the_nilfs.c 23.1 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
/*
 * the_nilfs.c - the_nilfs shared structure.
 *
 * Copyright (C) 2005-2008 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 Ryusuke Konishi <ryusuke@osrg.net>
 *
 */

#include <linux/buffer_head.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
28
#include <linux/crc32.h>
29 30 31 32 33 34 35 36
#include "nilfs.h"
#include "segment.h"
#include "alloc.h"
#include "cpfile.h"
#include "sufile.h"
#include "dat.h"
#include "segbuf.h"

37 38 39 40

static LIST_HEAD(nilfs_objects);
static DEFINE_SPINLOCK(nilfs_lock);

41 42
static int nilfs_valid_sb(struct nilfs_super_block *sbp);

43 44 45 46 47 48 49
void nilfs_set_last_segment(struct the_nilfs *nilfs,
			    sector_t start_blocknr, u64 seq, __u64 cno)
{
	spin_lock(&nilfs->ns_last_segment_lock);
	nilfs->ns_last_pseg = start_blocknr;
	nilfs->ns_last_seq = seq;
	nilfs->ns_last_cno = cno;
50 51 52 53 54 55 56 57 58 59

	if (!nilfs_sb_dirty(nilfs)) {
		if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
			goto stay_cursor;

		set_nilfs_sb_dirty(nilfs);
	}
	nilfs->ns_prev_seq = nilfs->ns_last_seq;

 stay_cursor:
60 61 62 63 64 65 66 67 68 69 70 71 72
	spin_unlock(&nilfs->ns_last_segment_lock);
}

/**
 * alloc_nilfs - allocate the_nilfs structure
 * @bdev: block device to which the_nilfs is related
 *
 * alloc_nilfs() allocates memory for the_nilfs and
 * initializes its reference count and locks.
 *
 * Return Value: On success, pointer to the_nilfs is returned.
 * On error, NULL is returned.
 */
73
static struct the_nilfs *alloc_nilfs(struct block_device *bdev)
74 75 76 77 78 79 80 81 82 83 84
{
	struct the_nilfs *nilfs;

	nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
	if (!nilfs)
		return NULL;

	nilfs->ns_bdev = bdev;
	atomic_set(&nilfs->ns_count, 1);
	atomic_set(&nilfs->ns_ndirtyblks, 0);
	init_rwsem(&nilfs->ns_sem);
85
	init_rwsem(&nilfs->ns_super_sem);
86
	mutex_init(&nilfs->ns_mount_mutex);
87
	init_rwsem(&nilfs->ns_writer_sem);
88
	INIT_LIST_HEAD(&nilfs->ns_list);
89 90 91 92 93 94 95 96
	INIT_LIST_HEAD(&nilfs->ns_supers);
	spin_lock_init(&nilfs->ns_last_segment_lock);
	nilfs->ns_gc_inodes_h = NULL;
	init_rwsem(&nilfs->ns_segctor_sem);

	return nilfs;
}

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
/**
 * find_or_create_nilfs - find or create nilfs object
 * @bdev: block device to which the_nilfs is related
 *
 * find_nilfs() looks up an existent nilfs object created on the
 * device and gets the reference count of the object.  If no nilfs object
 * is found on the device, a new nilfs object is allocated.
 *
 * Return Value: On success, pointer to the nilfs object is returned.
 * On error, NULL is returned.
 */
struct the_nilfs *find_or_create_nilfs(struct block_device *bdev)
{
	struct the_nilfs *nilfs, *new = NULL;

 retry:
	spin_lock(&nilfs_lock);
	list_for_each_entry(nilfs, &nilfs_objects, ns_list) {
		if (nilfs->ns_bdev == bdev) {
			get_nilfs(nilfs);
			spin_unlock(&nilfs_lock);
			if (new)
				put_nilfs(new);
			return nilfs; /* existing object */
		}
	}
	if (new) {
		list_add_tail(&new->ns_list, &nilfs_objects);
		spin_unlock(&nilfs_lock);
		return new; /* new object */
	}
	spin_unlock(&nilfs_lock);

	new = alloc_nilfs(bdev);
	if (new)
		goto retry;
	return NULL; /* insufficient memory */
}

