Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/fs/dquot.c
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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 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE 81 #include <net/netlink.h> 82 #include <net/genetlink.h> 83 #endif 84 85 #include <asm/uaccess.h> 86 87 #define __DQUOT_PARANOIA 88 89 /* 90 * There are two quota SMP locks. dq_list_lock protects all lists with quotas 91 * and quota formats and also dqstats structure containing statistics about the 92 * lists. dq_data_lock protects data from dq_dqb and also mem_dqinfo structures 93 * and also guards consistency of dquot->dq_dqb with inode->i_blocks, i_bytes. 94 * i_blocks and i_bytes updates itself are guarded by i_lock acquired directly 95 * in inode_add_bytes() and inode_sub_bytes(). 96 * 97 * The spinlock ordering is hence: dq_data_lock > dq_list_lock > i_lock 98 * 99 * Note that some things (eg. sb pointer, type, id) doesn't change during 100 * the life of the dquot structure and so needn't to be protected by a lock 101 * 102 * Any operation working on dquots via inode pointers must hold dqptr_sem. If 103 * operation is just reading pointers from inode (or not using them at all) the 104 * read lock is enough. If pointers are altered function must hold write lock 105 * (these locking rules also apply for S_NOQUOTA flag in the inode - note that 106 * for altering the flag i_mutex is also needed). If operation is holding 107 * reference to dquot in other way (e.g. quotactl ops) it must be guarded by 108 * dqonoff_mutex. 109 * This locking assures that: 110 * a) update/access to dquot pointers in inode is serialized 111 * b) everyone is guarded against invalidate_dquots() 112 * 113 * Each dquot has its dq_lock mutex. Locked dquots might not be referenced 114 * from inodes (dquot_alloc_space() and such don't check the dq_lock). 115 * Currently dquot is locked only when it is being read to memory (or space for 116 * it is being allocated) on the first dqget() and when it is being released on 117 * the last dqput(). The allocation and release oparations are serialized by 118 * the dq_lock and by checking the use count in dquot_release(). Write 119 * operations on dquots don't hold dq_lock as they copy data under dq_data_lock 120 * spinlock to internal buffers before writing. 121 * 122 * Lock ordering (including related VFS locks) is the following: 123 * i_mutex > dqonoff_sem > journal_lock > dqptr_sem > dquot->dq_lock > 124 * dqio_mutex 125 * i_mutex on quota files is special (it's below dqio_mutex) 126 */ 127 128 static DEFINE_SPINLOCK(dq_list_lock); 129 DEFINE_SPINLOCK(dq_data_lock); 130 131 static char *quotatypes[] = INITQFNAMES; 132 static struct quota_format_type *quota_formats; /* List of registered formats */ 133 static struct quota_module_name module_names[] = INIT_QUOTA_MODULE_NAMES; 134 135 /* SLAB cache for dquot structures */ 136 static struct kmem_cache *dquot_cachep; 137 138 int register_quota_format(struct quota_format_type *fmt) 139 { 140 spin_lock(&dq_list_lock); 141 fmt->qf_next = quota_formats; 142 quota_formats = fmt; 143 spin_unlock(&dq_list_lock); 144 return 0; 145 } 146 147 void unregister_quota_format(struct quota_format_type *fmt) 148 { 149 struct quota_format_type **actqf; 150 151 spin_lock(&dq_list_lock); 152 for (actqf = "a_formats; *actqf && *actqf != fmt; actqf = &(*actqf)->qf_next); 153 if (*actqf) 154 *actqf = (*actqf)->qf_next; 155 spin_unlock(&dq_list_lock); 156 } 157 158 static struct quota_format_type *find_quota_format(int id) 159 { 160 struct quota_format_type *actqf; 161 162 spin_lock(&dq_list_lock); 163 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next); 164 if (!actqf || !try_module_get(actqf->qf_owner)) { 165 int qm; 166 167 spin_unlock(&dq_list_lock); 168 169 for (qm = 0; module_names[qm].qm_fmt_id && module_names[qm].qm_fmt_id != id; qm++); 170 if (!module_names[qm].qm_fmt_id || request_module(module_names[qm].qm_mod_name)) 171 return NULL; 172 173 spin_lock(&dq_list_lock); 174 for (actqf = quota_formats; actqf && actqf->qf_fmt_id != id; actqf = actqf->qf_next); 175 if (actqf && !try_module_get(actqf->qf_owner)) 176 actqf = NULL; 177 } 178 spin_unlock(&dq_list_lock); 179 return actqf; 180 } 181 182 static void put_quota_format(struct quota_format_type *fmt) 183 { 184 module_put(fmt->qf_owner); 185 } 186 187 /* 188 * Dquot List Management: 189 * The quota code uses three lists for dquot management: the inuse_list, 190 * free_dquots, and dquot_hash[] array. A single dquot structure may be 191 * on all three lists, depending on its current state. 192 * 193 * All dquots are placed to the end of inuse_list when first created, and this 194 * list is used for invalidate operation, which must look at every dquot. 195 * 196 * Unused dquots (dq_count == 0) are added to the free_dquots list when freed, 197 * and this list is searched whenever we need an available dquot. Dquots are 198 * removed from the list as soon as they are used again, and 199 * dqstats.free_dquots gives the number of dquots on the list. When 200 * dquot is invalidated it's completely released from memory. 201 * 202 * Dquots with a specific identity (device, type and id) are placed on 203 * one of the dquot_hash[] hash chains. The provides an efficient search 204 * mechanism to locate a specific dquot. 205 */ 206 207 static LIST_HEAD(inuse_list); 208 static LIST_HEAD(free_dquots); 209 static unsigned int dq_hash_bits, dq_hash_mask; 210 static struct hlist_head *dquot_hash; 211 212 struct dqstats dqstats; 213 214 static void dqput(struct dquot *dquot); 215 216 static inline unsigned int 217 hashfn(const struct super_block *sb, unsigned int id, int type) 218 { 219 unsigned long tmp; 220 221 tmp = (((unsigned long)sb>>L1_CACHE_SHIFT) ^ id) * (MAXQUOTAS - type); 222 return (tmp + (tmp >> dq_hash_bits)) & dq_hash_mask; 223 } 224 225 /* 226 * Following list functions expect dq_list_lock to be held 227 */ 228 static inline void insert_dquot_hash(struct dquot *dquot) 229 { 230 struct hlist_head *head = dquot_hash + hashfn(dquot->dq_sb, dquot->dq_id, dquot->dq_type); 231 hlist_add_head(&dquot->dq_hash, head); 232 } 233 234 static inline void remove_dquot_hash(struct dquot *dquot) 235 { 236 hlist_del_init(&dquot->dq_hash); 237 } 238 239 static inline struct dquot *find_dquot(unsigned int hashent, struct super_block *sb, unsigned int id, int type) 240 { 241 struct hlist_node *node; 242 struct dquot *dquot; 243 244 hlist_for_each (node, dquot_hash+hashent) { 245 dquot = hlist_entry(node, struct dquot, dq_hash); 246 if (dquot->dq_sb == sb && dquot->dq_id == id && dquot->dq_type == type) 247 return dquot; 248 } 249 return NODQUOT; 250 } 251 252 /* Add a dquot to the tail of the free list */ 253 static inline void put_dquot_last(struct dquot *dquot) 254 { 255 list_add_tail(&dquot->dq_free, &free_dquots); 256 dqstats.free_dquots++; 257 } 258 259 static inline void remove_free_dquot(struct dquot *dquot) 260 { 261 if (list_empty(&dquot->dq_free)) 262 return; 263 list_del_init(&dquot->dq_free); 264 dqstats.free_dquots--; 265 } 266 267 static inline void put_inuse(struct dquot *dquot) 268 { 269 /* We add to the back of inuse list so we don't have to restart 270 * when traversing this list and we block */ 271 list_add_tail(&dquot->dq_inuse, &inuse_list); 272 dqstats.allocated_dquots++; 273 } 274 275 static inline void remove_inuse(struct dquot *dquot) 276 { 277 dqstats.allocated_dquots--; 278 list_del(&dquot->dq_inuse); 279 } 280 /* 281 * End of list functions needing dq_list_lock 282 */ 283 284 static void wait_on_dquot(struct dquot *dquot) 285 { 286 mutex_lock(&dquot->dq_lock); 287 mutex_unlock(&dquot->dq_lock); 288 } 289 290 static inline int dquot_dirty(struct dquot *dquot) 291 { 292 return test_bit(DQ_MOD_B, &dquot->dq_flags); 293 } 294 295 static inline int mark_dquot_dirty(struct dquot *dquot) 296 { 297 return dquot->dq_sb->dq_op->mark_dirty(dquot); 298 } 299 300 int dquot_mark_dquot_dirty(struct dquot *dquot) 301 { 302 spin_lock(&dq_list_lock); 303 if (!test_and_set_bit(DQ_MOD_B, &dquot->dq_flags)) 304 list_add(&dquot->dq_dirty, &sb_dqopt(dquot->dq_sb)-> 305 info[dquot->dq_type].dqi_dirty_list); 306 spin_unlock(&dq_list_lock); 307 return 0; 308 } 309 310 /* This function needs dq_list_lock */ 311 static inline int clear_dquot_dirty(struct dquot *dquot) 312 { 313 if (!test_and_clear_bit(DQ_MOD_B, &dquot->dq_flags)) 314 return 0; 315 list_del_init(&dquot->dq_dirty); 316 return 1; 317 } 318 319 void