin_unlock(&dq_list_lock); 814 empty = get_empty_dquot(sb, type); 815 if (!empty) 816 schedule(); /* Try to wait for a moment... */ 817 goto we_slept; 818 } 819 dquot = empty; 820 empty = NULL; 821 dquot->dq_id = id; 822 /* all dquots go on the inuse_list */ 823 put_inuse(dquot); 824 /* hash it first so it can be found */ 825 insert_dquot_hash(dquot); 826 dqstats.lookups++; 827 spin_unlock(&dq_list_lock); 828 } else { 829 if (!atomic_read(&dquot->dq_count)) 830 remove_free_dquot(dquot); 831 atomic_inc(&dquot->dq_count); 832 dqstats.cache_hits++; 833 dqstats.lookups++; 834 spin_unlock(&dq_list_lock); 835 } 836 /* Wait for dq_lock - after this we know that either dquot_release() is 837 * already finished or it will be canceled due to dq_count > 1 test */ 838 wait_on_dquot(dquot); 839 /* Read the dquot / allocate space in quota file */ 840 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 841 sb->dq_op->acquire_dquot(dquot) < 0) { 842 dqput(dquot); 843 dquot = NULL; 844 goto out; 845 } 846 #ifdef CONFIG_QUOTA_DEBUG 847 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 848 #endif 849 out: 850 if (empty) 851 do_destroy_dquot(empty); 852 853 return dquot; 854 } 855 EXPORT_SYMBOL(dqget); 856 857 static int dqinit_needed(struct inode *inode, int type) 858 { 859 int cnt; 860 861 if (IS_NOQUOTA(inode)) 862 return 0; 863 if (type != -1) 864 return !inode->i_dquot[type]; 865 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 866 if (!inode->i_dquot[cnt]) 867 return 1; 868 return 0; 869 } 870 871 /* This routine is guarded by dqonoff_mutex mutex */ 872 static void add_dquot_ref(struct super_block *sb, int type) 873 { 874 struct inode *inode, *old_inode = NULL; 875 #ifdef CONFIG_QUOTA_DEBUG 876 int reserved = 0; 877 #endif 878 879 spin_lock(&inode_lock); 880 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 881 if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) 882 continue; 883 #ifdef CONFIG_QUOTA_DEBUG 884 if (unlikely(inode_get_rsv_space(inode) > 0)) 885 reserved = 1; 886 #endif 887 if (!atomic_read(&inode->i_writecount)) 888 continue; 889 if (!dqinit_needed(inode, type)) 890 continue; 891 892 __iget(inode); 893 spin_unlock(&inode_lock); 894 895 iput(old_inode); 896 __dquot_initialize(inode, type); 897 /* We hold a reference to 'inode' so it couldn't have been 898 * removed from s_inodes list while we dropped the inode_lock. 899 * We cannot iput the inode now as we can be holding the last 900 * reference and we cannot iput it under inode_lock. So we 901 * keep the reference and iput it later. */ 902 old_inode = inode; 903 spin_lock(&inode_lock); 904 } 905 spin_unlock(&inode_lock); 906 iput(old_inode); 907 908 #ifdef CONFIG_QUOTA_DEBUG 909 if (reserved) { 910 printk(KERN_WARNING "VFS (%s): Writes happened before quota" 911 " was turned on thus quota information is probably " 912 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 913 } 914 #endif 915 } 916 917 /* 918 * Return 0 if dqput() won't block. 919 * (note that 1 doesn't necessarily mean blocking) 920 */ 921 static inline int dqput_blocks(struct dquot *dquot) 922 { 923 if (atomic_read(&dquot->dq_count) <= 1) 924 return 1; 925 return 0; 926 } 927 928 /* 929 * Remove references to dquots from inode and add dquot to list for freeing 930 * if we have the last referece to dquot 931 * We can't race with anybody because we hold dqptr_sem for writing... 932 */ 933 static int remove_inode_dquot_ref(struct inode *inode, int type, 934 struct list_head *tofree_head) 935 { 936 struct dquot *dquot = inode->i_dquot[type]; 937 938 inode->i_dquot[type] = NULL; 939 if (dquot) { 940 if (dqput_blocks(dquot)) { 941 #ifdef CONFIG_QUOTA_DEBUG 942 if (atomic_read(&dquot->dq_count) != 1) 943 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); 944 #endif 945 spin_lock(&dq_list_lock); 946 /* As dquot must have currently users it can't be on 947 * the free list... */ 948 list_add(&dquot->dq_free, tofree_head); 949 spin_unlock(&dq_list_lock); 950 return 1; 951 } 952 else 953 dqput(dquot); /* We have guaranteed we won't block */ 954 } 955 return 0; 956 } 957 958 /* 959 * Free list of dquots 960 * Dquots are removed from inodes and no new references can be got so we are 961 * the only ones holding reference 962 */ 963 static void put_dquot_list(struct list_head *tofree_head) 964 { 965 struct list_head *act_head; 966 struct dquot *dquot; 967 968 act_head = tofree_head->next; 969 while (act_head != tofree_head) { 970 dquot = list_entry(act_head, struct dquot, dq_free); 971 act_head = act_head->next; 972 /* Remove dquot from the list so we won't have problems... */ 973 list_del_init(&dquot->dq_free); 974 dqput(dquot); 975 } 976 } 977 978 static void remove_dquot_ref(struct super_block *sb, int type, 979 struct list_head *tofree_head) 980 { 981 struct inode *inode; 982 983 spin_lock(&inode_lock); 984 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 985 /* 986 * We have to scan also I_NEW inodes because they can already 987 * have quota pointer initialized. Luckily, we need to touch 988 * only quota pointers and these have separate locking 989 * (dqptr_sem). 990 */ 991 if (!IS_NOQUOTA(inode)) 992 remove_inode_dquot_ref(inode, type, tofree_head); 993 } 994 spin_unlock(&inode_lock); 995 } 996 997 /* Gather all references from inodes and drop them */ 998 static void drop_dquot_ref(struct super_block *sb, int type) 999 { 1000 LIST_HEAD(tofree_head); 1001 1002 if (sb->dq_op) { 1003 down_write(&sb_dqopt(sb)->dqptr_sem); 1004 remove_dquot_ref(sb, type, &tofree_head); 1005 up_write(&sb_dqopt(sb)->dqptr_sem); 1006 put_dquot_list(&tofree_head); 1007 } 1008 } 1009 1010 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1011 { 1012 dquot->dq_dqb.dqb_curinodes += number; 1013 } 1014 1015 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1016 { 1017 dquot->dq_dqb.dqb_curspace += number; 1018 } 1019 1020 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1021 { 1022 dquot->dq_dqb.dqb_rsvspace += number; 1023 } 1024 1025 /* 1026 * Claim reserved quota space 1027 */ 1028 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1029 { 1030 if (dquot->dq_dqb.dqb_rsvspace < number) { 1031 WARN_ON_ONCE(1); 1032 number = dquot->dq_dqb.dqb_rsvspace; 1033 } 1034 dquot->dq_dqb.dqb_curspace += number; 1035 dquot->dq_dqb.dqb_rsvspace -= number; 1036 } 1037 1038 static inline 1039 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1040 { 1041 if (dquot->dq_dqb.dqb_rsvspace >= number) 1042 dquot->dq_dqb.dqb_rsvspace -= number; 1043 else { 1044 WARN_ON_ONCE(1); 1045 dquot->dq_dqb.dqb_rsvspace = 0; 1046 } 1047 } 1048 1049 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1050 { 1051 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1052 dquot->dq_dqb.dqb_curinodes >= number) 