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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}
v6.8
   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	if (unlikely(nilfs_segment_usage_error(su)))
 475		nilfs_warn(sufile->i_sb, "free segment %llu marked in error",
 476			   (unsigned long long)segnum);
 477
 478	sudirty = nilfs_segment_usage_dirty(su);
 479	if (unlikely(!sudirty))
 480		nilfs_warn(sufile->i_sb, "free unallocated segment %llu",
 481			   (unsigned long long)segnum);
 482
 483	nilfs_segment_usage_set_clean(su);
 484	kunmap_atomic(kaddr);
 485	mark_buffer_dirty(su_bh);
 486
 487	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 488	NILFS_SUI(sufile)->ncleansegs++;
 489
 490	nilfs_mdt_mark_dirty(sufile);
 491
 492	trace_nilfs2_segment_usage_freed(sufile, segnum);
 493}
 494
 495/**
 496 * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 497 * @sufile: inode of segment usage file
 498 * @segnum: segment number
 499 */
 500int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 501{
 502	struct buffer_head *bh;
 503	void *kaddr;
 504	struct nilfs_segment_usage *su;
 505	int ret;
 506
 507	down_write(&NILFS_MDT(sufile)->mi_sem);
 508	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 509	if (ret)
 510		goto out_sem;
 511
 512	kaddr = kmap_atomic(bh->b_page);
 513	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 514	if (unlikely(nilfs_segment_usage_error(su))) {
 515		struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 516
 517		kunmap_atomic(kaddr);
 518		brelse(bh);
 519		if (nilfs_segment_is_active(nilfs, segnum)) {
 520			nilfs_error(sufile->i_sb,
 521				    "active segment %llu is erroneous",
 522				    (unsigned long long)segnum);
 523		} else {
 524			/*
 525			 * Segments marked erroneous are never allocated by
 526			 * nilfs_sufile_alloc(); only active segments, ie,
 527			 * the segments indexed by ns_segnum or ns_nextnum,
 528			 * can be erroneous here.
 529			 */
 530			WARN_ON_ONCE(1);
 531		}
 532		ret = -EIO;
 533	} else {
 534		nilfs_segment_usage_set_dirty(su);
 535		kunmap_atomic(kaddr);
 536		mark_buffer_dirty(bh);
 537		nilfs_mdt_mark_dirty(sufile);
 538		brelse(bh);
 539	}
 540out_sem:
 541	up_write(&NILFS_MDT(sufile)->mi_sem);
 542	return ret;
 543}
 544
 545/**
 546 * nilfs_sufile_set_segment_usage - set usage of a segment
 547 * @sufile: inode of segment usage file
 548 * @segnum: segment number
 549 * @nblocks: number of live blocks in the segment
 550 * @modtime: modification time (option)
 551 */
 552int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 553				   unsigned long nblocks, time64_t modtime)
 554{
 555	struct buffer_head *bh;
 556	struct nilfs_segment_usage *su;
 557	void *kaddr;
 558	int ret;
 559
 560	down_write(&NILFS_MDT(sufile)->mi_sem);
 561	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 562	if (ret < 0)
 563		goto out_sem;
 564
 565	kaddr = kmap_atomic(bh->b_page);
 566	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
 567	if (modtime) {
 568		/*
 569		 * Check segusage error and set su_lastmod only when updating
 570		 * this entry with a valid timestamp, not for cancellation.
 571		 */
 572		WARN_ON_ONCE(nilfs_segment_usage_error(su));
 573		su->su_lastmod = cpu_to_le64(modtime);
 574	}
 575	su->su_nblocks = cpu_to_le32(nblocks);
 576	kunmap_atomic(kaddr);
 577
 578	mark_buffer_dirty(bh);
 579	nilfs_mdt_mark_dirty(sufile);
 580	brelse(bh);
 581
 582 out_sem:
 583	up_write(&NILFS_MDT(sufile)->mi_sem);
 584	return ret;
 585}
 586
 587/**
 588 * nilfs_sufile_get_stat - get segment usage statistics
 589 * @sufile: inode of segment usage file
 590 * @sustat: pointer to a structure of segment usage statistics
 591 *
 592 * Description: nilfs_sufile_get_stat() returns information about segment
 593 * usage.
