quota_tree.c 16.5 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
/*
 *	vfsv0 quota IO operations on file
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/dqblk_v2.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/quotaops.h>

#include <asm/byteorder.h>

#include "quota_tree.h"

MODULE_AUTHOR("Jan Kara");
MODULE_DESCRIPTION("Quota trie support");
MODULE_LICENSE("GPL");

#define __QUOTA_QT_PARANOIA

static int get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
{
	unsigned int epb = info->dqi_usable_bs >> 2;

	depth = info->dqi_qtree_depth - depth - 1;
	while (depth--)
		id /= epb;
	return id % epb;
}

/* Number of entries in one blocks */
J
Jan Kara 已提交
36
static int qtree_dqstr_in_blk(struct qtree_mem_dqinfo *info)
37 38 39 40 41
{
	return (info->dqi_usable_bs - sizeof(struct qt_disk_dqdbheader))
	       / info->dqi_entry_size;
}

42
static char *getdqbuf(size_t size)
43
{
44
	char *buf = kmalloc(size, GFP_NOFS);
45
	if (!buf)
J
Jan Kara 已提交
46 47
		printk(KERN_WARNING
		       "VFS: Not enough memory for quota buffers.\n");
48 49 50
	return buf;
}

J
Jan Kara 已提交
51
static ssize_t read_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
52 53 54 55
{
	struct super_block *sb = info->dqi_sb;

	memset(buf, 0, info->dqi_usable_bs);
56
	return sb->s_op->quota_read(sb, info->dqi_type, buf,
57 58 59
	       info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
}

J
Jan Kara 已提交
60
static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
61 62 63
{
	struct super_block *sb = info->dqi_sb;

64
	return sb->s_op->quota_write(sb, info->dqi_type, buf,
65 66 67 68 69 70
	       info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
}

/* Remove empty block from list and return it */
static int get_free_dqblk(struct qtree_mem_dqinfo *info)
{
71
	char *buf = getdqbuf(info->dqi_usable_bs);
72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94
	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
	int ret, blk;

	if (!buf)
		return -ENOMEM;
	if (info->dqi_free_blk) {
		blk = info->dqi_free_blk;
		ret = read_blk(info, blk, buf);
		if (ret < 0)
			goto out_buf;
		info->dqi_free_blk = le32_to_cpu(dh->dqdh_next_free);
	}
	else {
		memset(buf, 0, info->dqi_usable_bs);
		/* Assure block allocation... */
		ret = write_blk(info, info->dqi_blocks, buf);
		if (ret < 0)
			goto out_buf;
		blk = info->dqi_blocks++;
	}
	mark_info_dirty(info->dqi_sb, info->dqi_type);
	ret = blk;
out_buf:
95
	kfree(buf);
96 97 98 99
	return ret;
}

/* Insert empty block to the list */
100
static int put_free_dqblk(struct qtree_mem_dqinfo *info, char *buf, uint blk)
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
{
	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
	int err;

	dh->dqdh_next_free = cpu_to_le32(info->dqi_free_blk);
	dh->dqdh_prev_free = cpu_to_le32(0);
	dh->dqdh_entries = cpu_to_le16(0);
	err = write_blk(info, blk, buf);
	if (err < 0)
		return err;
	info->dqi_free_blk = blk;
	mark_info_dirty(info->dqi_sb, info->dqi_type);
	return 0;
}

/* Remove given block from the list of blocks with free entries */
J
Jan Kara 已提交
117 118
static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
			       uint blk)
119
{
120
	char *tmpbuf = getdqbuf(info->dqi_usable_bs);
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150
	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
	uint nextblk = le32_to_cpu(dh->dqdh_next_free);
	uint prevblk = le32_to_cpu(dh->dqdh_prev_free);
	int err;

	if (!tmpbuf)
		return -ENOMEM;
	if (nextblk) {
		err = read_blk(info, nextblk, tmpbuf);
		if (err < 0)
			goto out_buf;
		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
							dh->dqdh_prev_free;
		err = write_blk(info, nextblk, tmpbuf);
		if (err < 0)
			goto out_buf;
	}
	if (prevblk) {
		err = read_blk(info, prevblk, tmpbuf);
		if (err < 0)
			goto out_buf;
		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_next_free =
							dh->dqdh_next_free;
		err = write_blk(info, prevblk, tmpbuf);
		if (err < 0)
			goto out_buf;
	} else {
		info->dqi_free_entry = nextblk;
		mark_info_dirty(info->dqi_sb, info->dqi_type);
	}
151
	kfree(tmpbuf);
152 153 154
	dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
	/* No matter whether write succeeds block is out of list */
	if (write_blk(info, blk, buf) < 0)
J
Jan Kara 已提交
155 156 157
		printk(KERN_ERR
		       "VFS: Can't write block (%u) with free entries.\n",
		       blk);
158 159
	return 0;
out_buf:
160
	kfree(tmpbuf);
161 162 163 164
	return err;
}