1053 dquot->dq_dqb.dqb_curinodes -= number; 1054 else 1055 dquot->dq_dqb.dqb_curinodes = 0; 1056 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1057 dquot->dq_dqb.dqb_itime = (time_t) 0; 1058 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1059 } 1060 1061 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1062 { 1063 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1064 dquot->dq_dqb.dqb_curspace >= number) 1065 dquot->dq_dqb.dqb_curspace -= number; 1066 else 1067 dquot->dq_dqb.dqb_curspace = 0; 1068 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1069 dquot->dq_dqb.dqb_btime = (time_t) 0; 1070 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1071 } 1072 1073 static int warning_issued(struct dquot *dquot, const int warntype) 1074 { 1075 int flag = (warntype == QUOTA_NL_BHARDWARN || 1076 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1077 ((warntype == QUOTA_NL_IHARDWARN || 1078 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1079 1080 if (!flag) 1081 return 0; 1082 return test_and_set_bit(flag, &dquot->dq_flags); 1083 } 1084 1085 #ifdef CONFIG_PRINT_QUOTA_WARNING 1086 static int flag_print_warnings = 1; 1087 1088 static int need_print_warning(struct dquot *dquot) 1089 { 1090 if (!flag_print_warnings) 1091 return 0; 1092 1093 switch (dquot->dq_type) { 1094 case USRQUOTA: 1095 return current_fsuid() == dquot->dq_id; 1096 case GRPQUOTA: 1097 return in_group_p(dquot->dq_id); 1098 } 1099 return 0; 1100 } 1101 1102 /* Print warning to user which exceeded quota */ 1103 static void print_warning(struct dquot *dquot, const int warntype) 1104 { 1105 char *msg = NULL; 1106 struct tty_struct *tty; 1107 1108 if (warntype == QUOTA_NL_IHARDBELOW || 1109 warntype == QUOTA_NL_ISOFTBELOW || 1110 warntype == QUOTA_NL_BHARDBELOW || 1111 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 1112 return; 1113 1114 tty = get_current_tty(); 1115 if (!tty) 1116 return; 1117 tty_write_message(tty, dquot->dq_sb->s_id); 1118 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1119 tty_write_message(tty, ": warning, "); 1120 else 1121 tty_write_message(tty, ": write failed, "); 1122 tty_write_message(tty, quotatypes[dquot->dq_type]); 1123 switch (warntype) { 1124 case QUOTA_NL_IHARDWARN: 1125 msg = " file limit reached.\r\n"; 1126 break; 1127 case QUOTA_NL_ISOFTLONGWARN: 1128 msg = " file quota exceeded too long.\r\n"; 1129 break; 1130 case QUOTA_NL_ISOFTWARN: 1131 msg = " file quota exceeded.\r\n"; 1132 break; 1133 case QUOTA_NL_BHARDWARN: 1134 msg = " block limit reached.\r\n"; 1135 break; 1136 case QUOTA_NL_BSOFTLONGWARN: 1137 msg = " block quota exceeded too long.\r\n"; 1138 break; 1139 case QUOTA_NL_BSOFTWARN: 1140 msg = " block quota exceeded.\r\n"; 1141 break; 1142 } 1143 tty_write_message(tty, msg); 1144 tty_kref_put(tty); 1145 } 1146 #endif 1147 1148 /* 1149 * Write warnings to the console and send warning messages over netlink. 1150 * 1151 * Note that this function can sleep. 1152 */ 1153 static void flush_warnings(struct dquot *const *dquots, char *warntype) 1154 { 1155 struct dquot *dq; 1156 int i; 1157 1158 for (i = 0; i < MAXQUOTAS; i++) { 1159 dq = dquots[i]; 1160 if (dq && warntype[i] != QUOTA_NL_NOWARN && 1161 !warning_issued(dq, warntype[i])) { 1162 #ifdef CONFIG_PRINT_QUOTA_WARNING 1163 print_warning(dq, warntype[i]); 1164 #endif 1165 quota_send_warning(dq->dq_type, dq->dq_id, 1166 dq->dq_sb->s_dev, warntype[i]); 1167 } 1168 } 1169 } 1170 1171 static int ignore_hardlimit(struct dquot *dquot) 1172 { 1173 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1174 1175 return capable(CAP_SYS_RESOURCE) && 1176 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1177 !(info->dqi_flags & V1_DQF_RSQUASH)); 1178 } 1179 1180 /* needs dq_data_lock */ 1181 static int check_idq(struct dquot *dquot, qsize_t inodes, char *warntype) 1182 { 1183 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1184 1185 *warntype = QUOTA_NL_NOWARN; 1186 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type) || 1187 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1188 return 0; 1189 1190 if (dquot->dq_dqb.dqb_ihardlimit && 1191 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1192 !ignore_hardlimit(dquot)) { 1193 *warntype = QUOTA_NL_IHARDWARN; 1194 return -EDQUOT; 1195 } 1196 1197 if (dquot->dq_dqb.dqb_isoftlimit && 1198 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1199 dquot->dq_dqb.dqb_itime && 1200 get_seconds() >= dquot->dq_dqb.dqb_itime && 1201 !ignore_hardlimit(dquot)) { 1202 *warntype = QUOTA_NL_ISOFTLONGWARN; 1203 return -EDQUOT; 1204 } 1205 1206 if (dquot->dq_dqb.dqb_isoftlimit && 1207 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1208 dquot->dq_dqb.dqb_itime == 0) { 1209 *warntype = QUOTA_NL_ISOFTWARN; 1210 dquot->dq_dqb.dqb_itime = get_seconds() + 1211 sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1212 } 1213 1214 return 0; 1215 } 1216 1217 /* needs dq_data_lock */ 1218 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1219 { 1220 qsize_t tspace; 1221 struct super_block *sb = dquot->dq_sb; 1222 1223 *warntype = QUOTA_NL_NOWARN; 1224 if (!sb_has_quota_limits_enabled(sb, dquot->dq_type) || 1225 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1226 return 0; 1227 1228 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1229 + space; 1230 1231 if (dquot->dq_dqb.dqb_bhardlimit && 1232 tspace > dquot->dq_dqb.dqb_bhardlimit && 1233 !ignore_hardlimit(dquot)) { 1234 if (!prealloc) 1235 *warntype = QUOTA_NL_BHARDWARN; 1236 return -EDQUOT; 1237 } 1238 1239 if (dquot->dq_dqb.dqb_bsoftlimit && 1240 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1241 dquot->dq_dqb.dqb_btime && 1242 get_seconds() >= dquot->dq_dqb.dqb_btime && 1243 !ignore_hardlimit(dquot)) { 1244 if (!prealloc) 1245 *warntype = QUOTA_NL_BSOFTLONGWARN; 1246 return -EDQUOT; 1247 } 1248 1249 if (dquot->dq_dqb.dqb_bsoftlimit && 1250 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1251 dquot->dq_dqb.dqb_btime == 0) { 1252 if (!prealloc) { 1253 *warntype = QUOTA_NL_BSOFTWARN; 1254 dquot->dq_dqb.dqb_btime = get_seconds() + 1255 sb_dqopt(sb)->info[dquot->dq_type].dqi_bgrace; 1256 } 1257 else 1258 /* 1259 * We don't allow preallocation to exceed softlimit so exceeding will 1260 * be always printed 1261 */ 1262 return -EDQUOT; 1263 } 1264 1265 return 0; 1266 } 1267 1268 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1269 { 1270 qsize_t newinodes; 1271 1272 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1273 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1274 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_type)) 1275 return QUOTA_NL_NOWARN; 1276 1277 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1278 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1279 