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v4.17
 
   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 * Written by Koji Sato.
  17 * Revised by Ryusuke Konishi.
  18 */
  19
  20#include <linux/kernel.h>
  21#include <linux/fs.h>
  22#include <linux/string.h>
  23#include <linux/buffer_head.h>
  24#include <linux/errno.h>
  25#include "mdt.h"
  26#include "sufile.h"
  27
  28#include <trace/events/nilfs2.h>
  29
  30/**
  31 * struct nilfs_sufile_info - on-memory private data of sufile
  32 * @mi: on-memory private data of metadata file
  33 * @ncleansegs: number of clean segments
  34 * @allocmin: lower limit of allocatable segment range
  35 * @allocmax: upper limit of allocatable segment range
  36 */
  37struct nilfs_sufile_info {
  38	struct nilfs_mdt_info mi;
  39	unsigned long ncleansegs;/* number of clean segments */
  40	__u64 allocmin;		/* lower limit of allocatable segment range */
  41	__u64 allocmax;		/* upper limit of allocatable segment range */
  42};
  43
  44static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
  45{
  46	return (struct nilfs_sufile_info *)NILFS_MDT(sufile);
  47}
  48
  49static inline unsigned long
  50nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
  51{
  52	return NILFS_MDT(sufile)->mi_entries_per_block;
  53}
  54
  55static unsigned long
  56nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
  57{
  58	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  59
  60	do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  61	return (unsigned long)t;
  62}
  63
  64static unsigned long
  65nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
  66{
  67	__u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
  68
  69	return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
  70}
  71
  72static unsigned long
  73nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
  74				     __u64 max)
  75{
  76	return min_t(unsigned long,
  77		     nilfs_sufile_segment_usages_per_block(sufile) -
  78		     nilfs_sufile_get_offset(sufile, curr),
  79		     max - curr + 1);
  80}
  81
  82static struct nilfs_segment_usage *
  83nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
  84				     struct buffer_head *bh, void *kaddr)
  85{
  86	return kaddr + bh_offset(bh) +
  87		nilfs_sufile_get_offset(sufile, segnum) *
  88		NILFS_MDT(sufile)->mi_entry_size;
  89}
  90
  91static inline int nilfs_sufile_get_header_block(struct inode *sufile,
  92						struct buffer_head **bhp)
  93{
  94	return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  95}
  96
  97static inline int
  98nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
  99				     int create, struct buffer_head **bhp)
 100{
 101	return nilfs_mdt_get_block(sufile,
 102				   nilfs_sufile_get_blkoff(sufile, segnum),
 103				   create, NULL, bhp);
 104}
 105
 106static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
 107						   __u64 segnum)
 108{
 109	return nilfs_mdt_delete_block(sufile,
 110				      nilfs_sufile_get_blkoff(sufile, segnum));
 111}
 112
 113static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
 114				     u64 ncleanadd, u64 ndirtyadd)
 115{
 116	struct nilfs_sufile_header *header;
 117	void *kaddr;
 118
 119	kaddr = kmap_atomic(header_bh->b_page);
 120	header = kaddr + bh_offset(header_bh);
 121	le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
 122	le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
 123	kunmap_atomic(kaddr);
 124
 125	mark_buffer_dirty(header_bh);
 126}
 127
 128/**
 129 * nilfs_sufile_get_ncleansegs - return the number of clean segments
 130 * @sufile: inode of segment usage file
 131 */
 132unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
 133{
 134	return NILFS_SUI(sufile)->ncleansegs;
 135}
 136
 137/**
 138 * nilfs_sufile_updatev - modify multiple segment usages at a time
 139 * @sufile: inode of segment usage file
 140 * @segnumv: array of segment numbers
 141 * @nsegs: size of @segnumv array
 142 * @create: creation flag
 143 * @ndone: place to store number of modified segments on @segnumv
 144 * @dofunc: primitive operation for the update
 145 *
 146 * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
 147 * against the given array of segments.  The @dofunc is called with
 148 * buffers of a header block and the sufile block in which the target
 149 * segment usage entry is contained.  If @ndone is given, the number
 150 * of successfully modified segments from the head is stored in the
 151 * place @ndone points to.
 152 *
 153 * Return Value: On success, zero is returned.  On error, one of the
 154 * following negative error codes is returned.
 155 *
 156 * %-EIO - I/O error.
 157 *
 158 * %-ENOMEM - Insufficient amount of memory available.
 159 *
 160 * %-ENOENT - Given segment usage is in hole block (may be returned if
 161 *            @create is zero)
 162 *
 163 * %-EINVAL - Invalid segment usage number
 164 */
 165int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
 166			 int create, size_t *ndone,
 167			 void (*dofunc)(struct inode *, __u64,
 168					struct buffer_head *,
 169					struct buffer_head *))
 170{
 171	struct buffer_head *header_bh, *bh;
 172	unsigned long blkoff, prev_blkoff;
 173	__u64 *seg;
 174	size_t nerr = 0, n = 0;
 175	int ret = 0;
 176
 177	if (unlikely(nsegs == 0))
 178		goto out;
 179
 180	down_write(&NILFS_MDT(sufile)->mi_sem);
 181	for (seg = segnumv; seg < segnumv + nsegs; seg++) {
 182		if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
 183			nilfs_msg(sufile->i_sb, KERN_WARNING,
 184				  "%s: invalid segment number: %llu",
 185				  __func__, (unsigned long long)*seg);
 186			nerr++;
 187		}
 188	}
 189	if (nerr > 0) {
 190		ret = -EINVAL;
 191		goto out_sem;
 192	}
 193
 194	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 195	if (ret < 0)
 196		goto out_sem;
 197
 198	seg = segnumv;
 199	blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 200	ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 201	if (ret < 0)
 202		goto out_header;
 203
 204	for (;;) {
 205		dofunc(sufile, *seg, header_bh, bh);
 206
 207		if (++seg >= segnumv + nsegs)
 208			break;
 209		prev_blkoff = blkoff;
 210		blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 211		if (blkoff == prev_blkoff)
 212			continue;
 213
 214		/* get different block */
 215		brelse(bh);
 216		ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 217		if (unlikely(ret < 0))
 218			goto out_header;
 219	}
 220	brelse(bh);
 221
 222 out_header:
 223	n = seg - segnumv;
 224	brelse(header_bh);
 225 out_sem:
 226	up_write(&NILFS_MDT(sufile)->mi_sem);
 227 out:
 228	if (ndone)
 229		*ndone = n;
 230	return ret;
 231}
 232
 233int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
 234			void (*dofunc)(struct inode *, __u64,
 235				       struct buffer_head *,
 236				       struct buffer_head *))
 237{
 238	struct buffer_head *header_bh, *bh;
 239	int ret;
 240
 241	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
 242		nilfs_msg(sufile->i_sb, KERN_WARNING,
 243			  "%s: invalid segment number: %llu",
 244			  __func__, (unsigned long long)segnum);
 245		return -EINVAL;
 246	}
 247	down_write(&NILFS_MDT(sufile)->mi_sem);
 248
 249	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 250	if (ret < 0)
 251		goto out_sem;
 252
 253	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 254	if (!ret) {
 255		dofunc(sufile, segnum, header_bh, bh);
 256		brelse(bh);
 257	}
 258	brelse(header_bh);
 259
 260 out_sem:
 261	up_write(&NILFS_MDT(sufile)->mi_sem);
 262	return ret;
 263}
 264
 265/**
 266 * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 267 * @sufile: inode of segment usage file
 268 * @start: minimum segment number of allocatable region (inclusive)
 269 * @end: maximum segment number of allocatable region (inclusive)
 270 *
 271 * Return Value: On success, 0 is returned.  On error, one of the
 272 * following negative error codes is returned.