mark_info_dirty(struct super_block *sb, int type) 320 { 321 set_bit(DQF_INFO_DIRTY_B, &sb_dqopt(sb)->info[type].dqi_flags); 322 } 323 EXPORT_SYMBOL(mark_info_dirty); 324 325 /* 326 * Read dquot from disk and alloc space for it 327 */ 328 329 int dquot_acquire(struct dquot *dquot) 330 { 331 int ret = 0, ret2 = 0; 332 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 333 334 mutex_lock(&dquot->dq_lock); 335 mutex_lock(&dqopt->dqio_mutex); 336 if (!test_bit(DQ_READ_B, &dquot->dq_flags)) 337 ret = dqopt->ops[dquot->dq_type]->read_dqblk(dquot); 338 if (ret < 0) 339 goto out_iolock; 340 set_bit(DQ_READ_B, &dquot->dq_flags); 341 /* Instantiate dquot if needed */ 342 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && !dquot->dq_off) { 343 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 344 /* Write the info if needed */ 345 if (info_dirty(&dqopt->info[dquot->dq_type])) 346 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); 347 if (ret < 0) 348 goto out_iolock; 349 if (ret2 < 0) { 350 ret = ret2; 351 goto out_iolock; 352 } 353 } 354 set_bit(DQ_ACTIVE_B, &dquot->dq_flags); 355 out_iolock: 356 mutex_unlock(&dqopt->dqio_mutex); 357 mutex_unlock(&dquot->dq_lock); 358 return ret; 359 } 360 361 /* 362 * Write dquot to disk 363 */ 364 int dquot_commit(struct dquot *dquot) 365 { 366 int ret = 0, ret2 = 0; 367 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 368 369 mutex_lock(&dqopt->dqio_mutex); 370 spin_lock(&dq_list_lock); 371 if (!clear_dquot_dirty(dquot)) { 372 spin_unlock(&dq_list_lock); 373 goto out_sem; 374 } 375 spin_unlock(&dq_list_lock); 376 /* Inactive dquot can be only if there was error during read/init 377 * => we have better not writing it */ 378 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 379 ret = dqopt->ops[dquot->dq_type]->commit_dqblk(dquot); 380 if (info_dirty(&dqopt->info[dquot->dq_type])) 381 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); 382 if (ret >= 0) 383 ret = ret2; 384 } 385 out_sem: 386 mutex_unlock(&dqopt->dqio_mutex); 387 return ret; 388 } 389 390 /* 391 * Release dquot 392 */ 393 int dquot_release(struct dquot *dquot) 394 { 395 int ret = 0, ret2 = 0; 396 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb); 397 398 mutex_lock(&dquot->dq_lock); 399 /* Check whether we are not racing with some other dqget() */ 400 if (atomic_read(&dquot->dq_count) > 1) 401 goto out_dqlock; 402 mutex_lock(&dqopt->dqio_mutex); 403 if (dqopt->ops[dquot->dq_type]->release_dqblk) { 404 ret = dqopt->ops[dquot->dq_type]->release_dqblk(dquot); 405 /* Write the info */ 406 if (info_dirty(&dqopt->info[dquot->dq_type])) 407 ret2 = dqopt->ops[dquot->dq_type]->write_file_info(dquot->dq_sb, dquot->dq_type); 408 if (ret >= 0) 409 ret = ret2; 410 } 411 clear_bit(DQ_ACTIVE_B, &dquot->dq_flags); 412 mutex_unlock(&dqopt->dqio_mutex); 413 out_dqlock: 414 mutex_unlock(&dquot->dq_lock); 415 return ret; 416 } 417 418 /* Invalidate all dquots on the list. Note that this function is called after 419 * quota is disabled and pointers from inodes removed so there cannot be new 420 * quota users. There can still be some users of quotas due to inodes being 421 * just deleted or pruned by prune_icache() (those are not attached to any 422 * list). We have to wait for such users. 423 */ 424 static void invalidate_dquots(struct super_block *sb, int type) 425 { 426 struct dquot *dquot, *tmp; 427 428 restart: 429 spin_lock(&dq_list_lock); 430 list_for_each_entry_safe(dquot, tmp, &inuse_list, dq_inuse) { 431 if (dquot->dq_sb != sb) 432 continue; 433 if (dquot->dq_type != type) 434 continue; 435 /* Wait for dquot users */ 436 if (atomic_read(&dquot->dq_count)) { 437 DEFINE_WAIT(wait); 438 439 atomic_inc(&dquot->dq_count); 440 prepare_to_wait(&dquot->dq_wait_unused, &wait, 441 TASK_UNINTERRUPTIBLE); 442 spin_unlock(&dq_list_lock); 443 /* Once dqput() wakes us up, we know it's time to free 444 * the dquot. 445 * IMPORTANT: we rely on the fact that there is always 446 * at most one process waiting for dquot to free. 447 * Otherwise dq_count would be > 1 and we would never 448 * wake up. 449 */ 450 if (atomic_read(&dquot->dq_count) > 1) 451 schedule(); 452 finish_wait(&dquot->dq_wait_unused, &wait); 453 dqput(dquot); 454 /* At this moment dquot() need not exist (it could be 455 * reclaimed by prune_dqcache(). Hence we must 456 * restart. */ 457 goto restart; 458 } 459 /* 460 * Quota now has no users and it has been written on last 461 * dqput() 462 */ 463 remove_dquot_hash(dquot); 464 remove_free_dquot(dquot); 465 remove_inuse(dquot); 466 kmem_cache_free(dquot_cachep, dquot); 467 } 468 spin_unlock(&dq_list_lock); 469 } 470 471 int vfs_quota_sync(struct super_block *sb, int type) 472 { 473 struct list_head *dirty; 474 struct dquot *dquot; 475 struct quota_info *dqopt = sb_dqopt(sb); 476 int cnt; 477 478 mutex_lock(&dqopt->dqonoff_mutex); 479 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 480 if (type != -1 && cnt != type) 481 continue; 482 if (!sb_has_quota_enabled(sb, cnt)) 483 continue; 484 spin_lock(&dq_list_lock); 485 dirty = &dqopt->info[cnt].dqi_dirty_list; 486 while (!list_empty(dirty)) { 487 dquot = list_first_entry(dirty, struct dquot, dq_dirty); 488 /* Dirty and inactive can be only bad dquot... */ 489 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 490 clear_dquot_dirty(dquot); 491 continue; 492 } 493 /* Now we have active dquot from which someone is 494 * holding reference so we can safely just increase 495 * use count */ 496 atomic_inc(&dquot->dq_count); 497 dqstats.lookups++; 498 spin_unlock(&dq_list_lock); 499 sb->dq_op->write_dquot(dquot); 500 dqput(dquot); 501 spin_lock(&dq_list_lock); 502 } 503 spin_unlock(&dq_list_lock); 504 } 505 506 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 507 if ((cnt == type || type == -1) && sb_has_quota_enabled(sb, cnt) 508 && info_dirty(&dqopt->info[cnt])) 509 sb->dq_op->write_info(sb, cnt); 510 spin_lock(&dq_list_lock); 511 dqstats.syncs++; 512 spin_unlock(&dq_list_lock); 513 mutex_unlock(&dqopt->dqonoff_mutex); 514 515 return 0; 516 } 517 518 /* Free unused dquots from cache */ 519 static void prune_dqcache(int count) 520 { 521 struct list_head *head; 522 struct dquot *dquot; 523 524 head = free_dquots.prev; 525 while (head != &free_dquots && count) { 526 dquot = list_entry(head, struct dquot, dq_free); 527 remove_dquot_hash(dquot); 528 remove_free_dquot(dquot); 529 remove_inuse(dquot); 530 kmem_cache_free(dquot_cachep, dquot); 531 count--; 532 head = free_dquots.prev; 533 } 534 } 535 536 /* 537 * This is called from kswapd when we think we need some 538 * more memory 539 */ 540 541 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask) 542 { 543 if (nr) { 544 spin_lock(&dq_list_lock); 545 prune_dqcache(nr); 546 spin_unlock(&dq_list_lock); 547 } 548 return (dqstats.free_dquots / 100) * sysctl_vfs_cache_pressure; 549 } 550 551 static struct shrinker dqcache_shrinker = { 552 .shrink = shrink_dqcache_memory, 553 .seeks = DEFAULT_SEEKS, 554 }; 555 556 /* 557 * Put reference to dquot 558 * NOTE: If you change this function please check whether dqput_blocks() works right... 559 * MUST be called with either dqptr_sem or dqonoff_mutex held 560 */ 561 static void dqput(struct dquot *dquot) 562 { 563 int ret; 564 565 if (!dquot) 566 return; 567 #ifdef __DQUOT_PARANOIA 568 if (!atomic_read(&dquot->dq_count)) { 569 printk("VFS: dqput: trying to free free dquot\n"); 570 printk("VFS: device %s, dquot of %s %d\n", 571 dquot->dq_sb->s_id, 572 quotatypes[dquot->dq_type], 573 dquot->dq_id); 574 BUG(); 575 } 576 #endif 577 578 spin_lock(&dq_list_lock); 579 dqstats.drops++; 580 spin_unlock(&dq_list_lock); 581 we_slept: 582 spin_lock(&dq_list_lock); 583 if (atomic_read(&dquot->dq_count) > 1) { 584 /* We have more than one user... nothing to do */ 585 atomic_dec(&dquot->dq_count); 586 /* Releasing dquot during quotaoff phase? */ 587 if (!sb_has_quota_enabled(dquot->dq_sb, dquot->dq_type) && 588 atomic_read(&dquot->dq_count) == 1) 589 wake_up(&dquot->dq_wait_unused); 590 spin_unlock(&dq_list_lock); 591 return; 592 } 593 /* Need to release dquot? */ 594 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && dquot_dirty(dquot)) { 595 spin_unlock(&dq_list_lock); 596 /* Commit dquot before releasing */ 597 ret = dquot->dq_sb->dq_op->write_dquot(dquot); 598 if (ret < 0) { 599 printk(KERN_ERR "VFS: cannot write quota structure on " 600 "device %s (error %d). Quota may get out of " 601 "sync!