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v6.8
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * NILFS segment constructor.
   4 *
   5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Written by Ryusuke Konishi.
   8 *
   9 */
  10
  11#include <linux/pagemap.h>
  12#include <linux/buffer_head.h>
  13#include <linux/writeback.h>
  14#include <linux/bitops.h>
  15#include <linux/bio.h>
  16#include <linux/completion.h>
  17#include <linux/blkdev.h>
  18#include <linux/backing-dev.h>
  19#include <linux/freezer.h>
  20#include <linux/kthread.h>
  21#include <linux/crc32.h>
  22#include <linux/pagevec.h>
  23#include <linux/slab.h>
  24#include <linux/sched/signal.h>
  25
  26#include "nilfs.h"
  27#include "btnode.h"
  28#include "page.h"
  29#include "segment.h"
  30#include "sufile.h"
  31#include "cpfile.h"
  32#include "ifile.h"
  33#include "segbuf.h"
  34
  35
  36/*
  37 * Segment constructor
  38 */
  39#define SC_N_INODEVEC	16   /* Size of locally allocated inode vector */
  40
  41#define SC_MAX_SEGDELTA 64   /*
  42			      * Upper limit of the number of segments
  43			      * appended in collection retry loop
  44			      */
  45
  46/* Construction mode */
  47enum {
  48	SC_LSEG_SR = 1,	/* Make a logical segment having a super root */
  49	SC_LSEG_DSYNC,	/*
  50			 * Flush data blocks of a given file and make
  51			 * a logical segment without a super root.
  52			 */
  53	SC_FLUSH_FILE,	/*
  54			 * Flush data files, leads to segment writes without
  55			 * creating a checkpoint.
  56			 */
  57	SC_FLUSH_DAT,	/*
  58			 * Flush DAT file.  This also creates segments
  59			 * without a checkpoint.
  60			 */
  61};
  62
  63/* Stage numbers of dirty block collection */
  64enum {
  65	NILFS_ST_INIT = 0,
  66	NILFS_ST_GC,		/* Collecting dirty blocks for GC */
  67	NILFS_ST_FILE,
  68	NILFS_ST_IFILE,
  69	NILFS_ST_CPFILE,
  70	NILFS_ST_SUFILE,
  71	NILFS_ST_DAT,
  72	NILFS_ST_SR,		/* Super root */
  73	NILFS_ST_DSYNC,		/* Data sync blocks */
  74	NILFS_ST_DONE,
  75};
  76
  77#define CREATE_TRACE_POINTS
  78#include <trace/events/nilfs2.h>
  79
  80/*
  81 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
  82 * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
  83 * the variable must use them because transition of stage count must involve
  84 * trace events (trace_nilfs2_collection_stage_transition).
  85 *
  86 * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
  87 * produce tracepoint events. It is provided just for making the intention
  88 * clear.
  89 */
  90static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
  91{
  92	sci->sc_stage.scnt++;
  93	trace_nilfs2_collection_stage_transition(sci);
  94}
  95
  96static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
  97{
  98	sci->sc_stage.scnt = next_scnt;
  99	trace_nilfs2_collection_stage_transition(sci);
 100}
 101
 102static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
 103{
 104	return sci->sc_stage.scnt;
 105}
 106
 107/* State flags of collection */
 108#define NILFS_CF_NODE		0x0001	/* Collecting node blocks */
 109#define NILFS_CF_IFILE_STARTED	0x0002	/* IFILE stage has started */
 110#define NILFS_CF_SUFREED	0x0004	/* segment usages has been freed */
 111#define NILFS_CF_HISTORY_MASK	(NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
 112
 113/* Operations depending on the construction mode and file type */
 114struct nilfs_sc_operations {
 115	int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
 116			    struct inode *);
 117	int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
 118			    struct inode *);
 119	int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
 120			    struct inode *);
 121	void (*write_data_binfo)(struct nilfs_sc_info *,
 122				 struct nilfs_segsum_pointer *,
 123				 union nilfs_binfo *);
 124	void (*write_node_binfo)(struct nilfs_sc_info *,
 125				 struct nilfs_segsum_pointer *,
 126				 union nilfs_binfo *);
 127};
 128
 129/*
 130 * Other definitions
 131 */
 132static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
 133static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
 134static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
 135static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
 136
 137#define nilfs_cnt32_ge(a, b)   \
 138	(typecheck(__u32, a) && typecheck(__u32, b) && \
 139	 ((__s32)(a) - (__s32)(b) >= 0))
 140
 141static int nilfs_prepare_segment_lock(struct super_block *sb,
 142				      struct nilfs_transaction_info *ti)
 143{
 144	struct nilfs_transaction_info *cur_ti = current->journal_info;
 145	void *save = NULL;
 146
 147	if (cur_ti) {
 148		if (cur_ti->ti_magic == NILFS_TI_MAGIC)
 149			return ++cur_ti->ti_count;
 150
 151		/*
 152		 * If journal_info field is occupied by other FS,
 153		 * it is saved and will be restored on
 154		 * nilfs_transaction_commit().
 155		 */
 156		nilfs_warn(sb, "journal info from a different FS");
 157		save = current->journal_info;
 158	}
 159	if (!ti) {
 160		ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
 161		if (!ti)
 162			return -ENOMEM;
 163		ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
 164	} else {
 165		ti->ti_flags = 0;
 166	}
 167	ti->ti_count = 0;
 168	ti->ti_save = save;
 169	ti->ti_magic = NILFS_TI_MAGIC;
 170	current->journal_info = ti;
 171	return 0;
 172}
 173
 174/**
 175 * nilfs_transaction_begin - start indivisible file operations.
 176 * @sb: super block
 177 * @ti: nilfs_transaction_info
 178 * @vacancy_check: flags for vacancy rate checks
 179 *
 180 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
 181 * the segment semaphore, to make a segment construction and write tasks
 182 * exclusive.  The function is used with nilfs_transaction_commit() in pairs.
 183 * The region enclosed by these two functions can be nested.  To avoid a
 184 * deadlock, the semaphore is only acquired or released in the outermost call.
 185 *
 186 * This function allocates a nilfs_transaction_info struct to keep context
 187 * information on it.  It is initialized and hooked onto the current task in
 188 * the outermost call.  If a pre-allocated struct is given to @ti, it is used
 189 * instead; otherwise a new struct is assigned from a slab.
 190 *
 191 * When @vacancy_check flag is set, this function will check the amount of
 192 * free space, and will wait for the GC to reclaim disk space if low capacity.
 193 *
 194 * Return Value: On success, 0 is returned. On error, one of the following
 195 * negative error code is returned.
 196 *
 197 * %-ENOMEM - Insufficient memory available.
 198 *
 199 * %-ENOSPC - No space left on device
 200 */
 201int nilfs_transaction_begin(struct super_block *sb,
 202			    struct nilfs_transaction_info *ti,
 203			    int vacancy_check)
 204{
 205	struct the_nilfs *nilfs;
 206	int ret = nilfs_prepare_segment_lock(sb, ti);
 207	struct nilfs_transaction_info *trace_ti;
 208
 209	if (unlikely(ret < 0))
 210		return ret;
 211	if (ret > 0) {
 212		trace_ti = current->journal_info;
 213
 214		trace_nilfs2_transaction_transition(sb, trace_ti,
 215				    trace_ti->ti_count, trace_ti->ti_flags,
 216				    TRACE_NILFS2_TRANSACTION_BEGIN);
 217		return 0;
 218	}
 219
 220	sb_start_intwrite(sb);
 221
 222	nilfs = sb->s_fs_info;
 223	down_read(&nilfs->ns_segctor_sem);
 224	if (vacancy_check && nilfs_near_disk_full(nilfs)) {
 225		up_read(&nilfs->ns_segctor_sem);
 226		ret = -ENOSPC;
 227		goto failed;
 228	}
 229
 230	trace_ti = current->journal_info;
 231	trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
 232					    trace_ti->ti_flags,
 233					    TRACE_NILFS2_TRANSACTION_BEGIN);
 234	return 0;
 235
 236 failed:
 237	ti = current->journal_info;
 238	current->journal_info = ti->ti_save;
 239	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 240		kmem_cache_free(nilfs_transaction_cachep, ti);
 241	sb_end_intwrite(sb);
 242	return ret;
 243}
 244
 245/**
 246 * nilfs_transaction_commit - commit indivisible file operations.
 247 * @sb: super block
 248 *
 249 * nilfs_transaction_commit() releases the read semaphore which is
 250 * acquired by nilfs_transaction_begin(). This is only performed
 251 * in outermost call of this function.  If a commit flag is set,
 252 * nilfs_transaction_commit() sets a timer to start the segment
 253 * constructor.  If a sync flag is set, it starts construction
 254 * directly.
 255 */
 256int nilfs_transaction_commit(struct super_block *sb)
 257{
 258	struct nilfs_transaction_info *ti = current->journal_info;
 259	struct the_nilfs *nilfs = sb->s_fs_info;
 260	int err = 0;
 261
 262	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 263	ti->ti_flags |= NILFS_TI_COMMIT;
 264	if (ti->ti_count > 0) {
 265		ti->ti_count--;
 266		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 267			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
 268		return 0;
 269	}
 270	if (nilfs->ns_writer) {
 271		struct nilfs_sc_info *sci = nilfs->ns_writer;
 272
 273		if (ti->ti_flags & NILFS_TI_COMMIT)
 274			nilfs_segctor_start_timer(sci);
 275		if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
 276			nilfs_segctor_do_flush(sci, 0);
 277	}
 278	up_read(&nilfs->ns_segctor_sem);
 279	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 280			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
 281
 282	current->journal_info = ti->ti_save;
 283
 284	if (ti->ti_flags & NILFS_TI_SYNC)
 285		err = nilfs_construct_segment(sb);
 286	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 287		kmem_cache_free(nilfs_transaction_cachep, ti);
 288	sb_end_intwrite(sb);
 289	return err;
 290}
 291
 292void nilfs_transaction_abort(struct super_block *sb)
 293{
 294	struct nilfs_transaction_info *ti = current->journal_info;
 295	struct the_nilfs *nilfs = sb->s_fs_info;
 296
 297	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 298	if (ti->ti_count > 0) {
 299		ti->ti_count--;
 300		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 301			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
 302		return;
 303	}
 304	up_read(&nilfs->ns_segctor_sem);
 305
 306	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 307		    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
 308
 309	current->journal_info = ti->ti_save;
 310	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 311		kmem_cache_free(nilfs_transaction_cachep, ti);
 312	sb_end_intwrite(sb);
 313}
 314
 315void nilfs_relax_pressure_in_lock(struct super_block *sb)
 316{
 317	struct the_nilfs *nilfs = sb->s_fs_info;
 318	struct nilfs_sc_info *sci = nilfs->ns_writer;
 319
 320	if (sb_rdonly(sb) || unlikely(!sci) || !sci->sc_flush_request)
 321		return;
 322
 323	set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
 324	up_read(&nilfs->ns_segctor_sem);
 325
 326	down_write(&nilfs->ns_segctor_sem);
 327	if (sci->sc_flush_request &&
 328	    test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
 329		struct nilfs_transaction_info *ti = current->journal_info;
 330
 331		ti->ti_flags |= NILFS_TI_WRITER;
 332		nilfs_segctor_do_immediate_flush(sci);
 333		ti->ti_flags &= ~NILFS_TI_WRITER;
 334	}
 335	downgrade_write(&nilfs->ns_segctor_sem);
 336}
 337
 338static void nilfs_transaction_lock(struct super_block *sb,
 339				   struct nilfs_transaction_info *ti,
 340				   int gcflag)
 341{
 342	struct nilfs_transaction_info *cur_ti = current->journal_info;
 343	struct the_nilfs *nilfs = sb->s_fs_info;
 344	struct nilfs_sc_info *sci = nilfs->ns_writer;
 345
 346	WARN_ON(cur_ti);
 347	ti->ti_flags = NILFS_TI_WRITER;
 348	ti->ti_count = 0;
 349	ti->ti_save = cur_ti;
 350	ti->ti_magic = NILFS_TI_MAGIC;
 351	current->journal_info = ti;
 352
 353	for (;;) {
 354		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 355			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
 356
 357		down_write(&nilfs->ns_segctor_sem);
 358		if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
 359			break;
 360
 361		nilfs_segctor_do_immediate_flush(sci);
 362
 363		up_write(&nilfs->ns_segctor_sem);
 364		cond_resched();
 365	}
 366	if (gcflag)
 367		ti->ti_flags |= NILFS_TI_GC;
 368
 369	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 370			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
 371}
 372
 373static void nilfs_transaction_unlock(struct super_block *sb)
 374{
 375	struct nilfs_transaction_info *ti = current->journal_info;
 376	struct the_nilfs *nilfs = sb->s_fs_info;
 377
 378	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 379	BUG_ON(ti->ti_count > 0);
 380
 381	up_write(&nilfs->ns_segctor_sem);
 382	current->journal_info = ti->ti_save;
 383
 384	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 385			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
 386}
 387
 388static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
 389					    struct nilfs_segsum_pointer *ssp,
 390					    unsigned int bytes)
 391{
 392	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 393	unsigned int blocksize = sci->sc_super->s_blocksize;
 394	void *p;
 395
 396	if (unlikely(ssp->offset + bytes > blocksize)) {
 397		ssp->offset = 0;
 398		BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
 399					       &segbuf->sb_segsum_buffers));
 400		ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
 401	}
 402	p = ssp->bh->b_data + ssp->offset;
 403	ssp->offset += bytes;
 404	return p;
 405}
 406
 407/**
 408 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
 409 * @sci: nilfs_sc_info
 410 */
 411static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
 412{
 413	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 414	struct buffer_head *sumbh;
 415	unsigned int sumbytes;
 416	unsigned int flags = 0;
 417	int err;
 418
 419	if (nilfs_doing_gc())
 420		flags = NILFS_SS_GC;
 421	err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
 422	if (unlikely(err))
 423		return err;
 424
 425	sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
 426	sumbytes = segbuf->sb_sum.sumbytes;
 427	sci->sc_finfo_ptr.bh = sumbh;  sci->sc_finfo_ptr.offset = sumbytes;
 428	sci->sc_binfo_ptr.bh = sumbh;  sci->sc_binfo_ptr.offset = sumbytes;
 429	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 430	return 0;
 431}
 432
 433/**
 434 * nilfs_segctor_zeropad_segsum - zero pad the rest of the segment summary area
 435 * @sci: segment constructor object
 436 *
 437 * nilfs_segctor_zeropad_segsum() zero-fills unallocated space at the end of
 438 * the current segment summary block.
 439 */
 440static void nilfs_segctor_zeropad_segsum(struct nilfs_sc_info *sci)
 441{
 442	struct nilfs_segsum_pointer *ssp;
 443
 444	ssp = sci->sc_blk_cnt > 0 ? &sci->sc_binfo_ptr : &sci->sc_finfo_ptr;
 445	if (ssp->offset < ssp->bh->b_size)
 446		memset(ssp->bh->b_data + ssp->offset, 0,
 447		       ssp->bh->b_size - ssp->offset);
 448}
 449
 450static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 451{
 452	sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
 453	if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
 454		return -E2BIG; /*
 455				* The current segment is filled up
 456				* (internal code)
 457				*/
 458	nilfs_segctor_zeropad_segsum(sci);
 459	sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
 460	return nilfs_segctor_reset_segment_buffer(sci);
 461}
 462
 463static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
 464{
 465	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 466	int err;
 467
 468	if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
 469		err = nilfs_segctor_feed_segment(sci);
 470		if (err)
 471			return err;
 472		segbuf = sci->sc_curseg;
 473	}
 474	err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
 475	if (likely(!err))
 476		segbuf->sb_sum.flags |= NILFS_SS_SR;
 477	return err;
 478}
 479
 480/*
 481 * Functions for making segment summary and payloads
 482 */
 483static int nilfs_segctor_segsum_block_required(
 484	struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
 485	unsigned int binfo_size)
 486{
 487	unsigned int blocksize = sci->sc_super->s_blocksize;
 488	/* Size of finfo and binfo is enough small against blocksize */
 489
 490	return ssp->offset + binfo_size +
 491		(!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
 492		blocksize;
 493}
 494
 495static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
 496				      struct inode *inode)
 497{
 498	sci->sc_curseg->sb_sum.nfinfo++;
 499	sci->sc_binfo_ptr = sci->sc_finfo_ptr;
 500	nilfs_segctor_map_segsum_entry(
 501		sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
 502
 503	if (NILFS_I(inode)->i_root &&
 504	    !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
 505		set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
 506	/* skip finfo */
 507}
 508
 509static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
 510				    struct inode *inode)
 511{
 512	struct nilfs_finfo *finfo;
 513	struct nilfs_inode_info *ii;
 514	struct nilfs_segment_buffer *segbuf;
 515	__u64 cno;
 516
 517	if (sci->sc_blk_cnt == 0)
 518		return;
 519
 520	ii = NILFS_I(inode);
 521
 522	if (test_bit(NILFS_I_GCINODE, &ii->i_state))
 523		cno = ii->i_cno;
 524	else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
 525		cno = 0;
 526	else
 527		cno = sci->sc_cno;
 528
 529	finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
 530						 sizeof(*finfo));
 531	finfo->fi_ino = cpu_to_le64(inode->i_ino);
 532	finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
 533	finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
 534	finfo->fi_cno = cpu_to_le64(cno);
 535
 536	segbuf = sci->sc_curseg;
 537	segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
 538		sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
 539	sci->sc_finfo_ptr = sci->sc_binfo_ptr;
 540	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 541}
 542
 543static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
 544					struct buffer_head *bh,
 545					struct inode *inode,
 546					unsigned int binfo_size)
 547{
 548	struct nilfs_segment_buffer *segbuf;
 549	int required, err = 0;
 550
 551 retry:
 552	segbuf = sci->sc_curseg;
 553	required = nilfs_segctor_segsum_block_required(
 554		sci, &sci->sc_binfo_ptr, binfo_size);
 555	if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
 556		nilfs_segctor_end_finfo(sci, inode);
 557		err = nilfs_segctor_feed_segment(sci);
 558		if (err)
 559			return err;
 560		goto retry;
 561	}
 562	if (unlikely(required)) {
 563		nilfs_segctor_zeropad_segsum(sci);
 564		err = nilfs_segbuf_extend_segsum(segbuf);
 565		if (unlikely(err))
 566			goto failed;
 567	}
 568	if (sci->sc_blk_cnt == 0)
 569		nilfs_segctor_begin_finfo(sci, inode);
 570
 571	nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
 572	/* Substitution to vblocknr is delayed until update_blocknr() */
 573	nilfs_segbuf_add_file_buffer(segbuf, bh);
 574	sci->sc_blk_cnt++;
 575 failed:
 576	return err;
 577}
 578
 579/*
 580 * Callback functions that enumerate, mark, and collect dirty blocks
 581 */
 582static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
 583				   struct buffer_head *bh, struct inode *inode)
 584{
 585	int err;
 586
 587	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 588	if (err < 0)
 589		return err;
 590
 591	err = nilfs_segctor_add_file_block(sci, bh, inode,
 592					   sizeof(struct nilfs_binfo_v));
 593	if (!err)
 594		sci->sc_datablk_cnt++;
 595	return err;
 596}
 597
 598static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
 599				   struct buffer_head *bh,
 600				   struct inode *inode)
 601{
 602	return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 603}
 604
 605static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
 606				   struct buffer_head *bh,
 607				   struct inode *inode)
 608{
 609	WARN_ON(!buffer_dirty(bh));
 610	return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 611}
 612
 613static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
 614					struct nilfs_segsum_pointer *ssp,
 615					union nilfs_binfo *binfo)
 616{
 617	struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
 618		sci, ssp, sizeof(*binfo_v));
 619	*binfo_v = binfo->bi_v;
 620}
 621
 622static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
 623					struct nilfs_segsum_pointer *ssp,
 624					union nilfs_binfo *binfo)
 625{
 626	__le64 *vblocknr = nilfs_segctor_map_segsum_entry(
 627		sci, ssp, sizeof(*vblocknr));
 628	*vblocknr = binfo->bi_v.bi_vblocknr;
 629}
 630
 631static const struct nilfs_sc_operations nilfs_sc_file_ops = {
 632	.collect_data = nilfs_collect_file_data,
 633	.collect_node = nilfs_collect_file_node,
 634	.collect_bmap = nilfs_collect_file_bmap,
 635	.write_data_binfo = nilfs_write_file_data_binfo,
 636	.write_node_binfo = nilfs_write_file_node_binfo,
 637};
 638
 639static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
 640				  struct buffer_head *bh, struct inode *inode)
 641{
 642	int err;
 643
 644	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 645	if (err < 0)
 646		return err;
 647
 648	err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 649	if (!err)
 650		sci->sc_datablk_cnt++;
 651	return err;
 652}
 653
 654static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
 655				  struct buffer_head *bh, struct inode *inode)
 656{
 657	WARN_ON(!buffer_dirty(bh));
 658	return nilfs_segctor_add_file_block(sci, bh, inode,
 659					    sizeof(struct nilfs_binfo_dat));
 660}
 661
 662static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
 663				       struct nilfs_segsum_pointer *ssp,
 664				       union nilfs_binfo *binfo)
 665{
 666	__le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
 667							  sizeof(*blkoff));
 668	*blkoff = binfo->bi_dat.bi_blkoff;
 669}
 670
 671static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
 672				       struct nilfs_segsum_pointer *ssp,
 673				       union nilfs_binfo *binfo)
 674{
 675	struct nilfs_binfo_dat *binfo_dat =
 676		nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
 677	*binfo_dat = binfo->bi_dat;
 678}
 679
 680static const struct nilfs_sc_operations nilfs_sc_dat_ops = {
 681	.collect_data = nilfs_collect_dat_data,
 682	.collect_node = nilfs_collect_file_node,
 683	.collect_bmap = nilfs_collect_dat_bmap,
 684	.write_data_binfo = nilfs_write_dat_data_binfo,
 685	.write_node_binfo = nilfs_write_dat_node_binfo,
 686};
 687
 688static const struct nilfs_sc_operations nilfs_sc_dsync_ops = {
 689	.collect_data = nilfs_collect_file_data,
 690	.collect_node = NULL,
 691	.collect_bmap = NULL,
 692	.write_data_binfo = nilfs_write_file_data_binfo,
 693	.write_node_binfo = NULL,
 694};
 695
 696static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
 697					      struct list_head *listp,
 698					      size_t nlimit,
 699					      loff_t start, loff_t end)
 700{
 701	struct address_space *mapping = inode->i_mapping;
 702	struct folio_batch fbatch;
 703	pgoff_t index = 0, last = ULONG_MAX;
 704	size_t ndirties = 0;
 705	int i;
 706
 707	if (unlikely(start != 0 || end != LLONG_MAX)) {
 708		/*
 709		 * A valid range is given for sync-ing data pages. The
 710		 * range is rounded to per-page; extra dirty buffers
 711		 * may be included if blocksize < pagesize.
 712		 */
 713		index = start >> PAGE_SHIFT;
 714		last = end >> PAGE_SHIFT;
 715	}
 716	folio_batch_init(&fbatch);
 717 repeat:
 718	if (unlikely(index > last) ||
 719	      !filemap_get_folios_tag(mapping, &index, last,
 720		      PAGECACHE_TAG_DIRTY, &fbatch))
 721		return ndirties;
 722
 723	for (i = 0; i < folio_batch_count(&fbatch); i++) {
 724		struct buffer_head *bh, *head;
 725		struct folio *folio = fbatch.folios[i];
 726
 727		folio_lock(folio);
 728		if (unlikely(folio->mapping != mapping)) {
 729			/* Exclude folios removed from the address space */
 730			folio_unlock(folio);
 731			continue;
 732		}
 733		head = folio_buffers(folio);
 734		if (!head)
 735			head = create_empty_buffers(folio,
 736					i_blocksize(inode), 0);
 737		folio_unlock(folio);
 738
 739		bh = head;
 740		do {
 741			if (!buffer_dirty(bh) || buffer_async_write(bh))
 742				continue;
 743			get_bh(bh);
 744			list_add_tail(&bh->b_assoc_buffers, listp);
 745			ndirties++;
 746			if (unlikely(ndirties >= nlimit)) {
 