return QUOTA_NL_ISOFTBELOW; 1280 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1281 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1282 return QUOTA_NL_IHARDBELOW; 1283 return QUOTA_NL_NOWARN; 1284 } 1285 1286 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1287 { 1288 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1289 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1290 return QUOTA_NL_NOWARN; 1291 1292 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1293 return QUOTA_NL_BSOFTBELOW; 1294 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1295 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1296 return QUOTA_NL_BHARDBELOW; 1297 return QUOTA_NL_NOWARN; 1298 } 1299 1300 /* 1301 * Initialize quota pointers in inode 1302 * 1303 * We do things in a bit complicated way but by that we avoid calling 1304 * dqget() and thus filesystem callbacks under dqptr_sem. 1305 * 1306 * It is better to call this function outside of any transaction as it 1307 * might need a lot of space in journal for dquot structure allocation. 1308 */ 1309 static void __dquot_initialize(struct inode *inode, int type) 1310 { 1311 unsigned int id = 0; 1312 int cnt; 1313 struct dquot *got[MAXQUOTAS]; 1314 struct super_block *sb = inode->i_sb; 1315 qsize_t rsv; 1316 1317 /* First test before acquiring mutex - solves deadlocks when we 1318 * re-enter the quota code and are already holding the mutex */ 1319 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1320 return; 1321 1322 /* First get references to structures we might need. */ 1323 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1324 got[cnt] = NULL; 1325 if (type != -1 && cnt != type) 1326 continue; 1327 switch (cnt) { 1328 case USRQUOTA: 1329 id = inode->i_uid; 1330 break; 1331 case GRPQUOTA: 1332 id = inode->i_gid; 1333 break; 1334 } 1335 got[cnt] = dqget(sb, id, cnt); 1336 } 1337 1338 down_write(&sb_dqopt(sb)->dqptr_sem); 1339 if (IS_NOQUOTA(inode)) 1340 goto out_err; 1341 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1342 if (type != -1 && cnt != type) 1343 continue; 1344 /* Avoid races with quotaoff() */ 1345 if (!sb_has_quota_active(sb, cnt)) 1346 continue; 1347 if (!inode->i_dquot[cnt]) { 1348 inode->i_dquot[cnt] = got[cnt]; 1349 got[cnt] = NULL; 1350 /* 1351 * Make quota reservation system happy if someone 1352 * did a write before quota was turned on 1353 */ 1354 rsv = inode_get_rsv_space(inode); 1355 if (unlikely(rsv)) 1356 dquot_resv_space(inode->i_dquot[cnt], rsv); 1357 } 1358 } 1359 out_err: 1360 up_write(&sb_dqopt(sb)->dqptr_sem); 1361 /* Drop unused references */ 1362 dqput_all(got); 1363 } 1364 1365 void dquot_initialize(struct inode *inode) 1366 { 1367 __dquot_initialize(inode, -1); 1368 } 1369 EXPORT_SYMBOL(dquot_initialize); 1370 1371 /* 1372 * Release all quotas referenced by inode 1373 */ 1374 static void __dquot_drop(struct inode *inode) 1375 { 1376 int cnt; 1377 struct dquot *put[MAXQUOTAS]; 1378 1379 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1380 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1381 put[cnt] = inode->i_dquot[cnt]; 1382 inode->i_dquot[cnt] = NULL; 1383 } 1384 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1385 dqput_all(put); 1386 } 1387 1388 void dquot_drop(struct inode *inode) 1389 { 1390 int cnt; 1391 1392 if (IS_NOQUOTA(inode)) 1393 return; 1394 1395 /* 1396 * Test before calling to rule out calls from proc and such 1397 * where we are not allowed to block. Note that this is 1398 * actually reliable test even without the lock - the caller 1399 * must assure that nobody can come after the DQUOT_DROP and 1400 * add quota pointers back anyway. 1401 */ 1402 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1403 if (inode->i_dquot[cnt]) 1404 break; 1405 } 1406 1407 if (cnt < MAXQUOTAS) 1408 __dquot_drop(inode); 1409 } 1410 EXPORT_SYMBOL(dquot_drop); 1411 1412 /* 1413 * inode_reserved_space is managed internally by quota, and protected by 1414 * i_lock similar to i_blocks+i_bytes. 1415 */ 1416 static qsize_t *inode_reserved_space(struct inode * inode) 1417 { 1418 /* Filesystem must explicitly define it's own method in order to use 1419 * quota reservation interface */ 1420 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1421 return inode->i_sb->dq_op->get_reserved_space(inode); 1422 } 1423 1424 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1425 { 1426 spin_lock(&inode->i_lock); 1427 *inode_reserved_space(inode) += number; 1428 spin_unlock(&inode->i_lock); 1429 } 1430 EXPORT_SYMBOL(inode_add_rsv_space); 1431 1432 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1433 { 1434 spin_lock(&inode->i_lock); 1435 *inode_reserved_space(inode) -= number; 1436 __inode_add_bytes(inode, number); 1437 spin_unlock(&inode->i_lock); 1438 } 1439 EXPORT_SYMBOL(inode_claim_rsv_space); 1440 1441 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1442 { 1443 spin_lock(&inode->i_lock); 1444 *inode_reserved_space(inode) -= number; 1445 spin_unlock(&inode->i_lock); 1446 } 1447 EXPORT_SYMBOL(inode_sub_rsv_space); 1448 1449 static qsize_t inode_get_rsv_space(struct inode *inode) 1450 { 1451 qsize_t ret; 1452 1453 if (!inode->i_sb->dq_op->get_reserved_space) 1454 return 0; 1455 spin_lock(&inode->i_lock); 1456 ret = *inode_reserved_space(inode); 1457 spin_unlock(&inode->i_lock); 1458 return ret; 1459 } 1460 1461 static void inode_incr_space(struct inode *inode, qsize_t number, 1462 int reserve) 1463 { 1464 if (reserve) 1465 inode_add_rsv_space(inode, number); 1466 else 1467 inode_add_bytes(inode, number); 1468 } 1469 1470 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1471 { 1472 if (reserve) 1473 inode_sub_rsv_space(inode, number); 1474 else 1475 inode_sub_bytes(inode, number); 1476 } 1477 1478 /* 1479 * This functions updates i_blocks+i_bytes fields and quota information 1480 * (together with appropriate checks). 1481 * 1482 * NOTE: We absolutely rely on the fact that caller dirties the inode 1483 * (usually helpers in quotaops.h care about this) and holds a handle for 1484 * the current transaction so that dquot write and inode write go into the 1485 * same transaction. 