\n", dquot->dq_sb->s_id, ret); 602 /* 603 * We clear dirty bit anyway, so that we avoid 604 * infinite loop here 605 */ 606 spin_lock(&dq_list_lock); 607 clear_dquot_dirty(dquot); 608 spin_unlock(&dq_list_lock); 609 } 610 goto we_slept; 611 } 612 /* Clear flag in case dquot was inactive (something bad happened) */ 613 clear_dquot_dirty(dquot); 614 if (test_bit(DQ_ACTIVE_B, &dquot->dq_flags)) { 615 spin_unlock(&dq_list_lock); 616 dquot->dq_sb->dq_op->release_dquot(dquot); 617 goto we_slept; 618 } 619 atomic_dec(&dquot->dq_count); 620 #ifdef __DQUOT_PARANOIA 621 /* sanity check */ 622 BUG_ON(!list_empty(&dquot->dq_free)); 623 #endif 624 put_dquot_last(dquot); 625 spin_unlock(&dq_list_lock); 626 } 627 628 static struct dquot *get_empty_dquot(struct super_block *sb, int type) 629 { 630 struct dquot *dquot; 631 632 dquot = kmem_cache_zalloc(dquot_cachep, GFP_NOFS); 633 if(!dquot) 634 return NODQUOT; 635 636 mutex_init(&dquot->dq_lock); 637 INIT_LIST_HEAD(&dquot->dq_free); 638 INIT_LIST_HEAD(&dquot->dq_inuse); 639 INIT_HLIST_NODE(&dquot->dq_hash); 640 INIT_LIST_HEAD(&dquot->dq_dirty); 641 init_waitqueue_head(&dquot->dq_wait_unused); 642 dquot->dq_sb = sb; 643 dquot->dq_type = type; 644 atomic_set(&dquot->dq_count, 1); 645 646 return dquot; 647 } 648 649 /* 650 * Get reference to dquot 651 * MUST be called with either dqptr_sem or dqonoff_mutex held 652 */ 653 static struct dquot *dqget(struct super_block *sb, unsigned int id, int type) 654 { 655 unsigned int hashent = hashfn(sb, id, type); 656 struct dquot *dquot, *empty = NODQUOT; 657 658 if (!sb_has_quota_enabled(sb, type)) 659 return NODQUOT; 660 we_slept: 661 spin_lock(&dq_list_lock); 662 if ((dquot = find_dquot(hashent, sb, id, type)) == NODQUOT) { 663 if (empty == NODQUOT) { 664 spin_unlock(&dq_list_lock); 665 if ((empty = get_empty_dquot(sb, type)) == NODQUOT) 666 schedule(); /* Try to wait for a moment... */ 667 goto we_slept; 668 } 669 dquot = empty; 670 dquot->dq_id = id; 671 /* all dquots go on the inuse_list */ 672 put_inuse(dquot); 673 /* hash it first so it can be found */ 674 insert_dquot_hash(dquot); 675 dqstats.lookups++; 676 spin_unlock(&dq_list_lock); 677 } else { 678 if (!atomic_read(&dquot->dq_count)) 679 remove_free_dquot(dquot); 680 atomic_inc(&dquot->dq_count); 681 dqstats.cache_hits++; 682 dqstats.lookups++; 683 spin_unlock(&dq_list_lock); 684 if (empty) 685 kmem_cache_free(dquot_cachep, empty); 686 } 687 /* Wait for dq_lock - after this we know that either dquot_release() is already 688 * finished or it will be canceled due to dq_count > 1 test */ 689 wait_on_dquot(dquot); 690 /* Read the dquot and instantiate it (everything done only if needed) */ 691 if (!test_bit(DQ_ACTIVE_B, &dquot->dq_flags) && sb->dq_op->acquire_dquot(dquot) < 0) { 692 dqput(dquot); 693 return NODQUOT; 694 } 695 #ifdef __DQUOT_PARANOIA 696 BUG_ON(!dquot->dq_sb); /* Has somebody invalidated entry under us? */ 697 #endif 698 699 return dquot; 700 } 701 702 static int dqinit_needed(struct inode *inode, int type) 703 { 704 int cnt; 705 706 if (IS_NOQUOTA(inode)) 707 return 0; 708 if (type != -1) 709 return inode->i_dquot[type] == NODQUOT; 710 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 711 if (inode->i_dquot[cnt] == NODQUOT) 712 return 1; 713 return 0; 714 } 715 716 /* This routine is guarded by dqonoff_mutex mutex */ 717 static void add_dquot_ref(struct super_block *sb, int type) 718 { 719 struct inode *inode, *old_inode = NULL; 720 721 spin_lock(&inode_lock); 722 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 723 if (!atomic_read(&inode->i_writecount)) 724 continue; 725 if (!dqinit_needed(inode, type)) 726 continue; 727 if (inode->i_state & (I_FREEING|I_WILL_FREE)) 728 continue; 729 730 __iget(inode); 731 spin_unlock(&inode_lock); 732 733 iput(old_inode); 734 sb->dq_op->initialize(inode, type); 735 /* We hold a reference to 'inode' so it couldn't have been 736 * removed from s_inodes list while we dropped the inode_lock. 737 * We cannot iput the inode now as we can be holding the last 738 * reference and we cannot iput it under inode_lock. So we 739 * keep the reference and iput it later. */ 740 old_inode = inode; 741 spin_lock(&inode_lock); 742 } 743 spin_unlock(&inode_lock); 744 iput(old_inode); 745 } 746 747 /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */ 748 static inline int dqput_blocks(struct dquot *dquot) 749 { 750 if (atomic_read(&dquot->dq_count) <= 1) 751 return 1; 752 return 0; 753 } 754 755 /* Remove references to dquots from inode - add dquot to list for freeing if needed */ 756 /* We can't race with anybody because we hold dqptr_sem for writing... */ 757 static int remove_inode_dquot_ref(struct inode *inode, int type, 758 struct list_head *tofree_head) 759 { 760 struct dquot *dquot = inode->i_dquot[type]; 761 762 inode->i_dquot[type] = NODQUOT; 763 if (dquot != NODQUOT) { 764 if (dqput_blocks(dquot)) { 765 #ifdef __DQUOT_PARANOIA 766 if (atomic_read(&dquot->dq_count) != 1) 767 printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count)); 768 #endif 769 spin_lock(&dq_list_lock); 770 list_add(&dquot->dq_free, tofree_head); /* As dquot must have currently users it can't be on the free list... */ 771 spin_unlock(&dq_list_lock); 772 return 1; 773 } 774 else 775 dqput(dquot); /* We have guaranteed we won't block */ 776 } 777 return 0; 778 } 779 780 /* Free list of dquots - called from inode.c */ 781 /* dquots are removed from inodes, no new references can be got so we are the only ones holding reference */ 782 static void put_dquot_list(struct list_head *tofree_head) 783 { 784 struct list_head *act_head; 785 struct dquot *dquot; 786 787 act_head = tofree_head->next; 788 /* So now we have dquots on the list... Just free them */ 789 while (act_head != tofree_head) { 790 dquot = list_entry(act_head, struct dquot, dq_free); 791 act_head = act_head->next; 792 list_del_init(&dquot->dq_free); /* Remove dquot from the list so we won't have problems... */ 793 dqput(dquot); 794 } 795 } 796 797 static void remove_dquot_ref(struct super_block *sb, int type, 798 struct list_head *tofree_head) 799 { 800 struct inode *inode; 801 802 spin_lock(&inode_lock); 803 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { 804 if (!IS_NOQUOTA(inode)) 805 remove_inode_dquot_ref(inode, type, tofree_head); 806 } 807 spin_unlock(&inode_lock); 808 } 809 810 /* Gather all references from inodes and drop them */ 811 static void drop_dquot_ref(struct super_block *sb, int type) 812 { 813 LIST_HEAD(tofree_head); 814 815 if (sb->dq_op) { 816 down_write(&sb_dqopt(sb)->dqptr_sem); 817 remove_dquot_ref(sb, type, &tofree_head); 818 up_write(&sb_dqopt(sb)->dqptr_sem); 819 put_dquot_list(&tofree_head); 820 } 821 } 822 823 static inline void dquot_incr_inodes(struct dquot *dquot, unsigned long number) 824 { 825 dquot->dq_dqb.dqb_curinodes += number; 826 } 827 828 static inline void dquot_incr_space(struct dquot *dquot, qsize_t number) 829 { 830 dquot->dq_dqb.dqb_curspace += number; 831 } 832 833 static inline void dquot_decr_inodes(struct dquot *dquot, unsigned long number) 834 { 835 if (dquot->dq_dqb.dqb_curinodes > number) 836 dquot->dq_dqb.dqb_curinodes -= number; 837 else 838 dquot->dq_dqb.dqb_curinodes = 0; 839 if (dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 840 dquot->dq_dqb.dqb_itime = (time_t) 0; 841 clear_bit(DQ_INODES_B, &dquot->dq_flags); 842 } 843 844 static inline void dquot_decr_space(struct dquot *dquot, qsize_t number) 845 { 846 if (dquot->dq_dqb.dqb_curspace > number) 847 dquot->dq_dqb.dqb_curspace -= number; 848 else 849 dquot->dq_dqb.dqb_curspace = 0; 850 if (toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit) 851 dquot->dq_dqb.dqb_btime = (time_t) 0; 852 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 853 } 854 855 static int warning_issued(struct dquot *dquot, const int warntype) 856 { 857 int flag = (warntype == QUOTA_NL_BHARDWARN || 858 warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B : 859 ((warntype == QUOTA_NL_IHARDWARN || 860 warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0); 861 862 if (!flag) 863 return 0; 864 return test_and_set_bit(flag, &dquot->dq_flags); 865 } 866 867 #ifdef CONFIG_PRINT_QUOTA_WARNING 868 static int flag_print_warnings = 1; 869 870 static inline int need_print_warning(struct dquot *dquot) 871 { 872 if (!flag_print_warnings) 873 return 0; 874 875 switch (dquot->dq_type) { 876 case USRQUOTA: 877 return current->fsuid == dquot->dq_id; 878 case GRPQUOTA: 879 return in_group_p(dquot->dq_id); 880 } 881 return 0; 882 } 883 884 /* Print warning to user which exceeded quota */ 885 static void print_warning(struct dquot *dquot, const int warntype) 886 { 887 char *msg = NULL; 888 struct tty_struct *tty; 889 890 if (warntype == QUOTA_NL_IHARDBELOW || 891 warntype == QUOTA_NL_ISOFTBELOW || 892 warntype == QUOTA_NL_BHARDBELOW || 893 warntype == QUOTA_NL_BSOFTBELOW || !need_print_warning(dquot)) 894 return; 895 896 tty = get_current_tty(); 897 if (!tty) 898 return; 899 tty_write_message(tty, dquot->dq_sb->s_id); 900 if (warntype == QUOTA_NL_ISOFTWARN || warntype == QUOTA_NL_BSOFTWARN) 901 tty_write_message(tty, ": warning, "); 902 else 903 tty_write_message(tty, ": write failed, "); 904 tty_write_message(tty, quotatypes[dquot->dq_type]); 905 switch (warntype) { 906 case QUOTA_NL_IHARDWARN: 907 msg = " file limit reached.