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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}
v6.13.7
   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	t = div64_ul(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
  73/**
  74 * nilfs_sufile_segment_usage_offset - calculate the byte offset of a segment
  75 *                                     usage entry in the folio containing it
  76 * @sufile: segment usage file inode
  77 * @segnum: number of segment usage
  78 * @bh:     buffer head of block containing segment usage indexed by @segnum
  79 *
  80 * Return: Byte offset in the folio of the segment usage entry.
  81 */
  82static size_t nilfs_sufile_segment_usage_offset(const struct inode *sufile,
  83						__u64 segnum,
  84						struct buffer_head *bh)
  85{
  86	return offset_in_folio(bh->b_folio, bh->b_data) +
  87		nilfs_sufile_get_offset(sufile, segnum) *
  88		NILFS_MDT(sufile)->mi_entry_size;
  89}
  90
  91static int nilfs_sufile_get_header_block(struct inode *sufile,
  92					 struct buffer_head **bhp)
  93{
  94	int err = nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
  95
  96	if (unlikely(err == -ENOENT)) {
  97		nilfs_error(sufile->i_sb,
  98			    "missing header block in segment usage metadata");
  99		err = -EIO;
 100	}
 101	return err;
 102}
 103
 104static inline int
 105nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
 106				     int create, struct buffer_head **bhp)
 107{
 108	return nilfs_mdt_get_block(sufile,
 109				   nilfs_sufile_get_blkoff(sufile, segnum),
 110				   create, NULL, bhp);
 111}
 112
 113static int nilfs_sufile_delete_segment_usage_block(struct inode *sufile,
 114						   __u64 segnum)
 115{
 116	return nilfs_mdt_delete_block(sufile,
 117				      nilfs_sufile_get_blkoff(sufile, segnum));
 118}
 119
 120static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
 121				     u64 ncleanadd, u64 ndirtyadd)
 122{
 123	struct nilfs_sufile_header *header;
 
 124
 125	header = kmap_local_folio(header_bh->b_folio, 0);
 
 126	le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
 127	le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
 128	kunmap_local(header);
 129
 130	mark_buffer_dirty(header_bh);
 131}
 132
 133/**
 134 * nilfs_sufile_get_ncleansegs - return the number of clean segments
 135 * @sufile: inode of segment usage file
 136 */
 137unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile)
 138{
 139	return NILFS_SUI(sufile)->ncleansegs;
 140}
 141
 142/**
 143 * nilfs_sufile_updatev - modify multiple segment usages at a time
 144 * @sufile: inode of segment usage file
 145 * @segnumv: array of segment numbers
 146 * @nsegs: size of @segnumv array
 147 * @create: creation flag
 148 * @ndone: place to store number of modified segments on @segnumv
 149 * @dofunc: primitive operation for the update
 150 *
 151 * Description: nilfs_sufile_updatev() repeatedly calls @dofunc
 152 * against the given array of segments.  The @dofunc is called with
 153 * buffers of a header block and the sufile block in which the target
 154 * segment usage entry is contained.  If @ndone is given, the number
 155 * of successfully modified segments from the head is stored in the
 156 * place @ndone points to.
 157 *
 158 * Return Value: On success, zero is returned.  On error, one of the
 159 * following negative error codes is returned.
 160 *
 161 * %-EIO - I/O error.
 162 *
 163 * %-ENOMEM - Insufficient amount of memory available.
 164 *
 165 * %-ENOENT - Given segment usage is in hole block (may be returned if
 166 *            @create is zero)
 167 *
 168 * %-EINVAL - Invalid segment usage number
 169 */
 170int nilfs_sufile_updatev(struct inode *sufile, __u64 *segnumv, size_t nsegs,
 171			 int create, size_t *ndone,
 172			 void (*dofunc)(struct inode *, __u64,
 173					struct buffer_head *,
 174					struct buffer_head *))
 175{
 176	struct buffer_head *header_bh, *bh;
 177	unsigned long blkoff, prev_blkoff;
 178	__u64 *seg;
 179	size_t nerr = 0, n = 0;
 180	int ret = 0;
 181
 182	if (unlikely(nsegs == 0))
 183		goto out;
 184
 185	down_write(&NILFS_MDT(sufile)->mi_sem);
 186	for (seg = segnumv; seg < segnumv + nsegs; seg++) {
 187		if (unlikely(*seg >= nilfs_sufile_get_nsegments(sufile))) {
 188			nilfs_warn(sufile->i_sb,
 189				   "%s: invalid segment number: %llu",
 190				   __func__, (unsigned long long)*seg);
 191			nerr++;
 192		}
 193	}
 194	if (nerr > 0) {
 195		ret = -EINVAL;
 196		goto out_sem;
 197	}
 198
 199	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 200	if (ret < 0)
 201		goto out_sem;
 202
 203	seg = segnumv;
 204	blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 205	ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 206	if (ret < 0)
 207		goto out_header;
 208
 209	for (;;) {
 210		dofunc(sufile, *seg, header_bh, bh);
 211
 212		if (++seg >= segnumv + nsegs)
 213			break;
 214		prev_blkoff = blkoff;
 215		blkoff = nilfs_sufile_get_blkoff(sufile, *seg);
 216		if (blkoff == prev_blkoff)
 217			continue;
 218
 219		/* get different block */
 220		brelse(bh);
 221		ret = nilfs_mdt_get_block(sufile, blkoff, create, NULL, &bh);
 222		if (unlikely(ret < 0))
 223			goto out_header;
 224	}
 225	brelse(bh);
 226
 227 out_header:
 228	n = seg - segnumv;
 229	brelse(header_bh);
 230 out_sem:
 231	up_write(&NILFS_MDT(sufile)->mi_sem);
 232 out:
 233	if (ndone)
 234		*ndone = n;
 235	return ret;
 236}
 237
 238int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
 239			void (*dofunc)(struct inode *, __u64,
 240				       struct buffer_head *,
 241				       struct buffer_head *))
 242{
 243	struct buffer_head *header_bh, *bh;
 244	int ret;
 245
 246	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
 247		nilfs_warn(sufile->i_sb, "%s: invalid segment number: %llu",
 248			   __func__, (unsigned long long)segnum);
 
 249		return -EINVAL;
 250	}
 251	down_write(&NILFS_MDT(sufile)->mi_sem);
 252
 253	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 254	if (ret < 0)
 255		goto out_sem;
 256
 257	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
 258	if (!ret) {
 259		dofunc(sufile, segnum, header_bh, bh);
 260		brelse(bh);
 261	}
 262	brelse(header_bh);
 263
 264 out_sem:
 265	up_write(&NILFS_MDT(sufile)->mi_sem);
 266	return ret;
 267}
 268
 269/**
 270 * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
 271 * @sufile: inode of segment usage file
 272 * @start: minimum segment number of allocatable region (inclusive)
 273 * @end: maximum segment number of allocatable region (inclusive)
 274 *
 275 * Return Value: On success, 0 is returned.  On error, one of the
 276 * following negative error codes is returned.