 273 *
 274 * %-ERANGE - invalid segment region
 275 */
 276int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 277{
 278	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 279	__u64 nsegs;
 280	int ret = -ERANGE;
 281
 282	down_write(&NILFS_MDT(sufile)->mi_sem);
 283	nsegs = nilfs_sufile_get_nsegments(sufile);
 284
 285	if (start <= end && end < nsegs) {
 286		sui->allocmin = start;
 287		sui->allocmax = end;
 288		ret = 0;
 289	}
 290	up_write(&NILFS_MDT(sufile)->mi_sem);
 291	return ret;
 292}
 293
 294/**
 295 * nilfs_sufile_alloc - allocate a segment
 296 * @sufile: inode of segment usage file
 297 * @segnump: pointer to segment number
 298 *
 299 * Description: nilfs_sufile_alloc() allocates a clean segment.
 300 *
 301 * Return Value: On success, 0 is returned and the segment number of the
 302 * allocated segment is stored in the place pointed by @segnump. On error, one
 303 * of the following negative error codes is returned.
 304 *
 305 * %-EIO - I/O error.
 306 *
 307 * %-ENOMEM - Insufficient amount of memory available.
 308 *
 309 * %-ENOSPC - No clean segment left.
 310 */
 311int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 312{
 313	struct buffer_head *header_bh, *su_bh;
 314	struct nilfs_sufile_header *header;
 315	struct nilfs_segment_usage *su;
 316	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 317	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 318	__u64 segnum, maxsegnum, last_alloc;
 319	void *kaddr;
 320	unsigned long nsegments, nsus, cnt;
 321	int ret, j;
 322
 323	down_write(&NILFS_MDT(sufile)->mi_sem);
 324
 325	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 326	if (ret < 0)
 327		goto out_sem;
 328	kaddr = kmap_atomic(header_bh->b_page);
 329	header = kaddr + bh_offset(header_bh);
 330	last_alloc = le64_to_cpu(header->sh_last_alloc);
 331	kunmap_atomic(kaddr);
 332
 333	nsegments = nilfs_sufile_get_nsegments(sufile);
 334	maxsegnum = sui->allocmax;
 335	segnum = last_alloc + 1;
 336	if (segnum < sui->allocmin || segnum > sui->allocmax)
 337		segnum = sui->allocmin;
 338
 339	for (cnt = 0; cnt < nsegments; cnt += nsus) {
 340		if (segnum > maxsegnum) {
 341			if (cnt < sui->allocmax - sui->allocmin + 1) {
 342				/*
 343				 * wrap around in the limited region.
 344				 * if allocation started from
 345				 * sui->allocmin, this never happens.