136 137 138 139 140 141 142 143 144
/**
 * put_nilfs - release a reference to the_nilfs
 * @nilfs: the_nilfs structure to be released
 *
 * put_nilfs() decrements a reference counter of the_nilfs.
 * If the reference count reaches zero, the_nilfs is freed.
 */
void put_nilfs(struct the_nilfs *nilfs)
{
145 146 147
	spin_lock(&nilfs_lock);
	if (!atomic_dec_and_test(&nilfs->ns_count)) {
		spin_unlock(&nilfs_lock);
148
		return;
149 150 151 152
	}
	list_del_init(&nilfs->ns_list);
	spin_unlock(&nilfs_lock);

153
	/*
154
	 * Increment of ns_count never occurs below because the caller
155 156 157
	 * of get_nilfs() holds at least one reference to the_nilfs.
	 * Thus its exclusion control is not required here.
	 */
158

159 160 161 162 163 164 165 166 167
	might_sleep();
	if (nilfs_loaded(nilfs)) {
		nilfs_mdt_destroy(nilfs->ns_sufile);
		nilfs_mdt_destroy(nilfs->ns_cpfile);
		nilfs_mdt_destroy(nilfs->ns_dat);
		nilfs_mdt_destroy(nilfs->ns_gc_dat);
	}
	if (nilfs_init(nilfs)) {
		nilfs_destroy_gccache(nilfs);
168 169
		brelse(nilfs->ns_sbh[0]);
		brelse(nilfs->ns_sbh[1]);
170 171 172 173
	}
	kfree(nilfs);
}

174
static int nilfs_load_super_root(struct the_nilfs *nilfs, sector_t sr_block)
175 176 177
{
	struct buffer_head *bh_sr;
	struct nilfs_super_root *raw_sr;
178
	struct nilfs_super_block **sbp = nilfs->ns_sbp;
179 180 181 182
	unsigned dat_entry_size, segment_usage_size, checkpoint_size;
	unsigned inode_size;
	int err;

183
	err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
184 185 186 187
	if (unlikely(err))
		return err;

	down_read(&nilfs->ns_sem);
188 189 190
	dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
	checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
	segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
191 192 193 194 195
	up_read(&nilfs->ns_sem);

	inode_size = nilfs->ns_inode_size;

	err = -ENOMEM;
196
	nilfs->ns_dat = nilfs_dat_new(nilfs, dat_entry_size);
197 198 199
	if (unlikely(!nilfs->ns_dat))
		goto failed;

200
	nilfs->ns_gc_dat = nilfs_dat_new(nilfs, dat_entry_size);
201 202 203
	if (unlikely(!nilfs->ns_gc_dat))
		goto failed_dat;

204
	nilfs->ns_cpfile = nilfs_cpfile_new(nilfs, checkpoint_size);
205 206 207
	if (unlikely(!nilfs->ns_cpfile))
		goto failed_gc_dat;

208
	nilfs->ns_sufile = nilfs_sufile_new(nilfs, segment_usage_size);
209 210 211 212 213
	if (unlikely(!nilfs->ns_sufile))
		goto failed_cpfile;

	nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);

214 215
	err = nilfs_dat_read(nilfs->ns_dat, (void *)bh_sr->b_data +
			     NILFS_SR_DAT_OFFSET(inode_size));
216 217 218
	if (unlikely(err))
		goto failed_sufile;

219 220
	err = nilfs_cpfile_read(nilfs->ns_cpfile, (void *)bh_sr->b_data +
				NILFS_SR_CPFILE_OFFSET(inode_size));
221 222 223
	if (unlikely(err))
		goto failed_sufile;

224 225
	err = nilfs_sufile_read(nilfs->ns_sufile, (void *)bh_sr->b_data +
				NILFS_SR_SUFILE_OFFSET(inode_size));
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
	if (unlikely(err))
		goto failed_sufile;

