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/sched.h> 75 #include <linux/kmod.h> 76 #include <linux/namei.h> 77 #include <linux/capability.h> 78 #include <linux/quotaops.h> 79 #include "../internal.h" /* ugh */ 80 81 #include <linux/uaccess.h> 82 83 /* 84 * There are three quota SMP locks. dq_list_lock protects all lists with quotas 85 * and quota formats. 86 * dq_data_lock protects data from dq_dqb and also mem_dqinfo structures and 87 * also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes. 88 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly 89 * in inode_add_bytes() and inode_sub_bytes(). dq_state_lock protects 90 * modifications of quota state (on quotaon and quotaoff) and readers who care 91 * about latest values take it as well. 92 * 93 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock, 94 * dq_list_lock > dq_state_lock 95 * 96 * Note that some things (eg. sb pointer, type, id) doesn't change during 97 * the life of the dquot structure and so needn't to be protected by a lock 98 * 99 * Operation accessing dquots via inode pointers are protected by dquot_srcu. 100 * Operation of reading pointer needs srcu_read_lock(&dquot_srcu), and 101 * synchronize_srcu(&dquot_srcu) is called after clearing pointers from 102 * inode and before dropping dquot references to avoid use of dquots after 103 * they are freed. dq_data_lock is used to serialize the pointer setting and 104 * clearing operations. 105 * Special care needs to be taken about S_NOQUOTA inode flag (marking that 106 * inode is a quota file). Functions adding pointers from inode to dquots have 107 * to check this flag under dq_data_lock and then (if S_NOQUOTA is not set) they 108 * have to do all pointer modifications before dropping dq_data_lock. This makes 109 * sure they cannot race with quotaon which first sets S_NOQUOTA flag and 110 * then drops all pointers to dquots from an inode. 111 * 112 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced 113 * from inodes (dquot_alloc_space() and such don't check the dq_lock). 114 * Currently dquot is locked only when it is being read to memory (or space for 115 * it is being allocated) on the first dqget() and when it is being released on 116 * the last dqput(). The allocation and release oparations are serialized by 117 * the dq_lock and by checking the use count in dquot_release(). Write 118 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock 119 * spinlock to internal buffers before writing. 120 * 121 * Lock ordering (including related VFS locks) is the following: 122 * dqonoff_mutex > i_mutex > journal_lock > dquot->dq_lock > dqio_mutex 123 * dqonoff_mutex > i_mutex comes from dquot_quota_sync, dquot_enable, etc. 124 */ 125 126 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_list_lock); 127 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock); 128 __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock); 129 EXPORT_SYMBOL(dq_data_lock); 130 DEFINE_STATIC_SRCU(dquot_srcu); 131 132 void __quota_error(struct super_block *sb, const char *func, 133 const char *fmt, ...) 134 { 135 if (printk_ratelimit()) { 136 va_list args; 137 struct va_format vaf; 138 139 va_start(args, fmt); 140 141 vaf.fmt = fmt; 142 vaf.va = &args; 143 144 printk(KERN_ERR "Quota error (device %s): %s: %pV\n", 145 sb->s_id, func, &vaf); 146 147 va_end(args); 148 } 149 } 150 EXPORT_SYMBOL(__quota_error); 151 152 #if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING) 153 static char *quotatypes[] = INITQFNAMES; 154 #endif 155 static struct quota_format_type *quota_formats; /* List of registered formats */ 156 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 157 158 /* SLAB cache for dquot structures */ 159 static struct kmem_cache *dquot_cachep; 160 161 int register_quota_format(struct quota_format_type *fmt) 162 { 163 spin_lock(&dq_list_lock); 164 fmt->qf_next = quota_formats; 165 quota_formats = fmt; 166 spin_unlock(&dq_list_lock); 167 return 0; 168 } 169 EXPORT_SYMBOL(register_quota_format); 170 171 void unregister_quota_format(struct quota_format_type *fmt) 172 { 173 struct quota_format_type **actqf; 174 175 spin_lock(&dq_list_lock); 176 for (actqf = "a_formats; *actqf && *actqf != fmt; 177 actqf = &(*actqf)->qf_next) 178 ; 179 if (*actqf) 180 *actqf = (*actqf)->qf_next; 181 spin_unlock(&dq_list_lock); 182 } 183 EXPORT_SYMBOL(unregister_quota_format); 184 185 static struct quota_format_type *find_quota_format(int id) 186 { 187 struct quota_format_type *actqf; 188 189 spin_lock(&dq_list_lock); 190 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 191 actqf = actqf->qf_next) 192 ; 193 if (!actqf || !try_module_get(actqf->qf_owner)) { 194 int qm; 195 196 spin_unlock(&dq_list_lock); 197 198 for (qm = 0; module_names[qm].qm_fmt_id && 199 module_names[qm].qm_fmt_id != id; qm++) 200 ; 201 if (!module_names[qm].qm_fmt_id || 202 request_module(module_names[qm].qm_mod_name)) 203 return NULL; 204 205 spin_lock(&dq_list_lock); 206 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; 207 actqf = actqf->qf_next) 208 ; 209 if (actqf && !try_module_get(actqf->qf_owner)) 210 actqf = NULL; 211 } 212 spin_unlock(&dq_list_lock); 213 return actqf; 214 } 215 216 static void put_quota_format(struct quota_format_type *fmt) 217 { 218 module_put(fmt->qf_owner); 219 } 220 221 /* 222 * Dquot List Management: 223 * The quota code uses three lists for dquot management: the inuse_list, 224 * free_dquots, and dquot_hash[] array. A single dquot structure may be 225 * on all three lists, depending on its current state. 226 * 227 * All dquots are placed to the end of inuse_list when first created, and this 228 * list is used for invalidate operation, which must look at every dquot. 229 * 230 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 231 * and this list is searched whenever we need an available dquot. Dquots are 232 * removed from the list as soon as they are used again, and 233 * dqstats.free_dquots gives the number of dquots on the list. When 234 * dquot is invalidated it's completely released from memory. 235 * 236 * Dquots with a specific identity (device, type and id) are placed on 237 * one of the dquot_hash[] hash chains. The provides an efficient search 238 * mechanism to locate a specific dquot. 239 */ 240 241 static LIST_HEAD(inuse_list); 242 static LIST_HEAD(free_dquots); 243 static unsigned int dq_hash_bits, dq_hash_mask; 244 static struct hlist_head *dquot_hash; 245 246 struct dqstats dqstats; 247 EXPORT_SYMBOL(dqstats); 248 249 static qsize_t inode_get_rsv_space(struct inode *inode); 250 static void __dquot_initialize(struct inode *inode, int type); 251 252 static inline unsigned int 253 hashfn(const struct super_block *sb, struct kqid qid) 254 { 255 unsigned int id = from_kqid(&init_user_ns, qid); 256 int type = qid.type; 257 unsigned long tmp; 258 259 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 260 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 261 } 262 263 /* 264 * Following list functions expect dq_list_lock to be held 265 */ 266 static inline void insert_dquot_hash(struct dquot *dquot) 267 { 268 struct hlist_head *head; 269 head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id); 270 hlist_add_head(&dquot->dq_hash, head); 271 } 272 273 static inline void remove_dquot_hash(struct dquot *dquot) 274 { 275 hlist_del_init(&dquot->dq_hash); 276 } 277 278 static struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, 279 struct kqid qid) 280 { 281 struct hlist_node *node; 282 struct dquot *dquot; 283 284 hlist_for_each (node, dquot_hash+hashent) { 285 dquot = hlist_entry(node, struct dquot, dq_hash); 286 if (dquot->dq_sb == sb && qid_eq(dquot->dq_id, qid)) 287 return dquot; 288 } 289 return NULL; 290 } 291 292 /* Add a dquot to the tail of the free list */ 293 static inline void put_dquot_last(struct dquot *dquot) 294 { 295 list_add_tail(&dquot->dq_free, &free_dquots); 296 dqstats_inc(DQST_FREE_DQUOTS); 297 } 298 299 static inline void remove_free_dquot(struct dquot *dquot) 300 { 301 if (list_empty(&dquot->dq_free)) 302 return; 303 list_del_init(&dquot->dq_free); 304 dqstats_dec(DQST_FREE_DQUOTS); 305 } 306 307 static inline void put_inuse(struct dquot *dquot) 308 { 309 /* We add to the back of inuse list so we don't have to restart 310 * when traversing this list and we block */ 311 list_add_tail(&dquot->dq_inuse, &inuse_list); 312 dqstats_inc(DQST_ALLOC_DQUOTS); 313 } 314 315 static inline void remove_inuse(struct dquot *dquot) 316 { 317 dqstats_dec(DQST_ALLOC_DQUOTS); 318 list_del(&dquot->dq_inuse); 319 } 320 /* 321 * End of list functions needing dq_list_lock 322 */ 323 324 static void wait_on_dquot(struct dquot *dquot) 325 { 326 mutex_lock(&dquot->dq_lock); 327 mutex_unlock(&dquot->dq_lock); 328 } 329 330 static inline int dquot_dirty(struct dquot *dquot) 331 { 332 return test_bit(DQ_MOD_B, &dquot->dq_flags); 333 } 334 335 static inline int mark_dquot_dirty(struct dquot *dquot) 336 { 337 return dquot->dq_sb->dq_op->mark_dirty(dquot); 338 } 339 340 /* Mark dquot dirty in atomic manner, and return it's old dirty flag state */ 341 int dquot_mark_dquot_dirty(struct dquot *dquot) 342 { 343 int ret = 1; 344 345 /* If quota is dirty already, we don't have to acquire dq_list_lock */ 346 if (test_bit(DQ_MOD_B, &dquot->dq_flags)) 347 return 1; 348 349 spin_lock(&dq_list_lock); 350 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) { 351 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 352 info[dquot->dq_id.type].dqi_dirty_list); 353 ret = 0; 354 } 355 spin_unlock(&dq_list_lock); 356 return ret; 357 } 358 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 359 360 /* Dirtify all the dquots - this can block when journalling */ 361 static inline int mark_all_dquot_dirty(struct dquot * const *dquot) 362 { 363 int ret, err, cnt; 364 365 ret = err = 0; 366 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 367 if (dquot[cnt]) 368 /* Even in case of error we have to continue */ 369 ret = mark_dquot_dirty(dquot[cnt]); 370 if (!err) 371 err = ret; 372 } 373 return err; 374 } 375 376 static inline void dqput_all(struct dquot **dquot) 377 { 378 unsigned int cnt; 379 380 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 381 dqput(dquot[cnt]); 382 } 383 384 /* This function needs dq_list_lock */ 385 static inline int clear_dquot_dirty(struct dquot *dquot) 386 { 387 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 388 return 0; 389 list_del_init(&dquot->dq_dirty); 390 return 1; 391 } 392 393 void mark_info_dirty(struct super_block *sb, int type) 394 { 395 