 594 *
 595 * Return Value: On success, 0 is returned, and segment usage information is
 596 * stored in the place pointed by @sustat. On error, one of the following
 597 * negative error codes is returned.
 598 *
 599 * %-EIO - I/O error.
 600 *
 601 * %-ENOMEM - Insufficient amount of memory available.
 602 */
 603int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 604{
 605	struct buffer_head *header_bh;
 606	struct nilfs_sufile_header *header;
 607	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 608	void *kaddr;
 609	int ret;
 610
 611	down_read(&NILFS_MDT(sufile)->mi_sem);
 612
 613	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 614	if (ret < 0)
 615		goto out_sem;
 616
 617	kaddr = kmap_atomic(header_bh->b_page);
 618	header = kaddr + bh_offset(header_bh);
 619	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 620	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 621	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 622	sustat->ss_ctime = nilfs->ns_ctime;
 623	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 624	spin_lock(&nilfs->ns_last_segment_lock);
 625	sustat->ss_prot_seq = nilfs->ns_prot_seq;
 626	spin_unlock(&nilfs->ns_last_segment_lock);
 627	kunmap_atomic(kaddr);
 628	brelse(header_bh);
 629
 630 out_sem:
 631	up_read(&NILFS_MDT(sufile)->mi_sem);
 632	return ret;
 633}
 634
 635void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 636			       struct buffer_head *header_bh,
 637			       struct buffer_head *su_bh)
 638{
 639	struct nilfs_segment_usage *su;
 640	void *kaddr;
 641	int suclean;
 642
 643	kaddr = kmap_atomic(su_bh->b_page);
 644	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 645	if (nilfs_segment_usage_error(su)) {
 646		kunmap_atomic(kaddr);
 647		return;
 648	}
 649	suclean = nilfs_segment_usage_clean(su);
 650	nilfs_segment_usage_set_error(su);
 651	kunmap_atomic(kaddr);
 652
 653	if (suclean) {
 654		nilfs_sufile_mod_counter(header_bh, -1, 0);
 655		NILFS_SUI(sufile)->ncleansegs--;
 656	}
 657	mark_buffer_dirty(su_bh);
 658	nilfs_mdt_mark_dirty(sufile);
 659}
 660
 661/**
 662 * nilfs_sufile_truncate_range - truncate range of segment array
 663 * @sufile: inode of segment usage file
 664 * @start: start segment number (inclusive)
 665 * @end: end segment number (inclusive)
 666 *
 667 * Return Value: On success, 0 is returned.  On error, one of the
 668 * following negative error codes is returned.
 669 *
 670 * %-EIO - I/O error.
 671 *
 672 * %-ENOMEM - Insufficient amount of memory available.
 673 *
 674 * %-EINVAL - Invalid number of segments specified
 675 *
 676 * %-EBUSY - Dirty or active segments are present in the range
 677 */
 678static int nilfs_sufile_truncate_range(struct inode *sufile,
 679				       __u64 start, __u64 end)
 680{
 681	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 682	struct buffer_head *header_bh;
 683	struct buffer_head *su_bh;
 684	struct nilfs_segment_usage *su, *su2;
 685	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 686	unsigned long segusages_per_block;
 687	unsigned long nsegs, ncleaned;
 688	__u64 segnum;
 689	void *kaddr;
 690	ssize_t n, nc;
 691	int ret;
 692	int j;
 693
 694	nsegs = nilfs_sufile_get_nsegments(sufile);
 695
 696	ret = -EINVAL;
 697	if (start > end || start >= nsegs)
 698		goto out;
 699
 700	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 701	if (ret < 0)
 702		goto out;
 703
 704	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 705	ncleaned = 0;
 706
 707	for (segnum = start; segnum <= end; segnum += n) {
 708		n = min_t(unsigned long,
 709			  segusages_per_block -
 710				  nilfs_sufile_get_offset(sufile, segnum),
 711			  end - segnum + 1);
 712		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 713							   &su_bh);
 714		if (ret < 0) {
 715			if (ret != -ENOENT)
 716				goto out_header;
 717			/* hole */
 718			continue;
 719		}
 720		kaddr = kmap_atomic(su_bh->b_page);
 721		su = nilfs_sufile_block_get_segment_usage(