	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
	nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);

 failed:
	brelse(bh_sr);
	return err;

 failed_sufile:
	nilfs_mdt_destroy(nilfs->ns_sufile);

 failed_cpfile:
	nilfs_mdt_destroy(nilfs->ns_cpfile);

 failed_gc_dat:
	nilfs_mdt_destroy(nilfs->ns_gc_dat);

 failed_dat:
	nilfs_mdt_destroy(nilfs->ns_dat);
	goto failed;
}

static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
{
	memset(ri, 0, sizeof(*ri));
	INIT_LIST_HEAD(&ri->ri_used_segments);
}

static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
{
	nilfs_dispose_segment_list(&ri->ri_used_segments);
}

261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279
/**
 * nilfs_store_log_cursor - load log cursor from a super block
 * @nilfs: nilfs object
 * @sbp: buffer storing super block to be read
 *
 * nilfs_store_log_cursor() reads the last position of the log
 * containing a super root from a given super block, and initializes
 * relevant information on the nilfs object preparatory for log
 * scanning and recovery.
 */
static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
				  struct nilfs_super_block *sbp)
{
	int ret = 0;

	nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
	nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
	nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);

280
	nilfs->ns_prev_seq = nilfs->ns_last_seq;
281 282 283 284 285 286 287 288 289 290 291
	nilfs->ns_seg_seq = nilfs->ns_last_seq;
	nilfs->ns_segnum =
		nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
	nilfs->ns_cno = nilfs->ns_last_cno + 1;
	if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
		printk(KERN_ERR "NILFS invalid last segment number.\n");
		ret = -EINVAL;
	}
	return ret;
}

292 293 294 295 296 297 298 299 300 301 302 303 304 305
/**
 * load_nilfs - load and recover the nilfs
 * @nilfs: the_nilfs structure to be released
 * @sbi: nilfs_sb_info used to recover past segment
 *
 * load_nilfs() searches and load the latest super root,
 * attaches the last segment, and does recovery if needed.
 * The caller must call this exclusively for simultaneous mounts.
 */
int load_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi)
{
	struct nilfs_recovery_info ri;
	unsigned int s_flags = sbi->s_super->s_flags;
	int really_read_only = bdev_read_only(nilfs->ns_bdev);
306
	int valid_fs = nilfs_valid_fs(nilfs);
307
	int err;
308

309 310 311 312 313 314 315 316
	if (nilfs_loaded(nilfs)) {
		if (valid_fs ||
		    ((s_flags & MS_RDONLY) && nilfs_test_opt(sbi, NORECOVERY)))
			return 0;
		printk(KERN_ERR "NILFS: the filesystem is in an incomplete "
		       "recovery state.\n");
		return -EINVAL;
	}
317

318 319 320 321 322 323 324
	if (!valid_fs) {
		printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
		if (s_flags & MS_RDONLY) {
			printk(KERN_INFO "NILFS: INFO: recovery "
			       "required for readonly filesystem.\n");
			printk(KERN_INFO "NILFS: write access will "
			       "be enabled during recovery.\n");
325 326 327
		}
	}

328 329
	nilfs_init_recovery_info(&ri);

330
	err = nilfs_search_super_root(nilfs, &ri);
331
	if (unlikely(err)) {
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
		struct nilfs_super_block **sbp = nilfs->ns_sbp;
		int blocksize;

		if (err != -EINVAL)
			goto scan_error;

		if (!nilfs_valid_sb(sbp[1])) {
			printk(KERN_WARNING
			       "NILFS warning: unable to fall back to spare"
			       "super block\n");
			goto scan_error;
		}
		printk(KERN_INFO
		       "NILFS: try rollback from an earlier position\n");

		/*
		 * restore super block with its spare and reconfigure
		 * relevant states of the nilfs object.
		 */
		memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
		nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
		nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);

		/* verify consistency between two super blocks */
		blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
		if (blocksize != nilfs->ns_blocksize) {
			printk(KERN_WARNING
			       "NILFS warning: blocksize differs between "
			       "two super blocks (%d != %d)\n",
			       blocksize, nilfs->ns_blocksize);
			goto scan_error;
		}

		err = nilfs_store_log_cursor(nilfs, sbp[0]);
		if (err)
			goto scan_error;

