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v6.2
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * NILFS segment usage file.
   4 *
   5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Written by Koji Sato.
   8 * Revised by Ryusuke Konishi.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
   9 */
  10
  11#include <linux/kernel.h>
  12#include <linux/fs.h>
  13#include <linux/string.h>
  14#include <linux/buffer_head.h>
  15#include <linux/errno.h>
 
  16#include "mdt.h"
  17#include "sufile.h"
  18
  19#include <trace/events/nilfs2.h>
  20
  21/**
  22 * struct nilfs_sufile_info - on-memory private data of sufile
  23 * @mi: on-memory private data of metadata file
  24 * @ncleansegs: number of clean segments
  25 * @allocmin: lower limit of allocatable segment range
  26 * @allocmax: upper limit of allocatable segment range
  27 */
  28struct nilfs_sufile_info {
  29	struct nilfs_mdt_info mi;
  30	unsigned long ncleansegs;/* number of clean segments */
  31	__u64 allocmin;		/* lower limit of allocatable segment range */
  32	__u64 allocmax;		/* upper limit of allocatable segment range */
  33};
  34
  35static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
  36{
  37	return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
  38}
  39
  40static inline unsigned long
  41nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
  42{
  43	return NILFS_MDT(sufile)->mi_entries_per_block;
  44}
  45
  46static unsigned long
  47nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
  48{
  49	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  50
  51	do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  52	return (unsigned long)t;
  53}
  54
  55static unsigned long
  56nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
  57{
  58	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  59
  60	return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  61}
  62
  63static unsigned long
  64nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
  65				     __u64 max)
  66{
  67	return min_t(unsigned long,
  68		     nilfs_sufile_segment_usages_per_block(sufile) -
  69		     nilfs_sufile_get_offset(sufile, curr),
  70		     max - curr + 1);
  71}
  72
  73static struct nilfs_segment_usage *
  74nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
  75				     struct buffer_head *bh, void *kaddr)
  76{
  77	return kaddr + bh_offset(bh) +
  78		nilfs_sufile_get_offset(sufile, segnum) *
  79		NILFS_MDT(sufile)->mi_entry_size;
  80}
  81
  82static inline int nilfs_sufile_get_header_block(struct inode *sufile,
  83						struct buffer_head **bhp)
  84{
  85	return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  86}
  87
  88static inline int
  89nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
  90				     int create, struct buffer_head **bhp)
  91{
  92	return nilfs_mdt_get_block(sufile,
  93				   nilfs_sufile_get_blkoff(sufile, segnum),
  94				   create, NULL, bhp);
  95}
  96
  97static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
  98						   __u64 segnum)
  99{
 100	return nilfs_mdt_delete_block(sufile,
 101				      nilfs_sufile_get_blkoff(sufile, segnum));
 102}
 103
 104static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
 105				     u64 ncleanadd, u64 ndirtyadd)
 106{
 107	struct nilfs_sufile_header *header;
 108	void *kaddr;
 109
 110	kaddr = kmap_atomic(header_bh->b_page);
 111	header = kaddr + bh_offset(header_bh);
 112	le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
 113	le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
 114	kunmap_atomic(kaddr);
 115
 116	mark_buffer_dirty(header_bh);
 117}
 118
 119/**
 120 * nilfs_sufile_get_ncleansegs - return the number of clean segments
 121 * @sufile: inode of segment usage file
 122 */
 123unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
 124{
 125	return NILFS_SUI(sufile)->ncleansegs;
 126}
 127
 128/**
 129 * nilfs_sufile_updatev - modify multiple segment usages at a time
 130 * @sufile: inode of segment usage file
 131 * @segnumv: array of segment numbers
 132 * @nsegs: size of @segnumv array
 133 * @create: creation flag
 134 * @ndone: place to store number of modified segments on @segnumv
 135 * @dofunc: primitive operation for the update
 136 *
 137 * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
 138 * against the given array of segments.  The @dofunc is called with
 139 * buffers of a header block and the sufile block in which the target
 140 * segment usage entry is contained.  If @ndone is given, the number
 141 * of successfully modified segments from the head is stored in the
 142 * place @ndone points to.
 143 *
 144 * Return Value: On success, zero is returned.  On error, one of the
 145 * following negative error codes is returned.
 146 *
 147 * %-EIO - I/O error.
 148 *
 149 * %-ENOMEM - Insufficient amount of memory available.
 150 *
 151 * %-ENOENT - Given segment usage is in hole block (may be returned if
 152 *            @create is zero)
 153 *
 154 * %-EINVAL - Invalid segment usage number
 155 */
 156int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
 157			 int create, size_t *ndone,
 158			 void (*dofunc)(struct inode *, __u64,
 159					struct buffer_head *,
 160					struct buffer_head *))
 161{
 162	struct buffer_head *header_bh, *bh;
 163	unsigned long blkoff, prev_blkoff;
 164	__u64 *seg;
 165	size_t nerr = 0, n = 0;
 166	int ret = 0;
 167
 168	if (unlikely(nsegs == 0))
 169		goto out;
 170
 171	down_write(&NILFS_MDT(sufile)->mi_sem);
 172	for (seg = segnumv; seg < segnumv + nsegs; seg++) {
 173		if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
 174			nilfs_warn(sufile->i_sb,
 175				   "%s: invalid segment number: %llu",
 176				   __func__, (unsigned long long)*seg);
 177			nerr++;
 178		}
 179	}
 180	if (nerr > 0) {
 181		ret = -EINVAL;
 182		goto out_sem;
 183	}
 184
 185	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 186	if (ret < 0)
 187		goto out_sem;
 188
 189	seg = segnumv;
 190	blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 191	ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 192	if (ret < 0)
 193		goto out_header;
 194
 195	for (;;) {
 196		dofunc(sufile, *seg, header_bh, bh);
 197
 198		if (++seg >= segnumv + nsegs)
 199			break;
 200		prev_blkoff = blkoff;
 201		blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 202		if (blkoff == prev_blkoff)
 203			continue;
 204
 205		/* get different block */
 206		brelse(bh);
 207		ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 208		if (unlikely(ret < 0))
 209			goto out_header;
 210	}
 211	brelse(bh);
 212
 213 out_header:
 214	n = seg - segnumv;
 215	brelse(header_bh);
 216 out_sem:
 217	up_write(&NILFS_MDT(sufile)->mi_sem);
 218 out:
 219	if (ndone)
 220		*ndone = n;
 221	return ret;
 222}
 223
 224int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
 225			void (*dofunc)(struct inode *, __u64,
 226				       struct buffer_head *,
 227				       struct buffer_head *))
 228{
 229	struct buffer_head *header_bh, *bh;
 230	int ret;
 231
 232	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
 233		nilfs_warn(sufile->i_sb, "%s: invalid segment number: %llu",
 234			   __func__, (unsigned long long)segnum);
 235		return -EINVAL;
 236	}
 237	down_write(&NILFS_MDT(sufile)->mi_sem);
 238
 239	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 240	if (ret < 0)
 241		goto out_sem;
 242
 243	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 244	if (!ret) {
 245		dofunc(sufile, segnum, header_bh, bh);
 246		brelse(bh);
 247	}
 248	brelse(header_bh);
 249
 250 out_sem:
 251	up_write(&NILFS_MDT(sufile)->mi_sem);
 252	return ret;
 253}
 254
 255/**
 256 * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 257 * @sufile: inode of segment usage file
 258 * @start: minimum segment number of allocatable region (inclusive)
 259 * @end: maximum segment number of allocatable region (inclusive)
 260 *
 261 * Return Value: On success, 0 is returned.  On error, one of the
 262 * following negative error codes is returned.
 263 *
 264 * %-ERANGE - invalid segment region
 265 */
 266int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 267{
 268	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 269	__u64 nsegs;
 270	int ret = -ERANGE;
 271
 272	down_write(&NILFS_MDT(sufile)->mi_sem);
 273	nsegs = nilfs_sufile_get_nsegments(sufile);
 274
 275	if (start <= end && end < nsegs) {
 276		sui->allocmin = start;
 277		sui->allocmax = end;
 278		ret = 0;
 279	}
 280	up_write(&NILFS_MDT(sufile)->mi_sem);
 281	return ret;
 282}
 283
 284/**
 285 * nilfs_sufile_alloc - allocate a segment
 286 * @sufile: inode of segment usage file
 287 * @segnump: pointer to segment number
 288 *
 289 * Description: nilfs_sufile_alloc() allocates a clean segment.
 290 *
 291 * Return Value: On success, 0 is returned and the segment number of the
 292 * allocated segment is stored in the place pointed by @segnump. On error, one
 293 * of the following negative error codes is returned.
 294 *
 295 * %-EIO - I/O error.
 296 *
 297 * %-ENOMEM - Insufficient amount of memory available.
 298 *
 299 * %-ENOSPC - No clean segment left.
 300 */
 301int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 302{
 303	struct buffer_head *header_bh, *su_bh;
 304	struct nilfs_sufile_header *header;
 305	struct nilfs_segment_usage *su;
 306	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 307	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 308	__u64 segnum, maxsegnum, last_alloc;
 309	void *kaddr;
 310	unsigned long nsegments, nsus, cnt;
 311	int ret, j;
 312
 313	down_write(&NILFS_MDT(sufile)->mi_sem);
 314
 315	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 316	if (ret < 0)
 317		goto out_sem;
 318	kaddr = kmap_atomic(header_bh->b_page);
 319	header = kaddr + bh_offset(header_bh);
 320	last_alloc = le64_to_cpu(header->sh_last_alloc);
 321	kunmap_atomic(kaddr);
 322
 323	nsegments = nilfs_sufile_get_nsegments(sufile);
 324	maxsegnum = sui->allocmax;
 325	segnum = last_alloc + 1;
 326	if (segnum < sui->allocmin || segnum > sui->allocmax)
 327		segnum = sui->allocmin;
 328
 329	for (cnt = 0; cnt < nsegments; cnt += nsus) {
 330		if (segnum > maxsegnum) {
 331			if (cnt < sui->allocmax - sui->allocmin + 1) {
 332				/*
 333				 * wrap around in the limited region.