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 396 } 397 EXPORT_SYMBOL(mark_info_dirty); 398 399 /* 400 * Read dquot from disk and alloc space for it 401 */ 402 403 int dquot_acquire(struct dquot *dquot) 404 { 405 int ret = 0, ret2 = 0; 406 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 407 408 mutex_lock(&dquot->dq_lock); 409 mutex_lock(&dqopt->dqio_mutex); 410 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 411 ret = dqopt->ops[dquot->dq_id.type]->read_dqblk(dquot); 412 if (ret < 0) 413 goto out_iolock; 414 set_bit(DQ_READ_B, &dquot->dq_flags); 415 /* Instantiate dquot if needed */ 416 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 417 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 418 /* Write the info if needed */ 419 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 420 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 421 dquot->dq_sb, dquot->dq_id.type); 422 } 423 if (ret < 0) 424 goto out_iolock; 425 if (ret2 < 0) { 426 ret = ret2; 427 goto out_iolock; 428 } 429 } 430 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 431 out_iolock: 432 mutex_unlock(&dqopt->dqio_mutex); 433 mutex_unlock(&dquot->dq_lock); 434 return ret; 435 } 436 EXPORT_SYMBOL(dquot_acquire); 437 438 /* 439 * Write dquot to disk 440 */ 441 int dquot_commit(struct dquot *dquot) 442 { 443 int ret = 0; 444 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 445 446 mutex_lock(&dqopt->dqio_mutex); 447 spin_lock(&dq_list_lock); 448 if (!clear_dquot_dirty(dquot)) { 449 spin_unlock(&dq_list_lock); 450 goto out_sem; 451 } 452 spin_unlock(&dq_list_lock); 453 /* Inactive dquot can be only if there was error during read/init 454 * => we have better not writing it */ 455 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 456 ret = dqopt->ops[dquot->dq_id.type]->commit_dqblk(dquot); 457 else 458 ret = -EIO; 459 out_sem: 460 mutex_unlock(&dqopt->dqio_mutex); 461 return ret; 462 } 463 EXPORT_SYMBOL(dquot_commit); 464 465 /* 466 * Release dquot 467 */ 468 int dquot_release(struct dquot *dquot) 469 { 470 int ret = 0, ret2 = 0; 471 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 472 473 mutex_lock(&dquot->dq_lock); 474 /* Check whether we are not racing with some other dqget() */ 475 if (atomic_read(&dquot->dq_count) > 1) 476 goto out_dqlock; 477 mutex_lock(&dqopt->dqio_mutex); 478 if (dqopt->ops[dquot->dq_id.type]->release_dqblk) { 479 ret = dqopt->ops[dquot->dq_id.type]->release_dqblk(dquot); 480 /* Write the info */ 481 if (info_dirty(&dqopt->info[dquot->dq_id.type])) { 482 ret2 = dqopt->ops[dquot->dq_id.type]->write_file_info( 483 dquot->dq_sb, dquot->dq_id.type); 484 } 485 if (ret >= 0) 486 ret = ret2; 487 } 488 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 489 mutex_unlock(&dqopt->dqio_mutex); 490 out_dqlock: 491 mutex_unlock(&dquot->dq_lock); 492 return ret; 493 } 494 EXPORT_SYMBOL(dquot_release); 495 496 void dquot_destroy(struct dquot *dquot) 497 { 498 kmem_cache_free(dquot_cachep, dquot); 499 } 500 EXPORT_SYMBOL(dquot_destroy); 501 502 static inline void do_destroy_dquot(struct dquot *dquot) 503 { 504 dquot->dq_sb->dq_op->destroy_dquot(dquot); 505 } 506 507 /* Invalidate all dquots on the list. Note that this function is called after 508 * quota is disabled and pointers from inodes removed so there cannot be new 509 * quota users. There can still be some users of quotas due to inodes being 510 * just deleted or pruned by prune_icache() (those are not attached to any 511 * list) or parallel quotactl call. We have to wait for such users. 512 */ 513 static void invalidate_dquots(struct super_block *sb, int type) 514 { 515 struct dquot *dquot, *tmp; 516 517 restart: 518 spin_lock(&dq_list_lock); 519 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 520 if (dquot->dq_sb != sb) 521 continue; 522 if (dquot->dq_id.type != type) 523 continue; 524 /* Wait for dquot users */ 525 if (atomic_read(&dquot->dq_count)) { 526 DEFINE_WAIT(wait); 527 528 dqgrab(dquot); 529 prepare_to_wait(&dquot->dq_wait_unused, &wait, 530 TASK_UNINTERRUPTIBLE); 531 spin_unlock(&dq_list_lock); 532 /* Once dqput() wakes us up, we know it's time to free 533 * the dquot. 534 * IMPORTANT: we rely on the fact that there is always 535 * at most one process waiting for dquot to free. 536 * Otherwise dq_count would be > 1 and we would never 537 * wake up. 538 */ 539 if (atomic_read(&dquot->dq_count) > 1) 540 schedule(); 541 finish_wait(&dquot->dq_wait_unused, &wait); 542 dqput(dquot); 543 /* At this moment dquot() need not exist (it could be 544 * reclaimed by prune_dqcache(). Hence we must 545 * restart. */ 546 goto restart; 547 } 548 /* 549 * Quota now has no users and it has been written on last 550 * dqput() 551 */ 552 remove_dquot_hash(dquot); 553 remove_free_dquot(dquot); 554 remove_inuse(dquot); 555 do_destroy_dquot(dquot); 556 } 557 spin_unlock(&dq_list_lock); 558 } 559 560 /* Call callback for every active dquot on given filesystem */ 561 int dquot_scan_active(struct super_block *sb, 562 int (*fn)(struct dquot *dquot, unsigned long priv), 563 unsigned long priv) 564 { 565 struct dquot *dquot, *old_dquot = NULL; 566 int ret = 0; 567 568 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 569 spin_lock(&dq_list_lock); 570 list_for_each_entry(dquot, &inuse_list, dq_inuse) { 571 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) 572 continue; 573 if (dquot->dq_sb != sb) 574 continue; 575 /* Now we have active dquot so we can just increase use count */ 576 atomic_inc(&dquot->dq_count); 577 spin_unlock(&dq_list_lock); 578 dqstats_inc(DQST_LOOKUPS); 579 dqput(old_dquot); 580 old_dquot = dquot; 581 /* 582 * ->release_dquot() can be racing with us. Our reference 583 * protects us from new calls to it so just wait for any 584 * outstanding call and recheck the DQ_ACTIVE_B after that. 585 */ 586 wait_on_dquot(dquot); 587 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 588 ret = fn(dquot, priv); 589 if (ret < 0) 590 goto out; 591 } 592 spin_lock(&dq_list_lock); 593 /* We are safe to continue now because our dquot could not 594 * be moved out of the inuse list while we hold the reference */ 595 } 596 spin_unlock(&dq_list_lock); 597 out: 598 dqput(old_dquot); 599 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 600 return ret; 601 } 602 EXPORT_SYMBOL(dquot_scan_active); 603 604 /* Write all dquot structures to quota files */ 605 int dquot_writeback_dquots(struct super_block *sb, int type) 606 { 607 struct list_head *dirty; 608 struct dquot *dquot; 609 struct quota_info *dqopt = sb_dqopt(sb); 610 int cnt; 611 int err, ret = 0; 612 613 mutex_lock(&dqopt->dqonoff_mutex); 614 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 615 if (type != -1 && cnt != type) 616 continue; 617 if (!sb_has_quota_active(sb, cnt)) 618 continue; 619 spin_lock(&dq_list_lock); 620 dirty = &dqopt->info[cnt].dqi_dirty_list; 621 while (!list_empty(dirty)) { 622 dquot = list_first_entry(dirty, struct dquot, 623 dq_dirty); 624 /* Dirty and inactive can be only bad dquot... */ 625 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 626 clear_dquot_dirty(dquot); 627 continue; 628 } 629 /* Now we have active dquot from which someone is 630 * holding reference so we can safely just increase 631 * use count */ 632 dqgrab(dquot); 633 spin_unlock(&dq_list_lock); 634 dqstats_inc(DQST_LOOKUPS); 635 err = sb->dq_op->write_dquot(dquot); 636 if (!ret && err) 637 ret = err; 638 dqput(dquot); 639 spin_lock(&dq_list_lock); 640 } 641 spin_unlock(&dq_list_lock); 642 } 643 644 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 645 if ((cnt == type || type == -1) && sb_has_quota_active(sb, cnt) 646 && info_dirty(&dqopt->info[cnt])) 647 sb->dq_op->write_info(sb, cnt); 648 dqstats_inc(DQST_SYNCS); 649 mutex_unlock(&dqopt->dqonoff_mutex); 650 651 return ret; 652 } 653 EXPORT_SYMBOL(dquot_writeback_dquots); 654 655 /* Write all dquot structures to disk and make them visible from userspace */ 656 int dquot_quota_sync(struct super_block *sb, int type) 657 { 658 struct quota_info *dqopt = sb_dqopt(sb); 659 int cnt; 660 int ret; 661 662 ret = dquot_writeback_dquots(sb, type); 663 if (ret) 664 return ret; 665 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 666 return 0; 667 668 /* This is not very clever (and fast) but currently I don't know about 669 * any other simple way of getting quota data to disk and we must get 670 * them there for userspace to be visible... */ 671 if (sb->s_op->sync_fs) 672 sb->s_op->sync_fs(sb, 1); 673 sync_blockdev(sb->s_bdev); 674 675 /* 676 * Now when everything is written we can discard the pagecache so 677 * that userspace sees the changes. 678 */ 679 mutex_lock(&dqopt->dqonoff_mutex); 680 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 681 if (type != -1 && cnt != type) 682 continue; 683 if (!sb_has_quota_active(sb, cnt)) 684 continue; 685 mutex_lock(&dqopt->files[cnt]->i_mutex); 686 truncate_inode_pages(&dqopt->files[cnt]->i_data, 0); 687 mutex_unlock(&dqopt->files[cnt]->i_mutex); 688 } 689 mutex_unlock(&dqopt->dqonoff_mutex); 690 691 return 0; 692 } 693 EXPORT_SYMBOL(dquot_quota_sync); 694 695 static unsigned long 696 dqcache_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 697 { 698 struct list_head *head; 699 struct dquot *dquot; 700 unsigned long freed = 0; 701 702 spin_lock(&dq_list_lock); 703 head = free_dquots.prev; 704 while (head != &free_dquots && sc->nr_to_scan) { 705 dquot = list_entry(head, struct dquot, dq_free); 706 remove_dquot_hash(dquot); 707 remove_free_dquot(dquot); 708 remove_inuse(dquot); 709 do_destroy_dquot(dquot); 710 sc->nr_to_scan--; 711 freed++; 712 head = free_dquots.prev; 713 } 714 spin_unlock(&dq_list_lock); 715 return freed; 716 } 717 718 static unsigned long 719 dqcache_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 720 { 721 return vfs_pressure_ratio( 722 percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])); 723 } 724 725 static struct shrinker dqcache_shrinker = { 726 .count_objects = dqcache_shrink_count, 727 .scan_objects = dqcache_shrink_scan, 728 .seeks = DEFAULT_SEEKS, 729 }; 730 731 /* 732 * Put reference to dquot 733 */ 734 void dqput(struct dquot *dquot) 735 { 736 int ret; 737 738 if (!dquot) 739 return; 740 #ifdef CONFIG_QUOTA_DEBUG 741 if (!atomic_read(&dquot->dq_count)) { 742 quota_error(dquot->dq_sb, "trying to free free dquot of %s %d", 743 quotatypes[dquot->dq_id.type], 744 from_kqid(&init_user_ns, dquot->dq_id)); 745 BUG(); 746 } 747 #endif 748 dqstats_inc(DQST_DROPS); 749 we_slept: 750 spin_lock(&dq_list_lock); 751 if (atomic_read(&dquot->dq_count) > 