		/* drop clean flag to allow roll-forward and recovery */
		nilfs->ns_mount_state &= ~NILFS_VALID_FS;
		valid_fs = 0;

		err = nilfs_search_super_root(nilfs, &ri);
		if (err)
			goto scan_error;
376 377
	}

378
	err = nilfs_load_super_root(nilfs, ri.ri_super_root);
379 380 381 382 383
	if (unlikely(err)) {
		printk(KERN_ERR "NILFS: error loading super root.\n");
		goto failed;
	}

384 385 386 387
	if (valid_fs)
		goto skip_recovery;

	if (s_flags & MS_RDONLY) {
388 389 390 391 392
		if (nilfs_test_opt(sbi, NORECOVERY)) {
			printk(KERN_INFO "NILFS: norecovery option specified. "
			       "skipping roll-forward recovery\n");
			goto skip_recovery;
		}
393 394 395 396 397
		if (really_read_only) {
			printk(KERN_ERR "NILFS: write access "
			       "unavailable, cannot proceed.\n");
			err = -EROFS;
			goto failed_unload;
398
		}
399
		sbi->s_super->s_flags &= ~MS_RDONLY;
400 401 402 403 404
	} else if (nilfs_test_opt(sbi, NORECOVERY)) {
		printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
		       "option was specified for a read/write mount\n");
		err = -EINVAL;
		goto failed_unload;
405 406
	}

407
	err = nilfs_salvage_orphan_logs(nilfs, sbi, &ri);
408 409 410 411
	if (err)
		goto failed_unload;

	down_write(&nilfs->ns_sem);
412 413
	nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
	err = nilfs_cleanup_super(sbi);
414 415 416 417 418 419
	up_write(&nilfs->ns_sem);

	if (err) {
		printk(KERN_ERR "NILFS: failed to update super block. "
		       "recovery unfinished.\n");
		goto failed_unload;
420
	}
421
	printk(KERN_INFO "NILFS: recovery complete.\n");
422

423
 skip_recovery:
424
	set_nilfs_loaded(nilfs);
425 426 427 428
	nilfs_clear_recovery_info(&ri);
	sbi->s_super->s_flags = s_flags;
	return 0;

429 430 431 432
 scan_error:
	printk(KERN_ERR "NILFS: error searching super root.\n");
	goto failed;

433 434 435 436
 failed_unload:
	nilfs_mdt_destroy(nilfs->ns_cpfile);
	nilfs_mdt_destroy(nilfs->ns_sufile);
	nilfs_mdt_destroy(nilfs->ns_dat);
437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454

 failed:
	nilfs_clear_recovery_info(&ri);
	sbi->s_super->s_flags = s_flags;
	return err;
}

static unsigned long long nilfs_max_size(unsigned int blkbits)
{
	unsigned int max_bits;
	unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */

	max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
	if (max_bits < 64)
		res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
	return res;
}

455 456
static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
				   struct nilfs_super_block *sbp)
457 458 459 460 461 462 463 464 465 466
{
	if (le32_to_cpu(sbp->s_rev_level) != NILFS_CURRENT_REV) {
		printk(KERN_ERR "NILFS: revision mismatch "
		       "(superblock rev.=%d.%d, current rev.=%d.%d). "
		       "Please check the version of mkfs.nilfs.\n",
		       le32_to_cpu(sbp->s_rev_level),
		       le16_to_cpu(sbp->s_minor_rev_level),
		       NILFS_CURRENT_REV, NILFS_MINOR_REV);
		return -EINVAL;
	}
467 468 469 470
	nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
	if (nilfs->ns_sbsize > BLOCK_SIZE)
		return -EINVAL;

471 472 473 474 475
	nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
	nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);

	nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
	if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
476
		printk(KERN_ERR "NILFS: too short segment.\n");
477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
		return -EINVAL;
	}

	nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
	nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
	nilfs->ns_r_segments_percentage =
		le32_to_cpu(sbp->s_r_segments_percentage);
	nilfs->ns_nrsvsegs =
		max_t(unsigned long, NILFS_MIN_NRSVSEGS,
		      DIV_ROUND_UP(nilfs->ns_nsegments *
				   nilfs->ns_r_segments_percentage, 100));
	nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
	return 0;
}