 277 *
 278 * %-ERANGE - invalid segment region
 279 */
 280int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
 281{
 282	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 283	__u64 nsegs;
 284	int ret = -ERANGE;
 285
 286	down_write(&NILFS_MDT(sufile)->mi_sem);
 287	nsegs = nilfs_sufile_get_nsegments(sufile);
 288
 289	if (start <= end && end < nsegs) {
 290		sui->allocmin = start;
 291		sui->allocmax = end;
 292		ret = 0;
 293	}
 294	up_write(&NILFS_MDT(sufile)->mi_sem);
 295	return ret;
 296}
 297
 298/**
 299 * nilfs_sufile_alloc - allocate a segment
 300 * @sufile: inode of segment usage file
 301 * @segnump: pointer to segment number
 302 *
 303 * Description: nilfs_sufile_alloc() allocates a clean segment.
 304 *
 305 * Return Value: On success, 0 is returned and the segment number of the
 306 * allocated segment is stored in the place pointed by @segnump. On error, one
 307 * of the following negative error codes is returned.
 308 *
 309 * %-EIO - I/O error.
 310 *
 311 * %-ENOMEM - Insufficient amount of memory available.
 312 *
 313 * %-ENOSPC - No clean segment left.
 314 */
 315int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 316{
 317	struct buffer_head *header_bh, *su_bh;
 318	struct nilfs_sufile_header *header;
 319	struct nilfs_segment_usage *su;
 320	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 321	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 322	__u64 segnum, maxsegnum, last_alloc;
 323	size_t offset;
 324	void *kaddr;
 325	unsigned long nsegments, nsus, cnt;
 326	int ret, j;
 327
 328	down_write(&NILFS_MDT(sufile)->mi_sem);
 329
 330	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 331	if (ret < 0)
 332		goto out_sem;
 333	header = kmap_local_folio(header_bh->b_folio, 0);
 
 334	last_alloc = le64_to_cpu(header->sh_last_alloc);
 335	kunmap_local(header);
 336
 337	nsegments = nilfs_sufile_get_nsegments(sufile);
 338	maxsegnum = sui->allocmax;
 339	segnum = last_alloc + 1;
 340	if (segnum < sui->allocmin || segnum > sui->allocmax)
 341		segnum = sui->allocmin;
 342
 343	for (cnt = 0; cnt < nsegments; cnt += nsus) {
 344		if (segnum > maxsegnum) {
 345			if (cnt < sui->allocmax - sui->allocmin + 1) {
 346				/*
 347				 * wrap around in the limited region.
 348				 * if allocation started from
 349				 * sui->allocmin, this never happens.