 334				 * if allocation started from
 335				 * sui->allocmin, this never happens.
 336				 */
 337				segnum = sui->allocmin;
 338				maxsegnum = last_alloc;
 339			} else if (segnum > sui->allocmin &&
 340				   sui->allocmax + 1 < nsegments) {
 341				segnum = sui->allocmax + 1;
 342				maxsegnum = nsegments - 1;
 343			} else if (sui->allocmin > 0)  {
 344				segnum = 0;
 345				maxsegnum = sui->allocmin - 1;
 346			} else {
 347				break; /* never happens */
 348			}
 349		}
 350		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 351		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 352							   &su_bh);
 353		if (ret < 0)
 354			goto out_header;
 355		kaddr = kmap_atomic(su_bh->b_page);
 356		su = nilfs_sufile_block_get_segment_usage(
 357			sufile, segnum, su_bh, kaddr);
 358
 359		nsus = nilfs_sufile_segment_usages_in_block(
 360			sufile, segnum, maxsegnum);
 361		for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 362			if (!nilfs_segment_usage_clean(su))
 363				continue;
 364			/* found a clean segment */
 365			nilfs_segment_usage_set_dirty(su);
 366			kunmap_atomic(kaddr);
 367
 368			kaddr = kmap_atomic(header_bh->b_page);
 369			header = kaddr + bh_offset(header_bh);
 370			le64_add_cpu(&header->sh_ncleansegs, -1);
 371			le64_add_cpu(&header->sh_ndirtysegs, 1);
 372			header->sh_last_alloc = cpu_to_le64(segnum);
 373			kunmap_atomic(kaddr);
 374
 375			sui->ncleansegs--;
 376			mark_buffer_dirty(header_bh);
 377			mark_buffer_dirty(su_bh);
 378			nilfs_mdt_mark_dirty(sufile);
 379			brelse(su_bh);
 380			*segnump = segnum;
 381
 382			trace_nilfs2_segment_usage_allocated(sufile, segnum);
 383
 384			goto out_header;
 385		}
 386
 387		kunmap_atomic(kaddr);
 388		brelse(su_bh);
 389	}
 390
 391	/* no segments left */
 392	ret = -ENOSPC;
 393
 394 out_header:
 395	brelse(header_bh);
 396
 397 out_sem:
 398	up_write(&NILFS_MDT(sufile)->mi_sem);
 399	return ret;
 400}
 401
 402void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 403				 struct buffer_head *header_bh,
 404				 struct buffer_head *su_bh)
 405{
 406	struct nilfs_segment_usage *su;
 407	void *kaddr;
 408
 409	kaddr = kmap_atomic(su_bh->b_page);
 410	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 411	if (unlikely(!nilfs_segment_usage_clean(su))) {
 412		nilfs_warn(sufile->i_sb, "%s: segment %llu must be clean",
 413			   __func__, (unsigned long long)segnum);
 414		kunmap_atomic(kaddr);
 415		return;
 416	}
 417	nilfs_segment_usage_set_dirty(su);
 418	kunmap_atomic(kaddr);
 419
 420	nilfs_sufile_mod_counter(header_bh, -1, 1);
 421	NILFS_SUI(sufile)->ncleansegs--;
 422
 423	mark_buffer_dirty(su_bh);
 424	nilfs_mdt_mark_dirty(sufile);
 425}
 426
 427void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 428			   struct buffer_head *header_bh,
 429			   struct buffer_head *su_bh)
 430{
 431	struct nilfs_segment_usage *su;
 432	void *kaddr;
 433	int clean, dirty;
 434
 435	kaddr = kmap_atomic(su_bh->b_page);
 436	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 437	if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
 438	    su->su_nblocks == cpu_to_le32(0)) {
 439		kunmap_atomic(kaddr);
 440		return;
 441	}
 442	clean = nilfs_segment_usage_clean(su);
 443	dirty = nilfs_segment_usage_dirty(su);
 444
 445	/* make the segment garbage */
 446	su->su_lastmod = cpu_to_le64(0);
 447	su->su_nblocks = cpu_to_le32(0);
 448	su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
 449	kunmap_atomic(kaddr);
 450
 451	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 452	NILFS_SUI(sufile)->ncleansegs -= clean;
 453
 454	mark_buffer_dirty(su_bh);
 455	nilfs_mdt_mark_dirty(sufile);
 456}
 457
 458void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 459			  struct buffer_head *header_bh,
 460			  struct buffer_head *su_bh)
 461{
 462	struct nilfs_segment_usage *su;
 463	void *kaddr;
 464	int sudirty;
 465
 466	kaddr = kmap_atomic(su_bh->b_page);
 467	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 468	if (nilfs_segment_usage_clean(su)) {
 469		nilfs_warn(sufile->i_sb, "%s: segment %llu is already clean",
 470			   __func__, (unsigned long long)segnum);
 471		kunmap_atomic(kaddr);
 472		return;
 473	}
 474	WARN_ON(nilfs_segment_usage_error(su));
 475	WARN_ON(!nilfs_segment_usage_dirty(su));
 476
 477	sudirty = nilfs_segment_usage_dirty(su);
 478	nilfs_segment_usage_set_clean(su);
 479	kunmap_atomic(kaddr);
 480	mark_buffer_dirty(su_bh);
 481
 482	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 483	NILFS_SUI(sufile)->ncleansegs++;
 484
 485	nilfs_mdt_mark_dirty(sufile);
 486
 487	trace_nilfs2_segment_usage_freed(sufile, segnum);
 488}
 489
 490/**
 491 * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 492 * @sufile: inode of segment usage file
 493 * @segnum: segment number
 494 */
 495int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 496{
 497	struct buffer_head *bh;
 498	void *kaddr;
 499	struct nilfs_segment_usage *su;
 500	int ret;
 501
 502	down_write(&NILFS_MDT(sufile)->mi_sem);
 503	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 504	if (!ret) {
 505		mark_buffer_dirty(bh);
 506		nilfs_mdt_mark_dirty(sufile);
 507		kaddr = kmap_atomic(bh->b_page);
 508		su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 509		nilfs_segment_usage_set_dirty(su);
 510		kunmap_atomic(kaddr);
 511		brelse(bh);
 512	}
 513	up_write(&NILFS_MDT(sufile)->mi_sem);
 514	return ret;
 515}
 516
 517/**
 518 * nilfs_sufile_set_segment_usage - set usage of a segment
 519 * @sufile: inode of segment usage file
 520 * @segnum: segment number
 521 * @nblocks: number of live blocks in the segment
 522 * @modtime: modification time (option)
 523 */
 524int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 525				   unsigned long nblocks, time64_t modtime)
 526{
 527	struct buffer_head *bh;
 528	struct nilfs_segment_usage *su;
 529	void *kaddr;
 530	int ret;
 531
 532	down_write(&NILFS_MDT(sufile)->mi_sem);
 533	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 534	if (ret < 0)
 535		goto out_sem;
 536
 537	kaddr = kmap_atomic(bh->b_page);
 538	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 539	WARN_ON(nilfs_segment_usage_error(su));
 540	if (modtime)
 541		su->su_lastmod = cpu_to_le64(modtime);
 542	su->su_nblocks = cpu_to_le32(nblocks);
 543	kunmap_atomic(kaddr);
 544
 545	mark_buffer_dirty(bh);
 546	nilfs_mdt_mark_dirty(sufile);
 547	brelse(bh);
 548
 549 out_sem:
 550	up_write(&NILFS_MDT(sufile)->mi_sem);
 551	return ret;
 552}
 553
 554/**
 555 * nilfs_sufile_get_stat - get segment usage statistics
 556 * @sufile: inode of segment usage file
 557 * @sustat: pointer to a structure of segment usage statistics
 558 *
 559 * Description: nilfs_sufile_get_stat() returns information about segment
 560 * usage.
 561 *
 562 * Return Value: On success, 0 is returned, and segment usage information is
 563 * stored in the place pointed by @sustat. On error, one of the following
 564 * negative error codes is returned.
 565 *
 566 * %-EIO - I/O error.
 567 *
 568 * %-ENOMEM - Insufficient amount of memory available.