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
static int nilfs_valid_sb(struct nilfs_super_block *sbp)
{
	static unsigned char sum[4];
	const int sumoff = offsetof(struct nilfs_super_block, s_sum);
	size_t bytes;
	u32 crc;

	if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
		return 0;
	bytes = le16_to_cpu(sbp->s_bytes);
	if (bytes > BLOCK_SIZE)
		return 0;
	crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
		       sumoff);
	crc = crc32_le(crc, sum, 4);
	crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
		       bytes - sumoff - 4);
	return crc == le32_to_cpu(sbp->s_sum);
}

static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
{
	return offset < ((le64_to_cpu(sbp->s_nsegments) *
			  le32_to_cpu(sbp->s_blocks_per_segment)) <<
			 (le32_to_cpu(sbp->s_log_block_size) + 10));
}

static void nilfs_release_super_block(struct the_nilfs *nilfs)
{
	int i;

	for (i = 0; i < 2; i++) {
		if (nilfs->ns_sbp[i]) {
			brelse(nilfs->ns_sbh[i]);
			nilfs->ns_sbh[i] = NULL;
			nilfs->ns_sbp[i] = NULL;
		}
	}
}

void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
{
	brelse(nilfs->ns_sbh[0]);
	nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
	nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
	nilfs->ns_sbh[1] = NULL;
	nilfs->ns_sbp[1] = NULL;
}

void nilfs_swap_super_block(struct the_nilfs *nilfs)
{
	struct buffer_head *tsbh = nilfs->ns_sbh[0];
	struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];

	nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
	nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
	nilfs->ns_sbh[1] = tsbh;
	nilfs->ns_sbp[1] = tsbp;
}

static int nilfs_load_super_block(struct the_nilfs *nilfs,
				  struct super_block *sb, int blocksize,
				  struct nilfs_super_block **sbpp)
{
	struct nilfs_super_block **sbp = nilfs->ns_sbp;
	struct buffer_head **sbh = nilfs->ns_sbh;
	u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
	int valid[2], swp = 0;

	sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
					&sbh[0]);
	sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);

	if (!sbp[0]) {
		if (!sbp[1]) {
			printk(KERN_ERR "NILFS: unable to read superblock\n");
			return -EIO;
		}
		printk(KERN_WARNING
		       "NILFS warning: unable to read primary superblock\n");
	} else if (!sbp[1])
		printk(KERN_WARNING
		       "NILFS warning: unable to read secondary superblock\n");

576 577 578 579
	/*
	 * Compare two super blocks and set 1 in swp if the secondary
	 * super block is valid and newer.  Otherwise, set 0 in swp.
	 */
580 581
	valid[0] = nilfs_valid_sb(sbp[0]);
	valid[1] = nilfs_valid_sb(sbp[1]);
582 583 584
	swp = valid[1] && (!valid[0] ||
			   le64_to_cpu(sbp[1]->s_last_cno) >
			   le64_to_cpu(sbp[0]->s_last_cno));
585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604

	if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
		brelse(sbh[1]);
		sbh[1] = NULL;
		sbp[1] = NULL;
		swp = 0;
	}
	if (!valid[swp]) {
		nilfs_release_super_block(nilfs);
		printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
		       sb->s_id);
		return -EINVAL;
	}

	if (swp) {
		printk(KERN_WARNING "NILFS warning: broken superblock. "
		       "using spare superblock.\n");
		nilfs_swap_super_block(nilfs);
	}

605 606
	nilfs->ns_sbwcount = 0;
	nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
607 608 609 610 611
	nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
	*sbpp = sbp[0];
	return 0;
}