 722			sufile, segnum, su_bh, kaddr);
 723		su2 = su;
 724		for (j = 0; j < n; j++, su = (void *)su + susz) {
 725			if ((le32_to_cpu(su->su_flags) &
 726			     ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
 727			    nilfs_segment_is_active(nilfs, segnum + j)) {
 728				ret = -EBUSY;
 729				kunmap_atomic(kaddr);
 730				brelse(su_bh);
 731				goto out_header;
 732			}
 733		}
 734		nc = 0;
 735		for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 736			if (nilfs_segment_usage_error(su)) {
 737				nilfs_segment_usage_set_clean(su);
 738				nc++;
 739			}
 740		}
 741		kunmap_atomic(kaddr);
 742		if (nc > 0) {
 743			mark_buffer_dirty(su_bh);
 744			ncleaned += nc;
 745		}
 746		brelse(su_bh);
 747
 748		if (n == segusages_per_block) {
 749			/* make hole */
 750			nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 751		}
 752	}
 753	ret = 0;
 754
 755out_header:
 756	if (ncleaned > 0) {
 757		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 758		nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 759		nilfs_mdt_mark_dirty(sufile);
 760	}
 761	brelse(header_bh);
 762out:
 763	return ret;
 764}
 765
 766/**
 767 * nilfs_sufile_resize - resize segment array
 768 * @sufile: inode of segment usage file
 769 * @newnsegs: new number of segments
 770 *
 771 * Return Value: On success, 0 is returned.  On error, one of the
 772 * following negative error codes is returned.
 773 *
 774 * %-EIO - I/O error.
 775 *
 776 * %-ENOMEM - Insufficient amount of memory available.
 777 *
 778 * %-ENOSPC - Enough free space is not left for shrinking
 779 *
 780 * %-EBUSY - Dirty or active segments exist in the region to be truncated
 781 */
 782int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 783{
 784	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 785	struct buffer_head *header_bh;
 786	struct nilfs_sufile_header *header;
 787	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 788	void *kaddr;
 789	unsigned long nsegs, nrsvsegs;
 790	int ret = 0;
 791
 792	down_write(&NILFS_MDT(sufile)->mi_sem);
 793
 794	nsegs = nilfs_sufile_get_nsegments(sufile);
 795	if (nsegs == newnsegs)
 796		goto out;
 797
 798	ret = -ENOSPC;
 799	nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 800	if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 801		goto out;
 802
 803	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 804	if (ret < 0)
 805		goto out;
 806
 807	if (newnsegs > nsegs) {
 808		sui->ncleansegs += newnsegs - nsegs;
 809	} else /* newnsegs < nsegs */ {
 810		ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 811		if (ret < 0)
 812			goto out_header;
 813
 814		sui->ncleansegs -= nsegs - newnsegs;
 815
 816		/*
 817		 * If the sufile is successfully truncated, immediately adjust
 818		 * the segment allocation space while locking the semaphore
 819		 * "mi_sem" so that nilfs_sufile_alloc() never allocates
 820		 * segments in the truncated space.
 821		 */
 822		sui->allocmax = newnsegs - 1;
 823		sui->allocmin = 0;
 824	}
 825
 826	kaddr = kmap_atomic(header_bh->b_page);
 827	header = kaddr + bh_offset(header_bh);
 828	header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 829	kunmap_atomic(kaddr);
 830
 831	mark_buffer_dirty(header_bh);
 832	nilfs_mdt_mark_dirty(sufile);
 833	nilfs_set_nsegments(nilfs, newnsegs);
 834
 835out_header:
 836	brelse(header_bh);
 837out:
 838	up_write(&NILFS_MDT(sufile)->mi_sem);
 839	return ret;
 840}
 841
 842/**
 843 * nilfs_sufile_get_suinfo -
 844 * @sufile: inode of segment usage file
 845 * @segnum: segment number to start looking
 846 * @buf: array of suinfo
 847 * @sisz: byte size of suinfo
 848 * @nsi: size of suinfo array
 849 *
 850 * Description:
 851 *
 852 * Return Value: On success, 0 is returned and .... On error, one of the
 853 * following negative error codes is returned.
 854 *
 855 * %-EIO - I/O error.
 856 *
 857 * %-ENOMEM - Insufficient amount of memory available.