 346				 */
 347				segnum = sui->allocmin;
 348				maxsegnum = last_alloc;
 349			} else if (segnum > sui->allocmin &&
 350				   sui->allocmax + 1 < nsegments) {
 351				segnum = sui->allocmax + 1;
 352				maxsegnum = nsegments - 1;
 353			} else if (sui->allocmin > 0)  {
 354				segnum = 0;
 355				maxsegnum = sui->allocmin - 1;
 356			} else {
 357				break; /* never happens */
 358			}
 359		}
 360		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 361		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 362							   &su_bh);
 363		if (ret < 0)
 364			goto out_header;
 365		kaddr = kmap_atomic(su_bh->b_page);
 366		su = nilfs_sufile_block_get_segment_usage(
 367			sufile, segnum, su_bh, kaddr);
 368
 369		nsus = nilfs_sufile_segment_usages_in_block(
 370			sufile, segnum, maxsegnum);
 371		for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 372			if (!nilfs_segment_usage_clean(su))
 373				continue;
 374			/* found a clean segment */
 375			nilfs_segment_usage_set_dirty(su);
 376			kunmap_atomic(kaddr);
 377
 378			kaddr = kmap_atomic(header_bh->b_page);
 379			header = kaddr + bh_offset(header_bh);
 380			le64_add_cpu(&header->sh_ncleansegs, -1);
 381			le64_add_cpu(&header->sh_ndirtysegs, 1);
 382			header->sh_last_alloc = cpu_to_le64(segnum);
 383			kunmap_atomic(kaddr);
 384
 385			sui->ncleansegs--;
 386			mark_buffer_dirty(header_bh);
 387			mark_buffer_dirty(su_bh);
 388			nilfs_mdt_mark_dirty(sufile);
 389			brelse(su_bh);
 390			*segnump = segnum;
 391
 392			trace_nilfs2_segment_usage_allocated(sufile, segnum);
 393
 394			goto out_header;
 395		}
 396
 397		kunmap_atomic(kaddr);
 398		brelse(su_bh);
 399	}
 400
 401	/* no segments left */
 402	ret = -ENOSPC;
 403
 404 out_header:
 405	brelse(header_bh);
 406
 407 out_sem:
 408	up_write(&NILFS_MDT(sufile)->mi_sem);
 409	return ret;
 410}
 411
 412void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 413				 struct buffer_head *header_bh,
 414				 struct buffer_head *su_bh)
 415{
 416	struct nilfs_segment_usage *su;
 417	void *kaddr;
 418
 419	kaddr = kmap_atomic(su_bh->b_page);
 420	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 421	if (unlikely(!nilfs_segment_usage_clean(su))) {
 422		nilfs_msg(sufile->i_sb, KERN_WARNING,
 423			  "%s: segment %llu must be clean", __func__,
 424			  (unsigned long long)segnum);
 425		kunmap_atomic(kaddr);
 426		return;
 427	}
 428	nilfs_segment_usage_set_dirty(su);
 429	kunmap_atomic(kaddr);
 430
 431	nilfs_sufile_mod_counter(header_bh, -1, 1);
 432	NILFS_SUI(sufile)->ncleansegs--;
 433
 434	mark_buffer_dirty(su_bh);
 435	nilfs_mdt_mark_dirty(sufile);
 436}
 437
 438void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 439			   struct buffer_head *header_bh,
 440			   struct buffer_head *su_bh)
 441{
 442	struct nilfs_segment_usage *su;
 443	void *kaddr;
 444	int clean, dirty;
 445
 446	kaddr = kmap_atomic(su_bh->b_page);
 447	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 448	if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
 449	    su->su_nblocks == cpu_to_le32(0)) {
 450		kunmap_atomic(kaddr);
 451		return;
 452	}
 453	clean = nilfs_segment_usage_clean(su);
 454	dirty = nilfs_segment_usage_dirty(su);
 455
 456	/* make the segment garbage */
 457	su->su_lastmod = cpu_to_le64(0);
 458	su->su_nblocks = cpu_to_le32(0);
 459	su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
 460	kunmap_atomic(kaddr);
 461
 462	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 463	NILFS_SUI(sufile)->ncleansegs -= clean;
 464
 465	mark_buffer_dirty(su_bh);
 466	nilfs_mdt_mark_dirty(sufile);
 467}
 468
 469void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 470			  struct buffer_head *header_bh,
 471			  struct buffer_head *su_bh)
 472{
 473	struct nilfs_segment_usage *su;
 474	void *kaddr;
 475	int sudirty;
 476
 477	kaddr = kmap_atomic(su_bh->b_page);
 478	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 479	if (nilfs_segment_usage_clean(su)) {
 480		nilfs_msg(sufile->i_sb, KERN_WARNING,
 481			  "%s: segment %llu is already clean",
 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, time64_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			     ~BIT(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 int 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				~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 865			if (nilfs_segment_is_active(nilfs, segnum + j))
 866				si->sui_flags |=
 867					BIT(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 int 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					~BIT(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		nilfs_msg(sb, KERN_ERR,
1181			  "too large segment usage size: %zu bytes", susize);
1182		return -EINVAL;
1183	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1184		nilfs_msg(sb, KERN_ERR,
1185			  "too small segment usage size: %zu bytes", susize);
1186		return -EINVAL;
1187	}
1188
1189	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1190	if (unlikely(!sufile))
1191		return -ENOMEM;
1192	if (!(sufile->i_state & I_NEW))
1193		goto out;
1194
1195	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1196	if (err)
1197		goto failed;
1198
1199	nilfs_mdt_set_entry_size(sufile, susize,
1200				 sizeof(struct nilfs_sufile_header));
1201
1202	err = nilfs_read_inode_common(sufile, raw_inode);
1203	if (err)
1204		goto failed;
1205
1206	err = nilfs_sufile_get_header_block(sufile, &header_bh);
1207	if (err)
1208		goto failed;
1209
1210	sui = NILFS_SUI(sufile);
1211	kaddr = kmap_atomic(header_bh->b_page);
1212	header = kaddr + bh_offset(header_bh);
1213	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1214	kunmap_atomic(kaddr);
1215	brelse(header_bh);
1216
1217	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1218	sui->allocmin = 0;
1219
1220	unlock_new_inode(sufile);
1221 out:
1222	*inodep = sufile;
1223	return 0;
1224 failed:
1225	iget_failed(sufile);
1226	return err;
1227}
v5.4
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * sufile.c - 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_msg(sufile->i_sb, KERN_WARNING,
 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_msg(sufile->i_sb, KERN_WARNING,
 234			  "%s: invalid segment number: %llu",
 235			  __func__, (unsigned long long)segnum);
 236		return -EINVAL;
 237	}
 238	down_write(&NILFS_MDT(sufile)->mi_sem);
 239
 240	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 241	if (ret < 0)
 242		goto out_sem;
 243
 244	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 245	if (!ret) {
 246		dofunc(sufile, segnum, header_bh, bh);
 247		brelse(bh);
 248	}
 249	brelse(header_bh);
 250
 251 out_sem:
 252	up_write(&NILFS_MDT(sufile)->mi_sem);
 253	return ret;
 254}
 255
 256/**
 257 * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 258 * @sufile: inode of segment usage file
 259 * @start: minimum segment number of allocatable region (inclusive)
 260 * @end: maximum segment number of allocatable region (inclusive)
 261 *
 262 * Return Value: On success, 0 is returned.  On error, one of the
 263 * following negative error codes is returned.