/* Insert given block to the beginning of list with free entries */
J
Jan Kara 已提交
165 166
static int insert_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
			       uint blk)
167
{
168
	char *tmpbuf = getdqbuf(info->dqi_usable_bs);
169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188
	struct qt_disk_dqdbheader *dh = (struct qt_disk_dqdbheader *)buf;
	int err;

	if (!tmpbuf)
		return -ENOMEM;
	dh->dqdh_next_free = cpu_to_le32(info->dqi_free_entry);
	dh->dqdh_prev_free = cpu_to_le32(0);
	err = write_blk(info, blk, buf);
	if (err < 0)
		goto out_buf;
	if (info->dqi_free_entry) {
		err = read_blk(info, info->dqi_free_entry, tmpbuf);
		if (err < 0)
			goto out_buf;
		((struct qt_disk_dqdbheader *)tmpbuf)->dqdh_prev_free =
							cpu_to_le32(blk);
		err = write_blk(info, info->dqi_free_entry, tmpbuf);
		if (err < 0)
			goto out_buf;
	}
189
	kfree(tmpbuf);
190 191 192 193
	info->dqi_free_entry = blk;
	mark_info_dirty(info->dqi_sb, info->dqi_type);
	return 0;
out_buf:
194
	kfree(tmpbuf);
195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215
	return err;
}

/* Is the entry in the block free? */
int qtree_entry_unused(struct qtree_mem_dqinfo *info, char *disk)
{
	int i;

	for (i = 0; i < info->dqi_entry_size; i++)
		if (disk[i])
			return 0;
	return 1;
}
EXPORT_SYMBOL(qtree_entry_unused);

/* Find space for dquot */
static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
			      struct dquot *dquot, int *err)
{
	uint blk, i;
	struct qt_disk_dqdbheader *dh;
216
	char *buf = getdqbuf(info->dqi_usable_bs);
217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233
	char *ddquot;

	*err = 0;
	if (!buf) {
		*err = -ENOMEM;
		return 0;
	}
	dh = (struct qt_disk_dqdbheader *)buf;
	if (info->dqi_free_entry) {
		blk = info->dqi_free_entry;
		*err = read_blk(info, blk, buf);
		if (*err < 0)
			goto out_buf;
	} else {
		blk = get_free_dqblk(info);
		if ((int)blk < 0) {
			*err = blk;
234
			kfree(buf);
235 236 237
			return 0;
		}
		memset(buf, 0, info->dqi_usable_bs);
J
Jan Kara 已提交
238 239
		/* This is enough as the block is already zeroed and the entry
		 * list is empty... */
240 241 242 243 244 245 246 247 248 249 250 251 252 253 254
		info->dqi_free_entry = blk;
		mark_info_dirty(dquot->dq_sb, dquot->dq_type);
	}
	/* Block will be full? */
	if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
		*err = remove_free_dqentry(info, buf, blk);
		if (*err < 0) {
			printk(KERN_ERR "VFS: find_free_dqentry(): Can't "
			       "remove block (%u) from entry free list.\n",
			       blk);
			goto out_buf;
		}
	}
	le16_add_cpu(&dh->dqdh_entries, 1);
	/* Find free structure in block */
J
Jan Kara 已提交
255 256 257 258 259 260
	ddquot = buf + sizeof(struct qt_disk_dqdbheader);
	for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
		if (qtree_entry_unused(info, ddquot))
			break;
		ddquot += info->dqi_entry_size;
	}
261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
#ifdef __QUOTA_QT_PARANOIA
	if (i == qtree_dqstr_in_blk(info)) {
		printk(KERN_ERR "VFS: find_free_dqentry(): Data block full "
				"but it shouldn't.\n");
		*err = -EIO;
		goto out_buf;
	}
#endif
	*err = write_blk(info, blk, buf);
	if (*err < 0) {
		printk(KERN_ERR "VFS: find_free_dqentry(): Can't write quota "
				"data block %u.\n", blk);
		goto out_buf;
	}
	dquot->dq_off = (blk << info->dqi_blocksize_bits) +
			sizeof(struct qt_disk_dqdbheader) +
			i * info->dqi_entry_size;
278
	kfree(buf);
279 280
	return blk;
out_buf:
281
	kfree(buf);
282 283 284 285 286 287 288
	return 0;
}