\r\n"; 908 break; 909 case QUOTA_NL_ISOFTLONGWARN: 910 msg = " file quota exceeded too long.\r\n"; 911 break; 912 case QUOTA_NL_ISOFTWARN: 913 msg = " file quota exceeded.\r\n"; 914 break; 915 case QUOTA_NL_BHARDWARN: 916 msg = " block limit reached.\r\n"; 917 break; 918 case QUOTA_NL_BSOFTLONGWARN: 919 msg = " block quota exceeded too long.\r\n"; 920 break; 921 case QUOTA_NL_BSOFTWARN: 922 msg = " block quota exceeded.\r\n"; 923 break; 924 } 925 tty_write_message(tty, msg); 926 tty_kref_put(tty); 927 } 928 #endif 929 930 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE 931 932 /* Netlink family structure for quota */ 933 static struct genl_family quota_genl_family = { 934 .id = GENL_ID_GENERATE, 935 .hdrsize = 0, 936 .name = "VFS_DQUOT", 937 .version = 1, 938 .maxattr = QUOTA_NL_A_MAX, 939 }; 940 941 /* Send warning to userspace about user which exceeded quota */ 942 static void send_warning(const struct dquot *dquot, const char warntype) 943 { 944 static atomic_t seq; 945 struct sk_buff *skb; 946 void *msg_head; 947 int ret; 948 int msg_size = 4 * nla_total_size(sizeof(u32)) + 949 2 * nla_total_size(sizeof(u64)); 950 951 /* We have to allocate using GFP_NOFS as we are called from a 952 * filesystem performing write and thus further recursion into 953 * the fs to free some data could cause deadlocks. */ 954 skb = genlmsg_new(msg_size, GFP_NOFS); 955 if (!skb) { 956 printk(KERN_ERR 957 "VFS: Not enough memory to send quota warning.\n"); 958 return; 959 } 960 msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq), 961 "a_genl_family, 0, QUOTA_NL_C_WARNING); 962 if (!msg_head) { 963 printk(KERN_ERR 964 "VFS: Cannot store netlink header in quota warning.\n"); 965 goto err_out; 966 } 967 ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, dquot->dq_type); 968 if (ret) 969 goto attr_err_out; 970 ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID, dquot->dq_id); 971 if (ret) 972 goto attr_err_out; 973 ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype); 974 if (ret) 975 goto attr_err_out; 976 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, 977 MAJOR(dquot->dq_sb->s_dev)); 978 if (ret) 979 goto attr_err_out; 980 ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, 981 MINOR(dquot->dq_sb->s_dev)); 982 if (ret) 983 goto attr_err_out; 984 ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID, current->user->uid); 985 if (ret) 986 goto attr_err_out; 987 genlmsg_end(skb, msg_head); 988 989 ret = genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS); 990 if (ret < 0 && ret != -ESRCH) 991 printk(KERN_ERR 992 "VFS: Failed to send notification message: %d\n", ret); 993 return; 994 attr_err_out: 995 printk(KERN_ERR "VFS: Not enough space to compose quota message!\n"); 996 err_out: 997 kfree_skb(skb); 998 } 999 #endif 1000 1001 static inline void flush_warnings(struct dquot * const *dquots, char *warntype) 1002 { 1003 int i; 1004 1005 for (i = 0; i < MAXQUOTAS; i++) 1006 if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN && 1007 !warning_issued(dquots[i], warntype[i])) { 1008 #ifdef CONFIG_PRINT_QUOTA_WARNING 1009 print_warning(dquots[i], warntype[i]); 1010 #endif 1011 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE 1012 send_warning(dquots[i], warntype[i]); 1013 #endif 1014 } 1015 } 1016 1017 static inline char ignore_hardlimit(struct dquot *dquot) 1018 { 1019 struct mem_dqinfo *info = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1020 1021 return capable(CAP_SYS_RESOURCE) && 1022 (info->dqi_format->qf_fmt_id != QFMT_VFS_OLD || !(info->dqi_flags & V1_DQF_RSQUASH)); 1023 } 1024 1025 /* needs dq_data_lock */ 1026 static int check_idq(struct dquot *dquot, ulong inodes, char *warntype) 1027 { 1028 *warntype = QUOTA_NL_NOWARN; 1029 if (inodes <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1030 return QUOTA_OK; 1031 1032 if (dquot->dq_dqb.dqb_ihardlimit && 1033 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_ihardlimit && 1034 !ignore_hardlimit(dquot)) { 1035 *warntype = QUOTA_NL_IHARDWARN; 1036 return NO_QUOTA; 1037 } 1038 1039 if (dquot->dq_dqb.dqb_isoftlimit && 1040 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && 1041 dquot->dq_dqb.dqb_itime && get_seconds() >= dquot->dq_dqb.dqb_itime && 1042 !ignore_hardlimit(dquot)) { 1043 *warntype = QUOTA_NL_ISOFTLONGWARN; 1044 return NO_QUOTA; 1045 } 1046 1047 if (dquot->dq_dqb.dqb_isoftlimit && 1048 (dquot->dq_dqb.dqb_curinodes + inodes) > dquot->dq_dqb.dqb_isoftlimit && 1049 dquot->dq_dqb.dqb_itime == 0) { 1050 *warntype = QUOTA_NL_ISOFTWARN; 1051 dquot->dq_dqb.dqb_itime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_igrace; 1052 } 1053 1054 return QUOTA_OK; 1055 } 1056 1057 /* needs dq_data_lock */ 1058 static int check_bdq(struct dquot *dquot, qsize_t space, int prealloc, char *warntype) 1059 { 1060 *warntype = QUOTA_NL_NOWARN; 1061 if (space <= 0 || test_bit(DQ_FAKE_B, &dquot->dq_flags)) 1062 return QUOTA_OK; 1063 1064 if (dquot->dq_dqb.dqb_bhardlimit && 1065 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bhardlimit && 1066 !ignore_hardlimit(dquot)) { 1067 if (!prealloc) 1068 *warntype = QUOTA_NL_BHARDWARN; 1069 return NO_QUOTA; 1070 } 1071 1072 if (dquot->dq_dqb.dqb_bsoftlimit && 1073 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit && 1074 dquot->dq_dqb.dqb_btime && get_seconds() >= dquot->dq_dqb.dqb_btime && 1075 !ignore_hardlimit(dquot)) { 1076 if (!prealloc) 1077 *warntype = QUOTA_NL_BSOFTLONGWARN; 1078 return NO_QUOTA; 1079 } 1080 1081 if (dquot->dq_dqb.dqb_bsoftlimit && 1082 toqb(dquot->dq_dqb.dqb_curspace + space) > dquot->dq_dqb.dqb_bsoftlimit && 1083 dquot->dq_dqb.dqb_btime == 0) { 1084 if (!prealloc) { 1085 *warntype = QUOTA_NL_BSOFTWARN; 1086 dquot->dq_dqb.dqb_btime = get_seconds() + sb_dqopt(dquot->dq_sb)->info[dquot->dq_type].dqi_bgrace; 1087 } 1088 else 1089 /* 1090 * We don't allow preallocation to exceed softlimit so exceeding will 1091 * be always printed 1092 */ 1093 return NO_QUOTA; 1094 } 1095 1096 return QUOTA_OK; 1097 } 1098 1099 static int info_idq_free(struct dquot *dquot, ulong inodes) 1100 { 1101 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1102 dquot->dq_dqb.dqb_curinodes <= dquot->dq_dqb.dqb_isoftlimit) 1103 return QUOTA_NL_NOWARN; 1104 1105 if (dquot->dq_dqb.dqb_curinodes - inodes <= dquot->dq_dqb.dqb_isoftlimit) 1106 return QUOTA_NL_ISOFTBELOW; 1107 if (dquot->dq_dqb.dqb_curinodes >= dquot->dq_dqb.dqb_ihardlimit && 1108 dquot->dq_dqb.dqb_curinodes - inodes < dquot->dq_dqb.dqb_ihardlimit) 1109 return QUOTA_NL_IHARDBELOW; 1110 return QUOTA_NL_NOWARN; 1111 } 1112 1113 static int info_bdq_free(struct dquot *dquot, qsize_t space) 1114 { 1115 if (test_bit(DQ_FAKE_B, &dquot->dq_flags) || 1116 toqb(dquot->dq_dqb.dqb_curspace) <= dquot->dq_dqb.dqb_bsoftlimit) 1117 return QUOTA_NL_NOWARN; 1118 1119 if (toqb(dquot->dq_dqb.dqb_curspace - space) <= 1120 dquot->dq_dqb.dqb_bsoftlimit) 1121 return QUOTA_NL_BSOFTBELOW; 1122 if (toqb(dquot->dq_dqb.dqb_curspace) >= dquot->dq_dqb.dqb_bhardlimit && 1123 toqb(dquot->dq_dqb.dqb_curspace - space) < 1124 dquot->dq_dqb.dqb_bhardlimit) 1125 return QUOTA_NL_BHARDBELOW; 1126 return QUOTA_NL_NOWARN; 1127 } 1128 /* 1129 * Initialize quota pointers in inode 1130 * Transaction must be started at entry 1131 */ 1132 int dquot_initialize(struct inode *inode, int type) 1133 { 1134 unsigned int id = 0; 1135 int cnt, ret = 0; 1136 1137 /* First test before acquiring mutex - solves deadlocks when we 1138 * re-enter the quota code and are already holding the mutex */ 1139 if (IS_NOQUOTA(inode)) 1140 return 0; 1141 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1142 /* Having dqptr_sem we know NOQUOTA flags can't be altered... */ 1143 if (IS_NOQUOTA(inode)) 1144 goto out_err; 1145 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1146 