bmap.c 15.1 KB
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 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
/*
 * bmap.c - NILFS block mapping.
 *
 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <koji@osrg.net>.
 */

#include <linux/fs.h>
#include <linux/string.h>
#include <linux/errno.h>
#include "nilfs.h"
#include "bmap.h"
#include "btree.h"
#include "direct.h"
#include "btnode.h"
#include "mdt.h"
#include "dat.h"
#include "alloc.h"

struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
{
	struct the_nilfs *nilfs = bmap->b_inode->i_sb->s_fs_info;

	return nilfs->ns_dat;
}

static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
				     const char *fname, int err)
{
	struct inode *inode = bmap->b_inode;

	if (err == -EINVAL) {
		nilfs_error(inode->i_sb, fname,
			    "broken bmap (inode number=%lu)\n", inode->i_ino);
		err = -EIO;
	}
	return err;
}

/**
 * nilfs_bmap_lookup_at_level - find a data block or node block
 * @bmap: bmap
 * @key: key
 * @level: level
 * @ptrp: place to store the value associated to @key
 *
 * Description: nilfs_bmap_lookup_at_level() finds a record whose key
 * matches @key in the block at @level of the bmap.
 *
 * Return Value: On success, 0 is returned and the record associated with @key
 * is stored in the place pointed by @ptrp. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - A record associated with @key does not exist.
 */
int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
			       __u64 *ptrp)
{
	sector_t blocknr;
	int ret;

	down_read(&bmap->b_sem);
	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
	if (ret < 0) {
		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
		goto out;
	}
	if (NILFS_BMAP_USE_VBN(bmap)) {
		ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
					  &blocknr);
		if (!ret)
			*ptrp = blocknr;
	}

 out:
	up_read(&bmap->b_sem);
	return ret;
}

int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
			     unsigned maxblocks)
{
	int ret;

	down_read(&bmap->b_sem);
	ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
	up_read(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
{
	__u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
	__u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
	int ret, n;

	if (bmap->b_ops->bop_check_insert != NULL) {
		ret = bmap->b_ops->bop_check_insert(bmap, key);
		if (ret > 0) {
			n = bmap->b_ops->bop_gather_data(
				bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
			if (n < 0)
				return n;
			ret = nilfs_btree_convert_and_insert(
				bmap, key, ptr, keys, ptrs, n);
			if (ret == 0)
				bmap->b_u.u_flags |= NILFS_BMAP_LARGE;

			return ret;
		} else if (ret < 0)
			return ret;
	}

	return bmap->b_ops->bop_insert(bmap, key, ptr);
}

/**
 * nilfs_bmap_insert - insert a new key-record pair into a bmap
 * @bmap: bmap
 * @key: key
 * @rec: record
 *
 * Description: nilfs_bmap_insert() inserts the new key-record pair specified
 * by @key and @rec into @bmap.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-EEXIST - A record associated with @key already exist.
 */
int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = nilfs_bmap_do_insert(bmap, key, rec);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
{
	__u64 keys[NILFS_BMAP_LARGE_LOW + 1];
	__u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
	int ret, n;

	if (bmap->b_ops->bop_check_delete != NULL) {
		ret = bmap->b_ops->bop_check_delete(bmap, key);
		if (ret > 0) {
			n = bmap->b_ops->bop_gather_data(
				bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
			if (n < 0)
				return n;
			ret = nilfs_direct_delete_and_convert(
				bmap, key, keys, ptrs, n);
			if (ret == 0)
				bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;

			return ret;
		} else if (ret < 0)
			return ret;
	}

	return bmap->b_ops->bop_delete(bmap, key);
}

/**
 * nilfs_bmap_seek_key - seek a valid entry and return its key
 * @bmap: bmap struct
 * @start: start key number
 * @keyp: place to store valid key
 *
 * Description: nilfs_bmap_seek_key() seeks a valid key on @bmap
 * starting from @start, and stores it to @keyp if found.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - No valid entry was found
 */
int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp)
{
	int ret;

	down_read(&bmap->b_sem);
	ret = bmap->b_ops->bop_seek_key(bmap, start, keyp);
	up_read(&bmap->b_sem);

	if (ret < 0)
		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
	return ret;
}

int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp)
{
	int ret;

	down_read(&bmap->b_sem);
	ret = bmap->b_ops->bop_last_key(bmap, keyp);
	up_read(&bmap->b_sem);

	if (ret < 0)
		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
	return ret;
}