1) { 752 /* We have more than one user... nothing to do */ 753 atomic_dec(&dquot->dq_count); 754 /* Releasing dquot during quotaoff phase? */ 755 if (!sb_has_quota_active(dquot->dq_sb, dquot->dq_id.type) && 756 atomic_read(&dquot->dq_count) == 1) 757 wake_up(&dquot->dq_wait_unused); 758 spin_unlock(&dq_list_lock); 759 return; 760 } 761 /* Need to release dquot? */ 762 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 763 spin_unlock(&dq_list_lock); 764 /* Commit dquot before releasing */ 765 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 766 if (ret < 0) { 767 quota_error(dquot->dq_sb, "Can't write quota structure" 768 " (error %d). Quota may get out of sync!", 769 ret); 770 /* 771 * We clear dirty bit anyway, so that we avoid 772 * infinite loop here 773 */ 774 spin_lock(&dq_list_lock); 775 clear_dquot_dirty(dquot); 776 spin_unlock(&dq_list_lock); 777 } 778 goto we_slept; 779 } 780 /* Clear flag in case dquot was inactive (something bad happened) */ 781 clear_dquot_dirty(dquot); 782 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 783 spin_unlock(&dq_list_lock); 784 dquot->dq_sb->dq_op->release_dquot(dquot); 785 goto we_slept; 786 } 787 atomic_dec(&dquot->dq_count); 788 #ifdef CONFIG_QUOTA_DEBUG 789 /* sanity check */ 790 BUG_ON(!list_empty(&dquot->dq_free)); 791 #endif 792 put_dquot_last(dquot); 793 spin_unlock(&dq_list_lock); 794 } 795 EXPORT_SYMBOL(dqput); 796 797 struct dquot *dquot_alloc(struct super_block *sb, int type) 798 { 799 return kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 800 } 801 EXPORT_SYMBOL(dquot_alloc); 802 803 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 804 { 805 struct dquot *dquot; 806 807 dquot = sb->dq_op->alloc_dquot(sb, type); 808 if(!dquot) 809 return NULL; 810 811 mutex_init(&dquot->dq_lock); 812 INIT_LIST_HEAD(&dquot->dq_free); 813 INIT_LIST_HEAD(&dquot->dq_inuse); 814 INIT_HLIST_NODE(&dquot->dq_hash); 815 INIT_LIST_HEAD(&dquot->dq_dirty); 816 init_waitqueue_head(&dquot->dq_wait_unused); 817 dquot->dq_sb = sb; 818 dquot->dq_id = make_kqid_invalid(type); 819 atomic_set(&dquot->dq_count, 1); 820 821 return dquot; 822 } 823 824 /* 825 * Get reference to dquot 826 * 827 * Locking is slightly tricky here. We are guarded from parallel quotaoff() 828 * destroying our dquot by: 829 * a) checking for quota flags under dq_list_lock and 830 * b) getting a reference to dquot before we release dq_list_lock 831 */ 832 struct dquot *dqget(struct super_block *sb, struct kqid qid) 833 { 834 unsigned int hashent = hashfn(sb, qid); 835 struct dquot *dquot = NULL, *empty = NULL; 836 837 if (!sb_has_quota_active(sb, qid.type)) 838 return NULL; 839 we_slept: 840 spin_lock(&dq_list_lock); 841 spin_lock(&dq_state_lock); 842 if (!sb_has_quota_active(sb, qid.type)) { 843 spin_unlock(&dq_state_lock); 844 spin_unlock(&dq_list_lock); 845 goto out; 846 } 847 spin_unlock(&dq_state_lock); 848 849 dquot = find_dquot(hashent, sb, qid); 850 if (!dquot) { 851 if (!empty) { 852 spin_unlock(&dq_list_lock); 853 empty = get_empty_dquot(sb, qid.type); 854 if (!empty) 855 schedule(); /* Try to wait for a moment... */ 856 goto we_slept; 857 } 858 dquot = empty; 859 empty = NULL; 860 dquot->dq_id = qid; 861 /* all dquots go on the inuse_list */ 862 put_inuse(dquot); 863 /* hash it first so it can be found */ 864 insert_dquot_hash(dquot); 865 spin_unlock(&dq_list_lock); 866 dqstats_inc(DQST_LOOKUPS); 867 } else { 868 if (!atomic_read(&dquot->dq_count)) 869 remove_free_dquot(dquot); 870 atomic_inc(&dquot->dq_count); 871 spin_unlock(&dq_list_lock); 872 dqstats_inc(DQST_CACHE_HITS); 873 dqstats_inc(DQST_LOOKUPS); 874 } 875 /* Wait for dq_lock - after this we know that either dquot_release() is 876 * already finished or it will be canceled due to dq_count > 1 test */ 877 wait_on_dquot(dquot); 878 /* Read the dquot / allocate space in quota file */ 879 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && 880 sb->dq_op->acquire_dquot(dquot) < 0) { 881 dqput(dquot); 882 dquot = NULL; 883 goto out; 884 } 885 #ifdef CONFIG_QUOTA_DEBUG 886 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 887 #endif 888 out: 889 if (empty) 890 do_destroy_dquot(empty); 891 892 return dquot; 893 } 894 EXPORT_SYMBOL(dqget); 895 896 static inline struct dquot **i_dquot(struct inode *inode) 897 { 898 return inode->i_sb->s_op->get_dquots(inode); 899 } 900 901 static int dqinit_needed(struct inode *inode, int type) 902 { 903 struct dquot * const *dquots; 904 int cnt; 905 906 if (IS_NOQUOTA(inode)) 907 return 0; 908 909 dquots = i_dquot(inode); 910 if (type != -1) 911 return !dquots[type]; 912 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 913 if (!dquots[cnt]) 914 return 1; 915 return 0; 916 } 917 918 /* This routine is guarded by dqonoff_mutex mutex */ 919 static void add_dquot_ref(struct super_block *sb, int type) 920 { 921 struct inode *inode, *old_inode = NULL; 922 #ifdef CONFIG_QUOTA_DEBUG 923 int reserved = 0; 924 #endif 925 926 spin_lock(&inode_sb_list_lock); 927 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 928 spin_lock(&inode->i_lock); 929 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || 930 !atomic_read(&inode->i_writecount) || 931 !dqinit_needed(inode, type)) { 932 spin_unlock(&inode->i_lock); 933 continue; 934 } 935 __iget(inode); 936 spin_unlock(&inode->i_lock); 937 spin_unlock(&inode_sb_list_lock); 938 939 #ifdef CONFIG_QUOTA_DEBUG 940 if (unlikely(inode_get_rsv_space(inode) > 0)) 941 reserved = 1; 942 #endif 943 iput(old_inode); 944 __dquot_initialize(inode, type); 945 946 /* 947 * We hold a reference to 'inode' so it couldn't have been 948 * removed from s_inodes list while we dropped the 949 * inode_sb_list_lock We cannot iput the inode now as we can be 950 * holding the last reference and we cannot iput it under 951 * inode_sb_list_lock. So we keep the reference and iput it 952 * later. 953 */ 954 old_inode = inode; 955 spin_lock(&inode_sb_list_lock); 956 } 957 spin_unlock(&inode_sb_list_lock); 958 iput(old_inode); 959 960 #ifdef CONFIG_QUOTA_DEBUG 961 if (reserved) { 962 quota_error(sb, "Writes happened before quota was turned on " 963 "thus quota information is probably inconsistent. " 964 "Please run quotacheck(8)"); 965 } 966 #endif 967 } 968 969 /* 970 * Remove references to dquots from inode and add dquot to list for freeing 971 * if we have the last reference to dquot 972 */ 973 static void remove_inode_dquot_ref(struct inode *inode, int type, 974 struct list_head *tofree_head) 975 { 976 struct dquot **dquots = i_dquot(inode); 977 struct dquot *dquot = dquots[type]; 978 979 if (!dquot) 980 return; 981 982 dquots[type] = NULL; 983 if (list_empty(&dquot->dq_free)) { 984 /* 985 * The inode still has reference to dquot so it can't be in the 986 * free list 987 */ 988 spin_lock(&dq_list_lock); 989 list_add(&dquot->dq_free, tofree_head); 990 spin_unlock(&dq_list_lock); 991 } else { 992 /* 993 * Dquot is already in a list to put so we won't drop the last 994 * reference here. 995 */ 996 dqput(dquot); 997 } 998 } 999 1000 /* 1001 * Free list of dquots 1002 * Dquots are removed from inodes and no new references can be got so we are 1003 * the only ones holding reference 1004 */ 1005 static void put_dquot_list(struct list_head *tofree_head) 1006 { 1007 struct list_head *act_head; 1008 struct dquot *dquot; 1009 1010 act_head = tofree_head->next; 1011 while (act_head != tofree_head) { 1012 dquot = list_entry(act_head, struct dquot, dq_free); 1013 act_head = act_head->next; 1014 /* Remove dquot from the list so we won't have problems... */ 1015 list_del_init(&dquot->dq_free); 1016 dqput(dquot); 1017 } 1018 } 1019 1020 static void remove_dquot_ref(struct super_block *sb, int type, 1021 struct list_head *tofree_head) 1022 { 1023 struct inode *inode; 1024 int reserved = 0; 1025 1026 spin_lock(&inode_sb_list_lock); 1027 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 1028 /* 1029 * We have to scan also I_NEW inodes because they can already 1030 * have quota pointer initialized. Luckily, we need to touch 1031 * only quota pointers and these have separate locking 1032 * (dq_data_lock). 1033 */ 1034 spin_lock(&dq_data_lock); 1035 if (!IS_NOQUOTA(inode)) { 1036 if (unlikely(inode_get_rsv_space(inode) > 0)) 1037 reserved = 1; 1038 remove_inode_dquot_ref(inode, type, tofree_head); 1039 } 1040 spin_unlock(&dq_data_lock); 1041 } 1042 spin_unlock(&inode_sb_list_lock); 1043 #ifdef CONFIG_QUOTA_DEBUG 1044 if (reserved) { 1045 printk(KERN_WARNING "VFS (%s): Writes happened after quota" 1046 " was disabled thus quota information is probably " 1047 "inconsistent. Please run quotacheck(8).\n", sb->s_id); 1048 } 1049 #endif 1050 } 1051 1052 /* Gather all references from inodes and drop them */ 1053 static void drop_dquot_ref(struct super_block *sb, int type) 1054 { 1055 LIST_HEAD(tofree_head); 1056 1057 if (sb->dq_op) { 1058 remove_dquot_ref(sb, type, &tofree_head); 1059 synchronize_srcu(&dquot_srcu); 1060 put_dquot_list(&tofree_head); 1061 } 1062 } 1063 1064 static inline void dquot_incr_inodes(struct dquot *dquot, qsize_t number) 1065 { 1066 dquot->dq_dqb.dqb_curinodes += number; 1067 } 1068 1069 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 1070 { 1071 dquot->dq_dqb.dqb_curspace += number; 1072 } 1073 1074 static inline void dquot_resv_space(struct dquot *dquot, qsize_t number) 1075 { 1076 dquot->dq_dqb.dqb_rsvspace += number; 1077 } 1078 1079 /* 1080 * Claim reserved quota space 1081 */ 1082 static void dquot_claim_reserved_space(struct dquot *dquot, qsize_t number) 1083 { 1084 if (dquot->dq_dqb.dqb_rsvspace < number) { 1085 WARN_ON_ONCE(1); 1086 number = dquot->dq_dqb.dqb_rsvspace; 1087 } 1088 dquot->dq_dqb.dqb_curspace += number; 1089 dquot->dq_dqb.dqb_rsvspace -= number; 1090 } 1091 1092 static void dquot_reclaim_reserved_space(struct dquot *dquot, qsize_t number) 1093 { 1094 if (WARN_ON_ONCE(dquot->dq_dqb.dqb_curspace < number)) 1095 number = dquot->dq_dqb.dqb_curspace; 1096 dquot->dq_dqb.dqb_rsvspace += number; 1097 dquot->dq_dqb.dqb_curspace -= number; 1098 } 1099 1100 static inline 1101 void dquot_free_reserved_space(struct dquot *dquot, qsize_t number) 1102 { 1103 if (dquot->dq_dqb.dqb_rsvspace >= number) 1104 dquot->dq_dqb.dqb_rsvspace -= number; 1105 else { 1106 WARN_ON_ONCE(1); 1107 dquot->dq_dqb.dqb_rsvspace = 0; 1108 } 1109 } 1110 1111 static void dquot_decr_inodes(struct dquot *dquot, qsize_t number) 1112 { 1113 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1114 dquot->dq_dqb.dqb_curinodes >= number) 1115 dquot->dq_dqb.dqb_curinodes -= number; 1116 else 1117 