 747				folio_batch_release(&fbatch);
 748				cond_resched();
 749				return ndirties;
 750			}
 751		} while (bh = bh->b_this_page, bh != head);
 
 
 752	}
 753	folio_batch_release(&fbatch);
 754	cond_resched();
 755	goto repeat;
 756}
 757
 758static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
 759					    struct list_head *listp)
 760{
 761	struct nilfs_inode_info *ii = NILFS_I(inode);
 762	struct inode *btnc_inode = ii->i_assoc_inode;
 763	struct folio_batch fbatch;
 764	struct buffer_head *bh, *head;
 765	unsigned int i;
 766	pgoff_t index = 0;
 767
 768	if (!btnc_inode)
 769		return;
 770	folio_batch_init(&fbatch);
 771
 772	while (filemap_get_folios_tag(btnc_inode->i_mapping, &index,
 773				(pgoff_t)-1, PAGECACHE_TAG_DIRTY, &fbatch)) {
 774		for (i = 0; i < folio_batch_count(&fbatch); i++) {
 775			bh = head = folio_buffers(fbatch.folios[i]);
 776			do {
 777				if (buffer_dirty(bh) &&
 778						!buffer_async_write(bh)) {
 779					get_bh(bh);
 780					list_add_tail(&bh->b_assoc_buffers,
 781						      listp);
 782				}
 783				bh = bh->b_this_page;
 784			} while (bh != head);
 785		}
 786		folio_batch_release(&fbatch);
 787		cond_resched();
 788	}
 789}
 790
 791static void nilfs_dispose_list(struct the_nilfs *nilfs,
 792			       struct list_head *head, int force)
 793{
 794	struct nilfs_inode_info *ii, *n;
 795	struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
 796	unsigned int nv = 0;
 797
 798	while (!list_empty(head)) {
 799		spin_lock(&nilfs->ns_inode_lock);
 800		list_for_each_entry_safe(ii, n, head, i_dirty) {
 801			list_del_init(&ii->i_dirty);
 802			if (force) {
 803				if (unlikely(ii->i_bh)) {
 804					brelse(ii->i_bh);
 805					ii->i_bh = NULL;
 806				}
 807			} else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
 808				set_bit(NILFS_I_QUEUED, &ii->i_state);
 809				list_add_tail(&ii->i_dirty,
 810					      &nilfs->ns_dirty_files);
 811				continue;
 812			}
 813			ivec[nv++] = ii;
 814			if (nv == SC_N_INODEVEC)
 815				break;
 816		}
 817		spin_unlock(&nilfs->ns_inode_lock);
 818
 819		for (pii = ivec; nv > 0; pii++, nv--)
 820			iput(&(*pii)->vfs_inode);
 821	}
 822}
 823
 824static void nilfs_iput_work_func(struct work_struct *work)
 825{
 826	struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
 827						 sc_iput_work);
 828	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 829
 830	nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
 831}
 832
 833static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
 834				     struct nilfs_root *root)
 835{
 836	int ret = 0;
 837
 838	if (nilfs_mdt_fetch_dirty(root->ifile))
 839		ret++;
 840	if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
 841		ret++;
 842	if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
 843		ret++;
 844	if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
 845		ret++;
 846	return ret;
 847}
 848
 849static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
 850{
 851	return list_empty(&sci->sc_dirty_files) &&
 852		!test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
 853		sci->sc_nfreesegs == 0 &&
 854		(!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
 855}
 856
 857static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
 858{
 859	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 860	int ret = 0;
 861
 862	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
 863		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
 864
 865	spin_lock(&nilfs->ns_inode_lock);
 866	if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
 867		ret++;
 868
 869	spin_unlock(&nilfs->ns_inode_lock);
 870	return ret;
 871}
 872
 873static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
 874{
 875	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 876
 877	nilfs_mdt_clear_dirty(sci->sc_root->ifile);
 878	nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
 879	nilfs_mdt_clear_dirty(nilfs->ns_sufile);
 880	nilfs_mdt_clear_dirty(nilfs->ns_dat);
 881}
 882
 883static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
 884{
 885	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 886	struct buffer_head *bh_cp;
 887	struct nilfs_checkpoint *raw_cp;
 888	int err;
 889
 890	/* XXX: this interface will be changed */
 891	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
 892					  &raw_cp, &bh_cp);
 893	if (likely(!err)) {
 894		/*
 895		 * The following code is duplicated with cpfile.  But, it is
 896		 * needed to collect the checkpoint even if it was not newly
 897		 * created.
 898		 */
 899		mark_buffer_dirty(bh_cp);
 900		nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
 901		nilfs_cpfile_put_checkpoint(
 902			nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
 903	} else if (err == -EINVAL || err == -ENOENT) {
 904		nilfs_error(sci->sc_super,
 905			    "checkpoint creation failed due to metadata corruption.");
 906		err = -EIO;
 907	}
 908	return err;
 909}
 910
 911static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 912{
 913	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 914	struct buffer_head *bh_cp;
 915	struct nilfs_checkpoint *raw_cp;
 916	int err;
 917
 918	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
 919					  &raw_cp, &bh_cp);
 920	if (unlikely(err)) {
 921		if (err == -EINVAL || err == -ENOENT) {
 922			nilfs_error(sci->sc_super,
 923				    "checkpoint finalization failed due to metadata corruption.");
 924			err = -EIO;
 925		}
 926		goto failed_ibh;
 927	}
 928	raw_cp->cp_snapshot_list.ssl_next = 0;
 929	raw_cp->cp_snapshot_list.ssl_prev = 0;
 930	raw_cp->cp_inodes_count =
 931		cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count));
 932	raw_cp->cp_blocks_count =
 933		cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count));
 934	raw_cp->cp_nblk_inc =
 935		cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
 936	raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
 937	raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
 938
 939	if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
 940		nilfs_checkpoint_clear_minor(raw_cp);
 941	else
 942		nilfs_checkpoint_set_minor(raw_cp);
 943
 944	nilfs_write_inode_common(sci->sc_root->ifile,
 945				 &raw_cp->cp_ifile_inode, 1);
 946	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
 947	return 0;
 948
 949 failed_ibh:
 950	return err;
 951}
 952
 953static void nilfs_fill_in_file_bmap(struct inode *ifile,
 954				    struct nilfs_inode_info *ii)
 955
 956{
 957	struct buffer_head *ibh;
 958	struct nilfs_inode *raw_inode;
 959
 960	if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
 961		ibh = ii->i_bh;
 962		BUG_ON(!ibh);
 963		raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
 964						  ibh);
 965		nilfs_bmap_write(ii->i_bmap, raw_inode);
 966		nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
 967	}
 968}
 969
 970static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
 971{
 972	struct nilfs_inode_info *ii;
 973
 974	list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
 975		nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
 976		set_bit(NILFS_I_COLLECTED, &ii->i_state);
 977	}
 978}
 979
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 980static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 981					     struct the_nilfs *nilfs)
 982{
 983	struct buffer_head *bh_sr;
 984	struct nilfs_super_root *raw_sr;
 985	unsigned int isz, srsz;
 986
 987	bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
 988
 989	lock_buffer(bh_sr);
 990	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
 991	isz = nilfs->ns_inode_size;
 992	srsz = NILFS_SR_BYTES(isz);
 993
 994	raw_sr->sr_sum = 0;  /* Ensure initialization within this update */
 995	raw_sr->sr_bytes = cpu_to_le16(srsz);
 996	raw_sr->sr_nongc_ctime
 997		= cpu_to_le64(nilfs_doing_gc() ?
 998			      nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
 999	raw_sr->sr_flags = 0;
1000
1001	nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
1002				 NILFS_SR_DAT_OFFSET(isz), 1);
1003	nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
1004				 NILFS_SR_CPFILE_OFFSET(isz), 1);
1005	nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
1006				 NILFS_SR_SUFILE_OFFSET(isz), 1);
 