1486 */ 1487 1488 /* 1489 * This operation can block, but only after everything is updated 1490 */ 1491 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1492 { 1493 int cnt, ret = 0; 1494 char warntype[MAXQUOTAS]; 1495 int warn = flags & DQUOT_SPACE_WARN; 1496 int reserve = flags & DQUOT_SPACE_RESERVE; 1497 int nofail = flags & DQUOT_SPACE_NOFAIL; 1498 1499 /* 1500 * First test before acquiring mutex - solves deadlocks when we 1501 * re-enter the quota code and are already holding the mutex 1502 */ 1503 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1504 inode_incr_space(inode, number, reserve); 1505 goto out; 1506 } 1507 1508 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1509 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1510 warntype[cnt] = QUOTA_NL_NOWARN; 1511 1512 spin_lock(&dq_data_lock); 1513 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1514 if (!inode->i_dquot[cnt]) 1515 continue; 1516 ret = check_bdq(inode->i_dquot[cnt], number, !warn, 1517 warntype+cnt); 1518 if (ret && !nofail) { 1519 spin_unlock(&dq_data_lock); 1520 goto out_flush_warn; 1521 } 1522 } 1523 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1524 if (!inode->i_dquot[cnt]) 1525 continue; 1526 if (reserve) 1527 dquot_resv_space(inode->i_dquot[cnt], number); 1528 else 1529 dquot_incr_space(inode->i_dquot[cnt], number); 1530 } 1531 inode_incr_space(inode, number, reserve); 1532 spin_unlock(&dq_data_lock); 1533 1534 if (reserve) 1535 goto out_flush_warn; 1536 mark_all_dquot_dirty(inode->i_dquot); 1537 out_flush_warn: 1538 flush_warnings(inode->i_dquot, warntype); 1539 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1540 out: 1541 return ret; 1542 } 1543 EXPORT_SYMBOL(__dquot_alloc_space); 1544 1545 /* 1546 * This operation can block, but only after everything is updated 1547 */ 1548 int dquot_alloc_inode(const struct inode *inode) 1549 { 1550 int cnt, ret = 0; 1551 char warntype[MAXQUOTAS]; 1552 1553 /* First test before acquiring mutex - solves deadlocks when we 1554 * re-enter the quota code and are already holding the mutex */ 1555 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1556 return 0; 1557 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1558 warntype[cnt] = QUOTA_NL_NOWARN; 1559 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1560 spin_lock(&dq_data_lock); 1561 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1562 if (!inode->i_dquot[cnt]) 1563 continue; 1564 ret = check_idq(inode->i_dquot[cnt], 1, warntype + cnt); 1565 if (ret) 1566 goto warn_put_all; 1567 } 1568 1569 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1570 if (!inode->i_dquot[cnt]) 1571 continue; 1572 dquot_incr_inodes(inode->i_dquot[cnt], 1); 1573 } 1574 1575 warn_put_all: 1576 spin_unlock(&dq_data_lock); 1577 if (ret == 0) 1578 mark_all_dquot_dirty(inode->i_dquot); 1579 flush_warnings(inode->i_dquot, warntype); 1580 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1581 return ret; 1582 } 1583 EXPORT_SYMBOL(dquot_alloc_inode); 1584 1585 /* 1586 * Convert in-memory reserved quotas to real consumed quotas 1587 */ 1588 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1589 { 1590 int cnt; 1591 1592 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1593 inode_claim_rsv_space(inode, number); 1594 return 0; 1595 } 1596 1597 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1598 spin_lock(&dq_data_lock); 1599 /* Claim reserved quotas to allocated quotas */ 1600 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1601 if (inode->i_dquot[cnt]) 1602 dquot_claim_reserved_space(inode->i_dquot[cnt], 1603 number); 1604 } 1605 /* Update inode bytes */ 1606 inode_claim_rsv_space(inode, number); 1607 spin_unlock(&dq_data_lock); 1608 mark_all_dquot_dirty(inode->i_dquot); 1609 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1610 return 0; 1611 } 1612 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1613 1614 /* 1615 * This operation can block, but only after everything is updated 1616 */ 1617 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1618 { 1619 unsigned int cnt; 1620 char warntype[MAXQUOTAS]; 1621 int reserve = flags & DQUOT_SPACE_RESERVE; 1622 1623 /* First test before acquiring mutex - solves deadlocks when we 1624 * re-enter the quota code and are already holding the mutex */ 1625 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) { 1626 inode_decr_space(inode, number, reserve); 1627 return; 1628 } 1629 1630 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1631 spin_lock(&dq_data_lock); 1632 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1633 if (!inode->i_dquot[cnt]) 1634 continue; 1635 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1636 if (reserve) 1637 dquot_free_reserved_space(inode->i_dquot[cnt], number); 1638 else 1639 dquot_decr_space(inode->i_dquot[cnt], number); 1640 } 1641 inode_decr_space(inode, number, reserve); 1642 spin_unlock(&dq_data_lock); 1643 1644 if (reserve) 1645 goto out_unlock; 1646 mark_all_dquot_dirty(inode->i_dquot); 1647 out_unlock: 1648 flush_warnings(inode->i_dquot, warntype); 1649 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1650 } 1651 EXPORT_SYMBOL(__dquot_free_space); 1652 1653 /* 1654 * This operation can block, but only after everything is updated 1655 */ 1656 void dquot_free_inode(const struct inode *inode) 1657 { 1658 unsigned int cnt; 1659 char warntype[MAXQUOTAS]; 1660 1661 /* First test before acquiring mutex - solves deadlocks when we 1662 * re-enter the quota code and are already holding the mutex */ 1663 if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) 1664 return; 1665 1666 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1667 spin_lock(&dq_data_lock); 1668 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1669 if (!inode->i_dquot[cnt]) 1670 continue; 1671 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], 1); 1672 dquot_decr_inodes(inode->i_dquot[cnt], 1); 1673 } 1674 spin_unlock(&dq_data_lock); 1675 mark_all_dquot_dirty(inode->i_dquot); 1676 flush_warnings(inode->i_dquot, warntype); 1677 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1678 } 1679 EXPORT_SYMBOL(dquot_free_inode); 1680 1681 /* 1682 * Transfer the number of inode and blocks from one diskquota to an other. 1683 * 1684 * This operation can block, but only after everything is updated 1685 * A transaction must be started when entering this function. 