/**
 * nilfs_bmap_delete - delete a key-record pair from a bmap
 * @bmap: bmap
 * @key: key
 *
 * Description: nilfs_bmap_delete() deletes the key-record pair specified by
 * @key from @bmap.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 *
 * %-ENOENT - A record associated with @key does not exist.
 */
int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = nilfs_bmap_do_delete(bmap, key);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, __u64 key)
{
	__u64 lastkey;
	int ret;

	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
	if (ret < 0) {
		if (ret == -ENOENT)
			ret = 0;
		return ret;
	}

	while (key <= lastkey) {
		ret = nilfs_bmap_do_delete(bmap, lastkey);
		if (ret < 0)
			return ret;
		ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
		if (ret < 0) {
			if (ret == -ENOENT)
				ret = 0;
			return ret;
		}
	}
	return 0;
}

/**
 * nilfs_bmap_truncate - truncate a bmap to a specified key
 * @bmap: bmap
 * @key: key
 *
 * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
 * greater than or equal to @key from @bmap.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = nilfs_bmap_do_truncate(bmap, key);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

/**
 * nilfs_bmap_clear - free resources a bmap holds
 * @bmap: bmap
 *
 * Description: nilfs_bmap_clear() frees resources associated with @bmap.
 */
void nilfs_bmap_clear(struct nilfs_bmap *bmap)
{
	down_write(&bmap->b_sem);
	if (bmap->b_ops->bop_clear != NULL)
		bmap->b_ops->bop_clear(bmap);
	up_write(&bmap->b_sem);
}

/**
 * nilfs_bmap_propagate - propagate dirty state
 * @bmap: bmap
 * @bh: buffer head
 *
 * Description: nilfs_bmap_propagate() marks the buffers that directly or
 * indirectly refer to the block specified by @bh dirty.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = bmap->b_ops->bop_propagate(bmap, bh);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

/**
 * nilfs_bmap_lookup_dirty_buffers -
 * @bmap: bmap
 * @listp: pointer to buffer head list
 */
void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
				     struct list_head *listp)
{
	if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
		bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
}

/**
 * nilfs_bmap_assign - assign a new block number to a block
 * @bmap: bmap
 * @bhp: pointer to buffer head
 * @blocknr: block number
 * @binfo: block information
 *
 * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
 * buffer specified by @bh.
 *
 * Return Value: On success, 0 is returned and the buffer head of a newly
 * create buffer and the block information associated with the buffer are
 * stored in the place pointed by @bh and @binfo, respectively. On error, one
 * of the following negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_bmap_assign(struct nilfs_bmap *bmap,
		      struct buffer_head **bh,
		      unsigned long blocknr,
		      union nilfs_binfo *binfo)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

/**
 * nilfs_bmap_mark - mark block dirty
 * @bmap: bmap
 * @key: key
 * @level: level
 *
 * Description: nilfs_bmap_mark() marks the block specified by @key and @level
 * as dirty.
 *
 * Return Value: On success, 0 is returned. On error, one of the following
 * negative error codes is returned.
 *
 * %-EIO - I/O error.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
{
	int ret;

	if (bmap->b_ops->bop_mark == NULL)
		return 0;

	down_write(&bmap->b_sem);
	ret = bmap->b_ops->bop_mark(bmap, key, level);
	up_write(&bmap->b_sem);

	return nilfs_bmap_convert_error(bmap, __func__, ret);
}

/**
 * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
 * @bmap: bmap
 *
 * Description: nilfs_test_and_clear() is the atomic operation to test and
 * clear the dirty state of @bmap.
 *
 * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
 */
int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
{
	int ret;

	down_write(&bmap->b_sem);
	ret = nilfs_bmap_dirty(bmap);
	nilfs_bmap_clear_dirty(bmap);
	up_write(&bmap->b_sem);
	return ret;
}