 264 *
 265 * %-ERANGE - invalid segment region
 266 */
 267int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 268{
 269	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 270	__u64 nsegs;
 271	int ret = -ERANGE;
 272
 273	down_write(&NILFS_MDT(sufile)->mi_sem);
 274	nsegs = nilfs_sufile_get_nsegments(sufile);
 275
 276	if (start <= end && end < nsegs) {
 277		sui->allocmin = start;
 278		sui->allocmax = end;
 279		ret = 0;
 280	}
 281	up_write(&NILFS_MDT(sufile)->mi_sem);
 282	return ret;
 283}
 284
 285/**
 286 * nilfs_sufile_alloc - allocate a segment
 287 * @sufile: inode of segment usage file
 288 * @segnump: pointer to segment number
 289 *
 290 * Description: nilfs_sufile_alloc() allocates a clean segment.
 291 *
 292 * Return Value: On success, 0 is returned and the segment number of the
 293 * allocated segment is stored in the place pointed by @segnump. On error, one
 294 * of the following negative error codes is returned.
 295 *
 296 * %-EIO - I/O error.
 297 *
 298 * %-ENOMEM - Insufficient amount of memory available.
 299 *
 300 * %-ENOSPC - No clean segment left.
 301 */
 302int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 303{
 304	struct buffer_head *header_bh, *su_bh;
 305	struct nilfs_sufile_header *header;
 306	struct nilfs_segment_usage *su;
 307	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 308	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 309	__u64 segnum, maxsegnum, last_alloc;
 310	void *kaddr;
 311	unsigned long nsegments, nsus, cnt;
 312	int ret, j;
 313
 314	down_write(&NILFS_MDT(sufile)->mi_sem);
 315
 316	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 317	if (ret < 0)
 318		goto out_sem;
 319	kaddr = kmap_atomic(header_bh->b_page);
 320	header = kaddr + bh_offset(header_bh);
 321	last_alloc = le64_to_cpu(header->sh_last_alloc);
 322	kunmap_atomic(kaddr);
 323
 324	nsegments = nilfs_sufile_get_nsegments(sufile);
 325	maxsegnum = sui->allocmax;
 326	segnum = last_alloc + 1;
 327	if (segnum < sui->allocmin || segnum > sui->allocmax)
 328		segnum = sui->allocmin;
 329
 330	for (cnt = 0; cnt < nsegments; cnt += nsus) {
 331		if (segnum > maxsegnum) {
 332			if (cnt < sui->allocmax - sui->allocmin + 1) {
 333				/*
 334				 * wrap around in the limited region.
 335				 * if allocation started from
 336				 * sui->allocmin, this never happens.
 337				 */
 338				segnum = sui->allocmin;
 339				maxsegnum = last_alloc;
 340			} else if (segnum > sui->allocmin &&
 341				   sui->allocmax + 1 < nsegments) {
 342				segnum = sui->allocmax + 1;
 343				maxsegnum = nsegments - 1;
 344			} else if (sui->allocmin > 0)  {
 345				segnum = 0;
 346				maxsegnum = sui->allocmin - 1;
 347			} else {
 348				break; /* never happens */
 349			}
 350		}
 351		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 352		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 353							   &su_bh);
 354		if (ret < 0)
 355			goto out_header;
 356		kaddr = kmap_atomic(su_bh->b_page);
 357		su = nilfs_sufile_block_get_segment_usage(
 358			sufile, segnum, su_bh, kaddr);
 359
 360		nsus = nilfs_sufile_segment_usages_in_block(
 361			sufile, segnum, maxsegnum);
 362		for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 363			if (!nilfs_segment_usage_clean(su))
 364				continue;
 365			/* found a clean segment */
 366			nilfs_segment_usage_set_dirty(su);
 367			kunmap_atomic(kaddr);
 368
 369			kaddr = kmap_atomic(header_bh->b_page);
 370			header = kaddr + bh_offset(header_bh);
 371			le64_add_cpu(&header->sh_ncleansegs, -1);
 372			le64_add_cpu(&header->sh_ndirtysegs, 1);
 373			header->sh_last_alloc = cpu_to_le64(segnum);
 374			kunmap_atomic(kaddr);
 375
 376			sui->ncleansegs--;
 377			mark_buffer_dirty(header_bh);
 378			mark_buffer_dirty(su_bh);
 379			nilfs_mdt_mark_dirty(sufile);
 380			brelse(su_bh);
 381			*segnump = segnum;
 382
 383			trace_nilfs2_segment_usage_allocated(sufile, segnum);
 384
 385			goto out_header;
 386		}
 387
 388		kunmap_atomic(kaddr);
 389		brelse(su_bh);
 390	}
 391
 392	/* no segments left */
 393	ret = -ENOSPC;
 394
 395 out_header:
 396	brelse(header_bh);
 397
 398 out_sem:
 399	up_write(&NILFS_MDT(sufile)->mi_sem);
 400	return ret;
 401}
 402
 403void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 404				 struct buffer_head *header_bh,
 405				 struct buffer_head *su_bh)
 406{
 407	struct nilfs_segment_usage *su;
 408	void *kaddr;
 409
 410	kaddr = kmap_atomic(su_bh->b_page);
 411	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 412	if (unlikely(!nilfs_segment_usage_clean(su))) {
 413		nilfs_msg(sufile->i_sb, KERN_WARNING,
 414			  "%s: segment %llu must be clean", __func__,
 415			  (unsigned long long)segnum);
 416		kunmap_atomic(kaddr);
 417		return;
 418	}
 419	nilfs_segment_usage_set_dirty(su);
 420	kunmap_atomic(kaddr);
 421
 422	nilfs_sufile_mod_counter(header_bh, -1, 1);
 423	NILFS_SUI(sufile)->ncleansegs--;
 424
 425	mark_buffer_dirty(su_bh);
 426	nilfs_mdt_mark_dirty(sufile);
 427}
 428
 429void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 430			   struct buffer_head *header_bh,
 431			   struct buffer_head *su_bh)
 432{
 433	struct nilfs_segment_usage *su;
 434	void *kaddr;
 435	int clean, dirty;
 436
 437	kaddr = kmap_atomic(su_bh->b_page);
 438	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 439	if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
 440	    su->su_nblocks == cpu_to_le32(0)) {
 441		kunmap_atomic(kaddr);
 442		return;
 443	}
 444	clean = nilfs_segment_usage_clean(su);
 445	dirty = nilfs_segment_usage_dirty(su);
 446
 447	/* make the segment garbage */