1686 */ 1687 static int __dquot_transfer(struct inode *inode, qid_t *chid, unsigned long mask) 1688 { 1689 qsize_t space, cur_space; 1690 qsize_t rsv_space = 0; 1691 struct dquot *transfer_from[MAXQUOTAS]; 1692 struct dquot *transfer_to[MAXQUOTAS]; 1693 int cnt, ret = 0; 1694 char warntype_to[MAXQUOTAS]; 1695 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1696 1697 /* First test before acquiring mutex - solves deadlocks when we 1698 * re-enter the quota code and are already holding the mutex */ 1699 if (IS_NOQUOTA(inode)) 1700 return 0; 1701 /* Initialize the arrays */ 1702 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1703 transfer_from[cnt] = NULL; 1704 transfer_to[cnt] = NULL; 1705 warntype_to[cnt] = QUOTA_NL_NOWARN; 1706 } 1707 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1708 if (mask & (1 << cnt)) 1709 transfer_to[cnt] = dqget(inode->i_sb, chid[cnt], cnt); 1710 } 1711 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1712 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1713 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1714 goto put_all; 1715 } 1716 spin_lock(&dq_data_lock); 1717 cur_space = inode_get_bytes(inode); 1718 rsv_space = inode_get_rsv_space(inode); 1719 space = cur_space + rsv_space; 1720 /* Build the transfer_from list and check the limits */ 1721 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1722 if (!transfer_to[cnt]) 1723 continue; 1724 transfer_from[cnt] = inode->i_dquot[cnt]; 1725 ret = check_idq(transfer_to[cnt], 1, warntype_to + cnt); 1726 if (ret) 1727 goto over_quota; 1728 ret = check_bdq(transfer_to[cnt], space, 0, warntype_to + cnt); 1729 if (ret) 1730 goto over_quota; 1731 } 1732 1733 /* 1734 * Finally perform the needed transfer from transfer_from to transfer_to 1735 */ 1736 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1737 /* 1738 * Skip changes for same uid or gid or for turned off quota-type. 1739 */ 1740 if (!transfer_to[cnt]) 1741 continue; 1742 1743 /* Due to IO error we might not have transfer_from[] structure */ 1744 if (transfer_from[cnt]) { 1745 warntype_from_inodes[cnt] = 1746 info_idq_free(transfer_from[cnt], 1); 1747 warntype_from_space[cnt] = 1748 info_bdq_free(transfer_from[cnt], space); 1749 dquot_decr_inodes(transfer_from[cnt], 1); 1750 dquot_decr_space(transfer_from[cnt], cur_space); 1751 dquot_free_reserved_space(transfer_from[cnt], 1752 rsv_space); 1753 } 1754 1755 dquot_incr_inodes(transfer_to[cnt], 1); 1756 dquot_incr_space(transfer_to[cnt], cur_space); 1757 dquot_resv_space(transfer_to[cnt], rsv_space); 1758 1759 inode->i_dquot[cnt] = transfer_to[cnt]; 1760 } 1761 spin_unlock(&dq_data_lock); 1762 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1763 1764 mark_all_dquot_dirty(transfer_from); 1765 mark_all_dquot_dirty(transfer_to); 1766 /* The reference we got is transferred to the inode */ 1767 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1768 transfer_to[cnt] = NULL; 1769 warn_put_all: 1770 flush_warnings(transfer_to, warntype_to); 1771 flush_warnings(transfer_from, warntype_from_inodes); 1772 flush_warnings(transfer_from, warntype_from_space); 1773 put_all: 1774 dqput_all(transfer_from); 1775 dqput_all(transfer_to); 1776 return ret; 1777 over_quota: 1778 spin_unlock(&dq_data_lock); 1779 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1780 /* Clear dquot pointers we don't want to dqput() */ 1781 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1782 transfer_from[cnt] = NULL; 1783 goto warn_put_all; 1784 } 1785 1786 /* Wrapper for transferring ownership of an inode for uid/gid only 1787 * Called from FSXXX_setattr() 1788 */ 1789 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1790 { 1791 qid_t chid[MAXQUOTAS]; 1792 unsigned long mask = 0; 1793 1794 if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) { 1795 mask |= 1 << USRQUOTA; 1796 chid[USRQUOTA] = iattr->ia_uid; 1797 } 1798 if (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid) { 1799 mask |= 1 << GRPQUOTA; 1800 chid[GRPQUOTA] = iattr->ia_gid; 1801 } 1802 if (sb_any_quota_active(inode->i_sb) && !IS_NOQUOTA(inode)) { 1803 dquot_initialize(inode); 1804 return __dquot_transfer(inode, chid, mask); 1805 } 1806 return 0; 1807 } 1808 EXPORT_SYMBOL(dquot_transfer); 1809 1810 /* 1811 * Write info of quota file to disk 1812 */ 1813 int dquot_commit_info(struct super_block *sb, int type) 1814 { 1815 int ret; 1816 struct quota_info *dqopt = sb_dqopt(sb); 1817 1818 mutex_lock(&dqopt->dqio_mutex); 1819 ret = dqopt->ops[type]->write_file_info(sb, type); 1820 mutex_unlock(&dqopt->dqio_mutex); 1821 return ret; 1822 } 1823 EXPORT_SYMBOL(dquot_commit_info); 1824 1825 /* 1826 * Definitions of diskquota operations. 1827 */ 1828 const struct dquot_operations dquot_operations = { 1829 .write_dquot = dquot_commit, 1830 .acquire_dquot = dquot_acquire, 1831 .release_dquot = dquot_release, 1832 .mark_dirty = dquot_mark_dquot_dirty, 1833 .write_info = dquot_commit_info, 1834 .alloc_dquot = dquot_alloc, 1835 .destroy_dquot = dquot_destroy, 1836 }; 1837 1838 /* 1839 * Generic helper for ->open on filesystems supporting disk quotas. 1840 */ 1841 int dquot_file_open(struct inode *inode, struct file *file) 1842 { 1843 int error; 1844 1845 error = generic_file_open(inode, file); 1846 if (!error && (file->f_mode & FMODE_WRITE)) 1847 dquot_initialize(inode); 1848 return error; 1849 } 1850 EXPORT_SYMBOL(dquot_file_open); 1851 1852 /* 1853 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1854 */ 1855 int vfs_quota_disable(struct super_block *sb, int type, unsigned int flags) 1856 { 1857 int cnt, ret = 0; 1858 struct quota_info *dqopt = sb_dqopt(sb); 1859 struct inode *toputinode[MAXQUOTAS]; 1860 1861 /* Cannot turn off usage accounting without turning off limits, or 1862 * suspend quotas and simultaneously turn quotas off. */ 1863 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 1864 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 1865 DQUOT_USAGE_ENABLED))) 1866 return -EINVAL; 1867 1868 /* We need to serialize quota_off() for device */ 1869 mutex_lock(&dqopt->dqonoff_mutex); 1870 1871 /* 1872 * Skip everything if there's nothing to do. We have to do this because 1873 * sometimes we are called when fill_super() failed and calling 1874 * sync_fs() in such cases does no good. 1875 */ 1876 if (!sb_any_quota_loaded(sb)) { 1877 mutex_unlock(&dqopt->dqonoff_mutex); 1878 return 0; 1879 } 1880 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1881 toputinode[cnt] = NULL; 1882 if (type != -1 && cnt != type) 1883 continue; 1884 if (!sb_has_quota_loaded(sb, cnt)) 1885 continue; 1886 1887 if (flags & DQUOT_SUSPENDED) { 1888 spin_lock(&dq_state_lock); 1889 dqopt->flags |= 1890 dquot_state_flag(DQUOT_SUSPENDED, cnt); 1891 spin_unlock(&dq_state_lock); 1892 } else { 1893 spin_lock(&dq_state_lock); 1894 dqopt->flags &= ~dquot_state_flag(flags, cnt); 1895 /* Turning off suspended quotas? */ 1896 if (!sb_has_quota_loaded(sb, cnt) && 1897 sb_has_quota_suspended(sb, cnt)) { 1898 dqopt->flags &= ~dquot_state_flag( 1899 DQUOT_SUSPENDED, cnt); 1900 spin_unlock(&dq_state_lock); 1901 iput(dqopt->files[cnt]); 1902 dqopt->files[cnt] = NULL; 1903 continue; 1904 } 1905 spin_unlock(&dq_state_lock); 1906 } 1907 1908 /* We still have to keep quota loaded? */ 1909 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 1910 continue; 1911 1912 /* Note: these are blocking operations */ 1913 drop_dquot_ref(sb, cnt); 1914 invalidate_dquots(sb, cnt); 1915 /* 1916 * Now all dquots should be invalidated, all writes done so we 1917 * should be only users of the info. No locks needed. 