 350				 */
 351				segnum = sui->allocmin;
 352				maxsegnum = last_alloc;
 353			} else if (segnum > sui->allocmin &&
 354				   sui->allocmax + 1 < nsegments) {
 355				segnum = sui->allocmax + 1;
 356				maxsegnum = nsegments - 1;
 357			} else if (sui->allocmin > 0)  {
 358				segnum = 0;
 359				maxsegnum = sui->allocmin - 1;
 360			} else {
 361				break; /* never happens */
 362			}
 363		}
 364		trace_nilfs2_segment_usage_check(sufile, segnum, cnt);
 365		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
 366							   &su_bh);
 367		if (ret < 0)
 368			goto out_header;
 369
 370		offset = nilfs_sufile_segment_usage_offset(sufile, segnum,
 371							   su_bh);
 372		su = kaddr = kmap_local_folio(su_bh->b_folio, offset);
 373
 374		nsus = nilfs_sufile_segment_usages_in_block(
 375			sufile, segnum, maxsegnum);
 376		for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
 377			if (!nilfs_segment_usage_clean(su))
 378				continue;
 379			/* found a clean segment */
 380			nilfs_segment_usage_set_dirty(su);
 381			kunmap_local(kaddr);
 382
 383			header = kmap_local_folio(header_bh->b_folio, 0);
 
 384			le64_add_cpu(&header->sh_ncleansegs, -1);
 385			le64_add_cpu(&header->sh_ndirtysegs, 1);
 386			header->sh_last_alloc = cpu_to_le64(segnum);
 387			kunmap_local(header);
 388
 389			sui->ncleansegs--;
 390			mark_buffer_dirty(header_bh);
 391			mark_buffer_dirty(su_bh);
 392			nilfs_mdt_mark_dirty(sufile);
 393			brelse(su_bh);
 394			*segnump = segnum;
 395
 396			trace_nilfs2_segment_usage_allocated(sufile, segnum);
 397
 398			goto out_header;
 399		}
 400
 401		kunmap_local(kaddr);
 402		brelse(su_bh);
 403	}
 404
 405	/* no segments left */
 406	ret = -ENOSPC;
 407
 408 out_header:
 409	brelse(header_bh);
 410
 411 out_sem:
 412	up_write(&NILFS_MDT(sufile)->mi_sem);
 413	return ret;
 414}
 415
 416void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
 417				 struct buffer_head *header_bh,
 418				 struct buffer_head *su_bh)
 419{
 420	struct nilfs_segment_usage *su;
 421	size_t offset;
 422
 423	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, su_bh);
 424	su = kmap_local_folio(su_bh->b_folio, offset);
 425	if (unlikely(!nilfs_segment_usage_clean(su))) {
 426		nilfs_warn(sufile->i_sb, "%s: segment %llu must be clean",
 427			   __func__, (unsigned long long)segnum);
 428		kunmap_local(su);
 
 429		return;
 430	}
 431	nilfs_segment_usage_set_dirty(su);
 432	kunmap_local(su);
 433
 434	nilfs_sufile_mod_counter(header_bh, -1, 1);
 435	NILFS_SUI(sufile)->ncleansegs--;
 436
 437	mark_buffer_dirty(su_bh);
 438	nilfs_mdt_mark_dirty(sufile);
 439}
 440
 441void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
 442			   struct buffer_head *header_bh,
 443			   struct buffer_head *su_bh)
 444{
 445	struct nilfs_segment_usage *su;
 446	size_t offset;
 447	int clean, dirty;
 448
 449	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, su_bh);
 450	su = kmap_local_folio(su_bh->b_folio, offset);
 451	if (su->su_flags == cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY)) &&
 452	    su->su_nblocks == cpu_to_le32(0)) {
 453		kunmap_local(su);
 454		return;
 455	}
 456	clean = nilfs_segment_usage_clean(su);
 457	dirty = nilfs_segment_usage_dirty(su);
 458
 459	/* make the segment garbage */
 460	su->su_lastmod = cpu_to_le64(0);
 461	su->su_nblocks = cpu_to_le32(0);
 462	su->su_flags = cpu_to_le32(BIT(NILFS_SEGMENT_USAGE_DIRTY));
 463	kunmap_local(su);
 464
 465	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
 466	NILFS_SUI(sufile)->ncleansegs -= clean;
 467
 468	mark_buffer_dirty(su_bh);
 469	nilfs_mdt_mark_dirty(sufile);
 470}
 471
 472void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
 473			  struct buffer_head *header_bh,
 474			  struct buffer_head *su_bh)
 475{
 476	struct nilfs_segment_usage *su;
 477	size_t offset;
 478	int sudirty;
 479
 480	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, su_bh);
 481	su = kmap_local_folio(su_bh->b_folio, offset);
 482	if (nilfs_segment_usage_clean(su)) {
 483		nilfs_warn(sufile->i_sb, "%s: segment %llu is already clean",
 484			   __func__, (unsigned long long)segnum);
 485		kunmap_local(su);
 
 486		return;
 487	}
 488	if (unlikely(nilfs_segment_usage_error(su)))
 489		nilfs_warn(sufile->i_sb, "free segment %llu marked in error",
 490			   (unsigned long long)segnum);
 491
 492	sudirty = nilfs_segment_usage_dirty(su);
 493	if (unlikely(!sudirty))
 494		nilfs_warn(sufile->i_sb, "free unallocated segment %llu",
 495			   (unsigned long long)segnum);
 496
 497	nilfs_segment_usage_set_clean(su);
 498	kunmap_local(su);
 499	mark_buffer_dirty(su_bh);
 500
 501	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
 502	NILFS_SUI(sufile)->ncleansegs++;
 503
 504	nilfs_mdt_mark_dirty(sufile);
 505
 506	trace_nilfs2_segment_usage_freed(sufile, segnum);
 507}
 508
 509/**
 510 * nilfs_sufile_mark_dirty - mark the buffer having a segment usage dirty
 511 * @sufile: inode of segment usage file
 512 * @segnum: segment number
 513 */
 514int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum)
 515{
 516	struct buffer_head *bh;
 517	size_t offset;
 518	struct nilfs_segment_usage *su;
 519	int ret;
 520
 521	down_write(&NILFS_MDT(sufile)->mi_sem);
 522	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 523	if (unlikely(ret)) {
 524		if (ret == -ENOENT) {
 525			nilfs_error(sufile->i_sb,
 526				    "segment usage for segment %llu is unreadable due to a hole block",
 527				    (unsigned long long)segnum);
 528			ret = -EIO;
 529		}
 530		goto out_sem;
 531	}
 532
 533	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, bh);
 534	su = kmap_local_folio(bh->b_folio, offset);
 535	if (unlikely(nilfs_segment_usage_error(su))) {
 536		struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 537
 538		kunmap_local(su);
 539		brelse(bh);
 540		if (nilfs_segment_is_active(nilfs, segnum)) {
 541			nilfs_error(sufile->i_sb,
 542				    "active segment %llu is erroneous",
 543				    (unsigned long long)segnum);
 544		} else {
 545			/*
 546			 * Segments marked erroneous are never allocated by
 547			 * nilfs_sufile_alloc(); only active segments, ie,
 548			 * the segments indexed by ns_segnum or ns_nextnum,
 549			 * can be erroneous here.