 448	su->su_lastmod = cpu_to_le64(0);
 449	su->su_nblocks = cpu_to_le32(0);
 450	su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
 451	kunmap_atomic(kaddr);
 452
 453	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 454	NILFS_SUI(sufile)->ncleansegs -= clean;
 455
 456	mark_buffer_dirty(su_bh);
 457	nilfs_mdt_mark_dirty(sufile);
 458}
 459
 460void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 461			  struct buffer_head *header_bh,
 462			  struct buffer_head *su_bh)
 463{
 464	struct nilfs_segment_usage *su;
 465	void *kaddr;
 466	int sudirty;
 467
 468	kaddr = kmap_atomic(su_bh->b_page);
 469	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 470	if (nilfs_segment_usage_clean(su)) {
 471		nilfs_msg(sufile->i_sb, KERN_WARNING,
 472			  "%s: segment %llu is already clean",
 473			  __func__, (unsigned long long)segnum);
 474		kunmap_atomic(kaddr);
 475		return;
 476	}
 477	WARN_ON(nilfs_segment_usage_error(su));
 478	WARN_ON(!nilfs_segment_usage_dirty(su));
 479
 480	sudirty = nilfs_segment_usage_dirty(su);
 481	nilfs_segment_usage_set_clean(su);
 482	kunmap_atomic(kaddr);
 483	mark_buffer_dirty(su_bh);
 484
 485	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 486	NILFS_SUI(sufile)->ncleansegs++;
 487
 488	nilfs_mdt_mark_dirty(sufile);
 489
 490	trace_nilfs2_segment_usage_freed(sufile, segnum);
 491}
 492
 493/**
 494 * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 495 * @sufile: inode of segment usage file
 496 * @segnum: segment number
 497 */
 498int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 499{
 500	struct buffer_head *bh;
 501	int ret;
 502
 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		brelse(bh);
 508	}
 509	return ret;
 510}
 511
 512/**
 513 * nilfs_sufile_set_segment_usage - set usage of a segment
 514 * @sufile: inode of segment usage file
 515 * @segnum: segment number
 516 * @nblocks: number of live blocks in the segment
 517 * @modtime: modification time (option)
 518 */
 519int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 520				   unsigned long nblocks, time64_t modtime)
 521{
 522	struct buffer_head *bh;
 523	struct nilfs_segment_usage *su;
 524	void *kaddr;
 525	int ret;
 526
 527	down_write(&NILFS_MDT(sufile)->mi_sem);
 528	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 529	if (ret < 0)
 530		goto out_sem;
 531
 532	kaddr = kmap_atomic(bh->b_page);
 533	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 534	WARN_ON(nilfs_segment_usage_error(su));
 535	if (modtime)
 536		su->su_lastmod = cpu_to_le64(modtime);
 537	su->su_nblocks = cpu_to_le32(nblocks);
 538	kunmap_atomic(kaddr);
 539
 540	mark_buffer_dirty(bh);
 541	nilfs_mdt_mark_dirty(sufile);
 542	brelse(bh);
 543
 544 out_sem:
 545	up_write(&NILFS_MDT(sufile)->mi_sem);
 546	return ret;
 547}
 548
 549/**
 550 * nilfs_sufile_get_stat - get segment usage statistics
 551 * @sufile: inode of segment usage file
 552 * @stat: pointer to a structure of segment usage statistics
 553 *
 554 * Description: nilfs_sufile_get_stat() returns information about segment
 555 * usage.
 556 *
 557 * Return Value: On success, 0 is returned, and segment usage information is
 558 * stored in the place pointed by @stat. On error, one of the following
 559 * negative error codes is returned.
 560 *
 561 * %-EIO - I/O error.
 562 *
 563 * %-ENOMEM - Insufficient amount of memory available.
 564 */
 565int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 566{
 567	struct buffer_head *header_bh;
 568	struct nilfs_sufile_header *header;
 569	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 570	void *kaddr;
 571	int ret;
 572
 573	down_read(&NILFS_MDT(sufile)->mi_sem);
 574
 575	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 576	if (ret < 0)
 577		goto out_sem;
 578
 579	kaddr = kmap_atomic(header_bh->b_page);
 580	header = kaddr + bh_offset(header_bh);
 581	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 582	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 583	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 584	sustat->ss_ctime = nilfs->ns_ctime;
 585	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 586	spin_lock(&nilfs->ns_last_segment_lock);
 587	sustat->ss_prot_seq = nilfs->ns_prot_seq;
 588	spin_unlock(&nilfs->ns_last_segment_lock);
 589	kunmap_atomic(kaddr);
 590	brelse(header_bh);
 591
 592 out_sem:
 593	up_read(&NILFS_MDT(sufile)->mi_sem);
 594	return ret;
 595}
 596
 597void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 598			       struct buffer_head *header_bh,
 599			       struct buffer_head *su_bh)
 600{
 601	struct nilfs_segment_usage *su;
 602	void *kaddr;
 603	int suclean;
 604
 605	kaddr = kmap_atomic(su_bh->b_page);
 606	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 607	if (nilfs_segment_usage_error(su)) {
 608		kunmap_atomic(kaddr);
 609		return;
 610	}
 611	suclean = nilfs_segment_usage_clean(su);
 612	nilfs_segment_usage_set_error(su);
 613	kunmap_atomic(kaddr);
 614
 615	if (suclean) {
 616		nilfs_sufile_mod_counter(header_bh, -1, 0);
 617		NILFS_SUI(sufile)->ncleansegs--;
 618	}
 619	mark_buffer_dirty(su_bh);
 620	nilfs_mdt_mark_dirty(sufile);
 621}
 622
 623/**
 624 * nilfs_sufile_truncate_range - truncate range of segment array
 625 * @sufile: inode of segment usage file
 626 * @start: start segment number (inclusive)
 627 * @end: end segment number (inclusive)
 628 *
 629 * Return Value: On success, 0 is returned.  On error, one of the
 630 * following negative error codes is returned.
 631 *
 632 * %-EIO - I/O error.
 633 *
 634 * %-ENOMEM - Insufficient amount of memory available.