1918 */ 1919 if (info_dirty(&dqopt->info[cnt])) 1920 sb->dq_op->write_info(sb, cnt); 1921 if (dqopt->ops[cnt]->free_file_info) 1922 dqopt->ops[cnt]->free_file_info(sb, cnt); 1923 put_quota_format(dqopt->info[cnt].dqi_format); 1924 1925 toputinode[cnt] = dqopt->files[cnt]; 1926 if (!sb_has_quota_loaded(sb, cnt)) 1927 dqopt->files[cnt] = NULL; 1928 dqopt->info[cnt].dqi_flags = 0; 1929 dqopt->info[cnt].dqi_igrace = 0; 1930 dqopt->info[cnt].dqi_bgrace = 0; 1931 dqopt->ops[cnt] = NULL; 1932 } 1933 mutex_unlock(&dqopt->dqonoff_mutex); 1934 1935 /* Skip syncing and setting flags if quota files are hidden */ 1936 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 1937 goto put_inodes; 1938 1939 /* Sync the superblock so that buffers with quota data are written to 1940 * disk (and so userspace sees correct data afterwards). */ 1941 if (sb->s_op->sync_fs) 1942 sb->s_op->sync_fs(sb, 1); 1943 sync_blockdev(sb->s_bdev); 1944 /* Now the quota files are just ordinary files and we can set the 1945 * inode flags back. Moreover we discard the pagecache so that 1946 * userspace sees the writes we did bypassing the pagecache. We 1947 * must also discard the blockdev buffers so that we see the 1948 * changes done by userspace on the next quotaon() */ 1949 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1950 if (toputinode[cnt]) { 1951 mutex_lock(&dqopt->dqonoff_mutex); 1952 /* If quota was reenabled in the meantime, we have 1953 * nothing to do */ 1954 if (!sb_has_quota_loaded(sb, cnt)) { 1955 mutex_lock_nested(&toputinode[cnt]->i_mutex, 1956 I_MUTEX_QUOTA); 1957 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1958 S_NOATIME | S_NOQUOTA); 1959 truncate_inode_pages(&toputinode[cnt]->i_data, 1960 0); 1961 mutex_unlock(&toputinode[cnt]->i_mutex); 1962 mark_inode_dirty(toputinode[cnt]); 1963 } 1964 mutex_unlock(&dqopt->dqonoff_mutex); 1965 } 1966 if (sb->s_bdev) 1967 invalidate_bdev(sb->s_bdev); 1968 put_inodes: 1969 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1970 if (toputinode[cnt]) { 1971 /* On remount RO, we keep the inode pointer so that we 1972 * can reenable quota on the subsequent remount RW. We 1973 * have to check 'flags' variable and not use sb_has_ 1974 * function because another quotaon / quotaoff could 1975 * change global state before we got here. We refuse 1976 * to suspend quotas when there is pending delete on 1977 * the quota file... */ 1978 if (!(flags & DQUOT_SUSPENDED)) 1979 iput(toputinode[cnt]); 1980 else if (!toputinode[cnt]->i_nlink) 1981 ret = -EBUSY; 1982 } 1983 return ret; 1984 } 1985 EXPORT_SYMBOL(vfs_quota_disable); 1986 1987 int vfs_quota_off(struct super_block *sb, int type, int remount) 1988 { 1989 return vfs_quota_disable(sb, type, remount ? DQUOT_SUSPENDED : 1990 (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED)); 1991 } 1992 EXPORT_SYMBOL(vfs_quota_off); 1993 /* 1994 * Turn quotas on on a device 1995 */ 1996 1997 /* 1998 * Helper function to turn quotas on when we already have the inode of 1999 * quota file and no quota information is loaded. 2000 */ 2001 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2002 unsigned int flags) 2003 { 2004 struct quota_format_type *fmt = find_quota_format(format_id); 2005 struct super_block *sb = inode->i_sb; 2006 struct quota_info *dqopt = sb_dqopt(sb); 2007 int error; 2008 int oldflags = -1; 2009 2010 if (!fmt) 2011 return -ESRCH; 2012 if (!S_ISREG(inode->i_mode)) { 2013 error = -EACCES; 2014 goto out_fmt; 2015 } 2016 if (IS_RDONLY(inode)) { 2017 error = -EROFS; 2018 goto out_fmt; 2019 } 2020 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 2021 error = -EINVAL; 2022 goto out_fmt; 2023 } 2024 /* Usage always has to be set... */ 2025 if (!(flags & DQUOT_USAGE_ENABLED)) { 2026 error = -EINVAL; 2027 goto out_fmt; 2028 } 2029 2030 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2031 /* As we bypass the pagecache we must now flush all the 2032 * dirty data and invalidate caches so that kernel sees 2033 * changes from userspace. It is not enough to just flush 2034 * the quota file since if blocksize < pagesize, invalidation 2035 * of the cache could fail because of other unrelated dirty 2036 * data */ 2037 sync_filesystem(sb); 2038 invalidate_bdev(sb->s_bdev); 2039 } 2040 mutex_lock(&dqopt->dqonoff_mutex); 2041 if (sb_has_quota_loaded(sb, type)) { 2042 error = -EBUSY; 2043 goto out_lock; 2044 } 2045 2046 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2047 /* We don't want quota and atime on quota files (deadlocks 2048 * possible) Also nobody should write to the file - we use 2049 * special IO operations which ignore the immutable bit. */ 2050 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2051 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2052 S_NOQUOTA); 2053 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2054 mutex_unlock(&inode->i_mutex); 2055 /* 2056 * When S_NOQUOTA is set, remove dquot references as no more 2057 * references can be added 2058 */ 2059 __dquot_drop(inode); 2060 } 2061 2062 error = -EIO; 2063 dqopt->files[type] = igrab(inode); 2064 if (!dqopt->files[type]) 2065 goto out_lock; 2066 error = -EINVAL; 2067 if (!fmt->qf_ops->check_quota_file(sb, type)) 2068 goto out_file_init; 2069 2070 dqopt->ops[type] = fmt->qf_ops; 2071 dqopt->info[type].dqi_format = fmt; 2072 dqopt->info[type].dqi_fmt_id = format_id; 2073 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2074 mutex_lock(&dqopt->dqio_mutex); 2075 error = dqopt->ops[type]->read_file_info(sb, type); 2076 if (error < 0) { 2077 mutex_unlock(&dqopt->dqio_mutex); 2078 goto out_file_init; 2079 } 2080 mutex_unlock(&dqopt->dqio_mutex); 2081 spin_lock(&dq_state_lock); 2082 dqopt->flags |= dquot_state_flag(flags, type); 2083 spin_unlock(&dq_state_lock); 2084 2085 add_dquot_ref(sb, type); 2086 mutex_unlock(&dqopt->dqonoff_mutex); 2087 2088 return 0; 2089 2090 out_file_init: 2091 dqopt->files[type] = NULL; 2092 iput(inode); 2093 out_lock: 2094 if (oldflags != -1) { 2095 mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA); 2096 /* Set the flags back (in the case of accidental quotaon() 2097 * on a wrong file we don't want to mess up the flags) */ 2098 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2099 inode->i_flags |= oldflags; 2100 mutex_unlock(&inode->i_mutex); 2101 } 2102 mutex_unlock(&dqopt->dqonoff_mutex); 2103 out_fmt: 2104 put_quota_format(fmt); 2105 2106 return error; 2107 } 2108 2109 /* Reenable quotas on remount RW */ 2110 static int vfs_quota_on_remount(struct super_block *sb, int type) 2111 { 2112 struct quota_info *dqopt = sb_dqopt(sb); 2113 struct inode *inode; 2114 int ret; 2115 unsigned int flags; 2116 2117 mutex_lock(&dqopt->dqonoff_mutex); 2118 if (!sb_has_quota_suspended(sb, type)) { 2119 mutex_unlock(&dqopt->dqonoff_mutex); 2120 return 0; 2121 } 2122 inode = dqopt->files[type]; 2123 dqopt->files[type] = NULL; 