 550			 */
 551			WARN_ON_ONCE(1);
 552		}
 553		ret = -EIO;
 554	} else {
 555		nilfs_segment_usage_set_dirty(su);
 556		kunmap_local(su);
 557		mark_buffer_dirty(bh);
 558		nilfs_mdt_mark_dirty(sufile);
 559		brelse(bh);
 560	}
 561out_sem:
 562	up_write(&NILFS_MDT(sufile)->mi_sem);
 563	return ret;
 564}
 565
 566/**
 567 * nilfs_sufile_set_segment_usage - set usage of a segment
 568 * @sufile: inode of segment usage file
 569 * @segnum: segment number
 570 * @nblocks: number of live blocks in the segment
 571 * @modtime: modification time (option)
 572 */
 573int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
 574				   unsigned long nblocks, time64_t modtime)
 575{
 576	struct buffer_head *bh;
 577	struct nilfs_segment_usage *su;
 578	size_t offset;
 579	int ret;
 580
 581	down_write(&NILFS_MDT(sufile)->mi_sem);
 582	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &bh);
 583	if (ret < 0)
 584		goto out_sem;
 585
 586	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, bh);
 587	su = kmap_local_folio(bh->b_folio, offset);
 588	if (modtime) {
 589		/*
 590		 * Check segusage error and set su_lastmod only when updating
 591		 * this entry with a valid timestamp, not for cancellation.
 592		 */
 593		WARN_ON_ONCE(nilfs_segment_usage_error(su));
 594		su->su_lastmod = cpu_to_le64(modtime);
 595	}
 596	su->su_nblocks = cpu_to_le32(nblocks);
 597	kunmap_local(su);
 598
 599	mark_buffer_dirty(bh);
 600	nilfs_mdt_mark_dirty(sufile);
 601	brelse(bh);
 602
 603 out_sem:
 604	up_write(&NILFS_MDT(sufile)->mi_sem);
 605	return ret;
 606}
 607
 608/**
 609 * nilfs_sufile_get_stat - get segment usage statistics
 610 * @sufile: inode of segment usage file
 611 * @sustat: pointer to a structure of segment usage statistics
 612 *
 613 * Description: nilfs_sufile_get_stat() returns information about segment
 614 * usage.
 615 *
 616 * Return Value: On success, 0 is returned, and segment usage information is
 617 * stored in the place pointed by @sustat. On error, one of the following
 618 * negative error codes is returned.
 619 *
 620 * %-EIO - I/O error.
 621 *
 622 * %-ENOMEM - Insufficient amount of memory available.
 623 */
 624int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
 625{
 626	struct buffer_head *header_bh;
 627	struct nilfs_sufile_header *header;
 628	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 
 629	int ret;
 630
 631	down_read(&NILFS_MDT(sufile)->mi_sem);
 632
 633	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 634	if (ret < 0)
 635		goto out_sem;
 636
 637	header = kmap_local_folio(header_bh->b_folio, 0);
 
 638	sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
 639	sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
 640	sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
 641	sustat->ss_ctime = nilfs->ns_ctime;
 642	sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
 643	spin_lock(&nilfs->ns_last_segment_lock);
 644	sustat->ss_prot_seq = nilfs->ns_prot_seq;
 645	spin_unlock(&nilfs->ns_last_segment_lock);
 646	kunmap_local(header);
 647	brelse(header_bh);
 648
 649 out_sem:
 650	up_read(&NILFS_MDT(sufile)->mi_sem);
 651	return ret;
 652}
 653
 654void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
 655			       struct buffer_head *header_bh,
 656			       struct buffer_head *su_bh)
 657{
 658	struct nilfs_segment_usage *su;
 659	size_t offset;
 660	int suclean;
 661
 662	offset = nilfs_sufile_segment_usage_offset(sufile, segnum, su_bh);
 663	su = kmap_local_folio(su_bh->b_folio, offset);
 664	if (nilfs_segment_usage_error(su)) {
 665		kunmap_local(su);
 666		return;
 667	}
 668	suclean = nilfs_segment_usage_clean(su);
 669	nilfs_segment_usage_set_error(su);
 670	kunmap_local(su);
 671
 672	if (suclean) {
 673		nilfs_sufile_mod_counter(header_bh, -1, 0);
 674		NILFS_SUI(sufile)->ncleansegs--;
 675	}
 676	mark_buffer_dirty(su_bh);
 677	nilfs_mdt_mark_dirty(sufile);
 678}
 679
 680/**
 681 * nilfs_sufile_truncate_range - truncate range of segment array
 682 * @sufile: inode of segment usage file
 683 * @start: start segment number (inclusive)
 684 * @end: end segment number (inclusive)
 685 *
 686 * Return Value: On success, 0 is returned.  On error, one of the
 687 * following negative error codes is returned.