1007	memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
1008	set_buffer_uptodate(bh_sr);
1009	unlock_buffer(bh_sr);
1010}
1011
1012static void nilfs_redirty_inodes(struct list_head *head)
1013{
1014	struct nilfs_inode_info *ii;
1015
1016	list_for_each_entry(ii, head, i_dirty) {
1017		if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
1018			clear_bit(NILFS_I_COLLECTED, &ii->i_state);
1019	}
1020}
1021
1022static void nilfs_drop_collected_inodes(struct list_head *head)
1023{
1024	struct nilfs_inode_info *ii;
1025
1026	list_for_each_entry(ii, head, i_dirty) {
1027		if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
1028			continue;
1029
1030		clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
1031		set_bit(NILFS_I_UPDATED, &ii->i_state);
1032	}
1033}
1034
1035static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
1036				       struct inode *inode,
1037				       struct list_head *listp,
1038				       int (*collect)(struct nilfs_sc_info *,
1039						      struct buffer_head *,
1040						      struct inode *))
1041{
1042	struct buffer_head *bh, *n;
1043	int err = 0;
1044
1045	if (collect) {
1046		list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1047			list_del_init(&bh->b_assoc_buffers);
1048			err = collect(sci, bh, inode);
1049			brelse(bh);
1050			if (unlikely(err))
1051				goto dispose_buffers;
1052		}
1053		return 0;
1054	}
1055
1056 dispose_buffers:
1057	while (!list_empty(listp)) {
1058		bh = list_first_entry(listp, struct buffer_head,
1059				      b_assoc_buffers);
1060		list_del_init(&bh->b_assoc_buffers);
1061		brelse(bh);
1062	}
1063	return err;
1064}
1065
1066static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1067{
1068	/* Remaining number of blocks within segment buffer */
1069	return sci->sc_segbuf_nblocks -
1070		(sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1071}
1072
1073static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1074				   struct inode *inode,
1075				   const struct nilfs_sc_operations *sc_ops)
1076{
1077	LIST_HEAD(data_buffers);
1078	LIST_HEAD(node_buffers);
1079	int err;
1080
1081	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1082		size_t n, rest = nilfs_segctor_buffer_rest(sci);
1083
1084		n = nilfs_lookup_dirty_data_buffers(
1085			inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1086		if (n > rest) {
1087			err = nilfs_segctor_apply_buffers(
1088				sci, inode, &data_buffers,
1089				sc_ops->collect_data);
1090			BUG_ON(!err); /* always receive -E2BIG or true error */
1091			goto break_or_fail;
1092		}
1093	}
1094	nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1095
1096	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1097		err = nilfs_segctor_apply_buffers(
1098			sci, inode, &data_buffers, sc_ops->collect_data);
1099		if (unlikely(err)) {
1100			/* dispose node list */
1101			nilfs_segctor_apply_buffers(
1102				sci, inode, &node_buffers, NULL);
1103			goto break_or_fail;
1104		}
1105		sci->sc_stage.flags |= NILFS_CF_NODE;
1106	}
1107	/* Collect node */
1108	err = nilfs_segctor_apply_buffers(
1109		sci, inode, &node_buffers, sc_ops->collect_node);
1110	if (unlikely(err))
1111		goto break_or_fail;
1112
1113	nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1114	err = nilfs_segctor_apply_buffers(
1115		sci, inode, &node_buffers, sc_ops->collect_bmap);
1116	if (unlikely(err))
1117		goto break_or_fail;
1118
1119	nilfs_segctor_end_finfo(sci, inode);
1120	sci->sc_stage.flags &= ~NILFS_CF_NODE;
1121
1122 break_or_fail:
1123	return err;
1124}
1125
1126static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1127					 struct inode *inode)
1128{
1129	LIST_HEAD(data_buffers);
1130	size_t n, rest = nilfs_segctor_buffer_rest(sci);
1131	int err;
1132
1133	n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1134					    sci->sc_dsync_start,
1135					    sci->sc_dsync_end);
1136
1137	err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1138					  nilfs_collect_file_data);
1139	if (!err) {
1140		nilfs_segctor_end_finfo(sci, inode);
1141		BUG_ON(n > rest);
1142		/* always receive -E2BIG or true error if n > rest */
1143	}
1144	return err;
1145}
1146
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1147static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1148{
1149	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1150	struct list_head *head;
1151	struct nilfs_inode_info *ii;
1152	size_t ndone;
1153	int err = 0;
1154
1155	switch (nilfs_sc_cstage_get(sci)) {
1156	case NILFS_ST_INIT:
1157		/* Pre-processes */
1158		sci->sc_stage.flags = 0;
1159
1160		if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1161			sci->sc_nblk_inc = 0;
1162			sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1163			if (mode == SC_LSEG_DSYNC) {
1164				nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
1165				goto dsync_mode;
1166			}
1167		}
1168
1169		sci->sc_stage.dirty_file_ptr = NULL;
1170		sci->sc_stage.gc_inode_ptr = NULL;
1171		if (mode == SC_FLUSH_DAT) {
1172			nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
1173			goto dat_stage;
1174		}
1175		nilfs_sc_cstage_inc(sci);
1176		fallthrough;
1177	case NILFS_ST_GC:
1178		if (nilfs_doing_gc()) {
1179			head = &sci->sc_gc_inodes;
1180			ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1181						head, i_dirty);
1182			list_for_each_entry_continue(ii, head, i_dirty) {
1183				err = nilfs_segctor_scan_file(
1184					sci, &ii->vfs_inode,
1185					&nilfs_sc_file_ops);
1186				if (unlikely(err)) {
1187					sci->sc_stage.gc_inode_ptr = list_entry(
1188						ii->i_dirty.prev,
1189						struct nilfs_inode_info,
1190						i_dirty);
1191					goto break_or_fail;
1192				}
1193				set_bit(NILFS_I_COLLECTED, &ii->i_state);
1194			}
1195			sci->sc_stage.gc_inode_ptr = NULL;
1196		}
1197		nilfs_sc_cstage_inc(sci);
1198		fallthrough;
1199	case NILFS_ST_FILE:
1200		head = &sci->sc_dirty_files;
1201		ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1202					i_dirty);
1203		list_for_each_entry_continue(ii, head, i_dirty) {
1204			clear_bit(NILFS_I_DIRTY, &ii->i_state);
1205
1206			err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1207						      &nilfs_sc_file_ops);
1208			if (unlikely(err)) {
1209				sci->sc_stage.dirty_file_ptr =
1210					list_entry(ii->i_dirty.prev,
1211						   struct nilfs_inode_info,
1212						   i_dirty);
1213				goto break_or_fail;
1214			}
1215			/* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1216			/* XXX: required ? */
1217		}
1218		sci->sc_stage.dirty_file_ptr = NULL;
1219		if (mode == SC_FLUSH_FILE) {
1220			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1221			return 0;
1222		}
1223		nilfs_sc_cstage_inc(sci);
1224		sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1225		fallthrough;
1226	case NILFS_ST_IFILE:
1227		err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1228					      &nilfs_sc_file_ops);
1229		if (unlikely(err))
1230			break;
1231		nilfs_sc_cstage_inc(sci);
1232		/* Creating a checkpoint */
1233		err = nilfs_segctor_create_checkpoint(sci);
 
1234		if (unlikely(err))
1235			break;
1236		fallthrough;
1237	case NILFS_ST_CPFILE:
1238		err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1239					      &nilfs_sc_file_ops);
1240		if (unlikely(err))
1241			break;
1242		nilfs_sc_cstage_inc(sci);
1243		fallthrough;
1244	case NILFS_ST_SUFILE:
1245		err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1246					 sci->sc_nfreesegs, &ndone);
1247		if (unlikely(err)) {
1248			nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1249						  sci->sc_freesegs, ndone,
1250						  NULL);
1251			break;
1252		}
1253		sci->sc_stage.flags |= NILFS_CF_SUFREED;
1254
1255		err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1256					      &nilfs_sc_file_ops);
1257		if (unlikely(err))
1258			break;
1259		nilfs_sc_cstage_inc(sci);
1260		fallthrough;
1261	case NILFS_ST_DAT:
1262 dat_stage:
1263		err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1264					      &nilfs_sc_dat_ops);
1265		if (unlikely(err))
1266			break;
1267		if (mode == SC_FLUSH_DAT) {
1268			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1269			return 0;
1270		}
1271		nilfs_sc_cstage_inc(sci);
1272		fallthrough;
1273	case NILFS_ST_SR:
1274		if (mode == SC_LSEG_SR) {
1275			/* Appending a super root */
1276			err = nilfs_segctor_add_super_root(sci);
1277			if (unlikely(err))
1278				break;
1279		}
1280		/* End of a logical segment */
1281		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1282		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1283		return 0;
1284	case NILFS_ST_DSYNC:
1285 dsync_mode:
1286		sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1287		ii = sci->sc_dsync_inode;
1288		if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1289			break;
1290
1291		err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1292		if (unlikely(err))
1293			break;
1294		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1295		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1296		return 0;
1297	case NILFS_ST_DONE:
1298		return 0;
1299	default:
1300		BUG();
1301	}
1302
1303 break_or_fail:
1304	return err;
1305}
1306
1307/**
1308 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1309 * @sci: nilfs_sc_info
1310 * @nilfs: nilfs object
1311 */
1312static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1313					    struct the_nilfs *nilfs)
1314{
1315	struct nilfs_segment_buffer *segbuf, *prev;
1316	__u64 nextnum;
1317	int err, alloc = 0;
1318
1319	segbuf = nilfs_segbuf_new(sci->sc_super);
1320	if (unlikely(!segbuf))
1321		return -ENOMEM;
1322
1323	if (list_empty(&sci->sc_write_logs)) {
1324		nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1325				 nilfs->ns_pseg_offset, nilfs);
1326		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1327			nilfs_shift_to_next_segment(nilfs);
1328			nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1329		}
1330
1331		segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1332		nextnum = nilfs->ns_nextnum;
1333
1334		if (nilfs->ns_segnum == nilfs->ns_nextnum)
1335			/* Start from the head of a new full segment */
1336			alloc++;
1337	} else {
1338		/* Continue logs */
1339		prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1340		nilfs_segbuf_map_cont(segbuf, prev);
1341		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1342		nextnum = prev->sb_nextnum;
1343
1344		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1345			nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1346			segbuf->sb_sum.seg_seq++;
1347			alloc++;
1348		}
1349	}
1350
1351	err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1352	if (err)
1353		goto failed;
1354
1355	if (alloc) {
1356		err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1357		if (err)
1358			goto failed;
1359	}
1360	nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1361
1362	BUG_ON(!list_empty(&sci->sc_segbufs));
1363	list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1364	sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1365	return 0;
1366
1367 failed:
1368	nilfs_segbuf_free(segbuf);
1369	return err;
1370}
1371
1372static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1373					 struct the_nilfs *nilfs, int nadd)
1374{
1375	struct nilfs_segment_buffer *segbuf, *prev;
1376	struct inode *sufile = nilfs->ns_sufile;
1377	__u64 nextnextnum;
1378	LIST_HEAD(list);
1379	int err, ret, i;
1380
1381	prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1382	/*
1383	 * Since the segment specified with nextnum might be allocated during
1384	 * the previous construction, the buffer including its segusage may
1385	 * not be dirty.  The following call ensures that the buffer is dirty
1386	 * and will pin the buffer on memory until the sufile is written.
1387	 */
1388	err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1389	if (unlikely(err))
1390		return err;
1391
1392	for (i = 0; i < nadd; i++) {
1393		/* extend segment info */
1394		err = -ENOMEM;
1395		segbuf = nilfs_segbuf_new(sci->sc_super);
1396		if (unlikely(!segbuf))
1397			goto failed;
1398
1399		/* map this buffer to region of segment on-disk */
1400		nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1401		sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1402
1403		/* allocate the next next full segment */
1404		err = nilfs_sufile_alloc(sufile, &nextnextnum);
1405		if (unlikely(err))
1406			goto failed_segbuf;
1407
1408		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1409		nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1410
1411		list_add_tail(&segbuf->sb_list, &list);
1412		prev = segbuf;
1413	}
1414	list_splice_tail(&list, &sci->sc_segbufs);
1415	return 0;
1416
1417 failed_segbuf:
1418	nilfs_segbuf_free(segbuf);
1419 failed:
1420	list_for_each_entry(segbuf, &list, sb_list) {
1421		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1422		WARN_ON(ret); /* never fails */
1423	}
1424	nilfs_destroy_logs(&list);
1425	return err;
1426}
1427
1428static void nilfs_free_incomplete_logs(struct list_head *logs,
1429				       struct the_nilfs *nilfs)
1430{
1431	struct nilfs_segment_buffer *segbuf, *prev;
1432	struct inode *sufile = nilfs->ns_sufile;
1433	int ret;
1434
1435	segbuf = NILFS_FIRST_SEGBUF(logs);
1436	if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1437		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1438		WARN_ON(ret); /* never fails */
1439	}
1440	if (atomic_read(&segbuf->sb_err)) {
1441		/* Case 1: The first segment failed */
1442		if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1443			/*
1444			 * Case 1a:  Partial segment appended into an existing
1445			 * segment
1446			 */
1447			nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1448						segbuf->sb_fseg_end);
1449		else /* Case 1b:  New full segment */
1450			set_nilfs_discontinued(nilfs);
1451	}
1452
1453	prev = segbuf;
1454	list_for_each_entry_continue(segbuf, logs, sb_list) {
1455		if (prev->sb_nextnum != segbuf->sb_nextnum) {
1456			ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1457			WARN_ON(ret); /* never fails */
1458		}
1459		if (atomic_read(&segbuf->sb_err) &&
1460		    segbuf->sb_segnum != nilfs->ns_nextnum)
1461			/* Case 2: extended segment (!= next) failed */
1462			nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1463		prev = segbuf;
1464	}
1465}
1466
1467static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1468					  struct inode *sufile)
1469{
1470	struct nilfs_segment_buffer *segbuf;
1471	unsigned long live_blocks;
1472	int ret;
1473
1474	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1475		live_blocks = segbuf->sb_sum.nblocks +
1476			(segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1477		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1478						     live_blocks,
1479						     sci->sc_seg_ctime);
1480		WARN_ON(ret); /* always succeed because the segusage is dirty */
1481	}
1482}
1483
1484static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1485{
1486	struct nilfs_segment_buffer *segbuf;
1487	int ret;
1488
1489	segbuf = NILFS_FIRST_SEGBUF(logs);
1490	ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1491					     segbuf->sb_pseg_start -
1492					     segbuf->sb_fseg_start, 0);
1493	WARN_ON(ret); /* always succeed because the segusage is dirty */
1494
1495	list_for_each_entry_continue(segbuf, logs, sb_list) {
1496		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1497						     0, 0);
1498		WARN_ON(ret); /* always succeed */
1499	}
1500}
1501
1502static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1503					    struct nilfs_segment_buffer *last,
1504					    struct inode *sufile)
1505{
1506	struct nilfs_segment_buffer *segbuf = last;
1507	int ret;
1508
1509	list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1510		sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1511		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1512		WARN_ON(ret);
1513	}
1514	nilfs_truncate_logs(&sci->sc_segbufs, last);
1515}
1516
1517
1518static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1519				 struct the_nilfs *nilfs, int mode)
1520{
1521	struct nilfs_cstage prev_stage = sci->sc_stage;
1522	int err, nadd = 1;
1523
1524	/* Collection retry loop */
1525	for (;;) {
1526		sci->sc_nblk_this_inc = 0;
1527		sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1528
1529		err = nilfs_segctor_reset_segment_buffer(sci);
1530		if (unlikely(err))
1531			goto failed;
1532
1533		err = nilfs_segctor_collect_blocks(sci, mode);
1534		sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1535		if (!err)
1536			break;
1537
1538		if (unlikely(err != -E2BIG))
1539			goto failed;
1540
1541		/* The current segment is filled up */
1542		if (mode != SC_LSEG_SR ||
1543		    nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
1544			break;
1545
1546		nilfs_clear_logs(&sci->sc_segbufs);
1547
1548		if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1549			err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1550							sci->sc_freesegs,
1551							sci->sc_nfreesegs,
1552							NULL);
1553			WARN_ON(err); /* do not happen */
1554			sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1555		}
1556
1557		err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1558		if (unlikely(err))
1559			return err;
1560
1561		nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1562		sci->sc_stage = prev_stage;
1563	}
1564	nilfs_segctor_zeropad_segsum(sci);
1565	nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1566	return 0;
1567
1568 failed:
1569	return err;
1570}
1571
1572static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1573				      struct buffer_head *new_bh)
1574{
1575	BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1576
1577	list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1578	/* The caller must release old_bh */
1579}
1580
1581static int
1582nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1583				     struct nilfs_segment_buffer *segbuf,
1584				     int mode)
1585{
1586	struct inode *inode = NULL;
1587	sector_t blocknr;
1588	unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1589	unsigned long nblocks = 0, ndatablk = 0;
1590	const struct nilfs_sc_operations *sc_op = NULL;
1591	struct nilfs_segsum_pointer ssp;
1592	struct nilfs_finfo *finfo = NULL;
1593	union nilfs_binfo binfo;
1594	struct buffer_head *bh, *bh_org;
1595	ino_t ino = 0;
1596	int err = 0;
1597
1598	if (!nfinfo)
1599		goto out;
1600
1601	blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1602	ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1603	ssp.offset = sizeof(struct nilfs_segment_summary);
1604
1605	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1606		if (bh == segbuf->sb_super_root)
1607			break;
1608		if (!finfo) {
1609			finfo =	nilfs_segctor_map_segsum_entry(
1610				sci, &ssp, sizeof(*finfo));
1611			ino = le64_to_cpu(finfo->fi_ino);
1612			nblocks = le32_to_cpu(finfo->fi_nblocks);
1613			ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1614
1615			inode = bh->b_folio->mapping->host;
1616
1617			if (mode == SC_LSEG_DSYNC)
1618				sc_op = &nilfs_sc_dsync_ops;
1619			else if (ino == NILFS_DAT_INO)
1620				sc_op = &nilfs_sc_dat_ops;
1621			else /* file blocks */
1622				sc_op = &nilfs_sc_file_ops;
1623		}
1624		bh_org = bh;
1625		get_bh(bh_org);
1626		err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1627					&binfo);
1628		if (bh != bh_org)
1629			nilfs_list_replace_buffer(bh_org, bh);
1630		brelse(bh_org);
1631		if (unlikely(err))
1632			goto failed_bmap;
1633
1634		if (ndatablk > 0)
1635			sc_op->write_data_binfo(sci, &ssp, &binfo);
1636		else
1637			sc_op->write_node_binfo(sci, &ssp, &binfo);
1638
1639		blocknr++;
1640		if (--nblocks == 0) {
1641			finfo = NULL;
1642			if (--nfinfo == 0)
1643				break;
1644		} else if (ndatablk > 0)
1645			ndatablk--;
1646	}
1647 out:
1648	return 0;
1649
1650 failed_bmap:
1651	return err;
1652}
1653
1654static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1655{
1656	struct nilfs_segment_buffer *segbuf;
1657	int err;
1658
1659	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1660		err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1661		if (unlikely(err))
1662			return err;
1663		nilfs_segbuf_fill_in_segsum(segbuf);
1664	}
1665	return 0;
1666}
1667
1668static void nilfs_begin_folio_io(struct folio *folio)
1669{
1670	if (!folio || folio_test_writeback(folio))
1671		/*
1672		 * For split b-tree node pages, this function may be called
1673		 * twice.  We ignore the 2nd or later calls by this check.
1674		 */
1675		return;
1676
1677	folio_lock(folio);
1678	folio_clear_dirty_for_io(folio);
1679	folio_start_writeback(folio);
1680	folio_unlock(folio);
1681}
1682
1683static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
 