 569 */
 570int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 571{
 572	struct buffer_head *header_bh;
 573	struct nilfs_sufile_header *header;
 574	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 575	void *kaddr;
 576	int ret;
 577
 578	down_read(&NILFS_MDT(sufile)->mi_sem);
 579
 580	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 581	if (ret < 0)
 582		goto out_sem;
 583
 584	kaddr = kmap_atomic(header_bh->b_page);
 585	header = kaddr + bh_offset(header_bh);
 586	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 587	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 588	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 589	sustat->ss_ctime = nilfs->ns_ctime;
 590	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 591	spin_lock(&nilfs->ns_last_segment_lock);
 592	sustat->ss_prot_seq = nilfs->ns_prot_seq;
 593	spin_unlock(&nilfs->ns_last_segment_lock);
 594	kunmap_atomic(kaddr);
 595	brelse(header_bh);
 596
 597 out_sem:
 598	up_read(&NILFS_MDT(sufile)->mi_sem);
 599	return ret;
 600}
 601
 602void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 603			       struct buffer_head *header_bh,
 604			       struct buffer_head *su_bh)
 605{
 606	struct nilfs_segment_usage *su;
 607	void *kaddr;
 608	int suclean;
 609
 610	kaddr = kmap_atomic(su_bh->b_page);
 611	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 612	if (nilfs_segment_usage_error(su)) {
 613		kunmap_atomic(kaddr);
 614		return;
 615	}
 616	suclean = nilfs_segment_usage_clean(su);
 617	nilfs_segment_usage_set_error(su);
 618	kunmap_atomic(kaddr);
 619
 620	if (suclean) {
 621		nilfs_sufile_mod_counter(header_bh, -1, 0);
 622		NILFS_SUI(sufile)->ncleansegs--;
 623	}
 624	mark_buffer_dirty(su_bh);
 625	nilfs_mdt_mark_dirty(sufile);
 626}
 627
 628/**
 629 * nilfs_sufile_truncate_range - truncate range of segment array
 630 * @sufile: inode of segment usage file
 631 * @start: start segment number (inclusive)
 632 * @end: end segment number (inclusive)
 633 *
 634 * Return Value: On success, 0 is returned.  On error, one of the
 635 * following negative error codes is returned.
 636 *
 637 * %-EIO - I/O error.
 638 *
 639 * %-ENOMEM - Insufficient amount of memory available.
 640 *
 641 * %-EINVAL - Invalid number of segments specified
 642 *
 643 * %-EBUSY - Dirty or active segments are present in the range
 644 */
 645static int nilfs_sufile_truncate_range(struct inode *sufile,
 646				       __u64 start, __u64 end)
 647{
 648	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 649	struct buffer_head *header_bh;
 650	struct buffer_head *su_bh;
 651	struct nilfs_segment_usage *su, *su2;
 652	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 653	unsigned long segusages_per_block;
 654	unsigned long nsegs, ncleaned;
 655	__u64 segnum;
 656	void *kaddr;
 657	ssize_t n, nc;
 658	int ret;
 659	int j;
 660
 661	nsegs = nilfs_sufile_get_nsegments(sufile);
 662
 663	ret = -EINVAL;
 664	if (start > end || start >= nsegs)
 665		goto out;
 666
 667	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 668	if (ret < 0)
 669		goto out;
 670
 671	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 672	ncleaned = 0;
 673
 674	for (segnum = start; segnum <= end; segnum += n) {
 675		n = min_t(unsigned long,
 676			  segusages_per_block -
 677				  nilfs_sufile_get_offset(sufile, segnum),
 678			  end - segnum + 1);
 679		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 680							   &su_bh);
 681		if (ret < 0) {
 682			if (ret != -ENOENT)
 683				goto out_header;
 684			/* hole */
 685			continue;
 686		}
 687		kaddr = kmap_atomic(su_bh->b_page);
 688		su = nilfs_sufile_block_get_segment_usage(
 689			sufile, segnum, su_bh, kaddr);
 690		su2 = su;
 691		for (j = 0; j < n; j++, su = (void *)su + susz) {
 692			if ((le32_to_cpu(su->su_flags) &
 693			     ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
 694			    nilfs_segment_is_active(nilfs, segnum + j)) {
 695				ret = -EBUSY;
 696				kunmap_atomic(kaddr);
 697				brelse(su_bh);
 698				goto out_header;
 699			}
 700		}
 701		nc = 0;
 702		for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 703			if (nilfs_segment_usage_error(su)) {
 704				nilfs_segment_usage_set_clean(su);
 705				nc++;
 706			}
 707		}
 708		kunmap_atomic(kaddr);
 709		if (nc > 0) {
 710			mark_buffer_dirty(su_bh);
 711			ncleaned += nc;
 712		}
 713		brelse(su_bh);
 714
 715		if (n == segusages_per_block) {
 716			/* make hole */
 717			nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 718		}
 719	}
 720	ret = 0;
 721
 722out_header:
 723	if (ncleaned > 0) {
 724		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 725		nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 726		nilfs_mdt_mark_dirty(sufile);
 727	}
 728	brelse(header_bh);
 729out:
 730	return ret;
 731}
 732
 733/**
 734 * nilfs_sufile_resize - resize segment array
 735 * @sufile: inode of segment usage file
 736 * @newnsegs: new number of segments
 737 *
 738 * Return Value: On success, 0 is returned.  On error, one of the
 739 * following negative error codes is returned.
 740 *
 741 * %-EIO - I/O error.
 742 *
 743 * %-ENOMEM - Insufficient amount of memory available.
 744 *
 745 * %-ENOSPC - Enough free space is not left for shrinking
 746 *
 747 * %-EBUSY - Dirty or active segments exist in the region to be truncated
 748 */
 749int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 750{
 751	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 752	struct buffer_head *header_bh;
 753	struct nilfs_sufile_header *header;
 754	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 755	void *kaddr;
 756	unsigned long nsegs, nrsvsegs;
 757	int ret = 0;
 758
 759	down_write(&NILFS_MDT(sufile)->mi_sem);
 760
 761	nsegs = nilfs_sufile_get_nsegments(sufile);
 762	if (nsegs == newnsegs)
 763		goto out;
 764
 765	ret = -ENOSPC;
 766	nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 767	if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 768		goto out;
 769
 770	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 771	if (ret < 0)
 772		goto out;
 773
 774	if (newnsegs > nsegs) {
 775		sui->ncleansegs += newnsegs - nsegs;
 776	} else /* newnsegs < nsegs */ {
 777		ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 778		if (ret < 0)
 779			goto out_header;
 780
 781		sui->ncleansegs -= nsegs - newnsegs;
 782	}
 783
 784	kaddr = kmap_atomic(header_bh->b_page);
 785	header = kaddr + bh_offset(header_bh);
 786	header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 787	kunmap_atomic(kaddr);
 788
 789	mark_buffer_dirty(header_bh);
 790	nilfs_mdt_mark_dirty(sufile);
 791	nilfs_set_nsegments(nilfs, newnsegs);
 792
 793out_header:
 794	brelse(header_bh);
 795out:
 796	up_write(&NILFS_MDT(sufile)->mi_sem);
 797	return ret;
 798}
 799
 800/**
 801 * nilfs_sufile_get_suinfo -
 802 * @sufile: inode of segment usage file
 803 * @segnum: segment number to start looking
 804 * @buf: array of suinfo
 805 * @sisz: byte size of suinfo
 806 * @nsi: size of suinfo array
 807 *
 808 * Description:
 809 *
 810 * Return Value: On success, 0 is returned and .... On error, one of the
 811 * following negative error codes is returned.
 812 *
 813 * %-EIO - I/O error.
 814 *
 815 * %-ENOMEM - Insufficient amount of memory available.
 816 */
 817ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 818				unsigned int sisz, size_t nsi)
 819{
 820	struct buffer_head *su_bh;
 821	struct nilfs_segment_usage *su;
 822	struct nilfs_suinfo *si = buf;
 823	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 824	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 825	void *kaddr;
 826	unsigned long nsegs, segusages_per_block;
 827	ssize_t n;
 828	int ret, i, j;
 829
 830	down_read(&NILFS_MDT(sufile)->mi_sem);
 831
 832	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 833	nsegs = min_t(unsigned long,
 834		      nilfs_sufile_get_nsegments(sufile) - segnum,
 835		      nsi);
 836	for (i = 0; i < nsegs; i += n, segnum += n) {
 837		n = min_t(unsigned long,
 838			  segusages_per_block -
 839				  nilfs_sufile_get_offset(sufile, segnum),
 840			  nsegs - i);
 841		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 842							   &su_bh);
 843		if (ret < 0) {
 844			if (ret != -ENOENT)
 845				goto out;
 846			/* hole */
 847			memset(si, 0, sisz * n);
 848			si = (void *)si + sisz * n;
 849			continue;
 850		}
 851
 852		kaddr = kmap_atomic(su_bh->b_page);
 853		su = nilfs_sufile_block_get_segment_usage(
 854			sufile, segnum, su_bh, kaddr);
 855		for (j = 0; j < n;
 856		     j++, su = (void *)su + susz, si = (void *)si + sisz) {
 857			si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 858			si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 859			si->sui_flags = le32_to_cpu(su->su_flags) &
 860				~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 861			if (nilfs_segment_is_active(nilfs, segnum + j))
 862				si->sui_flags |=
 863					BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 864		}
 865		kunmap_atomic(kaddr);
 866		brelse(su_bh);
 867	}
 868	ret = nsegs;
 869
 870 out:
 871	up_read(&NILFS_MDT(sufile)->mi_sem);
 872	return ret;
 873}
 874
 875/**
 876 * nilfs_sufile_set_suinfo - sets segment usage info
 877 * @sufile: inode of segment usage file
 878 * @buf: array of suinfo_update
 879 * @supsz: byte size of suinfo_update
 880 * @nsup: size of suinfo_update array
 881 *
 882 * Description: Takes an array of nilfs_suinfo_update structs and updates
 883 * segment usage accordingly. Only the fields indicated by the sup_flags
 884 * are updated.
 885 *
 886 * Return Value: On success, 0 is returned. On error, one of the
 887 * following negative error codes is returned.
 888 *
 889 * %-EIO - I/O error.
 890 *
 891 * %-ENOMEM - Insufficient amount of memory available.