 858 */
 859ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 860				unsigned int sisz, size_t nsi)
 861{
 862	struct buffer_head *su_bh;
 863	struct nilfs_segment_usage *su;
 864	struct nilfs_suinfo *si = buf;
 865	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 866	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 867	void *kaddr;
 868	unsigned long nsegs, segusages_per_block;
 869	ssize_t n;
 870	int ret, i, j;
 871
 872	down_read(&NILFS_MDT(sufile)->mi_sem);
 873
 874	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 875	nsegs = min_t(unsigned long,
 876		      nilfs_sufile_get_nsegments(sufile) - segnum,
 877		      nsi);
 878	for (i = 0; i < nsegs; i += n, segnum += n) {
 879		n = min_t(unsigned long,
 880			  segusages_per_block -
 881				  nilfs_sufile_get_offset(sufile, segnum),
 882			  nsegs - i);
 883		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 884							   &su_bh);
 885		if (ret < 0) {
 886			if (ret != -ENOENT)
 887				goto out;
 888			/* hole */
 889			memset(si, 0, sisz * n);
 890			si = (void *)si + sisz * n;
 891			continue;
 892		}
 893
 894		kaddr = kmap_atomic(su_bh->b_page);
 895		su = nilfs_sufile_block_get_segment_usage(
 896			sufile, segnum, su_bh, kaddr);
 897		for (j = 0; j < n;
 898		     j++, su = (void *)su + susz, si = (void *)si + sisz) {
 899			si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 900			si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 901			si->sui_flags = le32_to_cpu(su->su_flags) &
 902				~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 903			if (nilfs_segment_is_active(nilfs, segnum + j))
 904				si->sui_flags |=
 905					BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 906		}
 907		kunmap_atomic(kaddr);
 908		brelse(su_bh);
 909	}
 910	ret = nsegs;
 911
 912 out:
 913	up_read(&NILFS_MDT(sufile)->mi_sem);
 914	return ret;
 915}
 916
 917/**
 918 * nilfs_sufile_set_suinfo - sets segment usage info
 919 * @sufile: inode of segment usage file
 920 * @buf: array of suinfo_update
 921 * @supsz: byte size of suinfo_update
 922 * @nsup: size of suinfo_update array
 923 *
 924 * Description: Takes an array of nilfs_suinfo_update structs and updates
 925 * segment usage accordingly. Only the fields indicated by the sup_flags
 926 * are updated.
 927 *
 928 * Return Value: On success, 0 is returned. On error, one of the
 929 * following negative error codes is returned.
 930 *
 931 * %-EIO - I/O error.
 932 *
 933 * %-ENOMEM - Insufficient amount of memory available.
 934 *
 935 * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 936 */
 937ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 938				unsigned int supsz, size_t nsup)
 939{
 940	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 941	struct buffer_head *header_bh, *bh;
 942	struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 943	struct nilfs_segment_usage *su;
 944	void *kaddr;
 945	unsigned long blkoff, prev_blkoff;
 946	int cleansi, cleansu, dirtysi, dirtysu;
 947	long ncleaned = 0, ndirtied = 0;
 948	int ret = 0;
 949
 950	if (unlikely(nsup == 0))
 951		return ret;
 952
 953	for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 954		if (sup->sup_segnum >= nilfs->ns_nsegments
 955			|| (sup->sup_flags &
 956				(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 957			|| (nilfs_suinfo_update_nblocks(sup) &&
 958				sup->sup_sui.sui_nblocks >
 959				nilfs->ns_blocks_per_segment))
 960			return -EINVAL;
 961	}
 962
 963	down_write(&NILFS_MDT(sufile)->mi_sem);
 964
 965	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 966	if (ret < 0)
 967		goto out_sem;
 968
 969	sup = buf;
 970	blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 971	ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 972	if (ret < 0)
 973		goto out_header;
 974
 975	for (;;) {
 976		kaddr = kmap_atomic(bh->b_page);
 977		su = nilfs_sufile_block_get_segment_usage(
 978			sufile, sup->sup_segnum, bh, kaddr);
 979
 980		if (nilfs_suinfo_update_lastmod(sup))
 981			su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 982
 983		if (nilfs_suinfo_update_nblocks(sup))
 984			su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 985
 986		if (nilfs_suinfo_update_flags(sup)) {
 987			/*
 988			 * Active flag is a virtual flag projected by running
 989			 * nilfs kernel code - drop it not to write it to
 990			 * disk.