 
 
 
 
 
 
 
 
 
 
 
1684{
1685	struct nilfs_segment_buffer *segbuf;
1686	struct folio *bd_folio = NULL, *fs_folio = NULL;
 
1687
1688	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1689		struct buffer_head *bh;
1690
1691		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1692				    b_assoc_buffers) {
1693			if (bh->b_folio != bd_folio) {
1694				if (bd_folio) {
1695					folio_lock(bd_folio);
1696					folio_clear_dirty_for_io(bd_folio);
1697					folio_start_writeback(bd_folio);
1698					folio_unlock(bd_folio);
1699				}
1700				bd_folio = bh->b_folio;
1701			}
1702		}
1703
1704		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1705				    b_assoc_buffers) {
1706			if (bh == segbuf->sb_super_root) {
1707				if (bh->b_folio != bd_folio) {
1708					folio_lock(bd_folio);
1709					folio_clear_dirty_for_io(bd_folio);
1710					folio_start_writeback(bd_folio);
1711					folio_unlock(bd_folio);
1712					bd_folio = bh->b_folio;
1713				}
1714				break;
1715			}
1716			set_buffer_async_write(bh);
1717			if (bh->b_folio != fs_folio) {
1718				nilfs_begin_folio_io(fs_folio);
1719				fs_folio = bh->b_folio;
1720			}
1721		}
1722	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1723	if (bd_folio) {
1724		folio_lock(bd_folio);
 
1725		folio_clear_dirty_for_io(bd_folio);
1726		folio_start_writeback(bd_folio);
1727		folio_unlock(bd_folio);
1728	}
1729	nilfs_begin_folio_io(fs_folio);
1730}
1731
1732static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1733			       struct the_nilfs *nilfs)
1734{
1735	int ret;
1736
1737	ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1738	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1739	return ret;
1740}
1741
1742static void nilfs_end_folio_io(struct folio *folio, int err)
1743{
1744	if (!folio)
1745		return;
1746
1747	if (buffer_nilfs_node(folio_buffers(folio)) &&
1748			!folio_test_writeback(folio)) {
1749		/*
1750		 * For b-tree node pages, this function may be called twice
1751		 * or more because they might be split in a segment.
1752		 */
1753		if (folio_test_dirty(folio)) {
1754			/*
1755			 * For pages holding split b-tree node buffers, dirty
1756			 * flag on the buffers may be cleared discretely.
1757			 * In that case, the page is once redirtied for
1758			 * remaining buffers, and it must be cancelled if
1759			 * all the buffers get cleaned later.
1760			 */
1761			folio_lock(folio);
1762			if (nilfs_folio_buffers_clean(folio))
1763				__nilfs_clear_folio_dirty(folio);
1764			folio_unlock(folio);
1765		}
1766		return;
1767	}
1768
1769	if (!err) {
1770		if (!nilfs_folio_buffers_clean(folio))
1771			filemap_dirty_folio(folio->mapping, folio);
1772		folio_clear_error(folio);
1773	} else {
1774		filemap_dirty_folio(folio->mapping, folio);
1775		folio_set_error(folio);
1776	}
1777
1778	folio_end_writeback(folio);
1779}
1780
1781static void nilfs_abort_logs(struct list_head *logs, int err)
1782{
1783	struct nilfs_segment_buffer *segbuf;
1784	struct folio *bd_folio = NULL, *fs_folio = NULL;
1785	struct buffer_head *bh;
1786
1787	if (list_empty(logs))
1788		return;
1789
1790	list_for_each_entry(segbuf, logs, sb_list) {
1791		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1792				    b_assoc_buffers) {
1793			clear_buffer_uptodate(bh);
1794			if (bh->b_folio != bd_folio) {
1795				if (bd_folio)
1796					folio_end_writeback(bd_folio);
1797				bd_folio = bh->b_folio;
1798			}
1799		}
1800
1801		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1802				    b_assoc_buffers) {
1803			if (bh == segbuf->sb_super_root) {
1804				clear_buffer_uptodate(bh);
1805				if (bh->b_folio != bd_folio) {
1806					folio_end_writeback(bd_folio);
1807					bd_folio = bh->b_folio;
1808				}
1809				break;
1810			}
1811			clear_buffer_async_write(bh);
1812			if (bh->b_folio != fs_folio) {
1813				nilfs_end_folio_io(fs_folio, err);
1814				fs_folio = bh->b_folio;
1815			}
1816		}
1817	}
1818	if (bd_folio)
1819		folio_end_writeback(bd_folio);
1820
1821	nilfs_end_folio_io(fs_folio, err);
1822}
1823
1824static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1825					     struct the_nilfs *nilfs, int err)
1826{
1827	LIST_HEAD(logs);
1828	int ret;
1829
1830	list_splice_tail_init(&sci->sc_write_logs, &logs);
1831	ret = nilfs_wait_on_logs(&logs);
1832	nilfs_abort_logs(&logs, ret ? : err);
1833
1834	list_splice_tail_init(&sci->sc_segbufs, &logs);
 
 
 
1835	nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1836	nilfs_free_incomplete_logs(&logs, nilfs);
1837
1838	if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1839		ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1840						sci->sc_freesegs,
1841						sci->sc_nfreesegs,
1842						NULL);
1843		WARN_ON(ret); /* do not happen */
1844	}
1845
1846	nilfs_destroy_logs(&logs);
1847}
1848
1849static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1850				   struct nilfs_segment_buffer *segbuf)
1851{
1852	nilfs->ns_segnum = segbuf->sb_segnum;
1853	nilfs->ns_nextnum = segbuf->sb_nextnum;
1854	nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1855		+ segbuf->sb_sum.nblocks;
1856	nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1857	nilfs->ns_ctime = segbuf->sb_sum.ctime;
1858}
1859
1860static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1861{
1862	struct nilfs_segment_buffer *segbuf;
1863	struct folio *bd_folio = NULL, *fs_folio = NULL;
1864	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1865	int update_sr = false;
1866
1867	list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1868		struct buffer_head *bh;
1869
1870		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1871				    b_assoc_buffers) {
1872			set_buffer_uptodate(bh);
1873			clear_buffer_dirty(bh);
1874			if (bh->b_folio != bd_folio) {
1875				if (bd_folio)
1876					folio_end_writeback(bd_folio);
1877				bd_folio = bh->b_folio;
1878			}
1879		}
1880		/*
1881		 * We assume that the buffers which belong to the same folio
1882		 * continue over the buffer list.
1883		 * Under this assumption, the last BHs of folios is
1884		 * identifiable by the discontinuity of bh->b_folio
1885		 * (folio != fs_folio).
1886		 *
1887		 * For B-tree node blocks, however, this assumption is not
1888		 * guaranteed.  The cleanup code of B-tree node folios needs
1889		 * special care.
1890		 */
1891		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1892				    b_assoc_buffers) {
1893			const unsigned long set_bits = BIT(BH_Uptodate);
1894			const unsigned long clear_bits =
1895				(BIT(BH_Dirty) | BIT(BH_Async_Write) |
1896				 BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |
1897				 BIT(BH_NILFS_Redirected));
1898
1899			if (bh == segbuf->sb_super_root) {
1900				set_buffer_uptodate(bh);
1901				clear_buffer_dirty(bh);
1902				if (bh->b_folio != bd_folio) {
1903					folio_end_writeback(bd_folio);
1904					bd_folio = bh->b_folio;
1905				}
1906				update_sr = true;
1907				break;
1908			}
1909			set_mask_bits(&bh->b_state, clear_bits, set_bits);
1910			if (bh->b_folio != fs_folio) {
1911				nilfs_end_folio_io(fs_folio, 0);
1912				fs_folio = bh->b_folio;
1913			}
1914		}
1915
1916		if (!nilfs_segbuf_simplex(segbuf)) {
1917			if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1918				set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1919				sci->sc_lseg_stime = jiffies;
1920			}
1921			if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1922				clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1923		}
1924	}
1925	/*
1926	 * Since folios may continue over multiple segment buffers,
1927	 * end of the last folio must be checked outside of the loop.
1928	 */
1929	if (bd_folio)
1930		folio_end_writeback(bd_folio);
1931
1932	nilfs_end_folio_io(fs_folio, 0);
1933
1934	nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1935
1936	if (nilfs_doing_gc())
1937		nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1938	else
1939		nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1940
1941	sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1942
1943	segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1944	nilfs_set_next_segment(nilfs, segbuf);
1945
1946	if (update_sr) {
1947		nilfs->ns_flushed_device = 0;
1948		nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1949				       segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1950
1951		clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1952		clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1953		set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1954		nilfs_segctor_clear_metadata_dirty(sci);
1955	} else
1956		clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1957}
1958
1959static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1960{
1961	int ret;
1962
1963	ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1964	if (!ret) {
1965		nilfs_segctor_complete_write(sci);
1966		nilfs_destroy_logs(&sci->sc_write_logs);
1967	}
1968	return ret;
1969}
1970
1971static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1972					     struct the_nilfs *nilfs)
1973{
1974	struct nilfs_inode_info *ii, *n;
1975	struct inode *ifile = sci->sc_root->ifile;
1976
1977	spin_lock(&nilfs->ns_inode_lock);
1978 retry:
1979	list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1980		if (!ii->i_bh) {
1981			struct buffer_head *ibh;
1982			int err;
1983
1984			spin_unlock(&nilfs->ns_inode_lock);
1985			err = nilfs_ifile_get_inode_block(
1986				ifile, ii->vfs_inode.i_ino, &ibh);
1987			if (unlikely(err)) {
1988				nilfs_warn(sci->sc_super,
1989					   "log writer: error %d getting inode block (ino=%lu)",
1990					   err, ii->vfs_inode.i_ino);
1991				return err;
1992			}
1993			spin_lock(&nilfs->ns_inode_lock);
1994			if (likely(!ii->i_bh))
1995				ii->i_bh = ibh;
1996			else
1997				brelse(ibh);
1998			goto retry;
1999		}
2000
2001		// Always redirty the buffer to avoid race condition
2002		mark_buffer_dirty(ii->i_bh);
2003		nilfs_mdt_mark_dirty(ifile);
2004
2005		clear_bit(NILFS_I_QUEUED, &ii->i_state);
2006		set_bit(NILFS_I_BUSY, &ii->i_state);
2007		list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
2008	}
2009	spin_unlock(&nilfs->ns_inode_lock);
2010
2011	return 0;
2012}
2013
2014static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
2015					     struct the_nilfs *nilfs)
2016{
2017	struct nilfs_inode_info *ii, *n;
2018	int during_mount = !(sci->sc_super->s_flags & SB_ACTIVE);
2019	int defer_iput = false;
2020
2021	spin_lock(&nilfs->ns_inode_lock);
2022	list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2023		if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2024		    test_bit(NILFS_I_DIRTY, &ii->i_state))
2025			continue;
2026
2027		clear_bit(NILFS_I_BUSY, &ii->i_state);
2028		brelse(ii->i_bh);
2029		ii->i_bh = NULL;
2030		list_del_init(&ii->i_dirty);
2031		if (!ii->vfs_inode.i_nlink || during_mount) {
2032			/*
2033			 * Defer calling iput() to avoid deadlocks if
2034			 * i_nlink == 0 or mount is not yet finished.
2035			 */
2036			list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
2037			defer_iput = true;
2038		} else {
2039			spin_unlock(&nilfs->ns_inode_lock);
2040			iput(&ii->vfs_inode);
2041			spin_lock(&nilfs->ns_inode_lock);
2042		}
2043	}
2044	spin_unlock(&nilfs->ns_inode_lock);
2045
2046	if (defer_iput)
2047		schedule_work(&sci->sc_iput_work);
2048}
2049
2050/*
2051 * Main procedure of segment constructor
2052 */
2053static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2054{
2055	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2056	int err;
2057
2058	if (sb_rdonly(sci->sc_super))
2059		return -EROFS;
2060
2061	nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2062	sci->sc_cno = nilfs->ns_cno;
2063
2064	err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2065	if (unlikely(err))
2066		goto out;
2067
2068	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2069		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2070
2071	if (nilfs_segctor_clean(sci))
2072		goto out;
2073
2074	do {
2075		sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2076
2077		err = nilfs_segctor_begin_construction(sci, nilfs);
2078		if (unlikely(err))
2079			goto out;
2080
2081		/* Update time stamp */
2082		sci->sc_seg_ctime = ktime_get_real_seconds();
2083
2084		err = nilfs_segctor_collect(sci, nilfs, mode);
2085		if (unlikely(err))
2086			goto failed;
2087
2088		/* Avoid empty segment */
2089		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2090		    nilfs_segbuf_empty(sci->sc_curseg)) {
2091			nilfs_segctor_abort_construction(sci, nilfs, 1);
2092			goto out;
2093		}
2094
2095		err = nilfs_segctor_assign(sci, mode);
2096		if (unlikely(err))
2097			goto failed;
2098
2099		if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2100			nilfs_segctor_fill_in_file_bmap(sci);
2101
2102		if (mode == SC_LSEG_SR &&
2103		    nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2104			err = nilfs_segctor_fill_in_checkpoint(sci);
 