 892 *
 893 * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 894 */
 895ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 896				unsigned int supsz, size_t nsup)
 897{
 898	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 899	struct buffer_head *header_bh, *bh;
 900	struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 901	struct nilfs_segment_usage *su;
 902	void *kaddr;
 903	unsigned long blkoff, prev_blkoff;
 904	int cleansi, cleansu, dirtysi, dirtysu;
 905	long ncleaned = 0, ndirtied = 0;
 906	int ret = 0;
 907
 908	if (unlikely(nsup == 0))
 909		return ret;
 910
 911	for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 912		if (sup->sup_segnum >= nilfs->ns_nsegments
 913			|| (sup->sup_flags &
 914				(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 915			|| (nilfs_suinfo_update_nblocks(sup) &&
 916				sup->sup_sui.sui_nblocks >
 917				nilfs->ns_blocks_per_segment))
 918			return -EINVAL;
 919	}
 920
 921	down_write(&NILFS_MDT(sufile)->mi_sem);
 922
 923	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 924	if (ret < 0)
 925		goto out_sem;
 926
 927	sup = buf;
 928	blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 929	ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 930	if (ret < 0)
 931		goto out_header;
 932
 933	for (;;) {
 934		kaddr = kmap_atomic(bh->b_page);
 935		su = nilfs_sufile_block_get_segment_usage(
 936			sufile, sup->sup_segnum, bh, kaddr);
 937
 938		if (nilfs_suinfo_update_lastmod(sup))
 939			su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 940
 941		if (nilfs_suinfo_update_nblocks(sup))
 942			su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 943
 944		if (nilfs_suinfo_update_flags(sup)) {
 945			/*
 946			 * Active flag is a virtual flag projected by running
 947			 * nilfs kernel code - drop it not to write it to
 948			 * disk.
 949			 */
 950			sup->sup_sui.sui_flags &=
 951					~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 952
 953			cleansi = nilfs_suinfo_clean(&sup->sup_sui);
 954			cleansu = nilfs_segment_usage_clean(su);
 955			dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
 956			dirtysu = nilfs_segment_usage_dirty(su);
 957
 958			if (cleansi && !cleansu)
 959				++ncleaned;
 960			else if (!cleansi && cleansu)
 961				--ncleaned;
 962
 963			if (dirtysi && !dirtysu)
 964				++ndirtied;
 965			else if (!dirtysi && dirtysu)
 966				--ndirtied;
 967
 968			su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
 969		}
 970
 971		kunmap_atomic(kaddr);
 972
 973		sup = (void *)sup + supsz;
 974		if (sup >= supend)
 975			break;
 976
 977		prev_blkoff = blkoff;
 978		blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 979		if (blkoff == prev_blkoff)
 980			continue;
 981
 982		/* get different block */
 983		mark_buffer_dirty(bh);
 984		put_bh(bh);
 985		ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 986		if (unlikely(ret < 0))
 987			goto out_mark;
 988	}
 989	mark_buffer_dirty(bh);
 990	put_bh(bh);
 991
 992 out_mark:
 993	if (ncleaned || ndirtied) {
 994		nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
 995				(u64)ndirtied);
 996		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 997	}
 998	nilfs_mdt_mark_dirty(sufile);
 999 out_header:
1000	put_bh(header_bh);
1001 out_sem:
1002	up_write(&NILFS_MDT(sufile)->mi_sem);
1003	return ret;
1004}
1005
1006/**
1007 * nilfs_sufile_trim_fs() - trim ioctl handle function
1008 * @sufile: inode of segment usage file
1009 * @range: fstrim_range structure
1010 *
1011 * start:	First Byte to trim
1012 * len:		number of Bytes to trim from start
1013 * minlen:	minimum extent length in Bytes
1014 *
1015 * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1016 * from start to start+len. start is rounded up to the next block boundary
1017 * and start+len is rounded down. For each clean segment blkdev_issue_discard
1018 * function is invoked.
1019 *
1020 * Return Value: On success, 0 is returned or negative error code, otherwise.
1021 */
1022int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1023{
1024	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1025	struct buffer_head *su_bh;
1026	struct nilfs_segment_usage *su;
1027	void *kaddr;
1028	size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1029	sector_t seg_start, seg_end, start_block, end_block;
1030	sector_t start = 0, nblocks = 0;
1031	u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1032	int ret = 0;
1033	unsigned int sects_per_block;
1034
1035	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1036			bdev_logical_block_size(nilfs->ns_bdev);
1037	len = range->len >> nilfs->ns_blocksize_bits;
1038	minlen = range->minlen >> nilfs->ns_blocksize_bits;
1039	max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1040
1041	if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1042		return -EINVAL;
1043
1044	start_block = (range->start + nilfs->ns_blocksize - 1) >>
1045			nilfs->ns_blocksize_bits;
1046
1047	/*
1048	 * range->len can be very large (actually, it is set to
1049	 * ULLONG_MAX by default) - truncate upper end of the range
1050	 * carefully so as not to overflow.
1051	 */
1052	if (max_blocks - start_block < len)
1053		end_block = max_blocks - 1;
1054	else
1055		end_block = start_block + len - 1;
1056
1057	segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1058	segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1059
1060	down_read(&NILFS_MDT(sufile)->mi_sem);
1061
1062	while (segnum <= segnum_end) {
1063		n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1064				segnum_end);
1065
1066		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1067							   &su_bh);
1068		if (ret < 0) {
1069			if (ret != -ENOENT)
1070				goto out_sem;
1071			/* hole */
1072			segnum += n;
1073			continue;
1074		}
1075
1076		kaddr = kmap_atomic(su_bh->b_page);
1077		su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1078				su_bh, kaddr);
1079		for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1080			if (!nilfs_segment_usage_clean(su))
1081				continue;
1082
1083			nilfs_get_segment_range(nilfs, segnum, &seg_start,
1084						&seg_end);
1085
1086			if (!nblocks) {
1087				/* start new extent */
1088				start = seg_start;
1089				nblocks = seg_end - seg_start + 1;
1090				continue;
1091			}
1092
1093			if (start + nblocks == seg_start) {
1094				/* add to previous extent */
1095				nblocks += seg_end - seg_start + 1;
1096				continue;
1097			}
1098
1099			/* discard previous extent */
1100			if (start < start_block) {
1101				nblocks -= start_block - start;
1102				start = start_block;
1103			}
1104
1105			if (nblocks >= minlen) {
1106				kunmap_atomic(kaddr);
1107
1108				ret = blkdev_issue_discard(nilfs->ns_bdev,
1109						start * sects_per_block,
1110						nblocks * sects_per_block,
1111						GFP_NOFS);
1112				if (ret < 0) {
1113					put_bh(su_bh);
1114					goto out_sem;
1115				}
1116
1117				ndiscarded += nblocks;
1118				kaddr = kmap_atomic(su_bh->b_page);
1119				su = nilfs_sufile_block_get_segment_usage(
1120					sufile, segnum, su_bh, kaddr);
1121			}
1122
1123			/* start new extent */
1124			start = seg_start;
1125			nblocks = seg_end - seg_start + 1;
1126		}
1127		kunmap_atomic(kaddr);
1128		put_bh(su_bh);
1129	}
1130
1131
1132	if (nblocks) {
1133		/* discard last extent */
1134		if (start < start_block) {
1135			nblocks -= start_block - start;
1136			start = start_block;
1137		}
1138		if (start + nblocks > end_block + 1)
1139			nblocks = end_block - start + 1;
1140
1141		if (nblocks >= minlen) {
1142			ret = blkdev_issue_discard(nilfs->ns_bdev,
1143					start * sects_per_block,
1144					nblocks * sects_per_block,
1145					GFP_NOFS);
1146			if (!ret)
1147				ndiscarded += nblocks;
1148		}
1149	}
1150
1151out_sem:
1152	up_read(&NILFS_MDT(sufile)->mi_sem);
1153
1154	range->len = ndiscarded << nilfs->ns_blocksize_bits;
1155	return ret;
1156}
1157
1158/**
1159 * nilfs_sufile_read - read or get sufile inode
1160 * @sb: super block instance
1161 * @susize: size of a segment usage entry
1162 * @raw_inode: on-disk sufile inode
1163 * @inodep: buffer to store the inode
1164 */
1165int nilfs_sufile_read(struct super_block *sb, size_t susize,
1166		      struct nilfs_inode *raw_inode, struct inode **inodep)
1167{
1168	struct inode *sufile;
1169	struct nilfs_sufile_info *sui;
1170	struct buffer_head *header_bh;
1171	struct nilfs_sufile_header *header;
1172	void *kaddr;
1173	int err;
1174
1175	if (susize > sb->s_blocksize) {
1176		nilfs_err(sb, "too large segment usage size: %zu bytes",
1177			  susize);
 
1178		return -EINVAL;
1179	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1180		nilfs_err(sb, "too small segment usage size: %zu bytes",
1181			  susize);
 
1182		return -EINVAL;
1183	}
1184
1185	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1186	if (unlikely(!sufile))
1187		return -ENOMEM;
1188	if (!(sufile->i_state & I_NEW))
1189		goto out;
1190
1191	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1192	if (err)
1193		goto failed;
1194
1195	nilfs_mdt_set_entry_size(sufile, susize,
1196				 sizeof(struct nilfs_sufile_header));
1197
1198	err = nilfs_read_inode_common(sufile, raw_inode);
1199	if (err)
1200		goto failed;
1201
1202	err = nilfs_sufile_get_header_block(sufile, &header_bh);
1203	if (err)
1204		goto failed;
1205
1206	sui = NILFS_SUI(sufile);
1207	kaddr = kmap_atomic(header_bh->b_page);
1208	header = kaddr + bh_offset(header_bh);
1209	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1210	kunmap_atomic(kaddr);
1211	brelse(header_bh);
1212
1213	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1214	sui->allocmin = 0;
1215
1216	unlock_new_inode(sufile);
1217 out:
1218	*inodep = sufile;
1219	return 0;
1220 failed:
1221	iget_failed(sufile);
1222	return err;
1223}
v4.6
 
   1/*
   2 * sufile.c - NILFS segment usage file.