/* Insert reference to structure into the trie */
static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
			  uint *treeblk, int depth)
{
289
	char *buf = getdqbuf(info->dqi_usable_bs);
290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337
	int ret = 0, newson = 0, newact = 0;
	__le32 *ref;
	uint newblk;

	if (!buf)
		return -ENOMEM;
	if (!*treeblk) {
		ret = get_free_dqblk(info);
		if (ret < 0)
			goto out_buf;
		*treeblk = ret;
		memset(buf, 0, info->dqi_usable_bs);
		newact = 1;
	} else {
		ret = read_blk(info, *treeblk, buf);
		if (ret < 0) {
			printk(KERN_ERR "VFS: Can't read tree quota block "
					"%u.\n", *treeblk);
			goto out_buf;
		}
	}
	ref = (__le32 *)buf;
	newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
	if (!newblk)
		newson = 1;
	if (depth == info->dqi_qtree_depth - 1) {
#ifdef __QUOTA_QT_PARANOIA
		if (newblk) {
			printk(KERN_ERR "VFS: Inserting already present quota "
					"entry (block %u).\n",
			       le32_to_cpu(ref[get_index(info,
						dquot->dq_id, depth)]));
			ret = -EIO;
			goto out_buf;
		}
#endif
		newblk = find_free_dqentry(info, dquot, &ret);
	} else {
		ret = do_insert_tree(info, dquot, &newblk, depth+1);
	}
	if (newson && ret >= 0) {
		ref[get_index(info, dquot->dq_id, depth)] =
							cpu_to_le32(newblk);
		ret = write_blk(info, *treeblk, buf);
	} else if (newact && ret < 0) {
		put_free_dqblk(info, buf, *treeblk);
	}
out_buf:
338
	kfree(buf);
339 340 341 342 343 344 345 346 347 348 349 350
	return ret;
}

/* Wrapper for inserting quota structure into tree */
static inline int dq_insert_tree(struct qtree_mem_dqinfo *info,
				 struct dquot *dquot)
{
	int tmp = QT_TREEOFF;
	return do_insert_tree(info, dquot, &tmp, 0);
}

/*
J
Jan Kara 已提交
351 352
 * We don't have to be afraid of deadlocks as we never have quotas on quota
 * files...
353 354 355 356 357 358
 */
int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
{
	int type = dquot->dq_type;
	struct super_block *sb = dquot->dq_sb;
	ssize_t ret;
359
	char *ddquot = getdqbuf(info->dqi_entry_size);
360 361 362 363 364 365 366 367 368 369

	if (!ddquot)
		return -ENOMEM;

	/* dq_off is guarded by dqio_mutex */
	if (!dquot->dq_off) {
		ret = dq_insert_tree(info, dquot);
		if (ret < 0) {
			printk(KERN_ERR "VFS: Error %zd occurred while "
					"creating quota.\n", ret);
370
			kfree(ddquot);
371 372 373 374 375 376
			return ret;
		}
	}
	spin_lock(&dq_data_lock);
	info->dqi_ops->mem2disk_dqblk(ddquot, dquot);
	spin_unlock(&dq_data_lock);
377 378
	ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
				    dquot->dq_off);
379 380 381 382 383 384 385 386 387
	if (ret != info->dqi_entry_size) {
		printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
		       sb->s_id);
		if (ret >= 0)
			ret = -ENOSPC;
	} else {
		ret = 0;
	}
	dqstats.writes++;
388
	kfree(ddquot);
389 390 391 392 393 394 395 396 397 398

	return ret;
}
EXPORT_SYMBOL(qtree_write_dquot);