 688 *
 689 * %-EIO - I/O error.
 690 *
 691 * %-ENOMEM - Insufficient amount of memory available.
 692 *
 693 * %-EINVAL - Invalid number of segments specified
 694 *
 695 * %-EBUSY - Dirty or active segments are present in the range
 696 */
 697static int nilfs_sufile_truncate_range(struct inode *sufile,
 698				       __u64 start, __u64 end)
 699{
 700	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 701	struct buffer_head *header_bh;
 702	struct buffer_head *su_bh;
 703	struct nilfs_segment_usage *su, *su2;
 704	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 705	unsigned long segusages_per_block;
 706	unsigned long nsegs, ncleaned;
 707	__u64 segnum;
 708	size_t offset;
 709	ssize_t n, nc;
 710	int ret;
 711	int j;
 712
 713	nsegs = nilfs_sufile_get_nsegments(sufile);
 714
 715	ret = -EINVAL;
 716	if (start > end || start >= nsegs)
 717		goto out;
 718
 719	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 720	if (ret < 0)
 721		goto out;
 722
 723	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 724	ncleaned = 0;
 725
 726	for (segnum = start; segnum <= end; segnum += n) {
 727		n = min_t(unsigned long,
 728			  segusages_per_block -
 729				  nilfs_sufile_get_offset(sufile, segnum),
 730			  end - segnum + 1);
 731		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 732							   &su_bh);
 733		if (ret < 0) {
 734			if (ret != -ENOENT)
 735				goto out_header;
 736			/* hole */
 737			continue;
 738		}
 739		offset = nilfs_sufile_segment_usage_offset(sufile, segnum,
 740							   su_bh);
 741		su = kmap_local_folio(su_bh->b_folio, offset);
 742		su2 = su;
 743		for (j = 0; j < n; j++, su = (void *)su + susz) {
 744			if ((le32_to_cpu(su->su_flags) &
 745			     ~BIT(NILFS_SEGMENT_USAGE_ERROR)) ||
 746			    nilfs_segment_is_active(nilfs, segnum + j)) {
 747				ret = -EBUSY;
 748				kunmap_local(su2);
 749				brelse(su_bh);
 750				goto out_header;
 751			}
 752		}
 753		nc = 0;
 754		for (su = su2, j = 0; j < n; j++, su = (void *)su + susz) {
 755			if (nilfs_segment_usage_error(su)) {
 756				nilfs_segment_usage_set_clean(su);
 757				nc++;
 758			}
 759		}
 760		kunmap_local(su2);
 761		if (nc > 0) {
 762			mark_buffer_dirty(su_bh);
 763			ncleaned += nc;
 764		}
 765		brelse(su_bh);
 766
 767		if (n == segusages_per_block) {
 768			/* make hole */
 769			nilfs_sufile_delete_segment_usage_block(sufile, segnum);
 770		}
 771	}
 772	ret = 0;
 773
 774out_header:
 775	if (ncleaned > 0) {
 776		NILFS_SUI(sufile)->ncleansegs += ncleaned;
 777		nilfs_sufile_mod_counter(header_bh, ncleaned, 0);
 778		nilfs_mdt_mark_dirty(sufile);
 779	}
 780	brelse(header_bh);
 781out:
 782	return ret;
 783}
 784
 785/**
 786 * nilfs_sufile_resize - resize segment array
 787 * @sufile: inode of segment usage file
 788 * @newnsegs: new number of segments
 789 *
 790 * Return Value: On success, 0 is returned.  On error, one of the
 791 * following negative error codes is returned.
 792 *
 793 * %-EIO - I/O error.
 794 *
 795 * %-ENOMEM - Insufficient amount of memory available.
 796 *
 797 * %-ENOSPC - Enough free space is not left for shrinking
 798 *
 799 * %-EBUSY - Dirty or active segments exist in the region to be truncated
 800 */
 801int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
 802{
 803	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 804	struct buffer_head *header_bh;
 805	struct nilfs_sufile_header *header;
 806	struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
 
 807	unsigned long nsegs, nrsvsegs;
 808	int ret = 0;
 809
 810	down_write(&NILFS_MDT(sufile)->mi_sem);
 811
 812	nsegs = nilfs_sufile_get_nsegments(sufile);
 813	if (nsegs == newnsegs)
 814		goto out;
 815
 816	ret = -ENOSPC;
 817	nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
 818	if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
 819		goto out;
 820
 821	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 822	if (ret < 0)
 823		goto out;
 824
 825	if (newnsegs > nsegs) {
 826		sui->ncleansegs += newnsegs - nsegs;
 827	} else /* newnsegs < nsegs */ {
 828		ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
 829		if (ret < 0)
 830			goto out_header;
 831
 832		sui->ncleansegs -= nsegs - newnsegs;
 833
 834		/*
 835		 * If the sufile is successfully truncated, immediately adjust
 836		 * the segment allocation space while locking the semaphore
 837		 * "mi_sem" so that nilfs_sufile_alloc() never allocates
 838		 * segments in the truncated space.