dquot->dq_dqb.dqb_curinodes = 0; 1118 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1119 dquot->dq_dqb.dqb_itime = (time_t) 0; 1120 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1121 } 1122 1123 static void dquot_decr_space(struct dquot *dquot, qsize_t number) 1124 { 1125 if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE || 1126 dquot->dq_dqb.dqb_curspace >= number) 1127 dquot->dq_dqb.dqb_curspace -= number; 1128 else 1129 dquot->dq_dqb.dqb_curspace = 0; 1130 if (dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1131 dquot->dq_dqb.dqb_btime = (time_t) 0; 1132 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1133 } 1134 1135 struct dquot_warn { 1136 struct super_block *w_sb; 1137 struct kqid w_dq_id; 1138 short w_type; 1139 }; 1140 1141 static int warning_issued(struct dquot *dquot, const int warntype) 1142 { 1143 int flag = (warntype == QUOTA_NL_BHARDWARN || 1144 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 1145 ((warntype == QUOTA_NL_IHARDWARN || 1146 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 1147 1148 if (!flag) 1149 return 0; 1150 return test_and_set_bit(flag, &dquot->dq_flags); 1151 } 1152 1153 #ifdef CONFIG_PRINT_QUOTA_WARNING 1154 static int flag_print_warnings = 1; 1155 1156 static int need_print_warning(struct dquot_warn *warn) 1157 { 1158 if (!flag_print_warnings) 1159 return 0; 1160 1161 switch (warn->w_dq_id.type) { 1162 case USRQUOTA: 1163 return uid_eq(current_fsuid(), warn->w_dq_id.uid); 1164 case GRPQUOTA: 1165 return in_group_p(warn->w_dq_id.gid); 1166 case PRJQUOTA: /* Never taken... Just make gcc happy */ 1167 return 0; 1168 } 1169 return 0; 1170 } 1171 1172 /* Print warning to user which exceeded quota */ 1173 static void print_warning(struct dquot_warn *warn) 1174 { 1175 char *msg = NULL; 1176 struct tty_struct *tty; 1177 int warntype = warn->w_type; 1178 1179 if (warntype == QUOTA_NL_IHARDBELOW || 1180 warntype == QUOTA_NL_ISOFTBELOW || 1181 warntype == QUOTA_NL_BHARDBELOW || 1182 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(warn)) 1183 return; 1184 1185 tty = get_current_tty(); 1186 if (!tty) 1187 return; 1188 tty_write_message(tty, warn->w_sb->s_id); 1189 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 1190 tty_write_message(tty, ": warning, "); 1191 else 1192 tty_write_message(tty, ": write failed, "); 1193 tty_write_message(tty, quotatypes[warn->w_dq_id.type]); 1194 switch (warntype) { 1195 case QUOTA_NL_IHARDWARN: 1196 msg = " file limit reached.\r\n"; 1197 break; 1198 case QUOTA_NL_ISOFTLONGWARN: 1199 msg = " file quota exceeded too long.\r\n"; 1200 break; 1201 case QUOTA_NL_ISOFTWARN: 1202 msg = " file quota exceeded.\r\n"; 1203 break; 1204 case QUOTA_NL_BHARDWARN: 1205 msg = " block limit reached.\r\n"; 1206 break; 1207 case QUOTA_NL_BSOFTLONGWARN: 1208 msg = " block quota exceeded too long.\r\n"; 1209 break; 1210 case QUOTA_NL_BSOFTWARN: 1211 msg = " block quota exceeded.\r\n"; 1212 break; 1213 } 1214 tty_write_message(tty, msg); 1215 tty_kref_put(tty); 1216 } 1217 #endif 1218 1219 static void prepare_warning(struct dquot_warn *warn, struct dquot *dquot, 1220 int warntype) 1221 { 1222 if (warning_issued(dquot, warntype)) 1223 return; 1224 warn->w_type = warntype; 1225 warn->w_sb = dquot->dq_sb; 1226 warn->w_dq_id = dquot->dq_id; 1227 } 1228 1229 /* 1230 * Write warnings to the console and send warning messages over netlink. 1231 * 1232 * Note that this function can call into tty and networking code. 1233 */ 1234 static void flush_warnings(struct dquot_warn *warn) 1235 { 1236 int i; 1237 1238 for (i = 0; i < MAXQUOTAS; i++) { 1239 if (warn[i].w_type == QUOTA_NL_NOWARN) 1240 continue; 1241 #ifdef CONFIG_PRINT_QUOTA_WARNING 1242 print_warning(&warn[i]); 1243 #endif 1244 quota_send_warning(warn[i].w_dq_id, 1245 warn[i].w_sb->s_dev, warn[i].w_type); 1246 } 1247 } 1248 1249 static int ignore_hardlimit(struct dquot *dquot) 1250 { 1251 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 1252 1253 return capable(CAP_SYS_RESOURCE) && 1254 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || 1255 !(info->dqi_flags & DQF_ROOT_SQUASH)); 1256 } 1257 1258 /* needs dq_data_lock */ 1259 static int check_idq(struct dquot *dquot, qsize_t inodes, 1260 struct dquot_warn *warn) 1261 { 1262 qsize_t newinodes = dquot->dq_dqb.dqb_curinodes + inodes; 1263 1264 if (!sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type) || 1265 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1266 return 0; 1267 1268 if (dquot->dq_dqb.dqb_ihardlimit && 1269 newinodes > dquot->dq_dqb.dqb_ihardlimit && 1270 !ignore_hardlimit(dquot)) { 1271 prepare_warning(warn, dquot, QUOTA_NL_IHARDWARN); 1272 return -EDQUOT; 1273 } 1274 1275 if (dquot->dq_dqb.dqb_isoftlimit && 1276 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1277 dquot->dq_dqb.dqb_itime && 1278 get_seconds() >= dquot->dq_dqb.dqb_itime && 1279 !ignore_hardlimit(dquot)) { 1280 prepare_warning(warn, dquot, QUOTA_NL_ISOFTLONGWARN); 1281 return -EDQUOT; 1282 } 1283 1284 if (dquot->dq_dqb.dqb_isoftlimit && 1285 newinodes > dquot->dq_dqb.dqb_isoftlimit && 1286 dquot->dq_dqb.dqb_itime == 0) { 1287 prepare_warning(warn, dquot, QUOTA_NL_ISOFTWARN); 1288 dquot->dq_dqb.dqb_itime = get_seconds() + 1289 sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type].dqi_igrace; 1290 } 1291 1292 return 0; 1293 } 1294 1295 /* needs dq_data_lock */ 1296 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, 1297 struct dquot_warn *warn) 1298 { 1299 qsize_t tspace; 1300 struct super_block *sb = dquot->dq_sb; 1301 1302 if (!sb_has_quota_limits_enabled(sb, dquot->dq_id.type) || 1303 test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1304 return 0; 1305 1306 tspace = dquot->dq_dqb.dqb_curspace + dquot->dq_dqb.dqb_rsvspace 1307 + space; 1308 1309 if (dquot->dq_dqb.dqb_bhardlimit && 1310 tspace > dquot->dq_dqb.dqb_bhardlimit && 1311 !ignore_hardlimit(dquot)) { 1312 if (!prealloc) 1313 prepare_warning(warn, dquot, QUOTA_NL_BHARDWARN); 1314 return -EDQUOT; 1315 } 1316 1317 if (dquot->dq_dqb.dqb_bsoftlimit && 1318 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1319 dquot->dq_dqb.dqb_btime && 1320 get_seconds() >= dquot->dq_dqb.dqb_btime && 1321 !ignore_hardlimit(dquot)) { 1322 if (!prealloc) 1323 prepare_warning(warn, dquot, QUOTA_NL_BSOFTLONGWARN); 1324 return -EDQUOT; 1325 } 1326 1327 if (dquot->dq_dqb.dqb_bsoftlimit && 1328 tspace > dquot->dq_dqb.dqb_bsoftlimit && 1329 dquot->dq_dqb.dqb_btime == 0) { 1330 if (!prealloc) { 1331 prepare_warning(warn, dquot, QUOTA_NL_BSOFTWARN); 1332 dquot->dq_dqb.dqb_btime = get_seconds() + 1333 sb_dqopt(sb)->info[dquot->dq_id.type].dqi_bgrace; 1334 } 1335 else 1336 /* 1337 * We don't allow preallocation to exceed softlimit so exceeding will 1338 * be always printed 1339 */ 1340 return -EDQUOT; 1341 } 1342 1343 return 0; 1344 } 1345 1346 static int info_idq_free(struct dquot *dquot, qsize_t inodes) 1347 { 1348 qsize_t newinodes; 1349 1350 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1351 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit || 1352 !sb_has_quota_limits_enabled(dquot->dq_sb, dquot->dq_id.type)) 1353 return QUOTA_NL_NOWARN; 1354 1355 newinodes = dquot->dq_dqb.dqb_curinodes - inodes; 1356 if (newinodes <= dquot->dq_dqb.dqb_isoftlimit) 1357 return QUOTA_NL_ISOFTBELOW; 1358 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1359 newinodes < dquot->dq_dqb.dqb_ihardlimit) 1360 return QUOTA_NL_IHARDBELOW; 1361 return QUOTA_NL_NOWARN; 1362 } 1363 1364 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1365 { 1366 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1367 dquot->dq_dqb.dqb_curspace <= dquot->dq_dqb.dqb_bsoftlimit) 1368 return QUOTA_NL_NOWARN; 1369 1370 if (dquot->dq_dqb.dqb_curspace - space <= dquot->dq_dqb.dqb_bsoftlimit) 1371 return QUOTA_NL_BSOFTBELOW; 1372 if (dquot->dq_dqb.dqb_curspace >= dquot->dq_dqb.dqb_bhardlimit && 1373 dquot->dq_dqb.dqb_curspace - space < dquot->dq_dqb.dqb_bhardlimit) 1374 return QUOTA_NL_BHARDBELOW; 1375 return QUOTA_NL_NOWARN; 1376 } 1377 1378 static int dquot_active(const struct inode *inode) 1379 { 1380 struct super_block *sb = inode->i_sb; 1381 1382 if (IS_NOQUOTA(inode)) 1383 return 0; 1384 return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb); 1385 } 1386 1387 /* 1388 * Initialize quota pointers in inode 1389 * 1390 * It is better to call this function outside of any transaction as it 1391 * might need a lot of space in journal for dquot structure allocation. 1392 */ 1393 static void __dquot_initialize(struct inode *inode, int type) 1394 { 1395 int cnt, init_needed = 0; 1396 struct dquot **dquots, *got[MAXQUOTAS]; 1397 struct super_block *sb = inode->i_sb; 1398 qsize_t rsv; 1399 1400 if (!dquot_active(inode)) 1401 return; 1402 1403 dquots = i_dquot(inode); 1404 1405 /* First get references to structures we might need. */ 1406 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1407 struct kqid qid; 1408 got[cnt] = NULL; 1409 if (type != -1 && cnt != type) 1410 continue; 1411 /* 1412 * The i_dquot should have been initialized in most cases, 1413 * we check it without locking here to avoid unnecessary 1414 * dqget()/dqput() calls. 1415 */ 1416 if (dquots[cnt]) 1417 continue; 1418 init_needed = 1; 1419 1420 switch (cnt) { 1421 case USRQUOTA: 1422 qid = make_kqid_uid(inode->i_uid); 1423 break; 1424 case GRPQUOTA: 1425 qid = make_kqid_gid(inode->i_gid); 1426 break; 1427 } 1428 got[cnt] = dqget(sb, qid); 1429 } 1430 1431 /* All required i_dquot has been initialized */ 1432 if (!init_needed) 1433 return; 1434 1435 spin_lock(&dq_data_lock); 1436 if (IS_NOQUOTA(inode)) 1437 goto out_err; 1438 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1439 if (type != -1 && cnt != type) 1440 continue; 1441 /* Avoid races with quotaoff() */ 1442 if (!sb_has_quota_active(sb, cnt)) 1443 continue; 1444 /* We could race with quotaon or dqget() could have failed */ 1445 if (!got[cnt]) 1446 continue; 1447 if (!dquots[cnt]) { 1448 dquots[cnt] = got[cnt]; 1449 got[cnt] = NULL; 1450 /* 1451 * Make quota reservation system happy if someone 1452 * did a write before quota was turned on 1453 */ 1454 rsv = inode_get_rsv_space(inode); 1455 if (unlikely(rsv)) 1456 dquot_resv_space(dquots[cnt], rsv); 1457 } 1458 } 1459 out_err: 1460 spin_unlock(&dq_data_lock); 1461 /* Drop unused references */ 1462 dqput_all(got); 1463 } 1464 1465 void dquot_initialize(struct inode *inode) 1466 { 1467 __dquot_initialize(inode, -1); 1468 } 1469 EXPORT_SYMBOL(dquot_initialize); 1470 1471 /* 1472 * Release all quotas referenced by inode. 