/* Free dquot entry in data block */
static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
			uint blk)
{
	struct qt_disk_dqdbheader *dh;
399
	char *buf = getdqbuf(info->dqi_usable_bs);
400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449
	int ret = 0;

	if (!buf)
		return -ENOMEM;
	if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
		printk(KERN_ERR "VFS: Quota structure has offset to other "
		  "block (%u) than it should (%u).\n", blk,
		  (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
		goto out_buf;
	}
	ret = read_blk(info, blk, buf);
	if (ret < 0) {
		printk(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
		goto out_buf;
	}
	dh = (struct qt_disk_dqdbheader *)buf;
	le16_add_cpu(&dh->dqdh_entries, -1);
	if (!le16_to_cpu(dh->dqdh_entries)) {	/* Block got free? */
		ret = remove_free_dqentry(info, buf, blk);
		if (ret >= 0)
			ret = put_free_dqblk(info, buf, blk);
		if (ret < 0) {
			printk(KERN_ERR "VFS: Can't move quota data block (%u) "
			  "to free list.\n", blk);
			goto out_buf;
		}
	} else {
		memset(buf +
		       (dquot->dq_off & ((1 << info->dqi_blocksize_bits) - 1)),
		       0, info->dqi_entry_size);
		if (le16_to_cpu(dh->dqdh_entries) ==
		    qtree_dqstr_in_blk(info) - 1) {
			/* Insert will write block itself */
			ret = insert_free_dqentry(info, buf, blk);
			if (ret < 0) {
				printk(KERN_ERR "VFS: Can't insert quota data "
				       "block (%u) to free entry list.\n", blk);
				goto out_buf;
			}
		} else {
			ret = write_blk(info, blk, buf);
			if (ret < 0) {
				printk(KERN_ERR "VFS: Can't write quota data "
				  "block %u\n", blk);
				goto out_buf;
			}
		}
	}
	dquot->dq_off = 0;	/* Quota is now unattached */
out_buf:
450
	kfree(buf);
451 452 453 454 455 456 457
	return ret;
}

/* Remove reference to dquot from tree */
static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
		       uint *blk, int depth)
{
458
	char *buf = getdqbuf(info->dqi_usable_bs);
459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480
	int ret = 0;
	uint newblk;
	__le32 *ref = (__le32 *)buf;

	if (!buf)
		return -ENOMEM;
	ret = read_blk(info, *blk, buf);
	if (ret < 0) {
		printk(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
		goto out_buf;
	}
	newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
	if (depth == info->dqi_qtree_depth - 1) {
		ret = free_dqentry(info, dquot, newblk);
		newblk = 0;
	} else {
		ret = remove_tree(info, dquot, &newblk, depth+1);
	}
	if (ret >= 0 && !newblk) {
		int i;
		ref[get_index(info, dquot->dq_id, depth)] = cpu_to_le32(0);
		/* Block got empty? */
481 482
		for (i = 0; i < (info->dqi_usable_bs >> 2) && !ref[i]; i++)
			;
483 484 485 486 487 488 489 490 491 492 493 494 495
		/* Don't put the root block into the free block list */
		if (i == (info->dqi_usable_bs >> 2)
		    && *blk != QT_TREEOFF) {
			put_free_dqblk(info, buf, *blk);
			*blk = 0;
		} else {
			ret = write_blk(info, *blk, buf);
			if (ret < 0)
				printk(KERN_ERR "VFS: Can't write quota tree "
				  "block %u.\n", *blk);
		}
	}
out_buf:
496
	kfree(buf);
497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514
	return ret;
}

/* Delete dquot from tree */
int qtree_delete_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
{
	uint tmp = QT_TREEOFF;

	if (!dquot->dq_off)	/* Even not allocated? */
		return 0;
	return remove_tree(info, dquot, &tmp, 0);
}
EXPORT_SYMBOL(qtree_delete_dquot);

/* Find entry in block */
static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
				 struct dquot *dquot, uint blk)
{
515
	char *buf = getdqbuf(info->dqi_usable_bs);
516 517 518 519 520 521 522 523 524 525 526
	loff_t ret = 0;
	int i;
	char *ddquot;

	if (!buf)
		return -ENOMEM;
	ret = read_blk(info, blk, buf);
	if (ret < 0) {
		printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
		goto out_buf;
	}
J
Jan Kara 已提交
527 528 529 530 531 532
	ddquot = buf + sizeof(struct qt_disk_dqdbheader);
	for (i = 0; i < qtree_dqstr_in_blk(info); i++) {
		if (info->dqi_ops->is_id(ddquot, dquot))
			break;
		ddquot += info->dqi_entry_size;
	}
533 534 535 536 537 538 539 540 541 542
	if (i == qtree_dqstr_in_blk(info)) {
		printk(KERN_ERR "VFS: Quota for id %u referenced "
		  "but not present.\n", dquot->dq_id);
		ret = -EIO;
		goto out_buf;
	} else {
		ret = (blk << info->dqi_blocksize_bits) + sizeof(struct
		  qt_disk_dqdbheader) + i * info->dqi_entry_size;
	}
out_buf:
543
	kfree(buf);
544 545 546 547 548 549 550
	return ret;
}