   3 *
   4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Koji Sato <koji@osrg.net>.
  21 * Revised by Ryusuke Konishi <ryusuke@osrg.net>.
  22 */
  23
  24#include <linux/kernel.h>
  25#include <linux/fs.h>
  26#include <linux/string.h>
  27#include <linux/buffer_head.h>
  28#include <linux/errno.h>
  29#include <linux/nilfs2_fs.h>
  30#include "mdt.h"
  31#include "sufile.h"
  32
  33#include <trace/events/nilfs2.h>
  34
  35/**
  36 * struct nilfs_sufile_info - on-memory private data of sufile
  37 * @mi: on-memory private data of metadata file
  38 * @ncleansegs: number of clean segments
  39 * @allocmin: lower limit of allocatable segment range
  40 * @allocmax: upper limit of allocatable segment range
  41 */
  42struct nilfs_sufile_info {
  43	struct nilfs_mdt_info mi;
  44	unsigned long ncleansegs;/* number of clean segments */
  45	__u64 allocmin;		/* lower limit of allocatable segment range */
  46	__u64 allocmax;		/* upper limit of allocatable segment range */
  47};
  48
  49static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
  50{
  51	return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
  52}
  53
  54static inline unsigned long
  55nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
  56{
  57	return NILFS_MDT(sufile)->mi_entries_per_block;
  58}
  59
  60static unsigned long
  61nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
  62{
  63	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
 
  64	do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  65	return (unsigned long)t;
  66}
  67
  68static unsigned long
  69nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
  70{
  71	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
 
  72	return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  73}
  74
  75static unsigned long
  76nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
  77				     __u64 max)
  78{
  79	return min_t(unsigned long,
  80		     nilfs_sufile_segment_usages_per_block(sufile) -
  81		     nilfs_sufile_get_offset(sufile, curr),
  82		     max - curr + 1);
  83}
  84
  85static struct nilfs_segment_usage *
  86nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
  87				     struct buffer_head *bh, void *kaddr)
  88{
  89	return kaddr + bh_offset(bh) +
  90		nilfs_sufile_get_offset(sufile, segnum) *
  91		NILFS_MDT(sufile)->mi_entry_size;
  92}
  93
  94static inline int nilfs_sufile_get_header_block(struct inode *sufile,
  95						struct buffer_head **bhp)
  96{
  97	return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  98}
  99
 100static inline int
 101nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
 102				     int create, struct buffer_head **bhp)
 103{
 104	return nilfs_mdt_get_block(sufile,
 105				   nilfs_sufile_get_blkoff(sufile, segnum),
 106				   create, NULL, bhp);
 107}
 108
 109static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
 110						   __u64 segnum)
 111{
 112	return nilfs_mdt_delete_block(sufile,
 113				      nilfs_sufile_get_blkoff(sufile, segnum));
 114}
 115
 116static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
 117				     u64 ncleanadd, u64 ndirtyadd)
 118{
 119	struct nilfs_sufile_header *header;
 120	void *kaddr;
 121
 122	kaddr = kmap_atomic(header_bh->b_page);
 123	header = kaddr + bh_offset(header_bh);
 124	le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
 125	le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
 126	kunmap_atomic(kaddr);
 127
 128	mark_buffer_dirty(header_bh);
 129}
 130
 131/**
 132 * nilfs_sufile_get_ncleansegs - return the number of clean segments
 133 * @sufile: inode of segment usage file
 134 */
 135unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
 136{
 137	return NILFS_SUI(sufile)->ncleansegs;
 138}
 139
 140/**
 141 * nilfs_sufile_updatev - modify multiple segment usages at a time
 142 * @sufile: inode of segment usage file
 143 * @segnumv: array of segment numbers
 144 * @nsegs: size of @segnumv array
 145 * @create: creation flag
 146 * @ndone: place to store number of modified segments on @segnumv
 147 * @dofunc: primitive operation for the update
 148 *
 149 * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
 150 * against the given array of segments.  The @dofunc is called with
 151 * buffers of a header block and the sufile block in which the target
 152 * segment usage entry is contained.  If @ndone is given, the number
 153 * of successfully modified segments from the head is stored in the
 154 * place @ndone points to.
 155 *
 156 * Return Value: On success, zero is returned.  On error, one of the
 157 * following negative error codes is returned.
 158 *
 159 * %-EIO - I/O error.
 160 *
 161 * %-ENOMEM - Insufficient amount of memory available.
 162 *
 163 * %-ENOENT - Given segment usage is in hole block (may be returned if
 164 *            @create is zero)
 165 *
 166 * %-EINVAL - Invalid segment usage number
 167 */
 168int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
 169			 int create, size_t *ndone,
 170			 void (*dofunc)(struct inode *, __u64,
 171					struct buffer_head *,
 172					struct buffer_head *))
 173{
 174	struct buffer_head *header_bh, *bh;
 175	unsigned long blkoff, prev_blkoff;
 176	__u64 *seg;
 177	size_t nerr = 0, n = 0;
 178	int ret = 0;
 179
 180	if (unlikely(nsegs == 0))
 181		goto out;
 182
 183	down_write(&NILFS_MDT(sufile)->mi_sem);
 184	for (seg = segnumv; seg < segnumv + nsegs; seg++) {
 185		if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
 186			printk(KERN_WARNING
 187			       "%s: invalid segment number: %llu\n", __func__,
 188			       (unsigned long long)*seg);
 189			nerr++;
 190		}
 191	}
 192	if (nerr > 0) {
 193		ret = -EINVAL;
 194		goto out_sem;
 195	}
 196
 197	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 198	if (ret < 0)
 199		goto out_sem;
 200
 201	seg = segnumv;
 202	blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 203	ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 204	if (ret < 0)
 205		goto out_header;
 206
 207	for (;;) {
 208		dofunc(sufile, *seg, header_bh, bh);
 209
 210		if (++seg >= segnumv + nsegs)
 211			break;
 212		prev_blkoff = blkoff;
 213		blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 214		if (blkoff == prev_blkoff)
 215			continue;
 216
 217		/* get different block */
 218		brelse(bh);
 219		ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 220		if (unlikely(ret < 0))
 221			goto out_header;
 222	}
 223	brelse(bh);
 224
 225 out_header:
 226	n = seg - segnumv;
 227	brelse(header_bh);
 228 out_sem:
 229	up_write(&NILFS_MDT(sufile)->mi_sem);
 230 out:
 231	if (ndone)
 232		*ndone = n;
 233	return ret;
 234}
 235
 236int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
 237			void (*dofunc)(struct inode *, __u64,
 238				       struct buffer_head *,
 239				       struct buffer_head *))
 240{
 241	struct buffer_head *header_bh, *bh;
 242	int ret;
 243
 244	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
 245		printk(KERN_WARNING "%s: invalid segment number: %llu\n",
 246		       __func__, (unsigned long long)segnum);
 247		return -EINVAL;
 248	}
 249	down_write(&NILFS_MDT(sufile)->mi_sem);
 250
 251	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 252	if (ret < 0)
 253		goto out_sem;
 254
 255	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 256	if (!ret) {
 257		dofunc(sufile, segnum, header_bh, bh);
 258		brelse(bh);
 259	}
 260	brelse(header_bh);
 261
 262 out_sem:
 263	up_write(&NILFS_MDT(sufile)->mi_sem);
 264	return ret;
 265}
 266
 267/**
 268 * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 269 * @sufile: inode of segment usage file
 270 * @start: minimum segment number of allocatable region (inclusive)
 271 * @end: maximum segment number of allocatable region (inclusive)
 272 *
 273 * Return Value: On success, 0 is returned.  On error, one of the
 274 * following negative error codes is returned.
 275 *
 276 * %-ERANGE - invalid segment region
 277 */
 278int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 279{
 280	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 281	__u64 nsegs;
 282	int ret = -ERANGE;
 283
 284	down_write(&NILFS_MDT(sufile)->mi_sem);
 285	nsegs = nilfs_sufile_get_nsegments(sufile);
 286
 287	if (start <= end && end < nsegs) {
 288		sui->allocmin = start;
 289		sui->allocmax = end;
 290		ret = 0;
 291	}
 292	up_write(&NILFS_MDT(sufile)->mi_sem);
 293	return ret;
 294}
 295
 296/**
 297 * nilfs_sufile_alloc - allocate a segment
 298 * @sufile: inode of segment usage file
 299 * @segnump: pointer to segment number
 300 *
 301 * Description: nilfs_sufile_alloc() allocates a clean segment.
 302 *
 303 * Return Value: On success, 0 is returned and the segment number of the
 304 * allocated segment is stored in the place pointed by @segnump. On error, one
 305 * of the following negative error codes is returned.
 306 *
 307 * %-EIO - I/O error.
 308 *
 309 * %-ENOMEM - Insufficient amount of memory available.
 310 *
 311 * %-ENOSPC - No clean segment left.
 312 */
 313int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 314{
 315	struct buffer_head *header_bh, *su_bh;
 316	struct nilfs_sufile_header *header;
 317	struct nilfs_segment_usage *su;
 318	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 319	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 320	__u64 segnum, maxsegnum, last_alloc;
 321	void *kaddr;
 322	unsigned long nsegments, nsus, cnt;
 323	int ret, j;
 324
 325	down_write(&NILFS_MDT(sufile)->mi_sem);
 326
 327	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 328	if (ret < 0)
 329		goto out_sem;
 330	kaddr = kmap_atomic(header_bh->b_page);
 331	header = kaddr + bh_offset(header_bh);
 332	last_alloc = le64_to_cpu(header->sh_last_alloc);
 333	kunmap_atomic(kaddr);
 334
 335	nsegments = nilfs_sufile_get_nsegments(sufile);
 336	maxsegnum = sui->allocmax;
 337	segnum = last_alloc + 1;
 338	if (segnum < sui->allocmin || segnum > sui->allocmax)
 339		segnum = sui->allocmin;
 340
 341	for (cnt = 0; cnt < nsegments; cnt += nsus) {
 342		if (segnum > maxsegnum) {
 343			if (cnt < sui->allocmax - sui->allocmin + 1) {
 344				/*
 345				 * wrap around in the limited region.