 
 
 
2105			if (unlikely(err))
2106				goto failed_to_write;
2107
2108			nilfs_segctor_fill_in_super_root(sci, nilfs);
2109		}
2110		nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2111
2112		/* Write partial segments */
2113		nilfs_segctor_prepare_write(sci);
2114
2115		nilfs_add_checksums_on_logs(&sci->sc_segbufs,
2116					    nilfs->ns_crc_seed);
2117
2118		err = nilfs_segctor_write(sci, nilfs);
2119		if (unlikely(err))
2120			goto failed_to_write;
2121
2122		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2123		    nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2124			/*
2125			 * At this point, we avoid double buffering
2126			 * for blocksize < pagesize because page dirty
2127			 * flag is turned off during write and dirty
2128			 * buffers are not properly collected for
2129			 * pages crossing over segments.
2130			 */
2131			err = nilfs_segctor_wait(sci);
2132			if (err)
2133				goto failed_to_write;
2134		}
2135	} while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2136
2137 out:
2138	nilfs_segctor_drop_written_files(sci, nilfs);
2139	return err;
2140
2141 failed_to_write:
2142	if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2143		nilfs_redirty_inodes(&sci->sc_dirty_files);
2144
2145 failed:
 
 
2146	if (nilfs_doing_gc())
2147		nilfs_redirty_inodes(&sci->sc_gc_inodes);
2148	nilfs_segctor_abort_construction(sci, nilfs, err);
2149	goto out;
2150}
2151
2152/**
2153 * nilfs_segctor_start_timer - set timer of background write
2154 * @sci: nilfs_sc_info
2155 *
2156 * If the timer has already been set, it ignores the new request.
2157 * This function MUST be called within a section locking the segment
2158 * semaphore.
2159 */
2160static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2161{
2162	spin_lock(&sci->sc_state_lock);
2163	if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2164		sci->sc_timer.expires = jiffies + sci->sc_interval;
2165		add_timer(&sci->sc_timer);
 
 
2166		sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2167	}
2168	spin_unlock(&sci->sc_state_lock);
2169}
2170
2171static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2172{
2173	spin_lock(&sci->sc_state_lock);
2174	if (!(sci->sc_flush_request & BIT(bn))) {
2175		unsigned long prev_req = sci->sc_flush_request;
2176
2177		sci->sc_flush_request |= BIT(bn);
2178		if (!prev_req)
2179			wake_up(&sci->sc_wait_daemon);
2180	}
2181	spin_unlock(&sci->sc_state_lock);
2182}
2183
2184/**
2185 * nilfs_flush_segment - trigger a segment construction for resource control
2186 * @sb: super block
2187 * @ino: inode number of the file to be flushed out.
2188 */
2189void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2190{
2191	struct the_nilfs *nilfs = sb->s_fs_info;
2192	struct nilfs_sc_info *sci = nilfs->ns_writer;
2193
2194	if (!sci || nilfs_doing_construction())
2195		return;
2196	nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2197					/* assign bit 0 to data files */
2198}
2199
2200struct nilfs_segctor_wait_request {
2201	wait_queue_entry_t	wq;
2202	__u32		seq;
2203	int		err;
2204	atomic_t	done;
2205};
2206
2207static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2208{
2209	struct nilfs_segctor_wait_request wait_req;
2210	int err = 0;
2211
2212	spin_lock(&sci->sc_state_lock);
2213	init_wait(&wait_req.wq);
2214	wait_req.err = 0;
2215	atomic_set(&wait_req.done, 0);
 
 
 
 
 
 
 
 
 
 
2216	wait_req.seq = ++sci->sc_seq_request;
 
2217	spin_unlock(&sci->sc_state_lock);
2218
2219	init_waitqueue_entry(&wait_req.wq, current);
2220	add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2221	set_current_state(TASK_INTERRUPTIBLE);
2222	wake_up(&sci->sc_wait_daemon);
2223
2224	for (;;) {
 
 
 
 
 
 
 
 
 
 
2225		if (atomic_read(&wait_req.done)) {
2226			err = wait_req.err;
2227			break;
2228		}
2229		if (!signal_pending(current)) {
2230			schedule();
2231			continue;
2232		}
2233		err = -ERESTARTSYS;
2234		break;
2235	}
2236	finish_wait(&sci->sc_wait_request, &wait_req.wq);
2237	return err;
2238}
2239
2240static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2241{
2242	struct nilfs_segctor_wait_request *wrq, *n;
2243	unsigned long flags;
2244
2245	spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2246	list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.head, wq.entry) {
2247		if (!atomic_read(&wrq->done) &&
2248		    nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2249			wrq->err = err;
2250			atomic_set(&wrq->done, 1);
2251		}
2252		if (atomic_read(&wrq->done)) {
2253			wrq->wq.func(&wrq->wq,
2254				     TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2255				     0, NULL);
2256		}
2257	}
2258	spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2259}
2260
2261/**
2262 * nilfs_construct_segment - construct a logical segment
2263 * @sb: super block
2264 *
2265 * Return Value: On success, 0 is returned. On errors, one of the following
2266 * negative error code is returned.
2267 *
2268 * %-EROFS - Read only filesystem.
2269 *
2270 * %-EIO - I/O error
2271 *
2272 * %-ENOSPC - No space left on device (only in a panic state).
2273 *
2274 * %-ERESTARTSYS - Interrupted.
2275 *
2276 * %-ENOMEM - Insufficient memory available.
2277 */
2278int nilfs_construct_segment(struct super_block *sb)
2279{
2280	struct the_nilfs *nilfs = sb->s_fs_info;
2281	struct nilfs_sc_info *sci = nilfs->ns_writer;
2282	struct nilfs_transaction_info *ti;
2283
2284	if (sb_rdonly(sb) || unlikely(!sci))
2285		return -EROFS;
2286
2287	/* A call inside transactions causes a deadlock. */
2288	BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2289
2290	return nilfs_segctor_sync(sci);
2291}
2292
2293/**
2294 * nilfs_construct_dsync_segment - construct a data-only logical segment
2295 * @sb: super block
2296 * @inode: inode whose data blocks should be written out
2297 * @start: start byte offset
2298 * @end: end byte offset (inclusive)
2299 *
2300 * Return Value: On success, 0 is returned. On errors, one of the following
2301 * negative error code is returned.
2302 *
2303 * %-EROFS - Read only filesystem.
2304 *
2305 * %-EIO - I/O error
2306 *
2307 * %-ENOSPC - No space left on device (only in a panic state).
2308 *
2309 * %-ERESTARTSYS - Interrupted.
2310 *
2311 * %-ENOMEM - Insufficient memory available.
2312 */
2313int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2314				  loff_t start, loff_t end)
2315{
2316	struct the_nilfs *nilfs = sb->s_fs_info;
2317	struct nilfs_sc_info *sci = nilfs->ns_writer;
2318	struct nilfs_inode_info *ii;
2319	struct nilfs_transaction_info ti;
2320	int err = 0;
2321
2322	if (sb_rdonly(sb) || unlikely(!sci))
2323		return -EROFS;
2324
2325	nilfs_transaction_lock(sb, &ti, 0);
2326
2327	ii = NILFS_I(inode);
2328	if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2329	    nilfs_test_opt(nilfs, STRICT_ORDER) ||
2330	    test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2331	    nilfs_discontinued(nilfs)) {
2332		nilfs_transaction_unlock(sb);
2333		err = nilfs_segctor_sync(sci);
2334		return err;
2335	}
2336
2337	spin_lock(&nilfs->ns_inode_lock);
2338	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2339	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2340		spin_unlock(&nilfs->ns_inode_lock);
2341		nilfs_transaction_unlock(sb);
2342		return 0;
2343	}
2344	spin_unlock(&nilfs->ns_inode_lock);
2345	sci->sc_dsync_inode = ii;
2346	sci->sc_dsync_start = start;
2347	sci->sc_dsync_end = end;
2348
2349	err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2350	if (!err)
2351		nilfs->ns_flushed_device = 0;
2352
2353	nilfs_transaction_unlock(sb);
2354	return err;
2355}
2356
2357#define FLUSH_FILE_BIT	(0x1) /* data file only */
2358#define FLUSH_DAT_BIT	BIT(NILFS_DAT_INO) /* DAT only */
2359
2360/**
2361 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2362 * @sci: segment constructor object
2363 */
2364static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2365{
 
 
2366	spin_lock(&sci->sc_state_lock);
2367	sci->sc_seq_accepted = sci->sc_seq_request;
 
2368	spin_unlock(&sci->sc_state_lock);
2369	del_timer_sync(&sci->sc_timer);
 
 
 
 
 
 
 
 
2370}
2371
2372/**
2373 * nilfs_segctor_notify - notify the result of request to caller threads
2374 * @sci: segment constructor object
2375 * @mode: mode of log forming
2376 * @err: error code to be notified
2377 */
2378static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2379{
2380	/* Clear requests (even when the construction failed) */
2381	spin_lock(&sci->sc_state_lock);
2382
2383	if (mode == SC_LSEG_SR) {
2384		sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2385		sci->sc_seq_done = sci->sc_seq_accepted;
2386		nilfs_segctor_wakeup(sci, err);
2387		sci->sc_flush_request = 0;
2388	} else {
2389		if (mode == SC_FLUSH_FILE)
2390			sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2391		else if (mode == SC_FLUSH_DAT)
2392			sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2393
2394		/* re-enable timer if checkpoint creation was not done */
2395		if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2396		    time_before(jiffies, sci->sc_timer.expires))
2397			add_timer(&sci->sc_timer);
2398	}
2399	spin_unlock(&sci->sc_state_lock);
2400}
2401
2402/**
2403 * nilfs_segctor_construct - form logs and write them to disk
2404 * @sci: segment constructor object
2405 * @mode: mode of log forming
2406 */
2407static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2408{
2409	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2410	struct nilfs_super_block **sbp;
2411	int err = 0;
2412
2413	nilfs_segctor_accept(sci);
2414
2415	if (nilfs_discontinued(nilfs))
2416		mode = SC_LSEG_SR;
2417	if (!nilfs_segctor_confirm(sci))
2418		err = nilfs_segctor_do_construct(sci, mode);
2419
2420	if (likely(!err)) {
2421		if (mode != SC_FLUSH_DAT)
2422			atomic_set(&nilfs->ns_ndirtyblks, 0);
2423		if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2424		    nilfs_discontinued(nilfs)) {
2425			down_write(&nilfs->ns_sem);
2426			err = -EIO;
2427			sbp = nilfs_prepare_super(sci->sc_super,
2428						  nilfs_sb_will_flip(nilfs));
2429			if (likely(sbp)) {
2430				nilfs_set_log_cursor(sbp[0], nilfs);
2431				err = nilfs_commit_super(sci->sc_super,
2432							 NILFS_SB_COMMIT);
2433			}
2434			up_write(&nilfs->ns_sem);
2435		}
2436	}
2437
2438	nilfs_segctor_notify(sci, mode, err);
2439	return err;
2440}
2441
2442static void nilfs_construction_timeout(struct timer_list *t)
2443{
2444	struct nilfs_sc_info *sci = from_timer(sci, t, sc_timer);
2445
2446	wake_up_process(sci->sc_timer_task);
2447}
2448
2449static void
2450nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2451{
2452	struct nilfs_inode_info *ii, *n;
2453
2454	list_for_each_entry_safe(ii, n, head, i_dirty) {
2455		if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2456			continue;
2457		list_del_init(&ii->i_dirty);
2458		truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2459		nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping);
2460		iput(&ii->vfs_inode);
2461	}
2462}
2463
2464int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2465			 void **kbufs)
2466{
2467	struct the_nilfs *nilfs = sb->s_fs_info;
2468	struct nilfs_sc_info *sci = nilfs->ns_writer;
2469	struct nilfs_transaction_info ti;
2470	int err;
2471
2472	if (unlikely(!sci))
2473		return -EROFS;
2474
2475	nilfs_transaction_lock(sb, &ti, 1);
2476
2477	err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2478	if (unlikely(err))
2479		goto out_unlock;
2480
2481	err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2482	if (unlikely(err)) {
2483		nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2484		goto out_unlock;
2485	}
2486
2487	sci->sc_freesegs = kbufs[4];
2488	sci->sc_nfreesegs = argv[4].v_nmembs;
2489	list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2490
2491	for (;;) {
2492		err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2493		nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2494
2495		if (likely(!err))
2496			break;
2497
2498		nilfs_warn(sb, "error %d cleaning segments", err);
2499		set_current_state(TASK_INTERRUPTIBLE);
2500		schedule_timeout(sci->sc_interval);
2501	}
2502	if (nilfs_test_opt(nilfs, DISCARD)) {
2503		int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2504						 sci->sc_nfreesegs);
2505		if (ret) {
2506			nilfs_warn(sb,
2507				   "error %d on discard request, turning discards off for the device",
2508				   ret);
2509			nilfs_clear_opt(nilfs, DISCARD);
2510		}
2511	}
2512
2513 out_unlock:
2514	sci->sc_freesegs = NULL;
2515	sci->sc_nfreesegs = 0;
2516	nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2517	nilfs_transaction_unlock(sb);
2518	return err;
2519}
2520
2521static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2522{
2523	struct nilfs_transaction_info ti;
2524
2525	nilfs_transaction_lock(sci->sc_super, &ti, 0);
2526	nilfs_segctor_construct(sci, mode);
2527
2528	/*
2529	 * Unclosed segment should be retried.  We do this using sc_timer.
2530	 * Timeout of sc_timer will invoke complete construction which leads
2531	 * to close the current logical segment.
2532	 */
2533	if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2534		nilfs_segctor_start_timer(sci);
2535
2536	nilfs_transaction_unlock(sci->sc_super);
2537}
2538
2539static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2540{
2541	int mode = 0;
2542
2543	spin_lock(&sci->sc_state_lock);
2544	mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2545		SC_FLUSH_DAT : SC_FLUSH_FILE;
2546	spin_unlock(&sci->sc_state_lock);
2547
2548	if (mode) {
2549		nilfs_segctor_do_construct(sci, mode);
2550
2551		spin_lock(&sci->sc_state_lock);
2552		sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2553			~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2554		spin_unlock(&sci->sc_state_lock);
2555	}
2556	clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2557}
2558
2559static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2560{
2561	if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2562	    time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2563		if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2564			return SC_FLUSH_FILE;
2565		else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2566			return SC_FLUSH_DAT;
2567	}
2568	return SC_LSEG_SR;
2569}
2570
2571/**
2572 * nilfs_segctor_thread - main loop of the segment constructor thread.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2573 * @arg: pointer to a struct nilfs_sc_info.
2574 *
2575 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2576 * to execute segment constructions.
 