612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636
/**
 * init_nilfs - initialize a NILFS instance.
 * @nilfs: the_nilfs structure
 * @sbi: nilfs_sb_info
 * @sb: super block
 * @data: mount options
 *
 * init_nilfs() performs common initialization per block device (e.g.
 * reading the super block, getting disk layout information, initializing
 * shared fields in the_nilfs). It takes on some portion of the jobs
 * typically done by a fill_super() routine. This division arises from
 * the nature that multiple NILFS instances may be simultaneously
 * mounted on a device.
 * For multiple mounts on the same device, only the first mount
 * invokes these tasks.
 *
 * Return Value: On success, 0 is returned. On error, a negative error
 * code is returned.
 */
int init_nilfs(struct the_nilfs *nilfs, struct nilfs_sb_info *sbi, char *data)
{
	struct super_block *sb = sbi->s_super;
	struct nilfs_super_block *sbp;
	struct backing_dev_info *bdi;
	int blocksize;
637
	int err;
638 639 640 641

	down_write(&nilfs->ns_sem);
	if (nilfs_init(nilfs)) {
		/* Load values from existing the_nilfs */
642
		sbp = nilfs->ns_sbp[0];
643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
		err = nilfs_store_magic_and_option(sb, sbp, data);
		if (err)
			goto out;

		blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
		if (sb->s_blocksize != blocksize &&
		    !sb_set_blocksize(sb, blocksize)) {
			printk(KERN_ERR "NILFS: blocksize %d unfit to device\n",
			       blocksize);
			err = -EINVAL;
		}
		sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
		goto out;
	}

658 659 660
	blocksize = sb_min_blocksize(sb, BLOCK_SIZE);
	if (!blocksize) {
		printk(KERN_ERR "NILFS: unable to set blocksize\n");
661 662 663
		err = -EINVAL;
		goto out;
	}
664 665 666 667
	err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
	if (err)
		goto out;

668 669 670 671 672 673
	err = nilfs_store_magic_and_option(sb, sbp, data);
	if (err)
		goto failed_sbh;

	blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
	if (sb->s_blocksize != blocksize) {
674
		int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
675 676 677 678 679 680

		if (blocksize < hw_blocksize) {
			printk(KERN_ERR
			       "NILFS: blocksize %d too small for device "
			       "(sector-size = %d).\n",
			       blocksize, hw_blocksize);
681
			err = -EINVAL;
682 683 684 685 686 687 688
			goto failed_sbh;
		}
		nilfs_release_super_block(nilfs);
		sb_set_blocksize(sb, blocksize);

		err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
		if (err)
689 690 691 692 693
			goto out;
			/* not failed_sbh; sbh is released automatically
			   when reloading fails. */
	}
	nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
694
	nilfs->ns_blocksize = blocksize;
695

696
	err = nilfs_store_disk_layout(nilfs, sbp);
697 698 699 700 701 702 703
	if (err)
		goto failed_sbh;

	sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);

	nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);

704
	bdi = nilfs->ns_bdev->bd_inode->i_mapping->backing_dev_info;
705 706
	nilfs->ns_bdi = bdi ? : &default_backing_dev_info;

707 708
	err = nilfs_store_log_cursor(nilfs, sbp);
	if (err)
709 710 711 712 713 714 715 716 717 718 719 720 721 722
		goto failed_sbh;

	/* Initialize gcinode cache */
	err = nilfs_init_gccache(nilfs);
	if (err)
		goto failed_sbh;

	set_nilfs_init(nilfs);
	err = 0;
 out:
	up_write(&nilfs->ns_sem);
	return err;

 failed_sbh:
723
	nilfs_release_super_block(nilfs);
724 725 726
	goto out;
}

727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750
int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
			    size_t nsegs)
{
	sector_t seg_start, seg_end;
	sector_t start = 0, nblocks = 0;
	unsigned int sects_per_block;
	__u64 *sn;
	int ret = 0;