 635 *
 636 * %-EINVAL - Invalid number of segments specified
 637 *
 638 * %-EBUSY - Dirty or active segments are present in the range
 639 */
 640static int nilfs_sufile_truncate_range(struct inode *sufile,
 641				       __u64 start, __u64 end)
 642{
 643	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 644	struct buffer_head *header_bh;
 645	struct buffer_head *su_bh;
 646	struct nilfs_segment_usage *su, *su2;
 647	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 648	unsigned long segusages_per_block;
 649	unsigned long nsegs, ncleaned;
 650	__u64 segnum;
 651	void *kaddr;
 652	ssize_t n, nc;
 653	int ret;
 654	int j;
 655
 656	nsegs = nilfs_sufile_get_nsegments(sufile);
 657
 658	ret = -EINVAL;
 659	if (start > end || start >= nsegs)
 660		goto out;
 661
 662	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 663	if (ret < 0)
 664		goto out;
 665
 666	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 667	ncleaned = 0;
 668
 669	for (segnum = start; segnum <= end; segnum += n) {
 670		n = min_t(unsigned long,
 671			  segusages_per_block -
 672				  nilfs_sufile_get_offset(sufile, segnum),
 673			  end - segnum + 1);
 674		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 675							   &su_bh);
 676		if (ret < 0) {
 677			if (ret != -ENOENT)
 678				goto out_header;
 679			/* hole */
 680			continue;
 681		}
 682		kaddr = kmap_atomic(su_bh->b_page);
 683		su = nilfs_sufile_block_get_segment_usage(
 684			sufile, segnum, su_bh, kaddr);
 685		su2 = su;
 686		for (j = 0; j < n; j++, su = (void *)su + susz) {
 687			if ((le32_to_cpu(su->su_flags) &
 688			     ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
 689			    nilfs_segment_is_active(nilfs, segnum + j)) {
 690				ret = -EBUSY;
 691				kunmap_atomic(kaddr);
 692				brelse(su_bh);
 693				goto out_header;
 694			}
 695		}
 696		nc = 0;
 697		for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 698			if (nilfs_segment_usage_error(su)) {
 699				nilfs_segment_usage_set_clean(su);
 700				nc++;
 701			}
 702		}
 703		kunmap_atomic(kaddr);
 704		if (nc > 0) {
 705			mark_buffer_dirty(su_bh);
 706			ncleaned += nc;
 707		}
 708		brelse(su_bh);
 709
 710		if (n == segusages_per_block) {
 711			/* make hole */
 712			nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 713		}
 714	}
 715	ret = 0;
 716
 717out_header:
 718	if (ncleaned > 0) {
 719		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 720		nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 721		nilfs_mdt_mark_dirty(sufile);
 722	}
 723	brelse(header_bh);
 724out:
 725	return ret;
 726}
 727
 728/**
 729 * nilfs_sufile_resize - resize segment array
 730 * @sufile: inode of segment usage file
 731 * @newnsegs: new number of segments
 732 *
 733 * Return Value: On success, 0 is returned.  On error, one of the
 734 * following negative error codes is returned.
 735 *
 736 * %-EIO - I/O error.
 737 *
 738 * %-ENOMEM - Insufficient amount of memory available.
 739 *
 740 * %-ENOSPC - Enough free space is not left for shrinking
 741 *
 742 * %-EBUSY - Dirty or active segments exist in the region to be truncated
 743 */
 744int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 745{
 746	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 747	struct buffer_head *header_bh;
 748	struct nilfs_sufile_header *header;
 749	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 750	void *kaddr;
 751	unsigned long nsegs, nrsvsegs;
 752	int ret = 0;
 753
 754	down_write(&NILFS_MDT(sufile)->mi_sem);
 755
 756	nsegs = nilfs_sufile_get_nsegments(sufile);
 757	if (nsegs == newnsegs)
 758		goto out;
 759
 760	ret = -ENOSPC;
 761	nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 762	if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 763		goto out;
 764
 765	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 766	if (ret < 0)
 767		goto out;
 768
 769	if (newnsegs > nsegs) {
 770		sui->ncleansegs += newnsegs - nsegs;
 771	} else /* newnsegs < nsegs */ {
 772		ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 773		if (ret < 0)
 774			goto out_header;
 775
 776		sui->ncleansegs -= nsegs - newnsegs;
 777	}
 778
 779	kaddr = kmap_atomic(header_bh->b_page);
 780	header = kaddr + bh_offset(header_bh);
 781	header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 782	kunmap_atomic(kaddr);
 783
 784	mark_buffer_dirty(header_bh);
 785	nilfs_mdt_mark_dirty(sufile);
 786	nilfs_set_nsegments(nilfs, newnsegs);
 787
 788out_header:
 789	brelse(header_bh);
 790out:
 791	up_write(&NILFS_MDT(sufile)->mi_sem);
 792	return ret;
 793}
 794
 795/**
 796 * nilfs_sufile_get_suinfo -
 797 * @sufile: inode of segment usage file
 798 * @segnum: segment number to start looking
 799 * @buf: array of suinfo
 800 * @sisz: byte size of suinfo
 801 * @nsi: size of suinfo array
 802 *
 803 * Description:
 804 *
 805 * Return Value: On success, 0 is returned and .... On error, one of the
 806 * following negative error codes is returned.
 807 *
 808 * %-EIO - I/O error.
 809 *
 810 * %-ENOMEM - Insufficient amount of memory available.