 346				 * if allocation started from
 347				 * sui->allocmin, this never happens.
 348				 */
 349				segnum = sui->allocmin;
 350				maxsegnum = last_alloc;
 351			} else if (segnum > sui->allocmin &&
 352				   sui->allocmax + 1 < nsegments) {
 353				segnum = sui->allocmax + 1;
 354				maxsegnum = nsegments - 1;
 355			} else if (sui->allocmin > 0)  {
 356				segnum = 0;
 357				maxsegnum = sui->allocmin - 1;
 358			} else {
 359				break; /* never happens */
 360			}
 361		}
 362		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 363		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 364							   &su_bh);
 365		if (ret < 0)
 366			goto out_header;
 367		kaddr = kmap_atomic(su_bh->b_page);
 368		su = nilfs_sufile_block_get_segment_usage(
 369			sufile, segnum, su_bh, kaddr);
 370
 371		nsus = nilfs_sufile_segment_usages_in_block(
 372			sufile, segnum, maxsegnum);
 373		for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 374			if (!nilfs_segment_usage_clean(su))
 375				continue;
 376			/* found a clean segment */
 377			nilfs_segment_usage_set_dirty(su);
 378			kunmap_atomic(kaddr);
 379
 380			kaddr = kmap_atomic(header_bh->b_page);
 381			header = kaddr + bh_offset(header_bh);
 382			le64_add_cpu(&header->sh_ncleansegs, -1);
 383			le64_add_cpu(&header->sh_ndirtysegs, 1);
 384			header->sh_last_alloc = cpu_to_le64(segnum);
 385			kunmap_atomic(kaddr);
 386
 387			sui->ncleansegs--;
 388			mark_buffer_dirty(header_bh);
 389			mark_buffer_dirty(su_bh);
 390			nilfs_mdt_mark_dirty(sufile);
 391			brelse(su_bh);
 392			*segnump = segnum;
 393
 394			trace_nilfs2_segment_usage_allocated(sufile, segnum);
 395
 396			goto out_header;
 397		}
 398
 399		kunmap_atomic(kaddr);
 400		brelse(su_bh);
 401	}
 402
 403	/* no segments left */
 404	ret = -ENOSPC;
 405
 406 out_header:
 407	brelse(header_bh);
 408
 409 out_sem:
 410	up_write(&NILFS_MDT(sufile)->mi_sem);
 411	return ret;
 412}
 413
 414void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 415				 struct buffer_head *header_bh,
 416				 struct buffer_head *su_bh)
 417{
 418	struct nilfs_segment_usage *su;
 419	void *kaddr;
 420
 421	kaddr = kmap_atomic(su_bh->b_page);
 422	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 423	if (unlikely(!nilfs_segment_usage_clean(su))) {
 424		printk(KERN_WARNING "%s: segment %llu must be clean\n",
 425		       __func__, (unsigned long long)segnum);
 426		kunmap_atomic(kaddr);
 427		return;
 428	}
 429	nilfs_segment_usage_set_dirty(su);
 430	kunmap_atomic(kaddr);
 431
 432	nilfs_sufile_mod_counter(header_bh, -1, 1);
 433	NILFS_SUI(sufile)->ncleansegs--;
 434
 435	mark_buffer_dirty(su_bh);
 436	nilfs_mdt_mark_dirty(sufile);
 437}
 438
 439void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 440			   struct buffer_head *header_bh,
 441			   struct buffer_head *su_bh)
 442{
 443	struct nilfs_segment_usage *su;
 444	void *kaddr;
 445	int clean, dirty;
 446
 447	kaddr = kmap_atomic(su_bh->b_page);
 448	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 449	if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) &&
 450	    su->su_nblocks == cpu_to_le32(0)) {
 451		kunmap_atomic(kaddr);
 452		return;
 453	}
 454	clean = nilfs_segment_usage_clean(su);
 455	dirty = nilfs_segment_usage_dirty(su);
 456
 457	/* make the segment garbage */
 458	su->su_lastmod = cpu_to_le64(0);
 459	su->su_nblocks = cpu_to_le32(0);
 460	su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY);
 461	kunmap_atomic(kaddr);
 462
 463	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 464	NILFS_SUI(sufile)->ncleansegs -= clean;
 465
 466	mark_buffer_dirty(su_bh);
 467	nilfs_mdt_mark_dirty(sufile);
 468}
 469
 470void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 471			  struct buffer_head *header_bh,
 472			  struct buffer_head *su_bh)
 473{
 474	struct nilfs_segment_usage *su;
 475	void *kaddr;
 476	int sudirty;
 477
 478	kaddr = kmap_atomic(su_bh->b_page);
 479	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 480	if (nilfs_segment_usage_clean(su)) {
 481		printk(KERN_WARNING "%s: segment %llu is already clean\n",
 482		       __func__, (unsigned long long)segnum);
 483		kunmap_atomic(kaddr);
 484		return;
 485	}
 486	WARN_ON(nilfs_segment_usage_error(su));
 487	WARN_ON(!nilfs_segment_usage_dirty(su));
 488
 489	sudirty = nilfs_segment_usage_dirty(su);
 490	nilfs_segment_usage_set_clean(su);
 491	kunmap_atomic(kaddr);
 492	mark_buffer_dirty(su_bh);
 493
 494	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 495	NILFS_SUI(sufile)->ncleansegs++;
 496
 497	nilfs_mdt_mark_dirty(sufile);
 498
 499	trace_nilfs2_segment_usage_freed(sufile, segnum);
 500}
 501
 502/**
 503 * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 504 * @sufile: inode of segment usage file
 505 * @segnum: segment number
 506 */
 507int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 508{
 509	struct buffer_head *bh;
 
 
 510	int ret;
 511
 
 512	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 513	if (!ret) {
 514		mark_buffer_dirty(bh);
 515		nilfs_mdt_mark_dirty(sufile);
 
 
 
 
 516		brelse(bh);
 517	}
 
 518	return ret;
 519}
 520
 521/**
 522 * nilfs_sufile_set_segment_usage - set usage of a segment
 523 * @sufile: inode of segment usage file
 524 * @segnum: segment number
 525 * @nblocks: number of live blocks in the segment
 526 * @modtime: modification time (option)
 527 */
 528int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 529				   unsigned long nblocks, time_t modtime)
 530{
 531	struct buffer_head *bh;
 532	struct nilfs_segment_usage *su;
 533	void *kaddr;
 534	int ret;
 535
 536	down_write(&NILFS_MDT(sufile)->mi_sem);
 537	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 538	if (ret < 0)
 539		goto out_sem;
 540
 541	kaddr = kmap_atomic(bh->b_page);
 542	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 543	WARN_ON(nilfs_segment_usage_error(su));
 544	if (modtime)
 545		su->su_lastmod = cpu_to_le64(modtime);
 546	su->su_nblocks = cpu_to_le32(nblocks);
 547	kunmap_atomic(kaddr);
 548
 549	mark_buffer_dirty(bh);
 550	nilfs_mdt_mark_dirty(sufile);
 551	brelse(bh);
 552
 553 out_sem:
 554	up_write(&NILFS_MDT(sufile)->mi_sem);
 555	return ret;
 556}
 557
 558/**
 559 * nilfs_sufile_get_stat - get segment usage statistics
 560 * @sufile: inode of segment usage file
 561 * @stat: pointer to a structure of segment usage statistics
 562 *
 563 * Description: nilfs_sufile_get_stat() returns information about segment
 564 * usage.
 565 *
 566 * Return Value: On success, 0 is returned, and segment usage information is
 567 * stored in the place pointed by @stat. On error, one of the following
 568 * negative error codes is returned.
 569 *
 570 * %-EIO - I/O error.
 571 *
 572 * %-ENOMEM - Insufficient amount of memory available.
 573 */
 574int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 575{
 576	struct buffer_head *header_bh;
 577	struct nilfs_sufile_header *header;
 578	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 579	void *kaddr;
 580	int ret;
 581
 582	down_read(&NILFS_MDT(sufile)->mi_sem);
 583
 584	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 585	if (ret < 0)
 586		goto out_sem;
 587
 588	kaddr = kmap_atomic(header_bh->b_page);
 589	header = kaddr + bh_offset(header_bh);
 590	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 591	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 592	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 593	sustat->ss_ctime = nilfs->ns_ctime;
 594	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 595	spin_lock(&nilfs->ns_last_segment_lock);
 596	sustat->ss_prot_seq = nilfs->ns_prot_seq;
 597	spin_unlock(&nilfs->ns_last_segment_lock);
 598	kunmap_atomic(kaddr);
 599	brelse(header_bh);
 600
 601 out_sem:
 602	up_read(&NILFS_MDT(sufile)->mi_sem);
 603	return ret;
 604}
 605
 606void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 607			       struct buffer_head *header_bh,
 608			       struct buffer_head *su_bh)
 609{
 610	struct nilfs_segment_usage *su;
 611	void *kaddr;
 612	int suclean;
 613
 614	kaddr = kmap_atomic(su_bh->b_page);
 615	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 616	if (nilfs_segment_usage_error(su)) {
 617		kunmap_atomic(kaddr);
 618		return;
 619	}
 620	suclean = nilfs_segment_usage_clean(su);
 621	nilfs_segment_usage_set_error(su);
 622	kunmap_atomic(kaddr);
 623
 624	if (suclean) {
 625		nilfs_sufile_mod_counter(header_bh, -1, 0);
 626		NILFS_SUI(sufile)->ncleansegs--;
 627	}
 628	mark_buffer_dirty(su_bh);
 629	nilfs_mdt_mark_dirty(sufile);
 630}
 631
 632/**
 633  * nilfs_sufile_truncate_range - truncate range of segment array
 634  * @sufile: inode of segment usage file
 635  * @start: start segment number (inclusive)
 636  * @end: end segment number (inclusive)
 637  *
 638  * Return Value: On success, 0 is returned.  On error, one of the
 639  * following negative error codes is returned.