if (type != -1 && cnt != type) 1147 continue; 1148 if (inode->i_dquot[cnt] == NODQUOT) { 1149 switch (cnt) { 1150 case USRQUOTA: 1151 id = inode->i_uid; 1152 break; 1153 case GRPQUOTA: 1154 id = inode->i_gid; 1155 break; 1156 } 1157 inode->i_dquot[cnt] = dqget(inode->i_sb, id, cnt); 1158 } 1159 } 1160 out_err: 1161 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1162 return ret; 1163 } 1164 1165 /* 1166 * Release all quotas referenced by inode 1167 * Transaction must be started at an entry 1168 */ 1169 int dquot_drop(struct inode *inode) 1170 { 1171 int cnt; 1172 1173 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1174 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1175 if (inode->i_dquot[cnt] != NODQUOT) { 1176 dqput(inode->i_dquot[cnt]); 1177 inode->i_dquot[cnt] = NODQUOT; 1178 } 1179 } 1180 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1181 return 0; 1182 } 1183 1184 /* Wrapper to remove references to quota structures from inode */ 1185 void vfs_dq_drop(struct inode *inode) 1186 { 1187 /* Here we can get arbitrary inode from clear_inode() so we have 1188 * to be careful. OTOH we don't need locking as quota operations 1189 * are allowed to change only at mount time */ 1190 if (!IS_NOQUOTA(inode) && inode->i_sb && inode->i_sb->dq_op 1191 && inode->i_sb->dq_op->drop) { 1192 int cnt; 1193 /* Test before calling to rule out calls from proc and such 1194 * where we are not allowed to block. Note that this is 1195 * actually reliable test even without the lock - the caller 1196 * must assure that nobody can come after the DQUOT_DROP and 1197 * add quota pointers back anyway */ 1198 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1199 if (inode->i_dquot[cnt] != NODQUOT) 1200 break; 1201 if (cnt < MAXQUOTAS) 1202 inode->i_sb->dq_op->drop(inode); 1203 } 1204 } 1205 1206 /* 1207 * Following four functions update i_blocks+i_bytes fields and 1208 * quota information (together with appropriate checks) 1209 * NOTE: We absolutely rely on the fact that caller dirties 1210 * the inode (usually macros in quotaops.h care about this) and 1211 * holds a handle for the current transaction so that dquot write and 1212 * inode write go into the same transaction. 1213 */ 1214 1215 /* 1216 * This operation can block, but only after everything is updated 1217 */ 1218 int dquot_alloc_space(struct inode *inode, qsize_t number, int warn) 1219 { 1220 int cnt, ret = NO_QUOTA; 1221 char warntype[MAXQUOTAS]; 1222 1223 /* First test before acquiring mutex - solves deadlocks when we 1224 * re-enter the quota code and are already holding the mutex */ 1225 if (IS_NOQUOTA(inode)) { 1226 out_add: 1227 inode_add_bytes(inode, number); 1228 return QUOTA_OK; 1229 } 1230 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1231 warntype[cnt] = QUOTA_NL_NOWARN; 1232 1233 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1234 if (IS_NOQUOTA(inode)) { /* Now we can do reliable test... */ 1235 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1236 goto out_add; 1237 } 1238 spin_lock(&dq_data_lock); 1239 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1240 if (inode->i_dquot[cnt] == NODQUOT) 1241 continue; 1242 if (check_bdq(inode->i_dquot[cnt], number, warn, warntype+cnt) == NO_QUOTA) 1243 goto warn_put_all; 1244 } 1245 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1246 if (inode->i_dquot[cnt] == NODQUOT) 1247 continue; 1248 dquot_incr_space(inode->i_dquot[cnt], number); 1249 } 1250 inode_add_bytes(inode, number); 1251 ret = QUOTA_OK; 1252 warn_put_all: 1253 spin_unlock(&dq_data_lock); 1254 if (ret == QUOTA_OK) 1255 /* Dirtify all the dquots - this can block when journalling */ 1256 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1257 if (inode->i_dquot[cnt]) 1258 mark_dquot_dirty(inode->i_dquot[cnt]); 1259 flush_warnings(inode->i_dquot, warntype); 1260 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1261 return ret; 1262 } 1263 1264 /* 1265 * This operation can block, but only after everything is updated 1266 */ 1267 int dquot_alloc_inode(const struct inode *inode, unsigned long number) 1268 { 1269 int cnt, ret = NO_QUOTA; 1270 char warntype[MAXQUOTAS]; 1271 1272 /* First test before acquiring mutex - solves deadlocks when we 1273 * re-enter the quota code and are already holding the mutex */ 1274 if (IS_NOQUOTA(inode)) 1275 return QUOTA_OK; 1276 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1277 warntype[cnt] = QUOTA_NL_NOWARN; 1278 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1279 if (IS_NOQUOTA(inode)) { 1280 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1281 return QUOTA_OK; 1282 } 1283 spin_lock(&dq_data_lock); 1284 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1285 if (inode->i_dquot[cnt] == NODQUOT) 1286 continue; 1287 if (check_idq(inode->i_dquot[cnt], number, warntype+cnt) == NO_QUOTA) 1288 goto warn_put_all; 1289 } 1290 1291 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1292 if (inode->i_dquot[cnt] == NODQUOT) 1293 continue; 1294 dquot_incr_inodes(inode->i_dquot[cnt], number); 1295 } 1296 ret = QUOTA_OK; 1297 warn_put_all: 1298 spin_unlock(&dq_data_lock); 1299 if (ret == QUOTA_OK) 1300 /* Dirtify all the dquots - this can block when journalling */ 1301 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1302 if (inode->i_dquot[cnt]) 1303 mark_dquot_dirty(inode->i_dquot[cnt]); 1304 flush_warnings(inode->i_dquot, warntype); 1305 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1306 return ret; 1307 } 1308 1309 /* 1310 * This operation can block, but only after everything is updated 1311 */ 1312 int dquot_free_space(struct inode *inode, qsize_t number) 1313 { 1314 unsigned int cnt; 1315 char warntype[MAXQUOTAS]; 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 (IS_NOQUOTA(inode)) { 1320 out_sub: 1321 inode_sub_bytes(inode, number); 1322 return QUOTA_OK; 1323 } 1324 1325 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1326 /* Now recheck reliably when holding dqptr_sem */ 1327 if (IS_NOQUOTA(inode)) { 1328 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1329 goto out_sub; 1330 } 1331 spin_lock(&dq_data_lock); 1332 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1333 if (inode->i_dquot[cnt] == NODQUOT) 1334 continue; 1335 warntype[cnt] = info_bdq_free(inode->i_dquot[cnt], number); 1336 dquot_decr_space(inode->i_dquot[cnt], number); 1337 } 1338 inode_sub_bytes(inode, number); 1339 spin_unlock(&dq_data_lock); 1340 /* Dirtify all the dquots - this can block when journalling */ 1341 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1342 if (inode->i_dquot[cnt]) 1343 mark_dquot_dirty(inode->i_dquot[cnt]); 1344 flush_warnings(inode->i_dquot, warntype); 1345 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1346 return QUOTA_OK; 1347 } 1348 1349 /* 1350 * This operation can block, but only after everything is updated 1351 */ 1352 int dquot_free_inode(const struct inode *inode, unsigned long number) 1353 { 1354 unsigned int cnt; 1355 char warntype[MAXQUOTAS]; 1356 1357 /* First test before acquiring mutex - solves deadlocks when we 1358 * re-enter the quota code and are already holding the mutex */ 1359 if (IS_NOQUOTA(inode)) 1360 return QUOTA_OK; 1361 1362 down_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1363 /* Now recheck reliably when holding dqptr_sem */ 1364 if (IS_NOQUOTA(inode)) { 1365 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1366 return QUOTA_OK; 1367 } 1368 spin_lock(&dq_data_lock); 1369 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1370 if (inode->i_dquot[cnt] == NODQUOT) 1371 continue; 1372 warntype[cnt] = info_idq_free(inode->i_dquot[cnt], number); 1373 dquot_decr_inodes(inode->i_dquot[cnt], number); 1374 } 1375 spin_unlock(&dq_data_lock); 1376 /* Dirtify all the dquots - this can block when journalling */ 1377 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1378 if (inode->i_dquot[cnt]) 1379 mark_dquot_dirty(inode->i_dquot[cnt]); 1380 flush_warnings(inode->i_dquot, warntype); 1381 up_read(&sb_dqopt(inode->i_sb)->dqptr_sem); 1382 return QUOTA_OK; 1383 } 1384 1385 /* 1386 * Transfer the number of inode and blocks from one diskquota to an other. 1387 * 1388 * This operation can block, but only after everything is updated 1389 * A transaction must be started when entering this function. 