/* Find entry for given id in the tree */
static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
				struct dquot *dquot, uint blk, int depth)
{
551
	char *buf = getdqbuf(info->dqi_usable_bs);
552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570
	loff_t ret = 0;
	__le32 *ref = (__le32 *)buf;

	if (!buf)
		return -ENOMEM;
	ret = read_blk(info, blk, buf);
	if (ret < 0) {
		printk(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
		goto out_buf;
	}
	ret = 0;
	blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
	if (!blk)	/* No reference? */
		goto out_buf;
	if (depth < info->dqi_qtree_depth - 1)
		ret = find_tree_dqentry(info, dquot, blk, depth+1);
	else
		ret = find_block_dqentry(info, dquot, blk);
out_buf:
571
	kfree(buf);
572 573 574 575 576 577 578 579 580 581 582 583 584 585 586
	return ret;
}

/* Find entry for given id in the tree - wrapper function */
static inline loff_t find_dqentry(struct qtree_mem_dqinfo *info,
				  struct dquot *dquot)
{
	return find_tree_dqentry(info, dquot, QT_TREEOFF, 0);
}

int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
{
	int type = dquot->dq_type;
	struct super_block *sb = dquot->dq_sb;
	loff_t offset;
587
	char *ddquot;
588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614
	int ret = 0;

#ifdef __QUOTA_QT_PARANOIA
	/* Invalidated quota? */
	if (!sb_dqopt(dquot->dq_sb)->files[type]) {
		printk(KERN_ERR "VFS: Quota invalidated while reading!\n");
		return -EIO;
	}
#endif
	/* Do we know offset of the dquot entry in the quota file? */
	if (!dquot->dq_off) {
		offset = find_dqentry(info, dquot);
		if (offset <= 0) {	/* Entry not present? */
			if (offset < 0)
				printk(KERN_ERR "VFS: Can't read quota "
				  "structure for id %u.\n", dquot->dq_id);
			dquot->dq_off = 0;
			set_bit(DQ_FAKE_B, &dquot->dq_flags);
			memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
			ret = offset;
			goto out;
		}
		dquot->dq_off = offset;
	}
	ddquot = getdqbuf(info->dqi_entry_size);
	if (!ddquot)
		return -ENOMEM;
615 616
	ret = sb->s_op->quota_read(sb, type, ddquot, info->dqi_entry_size,
				   dquot->dq_off);
617 618 619 620 621 622 623
	if (ret != info->dqi_entry_size) {
		if (ret >= 0)
			ret = -EIO;
		printk(KERN_ERR "VFS: Error while reading quota "
				"structure for id %u.\n", dquot->dq_id);
		set_bit(DQ_FAKE_B, &dquot->dq_flags);
		memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
624
		kfree(ddquot);
625 626 627 628 629 630 631 632 633 634
		goto out;
	}
	spin_lock(&dq_data_lock);
	info->dqi_ops->disk2mem_dqblk(dquot, ddquot);
	if (!dquot->dq_dqb.dqb_bhardlimit &&
	    !dquot->dq_dqb.dqb_bsoftlimit &&
	    !dquot->dq_dqb.dqb_ihardlimit &&
	    !dquot->dq_dqb.dqb_isoftlimit)
		set_bit(DQ_FAKE_B, &dquot->dq_flags);
	spin_unlock(&dq_data_lock);
635
	kfree(ddquot);
636 637 638 639 640 641 642 643 644 645
out:
	dqstats.reads++;
	return ret;
}
EXPORT_SYMBOL(qtree_read_dquot);

/* Check whether dquot should not be deleted. We know we are
 * the only one operating on dquot (thanks to dq_lock) */
int qtree_release_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
{
J
Jan Kara 已提交
646 647
	if (test_bit(DQ_FAKE_B, &dquot->dq_flags) &&
	    !(dquot->dq_dqb.dqb_curinodes | dquot->dq_dqb.dqb_curspace))
648 649 650 651
		return qtree_delete_dquot(info, dquot);
	return 0;
}
EXPORT_SYMBOL(qtree_release_dquot);