1473 * 1474 * This function only be called on inode free or converting 1475 * a file to quota file, no other users for the i_dquot in 1476 * both cases, so we needn't call synchronize_srcu() after 1477 * clearing i_dquot. 1478 */ 1479 static void __dquot_drop(struct inode *inode) 1480 { 1481 int cnt; 1482 struct dquot **dquots = i_dquot(inode); 1483 struct dquot *put[MAXQUOTAS]; 1484 1485 spin_lock(&dq_data_lock); 1486 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1487 put[cnt] = dquots[cnt]; 1488 dquots[cnt] = NULL; 1489 } 1490 spin_unlock(&dq_data_lock); 1491 dqput_all(put); 1492 } 1493 1494 void dquot_drop(struct inode *inode) 1495 { 1496 struct dquot * const *dquots; 1497 int cnt; 1498 1499 if (IS_NOQUOTA(inode)) 1500 return; 1501 1502 /* 1503 * Test before calling to rule out calls from proc and such 1504 * where we are not allowed to block. Note that this is 1505 * actually reliable test even without the lock - the caller 1506 * must assure that nobody can come after the DQUOT_DROP and 1507 * add quota pointers back anyway. 1508 */ 1509 dquots = i_dquot(inode); 1510 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1511 if (dquots[cnt]) 1512 break; 1513 } 1514 1515 if (cnt < MAXQUOTAS) 1516 __dquot_drop(inode); 1517 } 1518 EXPORT_SYMBOL(dquot_drop); 1519 1520 /* 1521 * inode_reserved_space is managed internally by quota, and protected by 1522 * i_lock similar to i_blocks+i_bytes. 1523 */ 1524 static qsize_t *inode_reserved_space(struct inode * inode) 1525 { 1526 /* Filesystem must explicitly define it's own method in order to use 1527 * quota reservation interface */ 1528 BUG_ON(!inode->i_sb->dq_op->get_reserved_space); 1529 return inode->i_sb->dq_op->get_reserved_space(inode); 1530 } 1531 1532 void inode_add_rsv_space(struct inode *inode, qsize_t number) 1533 { 1534 spin_lock(&inode->i_lock); 1535 *inode_reserved_space(inode) += number; 1536 spin_unlock(&inode->i_lock); 1537 } 1538 EXPORT_SYMBOL(inode_add_rsv_space); 1539 1540 void inode_claim_rsv_space(struct inode *inode, qsize_t number) 1541 { 1542 spin_lock(&inode->i_lock); 1543 *inode_reserved_space(inode) -= number; 1544 __inode_add_bytes(inode, number); 1545 spin_unlock(&inode->i_lock); 1546 } 1547 EXPORT_SYMBOL(inode_claim_rsv_space); 1548 1549 void inode_reclaim_rsv_space(struct inode *inode, qsize_t number) 1550 { 1551 spin_lock(&inode->i_lock); 1552 *inode_reserved_space(inode) += number; 1553 __inode_sub_bytes(inode, number); 1554 spin_unlock(&inode->i_lock); 1555 } 1556 EXPORT_SYMBOL(inode_reclaim_rsv_space); 1557 1558 void inode_sub_rsv_space(struct inode *inode, qsize_t number) 1559 { 1560 spin_lock(&inode->i_lock); 1561 *inode_reserved_space(inode) -= number; 1562 spin_unlock(&inode->i_lock); 1563 } 1564 EXPORT_SYMBOL(inode_sub_rsv_space); 1565 1566 static qsize_t inode_get_rsv_space(struct inode *inode) 1567 { 1568 qsize_t ret; 1569 1570 if (!inode->i_sb->dq_op->get_reserved_space) 1571 return 0; 1572 spin_lock(&inode->i_lock); 1573 ret = *inode_reserved_space(inode); 1574 spin_unlock(&inode->i_lock); 1575 return ret; 1576 } 1577 1578 static void inode_incr_space(struct inode *inode, qsize_t number, 1579 int reserve) 1580 { 1581 if (reserve) 1582 inode_add_rsv_space(inode, number); 1583 else 1584 inode_add_bytes(inode, number); 1585 } 1586 1587 static void inode_decr_space(struct inode *inode, qsize_t number, int reserve) 1588 { 1589 if (reserve) 1590 inode_sub_rsv_space(inode, number); 1591 else 1592 inode_sub_bytes(inode, number); 1593 } 1594 1595 /* 1596 * This functions updates i_blocks+i_bytes fields and quota information 1597 * (together with appropriate checks). 1598 * 1599 * NOTE: We absolutely rely on the fact that caller dirties the inode 1600 * (usually helpers in quotaops.h care about this) and holds a handle for 1601 * the current transaction so that dquot write and inode write go into the 1602 * same transaction. 1603 */ 1604 1605 /* 1606 * This operation can block, but only after everything is updated 1607 */ 1608 int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags) 1609 { 1610 int cnt, ret = 0, index; 1611 struct dquot_warn warn[MAXQUOTAS]; 1612 int reserve = flags & DQUOT_SPACE_RESERVE; 1613 struct dquot **dquots; 1614 1615 if (!dquot_active(inode)) { 1616 inode_incr_space(inode, number, reserve); 1617 goto out; 1618 } 1619 1620 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1621 warn[cnt].w_type = QUOTA_NL_NOWARN; 1622 1623 dquots = i_dquot(inode); 1624 index = srcu_read_lock(&dquot_srcu); 1625 spin_lock(&dq_data_lock); 1626 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1627 if (!dquots[cnt]) 1628 continue; 1629 ret = check_bdq(dquots[cnt], number, 1630 !(flags & DQUOT_SPACE_WARN), &warn[cnt]); 1631 if (ret && !(flags & DQUOT_SPACE_NOFAIL)) { 1632 spin_unlock(&dq_data_lock); 1633 goto out_flush_warn; 1634 } 1635 } 1636 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1637 if (!dquots[cnt]) 1638 continue; 1639 if (reserve) 1640 dquot_resv_space(dquots[cnt], number); 1641 else 1642 dquot_incr_space(dquots[cnt], number); 1643 } 1644 inode_incr_space(inode, number, reserve); 1645 spin_unlock(&dq_data_lock); 1646 1647 if (reserve) 1648 goto out_flush_warn; 1649 mark_all_dquot_dirty(dquots); 1650 out_flush_warn: 1651 srcu_read_unlock(&dquot_srcu, index); 1652 flush_warnings(warn); 1653 out: 1654 return ret; 1655 } 1656 EXPORT_SYMBOL(__dquot_alloc_space); 1657 1658 /* 1659 * This operation can block, but only after everything is updated 1660 */ 1661 int dquot_alloc_inode(struct inode *inode) 1662 { 1663 int cnt, ret = 0, index; 1664 struct dquot_warn warn[MAXQUOTAS]; 1665 struct dquot * const *dquots; 1666 1667 if (!dquot_active(inode)) 1668 return 0; 1669 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1670 warn[cnt].w_type = QUOTA_NL_NOWARN; 1671 1672 dquots = i_dquot(inode); 1673 index = srcu_read_lock(&dquot_srcu); 1674 spin_lock(&dq_data_lock); 1675 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1676 if (!dquots[cnt]) 1677 continue; 1678 ret = check_idq(dquots[cnt], 1, &warn[cnt]); 1679 if (ret) 1680 goto warn_put_all; 1681 } 1682 1683 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1684 if (!dquots[cnt]) 1685 continue; 1686 dquot_incr_inodes(dquots[cnt], 1); 1687 } 1688 1689 warn_put_all: 1690 spin_unlock(&dq_data_lock); 1691 if (ret == 0) 1692 mark_all_dquot_dirty(dquots); 1693 srcu_read_unlock(&dquot_srcu, index); 1694 flush_warnings(warn); 1695 return ret; 1696 } 1697 EXPORT_SYMBOL(dquot_alloc_inode); 1698 1699 /* 1700 * Convert in-memory reserved quotas to real consumed quotas 1701 */ 1702 int dquot_claim_space_nodirty(struct inode *inode, qsize_t number) 1703 { 1704 struct dquot **dquots; 1705 int cnt, index; 1706 1707 if (!dquot_active(inode)) { 1708 inode_claim_rsv_space(inode, number); 1709 return 0; 1710 } 1711 1712 dquots = i_dquot(inode); 1713 index = srcu_read_lock(&dquot_srcu); 1714 spin_lock(&dq_data_lock); 1715 /* Claim reserved quotas to allocated quotas */ 1716 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1717 if (dquots[cnt]) 1718 dquot_claim_reserved_space(dquots[cnt], number); 1719 } 1720 /* Update inode bytes */ 1721 inode_claim_rsv_space(inode, number); 1722 spin_unlock(&dq_data_lock); 1723 mark_all_dquot_dirty(dquots); 1724 srcu_read_unlock(&dquot_srcu, index); 1725 return 0; 1726 } 1727 EXPORT_SYMBOL(dquot_claim_space_nodirty); 1728 1729 /* 1730 * Convert allocated space back to in-memory reserved quotas 1731 */ 1732 void dquot_reclaim_space_nodirty(struct inode *inode, qsize_t number) 1733 { 1734 struct dquot **dquots; 1735 int cnt, index; 1736 1737 if (!dquot_active(inode)) { 1738 inode_reclaim_rsv_space(inode, number); 1739 return; 1740 } 1741 1742 dquots = i_dquot(inode); 1743 index = srcu_read_lock(&dquot_srcu); 1744 spin_lock(&dq_data_lock); 1745 /* Claim reserved quotas to allocated quotas */ 1746 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1747 if (dquots[cnt]) 1748 dquot_reclaim_reserved_space(dquots[cnt], number); 1749 } 1750 /* Update inode bytes */ 1751 inode_reclaim_rsv_space(inode, number); 1752 spin_unlock(&dq_data_lock); 1753 mark_all_dquot_dirty(dquots); 1754 srcu_read_unlock(&dquot_srcu, index); 1755 return; 1756 } 1757 EXPORT_SYMBOL(dquot_reclaim_space_nodirty); 1758 1759 /* 1760 * This operation can block, but only after everything is updated 1761 */ 1762 void __dquot_free_space(struct inode *inode, qsize_t number, int flags) 1763 { 1764 unsigned int cnt; 1765 struct dquot_warn warn[MAXQUOTAS]; 1766 struct dquot **dquots; 1767 int reserve = flags & DQUOT_SPACE_RESERVE, index; 1768 1769 if (!dquot_active(inode)) { 1770 inode_decr_space(inode, number, reserve); 1771 return; 1772 } 1773 1774 dquots = i_dquot(inode); 1775 index = srcu_read_lock(&dquot_srcu); 1776 spin_lock(&dq_data_lock); 1777 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1778 int wtype; 1779 1780 warn[cnt].w_type = QUOTA_NL_NOWARN; 1781 if (!dquots[cnt]) 1782 continue; 1783 wtype = info_bdq_free(dquots[cnt], number); 1784 if (wtype != QUOTA_NL_NOWARN) 1785 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1786 if (reserve) 1787 dquot_free_reserved_space(dquots[cnt], number); 1788 else 1789 dquot_decr_space(dquots[cnt], number); 1790 } 1791 inode_decr_space(inode, number, reserve); 1792 spin_unlock(&dq_data_lock); 1793 1794 if (reserve) 1795 goto out_unlock; 1796 mark_all_dquot_dirty(dquots); 1797 out_unlock: 1798 srcu_read_unlock(&dquot_srcu, index); 1799 flush_warnings(warn); 1800 } 1801 EXPORT_SYMBOL(__dquot_free_space); 1802 1803 /* 1804 * This operation can block, but only after everything is updated 1805 */ 1806 void dquot_free_inode(struct inode *inode) 1807 { 1808 unsigned int cnt; 1809 struct dquot_warn warn[MAXQUOTAS]; 1810 struct dquot * const *dquots; 1811 int index; 1812 1813 if (!dquot_active(inode)) 1814 return; 1815 1816 dquots = i_dquot(inode); 1817 index = srcu_read_lock(&dquot_srcu); 1818 spin_lock(&dq_data_lock); 1819 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1820 int wtype; 1821 1822 warn[cnt].w_type = QUOTA_NL_NOWARN; 1823 if (!dquots[cnt]) 1824 continue; 1825 wtype = info_idq_free(dquots[cnt], 1); 1826 if (wtype != QUOTA_NL_NOWARN) 1827 prepare_warning(&warn[cnt], dquots[cnt], wtype); 1828 dquot_decr_inodes(dquots[cnt], 1); 1829 } 1830 spin_unlock(&dq_data_lock); 1831 mark_all_dquot_dirty(dquots); 1832 srcu_read_unlock(&dquot_srcu, index); 1833 flush_warnings(warn); 1834 } 1835 EXPORT_SYMBOL(dquot_free_inode); 1836 1837 /* 1838 * Transfer the number of inode and blocks from one diskquota to an other. 