 839		 */
 840		sui->allocmax = newnsegs - 1;
 841		sui->allocmin = 0;
 842	}
 843
 844	header = kmap_local_folio(header_bh->b_folio, 0);
 
 845	header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
 846	kunmap_local(header);
 847
 848	mark_buffer_dirty(header_bh);
 849	nilfs_mdt_mark_dirty(sufile);
 850	nilfs_set_nsegments(nilfs, newnsegs);
 851
 852out_header:
 853	brelse(header_bh);
 854out:
 855	up_write(&NILFS_MDT(sufile)->mi_sem);
 856	return ret;
 857}
 858
 859/**
 860 * nilfs_sufile_get_suinfo - get segment usage information
 861 * @sufile: inode of segment usage file
 862 * @segnum: segment number to start looking
 863 * @buf:    array of suinfo
 864 * @sisz:   byte size of suinfo
 865 * @nsi:    size of suinfo array
 866 *
 867 * Return: Count of segment usage info items stored in the output buffer on
 868 * success, or the following negative error code on failure.
 869 * * %-EIO	- I/O error (including metadata corruption).
 870 * * %-ENOMEM	- Insufficient memory available.
 
 
 
 
 871 */
 872ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum, void *buf,
 873				unsigned int sisz, size_t nsi)
 874{
 875	struct buffer_head *su_bh;
 876	struct nilfs_segment_usage *su;
 877	struct nilfs_suinfo *si = buf;
 878	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
 879	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 880	size_t offset;
 881	void *kaddr;
 882	unsigned long nsegs, segusages_per_block;
 883	ssize_t n;
 884	int ret, i, j;
 885
 886	down_read(&NILFS_MDT(sufile)->mi_sem);
 887
 888	segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
 889	nsegs = min_t(unsigned long,
 890		      nilfs_sufile_get_nsegments(sufile) - segnum,
 891		      nsi);
 892	for (i = 0; i < nsegs; i += n, segnum += n) {
 893		n = min_t(unsigned long,
 894			  segusages_per_block -
 895				  nilfs_sufile_get_offset(sufile, segnum),
 896			  nsegs - i);
 897		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
 898							   &su_bh);
 899		if (ret < 0) {
 900			if (ret != -ENOENT)
 901				goto out;
 902			/* hole */
 903			memset(si, 0, sisz * n);
 904			si = (void *)si + sisz * n;
 905			continue;
 906		}
 907
 908		offset = nilfs_sufile_segment_usage_offset(sufile, segnum,
 909							   su_bh);
 910		su = kaddr = kmap_local_folio(su_bh->b_folio, offset);
 911		for (j = 0; j < n;
 912		     j++, su = (void *)su + susz, si = (void *)si + sisz) {
 913			si->sui_lastmod = le64_to_cpu(su->su_lastmod);
 914			si->sui_nblocks = le32_to_cpu(su->su_nblocks);
 915			si->sui_flags = le32_to_cpu(su->su_flags) &
 916				~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 917			if (nilfs_segment_is_active(nilfs, segnum + j))
 918				si->sui_flags |=
 919					BIT(NILFS_SEGMENT_USAGE_ACTIVE);
 920		}
 921		kunmap_local(kaddr);
 922		brelse(su_bh);
 923	}
 924	ret = nsegs;
 925
 926 out:
 927	up_read(&NILFS_MDT(sufile)->mi_sem);
 928	return ret;
 929}
 930
 931/**
 932 * nilfs_sufile_set_suinfo - sets segment usage info
 933 * @sufile: inode of segment usage file
 934 * @buf: array of suinfo_update
 935 * @supsz: byte size of suinfo_update
 936 * @nsup: size of suinfo_update array
 937 *
 938 * Description: Takes an array of nilfs_suinfo_update structs and updates
 939 * segment usage accordingly. Only the fields indicated by the sup_flags
 940 * are updated.
 941 *
 942 * Return Value: On success, 0 is returned. On error, one of the
 943 * following negative error codes is returned.
 944 *
 945 * %-EIO - I/O error.
 946 *
 947 * %-ENOMEM - Insufficient amount of memory available.
 948 *
 949 * %-EINVAL - Invalid values in input (segment number, flags or nblocks)
 950 */
 951ssize_t nilfs_sufile_set_suinfo(struct inode *sufile, void *buf,
 952				unsigned int supsz, size_t nsup)
 953{
 954	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
 955	struct buffer_head *header_bh, *bh;
 956	struct nilfs_suinfo_update *sup, *supend = buf + supsz * nsup;
 957	struct nilfs_segment_usage *su;
 958	size_t offset;
 959	unsigned long blkoff, prev_blkoff;
 960	int cleansi, cleansu, dirtysi, dirtysu;
 961	long ncleaned = 0, ndirtied = 0;
 962	int ret = 0;
 963
 964	if (unlikely(nsup == 0))
 965		return ret;
 966
 967	for (sup = buf; sup < supend; sup = (void *)sup + supsz) {
 968		if (sup->sup_segnum >= nilfs->ns_nsegments
 969			|| (sup->sup_flags &
 970				(~0UL << __NR_NILFS_SUINFO_UPDATE_FIELDS))
 971			|| (nilfs_suinfo_update_nblocks(sup) &&
 972				sup->sup_sui.sui_nblocks >
 973				nilfs->ns_blocks_per_segment))
 974			return -EINVAL;
 975	}
 976
 977	down_write(&NILFS_MDT(sufile)->mi_sem);
 978
 979	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 980	if (ret < 0)
 981		goto out_sem;
 982
 983	sup = buf;
 984	blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
 985	ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
 986	if (ret < 0)
 987		goto out_header;
 988
 989	for (;;) {
 990		offset = nilfs_sufile_segment_usage_offset(
 991			sufile, sup->sup_segnum, bh);
 992		su = kmap_local_folio(bh->b_folio, offset);
 993
 994		if (nilfs_suinfo_update_lastmod(sup))
 995			su->su_lastmod = cpu_to_le64(sup->sup_sui.sui_lastmod);
 996
 997		if (nilfs_suinfo_update_nblocks(sup))
 998			su->su_nblocks = cpu_to_le32(sup->sup_sui.sui_nblocks);
 999
1000		if (nilfs_suinfo_update_flags(sup)) {
1001			/*
1002			 * Active flag is a virtual flag projected by running
1003			 * nilfs kernel code - drop it not to write it to
1004			 * disk.