1390 */ 1391 int dquot_transfer(struct inode *inode, struct iattr *iattr) 1392 { 1393 qsize_t space; 1394 struct dquot *transfer_from[MAXQUOTAS]; 1395 struct dquot *transfer_to[MAXQUOTAS]; 1396 int cnt, ret = NO_QUOTA, chuid = (iattr->ia_valid & ATTR_UID) && inode->i_uid != iattr->ia_uid, 1397 chgid = (iattr->ia_valid & ATTR_GID) && inode->i_gid != iattr->ia_gid; 1398 char warntype_to[MAXQUOTAS]; 1399 char warntype_from_inodes[MAXQUOTAS], warntype_from_space[MAXQUOTAS]; 1400 1401 /* First test before acquiring mutex - solves deadlocks when we 1402 * re-enter the quota code and are already holding the mutex */ 1403 if (IS_NOQUOTA(inode)) 1404 return QUOTA_OK; 1405 /* Clear the arrays */ 1406 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1407 transfer_to[cnt] = transfer_from[cnt] = NODQUOT; 1408 warntype_to[cnt] = QUOTA_NL_NOWARN; 1409 } 1410 down_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1411 /* Now recheck reliably when holding dqptr_sem */ 1412 if (IS_NOQUOTA(inode)) { /* File without quota accounting? */ 1413 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1414 return QUOTA_OK; 1415 } 1416 /* First build the transfer_to list - here we can block on 1417 * reading/instantiating of dquots. We know that the transaction for 1418 * us was already started so we don't violate lock ranking here */ 1419 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1420 switch (cnt) { 1421 case USRQUOTA: 1422 if (!chuid) 1423 continue; 1424 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_uid, cnt); 1425 break; 1426 case GRPQUOTA: 1427 if (!chgid) 1428 continue; 1429 transfer_to[cnt] = dqget(inode->i_sb, iattr->ia_gid, cnt); 1430 break; 1431 } 1432 } 1433 spin_lock(&dq_data_lock); 1434 space = inode_get_bytes(inode); 1435 /* Build the transfer_from list and check the limits */ 1436 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1437 if (transfer_to[cnt] == NODQUOT) 1438 continue; 1439 transfer_from[cnt] = inode->i_dquot[cnt]; 1440 if (check_idq(transfer_to[cnt], 1, warntype_to + cnt) == 1441 NO_QUOTA || check_bdq(transfer_to[cnt], space, 0, 1442 warntype_to + cnt) == NO_QUOTA) 1443 goto warn_put_all; 1444 } 1445 1446 /* 1447 * Finally perform the needed transfer from transfer_from to transfer_to 1448 */ 1449 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1450 /* 1451 * Skip changes for same uid or gid or for turned off quota-type. 1452 */ 1453 if (transfer_to[cnt] == NODQUOT) 1454 continue; 1455 1456 /* Due to IO error we might not have transfer_from[] structure */ 1457 if (transfer_from[cnt]) { 1458 warntype_from_inodes[cnt] = 1459 info_idq_free(transfer_from[cnt], 1); 1460 warntype_from_space[cnt] = 1461 info_bdq_free(transfer_from[cnt], space); 1462 dquot_decr_inodes(transfer_from[cnt], 1); 1463 dquot_decr_space(transfer_from[cnt], space); 1464 } 1465 1466 dquot_incr_inodes(transfer_to[cnt], 1); 1467 dquot_incr_space(transfer_to[cnt], space); 1468 1469 inode->i_dquot[cnt] = transfer_to[cnt]; 1470 } 1471 ret = QUOTA_OK; 1472 warn_put_all: 1473 spin_unlock(&dq_data_lock); 1474 /* Dirtify all the dquots - this can block when journalling */ 1475 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1476 if (transfer_from[cnt]) 1477 mark_dquot_dirty(transfer_from[cnt]); 1478 if (transfer_to[cnt]) 1479 mark_dquot_dirty(transfer_to[cnt]); 1480 } 1481 flush_warnings(transfer_to, warntype_to); 1482 flush_warnings(transfer_from, warntype_from_inodes); 1483 flush_warnings(transfer_from, warntype_from_space); 1484 1485 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1486 if (ret == QUOTA_OK && transfer_from[cnt] != NODQUOT) 1487 dqput(transfer_from[cnt]); 1488 if (ret == NO_QUOTA && transfer_to[cnt] != NODQUOT) 1489 dqput(transfer_to[cnt]); 1490 } 1491 up_write(&sb_dqopt(inode->i_sb)->dqptr_sem); 1492 return ret; 1493 } 1494 1495 /* Wrapper for transferring ownership of an inode */ 1496 int vfs_dq_transfer(struct inode *inode, struct iattr *iattr) 1497 { 1498 if (sb_any_quota_enabled(inode->i_sb) && !IS_NOQUOTA(inode)) { 1499 vfs_dq_init(inode); 1500 if (inode->i_sb->dq_op->transfer(inode, iattr) == NO_QUOTA) 1501 return 1; 1502 } 1503 return 0; 1504 } 1505 1506 1507 /* 1508 * Write info of quota file to disk 1509 */ 1510 int dquot_commit_info(struct super_block *sb, int type) 1511 { 1512 int ret; 1513 struct quota_info *dqopt = sb_dqopt(sb); 1514 1515 mutex_lock(&dqopt->dqio_mutex); 1516 ret = dqopt->ops[type]->write_file_info(sb, type); 1517 mutex_unlock(&dqopt->dqio_mutex); 1518 return ret; 1519 } 1520 1521 /* 1522 * Definitions of diskquota operations. 1523 */ 1524 struct dquot_operations dquot_operations = { 1525 .initialize = dquot_initialize, 1526 .drop = dquot_drop, 1527 .alloc_space = dquot_alloc_space, 1528 .alloc_inode = dquot_alloc_inode, 1529 .free_space = dquot_free_space, 1530 .free_inode = dquot_free_inode, 1531 .transfer = dquot_transfer, 1532 .write_dquot = dquot_commit, 1533 .acquire_dquot = dquot_acquire, 1534 .release_dquot = dquot_release, 1535 .mark_dirty = dquot_mark_dquot_dirty, 1536 .write_info = dquot_commit_info 1537 }; 1538 1539 static inline void set_enable_flags(struct quota_info *dqopt, int type) 1540 { 1541 switch (type) { 1542 case USRQUOTA: 1543 dqopt->flags |= DQUOT_USR_ENABLED; 1544 dqopt->flags &= ~DQUOT_USR_SUSPENDED; 1545 break; 1546 case GRPQUOTA: 1547 dqopt->flags |= DQUOT_GRP_ENABLED; 1548 dqopt->flags &= ~DQUOT_GRP_SUSPENDED; 1549 break; 1550 } 1551 } 1552 1553 static inline void reset_enable_flags(struct quota_info *dqopt, int type, 1554 int remount) 1555 { 1556 switch (type) { 1557 case USRQUOTA: 1558 dqopt->flags &= ~DQUOT_USR_ENABLED; 1559 if (remount) 1560 dqopt->flags |= DQUOT_USR_SUSPENDED; 1561 else 1562 dqopt->flags &= ~DQUOT_USR_SUSPENDED; 1563 break; 1564 case GRPQUOTA: 1565 dqopt->flags &= ~DQUOT_GRP_ENABLED; 1566 if (remount) 1567 dqopt->flags |= DQUOT_GRP_SUSPENDED; 1568 else 1569 dqopt->flags &= ~DQUOT_GRP_SUSPENDED; 1570 break; 1571 } 1572 } 1573 1574 1575 /* 1576 * Turn quota off on a device. type == -1 ==> quotaoff for all types (umount) 1577 */ 1578 int vfs_quota_off(struct super_block *sb, int type, int remount) 1579 { 1580 int cnt, ret = 0; 1581 struct quota_info *dqopt = sb_dqopt(sb); 1582 struct inode *toputinode[MAXQUOTAS]; 1583 1584 /* We need to serialize quota_off() for device */ 1585 mutex_lock(&dqopt->dqonoff_mutex); 1586 1587 /* 1588 * Skip everything if there's nothing to do. We have to do this because 1589 * sometimes we are called when fill_super() failed and calling 1590 * sync_fs() in such cases does no good. 1591 */ 1592 if (!sb_any_quota_enabled(sb) && !sb_any_quota_suspended(sb)) { 1593 mutex_unlock(&dqopt->dqonoff_mutex); 1594 return 0; 1595 } 1596 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1597 toputinode[cnt] = NULL; 1598 if (type != -1 && cnt != type) 1599 continue; 1600 /* If we keep inodes of quota files after remount and quotaoff 1601 * is called, drop kept inodes. */ 1602 if (!remount && sb_has_quota_suspended(sb, cnt)) { 1603 iput(dqopt->files[cnt]); 1604 dqopt->files[cnt] = NULL; 1605 reset_enable_flags(dqopt, cnt, 0); 1606 continue; 1607 } 1608 if (!sb_has_quota_enabled(sb, cnt)) 1609 continue; 1610 reset_enable_flags(dqopt, cnt, remount); 1611 1612 /* Note: these are blocking operations */ 1613 drop_dquot_ref(sb, cnt); 1614 invalidate_dquots(sb, cnt); 1615 /* 1616 * Now all dquots should be invalidated, all writes done so we should be only 1617 * users of the info. No locks needed. 