	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
		bdev_logical_block_size(nilfs->ns_bdev);
	for (sn = segnump; sn < segnump + nsegs; sn++) {
		nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);

		if (!nblocks) {
			start = seg_start;
			nblocks = seg_end - seg_start + 1;
		} else if (start + nblocks == seg_start) {
			nblocks += seg_end - seg_start + 1;
		} else {
			ret = blkdev_issue_discard(nilfs->ns_bdev,
						   start * sects_per_block,
						   nblocks * sects_per_block,
						   GFP_NOFS,
751
						   BLKDEV_IFL_BARRIER);
752 753 754 755 756 757 758 759 760
			if (ret < 0)
				return ret;
			nblocks = 0;
		}
	}
	if (nblocks)
		ret = blkdev_issue_discard(nilfs->ns_bdev,
					   start * sects_per_block,
					   nblocks * sects_per_block,
761
					   GFP_NOFS, BLKDEV_IFL_BARRIER);
762 763 764
	return ret;
}

765 766 767 768 769 770
int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
{
	struct inode *dat = nilfs_dat_inode(nilfs);
	unsigned long ncleansegs;

	down_read(&NILFS_MDT(dat)->mi_sem);	/* XXX */
771
	ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
772
	up_read(&NILFS_MDT(dat)->mi_sem);	/* XXX */
773 774
	*nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
	return 0;
775 776 777 778 779
}

int nilfs_near_disk_full(struct the_nilfs *nilfs)
{
	unsigned long ncleansegs, nincsegs;
780 781 782 783 784 785

	ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
	nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
		nilfs->ns_blocks_per_segment + 1;

	return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
786 787
}

788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804
/**
 * nilfs_find_sbinfo - find existing nilfs_sb_info structure
 * @nilfs: nilfs object
 * @rw_mount: mount type (non-zero value for read/write mount)
 * @cno: checkpoint number (zero for read-only mount)
 *
 * nilfs_find_sbinfo() returns the nilfs_sb_info structure which
 * @rw_mount and @cno (in case of snapshots) matched.  If no instance
 * was found, NULL is returned.  Although the super block instance can
 * be unmounted after this function returns, the nilfs_sb_info struct
 * is kept on memory until nilfs_put_sbinfo() is called.
 */
struct nilfs_sb_info *nilfs_find_sbinfo(struct the_nilfs *nilfs,
					int rw_mount, __u64 cno)
{
	struct nilfs_sb_info *sbi;

805
	down_read(&nilfs->ns_super_sem);
806 807
	/*
	 * The SNAPSHOT flag and sb->s_flags are supposed to be
808
	 * protected with nilfs->ns_super_sem.
809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828
	 */
	sbi = nilfs->ns_current;
	if (rw_mount) {
		if (sbi && !(sbi->s_super->s_flags & MS_RDONLY))
			goto found; /* read/write mount */
		else
			goto out;
	} else if (cno == 0) {
		if (sbi && (sbi->s_super->s_flags & MS_RDONLY))
			goto found; /* read-only mount */
		else
			goto out;
	}

	list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
		if (nilfs_test_opt(sbi, SNAPSHOT) &&
		    sbi->s_snapshot_cno == cno)
			goto found; /* snapshot mount */
	}
 out:
829
	up_read(&nilfs->ns_super_sem);
830 831 832 833
	return NULL;

 found:
	atomic_inc(&sbi->s_count);
834
	up_read(&nilfs->ns_super_sem);
835 836 837
	return sbi;
}

838 839 840 841 842 843
int nilfs_checkpoint_is_mounted(struct the_nilfs *nilfs, __u64 cno,
				int snapshot_mount)
{
	struct nilfs_sb_info *sbi;
	int ret = 0;

844
	down_read(&nilfs->ns_super_sem);
845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860
	if (cno == 0 || cno > nilfs->ns_cno)
		goto out_unlock;

	list_for_each_entry(sbi, &nilfs->ns_supers, s_list) {
		if (sbi->s_snapshot_cno == cno &&
		    (!snapshot_mount || nilfs_test_opt(sbi, SNAPSHOT))) {
					/* exclude read-only mounts */
			ret++;
			break;
		}
	}
	/* for protecting recent checkpoints */
	if (cno >= nilfs_last_cno(nilfs))
		ret++;

 out_unlock:
861
	up_read(&nilfs->ns_super_sem);
862 863
	return ret;
}
反馈
建议
客服 返回
顶部