 640  *
 641  * %-EIO - I/O error.
 642  *
 643  * %-ENOMEM - Insufficient amount of memory available.
 644  *
 645  * %-EINVAL - Invalid number of segments specified
 646  *
 647  * %-EBUSY - Dirty or active segments are present in the range
 648  */
 649static int nilfs_sufile_truncate_range(struct inode *sufile,
 650				       __u64 start, __u64 end)
 651{
 652	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 653	struct buffer_head *header_bh;
 654	struct buffer_head *su_bh;
 655	struct nilfs_segment_usage *su, *su2;
 656	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 657	unsigned long segusages_per_block;
 658	unsigned long nsegs, ncleaned;
 659	__u64 segnum;
 660	void *kaddr;
 661	ssize_t n, nc;
 662	int ret;
 663	int j;
 664
 665	nsegs = nilfs_sufile_get_nsegments(sufile);
 666
 667	ret = -EINVAL;
 668	if (start > end || start >= nsegs)
 669		goto out;
 670
 671	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 672	if (ret < 0)
 673		goto out;
 674
 675	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 676	ncleaned = 0;
 677
 678	for (segnum = start; segnum <= end; segnum += n) {
 679		n = min_t(unsigned long,
 680			  segusages_per_block -
 681				  nilfs_sufile_get_offset(sufile, segnum),
 682			  end - segnum + 1);
 683		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 684							   &su_bh);
 685		if (ret < 0) {
 686			if (ret != -ENOENT)
 687				goto out_header;
 688			/* hole */
 689			continue;
 690		}
 691		kaddr = kmap_atomic(su_bh->b_page);
 692		su = nilfs_sufile_block_get_segment_usage(
 693			sufile, segnum, su_bh, kaddr);
 694		su2 = su;
 695		for (j = 0; j < n; j++, su = (void *)su + susz) {
 696			if ((le32_to_cpu(su->su_flags) &
 697			     ~(1UL << NILFS_SEGMENT_USAGE_ERROR)) ||
 698			    nilfs_segment_is_active(nilfs, segnum + j)) {
 699				ret = -EBUSY;
 700				kunmap_atomic(kaddr);
 701				brelse(su_bh);
 702				goto out_header;
 703			}
 704		}
 705		nc = 0;
 706		for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 707			if (nilfs_segment_usage_error(su)) {
 708				nilfs_segment_usage_set_clean(su);
 709				nc++;
 710			}
 711		}
 712		kunmap_atomic(kaddr);
 713		if (nc > 0) {
 714			mark_buffer_dirty(su_bh);
 715			ncleaned += nc;
 716		}
 717		brelse(su_bh);
 718
 719		if (n == segusages_per_block) {
 720			/* make hole */
 721			nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 722		}
 723	}
 724	ret = 0;
 725
 726out_header:
 727	if (ncleaned > 0) {
 728		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 729		nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 730		nilfs_mdt_mark_dirty(sufile);
 731	}
 732	brelse(header_bh);
 733out:
 734	return ret;
 735}
 736
 737/**
 738 * nilfs_sufile_resize - resize segment array
 739 * @sufile: inode of segment usage file
 740 * @newnsegs: new number of segments
 741 *
 742 * Return Value: On success, 0 is returned.  On error, one of the
 743 * following negative error codes is returned.
 744 *
 745 * %-EIO - I/O error.
 746 *
 747 * %-ENOMEM - Insufficient amount of memory available.
 748 *
 749 * %-ENOSPC - Enough free space is not left for shrinking
 750 *
 751 * %-EBUSY - Dirty or active segments exist in the region to be truncated
 752 */
 753int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 754{
 755	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 756	struct buffer_head *header_bh;
 757	struct nilfs_sufile_header *header;
 758	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 759	void *kaddr;
 760	unsigned long nsegs, nrsvsegs;
 761	int ret = 0;
 762
 763	down_write(&NILFS_MDT(sufile)->mi_sem);
 764
 765	nsegs = nilfs_sufile_get_nsegments(sufile);
 766	if (nsegs == newnsegs)
 767		goto out;
 768
 769	ret = -ENOSPC;
 770	nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 771	if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 772		goto out;
 773
 774	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 775	if (ret < 0)
 776		goto out;
 777
 778	if (newnsegs > nsegs) {
 779		sui->ncleansegs += newnsegs - nsegs;
 780	} else /* newnsegs < nsegs */ {
 781		ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 782		if (ret < 0)
 783			goto out_header;
 784
 785		sui->ncleansegs -= nsegs - newnsegs;
 786	}
 787
 788	kaddr = kmap_atomic(header_bh->b_page);
 789	header = kaddr + bh_offset(header_bh);
 790	header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 791	kunmap_atomic(kaddr);
 792
 793	mark_buffer_dirty(header_bh);
 794	nilfs_mdt_mark_dirty(sufile);
 795	nilfs_set_nsegments(nilfs, newnsegs);
 796
 797out_header:
 798	brelse(header_bh);
 799out:
 800	up_write(&NILFS_MDT(sufile)->mi_sem);
 801	return ret;
 802}
 803
 804/**
 805 * nilfs_sufile_get_suinfo -
 806 * @sufile: inode of segment usage file
 807 * @segnum: segment number to start looking
 808 * @buf: array of suinfo
 809 * @sisz: byte size of suinfo
 810 * @nsi: size of suinfo array
 811 *
 812 * Description:
 813 *
 814 * Return Value: On success, 0 is returned and .... On error, one of the
 815 * following negative error codes is returned.
 816 *
 817 * %-EIO - I/O error.
 818 *
 819 * %-ENOMEM - Insufficient amount of memory available.
 820 */
 821ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 822				unsigned sisz, size_t nsi)
 823{
 824	struct buffer_head *su_bh;
 825	struct nilfs_segment_usage *su;
 826	struct nilfs_suinfo *si = buf;
 827	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 828	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 829	void *kaddr;
 830	unsigned long nsegs, segusages_per_block;
 831	ssize_t n;
 832	int ret, i, j;
 833
 834	down_read(&NILFS_MDT(sufile)->mi_sem);
 835
 836	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 837	nsegs = min_t(unsigned long,
 838		      nilfs_sufile_get_nsegments(sufile) - segnum,
 839		      nsi);
 840	for (i = 0; i < nsegs; i += n, segnum += n) {
 841		n = min_t(unsigned long,
 842			  segusages_per_block -
 843				  nilfs_sufile_get_offset(sufile, segnum),
 844			  nsegs - i);
 845		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 846							   &su_bh);
 847		if (ret < 0) {
 848			if (ret != -ENOENT)
 849				goto out;
 850			/* hole */
 851			memset(si, 0, sisz * n);
 852			si = (void *)si + sisz * n;
 853			continue;
 854		}
 855
 856		kaddr = kmap_atomic(su_bh->b_page);
 857		su = nilfs_sufile_block_get_segment_usage(
 858			sufile, segnum, su_bh, kaddr);
 859		for (j = 0; j < n;
 860		     j++, su = (void *)su + susz, si = (void *)si + sisz) {
 861			si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 862			si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 863			si->sui_flags = le32_to_cpu(su->su_flags) &
 864				~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
 865			if (nilfs_segment_is_active(nilfs, segnum + j))
 866				si->sui_flags |=
 867					(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
 868		}
 869		kunmap_atomic(kaddr);
 870		brelse(su_bh);
 871	}
 872	ret = nsegs;
 873
 874 out:
 875	up_read(&NILFS_MDT(sufile)->mi_sem);
 876	return ret;
 877}
 878
 879/**
 880 * nilfs_sufile_set_suinfo - sets segment usage info
 881 * @sufile: inode of segment usage file
 882 * @buf: array of suinfo_update
 883 * @supsz: byte size of suinfo_update
 884 * @nsup: size of suinfo_update array
 885 *
 886 * Description: Takes an array of nilfs_suinfo_update structs and updates
 887 * segment usage accordingly. Only the fields indicated by the sup_flags
 888 * are updated.
 889 *
 890 * Return Value: On success, 0 is returned. On error, one of the
 891 * following negative error codes is returned.
 892 *
 893 * %-EIO - I/O error.
 894 *
 895 * %-ENOMEM - Insufficient amount of memory available.