 
 
 
2577 */
2578static int nilfs_segctor_thread(void *arg)
2579{
2580	struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2581	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2582	int timeout = 0;
2583
2584	sci->sc_timer_task = current;
2585
2586	/* start sync. */
2587	sci->sc_task = current;
2588	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2589	nilfs_info(sci->sc_super,
2590		   "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
2591		   sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2592
2593	set_freezable();
2594	spin_lock(&sci->sc_state_lock);
2595 loop:
2596	for (;;) {
2597		int mode;
2598
2599		if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2600			goto end_thread;
2601
2602		if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2603			mode = SC_LSEG_SR;
2604		else if (sci->sc_flush_request)
2605			mode = nilfs_segctor_flush_mode(sci);
2606		else
2607			break;
2608
2609		spin_unlock(&sci->sc_state_lock);
2610		nilfs_segctor_thread_construct(sci, mode);
2611		spin_lock(&sci->sc_state_lock);
2612		timeout = 0;
2613	}
2614
2615
2616	if (freezing(current)) {
2617		spin_unlock(&sci->sc_state_lock);
2618		try_to_freeze();
2619		spin_lock(&sci->sc_state_lock);
2620	} else {
2621		DEFINE_WAIT(wait);
2622		int should_sleep = 1;
 
 
 
 
 
 
2623
2624		prepare_to_wait(&sci->sc_wait_daemon, &wait,
2625				TASK_INTERRUPTIBLE);
2626
2627		if (sci->sc_seq_request != sci->sc_seq_done)
2628			should_sleep = 0;
2629		else if (sci->sc_flush_request)
2630			should_sleep = 0;
2631		else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2632			should_sleep = time_before(jiffies,
2633					sci->sc_timer.expires);
2634
2635		if (should_sleep) {
2636			spin_unlock(&sci->sc_state_lock);
2637			schedule();
2638			spin_lock(&sci->sc_state_lock);
2639		}
2640		finish_wait(&sci->sc_wait_daemon, &wait);
2641		timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2642			   time_after_eq(jiffies, sci->sc_timer.expires));
2643
2644		if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2645			set_nilfs_discontinued(nilfs);
 
 
 
2646	}
2647	goto loop;
2648
2649 end_thread:
2650	/* end sync. */
 
2651	sci->sc_task = NULL;
2652	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
2653	spin_unlock(&sci->sc_state_lock);
2654	return 0;
2655}
2656
2657static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2658{
2659	struct task_struct *t;
2660
2661	t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2662	if (IS_ERR(t)) {
2663		int err = PTR_ERR(t);
2664
2665		nilfs_err(sci->sc_super, "error %d creating segctord thread",
2666			  err);
2667		return err;
2668	}
2669	wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2670	return 0;
2671}
2672
2673static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2674	__acquires(&sci->sc_state_lock)
2675	__releases(&sci->sc_state_lock)
2676{
2677	sci->sc_state |= NILFS_SEGCTOR_QUIT;
2678
2679	while (sci->sc_task) {
2680		wake_up(&sci->sc_wait_daemon);
2681		spin_unlock(&sci->sc_state_lock);
2682		wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2683		spin_lock(&sci->sc_state_lock);
2684	}
2685}
2686
2687/*
2688 * Setup & clean-up functions
2689 */
2690static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2691					       struct nilfs_root *root)
2692{
2693	struct the_nilfs *nilfs = sb->s_fs_info;
2694	struct nilfs_sc_info *sci;
2695
2696	sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2697	if (!sci)
2698		return NULL;
2699
2700	sci->sc_super = sb;
2701
2702	nilfs_get_root(root);
2703	sci->sc_root = root;
2704
2705	init_waitqueue_head(&sci->sc_wait_request);
2706	init_waitqueue_head(&sci->sc_wait_daemon);
2707	init_waitqueue_head(&sci->sc_wait_task);
2708	spin_lock_init(&sci->sc_state_lock);
2709	INIT_LIST_HEAD(&sci->sc_dirty_files);
2710	INIT_LIST_HEAD(&sci->sc_segbufs);
2711	INIT_LIST_HEAD(&sci->sc_write_logs);
2712	INIT_LIST_HEAD(&sci->sc_gc_inodes);
2713	INIT_LIST_HEAD(&sci->sc_iput_queue);
2714	INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
2715	timer_setup(&sci->sc_timer, nilfs_construction_timeout, 0);
2716
2717	sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2718	sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2719	sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2720
2721	if (nilfs->ns_interval)
2722		sci->sc_interval = HZ * nilfs->ns_interval;
2723	if (nilfs->ns_watermark)
2724		sci->sc_watermark = nilfs->ns_watermark;
2725	return sci;
2726}
2727
2728static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2729{
2730	int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2731
2732	/*
2733	 * The segctord thread was stopped and its timer was removed.
2734	 * But some tasks remain.
2735	 */
2736	do {
2737		struct nilfs_transaction_info ti;
2738
2739		nilfs_transaction_lock(sci->sc_super, &ti, 0);
2740		ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2741		nilfs_transaction_unlock(sci->sc_super);
2742
2743		flush_work(&sci->sc_iput_work);
2744
2745	} while (ret && ret != -EROFS && retrycount-- > 0);
2746}
2747
2748/**
2749 * nilfs_segctor_destroy - destroy the segment constructor.
2750 * @sci: nilfs_sc_info
2751 *
2752 * nilfs_segctor_destroy() kills the segctord thread and frees
2753 * the nilfs_sc_info struct.
2754 * Caller must hold the segment semaphore.
2755 */
2756static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2757{
2758	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2759	int flag;
2760
2761	up_write(&nilfs->ns_segctor_sem);
2762
 
 
 
 
 
2763	spin_lock(&sci->sc_state_lock);
2764	nilfs_segctor_kill_thread(sci);
2765	flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2766		|| sci->sc_seq_request != sci->sc_seq_done);
2767	spin_unlock(&sci->sc_state_lock);
2768
 
 
 
 
 
 
 
2769	if (flush_work(&sci->sc_iput_work))
2770		flag = true;
2771
2772	if (flag || !nilfs_segctor_confirm(sci))
2773		nilfs_segctor_write_out(sci);
2774
2775	if (!list_empty(&sci->sc_dirty_files)) {
2776		nilfs_warn(sci->sc_super,
2777			   "disposed unprocessed dirty file(s) when stopping log writer");
2778		nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2779	}
2780
2781	if (!list_empty(&sci->sc_iput_queue)) {
2782		nilfs_warn(sci->sc_super,
2783			   "disposed unprocessed inode(s) in iput queue when stopping log writer");
2784		nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2785	}
2786
2787	WARN_ON(!list_empty(&sci->sc_segbufs));
2788	WARN_ON(!list_empty(&sci->sc_write_logs));
2789
2790	nilfs_put_root(sci->sc_root);
2791
2792	down_write(&nilfs->ns_segctor_sem);
2793
2794	timer_shutdown_sync(&sci->sc_timer);
2795	kfree(sci);
2796}
2797
2798/**
2799 * nilfs_attach_log_writer - attach log writer
2800 * @sb: super block instance
2801 * @root: root object of the current filesystem tree
2802 *
2803 * This allocates a log writer object, initializes it, and starts the
2804 * log writer.
2805 *
2806 * Return Value: On success, 0 is returned. On error, one of the following
2807 * negative error code is returned.
2808 *
2809 * %-ENOMEM - Insufficient memory available.
2810 */
2811int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2812{
2813	struct the_nilfs *nilfs = sb->s_fs_info;
 
 
2814	int err;
2815
2816	if (nilfs->ns_writer) {
2817		/*
2818		 * This happens if the filesystem is made read-only by
2819		 * __nilfs_error or nilfs_remount and then remounted
2820		 * read/write.  In these cases, reuse the existing
2821		 * writer.
2822		 */
2823		return 0;
2824	}
2825
2826	nilfs->ns_writer = nilfs_segctor_new(sb, root);
2827	if (!nilfs->ns_writer)
2828		return -ENOMEM;
2829
2830	inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL);
2831
2832	err = nilfs_segctor_start_thread(nilfs->ns_writer);
2833	if (unlikely(err))
 
2834		nilfs_detach_log_writer(sb);
 
 
 
 
2835
2836	return err;
 