 811 */
 812ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 813				unsigned int sisz, size_t nsi)
 814{
 815	struct buffer_head *su_bh;
 816	struct nilfs_segment_usage *su;
 817	struct nilfs_suinfo *si = buf;
 818	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 819	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 820	void *kaddr;
 821	unsigned long nsegs, segusages_per_block;
 822	ssize_t n;
 823	int ret, i, j;
 824
 825	down_read(&NILFS_MDT(sufile)->mi_sem);
 826
 827	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 828	nsegs = min_t(unsigned long,
 829		      nilfs_sufile_get_nsegments(sufile) - segnum,
 830		      nsi);
 831	for (i = 0; i < nsegs; i += n, segnum += n) {
 832		n = min_t(unsigned long,
 833			  segusages_per_block -
 834				  nilfs_sufile_get_offset(sufile, segnum),
 835			  nsegs - i);
 836		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 837							   &su_bh);
 838		if (ret < 0) {
 839			if (ret != -ENOENT)
 840				goto out;
 841			/* hole */
 842			memset(si, 0, sisz * n);
 843			si = (void *)si + sisz * n;
 844			continue;
 845		}
 846
 847		kaddr = kmap_atomic(su_bh->b_page);
 848		su = nilfs_sufile_block_get_segment_usage(
 849			sufile, segnum, su_bh, kaddr);
 850		for (j = 0; j < n;
 851		     j++, su = (void *)su + susz, si = (void *)si + sisz) {
 852			si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 853			si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 854			si->sui_flags = le32_to_cpu(su->su_flags) &
 855				~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 856			if (nilfs_segment_is_active(nilfs, segnum + j))
 857				si->sui_flags |=
 858					BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 859		}
 860		kunmap_atomic(kaddr);
 861		brelse(su_bh);
 862	}
 863	ret = nsegs;
 864
 865 out:
 866	up_read(&NILFS_MDT(sufile)->mi_sem);
 867	return ret;
 868}
 869
 870/**
 871 * nilfs_sufile_set_suinfo - sets segment usage info
 872 * @sufile: inode of segment usage file
 873 * @buf: array of suinfo_update
 874 * @supsz: byte size of suinfo_update
 875 * @nsup: size of suinfo_update array
 876 *
 877 * Description: Takes an array of nilfs_suinfo_update structs and updates
 878 * segment usage accordingly. Only the fields indicated by the sup_flags
 879 * are updated.
 880 *
 881 * Return Value: On success, 0 is returned. On error, one of the
 882 * following negative error codes is returned.
 883 *
 884 * %-EIO - I/O error.
 885 *
 886 * %-ENOMEM - Insufficient amount of memory available.
 887 *
 888 * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 889 */
 890ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 891				unsigned int supsz, size_t nsup)
 892{
 893	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 894	struct buffer_head *header_bh, *bh;
 895	struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 896	struct nilfs_segment_usage *su;
 897	void *kaddr;
 898	unsigned long blkoff, prev_blkoff;
 899	int cleansi, cleansu, dirtysi, dirtysu;
 900	long ncleaned = 0, ndirtied = 0;
 901	int ret = 0;
 902
 903	if (unlikely(nsup == 0))
 904		return ret;
 905
 906	for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 907		if (sup->sup_segnum >= nilfs->ns_nsegments
 908			|| (sup->sup_flags &
 909				(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 910			|| (nilfs_suinfo_update_nblocks(sup) &&
 911				sup->sup_sui.sui_nblocks >
 912				nilfs->ns_blocks_per_segment))
 913			return -EINVAL;
 914	}
 915
 916	down_write(&NILFS_MDT(sufile)->mi_sem);
 917
 918	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 919	if (ret < 0)
 920		goto out_sem;
 921
 922	sup = buf;
 923	blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 924	ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 925	if (ret < 0)
 926		goto out_header;
 927
 928	for (;;) {
 929		kaddr = kmap_atomic(bh->b_page);
 930		su = nilfs_sufile_block_get_segment_usage(
 931			sufile, sup->sup_segnum, bh, kaddr);
 932
 933		if (nilfs_suinfo_update_lastmod(sup))
 934			su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 935
 936		if (nilfs_suinfo_update_nblocks(sup))
 937			su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 938
 939		if (nilfs_suinfo_update_flags(sup)) {
 940			/*
 941			 * Active flag is a virtual flag projected by running
 942			 * nilfs kernel code - drop it not to write it to
 943			 * disk.
 944			 */
 945			sup->sup_sui.sui_flags &=
 946					~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 947
 948			cleansi = nilfs_suinfo_clean(&sup->sup_sui);
 949			cleansu = nilfs_segment_usage_clean(su);
 950			dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
 951			dirtysu = nilfs_segment_usage_dirty(su);
 952
 953			if (cleansi && !cleansu)
 954				++ncleaned;
 955			else if (!cleansi && cleansu)
 956				--ncleaned;
 957
 958			if (dirtysi && !dirtysu)
 959				++ndirtied;
 960			else if (!dirtysi && dirtysu)
 961				--ndirtied;
 962
 963			su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
 964		}
 965
 966		kunmap_atomic(kaddr);
 967
 968		sup = (void *)sup + supsz;
 969		if (sup >= supend)
 970			break;
 971
 972		prev_blkoff = blkoff;
 973		blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 974		if (blkoff == prev_blkoff)
 975			continue;
 976
 977		/* get different block */
 978		mark_buffer_dirty(bh);
 979		put_bh(bh);
 980		ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 981		if (unlikely(ret < 0))
 982			goto out_mark;
 983	}
 984	mark_buffer_dirty(bh);
 985	put_bh(bh);
 986
 987 out_mark:
 988	if (ncleaned || ndirtied) {
 989		nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
 990				(u64)ndirtied);
 991		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 992	}
 993	nilfs_mdt_mark_dirty(sufile);
 994 out_header:
 995	put_bh(header_bh);
 996 out_sem:
 997	up_write(&NILFS_MDT(sufile)->mi_sem);
 998	return ret;
 999}
1000
1001/**
1002 * nilfs_sufile_trim_fs() - trim ioctl handle function
1003 * @sufile: inode of segment usage file
1004 * @range: fstrim_range structure
1005 *
1006 * start:	First Byte to trim
1007 * len:		number of Bytes to trim from start
1008 * minlen:	minimum extent length in Bytes
1009 *
1010 * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1011 * from start to start+len. start is rounded up to the next block boundary
1012 * and start+len is rounded down. For each clean segment blkdev_issue_discard
1013 * function is invoked.
1014 *
1015 * Return Value: On success, 0 is returned or negative error code, otherwise.