1618 */ 1619 if (info_dirty(&dqopt->info[cnt])) 1620 sb->dq_op->write_info(sb, cnt); 1621 if (dqopt->ops[cnt]->free_file_info) 1622 dqopt->ops[cnt]->free_file_info(sb, cnt); 1623 put_quota_format(dqopt->info[cnt].dqi_format); 1624 1625 toputinode[cnt] = dqopt->files[cnt]; 1626 if (!remount) 1627 dqopt->files[cnt] = NULL; 1628 dqopt->info[cnt].dqi_flags = 0; 1629 dqopt->info[cnt].dqi_igrace = 0; 1630 dqopt->info[cnt].dqi_bgrace = 0; 1631 dqopt->ops[cnt] = NULL; 1632 } 1633 mutex_unlock(&dqopt->dqonoff_mutex); 1634 /* Sync the superblock so that buffers with quota data are written to 1635 * disk (and so userspace sees correct data afterwards). */ 1636 if (sb->s_op->sync_fs) 1637 sb->s_op->sync_fs(sb, 1); 1638 sync_blockdev(sb->s_bdev); 1639 /* Now the quota files are just ordinary files and we can set the 1640 * inode flags back. Moreover we discard the pagecache so that 1641 * userspace sees the writes we did bypassing the pagecache. We 1642 * must also discard the blockdev buffers so that we see the 1643 * changes done by userspace on the next quotaon() */ 1644 for (cnt = 0; cnt < MAXQUOTAS; cnt++) 1645 if (toputinode[cnt]) { 1646 mutex_lock(&dqopt->dqonoff_mutex); 1647 /* If quota was reenabled in the meantime, we have 1648 * nothing to do */ 1649 if (!sb_has_quota_enabled(sb, cnt)) { 1650 mutex_lock_nested(&toputinode[cnt]->i_mutex, I_MUTEX_QUOTA); 1651 toputinode[cnt]->i_flags &= ~(S_IMMUTABLE | 1652 S_NOATIME | S_NOQUOTA); 1653 truncate_inode_pages(&toputinode[cnt]->i_data, 0); 1654 mutex_unlock(&toputinode[cnt]->i_mutex); 1655 mark_inode_dirty(toputinode[cnt]); 1656 } 1657 mutex_unlock(&dqopt->dqonoff_mutex); 1658 /* On remount RO, we keep the inode pointer so that we 1659 * can reenable quota on the subsequent remount RW. 1660 * But we have better not keep inode pointer when there 1661 * is pending delete on the quota file... */ 1662 if (!remount) 1663 iput(toputinode[cnt]); 1664 else if (!toputinode[cnt]->i_nlink) 1665 ret = -EBUSY; 1666 } 1667 if (sb->s_bdev) 1668 invalidate_bdev(sb->s_bdev); 1669 return ret; 1670 } 1671 1672 /* 1673 * Turn quotas on on a device 1674 */ 1675 1676 /* Helper function when we already have the inode */ 1677 static int vfs_quota_on_inode(struct inode *inode, int type, int format_id) 1678 { 1679 struct quota_format_type *fmt = find_quota_format(format_id); 1680 struct super_block *sb = inode->i_sb; 1681 struct quota_info *dqopt = sb_dqopt(sb); 1682 int error; 1683 int oldflags = -1; 1684 1685 if (!fmt) 1686 return -ESRCH; 1687 if (!S_ISREG(inode->i_mode)) { 1688 error = -EACCES; 1689 goto out_fmt; 1690 } 1691 if (IS_RDONLY(inode)) { 1692 error = -EROFS; 1693 goto out_fmt; 1694 } 1695 if (!sb->s_op->quota_write || !sb->s_op->quota_read) { 1696 error = -EINVAL; 1697 goto out_fmt; 1698 } 1699 1700 /* As we bypass the pagecache we must now flush the inode so that 1701 * we see all the changes from userspace... */ 1702 write_inode_now(inode, 1); 1703 /* And now flush the block cache so that kernel sees the changes */ 1704 invalidate_bdev(sb->s_bdev); 1705 mutex_lock(&inode->i_mutex); 1706 mutex_lock(&dqopt->dqonoff_mutex); 1707 if (sb_has_quota_enabled(sb, type) || 1708 sb_has_quota_suspended(sb, type)) { 1709 error = -EBUSY; 1710 goto out_lock; 1711 } 1712 /* We don't want quota and atime on quota files (deadlocks possible) 1713 * Also nobody should write to the file - we use special IO operations 1714 * which ignore the immutable bit. */ 1715 down_write(&dqopt->dqptr_sem); 1716 oldflags = inode->i_flags & (S_NOATIME | S_IMMUTABLE | S_NOQUOTA); 1717 inode->i_flags |= S_NOQUOTA | S_NOATIME | S_IMMUTABLE; 1718 up_write(&dqopt->dqptr_sem); 1719 sb->dq_op->drop(inode); 1720 1721 error = -EIO; 1722 dqopt->files[type] = igrab(inode); 1723 if (!dqopt->files[type]) 1724 goto out_lock; 1725 error = -EINVAL; 1726 if (!fmt->qf_ops->check_quota_file(sb, type)) 1727 goto out_file_init; 1728 1729 dqopt->ops[type] = fmt->qf_ops; 1730 dqopt->info[type].dqi_format = fmt; 1731 dqopt->info[type].dqi_fmt_id = format_id; 1732 INIT_LIST_HEAD(&dqopt->info[type].dqi_dirty_list); 1733 mutex_lock(&dqopt->dqio_mutex); 1734 if ((error = dqopt->ops[type]->read_file_info(sb, type)) < 0) { 1735 mutex_unlock(&dqopt->dqio_mutex); 1736 goto out_file_init; 1737 } 1738 mutex_unlock(&dqopt->dqio_mutex); 1739 mutex_unlock(&inode->i_mutex); 1740 set_enable_flags(dqopt, type); 1741 1742 add_dquot_ref(sb, type); 1743 mutex_unlock(&dqopt->dqonoff_mutex); 1744 1745 return 0; 1746 1747 out_file_init: 1748 dqopt->files[type] = NULL; 1749 iput(inode); 1750 out_lock: 1751 mutex_unlock(&dqopt->dqonoff_mutex); 1752 if (oldflags != -1) { 1753 down_write(&dqopt->dqptr_sem); 1754 /* Set the flags back (in the case of accidental quotaon() 1755 * on a wrong file we don't want to mess up the flags) */ 1756 inode->i_flags &= ~(S_NOATIME | S_NOQUOTA | S_IMMUTABLE); 1757 inode->i_flags |= oldflags; 1758 up_write(&dqopt->dqptr_sem); 1759 } 1760 mutex_unlock(&inode->i_mutex); 1761 out_fmt: 1762 put_quota_format(fmt); 1763 1764 return error; 1765 } 1766 1767 /* Reenable quotas on remount RW */ 1768 static int vfs_quota_on_remount(struct super_block *sb, int type) 1769 { 1770 struct quota_info *dqopt = sb_dqopt(sb); 1771 struct inode *inode; 1772 int ret; 1773 1774 mutex_lock(&dqopt->dqonoff_mutex); 1775 if (!sb_has_quota_suspended(sb, type)) { 1776 mutex_unlock(&dqopt->dqonoff_mutex); 1777 return 0; 1778 } 1779 BUG_ON(sb_has_quota_enabled(sb, type)); 1780 1781 inode = dqopt->files[type]; 1782 dqopt->files[type] = NULL; 1783 reset_enable_flags(dqopt, type, 0); 1784 mutex_unlock(&dqopt->dqonoff_mutex); 1785 1786 ret = vfs_quota_on_inode(inode, type, dqopt->info[type].dqi_fmt_id); 1787 iput(inode); 1788 1789 return ret; 1790 } 1791 1792 int vfs_quota_on_path(struct super_block *sb, int type, int format_id, 1793 struct path *path) 1794 { 1795 int error = security_quota_on(path->dentry); 1796 if (error) 1797 return error; 1798 /* Quota file not on the same filesystem? */ 1799 if (path->mnt->mnt_sb != sb) 1800 error = -EXDEV; 1801 else 1802 error = vfs_quota_on_inode(path->dentry->d_inode, type, 1803 format_id); 1804 return error; 1805 } 1806 1807 /* Actual function called from quotactl() */ 1808 int vfs_quota_on(struct super_block *sb, int type, int format_id, char *name, 1809 int remount) 1810 { 1811 struct path path; 1812 int error; 1813 1814 if (remount) 1815 return vfs_quota_on_remount(sb, type); 1816 1817 error = kern_path(name, LOOKUP_FOLLOW, &path); 1818 if (!error) { 1819 error = vfs_quota_on_path(sb, type, format_id, &path); 1820 path_put(&path); 1821 } 1822 return error; 1823 } 1824 1825 /* 1826 * This function is used when filesystem needs to initialize quotas 1827 * during mount time. 1828 */ 1829 int vfs_quota_on_mount(struct super_block *sb, char *qf_name, 1830 int format_id, int type) 1831 { 1832 struct dentry *dentry; 1833 int error; 1834 1835 dentry = lookup_one_len(qf_name, sb->s_root, strlen(qf_name)); 1836 if (IS_ERR(dentry)) 1837 return PTR_ERR(dentry); 1838 1839 if (!dentry->d_inode) { 1840 error = -ENOENT; 1841 goto out; 1842 } 1843 1844 error = security_quota_on(dentry); 1845 if (!error) 1846 error = vfs_quota_on_inode(dentry->d_inode, type, format_id); 1847 1848 out: 1849 dput(dentry); 1850 return error; 1851 } 1852 1853 /* Wrapper to turn on quotas when remounting rw */ 1854 int vfs_dq_quota_on_remount(struct super_block *sb) 1855 { 1856 int cnt; 1857 int ret = 0, err; 1858 1859 if (!sb->s_qcop || !sb->s_qcop->quota_on) 1860 return -ENOSYS; 1861 for (cnt = 0; cnt < MAXQUOTAS; cnt++) { 1862 err = sb->s_qcop->quota_on(sb, cnt, 0, NULL, 1); 1863 if (err < 0 && !ret) 1864 ret = err; 1865 } 1866 return ret; 1867 } 1868 1869 /* Generic routine for getting common part of quota structure */ 1870 static void do_get_dqblk(struct dquot *dquot, struct if_dqblk *di) 1871 { 1872 struct mem_dqblk *dm = &dquot->dq_dqb; 1873 1874 spin_lock(&dq_data_lock); 1875 di->dqb_bhardlimit = dm->dqb_bhardlimit; 1876 di->dqb_bsoftlimit = dm->dqb_bsoftlimit; 1877 di->dqb_curspace = dm->dqb_curspace; 1878 di->dqb_ihardlimit = dm->dqb_ihardlimit; 1879 di->dqb_isoftlimit = dm->dqb_isoftlimit; 1880 di->dqb_curinodes = dm->dqb_curinodes; 1881 di->dqb_btime = dm->dqb_btime; 1882 di->dqb_itime = dm->dqb_itime; 1883 di->dqb_valid = QIF_ALL; 1884 spin_unlock(&dq_data_lock); 1885 } 1886 1887 int vfs_get_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) 1888 { 1889 struct dquot *dquot; 1890 1891 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 1892 if (!(dquot = dqget(sb, id, type))) { 1893 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 1894 return -ESRCH; 1895 } 1896 do_get_dqblk(dquot, di); 1897 dqput(dquot); 1898 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 1899 return 0; 1900 } 1901 1902 /* Generic routine for setting common part of quota structure */ 1903 static int do_set_dqblk(struct dquot *dquot, struct if_dqblk *di) 1904 { 1905 struct mem_dqblk *dm = &dquot->dq_dqb; 1906 int check_blim = 0, check_ilim = 0; 1907 struct mem_dqinfo *dqi = &sb_dqopt(dquot->dq_sb)->info[dquot->dq_type]; 1908 1909 if ((di->dqb_valid & QIF_BLIMITS && 1910 (di->dqb_bhardlimit > dqi->dqi_maxblimit || 1911 di->dqb_bsoftlimit > dqi->dqi_maxblimit)) || 1912 (di->dqb_valid & QIF_ILIMITS && 1913 (di->dqb_ihardlimit > dqi->dqi_maxilimit || 1914 di->dqb_isoftlimit > dqi->dqi_maxilimit))) 1915 return -ERANGE; 1916 1917 spin_lock(&dq_data_lock); 1918 if (di->dqb_valid & QIF_SPACE) { 1919 dm->dqb_curspace = di->dqb_curspace; 1920 check_blim = 1; 1921 } 1922 if (di->dqb_valid & QIF_BLIMITS) { 1923 dm->dqb_bsoftlimit = di->dqb_bsoftlimit; 1924 dm->dqb_bhardlimit = di->dqb_bhardlimit; 1925 check_blim = 1; 1926 } 1927 if (di->dqb_valid & QIF_INODES) { 1928 dm->dqb_curinodes = di->dqb_curinodes; 1929 check_ilim = 1; 1930 } 1931 if (di->dqb_valid & QIF_ILIMITS) { 1932 dm->dqb_isoftlimit = di->dqb_isoftlimit; 1933 dm->dqb_ihardlimit = di->dqb_ihardlimit; 1934 check_ilim = 1; 1935 } 1936 if (di->dqb_valid & QIF_BTIME) 1937 dm->dqb_btime = di->dqb_btime; 1938 if (di->dqb_valid & QIF_ITIME) 1939 dm->dqb_itime = di->dqb_itime; 1940 1941 if (check_blim) { 1942 if (!dm->dqb_bsoftlimit || toqb(dm->dqb_curspace) < dm->dqb_bsoftlimit) { 1943 dm->dqb_btime = 0; 1944 clear_bit(DQ_BLKS_B, &dquot->dq_flags); 1945 } 1946 else if (!