1839 * On success, dquot references in transfer_to are consumed and references 1840 * to original dquots that need to be released are placed there. On failure, 1841 * references are kept untouched. 1842 * 1843 * This operation can block, but only after everything is updated 1844 * A transaction must be started when entering this function. 1845 * 1846 * We are holding reference on transfer_from & transfer_to, no need to 1847 * protect them by srcu_read_lock(). 1848 */ 1849 int __dquot_transfer(struct inode *inode, struct dquot **transfer_to) 1850 { 1851 qsize_t space, cur_space; 1852 qsize_t rsv_space = 0; 1853 struct dquot *transfer_from[MAXQUOTAS] = {}; 1854 int cnt, ret = 0; 1855 char is_valid[MAXQUOTAS] = {}; 1856 struct dquot_warn warn_to[MAXQUOTAS]; 1857 struct dquot_warn warn_from_inodes[MAXQUOTAS]; 1858 struct dquot_warn warn_from_space[MAXQUOTAS]; 1859 1860 if (IS_NOQUOTA(inode)) 1861 return 0; 1862 /* Initialize the arrays */ 1863 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1864 warn_to[cnt].w_type = QUOTA_NL_NOWARN; 1865 warn_from_inodes[cnt].w_type = QUOTA_NL_NOWARN; 1866 warn_from_space[cnt].w_type = QUOTA_NL_NOWARN; 1867 } 1868 1869 spin_lock(&dq_data_lock); 1870 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1871 spin_unlock(&dq_data_lock); 1872 return 0; 1873 } 1874 cur_space = inode_get_bytes(inode); 1875 rsv_space = inode_get_rsv_space(inode); 1876 space = cur_space + rsv_space; 1877 /* Build the transfer_from list and check the limits */ 1878 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1879 /* 1880 * Skip changes for same uid or gid or for turned off quota-type. 1881 */ 1882 if (!transfer_to[cnt]) 1883 continue; 1884 /* Avoid races with quotaoff() */ 1885 if (!sb_has_quota_active(inode->i_sb, cnt)) 1886 continue; 1887 is_valid[cnt] = 1; 1888 transfer_from[cnt] = i_dquot(inode)[cnt]; 1889 ret = check_idq(transfer_to[cnt], 1, &warn_to[cnt]); 1890 if (ret) 1891 goto over_quota; 1892 ret = check_bdq(transfer_to[cnt], space, 0, &warn_to[cnt]); 1893 if (ret) 1894 goto over_quota; 1895 } 1896 1897 /* 1898 * Finally perform the needed transfer from transfer_from to transfer_to 1899 */ 1900 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1901 if (!is_valid[cnt]) 1902 continue; 1903 /* Due to IO error we might not have transfer_from[] structure */ 1904 if (transfer_from[cnt]) { 1905 int wtype; 1906 wtype = info_idq_free(transfer_from[cnt], 1); 1907 if (wtype != QUOTA_NL_NOWARN) 1908 prepare_warning(&warn_from_inodes[cnt], 1909 transfer_from[cnt], wtype); 1910 wtype = info_bdq_free(transfer_from[cnt], space); 1911 if (wtype != QUOTA_NL_NOWARN) 1912 prepare_warning(&warn_from_space[cnt], 1913 transfer_from[cnt], wtype); 1914 dquot_decr_inodes(transfer_from[cnt], 1); 1915 dquot_decr_space(transfer_from[cnt], cur_space); 1916 dquot_free_reserved_space(transfer_from[cnt], 1917 rsv_space); 1918 } 1919 1920 dquot_incr_inodes(transfer_to[cnt], 1); 1921 dquot_incr_space(transfer_to[cnt], cur_space); 1922 dquot_resv_space(transfer_to[cnt], rsv_space); 1923 1924 i_dquot(inode)[cnt] = transfer_to[cnt]; 1925 } 1926 spin_unlock(&dq_data_lock); 1927 1928 mark_all_dquot_dirty(transfer_from); 1929 mark_all_dquot_dirty(transfer_to); 1930 flush_warnings(warn_to); 1931 flush_warnings(warn_from_inodes); 1932 flush_warnings(warn_from_space); 1933 /* Pass back references to put */ 1934 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1935 if (is_valid[cnt]) 1936 transfer_to[cnt] = transfer_from[cnt]; 1937 return 0; 1938 over_quota: 1939 spin_unlock(&dq_data_lock); 1940 flush_warnings(warn_to); 1941 return ret; 1942 } 1943 EXPORT_SYMBOL(__dquot_transfer); 1944 1945 /* Wrapper for transferring ownership of an inode for uid/gid only 1946 * Called from FSXXX_setattr() 1947 */ 1948 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1949 { 1950 struct dquot *transfer_to[MAXQUOTAS] = {}; 1951 struct super_block *sb = inode->i_sb; 1952 int ret; 1953 1954 if (!dquot_active(inode)) 1955 return 0; 1956 1957 if (iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) 1958 transfer_to[USRQUOTA] = dqget(sb, make_kqid_uid(iattr->ia_uid)); 1959 if (iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid)) 1960 transfer_to[GRPQUOTA] = dqget(sb, make_kqid_gid(iattr->ia_gid)); 1961 1962 ret = __dquot_transfer(inode, transfer_to); 1963 dqput_all(transfer_to); 1964 return ret; 1965 } 1966 EXPORT_SYMBOL(dquot_transfer); 1967 1968 /* 1969 * Write info of quota file to disk 1970 */ 1971 int dquot_commit_info(struct super_block *sb, int type) 1972 { 1973 int ret; 1974 struct quota_info *dqopt = sb_dqopt(sb); 1975 1976 mutex_lock(&dqopt->dqio_mutex); 1977 ret = dqopt->ops[type]->write_file_info(sb, type); 1978 mutex_unlock(&dqopt->dqio_mutex); 1979 return ret; 1980 } 1981 EXPORT_SYMBOL(dquot_commit_info); 1982 1983 /* 1984 * Definitions of diskquota operations. 1985 */ 1986 const struct dquot_operations dquot_operations = { 1987 .write_dquot = dquot_commit, 1988 .acquire_dquot = dquot_acquire, 1989 .release_dquot = dquot_release, 1990 .mark_dirty = dquot_mark_dquot_dirty, 1991 .write_info = dquot_commit_info, 1992 .alloc_dquot = dquot_alloc, 1993 .destroy_dquot = dquot_destroy, 1994 }; 1995 EXPORT_SYMBOL(dquot_operations); 1996 1997 /* 1998 * Generic helper for ->open on filesystems supporting disk quotas. 1999 */ 2000 int dquot_file_open(struct inode *inode, struct file *file) 2001 { 2002 int error; 2003 2004 error = generic_file_open(inode, file); 2005 if (!error && (file->f_mode & FMODE_WRITE)) 2006 dquot_initialize(inode); 2007 return error; 2008 } 2009 EXPORT_SYMBOL(dquot_file_open); 2010 2011 /* 2012 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 2013 */ 2014 int dquot_disable(struct super_block *sb, int type, unsigned int flags) 2015 { 2016 int cnt, ret = 0; 2017 struct quota_info *dqopt = sb_dqopt(sb); 2018 struct inode *toputinode[MAXQUOTAS]; 2019 2020 /* Cannot turn off usage accounting without turning off limits, or 2021 * suspend quotas and simultaneously turn quotas off. */ 2022 if ((flags & DQUOT_USAGE_ENABLED && !(flags & DQUOT_LIMITS_ENABLED)) 2023 || (flags & DQUOT_SUSPENDED && flags & (DQUOT_LIMITS_ENABLED | 2024 DQUOT_USAGE_ENABLED))) 2025 return -EINVAL; 2026 2027 /* We need to serialize quota_off() for device */ 2028 mutex_lock(&dqopt->dqonoff_mutex); 2029 2030 /* 2031 * Skip everything if there's nothing to do. We have to do this because 2032 * sometimes we are called when fill_super() failed and calling 2033 * sync_fs() in such cases does no good. 2034 */ 2035 if (!sb_any_quota_loaded(sb)) { 2036 mutex_unlock(&dqopt->dqonoff_mutex); 2037 return 0; 2038 } 2039 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2040 toputinode[cnt] = NULL; 2041 if (type != -1 && cnt != type) 2042 continue; 2043 if (!sb_has_quota_loaded(sb, cnt)) 2044 continue; 2045 2046 if (flags & DQUOT_SUSPENDED) { 2047 spin_lock(&dq_state_lock); 2048 dqopt->flags |= 2049 dquot_state_flag(DQUOT_SUSPENDED, cnt); 2050 spin_unlock(&dq_state_lock); 2051 } else { 2052 spin_lock(&dq_state_lock); 2053 dqopt->flags &= ~dquot_state_flag(flags, cnt); 2054 /* Turning off suspended quotas? */ 2055 if (!sb_has_quota_loaded(sb, cnt) && 2056 sb_has_quota_suspended(sb, cnt)) { 2057 dqopt->flags &= ~dquot_state_flag( 2058 DQUOT_SUSPENDED, cnt); 2059 spin_unlock(&dq_state_lock); 2060 iput(dqopt->files[cnt]); 2061 dqopt->files[cnt] = NULL; 2062 continue; 2063 } 2064 spin_unlock(&dq_state_lock); 2065 } 2066 2067 /* We still have to keep quota loaded? */ 2068 if (sb_has_quota_loaded(sb, cnt) && !(flags & DQUOT_SUSPENDED)) 2069 continue; 2070 2071 /* Note: these are blocking operations */ 2072 drop_dquot_ref(sb, cnt); 2073 invalidate_dquots(sb, cnt); 2074 /* 2075 * Now all dquots should be invalidated, all writes done so we 2076 * should be only users of the info. No locks needed. 2077 */ 2078 if (info_dirty(&dqopt->info[cnt])) 2079 sb->dq_op->write_info(sb, cnt); 2080 if (dqopt->ops[cnt]->free_file_info) 2081 dqopt->ops[cnt]->free_file_info(sb, cnt); 2082 put_quota_format(dqopt->info[cnt].dqi_format); 2083 2084 toputinode[cnt] = dqopt->files[cnt]; 2085 if (!sb_has_quota_loaded(sb, cnt)) 2086 dqopt->files[cnt] = NULL; 2087 dqopt->info[cnt].dqi_flags = 0; 2088 dqopt->info[cnt].dqi_igrace = 0; 2089 dqopt->info[cnt].dqi_bgrace = 0; 2090 dqopt->ops[cnt] = NULL; 2091 } 2092 mutex_unlock(&dqopt->dqonoff_mutex); 2093 2094 /* Skip syncing and setting flags if quota files are hidden */ 2095 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2096 goto put_inodes; 2097 2098 /* Sync the superblock so that buffers with quota data are written to 2099 * disk (and so userspace sees correct data afterwards). */ 2100 if (sb->s_op->sync_fs) 2101 sb->s_op->sync_fs(sb, 1); 2102 sync_blockdev(sb->s_bdev); 2103 /* Now the quota files are just ordinary files and we can set the 2104 * inode flags back. Moreover we discard the pagecache so that 2105 * userspace sees the writes we did bypassing the pagecache. We 2106 * must also discard the blockdev buffers so that we see the 2107 * changes done by userspace on the next quotaon() */ 2108 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2109 if (toputinode[cnt]) { 2110 mutex_lock(&dqopt->dqonoff_mutex); 2111 /* If quota was reenabled in the meantime, we have 2112 * nothing to do */ 2113 if (!sb_has_quota_loaded(sb, cnt)) { 2114 mutex_lock(&toputinode[cnt]->i_mutex); 2115 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 2116 S_NOATIME | S_NOQUOTA); 2117 truncate_inode_pages(&toputinode[cnt]->i_data, 2118 0); 2119 mutex_unlock(&toputinode[cnt]->i_mutex); 2120 mark_inode_dirty_sync(toputinode[cnt]); 2121 } 2122 mutex_unlock(&dqopt->dqonoff_mutex); 2123 } 2124 if (sb->s_bdev) 2125 invalidate_bdev(sb->s_bdev); 2126 put_inodes: 2127 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 2128 if (toputinode[cnt]) { 2129 /* On remount RO, we keep the inode pointer so that we 2130 * can reenable quota on the subsequent remount RW. We 2131 * have to check 'flags' variable and not use sb_has_ 2132 * function because another quotaon / quotaoff could 2133 * change global state before we got here. We refuse 2134 * to suspend quotas when there is pending delete on 2135 * the quota file... */ 2136 if (!(flags & DQUOT_SUSPENDED)) 2137 iput(toputinode[cnt]); 2138 else if (!toputinode[cnt]->i_nlink) 2139 ret = -EBUSY; 2140 } 2141 return ret; 2142 } 2143 EXPORT_SYMBOL(dquot_disable); 2144 2145 int dquot_quota_off(struct super_block *sb, int type) 2146 { 2147 return dquot_disable(sb, type, 2148 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2149 } 2150 EXPORT_SYMBOL(dquot_quota_off); 2151 2152 /* 2153 * Turn quotas on on a device 2154 */ 2155 2156 /* 2157 * Helper function to turn quotas on when we already have the inode of 2158 * quota file and no quota information is loaded. 