2124 spin_lock(&dq_state_lock); 2125 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2126 DQUOT_LIMITS_ENABLED, type); 2127 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, type); 2128 spin_unlock(&dq_state_lock); 2129 mutex_unlock(&dqopt->dqonoff_mutex); 2130 2131 flags = dquot_generic_flag(flags, type); 2132 ret = vfs_load_quota_inode(inode, type, dqopt->info[type].dqi_fmt_id, 2133 flags); 2134 iput(inode); 2135 2136 return ret; 2137 } 2138 2139 int vfs_quota_on_path(struct super_block *sb, int type, int format_id, 2140 struct path *path) 2141 { 2142 int error = security_quota_on(path->dentry); 2143 if (error) 2144 return error; 2145 /* Quota file not on the same filesystem? */ 2146 if (path->mnt->mnt_sb != sb) 2147 error = -EXDEV; 2148 else 2149 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2150 format_id, DQUOT_USAGE_ENABLED | 2151 DQUOT_LIMITS_ENABLED); 2152 return error; 2153 } 2154 EXPORT_SYMBOL(vfs_quota_on_path); 2155 2156 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name, 2157 int remount) 2158 { 2159 struct path path; 2160 int error; 2161 2162 if (remount) 2163 return vfs_quota_on_remount(sb, type); 2164 2165 error = kern_path(name, LOOKUP_FOLLOW, &path); 2166 if (!error) { 2167 error = vfs_quota_on_path(sb, type, format_id, &path); 2168 path_put(&path); 2169 } 2170 return error; 2171 } 2172 EXPORT_SYMBOL(vfs_quota_on); 2173 2174 /* 2175 * More powerful function for turning on quotas allowing setting 2176 * of individual quota flags 2177 */ 2178 int vfs_quota_enable(struct inode *inode, int type, int format_id, 2179 unsigned int flags) 2180 { 2181 int ret = 0; 2182 struct super_block *sb = inode->i_sb; 2183 struct quota_info *dqopt = sb_dqopt(sb); 2184 2185 /* Just unsuspend quotas? */ 2186 if (flags & DQUOT_SUSPENDED) 2187 return vfs_quota_on_remount(sb, type); 2188 if (!flags) 2189 return 0; 2190 /* Just updating flags needed? */ 2191 if (sb_has_quota_loaded(sb, type)) { 2192 mutex_lock(&dqopt->dqonoff_mutex); 2193 /* Now do a reliable test... */ 2194 if (!sb_has_quota_loaded(sb, type)) { 2195 mutex_unlock(&dqopt->dqonoff_mutex); 2196 goto load_quota; 2197 } 2198 if (flags & DQUOT_USAGE_ENABLED && 2199 sb_has_quota_usage_enabled(sb, type)) { 2200 ret = -EBUSY; 2201 goto out_lock; 2202 } 2203 if (flags & DQUOT_LIMITS_ENABLED && 2204 sb_has_quota_limits_enabled(sb, type)) { 2205 ret = -EBUSY; 2206 goto out_lock; 2207 } 2208 spin_lock(&dq_state_lock); 2209 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2210 spin_unlock(&dq_state_lock); 2211 out_lock: 2212 mutex_unlock(&dqopt->dqonoff_mutex); 2213 return ret; 2214 } 2215 2216 load_quota: 2217 return vfs_load_quota_inode(inode, type, format_id, flags); 2218 } 2219 EXPORT_SYMBOL(vfs_quota_enable); 2220 2221 /* 2222 * This function is used when filesystem needs to initialize quotas 2223 * during mount time. 2224 */ 2225 int vfs_quota_on_mount(struct super_block *sb, char *qf_name, 2226 int format_id, int type) 2227 { 2228 struct dentry *dentry; 2229 int error; 2230 2231 mutex_lock(&sb->s_root->d_inode->i_mutex); 2232 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2233 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2234 if (IS_ERR(dentry)) 2235 return PTR_ERR(dentry); 2236 2237 if (!dentry->d_inode) { 2238 error = -ENOENT; 2239 goto out; 2240 } 2241 2242 error = security_quota_on(dentry); 2243 if (!error) 2244 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2245 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2246 2247 out: 2248 dput(dentry); 2249 return error; 2250 } 2251 EXPORT_SYMBOL(vfs_quota_on_mount); 2252 2253 /* Wrapper to turn on quotas when remounting rw */ 2254 int vfs_dq_quota_on_remount(struct super_block *sb) 2255 { 2256 int cnt; 2257 int ret = 0, err; 2258 2259 if (!sb->s_qcop || !sb->s_qcop->quota_on) 2260 return -ENOSYS; 2261 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2262 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1); 2263 if (err < 0 && !ret) 2264 ret = err; 2265 } 2266 return ret; 2267 } 2268 EXPORT_SYMBOL(vfs_dq_quota_on_remount); 2269 2270 static inline qsize_t qbtos(qsize_t blocks) 2271 { 2272 return blocks << QIF_DQBLKSIZE_BITS; 2273 } 2274 2275 static inline qsize_t stoqb(qsize_t space) 2276 { 2277 return (space + QIF_DQBLKSIZE - 1) >> QIF_DQBLKSIZE_BITS; 2278 } 2279 2280 /* Generic routine for getting common part of quota structure */ 2281 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di) 2282 { 2283 struct mem_dqblk *dm = &dquot->dq_dqb; 2284 2285 spin_lock(&dq_data_lock); 2286 di->dqb_bhardlimit = stoqb(dm->dqb_bhardlimit); 2287 di->dqb_bsoftlimit = stoqb(dm->dqb_bsoftlimit); 2288 di->dqb_curspace = dm->dqb_curspace + dm->dqb_rsvspace; 2289 di->dqb_ihardlimit = dm->dqb_ihardlimit; 2290 di->dqb_isoftlimit = dm->dqb_isoftlimit; 2291 di->dqb_curinodes = dm->dqb_curinodes; 2292 di->dqb_btime = dm->dqb_btime; 2293 di->dqb_itime = dm->dqb_itime; 2294 di->dqb_valid = QIF_ALL; 2295 spin_unlock(&dq_data_lock); 2296 } 2297 2298 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, 2299 struct if_dqblk *di) 2300 { 2301 struct dquot *dquot; 2302 2303 dquot = dqget(sb, id, type); 2304 if (!dquot) 2305 return -ESRCH; 2306 do_get_dqblk(dquot, di); 2307 dqput(dquot); 2308 2309 return 0; 2310 } 2311 EXPORT_SYMBOL(vfs_get_dqblk); 2312 2313 /* Generic routine for setting common part of quota structure */ 2314 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) 2315 { 2316 struct mem_dqblk *dm = &dquot->dq_dqb; 2317 int check_blim = 0, check_ilim = 0; 2318 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 2319 2320 if ((di->dqb_valid & QIF_BLIMITS && 2321 (di->dqb_bhardlimit > dqi->dqi_maxblimit || 2322 di->dqb_bsoftlimit > dqi->dqi_maxblimit)) || 2323 (di->dqb_valid & QIF_ILIMITS && 2324 (di->dqb_ihardlimit > dqi->dqi_maxilimit || 2325 di->dqb_isoftlimit > dqi->dqi_maxilimit))) 2326 return -ERANGE; 2327 2328 spin_lock(&dq_data_lock); 2329 if (di->dqb_valid & QIF_SPACE) { 2330 dm->dqb_curspace = di->dqb_curspace - dm->dqb_rsvspace; 2331 check_blim = 1; 2332 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2333 } 2334 if (di->dqb_valid & QIF_BLIMITS) { 2335 dm->dqb_bsoftlimit = qbtos(di->dqb_bsoftlimit); 2336 dm->dqb_bhardlimit = qbtos(di->dqb_bhardlimit); 2337 check_blim = 1; 2338 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2339 } 2340 if (di->dqb_valid & QIF_INODES) { 2341 dm->dqb_curinodes = di->dqb_curinodes; 2342 check_ilim = 1; 2343 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2344 } 2345 if (di->dqb_valid & QIF_ILIMITS) { 2346 dm->dqb_isoftlimit = di->dqb_isoftlimit; 2347 dm->dqb_ihardlimit = di->dqb_ihardlimit; 2348 check_ilim = 1; 2349 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2350 } 2351 if (di->dqb_valid & QIF_BTIME) { 2352 dm->dqb_btime = di->dqb_btime; 2353 check_blim = 1; 2354 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2355 } 2356 if (di->dqb_valid & QIF_ITIME) { 2357 dm->dqb_itime = di->dqb_itime; 2358 check_ilim = 1; 2359 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2360 } 2361 2362 if (check_blim) { 2363 if (!dm->dqb_bsoftlimit || 2364 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2365 dm->dqb_btime = 0; 2366 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2367 } else if (!