(di->dqb_valid & QIF_BTIME)) /* Set grace only if user hasn't provided his own... */ 1947 dm->dqb_btime = get_seconds() + dqi->dqi_bgrace; 1948 } 1949 if (check_ilim) { 1950 if (!dm->dqb_isoftlimit || dm->dqb_curinodes < dm->dqb_isoftlimit) { 1951 dm->dqb_itime = 0; 1952 clear_bit(DQ_INODES_B, &dquot->dq_flags); 1953 } 1954 else if (!(di->dqb_valid & QIF_ITIME)) /* Set grace only if user hasn't provided his own... */ 1955 dm->dqb_itime = get_seconds() + dqi->dqi_igrace; 1956 } 1957 if (dm->dqb_bhardlimit || dm->dqb_bsoftlimit || dm->dqb_ihardlimit || dm->dqb_isoftlimit) 1958 clear_bit(DQ_FAKE_B, &dquot->dq_flags); 1959 else 1960 set_bit(DQ_FAKE_B, &dquot->dq_flags); 1961 spin_unlock(&dq_data_lock); 1962 mark_dquot_dirty(dquot); 1963 1964 return 0; 1965 } 1966 1967 int vfs_set_dqblk(struct super_block *sb, int type, qid_t id, struct if_dqblk *di) 1968 { 1969 struct dquot *dquot; 1970 int rc; 1971 1972 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 1973 if (!(dquot = dqget(sb, id, type))) { 1974 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 1975 return -ESRCH; 1976 } 1977 rc = do_set_dqblk(dquot, di); 1978 dqput(dquot); 1979 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 1980 return rc; 1981 } 1982 1983 /* Generic routine for getting common part of quota file information */ 1984 int vfs_get_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 1985 { 1986 struct mem_dqinfo *mi; 1987 1988 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 1989 if (!sb_has_quota_enabled(sb, type)) { 1990 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 1991 return -ESRCH; 1992 } 1993 mi = sb_dqopt(sb)->info + type; 1994 spin_lock(&dq_data_lock); 1995 ii->dqi_bgrace = mi->dqi_bgrace; 1996 ii->dqi_igrace = mi->dqi_igrace; 1997 ii->dqi_flags = mi->dqi_flags & DQF_MASK; 1998 ii->dqi_valid = IIF_ALL; 1999 spin_unlock(&dq_data_lock); 2000 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2001 return 0; 2002 } 2003 2004 /* Generic routine for setting common part of quota file information */ 2005 int vfs_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) 2006 { 2007 struct mem_dqinfo *mi; 2008 2009 mutex_lock(&sb_dqopt(sb)->dqonoff_mutex); 2010 if (!sb_has_quota_enabled(sb, type)) { 2011 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2012 return -ESRCH; 2013 } 2014 mi = sb_dqopt(sb)->info + type; 2015 spin_lock(&dq_data_lock); 2016 if (ii->dqi_valid & IIF_BGRACE) 2017 mi->dqi_bgrace = ii->dqi_bgrace; 2018 if (ii->dqi_valid & IIF_IGRACE) 2019 mi->dqi_igrace = ii->dqi_igrace; 2020 if (ii->dqi_valid & IIF_FLAGS) 2021 mi->dqi_flags = (mi->dqi_flags & ~DQF_MASK) | (ii->dqi_flags & DQF_MASK); 2022 spin_unlock(&dq_data_lock); 2023 mark_info_dirty(sb, type); 2024 /* Force write to disk */ 2025 sb->dq_op->write_info(sb, type); 2026 mutex_unlock(&sb_dqopt(sb)->dqonoff_mutex); 2027 return 0; 2028 } 2029 2030 struct quotactl_ops vfs_quotactl_ops = { 2031 .quota_on = vfs_quota_on, 2032 .quota_off = vfs_quota_off, 2033 .quota_sync = vfs_quota_sync, 2034 .get_info = vfs_get_dqinfo, 2035 .set_info = vfs_set_dqinfo, 2036 .get_dqblk = vfs_get_dqblk, 2037 .set_dqblk = vfs_set_dqblk 2038 }; 2039 2040 static ctl_table fs_dqstats_table[] = { 2041 { 2042 .ctl_name = FS_DQ_LOOKUPS, 2043 .procname = "lookups", 2044 .data = &dqstats.lookups, 2045 .maxlen = sizeof(int), 2046 .mode = 0444, 2047 .proc_handler = &proc_dointvec, 2048 }, 2049 { 2050 .ctl_name = FS_DQ_DROPS, 2051 .procname = "drops", 2052 .data = &dqstats.drops, 2053 .maxlen = sizeof(int), 2054 .mode = 0444, 2055 .proc_handler = &proc_dointvec, 2056 }, 2057 { 2058 .ctl_name = FS_DQ_READS, 2059 .procname = "reads", 2060 .data = &dqstats.reads, 2061 .maxlen = sizeof(int), 2062 .mode = 0444, 2063 .proc_handler = &proc_dointvec, 2064 }, 2065 { 2066 .ctl_name = FS_DQ_WRITES, 2067 .procname = "writes", 2068 .data = &dqstats.writes, 2069 .maxlen = sizeof(int), 2070 .mode = 0444, 2071 .proc_handler = &proc_dointvec, 2072 }, 2073 { 2074 .ctl_name = FS_DQ_CACHE_HITS, 2075 .procname = "cache_hits", 2076 .data = &dqstats.cache_hits, 2077 .maxlen = sizeof(int), 2078 .mode = 0444, 2079 .proc_handler = &proc_dointvec, 2080 }, 2081 { 2082 .ctl_name = FS_DQ_ALLOCATED, 2083 .procname = "allocated_dquots", 2084 .data = &dqstats.allocated_dquots, 2085 .maxlen = sizeof(int), 2086 .mode = 0444, 2087 .proc_handler = &proc_dointvec, 2088 }, 2089 { 2090 .ctl_name = FS_DQ_FREE, 2091 .procname = "free_dquots", 2092 .data = &dqstats.free_dquots, 2093 .maxlen = sizeof(int), 2094 .mode = 0444, 2095 .proc_handler = &proc_dointvec, 2096 }, 2097 { 2098 .ctl_name = FS_DQ_SYNCS, 2099 .procname = "syncs", 2100 .data = &dqstats.syncs, 2101 .maxlen = sizeof(int), 2102 .mode = 0444, 2103 .proc_handler = &proc_dointvec, 2104 }, 2105 #ifdef CONFIG_PRINT_QUOTA_WARNING 2106 { 2107 .ctl_name = FS_DQ_WARNINGS, 2108 .procname = "warnings", 2109 .data = &flag_print_warnings, 2110 .maxlen = sizeof(int), 2111 .mode = 0644, 2112 .proc_handler = &proc_dointvec, 2113 }, 2114 #endif 2115 { .ctl_name = 0 }, 2116 }; 2117 2118 static ctl_table fs_table[] = { 2119 { 2120 .ctl_name = FS_DQSTATS, 2121 .procname = "quota", 2122 .mode = 0555, 2123 .child = fs_dqstats_table, 2124 }, 2125 { .ctl_name = 0 }, 2126 }; 2127 2128 static ctl_table sys_table[] = { 2129 { 2130 .ctl_name = CTL_FS, 2131 .procname = "fs", 2132 .mode = 0555, 2133 .child = fs_table, 2134 }, 2135 { .ctl_name = 0 }, 2136 }; 2137 2138 static int __init dquot_init(void) 2139 { 2140 int i; 2141 unsigned long nr_hash, order; 2142 2143 printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__); 2144 2145 register_sysctl_table(sys_table); 2146 2147 dquot_cachep = kmem_cache_create("dquot", 2148 sizeof(struct dquot), sizeof(unsigned long) * 4, 2149 (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| 2150 SLAB_MEM_SPREAD|SLAB_PANIC), 2151 NULL); 2152 2153 order = 0; 2154 dquot_hash = (struct hlist_head *)__get_free_pages(GFP_ATOMIC, order); 2155 if (!dquot_hash) 2156 panic("Cannot create dquot hash table"); 2157 2158 /* Find power-of-two hlist_heads which can fit into allocation */ 2159 nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head); 2160 dq_hash_bits = 0; 2161 do { 2162 dq_hash_bits++; 2163 } while (nr_hash >> dq_hash_bits); 2164 dq_hash_bits--; 2165 2166 nr_hash = 1UL << dq_hash_bits; 2167 dq_hash_mask = nr_hash - 1; 2168 for (i = 0; i < nr_hash; i++) 2169 INIT_HLIST_HEAD(dquot_hash + i); 2170 2171 printk("Dquot-cache hash table entries: %ld (order %ld, %ld bytes)\n", 2172 nr_hash, order, (PAGE_SIZE << order)); 2173 2174 register_shrinker(&dqcache_shrinker); 2175 2176 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE 2177 if (genl_register_family("a_genl_family) != 0) 2178 printk(KERN_ERR "VFS: Failed to create quota netlink interface.\n"); 2179 #endif 2180 2181 return 0; 2182 } 2183 module_init(dquot_init); 2184 2185 EXPORT_SYMBOL(register_quota_format); 2186 EXPORT_SYMBOL(unregister_quota_format); 2187 EXPORT_SYMBOL(dqstats); 2188 EXPORT_SYMBOL(dq_data_lock); 2189 EXPORT_SYMBOL(vfs_quota_on); 2190 EXPORT_SYMBOL(vfs_quota_on_path); 2191 EXPORT_SYMBOL(vfs_quota_on_mount); 2192 EXPORT_SYMBOL(vfs_quota_off); 2193 EXPORT_SYMBOL(vfs_quota_sync); 2194 EXPORT_SYMBOL(vfs_get_dqinfo); 2195 EXPORT_SYMBOL(vfs_set_dqinfo); 2196 EXPORT_SYMBOL(vfs_get_dqblk); 2197 EXPORT_SYMBOL(vfs_set_dqblk); 2198 EXPORT_SYMBOL(dquot_commit); 2199 EXPORT_SYMBOL(dquot_commit_info); 2200 EXPORT_SYMBOL(dquot_acquire); 2201 EXPORT_SYMBOL(dquot_release); 2202 EXPORT_SYMBOL(dquot_mark_dquot_dirty); 2203 EXPORT_SYMBOL(dquot_initialize); 2204 EXPORT_SYMBOL(dquot_drop); 2205 EXPORT_SYMBOL(vfs_dq_drop); 2206 EXPORT_SYMBOL(dquot_alloc_space); 2207 EXPORT_SYMBOL(dquot_alloc_inode); 2208 EXPORT_SYMBOL(dquot_free_space); 2209 EXPORT_SYMBOL(dquot_free_inode); 2210 EXPORT_SYMBOL(dquot_transfer); 2211 EXPORT_SYMBOL(vfs_dq_transfer); 2212 EXPORT_SYMBOL(vfs_dq_quota_on_remount);
Cache object: 5c0d92cf66819d45fe55fbf29e41f3f8
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