 896 *
 897 * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 898 */
 899ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 900				unsigned supsz, size_t nsup)
 901{
 902	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 903	struct buffer_head *header_bh, *bh;
 904	struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 905	struct nilfs_segment_usage *su;
 906	void *kaddr;
 907	unsigned long blkoff, prev_blkoff;
 908	int cleansi, cleansu, dirtysi, dirtysu;
 909	long ncleaned = 0, ndirtied = 0;
 910	int ret = 0;
 911
 912	if (unlikely(nsup == 0))
 913		return ret;
 914
 915	for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 916		if (sup->sup_segnum >= nilfs->ns_nsegments
 917			|| (sup->sup_flags &
 918				(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 919			|| (nilfs_suinfo_update_nblocks(sup) &&
 920				sup->sup_sui.sui_nblocks >
 921				nilfs->ns_blocks_per_segment))
 922			return -EINVAL;
 923	}
 924
 925	down_write(&NILFS_MDT(sufile)->mi_sem);
 926
 927	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 928	if (ret < 0)
 929		goto out_sem;
 930
 931	sup = buf;
 932	blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 933	ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 934	if (ret < 0)
 935		goto out_header;
 936
 937	for (;;) {
 938		kaddr = kmap_atomic(bh->b_page);
 939		su = nilfs_sufile_block_get_segment_usage(
 940			sufile, sup->sup_segnum, bh, kaddr);
 941
 942		if (nilfs_suinfo_update_lastmod(sup))
 943			su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 944
 945		if (nilfs_suinfo_update_nblocks(sup))
 946			su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 947
 948		if (nilfs_suinfo_update_flags(sup)) {
 949			/*
 950			 * Active flag is a virtual flag projected by running
 951			 * nilfs kernel code - drop it not to write it to
 952			 * disk.
 953			 */
 954			sup->sup_sui.sui_flags &=
 955					~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
 956
 957			cleansi = nilfs_suinfo_clean(&sup->sup_sui);
 958			cleansu = nilfs_segment_usage_clean(su);
 959			dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
 960			dirtysu = nilfs_segment_usage_dirty(su);
 961
 962			if (cleansi && !cleansu)
 963				++ncleaned;
 964			else if (!cleansi && cleansu)
 965				--ncleaned;
 966
 967			if (dirtysi && !dirtysu)
 968				++ndirtied;
 969			else if (!dirtysi && dirtysu)
 970				--ndirtied;
 971
 972			su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
 973		}
 974
 975		kunmap_atomic(kaddr);
 976
 977		sup = (void *)sup + supsz;
 978		if (sup >= supend)
 979			break;
 980
 981		prev_blkoff = blkoff;
 982		blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 983		if (blkoff == prev_blkoff)
 984			continue;
 985
 986		/* get different block */
 987		mark_buffer_dirty(bh);
 988		put_bh(bh);
 989		ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 990		if (unlikely(ret < 0))
 991			goto out_mark;
 992	}
 993	mark_buffer_dirty(bh);
 994	put_bh(bh);
 995
 996 out_mark:
 997	if (ncleaned || ndirtied) {
 998		nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
 999				(u64)ndirtied);
1000		NILFS_SUI(sufile)->ncleansegs += ncleaned;
1001	}
1002	nilfs_mdt_mark_dirty(sufile);
1003 out_header:
1004	put_bh(header_bh);
1005 out_sem:
1006	up_write(&NILFS_MDT(sufile)->mi_sem);
1007	return ret;
1008}
1009
1010/**
1011 * nilfs_sufile_trim_fs() - trim ioctl handle function
1012 * @sufile: inode of segment usage file
1013 * @range: fstrim_range structure
1014 *
1015 * start:	First Byte to trim
1016 * len:		number of Bytes to trim from start
1017 * minlen:	minimum extent length in Bytes
1018 *
1019 * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1020 * from start to start+len. start is rounded up to the next block boundary
1021 * and start+len is rounded down. For each clean segment blkdev_issue_discard
1022 * function is invoked.
1023 *
1024 * Return Value: On success, 0 is returned or negative error code, otherwise.
1025 */
1026int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1027{
1028	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1029	struct buffer_head *su_bh;
1030	struct nilfs_segment_usage *su;
1031	void *kaddr;
1032	size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1033	sector_t seg_start, seg_end, start_block, end_block;
1034	sector_t start = 0, nblocks = 0;
1035	u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1036	int ret = 0;
1037	unsigned int sects_per_block;
1038
1039	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1040			bdev_logical_block_size(nilfs->ns_bdev);
1041	len = range->len >> nilfs->ns_blocksize_bits;
1042	minlen = range->minlen >> nilfs->ns_blocksize_bits;
1043	max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1044
1045	if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1046		return -EINVAL;
1047
1048	start_block = (range->start + nilfs->ns_blocksize - 1) >>
1049			nilfs->ns_blocksize_bits;
1050
1051	/*
1052	 * range->len can be very large (actually, it is set to
1053	 * ULLONG_MAX by default) - truncate upper end of the range
1054	 * carefully so as not to overflow.
1055	 */
1056	if (max_blocks - start_block < len)
1057		end_block = max_blocks - 1;
1058	else
1059		end_block = start_block + len - 1;
1060
1061	segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1062	segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1063
1064	down_read(&NILFS_MDT(sufile)->mi_sem);
1065
1066	while (segnum <= segnum_end) {
1067		n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1068				segnum_end);
1069
1070		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1071							   &su_bh);
1072		if (ret < 0) {
1073			if (ret != -ENOENT)
1074				goto out_sem;
1075			/* hole */
1076			segnum += n;
1077			continue;
1078		}
1079
1080		kaddr = kmap_atomic(su_bh->b_page);
1081		su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1082				su_bh, kaddr);
1083		for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1084			if (!nilfs_segment_usage_clean(su))
1085				continue;
1086
1087			nilfs_get_segment_range(nilfs, segnum, &seg_start,
1088						&seg_end);
1089
1090			if (!nblocks) {
1091				/* start new extent */
1092				start = seg_start;
1093				nblocks = seg_end - seg_start + 1;
1094				continue;
1095			}
1096
1097			if (start + nblocks == seg_start) {
1098				/* add to previous extent */
1099				nblocks += seg_end - seg_start + 1;
1100				continue;
1101			}
1102
1103			/* discard previous extent */
1104			if (start < start_block) {
1105				nblocks -= start_block - start;
1106				start = start_block;
1107			}
1108
1109			if (nblocks >= minlen) {
1110				kunmap_atomic(kaddr);
1111
1112				ret = blkdev_issue_discard(nilfs->ns_bdev,
1113						start * sects_per_block,
1114						nblocks * sects_per_block,
1115						GFP_NOFS, 0);
1116				if (ret < 0) {
1117					put_bh(su_bh);
1118					goto out_sem;
1119				}
1120
1121				ndiscarded += nblocks;
1122				kaddr = kmap_atomic(su_bh->b_page);
1123				su = nilfs_sufile_block_get_segment_usage(
1124					sufile, segnum, su_bh, kaddr);
1125			}
1126
1127			/* start new extent */
1128			start = seg_start;
1129			nblocks = seg_end - seg_start + 1;
1130		}
1131		kunmap_atomic(kaddr);
1132		put_bh(su_bh);
1133	}
1134
1135
1136	if (nblocks) {
1137		/* discard last extent */
1138		if (start < start_block) {
1139			nblocks -= start_block - start;
1140			start = start_block;
1141		}
1142		if (start + nblocks > end_block + 1)
1143			nblocks = end_block - start + 1;
1144
1145		if (nblocks >= minlen) {
1146			ret = blkdev_issue_discard(nilfs->ns_bdev,
1147					start * sects_per_block,
1148					nblocks * sects_per_block,
1149					GFP_NOFS, 0);
1150			if (!ret)
1151				ndiscarded += nblocks;
1152		}
1153	}
1154
1155out_sem:
1156	up_read(&NILFS_MDT(sufile)->mi_sem);
1157
1158	range->len = ndiscarded << nilfs->ns_blocksize_bits;
1159	return ret;
1160}
1161
1162/**
1163 * nilfs_sufile_read - read or get sufile inode
1164 * @sb: super block instance
1165 * @susize: size of a segment usage entry
1166 * @raw_inode: on-disk sufile inode
1167 * @inodep: buffer to store the inode
1168 */
1169int nilfs_sufile_read(struct super_block *sb, size_t susize,
1170		      struct nilfs_inode *raw_inode, struct inode **inodep)
1171{
1172	struct inode *sufile;
1173	struct nilfs_sufile_info *sui;
1174	struct buffer_head *header_bh;
1175	struct nilfs_sufile_header *header;
1176	void *kaddr;
1177	int err;
1178
1179	if (susize > sb->s_blocksize) {
1180		printk(KERN_ERR
1181		       "NILFS: too large segment usage size: %zu bytes.\n",
1182		       susize);
1183		return -EINVAL;
1184	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1185		printk(KERN_ERR
1186		       "NILFS: too small segment usage size: %zu bytes.\n",
1187		       susize);
1188		return -EINVAL;
1189	}
1190
1191	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1192	if (unlikely(!sufile))
1193		return -ENOMEM;
1194	if (!(sufile->i_state & I_NEW))
1195		goto out;
1196
1197	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1198	if (err)
1199		goto failed;
1200
1201	nilfs_mdt_set_entry_size(sufile, susize,
1202				 sizeof(struct nilfs_sufile_header));
1203
1204	err = nilfs_read_inode_common(sufile, raw_inode);
1205	if (err)
1206		goto failed;
1207
1208	err = nilfs_sufile_get_header_block(sufile, &header_bh);
1209	if (err)
1210		goto failed;
1211
1212	sui = NILFS_SUI(sufile);
1213	kaddr = kmap_atomic(header_bh->b_page);
1214	header = kaddr + bh_offset(header_bh);
1215	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1216	kunmap_atomic(kaddr);
1217	brelse(header_bh);
1218
1219	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1220	sui->allocmin = 0;
1221
1222	unlock_new_inode(sufile);
1223 out:
1224	*inodep = sufile;
1225	return 0;
1226 failed:
1227	iget_failed(sufile);
1228	return err;
1229}