1016 */
1017int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1018{
1019	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1020	struct buffer_head *su_bh;
1021	struct nilfs_segment_usage *su;
1022	void *kaddr;
1023	size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1024	sector_t seg_start, seg_end, start_block, end_block;
1025	sector_t start = 0, nblocks = 0;
1026	u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1027	int ret = 0;
1028	unsigned int sects_per_block;
1029
1030	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1031			bdev_logical_block_size(nilfs->ns_bdev);
1032	len = range->len >> nilfs->ns_blocksize_bits;
1033	minlen = range->minlen >> nilfs->ns_blocksize_bits;
1034	max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1035
1036	if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1037		return -EINVAL;
1038
1039	start_block = (range->start + nilfs->ns_blocksize - 1) >>
1040			nilfs->ns_blocksize_bits;
1041
1042	/*
1043	 * range->len can be very large (actually, it is set to
1044	 * ULLONG_MAX by default) - truncate upper end of the range
1045	 * carefully so as not to overflow.
1046	 */
1047	if (max_blocks - start_block < len)
1048		end_block = max_blocks - 1;
1049	else
1050		end_block = start_block + len - 1;
1051
1052	segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1053	segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1054
1055	down_read(&NILFS_MDT(sufile)->mi_sem);
1056
1057	while (segnum <= segnum_end) {
1058		n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1059				segnum_end);
1060
1061		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1062							   &su_bh);
1063		if (ret < 0) {
1064			if (ret != -ENOENT)
1065				goto out_sem;
1066			/* hole */
1067			segnum += n;
1068			continue;
1069		}
1070
1071		kaddr = kmap_atomic(su_bh->b_page);
1072		su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1073				su_bh, kaddr);
1074		for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1075			if (!nilfs_segment_usage_clean(su))
1076				continue;
1077
1078			nilfs_get_segment_range(nilfs, segnum, &seg_start,
1079						&seg_end);
1080
1081			if (!nblocks) {
1082				/* start new extent */
1083				start = seg_start;
1084				nblocks = seg_end - seg_start + 1;
1085				continue;
1086			}
1087
1088			if (start + nblocks == seg_start) {
1089				/* add to previous extent */
1090				nblocks += seg_end - seg_start + 1;
1091				continue;
1092			}
1093
1094			/* discard previous extent */
1095			if (start < start_block) {
1096				nblocks -= start_block - start;
1097				start = start_block;
1098			}
1099
1100			if (nblocks >= minlen) {
1101				kunmap_atomic(kaddr);
1102
1103				ret = blkdev_issue_discard(nilfs->ns_bdev,
1104						start * sects_per_block,
1105						nblocks * sects_per_block,
1106						GFP_NOFS, 0);
1107				if (ret < 0) {
1108					put_bh(su_bh);
1109					goto out_sem;
1110				}
1111
1112				ndiscarded += nblocks;
1113				kaddr = kmap_atomic(su_bh->b_page);
1114				su = nilfs_sufile_block_get_segment_usage(
1115					sufile, segnum, su_bh, kaddr);
1116			}
1117
1118			/* start new extent */
1119			start = seg_start;
1120			nblocks = seg_end - seg_start + 1;
1121		}
1122		kunmap_atomic(kaddr);
1123		put_bh(su_bh);
1124	}
1125
1126
1127	if (nblocks) {
1128		/* discard last extent */
1129		if (start < start_block) {
1130			nblocks -= start_block - start;
1131			start = start_block;
1132		}
1133		if (start + nblocks > end_block + 1)
1134			nblocks = end_block - start + 1;
1135
1136		if (nblocks >= minlen) {
1137			ret = blkdev_issue_discard(nilfs->ns_bdev,
1138					start * sects_per_block,
1139					nblocks * sects_per_block,
1140					GFP_NOFS, 0);
1141			if (!ret)
1142				ndiscarded += nblocks;
1143		}
1144	}
1145
1146out_sem:
1147	up_read(&NILFS_MDT(sufile)->mi_sem);
1148
1149	range->len = ndiscarded << nilfs->ns_blocksize_bits;
1150	return ret;
1151}
1152
1153/**
1154 * nilfs_sufile_read - read or get sufile inode
1155 * @sb: super block instance
1156 * @susize: size of a segment usage entry
1157 * @raw_inode: on-disk sufile inode
1158 * @inodep: buffer to store the inode
1159 */
1160int nilfs_sufile_read(struct super_block *sb, size_t susize,
1161		      struct nilfs_inode *raw_inode, struct inode **inodep)
1162{
1163	struct inode *sufile;
1164	struct nilfs_sufile_info *sui;
1165	struct buffer_head *header_bh;
1166	struct nilfs_sufile_header *header;
1167	void *kaddr;
1168	int err;
1169
1170	if (susize > sb->s_blocksize) {
1171		nilfs_msg(sb, KERN_ERR,
1172			  "too large segment usage size: %zu bytes", susize);
1173		return -EINVAL;
1174	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1175		nilfs_msg(sb, KERN_ERR,
1176			  "too small segment usage size: %zu bytes", susize);
1177		return -EINVAL;
1178	}
1179
1180	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1181	if (unlikely(!sufile))
1182		return -ENOMEM;
1183	if (!(sufile->i_state & I_NEW))
1184		goto out;
1185
1186	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1187	if (err)
1188		goto failed;
1189
1190	nilfs_mdt_set_entry_size(sufile, susize,
1191				 sizeof(struct nilfs_sufile_header));
1192
1193	err = nilfs_read_inode_common(sufile, raw_inode);
1194	if (err)
1195		goto failed;
1196
1197	err = nilfs_sufile_get_header_block(sufile, &header_bh);
1198	if (err)
1199		goto failed;
1200
1201	sui = NILFS_SUI(sufile);
1202	kaddr = kmap_atomic(header_bh->b_page);
1203	header = kaddr + bh_offset(header_bh);
1204	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1205	kunmap_atomic(kaddr);
1206	brelse(header_bh);
1207
1208	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1209	sui->allocmin = 0;
1210
1211	unlock_new_inode(sufile);
1212 out:
1213	*inodep = sufile;
1214	return 0;
1215 failed:
1216	iget_failed(sufile);
1217	return err;
1218}