(di->dqb_valid & QIF_BTIME)) 2368 /* Set grace only if user hasn't provided his own... */ 2369 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2370 } 2371 if (check_ilim) { 2372 if (!dm->dqb_isoftlimit || 2373 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2374 dm->dqb_itime = 0; 2375 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2376 } else if (!(di->dqb_valid & QIF_ITIME)) 2377 /* Set grace only if user hasn't provided his own... */ 2378 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2379 } 2380 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2381 dm->dqb_isoftlimit) 2382 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2383 else 2384 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2385 spin_unlock(&dq_data_lock); 2386 mark_dquot_dirty(dquot); 2387 2388 return 0; 2389 } 2390 2391 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, 2392 struct if_dqblk *di) 2393 { 2394 struct dquot *dquot; 2395 int rc; 2396 2397 dquot = dqget(sb, id, type); 2398 if (!dquot) { 2399 rc = -ESRCH; 2400 goto out; 2401 } 2402 rc = do_set_dqblk(dquot, di); 2403 dqput(dquot); 2404 out: 2405 return rc; 2406 } 2407 EXPORT_SYMBOL(vfs_set_dqblk); 2408 2409 /* Generic routine for getting common part of quota file information */ 2410 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2411 { 2412 struct mem_dqinfo *mi; 2413 2414 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2415 if (!sb_has_quota_active(sb, type)) { 2416 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2417 return -ESRCH; 2418 } 2419 mi = sb_dqopt(sb)->info + type; 2420 spin_lock(&dq_data_lock); 2421 ii->dqi_bgrace = mi->dqi_bgrace; 2422 ii->dqi_igrace = mi->dqi_igrace; 2423 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 2424 ii->dqi_valid = IIF_ALL; 2425 spin_unlock(&dq_data_lock); 2426 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2427 return 0; 2428 } 2429 EXPORT_SYMBOL(vfs_get_dqinfo); 2430 2431 /* Generic routine for setting common part of quota file information */ 2432 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2433 { 2434 struct mem_dqinfo *mi; 2435 int err = 0; 2436 2437 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2438 if (!sb_has_quota_active(sb, type)) { 2439 err = -ESRCH; 2440 goto out; 2441 } 2442 mi = sb_dqopt(sb)->info + type; 2443 spin_lock(&dq_data_lock); 2444 if (ii->dqi_valid & IIF_BGRACE) 2445 mi->dqi_bgrace = ii->dqi_bgrace; 2446 if (ii->dqi_valid & IIF_IGRACE) 2447 mi->dqi_igrace = ii->dqi_igrace; 2448 if (ii->dqi_valid & IIF_FLAGS) 2449 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | 2450 (ii->dqi_flags & DQF_MASK); 2451 spin_unlock(&dq_data_lock); 2452 mark_info_dirty(sb, type); 2453 /* Force write to disk */ 2454 sb->dq_op->write_info(sb, type); 2455 out: 2456 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2457 return err; 2458 } 2459 EXPORT_SYMBOL(vfs_set_dqinfo); 2460 2461 const struct quotactl_ops vfs_quotactl_ops = { 2462 .quota_on = vfs_quota_on, 2463 .quota_off = vfs_quota_off, 2464 .quota_sync = vfs_quota_sync, 2465 .get_info = vfs_get_dqinfo, 2466 .set_info = vfs_set_dqinfo, 2467 .get_dqblk = vfs_get_dqblk, 2468 .set_dqblk = vfs_set_dqblk 2469 }; 2470 2471 static ctl_table fs_dqstats_table[] = { 2472 { 2473 .procname = "lookups", 2474 .data = &dqstats.lookups, 2475 .maxlen = sizeof(int), 2476 .mode = 0444, 2477 .proc_handler = proc_dointvec, 2478 }, 2479 { 2480 .procname = "drops", 2481 .data = &dqstats.drops, 2482 .maxlen = sizeof(int), 2483 .mode = 0444, 2484 .proc_handler = proc_dointvec, 2485 }, 2486 { 2487 .procname = "reads", 2488 .data = &dqstats.reads, 2489 .maxlen = sizeof(int), 2490 .mode = 0444, 2491 .proc_handler = proc_dointvec, 2492 }, 2493 { 2494 .procname = "writes", 2495 .data = &dqstats.writes, 2496 .maxlen = sizeof(int), 2497 .mode = 0444, 2498 .proc_handler = proc_dointvec, 2499 }, 2500 { 2501 .procname = "cache_hits", 2502 .data = &dqstats.cache_hits, 2503 .maxlen = sizeof(int), 2504 .mode = 0444, 2505 .proc_handler = proc_dointvec, 2506 }, 2507 { 2508 .procname = "allocated_dquots", 2509 .data = &dqstats.allocated_dquots, 2510 .maxlen = sizeof(int), 2511 .mode = 0444, 2512 .proc_handler = proc_dointvec, 2513 }, 2514 { 2515 .procname = "free_dquots", 2516 .data = &dqstats.free_dquots, 2517 .maxlen = sizeof(int), 2518 .mode = 0444, 2519 .proc_handler = proc_dointvec, 2520 }, 2521 { 2522 .procname = "syncs", 2523 .data = &dqstats.syncs, 2524 .maxlen = sizeof(int), 2525 .mode = 0444, 2526 .proc_handler = proc_dointvec, 2527 }, 2528 #ifdef CONFIG_PRINT_QUOTA_WARNING 2529 { 2530 .procname = "warnings", 2531 .data = &flag_print_warnings, 2532 .maxlen = sizeof(int), 2533 .mode = 0644, 2534 .proc_handler = proc_dointvec, 2535 }, 2536 #endif 2537 { }, 2538 }; 2539 2540 static ctl_table fs_table[] = { 2541 { 2542 .procname = "quota", 2543 .mode = 0555, 2544 .child = fs_dqstats_table, 2545 }, 2546 { }, 2547 }; 2548 2549 static ctl_table sys_table[] = { 2550 { 2551 .procname = "fs", 2552 .mode = 0555, 2553 .child = fs_table, 2554 }, 2555 { }, 2556 }; 2557 2558 static int __init dquot_init(void) 2559 { 2560 int i; 2561 unsigned long nr_hash, order; 2562 2563 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2564 2565 register_sysctl_table(sys_table); 2566 2567 dquot_cachep = kmem_cache_create("dquot", 2568 sizeof(struct dquot), sizeof(unsigned long) * 4, 2569 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2570 SLAB_MEM_SPREAD|SLAB_PANIC), 2571 NULL); 2572 2573 order = 0; 2574 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2575 if (!dquot_hash) 2576 panic("Cannot create dquot hash table"); 2577 2578 /* Find power-of-two hlist_heads which can fit into allocation */ 2579 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2580 dq_hash_bits = 0; 2581 do { 2582 dq_hash_bits++; 2583 } while (nr_hash >> dq_hash_bits); 2584 dq_hash_bits--; 2585 2586 nr_hash = 1UL << dq_hash_bits; 2587 dq_hash_mask = nr_hash - 1; 2588 for (i = 0; i < nr_hash; i++) 2589 INIT_HLIST_HEAD(dquot_hash + i); 2590 2591 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2592 nr_hash, order, (PAGE_SIZE << order)); 2593 2594 register_shrinker(&dqcache_shrinker); 2595 2596 return 0; 2597 } 2598 module_init(dquot_init); 2599