/*
 * Internal use only
 */
__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
			      const struct buffer_head *bh)
{
	struct buffer_head *pbh;
	__u64 key;

	key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
					 bmap->b_inode->i_blkbits);
	for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
		key++;

	return key;
}

__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
{
	__s64 diff;

	diff = key - bmap->b_last_allocated_key;
	if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
	    (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
	    (bmap->b_last_allocated_ptr + diff > 0))
		return bmap->b_last_allocated_ptr + diff;
	else
		return NILFS_BMAP_INVALID_PTR;
}

#define NILFS_BMAP_GROUP_DIV	8
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
{
	struct inode *dat = nilfs_bmap_get_dat(bmap);
	unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
	unsigned long group = bmap->b_inode->i_ino / entries_per_group;

	return group * entries_per_group +
		(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
		(entries_per_group / NILFS_BMAP_GROUP_DIV);
}

static struct lock_class_key nilfs_bmap_dat_lock_key;
static struct lock_class_key nilfs_bmap_mdt_lock_key;

/**
 * nilfs_bmap_read - read a bmap from an inode
 * @bmap: bmap
 * @raw_inode: on-disk inode
 *
 * Description: nilfs_bmap_read() initializes the bmap @bmap.
 *
 * Return Value: On success, 0 is returned. On error, the following negative
 * error code is returned.
 *
 * %-ENOMEM - Insufficient amount of memory available.
 */
int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
	if (raw_inode == NULL)
		memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
	else
		memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);

	init_rwsem(&bmap->b_sem);
	bmap->b_state = 0;
	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
	switch (bmap->b_inode->i_ino) {
	case NILFS_DAT_INO:
		bmap->b_ptr_type = NILFS_BMAP_PTR_P;
		bmap->b_last_allocated_key = 0;
		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
		break;
	case NILFS_CPFILE_INO:
	case NILFS_SUFILE_INO:
		bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
		bmap->b_last_allocated_key = 0;
		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
		break;
	case NILFS_IFILE_INO:
		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
		/* Fall through */
	default:
		bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
		bmap->b_last_allocated_key = 0;
		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
		break;
	}

	return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
		nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
}

/**
 * nilfs_bmap_write - write back a bmap to an inode
 * @bmap: bmap
 * @raw_inode: on-disk inode
 *
 * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
 */
void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
{
	down_write(&bmap->b_sem);
	memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
	       NILFS_INODE_BMAP_SIZE * sizeof(__le64));
	if (bmap->b_inode->i_ino == NILFS_DAT_INO)
		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;

	up_write(&bmap->b_sem);
}

void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
{
	memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
	init_rwsem(&bmap->b_sem);
	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
	bmap->b_ptr_type = NILFS_BMAP_PTR_U;
	bmap->b_last_allocated_key = 0;
	bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
	bmap->b_state = 0;
	nilfs_btree_init_gc(bmap);
}

void nilfs_bmap_save(const struct nilfs_bmap *bmap,
		     struct nilfs_bmap_store *store)
{
	memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
	store->last_allocated_key = bmap->b_last_allocated_key;
	store->last_allocated_ptr = bmap->b_last_allocated_ptr;
	store->state = bmap->b_state;
}

void nilfs_bmap_restore(struct nilfs_bmap *bmap,
			const struct nilfs_bmap_store *store)
{
	memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
	bmap->b_last_allocated_key = store->last_allocated_key;
	bmap->b_last_allocated_ptr = store->last_allocated_ptr;
	bmap->b_state = store->state;
}