1005			 */
1006			sup->sup_sui.sui_flags &=
1007					~BIT(NILFS_SEGMENT_USAGE_ACTIVE);
1008
1009			cleansi = nilfs_suinfo_clean(&sup->sup_sui);
1010			cleansu = nilfs_segment_usage_clean(su);
1011			dirtysi = nilfs_suinfo_dirty(&sup->sup_sui);
1012			dirtysu = nilfs_segment_usage_dirty(su);
1013
1014			if (cleansi && !cleansu)
1015				++ncleaned;
1016			else if (!cleansi && cleansu)
1017				--ncleaned;
1018
1019			if (dirtysi && !dirtysu)
1020				++ndirtied;
1021			else if (!dirtysi && dirtysu)
1022				--ndirtied;
1023
1024			su->su_flags = cpu_to_le32(sup->sup_sui.sui_flags);
1025		}
1026
1027		kunmap_local(su);
1028
1029		sup = (void *)sup + supsz;
1030		if (sup >= supend)
1031			break;
1032
1033		prev_blkoff = blkoff;
1034		blkoff = nilfs_sufile_get_blkoff(sufile, sup->sup_segnum);
1035		if (blkoff == prev_blkoff)
1036			continue;
1037
1038		/* get different block */
1039		mark_buffer_dirty(bh);
1040		put_bh(bh);
1041		ret = nilfs_mdt_get_block(sufile, blkoff, 1, NULL, &bh);
1042		if (unlikely(ret < 0))
1043			goto out_mark;
1044	}
1045	mark_buffer_dirty(bh);
1046	put_bh(bh);
1047
1048 out_mark:
1049	if (ncleaned || ndirtied) {
1050		nilfs_sufile_mod_counter(header_bh, (u64)ncleaned,
1051				(u64)ndirtied);
1052		NILFS_SUI(sufile)->ncleansegs += ncleaned;
1053	}
1054	nilfs_mdt_mark_dirty(sufile);
1055 out_header:
1056	put_bh(header_bh);
1057 out_sem:
1058	up_write(&NILFS_MDT(sufile)->mi_sem);
1059	return ret;
1060}
1061
1062/**
1063 * nilfs_sufile_trim_fs() - trim ioctl handle function
1064 * @sufile: inode of segment usage file
1065 * @range: fstrim_range structure
1066 *
1067 * start:	First Byte to trim
1068 * len:		number of Bytes to trim from start
1069 * minlen:	minimum extent length in Bytes
1070 *
1071 * Decription: nilfs_sufile_trim_fs goes through all segments containing bytes
1072 * from start to start+len. start is rounded up to the next block boundary
1073 * and start+len is rounded down. For each clean segment blkdev_issue_discard
1074 * function is invoked.
1075 *
1076 * Return Value: On success, 0 is returned or negative error code, otherwise.
1077 */
1078int nilfs_sufile_trim_fs(struct inode *sufile, struct fstrim_range *range)
1079{
1080	struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
1081	struct buffer_head *su_bh;
1082	struct nilfs_segment_usage *su;
1083	size_t offset;
1084	void *kaddr;
1085	size_t n, i, susz = NILFS_MDT(sufile)->mi_entry_size;
1086	sector_t seg_start, seg_end, start_block, end_block;
1087	sector_t start = 0, nblocks = 0;
1088	u64 segnum, segnum_end, minlen, len, max_blocks, ndiscarded = 0;
1089	int ret = 0;
1090	unsigned int sects_per_block;
1091
1092	sects_per_block = (1 << nilfs->ns_blocksize_bits) /
1093			bdev_logical_block_size(nilfs->ns_bdev);
1094	len = range->len >> nilfs->ns_blocksize_bits;
1095	minlen = range->minlen >> nilfs->ns_blocksize_bits;
1096	max_blocks = ((u64)nilfs->ns_nsegments * nilfs->ns_blocks_per_segment);
1097
1098	if (!len || range->start >= max_blocks << nilfs->ns_blocksize_bits)
1099		return -EINVAL;
1100
1101	start_block = (range->start + nilfs->ns_blocksize - 1) >>
1102			nilfs->ns_blocksize_bits;
1103
1104	/*
1105	 * range->len can be very large (actually, it is set to
1106	 * ULLONG_MAX by default) - truncate upper end of the range
1107	 * carefully so as not to overflow.