2159 */ 2160 static int vfs_load_quota_inode(struct inode *inode, int type, int format_id, 2161 unsigned int flags) 2162 { 2163 struct quota_format_type *fmt = find_quota_format(format_id); 2164 struct super_block *sb = inode->i_sb; 2165 struct quota_info *dqopt = sb_dqopt(sb); 2166 int error; 2167 int oldflags = -1; 2168 2169 if (!fmt) 2170 return -ESRCH; 2171 if (!S_ISREG(inode->i_mode)) { 2172 error = -EACCES; 2173 goto out_fmt; 2174 } 2175 if (IS_RDONLY(inode)) { 2176 error = -EROFS; 2177 goto out_fmt; 2178 } 2179 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 2180 error = -EINVAL; 2181 goto out_fmt; 2182 } 2183 /* Usage always has to be set... */ 2184 if (!(flags & DQUOT_USAGE_ENABLED)) { 2185 error = -EINVAL; 2186 goto out_fmt; 2187 } 2188 2189 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2190 /* As we bypass the pagecache we must now flush all the 2191 * dirty data and invalidate caches so that kernel sees 2192 * changes from userspace. It is not enough to just flush 2193 * the quota file since if blocksize < pagesize, invalidation 2194 * of the cache could fail because of other unrelated dirty 2195 * data */ 2196 sync_filesystem(sb); 2197 invalidate_bdev(sb->s_bdev); 2198 } 2199 mutex_lock(&dqopt->dqonoff_mutex); 2200 if (sb_has_quota_loaded(sb, type)) { 2201 error = -EBUSY; 2202 goto out_lock; 2203 } 2204 2205 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) { 2206 /* We don't want quota and atime on quota files (deadlocks 2207 * possible) Also nobody should write to the file - we use 2208 * special IO operations which ignore the immutable bit. */ 2209 mutex_lock(&inode->i_mutex); 2210 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | 2211 S_NOQUOTA); 2212 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 2213 mutex_unlock(&inode->i_mutex); 2214 /* 2215 * When S_NOQUOTA is set, remove dquot references as no more 2216 * references can be added 2217 */ 2218 __dquot_drop(inode); 2219 } 2220 2221 error = -EIO; 2222 dqopt->files[type] = igrab(inode); 2223 if (!dqopt->files[type]) 2224 goto out_lock; 2225 error = -EINVAL; 2226 if (!fmt->qf_ops->check_quota_file(sb, type)) 2227 goto out_file_init; 2228 2229 dqopt->ops[type] = fmt->qf_ops; 2230 dqopt->info[type].dqi_format = fmt; 2231 dqopt->info[type].dqi_fmt_id = format_id; 2232 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 2233 mutex_lock(&dqopt->dqio_mutex); 2234 error = dqopt->ops[type]->read_file_info(sb, type); 2235 if (error < 0) { 2236 mutex_unlock(&dqopt->dqio_mutex); 2237 goto out_file_init; 2238 } 2239 if (dqopt->flags & DQUOT_QUOTA_SYS_FILE) 2240 dqopt->info[type].dqi_flags |= DQF_SYS_FILE; 2241 mutex_unlock(&dqopt->dqio_mutex); 2242 spin_lock(&dq_state_lock); 2243 dqopt->flags |= dquot_state_flag(flags, type); 2244 spin_unlock(&dq_state_lock); 2245 2246 add_dquot_ref(sb, type); 2247 mutex_unlock(&dqopt->dqonoff_mutex); 2248 2249 return 0; 2250 2251 out_file_init: 2252 dqopt->files[type] = NULL; 2253 iput(inode); 2254 out_lock: 2255 if (oldflags != -1) { 2256 mutex_lock(&inode->i_mutex); 2257 /* Set the flags back (in the case of accidental quotaon() 2258 * on a wrong file we don't want to mess up the flags) */ 2259 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 2260 inode->i_flags |= oldflags; 2261 mutex_unlock(&inode->i_mutex); 2262 } 2263 mutex_unlock(&dqopt->dqonoff_mutex); 2264 out_fmt: 2265 put_quota_format(fmt); 2266 2267 return error; 2268 } 2269 2270 /* Reenable quotas on remount RW */ 2271 int dquot_resume(struct super_block *sb, int type) 2272 { 2273 struct quota_info *dqopt = sb_dqopt(sb); 2274 struct inode *inode; 2275 int ret = 0, cnt; 2276 unsigned int flags; 2277 2278 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 2279 if (type != -1 && cnt != type) 2280 continue; 2281 2282 mutex_lock(&dqopt->dqonoff_mutex); 2283 if (!sb_has_quota_suspended(sb, cnt)) { 2284 mutex_unlock(&dqopt->dqonoff_mutex); 2285 continue; 2286 } 2287 inode = dqopt->files[cnt]; 2288 dqopt->files[cnt] = NULL; 2289 spin_lock(&dq_state_lock); 2290 flags = dqopt->flags & dquot_state_flag(DQUOT_USAGE_ENABLED | 2291 DQUOT_LIMITS_ENABLED, 2292 cnt); 2293 dqopt->flags &= ~dquot_state_flag(DQUOT_STATE_FLAGS, cnt); 2294 spin_unlock(&dq_state_lock); 2295 mutex_unlock(&dqopt->dqonoff_mutex); 2296 2297 flags = dquot_generic_flag(flags, cnt); 2298 ret = vfs_load_quota_inode(inode, cnt, 2299 dqopt->info[cnt].dqi_fmt_id, flags); 2300 iput(inode); 2301 } 2302 2303 return ret; 2304 } 2305 EXPORT_SYMBOL(dquot_resume); 2306 2307 int dquot_quota_on(struct super_block *sb, int type, int format_id, 2308 struct path *path) 2309 { 2310 int error = security_quota_on(path->dentry); 2311 if (error) 2312 return error; 2313 /* Quota file not on the same filesystem? */ 2314 if (path->dentry->d_sb != sb) 2315 error = -EXDEV; 2316 else 2317 error = vfs_load_quota_inode(path->dentry->d_inode, type, 2318 format_id, DQUOT_USAGE_ENABLED | 2319 DQUOT_LIMITS_ENABLED); 2320 return error; 2321 } 2322 EXPORT_SYMBOL(dquot_quota_on); 2323 2324 /* 2325 * More powerful function for turning on quotas allowing setting 2326 * of individual quota flags 2327 */ 2328 int dquot_enable(struct inode *inode, int type, int format_id, 2329 unsigned int flags) 2330 { 2331 int ret = 0; 2332 struct super_block *sb = inode->i_sb; 2333 struct quota_info *dqopt = sb_dqopt(sb); 2334 2335 /* Just unsuspend quotas? */ 2336 BUG_ON(flags & DQUOT_SUSPENDED); 2337 2338 if (!flags) 2339 return 0; 2340 /* Just updating flags needed? */ 2341 if (sb_has_quota_loaded(sb, type)) { 2342 mutex_lock(&dqopt->dqonoff_mutex); 2343 /* Now do a reliable test... */ 2344 if (!sb_has_quota_loaded(sb, type)) { 2345 mutex_unlock(&dqopt->dqonoff_mutex); 2346 goto load_quota; 2347 } 2348 if (flags & DQUOT_USAGE_ENABLED && 2349 sb_has_quota_usage_enabled(sb, type)) { 2350 ret = -EBUSY; 2351 goto out_lock; 2352 } 2353 if (flags & DQUOT_LIMITS_ENABLED && 2354 sb_has_quota_limits_enabled(sb, type)) { 2355 ret = -EBUSY; 2356 goto out_lock; 2357 } 2358 spin_lock(&dq_state_lock); 2359 sb_dqopt(sb)->flags |= dquot_state_flag(flags, type); 2360 spin_unlock(&dq_state_lock); 2361 out_lock: 2362 mutex_unlock(&dqopt->dqonoff_mutex); 2363 return ret; 2364 } 2365 2366 load_quota: 2367 return vfs_load_quota_inode(inode, type, format_id, flags); 2368 } 2369 EXPORT_SYMBOL(dquot_enable); 2370 2371 /* 2372 * This function is used when filesystem needs to initialize quotas 2373 * during mount time. 2374 */ 2375 int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 2376 int format_id, int type) 2377 { 2378 struct dentry *dentry; 2379 int error; 2380 2381 mutex_lock(&sb->s_root->d_inode->i_mutex); 2382 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 2383 mutex_unlock(&sb->s_root->d_inode->i_mutex); 2384 if (IS_ERR(dentry)) 2385 return PTR_ERR(dentry); 2386 2387 if (!dentry->d_inode) { 2388 error = -ENOENT; 2389 goto out; 2390 } 2391 2392 error = security_quota_on(dentry); 2393 if (!error) 2394 error = vfs_load_quota_inode(dentry->d_inode, type, format_id, 2395 DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED); 2396 2397 out: 2398 dput(dentry); 2399 return error; 2400 } 2401 EXPORT_SYMBOL(dquot_quota_on_mount); 2402 2403 static int dquot_quota_enable(struct super_block *sb, unsigned int flags) 2404 { 2405 int ret; 2406 int type; 2407 struct quota_info *dqopt = sb_dqopt(sb); 2408 2409 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2410 return -ENOSYS; 2411 /* Accounting cannot be turned on while fs is mounted */ 2412 flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT); 2413 if (!flags) 2414 return -EINVAL; 2415 for (type = 0; type < MAXQUOTAS; type++) { 2416 if (!(flags & qtype_enforce_flag(type))) 2417 continue; 2418 /* Can't enforce without accounting */ 2419 if (!sb_has_quota_usage_enabled(sb, type)) 2420 return -EINVAL; 2421 ret = dquot_enable(dqopt->files[type], type, 2422 dqopt->info[type].dqi_fmt_id, 2423 DQUOT_LIMITS_ENABLED); 2424 if (ret < 0) 2425 goto out_err; 2426 } 2427 return 0; 2428 out_err: 2429 /* Backout enforcement enablement we already did */ 2430 for (type--; type >= 0; type--) { 2431 if (flags & qtype_enforce_flag(type)) 2432 dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2433 } 2434 /* Error code translation for better compatibility with XFS */ 2435 if (ret == -EBUSY) 2436 ret = -EEXIST; 2437 return ret; 2438 } 2439 2440 static int dquot_quota_disable(struct super_block *sb, unsigned int flags) 2441 { 2442 int ret; 2443 int type; 2444 struct quota_info *dqopt = sb_dqopt(sb); 2445 2446 if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE)) 2447 return -ENOSYS; 2448 /* 2449 * We don't support turning off accounting via quotactl. In principle 2450 * quota infrastructure can do this but filesystems don't expect 2451 * userspace to be able to do it. 2452 */ 2453 if (flags & 2454 (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT)) 2455 return -EOPNOTSUPP; 2456 2457 /* Filter out limits not enabled */ 2458 for (type = 0; type < MAXQUOTAS; type++) 2459 if (!sb_has_quota_limits_enabled(sb, type)) 2460 flags &= ~qtype_enforce_flag(type); 2461 /* Nothing left? */ 2462 if (!flags) 2463 return -EEXIST; 2464 for (type = 0; type < MAXQUOTAS; type++) { 2465 if (flags & qtype_enforce_flag(type)) { 2466 ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED); 2467 if (ret < 0) 2468 goto out_err; 2469 } 2470 } 2471 return 0; 2472 out_err: 2473 /* Backout enforcement disabling we already did */ 2474 for (type--; type >= 0; type--) { 2475 if (flags & qtype_enforce_flag(type)) 2476 dquot_enable(dqopt->files[type], type, 2477 dqopt->info[type].dqi_fmt_id, 2478 DQUOT_LIMITS_ENABLED); 2479 } 2480 return ret; 2481 } 2482 2483 /* Generic routine for getting common part of quota structure */ 2484 static void do_get_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2485 { 2486 struct mem_dqblk *dm = &dquot->dq_dqb; 2487 2488 memset(di, 0, sizeof(*di)); 2489 spin_lock(&dq_data_lock); 2490 di->d_spc_hardlimit = dm->dqb_bhardlimit; 2491 di->d_spc_softlimit = dm->dqb_bsoftlimit; 2492 di->d_ino_hardlimit = dm->dqb_ihardlimit; 2493 di->d_ino_softlimit = dm->dqb_isoftlimit; 2494 di->d_space = dm->dqb_curspace + dm->dqb_rsvspace; 2495 di->d_ino_count = dm->dqb_curinodes; 2496 di->d_spc_timer = dm->dqb_btime; 2497 di->d_ino_timer = dm->dqb_itime; 2498 spin_unlock(&dq_data_lock); 