2837}
2838
2839/**
2840 * nilfs_detach_log_writer - destroy log writer
2841 * @sb: super block instance
2842 *
2843 * This kills log writer daemon, frees the log writer object, and
2844 * destroys list of dirty files.
2845 */
2846void nilfs_detach_log_writer(struct super_block *sb)
2847{
2848	struct the_nilfs *nilfs = sb->s_fs_info;
2849	LIST_HEAD(garbage_list);
2850
2851	down_write(&nilfs->ns_segctor_sem);
2852	if (nilfs->ns_writer) {
2853		nilfs_segctor_destroy(nilfs->ns_writer);
2854		nilfs->ns_writer = NULL;
2855	}
2856	set_nilfs_purging(nilfs);
2857
2858	/* Force to free the list of dirty files */
2859	spin_lock(&nilfs->ns_inode_lock);
2860	if (!list_empty(&nilfs->ns_dirty_files)) {
2861		list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2862		nilfs_warn(sb,
2863			   "disposed unprocessed dirty file(s) when detaching log writer");
2864	}
2865	spin_unlock(&nilfs->ns_inode_lock);
2866	up_write(&nilfs->ns_segctor_sem);
2867
2868	nilfs_dispose_list(nilfs, &garbage_list, 1);
2869	clear_nilfs_purging(nilfs);
2870}
v6.13.7
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * NILFS segment constructor.
   4 *
   5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   6 *
   7 * Written by Ryusuke Konishi.
   8 *
   9 */
  10
  11#include <linux/pagemap.h>
  12#include <linux/buffer_head.h>
  13#include <linux/writeback.h>
  14#include <linux/bitops.h>
  15#include <linux/bio.h>
  16#include <linux/completion.h>
  17#include <linux/blkdev.h>
  18#include <linux/backing-dev.h>
  19#include <linux/freezer.h>
  20#include <linux/kthread.h>
  21#include <linux/crc32.h>
  22#include <linux/pagevec.h>
  23#include <linux/slab.h>
  24#include <linux/sched/signal.h>
  25
  26#include "nilfs.h"
  27#include "btnode.h"
  28#include "page.h"
  29#include "segment.h"
  30#include "sufile.h"
  31#include "cpfile.h"
  32#include "ifile.h"
  33#include "segbuf.h"
  34
  35
  36/*
  37 * Segment constructor
  38 */
  39#define SC_N_INODEVEC	16   /* Size of locally allocated inode vector */
  40
  41#define SC_MAX_SEGDELTA 64   /*
  42			      * Upper limit of the number of segments
  43			      * appended in collection retry loop
  44			      */
  45
  46/* Construction mode */
  47enum {
  48	SC_LSEG_SR = 1,	/* Make a logical segment having a super root */
  49	SC_LSEG_DSYNC,	/*
  50			 * Flush data blocks of a given file and make
  51			 * a logical segment without a super root.
  52			 */
  53	SC_FLUSH_FILE,	/*
  54			 * Flush data files, leads to segment writes without
  55			 * creating a checkpoint.
  56			 */
  57	SC_FLUSH_DAT,	/*
  58			 * Flush DAT file.  This also creates segments
  59			 * without a checkpoint.
  60			 */
  61};
  62
  63/* Stage numbers of dirty block collection */
  64enum {
  65	NILFS_ST_INIT = 0,
  66	NILFS_ST_GC,		/* Collecting dirty blocks for GC */
  67	NILFS_ST_FILE,
  68	NILFS_ST_IFILE,
  69	NILFS_ST_CPFILE,
  70	NILFS_ST_SUFILE,
  71	NILFS_ST_DAT,
  72	NILFS_ST_SR,		/* Super root */
  73	NILFS_ST_DSYNC,		/* Data sync blocks */
  74	NILFS_ST_DONE,
  75};
  76
  77#define CREATE_TRACE_POINTS
  78#include <trace/events/nilfs2.h>
  79
  80/*
  81 * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() are
  82 * wrapper functions of stage count (nilfs_sc_info->sc_stage.scnt). Users of
  83 * the variable must use them because transition of stage count must involve
  84 * trace events (trace_nilfs2_collection_stage_transition).
  85 *
  86 * nilfs_sc_cstage_get() isn't required for the above purpose because it doesn't
  87 * produce tracepoint events. It is provided just for making the intention
  88 * clear.
  89 */
  90static inline void nilfs_sc_cstage_inc(struct nilfs_sc_info *sci)
  91{
  92	sci->sc_stage.scnt++;
  93	trace_nilfs2_collection_stage_transition(sci);
  94}
  95
  96static inline void nilfs_sc_cstage_set(struct nilfs_sc_info *sci, int next_scnt)
  97{
  98	sci->sc_stage.scnt = next_scnt;
  99	trace_nilfs2_collection_stage_transition(sci);
 100}
 101
 102static inline int nilfs_sc_cstage_get(struct nilfs_sc_info *sci)
 103{
 104	return sci->sc_stage.scnt;
 105}
 106
 107/* State flags of collection */
 108#define NILFS_CF_NODE		0x0001	/* Collecting node blocks */
 109#define NILFS_CF_IFILE_STARTED	0x0002	/* IFILE stage has started */
 110#define NILFS_CF_SUFREED	0x0004	/* segment usages has been freed */
 111#define NILFS_CF_HISTORY_MASK	(NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
 112
 113/* Operations depending on the construction mode and file type */
 114struct nilfs_sc_operations {
 115	int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
 116			    struct inode *);
 117	int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
 118			    struct inode *);
 119	int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
 120			    struct inode *);
 121	void (*write_data_binfo)(struct nilfs_sc_info *,
 122				 struct nilfs_segsum_pointer *,
 123				 union nilfs_binfo *);
 124	void (*write_node_binfo)(struct nilfs_sc_info *,
 125				 struct nilfs_segsum_pointer *,
 126				 union nilfs_binfo *);
 127};
 128
 129/*
 130 * Other definitions
 131 */
 132static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
 133static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
 134static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
 135static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
 136
 137#define nilfs_cnt32_ge(a, b)   \
 138	(typecheck(__u32, a) && typecheck(__u32, b) && \
 139	 ((__s32)((a) - (b)) >= 0))
 140
 141static int nilfs_prepare_segment_lock(struct super_block *sb,
 142				      struct nilfs_transaction_info *ti)
 143{
 144	struct nilfs_transaction_info *cur_ti = current->journal_info;
 145	void *save = NULL;
 146
 147	if (cur_ti) {
 148		if (cur_ti->ti_magic == NILFS_TI_MAGIC)
 149			return ++cur_ti->ti_count;
 150
 151		/*
 152		 * If journal_info field is occupied by other FS,
 153		 * it is saved and will be restored on
 154		 * nilfs_transaction_commit().
 155		 */
 156		nilfs_warn(sb, "journal info from a different FS");
 157		save = current->journal_info;
 158	}
 159	if (!ti) {
 160		ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
 161		if (!ti)
 162			return -ENOMEM;
 163		ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
 164	} else {
 165		ti->ti_flags = 0;
 166	}
 167	ti->ti_count = 0;
 168	ti->ti_save = save;
 169	ti->ti_magic = NILFS_TI_MAGIC;
 170	current->journal_info = ti;
 171	return 0;
 172}
 173
 174/**
 175 * nilfs_transaction_begin - start indivisible file operations.
 176 * @sb: super block
 177 * @ti: nilfs_transaction_info
 178 * @vacancy_check: flags for vacancy rate checks
 179 *
 180 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
 181 * the segment semaphore, to make a segment construction and write tasks
 182 * exclusive.  The function is used with nilfs_transaction_commit() in pairs.
 183 * The region enclosed by these two functions can be nested.  To avoid a
 184 * deadlock, the semaphore is only acquired or released in the outermost call.
 185 *
 186 * This function allocates a nilfs_transaction_info struct to keep context
 187 * information on it.  It is initialized and hooked onto the current task in
 188 * the outermost call.  If a pre-allocated struct is given to @ti, it is used
 189 * instead; otherwise a new struct is assigned from a slab.
 190 *
 191 * When @vacancy_check flag is set, this function will check the amount of
 192 * free space, and will wait for the GC to reclaim disk space if low capacity.
 193 *
 194 * Return Value: On success, 0 is returned. On error, one of the following
 195 * negative error code is returned.
 196 *
 197 * %-ENOMEM - Insufficient memory available.
 198 *
 199 * %-ENOSPC - No space left on device
 200 */
 201int nilfs_transaction_begin(struct super_block *sb,
 202			    struct nilfs_transaction_info *ti,
 203			    int vacancy_check)
 204{
 205	struct the_nilfs *nilfs;
 206	int ret = nilfs_prepare_segment_lock(sb, ti);
 207	struct nilfs_transaction_info *trace_ti;
 208
 209	if (unlikely(ret < 0))
 210		return ret;
 211	if (ret > 0) {
 212		trace_ti = current->journal_info;
 213
 214		trace_nilfs2_transaction_transition(sb, trace_ti,
 215				    trace_ti->ti_count, trace_ti->ti_flags,
 216				    TRACE_NILFS2_TRANSACTION_BEGIN);
 217		return 0;
 218	}
 219
 220	sb_start_intwrite(sb);
 221
 222	nilfs = sb->s_fs_info;
 223	down_read(&nilfs->ns_segctor_sem);
 224	if (vacancy_check && nilfs_near_disk_full(nilfs)) {
 225		up_read(&nilfs->ns_segctor_sem);
 226		ret = -ENOSPC;
 227		goto failed;
 228	}
 229
 230	trace_ti = current->journal_info;
 231	trace_nilfs2_transaction_transition(sb, trace_ti, trace_ti->ti_count,
 232					    trace_ti->ti_flags,
 233					    TRACE_NILFS2_TRANSACTION_BEGIN);
 234	return 0;
 235
 236 failed:
 237	ti = current->journal_info;
 238	current->journal_info = ti->ti_save;
 239	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 240		kmem_cache_free(nilfs_transaction_cachep, ti);
 241	sb_end_intwrite(sb);
 242	return ret;
 243}
 244
 245/**
 246 * nilfs_transaction_commit - commit indivisible file operations.
 247 * @sb: super block
 248 *
 249 * nilfs_transaction_commit() releases the read semaphore which is
 250 * acquired by nilfs_transaction_begin(). This is only performed
 251 * in outermost call of this function.  If a commit flag is set,
 252 * nilfs_transaction_commit() sets a timer to start the segment
 253 * constructor.  If a sync flag is set, it starts construction
 254 * directly.
 255 */
 256int nilfs_transaction_commit(struct super_block *sb)
 257{
 258	struct nilfs_transaction_info *ti = current->journal_info;
 259	struct the_nilfs *nilfs = sb->s_fs_info;
 260	int err = 0;
 261
 262	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 263	ti->ti_flags |= NILFS_TI_COMMIT;
 264	if (ti->ti_count > 0) {
 265		ti->ti_count--;
 266		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 267			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
 268		return 0;
 269	}
 270	if (nilfs->ns_writer) {
 271		struct nilfs_sc_info *sci = nilfs->ns_writer;
 272
 273		if (ti->ti_flags & NILFS_TI_COMMIT)
 274			nilfs_segctor_start_timer(sci);
 275		if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
 276			nilfs_segctor_do_flush(sci, 0);
 277	}
 278	up_read(&nilfs->ns_segctor_sem);
 279	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 280			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_COMMIT);
 281
 282	current->journal_info = ti->ti_save;
 283
 284	if (ti->ti_flags & NILFS_TI_SYNC)
 285		err = nilfs_construct_segment(sb);
 286	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 287		kmem_cache_free(nilfs_transaction_cachep, ti);
 288	sb_end_intwrite(sb);
 289	return err;
 290}
 291
 292void nilfs_transaction_abort(struct super_block *sb)
 293{
 294	struct nilfs_transaction_info *ti = current->journal_info;
 295	struct the_nilfs *nilfs = sb->s_fs_info;
 296
 297	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 298	if (ti->ti_count > 0) {
 299		ti->ti_count--;
 300		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 301			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
 302		return;
 303	}
 304	up_read(&nilfs->ns_segctor_sem);
 305
 306	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 307		    ti->ti_flags, TRACE_NILFS2_TRANSACTION_ABORT);
 308
 309	current->journal_info = ti->ti_save;
 310	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 311		kmem_cache_free(nilfs_transaction_cachep, ti);
 312	sb_end_intwrite(sb);
 313}
 314
 315void nilfs_relax_pressure_in_lock(struct super_block *sb)
 316{
 317	struct the_nilfs *nilfs = sb->s_fs_info;
 318	struct nilfs_sc_info *sci = nilfs->ns_writer;
 319
 320	if (sb_rdonly(sb) || unlikely(!sci) || !sci->sc_flush_request)
 321		return;
 322
 323	set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
 324	up_read(&nilfs->ns_segctor_sem);
 325
 326	down_write(&nilfs->ns_segctor_sem);
 327	if (sci->sc_flush_request &&
 328	    test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
 329		struct nilfs_transaction_info *ti = current->journal_info;
 330
 331		ti->ti_flags |= NILFS_TI_WRITER;
 332		nilfs_segctor_do_immediate_flush(sci);
 333		ti->ti_flags &= ~NILFS_TI_WRITER;
 334	}
 335	downgrade_write(&nilfs->ns_segctor_sem);
 336}
 337
 338static void nilfs_transaction_lock(struct super_block *sb,
 339				   struct nilfs_transaction_info *ti,
 340				   int gcflag)
 341{
 342	struct nilfs_transaction_info *cur_ti = current->journal_info;
 343	struct the_nilfs *nilfs = sb->s_fs_info;
 344	struct nilfs_sc_info *sci = nilfs->ns_writer;
 345
 346	WARN_ON(cur_ti);
 347	ti->ti_flags = NILFS_TI_WRITER;
 348	ti->ti_count = 0;
 349	ti->ti_save = cur_ti;
 350	ti->ti_magic = NILFS_TI_MAGIC;
 351	current->journal_info = ti;
 352
 353	for (;;) {
 354		trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 355			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_TRYLOCK);
 356
 357		down_write(&nilfs->ns_segctor_sem);
 358		if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
 359			break;
 360
 361		nilfs_segctor_do_immediate_flush(sci);
 362
 363		up_write(&nilfs->ns_segctor_sem);
 364		cond_resched();
 365	}
 366	if (gcflag)
 367		ti->ti_flags |= NILFS_TI_GC;
 368
 369	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 370			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_LOCK);
 371}
 372
 373static void nilfs_transaction_unlock(struct super_block *sb)
 374{
 375	struct nilfs_transaction_info *ti = current->journal_info;
 376	struct the_nilfs *nilfs = sb->s_fs_info;
 377
 378	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 379	BUG_ON(ti->ti_count > 0);
 380
 381	up_write(&nilfs->ns_segctor_sem);
 382	current->journal_info = ti->ti_save;
 383
 384	trace_nilfs2_transaction_transition(sb, ti, ti->ti_count,
 385			    ti->ti_flags, TRACE_NILFS2_TRANSACTION_UNLOCK);
 386}
 387
 388static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
 389					    struct nilfs_segsum_pointer *ssp,
 390					    unsigned int bytes)
 391{
 392	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 393	unsigned int blocksize = sci->sc_super->s_blocksize;
 394	void *p;
 395
 396	if (unlikely(ssp->offset + bytes > blocksize)) {
 397		ssp->offset = 0;
 398		BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
 399					       &segbuf->sb_segsum_buffers));
 400		ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
 401	}
 402	p = ssp->bh->b_data + ssp->offset;
 403	ssp->offset += bytes;
 404	return p;
 405}
 406
 407/**
 408 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
 409 * @sci: nilfs_sc_info
 410 */
 411static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
 412{
 413	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 414	struct buffer_head *sumbh;
 415	unsigned int sumbytes;
 416	unsigned int flags = 0;
 417	int err;
 418
 419	if (nilfs_doing_gc())
 420		flags = NILFS_SS_GC;
 421	err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
 422	if (unlikely(err))
 423		return err;
 424
 425	sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
 426	sumbytes = segbuf->sb_sum.sumbytes;
 427	sci->sc_finfo_ptr.bh = sumbh;  sci->sc_finfo_ptr.offset = sumbytes;
 428	sci->sc_binfo_ptr.bh = sumbh;  sci->sc_binfo_ptr.offset = sumbytes;
 429	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 430	return 0;
 431}
 432
 433/**
 434 * nilfs_segctor_zeropad_segsum - zero pad the rest of the segment summary area
 435 * @sci: segment constructor object
 436 *
 437 * nilfs_segctor_zeropad_segsum() zero-fills unallocated space at the end of
 438 * the current segment summary block.
 439 */
 440static void nilfs_segctor_zeropad_segsum(struct nilfs_sc_info *sci)
 441{
 442	struct nilfs_segsum_pointer *ssp;
 443
 444	ssp = sci->sc_blk_cnt > 0 ? &sci->sc_binfo_ptr : &sci->sc_finfo_ptr;
 445	if (ssp->offset < ssp->bh->b_size)
 446		memset(ssp->bh->b_data + ssp->offset, 0,
 447		       ssp->bh->b_size - ssp->offset);
 448}
 449
 450static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 451{
 452	sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
 453	if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
 454		return -E2BIG; /*
 455				* The current segment is filled up
 456				* (internal code)
 457				*/
 458	nilfs_segctor_zeropad_segsum(sci);
 459	sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
 460	return nilfs_segctor_reset_segment_buffer(sci);
 461}
 462
 463static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
 464{
 465	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 466	int err;
 467
 468	if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
 469		err = nilfs_segctor_feed_segment(sci);
 470		if (err)
 471			return err;
 472		segbuf = sci->sc_curseg;
 473	}
 474	err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
 475	if (likely(!err))
 476		segbuf->sb_sum.flags |= NILFS_SS_SR;
 477	return err;
 478}
 479
 480/*
 481 * Functions for making segment summary and payloads
 482 */
 483static int nilfs_segctor_segsum_block_required(
 484	struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
 485	unsigned int binfo_size)
 486{
 487	unsigned int blocksize = sci->sc_super->s_blocksize;
 488	/* Size of finfo and binfo is enough small against blocksize */
 489
 490	return ssp->offset + binfo_size +
 491		(!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
 492		blocksize;
 493}
 494
 495static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
 496				      struct inode *inode)
 497{
 498	sci->sc_curseg->sb_sum.nfinfo++;
 499	sci->sc_binfo_ptr = sci->sc_finfo_ptr;
 500	nilfs_segctor_map_segsum_entry(
 501		sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
 502
 503	if (NILFS_I(inode)->i_root &&
 504	    !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
 505		set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
 506	/* skip finfo */
 507}
 508
 509static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
 510				    struct inode *inode)
 511{
 512	struct nilfs_finfo *finfo;
 513	struct nilfs_inode_info *ii;
 514	struct nilfs_segment_buffer *segbuf;
 515	__u64 cno;
 516
 517	if (sci->sc_blk_cnt == 0)
 518		return;
 519
 520	ii = NILFS_I(inode);
 521
 522	if (ii->i_type & NILFS_I_TYPE_GC)
 523		cno = ii->i_cno;
 524	else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
 525		cno = 0;
 526	else
 527		cno = sci->sc_cno;
 528
 529	finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
 530						 sizeof(*finfo));
 531	finfo->fi_ino = cpu_to_le64(inode->i_ino);
 532	finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
 533	finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
 534	finfo->fi_cno = cpu_to_le64(cno);
 535
 536	segbuf = sci->sc_curseg;
 537	segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
 538		sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
 539	sci->sc_finfo_ptr = sci->sc_binfo_ptr;
 540	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 541}
 542
 543static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
 544					struct buffer_head *bh,
 545					struct inode *inode,
 546					unsigned int binfo_size)
 547{
 548	struct nilfs_segment_buffer *segbuf;
 549	int required, err = 0;
 550
 551 retry:
 552	segbuf = sci->sc_curseg;
 553	required = nilfs_segctor_segsum_block_required(
 554		sci, &sci->sc_binfo_ptr, binfo_size);
 555	if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
 556		nilfs_segctor_end_finfo(sci, inode);
 557		err = nilfs_segctor_feed_segment(sci);
 558		if (err)
 559			return err;
 560		goto retry;
 561	}
 562	if (unlikely(required)) {
 563		nilfs_segctor_zeropad_segsum(sci);
 564		err = nilfs_segbuf_extend_segsum(segbuf);
 565		if (unlikely(err))
 566			goto failed;
 567	}
 568	if (sci->sc_blk_cnt == 0)
 569		nilfs_segctor_begin_finfo(sci, inode);
 570
 571	nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
 572	/* Substitution to vblocknr is delayed until update_blocknr() */
 573	nilfs_segbuf_add_file_buffer(segbuf, bh);
 574	sci->sc_blk_cnt++;
 575 failed:
 576	return err;
 577}
 578
 579/*
 580 * Callback functions that enumerate, mark, and collect dirty blocks
 581 */
 582static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
 583				   struct buffer_head *bh, struct inode *inode)
 584{
 585	int err;
 586
 587	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 588	if (err < 0)
 589		return err;
 590
 591	err = nilfs_segctor_add_file_block(sci, bh, inode,
 592					   sizeof(struct nilfs_binfo_v));
 593	if (!err)
 594		sci->sc_datablk_cnt++;
 595	return err;
 596}
 597
 598static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
 599				   struct buffer_head *bh,
 600				   struct inode *inode)
 601{
 602	return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 603}
 604
 605static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
 606				   struct buffer_head *bh,
 607				   struct inode *inode)
 608{
 609	WARN_ON(!buffer_dirty(bh));
 610	return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 611}
 612
 613static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
 614					struct nilfs_segsum_pointer *ssp,
 615					union nilfs_binfo *binfo)
 616{
 617	struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
 618		sci, ssp, sizeof(*binfo_v));
 619	*binfo_v = binfo->bi_v;
 620}
 621
 622static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
 623					struct nilfs_segsum_pointer *ssp,
 624					union nilfs_binfo *binfo)
 625{
 626	__le64 *vblocknr = nilfs_segctor_map_segsum_entry(
 627		sci, ssp, sizeof(*vblocknr));
 628	*vblocknr = binfo->bi_v.bi_vblocknr;
 629}
 630
 631static const struct nilfs_sc_operations nilfs_sc_file_ops = {
 632	.collect_data = nilfs_collect_file_data,
 633	.collect_node = nilfs_collect_file_node,
 634	.collect_bmap = nilfs_collect_file_bmap,
 635	.write_data_binfo = nilfs_write_file_data_binfo,
 636	.write_node_binfo = nilfs_write_file_node_binfo,
 637};
 638
 639static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
 640				  struct buffer_head *bh, struct inode *inode)
 641{
 642	int err;
 643
 644	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 645	if (err < 0)
 646		return err;
 647
 648	err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 649	if (!err)
 650		sci->sc_datablk_cnt++;
 651	return err;
 652}
 653
 654static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
 655				  struct buffer_head *bh, struct inode *inode)
 656{
 657	WARN_ON(!buffer_dirty(bh));
 658	return nilfs_segctor_add_file_block(sci, bh, inode,
 659					    sizeof(struct nilfs_binfo_dat));
 660}
 661
 662static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
 663				       struct nilfs_segsum_pointer *ssp,
 664				       union nilfs_binfo *binfo)
 665{
 666	__le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
 667							  sizeof(*blkoff));
 668	*blkoff = binfo->bi_dat.bi_blkoff;
 669}
 670
 671static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
 672				       struct nilfs_segsum_pointer *ssp,
 673				       union nilfs_binfo *binfo)
 674{
 675	struct nilfs_binfo_dat *binfo_dat =
 676		nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
 677	*binfo_dat = binfo->bi_dat;
 678}
 679
 680static const struct nilfs_sc_operations nilfs_sc_dat_ops = {
 681	.collect_data = nilfs_collect_dat_data,
 682	.collect_node = nilfs_collect_file_node,
 683	.collect_bmap = nilfs_collect_dat_bmap,
 684	.write_data_binfo = nilfs_write_dat_data_binfo,
 685	.write_node_binfo = nilfs_write_dat_node_binfo,
 686};
 687
 688static const struct nilfs_sc_operations nilfs_sc_dsync_ops = {
 689	.collect_data = nilfs_collect_file_data,
 690	.collect_node = NULL,
 691	.collect_bmap = NULL,
 692	.write_data_binfo = nilfs_write_file_data_binfo,
 693	.write_node_binfo = NULL,
 694};
 695
 696static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
 697					      struct list_head *listp,
 698					      size_t nlimit,
 699					      loff_t start, loff_t end)
 700{
 701	struct address_space *mapping = inode->i_mapping;
 702	struct folio_batch fbatch;
 703	pgoff_t index = 0, last = ULONG_MAX;
 704	size_t ndirties = 0;
 705	int i;
 706
 707	if (unlikely(start != 0 || end != LLONG_MAX)) {
 708		/*
 709		 * A valid range is given for sync-ing data pages. The
 710		 * range is rounded to per-page; extra dirty buffers
 711		 * may be included if blocksize < pagesize.
 712		 */
 713		index = start >> PAGE_SHIFT;
 714		last = end >> PAGE_SHIFT;
 715	}
 716	folio_batch_init(&fbatch);
 717 repeat:
 718	if (unlikely(index > last) ||
 719	      !filemap_get_folios_tag(mapping, &index, last,
 720		      PAGECACHE_TAG_DIRTY, &fbatch))
 721		return ndirties;
 722
 723	for (i = 0; i < folio_batch_count(&fbatch); i++) {
 724		struct buffer_head *bh, *head;
 725		struct folio *folio = fbatch.folios[i];
 726
 727		folio_lock(folio);
 728		if (unlikely(folio->mapping != mapping)) {
 729			/* Exclude folios removed from the address space */
 730			folio_unlock(folio);
 731			continue;
 732		}
 733		head = folio_buffers(folio);
 734		if (!head)
 735			head = create_empty_buffers(folio,
 736					i_blocksize(inode), 0);
 