 991			 */
 992			sup->sup_sui.sui_flags &=
 993					~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 994
 995			cleansi = nilfs_suinfo_clean(&sup->sup_sui);
 996			cleansu = nilfs_segment_usage_clean(su);
 997			dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
 998			dirtysu = nilfs_segment_usage_dirty(su);
 999
1000			if (cleansi && !cleansu)
1001				++ncleaned;
1002			else if (!cleansi && cleansu)
1003				--ncleaned;
1004
1005			if (dirtysi && !dirtysu)
1006				++ndirtied;
1007			else if (!dirtysi && dirtysu)
1008				--ndirtied;
1009
1010			su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
1011		}
1012
1013		kunmap_atomic(kaddr);
1014
1015		sup = (void *)sup + supsz;
1016		if (sup >= supend)
1017			break;
1018
1019		prev_blkoff = blkoff;
1020		blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
1021		if (blkoff == prev_blkoff)
1022			continue;
1023
1024		/* get different block */
1025		mark_buffer_dirty(bh);
1026		put_bh(bh);
1027		ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
1028		if (unlikely(ret < 0))
1029			goto out_mark;
1030	}
1031	mark_buffer_dirty(bh);
1032	put_bh(bh);
1033
1034 out_mark:
1035	if (ncleaned || ndirtied) {
1036		nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
1037				(u64)ndirtied);
1038		NILFS_SUI(sufile)->ncleansegs += ncleaned;
1039	}
1040	nilfs_mdt_mark_dirty(sufile);
1041 out_header:
1042	put_bh(header_bh);
1043 out_sem:
1044	up_write(&NILFS_MDT(sufile)->mi_sem);
1045	return ret;
1046}
1047
1048/**
1049 * nilfs_sufile_trim_fs() - trim ioctl handle function
1050 * @sufile: inode of segment usage file
1051 * @range: fstrim_range structure
1052 *
1053 * start:	First Byte to trim
1054 * len:		number of Bytes to trim from start
1055 * minlen:	minimum extent length in Bytes
1056 *
1057 * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1058 * from start to start+len. start is rounded up to the next block boundary
1059 * and start+len is rounded down. For each clean segment blkdev_issue_discard
1060 * function is invoked.
1061 *
1062 * Return Value: On success, 0 is returned or negative error code, otherwise.
1063 */
1064int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1065{
1066	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1067	struct buffer_head *su_bh;
1068	struct nilfs_segment_usage *su;
1069	void *kaddr;
1070	size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1071	sector_t seg_start, seg_end, start_block, end_block;
1072	sector_t start = 0, nblocks = 0;
1073	u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1074	int ret = 0;
1075	unsigned int sects_per_block;
1076
1077	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1078			bdev_logical_block_size(nilfs->ns_bdev);
1079	len = range->len >> nilfs->ns_blocksize_bits;
1080	minlen = range->minlen >> nilfs->ns_blocksize_bits;
1081	max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1082
1083	if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1084		return -EINVAL;
1085
1086	start_block = (range->start + nilfs->ns_blocksize - 1) >>
1087			nilfs->ns_blocksize_bits;
1088
1089	/*
1090	 * range->len can be very large (actually, it is set to
1091	 * ULLONG_MAX by default) - truncate upper end of the range
1092	 * carefully so as not to overflow.