2499 } 2500 2501 int dquot_get_dqblk(struct super_block *sb, struct kqid qid, 2502 struct qc_dqblk *di) 2503 { 2504 struct dquot *dquot; 2505 2506 dquot = dqget(sb, qid); 2507 if (!dquot) 2508 return -ESRCH; 2509 do_get_dqblk(dquot, di); 2510 dqput(dquot); 2511 2512 return 0; 2513 } 2514 EXPORT_SYMBOL(dquot_get_dqblk); 2515 2516 #define VFS_QC_MASK \ 2517 (QC_SPACE | QC_SPC_SOFT | QC_SPC_HARD | \ 2518 QC_INO_COUNT | QC_INO_SOFT | QC_INO_HARD | \ 2519 QC_SPC_TIMER | QC_INO_TIMER) 2520 2521 /* Generic routine for setting common part of quota structure */ 2522 static int do_set_dqblk(struct dquot *dquot, struct qc_dqblk *di) 2523 { 2524 struct mem_dqblk *dm = &dquot->dq_dqb; 2525 int check_blim = 0, check_ilim = 0; 2526 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_id.type]; 2527 2528 if (di->d_fieldmask & ~VFS_QC_MASK) 2529 return -EINVAL; 2530 2531 if (((di->d_fieldmask & QC_SPC_SOFT) && 2532 di->d_spc_softlimit > dqi->dqi_max_spc_limit) || 2533 ((di->d_fieldmask & QC_SPC_HARD) && 2534 di->d_spc_hardlimit > dqi->dqi_max_spc_limit) || 2535 ((di->d_fieldmask & QC_INO_SOFT) && 2536 (di->d_ino_softlimit > dqi->dqi_max_ino_limit)) || 2537 ((di->d_fieldmask & QC_INO_HARD) && 2538 (di->d_ino_hardlimit > dqi->dqi_max_ino_limit))) 2539 return -ERANGE; 2540 2541 spin_lock(&dq_data_lock); 2542 if (di->d_fieldmask & QC_SPACE) { 2543 dm->dqb_curspace = di->d_space - dm->dqb_rsvspace; 2544 check_blim = 1; 2545 set_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags); 2546 } 2547 2548 if (di->d_fieldmask & QC_SPC_SOFT) 2549 dm->dqb_bsoftlimit = di->d_spc_softlimit; 2550 if (di->d_fieldmask & QC_SPC_HARD) 2551 dm->dqb_bhardlimit = di->d_spc_hardlimit; 2552 if (di->d_fieldmask & (QC_SPC_SOFT | QC_SPC_HARD)) { 2553 check_blim = 1; 2554 set_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags); 2555 } 2556 2557 if (di->d_fieldmask & QC_INO_COUNT) { 2558 dm->dqb_curinodes = di->d_ino_count; 2559 check_ilim = 1; 2560 set_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags); 2561 } 2562 2563 if (di->d_fieldmask & QC_INO_SOFT) 2564 dm->dqb_isoftlimit = di->d_ino_softlimit; 2565 if (di->d_fieldmask & QC_INO_HARD) 2566 dm->dqb_ihardlimit = di->d_ino_hardlimit; 2567 if (di->d_fieldmask & (QC_INO_SOFT | QC_INO_HARD)) { 2568 check_ilim = 1; 2569 set_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags); 2570 } 2571 2572 if (di->d_fieldmask & QC_SPC_TIMER) { 2573 dm->dqb_btime = di->d_spc_timer; 2574 check_blim = 1; 2575 set_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags); 2576 } 2577 2578 if (di->d_fieldmask & QC_INO_TIMER) { 2579 dm->dqb_itime = di->d_ino_timer; 2580 check_ilim = 1; 2581 set_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags); 2582 } 2583 2584 if (check_blim) { 2585 if (!dm->dqb_bsoftlimit || 2586 dm->dqb_curspace < dm->dqb_bsoftlimit) { 2587 dm->dqb_btime = 0; 2588 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 2589 } else if (!(di->d_fieldmask & QC_SPC_TIMER)) 2590 /* Set grace only if user hasn't provided his own... */ 2591 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 2592 } 2593 if (check_ilim) { 2594 if (!dm->dqb_isoftlimit || 2595 dm->dqb_curinodes < dm->dqb_isoftlimit) { 2596 dm->dqb_itime = 0; 2597 clear_bit(DQ_INODES_B, &dquot->dq_flags); 2598 } else if (!(di->d_fieldmask & QC_INO_TIMER)) 2599 /* Set grace only if user hasn't provided his own... */ 2600 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 2601 } 2602 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || 2603 dm->dqb_isoftlimit) 2604 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 2605 else 2606 set_bit(DQ_FAKE_B, &dquot->dq_flags); 2607 spin_unlock(&dq_data_lock); 2608 mark_dquot_dirty(dquot); 2609 2610 return 0; 2611 } 2612 2613 int dquot_set_dqblk(struct super_block *sb, struct kqid qid, 2614 struct qc_dqblk *di) 2615 { 2616 struct dquot *dquot; 2617 int rc; 2618 2619 dquot = dqget(sb, qid); 2620 if (!dquot) { 2621 rc = -ESRCH; 2622 goto out; 2623 } 2624 rc = do_set_dqblk(dquot, di); 2625 dqput(dquot); 2626 out: 2627 return rc; 2628 } 2629 EXPORT_SYMBOL(dquot_set_dqblk); 2630 2631 /* Generic routine for getting common part of quota file information */ 2632 int dquot_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2633 { 2634 struct mem_dqinfo *mi; 2635 2636 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2637 if (!sb_has_quota_active(sb, type)) { 2638 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2639 return -ESRCH; 2640 } 2641 mi = sb_dqopt(sb)->info + type; 2642 spin_lock(&dq_data_lock); 2643 ii->dqi_bgrace = mi->dqi_bgrace; 2644 ii->dqi_igrace = mi->dqi_igrace; 2645 ii->dqi_flags = mi->dqi_flags & DQF_GETINFO_MASK; 2646 ii->dqi_valid = IIF_ALL; 2647 spin_unlock(&dq_data_lock); 2648 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2649 return 0; 2650 } 2651 EXPORT_SYMBOL(dquot_get_dqinfo); 2652 2653 /* Generic routine for setting common part of quota file information */ 2654 int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2655 { 2656 struct mem_dqinfo *mi; 2657 int err = 0; 2658 2659 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2660 if (!sb_has_quota_active(sb, type)) { 2661 err = -ESRCH; 2662 goto out; 2663 } 2664 mi = sb_dqopt(sb)->info + type; 2665 if (ii->dqi_valid & IIF_FLAGS) { 2666 if (ii->dqi_flags & ~DQF_SETINFO_MASK || 2667 (ii->dqi_flags & DQF_ROOT_SQUASH && 2668 mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) { 2669 err = -EINVAL; 2670 goto out; 2671 } 2672 } 2673 spin_lock(&dq_data_lock); 2674 if (ii->dqi_valid & IIF_BGRACE) 2675 mi->dqi_bgrace = ii->dqi_bgrace; 2676 if (ii->dqi_valid & IIF_IGRACE) 2677 mi->dqi_igrace = ii->dqi_igrace; 2678 if (ii->dqi_valid & IIF_FLAGS) 2679 mi->dqi_flags = (mi->dqi_flags & ~DQF_SETINFO_MASK) | 2680 (ii->dqi_flags & DQF_SETINFO_MASK); 2681 spin_unlock(&dq_data_lock); 2682 mark_info_dirty(sb, type); 2683 /* Force write to disk */ 2684 sb->dq_op->write_info(sb, type); 2685 out: 2686 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2687 return err; 2688 } 2689 EXPORT_SYMBOL(dquot_set_dqinfo); 2690 2691 const struct quotactl_ops dquot_quotactl_ops = { 2692 .quota_on = dquot_quota_on, 2693 .quota_off = dquot_quota_off, 2694 .quota_sync = dquot_quota_sync, 2695 .get_info = dquot_get_dqinfo, 2696 .set_info = dquot_set_dqinfo, 2697 .get_dqblk = dquot_get_dqblk, 2698 .set_dqblk = dquot_set_dqblk 2699 }; 2700 EXPORT_SYMBOL(dquot_quotactl_ops); 2701 2702 const struct quotactl_ops dquot_quotactl_sysfile_ops = { 2703 .quota_enable = dquot_quota_enable, 2704 .quota_disable = dquot_quota_disable, 2705 .quota_sync = dquot_quota_sync, 2706 .get_info = dquot_get_dqinfo, 2707 .set_info = dquot_set_dqinfo, 2708 .get_dqblk = dquot_get_dqblk, 2709 .set_dqblk = dquot_set_dqblk 2710 }; 2711 EXPORT_SYMBOL(dquot_quotactl_sysfile_ops); 2712 2713 static int do_proc_dqstats(struct ctl_table *table, int write, 2714 void __user *buffer, size_t *lenp, loff_t *ppos) 2715 { 2716 unsigned int type = (int *)table->data - dqstats.stat; 2717 2718 /* Update global table */ 2719 dqstats.stat[type] = 2720 percpu_counter_sum_positive(&dqstats.counter[type]); 2721 return proc_dointvec(table, write, buffer, lenp, ppos); 2722 } 2723 2724 static struct ctl_table fs_dqstats_table[] = { 2725 { 2726 .procname = "lookups", 2727 .data = &dqstats.stat[DQST_LOOKUPS], 2728 .maxlen = sizeof(int), 2729 .mode = 0444, 2730 .proc_handler = do_proc_dqstats, 2731 }, 2732 { 2733 .procname = "drops", 2734 .data = &dqstats.stat[DQST_DROPS], 2735 .maxlen = sizeof(int), 2736 .mode = 0444, 2737 .proc_handler = do_proc_dqstats, 2738 }, 2739 { 2740 .procname = "reads", 2741 .data = &dqstats.stat[DQST_READS], 2742 .maxlen = sizeof(int), 2743 .mode = 0444, 2744 .proc_handler = do_proc_dqstats, 2745 }, 2746 { 2747 .procname = "writes", 2748 .data = &dqstats.stat[DQST_WRITES], 2749 .maxlen = sizeof(int), 2750 .mode = 0444, 2751 .proc_handler = do_proc_dqstats, 2752 }, 2753 { 2754 .procname = "cache_hits", 2755 .data = &dqstats.stat[DQST_CACHE_HITS], 2756 .maxlen = sizeof(int), 2757 .mode = 0444, 2758 .proc_handler = do_proc_dqstats, 2759 }, 2760 { 2761 .procname = "allocated_dquots", 2762 .data = &dqstats.stat[DQST_ALLOC_DQUOTS], 2763 .maxlen = sizeof(int), 2764 .mode = 0444, 2765 .proc_handler = do_proc_dqstats, 2766 }, 2767 { 2768 .procname = "free_dquots", 2769 .data = &dqstats.stat[DQST_FREE_DQUOTS], 2770 .maxlen = sizeof(int), 2771 .mode = 0444, 2772 .proc_handler = do_proc_dqstats, 2773 }, 2774 { 2775 .procname = "syncs", 2776 .data = &dqstats.stat[DQST_SYNCS], 2777 .maxlen = sizeof(int), 2778 .mode = 0444, 2779 .proc_handler = do_proc_dqstats, 2780 }, 2781 #ifdef CONFIG_PRINT_QUOTA_WARNING 2782 { 2783 .procname = "warnings", 2784 .data = &flag_print_warnings, 2785 .maxlen = sizeof(int), 2786 .mode = 0644, 2787 .proc_handler = proc_dointvec, 2788 }, 2789 #endif 2790 { }, 2791 }; 2792 2793 static struct ctl_table fs_table[] = { 2794 { 2795 .procname = "quota", 2796 .mode = 0555, 2797 .child = fs_dqstats_table, 2798 }, 2799 { }, 2800 }; 2801 2802 static struct ctl_table sys_table[] = { 2803 { 2804 .procname = "fs", 2805 .mode = 0555, 2806 .child = fs_table, 2807 }, 2808 { }, 2809 }; 2810 2811 static int __init dquot_init(void) 2812 { 2813 int i, ret; 2814 unsigned long nr_hash, order; 2815 2816 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2817 2818 register_sysctl_table(sys_table); 2819 2820 dquot_cachep = kmem_cache_create("dquot", 2821 sizeof(struct dquot), sizeof(unsigned long) * 4, 2822 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2823 SLAB_MEM_SPREAD|SLAB_PANIC), 2824 NULL); 2825 2826 order = 0; 2827 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2828 if (!dquot_hash) 2829 panic("Cannot create dquot hash table"); 2830 2831 for (i = 0; i < _DQST_DQSTAT_LAST; i++) { 2832 ret = percpu_counter_init(&dqstats.counter[i], 0, GFP_KERNEL); 2833 if (ret) 2834 panic("Cannot create dquot stat counters"); 2835 } 2836 2837 /* Find power-of-two hlist_heads which can fit into allocation */ 2838 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2839 dq_hash_bits = 0; 2840 do { 2841 dq_hash_bits++; 2842 } while (nr_hash >> dq_hash_bits); 2843 dq_hash_bits--; 2844 2845 nr_hash = 1UL << dq_hash_bits; 2846 dq_hash_mask = nr_hash - 1; 2847 for (i = 0; i < nr_hash; i++) 2848 INIT_HLIST_HEAD(dquot_hash + i); 2849 2850 pr_info("VFS: Dquot-cache hash table entries: %ld (order %ld," 2851 " %ld bytes)\n", nr_hash, order, (PAGE_SIZE << order)); 2852 2853 register_shrinker(&dqcache_shrinker); 2854 2855 return 0; 2856 } 2857 module_init(dquot_init); 2858