1108	 */
1109	if (max_blocks - start_block < len)
1110		end_block = max_blocks - 1;
1111	else
1112		end_block = start_block + len - 1;
1113
1114	segnum = nilfs_get_segnum_of_block(nilfs, start_block);
1115	segnum_end = nilfs_get_segnum_of_block(nilfs, end_block);
1116
1117	down_read(&NILFS_MDT(sufile)->mi_sem);
1118
1119	while (segnum <= segnum_end) {
1120		n = nilfs_sufile_segment_usages_in_block(sufile, segnum,
1121				segnum_end);
1122
1123		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
1124							   &su_bh);
1125		if (ret < 0) {
1126			if (ret != -ENOENT)
1127				goto out_sem;
1128			/* hole */
1129			segnum += n;
1130			continue;
1131		}
1132
1133		offset = nilfs_sufile_segment_usage_offset(sufile, segnum,
1134							   su_bh);
1135		su = kaddr = kmap_local_folio(su_bh->b_folio, offset);
1136		for (i = 0; i < n; ++i, ++segnum, su = (void *)su + susz) {
1137			if (!nilfs_segment_usage_clean(su))
1138				continue;
1139
1140			nilfs_get_segment_range(nilfs, segnum, &seg_start,
1141						&seg_end);
1142
1143			if (!nblocks) {
1144				/* start new extent */
1145				start = seg_start;
1146				nblocks = seg_end - seg_start + 1;
1147				continue;
1148			}
1149
1150			if (start + nblocks == seg_start) {
1151				/* add to previous extent */
1152				nblocks += seg_end - seg_start + 1;
1153				continue;
1154			}
1155
1156			/* discard previous extent */
1157			if (start < start_block) {
1158				nblocks -= start_block - start;
1159				start = start_block;
1160			}
1161
1162			if (nblocks >= minlen) {
1163				kunmap_local(kaddr);
1164
1165				ret = blkdev_issue_discard(nilfs->ns_bdev,
1166						start * sects_per_block,
1167						nblocks * sects_per_block,
1168						GFP_NOFS);
1169				if (ret < 0) {
1170					put_bh(su_bh);
1171					goto out_sem;
1172				}
1173
1174				ndiscarded += nblocks;
1175				offset = nilfs_sufile_segment_usage_offset(
1176					sufile, segnum, su_bh);
1177				su = kaddr = kmap_local_folio(su_bh->b_folio,
1178							      offset);
1179			}
1180
1181			/* start new extent */
1182			start = seg_start;
1183			nblocks = seg_end - seg_start + 1;
1184		}
1185		kunmap_local(kaddr);
1186		put_bh(su_bh);
1187	}
1188
1189
1190	if (nblocks) {
1191		/* discard last extent */
1192		if (start < start_block) {
1193			nblocks -= start_block - start;
1194			start = start_block;
1195		}
1196		if (start + nblocks > end_block + 1)
1197			nblocks = end_block - start + 1;
1198
1199		if (nblocks >= minlen) {
1200			ret = blkdev_issue_discard(nilfs->ns_bdev,
1201					start * sects_per_block,
1202					nblocks * sects_per_block,
1203					GFP_NOFS);
1204			if (!ret)
1205				ndiscarded += nblocks;
1206		}
1207	}
1208
1209out_sem:
1210	up_read(&NILFS_MDT(sufile)->mi_sem);
1211
1212	range->len = ndiscarded << nilfs->ns_blocksize_bits;
1213	return ret;
1214}
1215
1216/**
1217 * nilfs_sufile_read - read or get sufile inode
1218 * @sb: super block instance
1219 * @susize: size of a segment usage entry
1220 * @raw_inode: on-disk sufile inode
1221 * @inodep: buffer to store the inode
1222 */
1223int nilfs_sufile_read(struct super_block *sb, size_t susize,
1224		      struct nilfs_inode *raw_inode, struct inode **inodep)
1225{
1226	struct inode *sufile;
1227	struct nilfs_sufile_info *sui;
1228	struct buffer_head *header_bh;
1229	struct nilfs_sufile_header *header;
 
1230	int err;
1231
1232	if (susize > sb->s_blocksize) {
1233		nilfs_err(sb, "too large segment usage size: %zu bytes",
1234			  susize);
1235		return -EINVAL;
1236	} else if (susize < NILFS_MIN_SEGMENT_USAGE_SIZE) {
1237		nilfs_err(sb, "too small segment usage size: %zu bytes",
1238			  susize);
1239		return -EINVAL;
1240	}
1241
1242	sufile = nilfs_iget_locked(sb, NULL, NILFS_SUFILE_INO);
1243	if (unlikely(!sufile))
1244		return -ENOMEM;
1245	if (!(sufile->i_state & I_NEW))
1246		goto out;
1247
1248	err = nilfs_mdt_init(sufile, NILFS_MDT_GFP, sizeof(*sui));
1249	if (err)
1250		goto failed;
1251
1252	nilfs_mdt_set_entry_size(sufile, susize,
1253				 sizeof(struct nilfs_sufile_header));
1254
1255	err = nilfs_read_inode_common(sufile, raw_inode);
1256	if (err)
1257		goto failed;
1258
1259	err = nilfs_mdt_get_block(sufile, 0, 0, NULL, &header_bh);
1260	if (unlikely(err)) {
1261		if (err == -ENOENT) {
1262			nilfs_err(sb,
1263				  "missing header block in segment usage metadata");
1264			err = -EINVAL;
1265		}
1266		goto failed;
1267	}
1268
1269	sui = NILFS_SUI(sufile);
1270	header = kmap_local_folio(header_bh->b_folio, 0);
 
1271	sui->ncleansegs = le64_to_cpu(header->sh_ncleansegs);
1272	kunmap_local(header);
1273	brelse(header_bh);
1274
1275	sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
1276	sui->allocmin = 0;
1277
1278	unlock_new_inode(sufile);
1279 out:
1280	*inodep = sufile;
1281	return 0;
1282 failed:
1283	iget_failed(sufile);
1284	return err;
1285}