1093	 */
1094	if (max_blocks - start_block < len)
1095		end_block = max_blocks - 1;
1096	else
1097		end_block = start_block + len - 1;
1098
1099	segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1100	segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1101
1102	down_read(&NILFS_MDT(sufile)->mi_sem);
1103
1104	while (segnum <= segnum_end) {
1105		n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1106				segnum_end);
1107
1108		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1109							   &su_bh);
1110		if (ret < 0) {
1111			if (ret != -ENOENT)
1112				goto out_sem;
1113			/* hole */
1114			segnum += n;
1115			continue;
1116		}
1117
1118		kaddr = kmap_atomic(su_bh->b_page);
1119		su = nilfs_sufile_block_get_segment_usage(sufile, segnum,
1120				su_bh, kaddr);
1121		for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1122			if (!nilfs_segment_usage_clean(su))
1123				continue;
1124
1125			nilfs_get_segment_range(nilfs, segnum, &seg_start,
1126						&seg_end);
1127
1128			if (!nblocks) {
1129				/* start new extent */
1130				start = seg_start;
1131				nblocks = seg_end - seg_start + 1;
1132				continue;
1133			}
1134
1135			if (start + nblocks == seg_start) {
1136				/* add to previous extent */
1137				nblocks += seg_end - seg_start + 1;
1138				continue;
1139			}
1140
1141			/* discard previous extent */
1142			if (start < start_block) {
1143				nblocks -= start_block - start;
1144				start = start_block;
1145			}
1146
1147			if (nblocks >= minlen) {
1148				kunmap_atomic(kaddr);
1149
1150				ret = blkdev_issue_discard(nilfs->ns_bdev,
1151						start * sects_per_block,
1152						nblocks * sects_per_block,
1153						GFP_NOFS);
1154				if (ret < 0) {
1155					put_bh(su_bh);
1156					goto out_sem;
1157				}
1158
1159				ndiscarded += nblocks;
1160				kaddr = kmap_atomic(su_bh->b_page);
1161				su = nilfs_sufile_block_get_segment_usage(
1162					sufile, segnum, su_bh, kaddr);
1163			}
1164
1165			/* start new extent */
1166			start = seg_start;
1167			nblocks = seg_end - seg_start + 1;
1168		}
1169		kunmap_atomic(kaddr);
1170		put_bh(su_bh);
1171	}
1172
1173
1174	if (nblocks) {
1175		/* discard last extent */
1176		if (start < start_block) {
1177			nblocks -= start_block - start;
1178			start = start_block;
1179		}
1180		if (start + nblocks > end_block + 1)
1181			nblocks = end_block - start + 1;
1182
1183		if (nblocks >= minlen) {
1184			ret = blkdev_issue_discard(nilfs->ns_bdev,
1185					start * sects_per_block,
1186					nblocks * sects_per_block,
1187					GFP_NOFS);
1188			if (!ret)
1189				ndiscarded += nblocks;
1190		}
1191	}
1192
1193out_sem:
1194	up_read(&NILFS_MDT(sufile)->mi_sem);
1195
1196	range->len = ndiscarded << nilfs->ns_blocksize_bits;
1197	return ret;
1198}
1199
1200/**
1201 * nilfs_sufile_read - read or get sufile inode
1202 * @sb: super block instance
1203 * @susize: size of a segment usage entry
1204 * @raw_inode: on-disk sufile inode
1205 * @inodep: buffer to store the inode
1206 */
1207int nilfs_sufile_read(struct super_block *sb, size_t susize,
1208		      struct nilfs_inode *raw_inode, struct inode **inodep)
1209{
1210	struct inode *sufile;
1211	struct nilfs_sufile_info *sui;
1212	struct buffer_head *header_bh;
1213	struct nilfs_sufile_header *header;
1214	void *kaddr;
1215	int err;
1216
1217	if (susize > sb->s_blocksize) {
1218		nilfs_err(sb, "too large segment usage size: %zu bytes",
1219			  susize);
1220		return -EINVAL;
1221	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1222		nilfs_err(sb, "too small segment usage size: %zu bytes",
1223			  susize);
1224		return -EINVAL;
1225	}
1226
1227	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1228	if (unlikely(!sufile))
1229		return -ENOMEM;
1230	if (!(sufile->i_state & I_NEW))
1231		goto out;
1232
1233	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1234	if (err)
1235		goto failed;
1236
1237	nilfs_mdt_set_entry_size(sufile, susize,
1238				 sizeof(struct nilfs_sufile_header));
1239
1240	err = nilfs_read_inode_common(sufile, raw_inode);
1241	if (err)
1242		goto failed;
1243
1244	err = nilfs_sufile_get_header_block(sufile, &header_bh);
1245	if (err)
1246		goto failed;
1247
1248	sui = NILFS_SUI(sufile);
1249	kaddr = kmap_atomic(header_bh->b_page);
1250	header = kaddr + bh_offset(header_bh);
1251	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1252	kunmap_atomic(kaddr);
1253	brelse(header_bh);
1254
1255	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1256	sui->allocmin = 0;
1257
1258	unlock_new_inode(sufile);
1259 out:
1260	*inodep = sufile;
1261	return 0;
1262 failed:
1263	iget_failed(sufile);
1264	return err;
1265}