 737
 738		bh = head;
 739		do {
 740			if (!buffer_dirty(bh) || buffer_async_write(bh))
 741				continue;
 742			get_bh(bh);
 743			list_add_tail(&bh->b_assoc_buffers, listp);
 744			ndirties++;
 745			if (unlikely(ndirties >= nlimit)) {
 746				folio_unlock(folio);
 747				folio_batch_release(&fbatch);
 748				cond_resched();
 749				return ndirties;
 750			}
 751		} while (bh = bh->b_this_page, bh != head);
 752
 753		folio_unlock(folio);
 754	}
 755	folio_batch_release(&fbatch);
 756	cond_resched();
 757	goto repeat;
 758}
 759
 760static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
 761					    struct list_head *listp)
 762{
 763	struct nilfs_inode_info *ii = NILFS_I(inode);
 764	struct inode *btnc_inode = ii->i_assoc_inode;
 765	struct folio_batch fbatch;
 766	struct buffer_head *bh, *head;
 767	unsigned int i;
 768	pgoff_t index = 0;
 769
 770	if (!btnc_inode)
 771		return;
 772	folio_batch_init(&fbatch);
 773
 774	while (filemap_get_folios_tag(btnc_inode->i_mapping, &index,
 775				(pgoff_t)-1, PAGECACHE_TAG_DIRTY, &fbatch)) {
 776		for (i = 0; i < folio_batch_count(&fbatch); i++) {
 777			bh = head = folio_buffers(fbatch.folios[i]);
 778			do {
 779				if (buffer_dirty(bh) &&
 780						!buffer_async_write(bh)) {
 781					get_bh(bh);
 782					list_add_tail(&bh->b_assoc_buffers,
 783						      listp);
 784				}
 785				bh = bh->b_this_page;
 786			} while (bh != head);
 787		}
 788		folio_batch_release(&fbatch);
 789		cond_resched();
 790	}
 791}
 792
 793static void nilfs_dispose_list(struct the_nilfs *nilfs,
 794			       struct list_head *head, int force)
 795{
 796	struct nilfs_inode_info *ii, *n;
 797	struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
 798	unsigned int nv = 0;
 799
 800	while (!list_empty(head)) {
 801		spin_lock(&nilfs->ns_inode_lock);
 802		list_for_each_entry_safe(ii, n, head, i_dirty) {
 803			list_del_init(&ii->i_dirty);
 804			if (force) {
 805				if (unlikely(ii->i_bh)) {
 806					brelse(ii->i_bh);
 807					ii->i_bh = NULL;
 808				}
 809			} else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
 810				set_bit(NILFS_I_QUEUED, &ii->i_state);
 811				list_add_tail(&ii->i_dirty,
 812					      &nilfs->ns_dirty_files);
 813				continue;
 814			}
 815			ivec[nv++] = ii;
 816			if (nv == SC_N_INODEVEC)
 817				break;
 818		}
 819		spin_unlock(&nilfs->ns_inode_lock);
 820
 821		for (pii = ivec; nv > 0; pii++, nv--)
 822			iput(&(*pii)->vfs_inode);
 823	}
 824}
 825
 826static void nilfs_iput_work_func(struct work_struct *work)
 827{
 828	struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info,
 829						 sc_iput_work);
 830	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 831
 832	nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0);
 833}
 834
 835static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
 836				     struct nilfs_root *root)
 837{
 838	int ret = 0;
 839
 840	if (nilfs_mdt_fetch_dirty(root->ifile))
 841		ret++;
 842	if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
 843		ret++;
 844	if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
 845		ret++;
 846	if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
 847		ret++;
 848	return ret;
 849}
 850
 851static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
 852{
 853	return list_empty(&sci->sc_dirty_files) &&
 854		!test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
 855		sci->sc_nfreesegs == 0 &&
 856		(!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
 857}
 858
 859static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
 860{
 861	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 862	int ret = 0;
 863
 864	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
 865		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
 866
 867	spin_lock(&nilfs->ns_inode_lock);
 868	if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
 869		ret++;
 870
 871	spin_unlock(&nilfs->ns_inode_lock);
 872	return ret;
 873}
 874
 875static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
 876{
 877	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 878
 879	nilfs_mdt_clear_dirty(sci->sc_root->ifile);
 880	nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
 881	nilfs_mdt_clear_dirty(nilfs->ns_sufile);
 882	nilfs_mdt_clear_dirty(nilfs->ns_dat);
 883}
 884
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 885static void nilfs_fill_in_file_bmap(struct inode *ifile,
 886				    struct nilfs_inode_info *ii)
 887
 888{
 889	struct buffer_head *ibh;
 890	struct nilfs_inode *raw_inode;
 891
 892	if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
 893		ibh = ii->i_bh;
 894		BUG_ON(!ibh);
 895		raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
 896						  ibh);
 897		nilfs_bmap_write(ii->i_bmap, raw_inode);
 898		nilfs_ifile_unmap_inode(raw_inode);
 899	}
 900}
 901
 902static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
 903{
 904	struct nilfs_inode_info *ii;
 905
 906	list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
 907		nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
 908		set_bit(NILFS_I_COLLECTED, &ii->i_state);
 909	}
 910}
 911
 912/**
 913 * nilfs_write_root_mdt_inode - export root metadata inode information to
 914 *                              the on-disk inode
 915 * @inode:     inode object of the root metadata file
 916 * @raw_inode: on-disk inode
 917 *
 918 * nilfs_write_root_mdt_inode() writes inode information and bmap data of
 919 * @inode to the inode area of the metadata file allocated on the super root
 920 * block created to finalize the log.  Since super root blocks are configured
 921 * each time, this function zero-fills the unused area of @raw_inode.
 922 */
 923static void nilfs_write_root_mdt_inode(struct inode *inode,
 924				       struct nilfs_inode *raw_inode)
 925{
 926	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 927
 928	nilfs_write_inode_common(inode, raw_inode);
 929
 930	/* zero-fill unused portion of raw_inode */
 931	raw_inode->i_xattr = 0;
 932	raw_inode->i_pad = 0;
 933	memset((void *)raw_inode + sizeof(*raw_inode), 0,
 934	       nilfs->ns_inode_size - sizeof(*raw_inode));
 935
 936	nilfs_bmap_write(NILFS_I(inode)->i_bmap, raw_inode);
 937}
 938
 939static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 940					     struct the_nilfs *nilfs)
 941{
 942	struct buffer_head *bh_sr;
 943	struct nilfs_super_root *raw_sr;
 944	unsigned int isz, srsz;
 945
 946	bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
 947
 948	lock_buffer(bh_sr);
 949	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
 950	isz = nilfs->ns_inode_size;
 951	srsz = NILFS_SR_BYTES(isz);
 952
 953	raw_sr->sr_sum = 0;  /* Ensure initialization within this update */
 954	raw_sr->sr_bytes = cpu_to_le16(srsz);
 955	raw_sr->sr_nongc_ctime
 956		= cpu_to_le64(nilfs_doing_gc() ?
 957			      nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
 958	raw_sr->sr_flags = 0;
 959
 960	nilfs_write_root_mdt_inode(nilfs->ns_dat, (void *)raw_sr +
 961				   NILFS_SR_DAT_OFFSET(isz));
 962	nilfs_write_root_mdt_inode(nilfs->ns_cpfile, (void *)raw_sr +
 963				   NILFS_SR_CPFILE_OFFSET(isz));
 964	nilfs_write_root_mdt_inode(nilfs->ns_sufile, (void *)raw_sr +
 965				   NILFS_SR_SUFILE_OFFSET(isz));
 966
 967	memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
 968	set_buffer_uptodate(bh_sr);
 969	unlock_buffer(bh_sr);
 970}
 971
 972static void nilfs_redirty_inodes(struct list_head *head)
 973{
 974	struct nilfs_inode_info *ii;
 975
 976	list_for_each_entry(ii, head, i_dirty) {
 977		if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
 978			clear_bit(NILFS_I_COLLECTED, &ii->i_state);
 979	}
 980}
 981
 982static void nilfs_drop_collected_inodes(struct list_head *head)
 983{
 984	struct nilfs_inode_info *ii;
 985
 986	list_for_each_entry(ii, head, i_dirty) {
 987		if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
 988			continue;
 989
 990		clear_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 991		set_bit(NILFS_I_UPDATED, &ii->i_state);
 992	}
 993}
 994
 995static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
 996				       struct inode *inode,
 997				       struct list_head *listp,
 998				       int (*collect)(struct nilfs_sc_info *,
 999						      struct buffer_head *,
1000						      struct inode *))
1001{
1002	struct buffer_head *bh, *n;
1003	int err = 0;
1004
1005	if (collect) {
1006		list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
1007			list_del_init(&bh->b_assoc_buffers);
1008			err = collect(sci, bh, inode);
1009			brelse(bh);
1010			if (unlikely(err))
1011				goto dispose_buffers;
1012		}
1013		return 0;
1014	}
1015
1016 dispose_buffers:
1017	while (!list_empty(listp)) {
1018		bh = list_first_entry(listp, struct buffer_head,
1019				      b_assoc_buffers);
1020		list_del_init(&bh->b_assoc_buffers);
1021		brelse(bh);
1022	}
1023	return err;
1024}
1025
1026static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
1027{
1028	/* Remaining number of blocks within segment buffer */
1029	return sci->sc_segbuf_nblocks -
1030		(sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
1031}
1032
1033static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
1034				   struct inode *inode,
1035				   const struct nilfs_sc_operations *sc_ops)
1036{
1037	LIST_HEAD(data_buffers);
1038	LIST_HEAD(node_buffers);
1039	int err;
1040
1041	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1042		size_t n, rest = nilfs_segctor_buffer_rest(sci);
1043
1044		n = nilfs_lookup_dirty_data_buffers(
1045			inode, &data_buffers, rest + 1, 0, LLONG_MAX);
1046		if (n > rest) {
1047			err = nilfs_segctor_apply_buffers(
1048				sci, inode, &data_buffers,
1049				sc_ops->collect_data);
1050			BUG_ON(!err); /* always receive -E2BIG or true error */
1051			goto break_or_fail;
1052		}
1053	}
1054	nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
1055
1056	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
1057		err = nilfs_segctor_apply_buffers(
1058			sci, inode, &data_buffers, sc_ops->collect_data);
1059		if (unlikely(err)) {
1060			/* dispose node list */
1061			nilfs_segctor_apply_buffers(
1062				sci, inode, &node_buffers, NULL);
1063			goto break_or_fail;
1064		}
1065		sci->sc_stage.flags |= NILFS_CF_NODE;
1066	}
1067	/* Collect node */
1068	err = nilfs_segctor_apply_buffers(
1069		sci, inode, &node_buffers, sc_ops->collect_node);
1070	if (unlikely(err))
1071		goto break_or_fail;
1072
1073	nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1074	err = nilfs_segctor_apply_buffers(
1075		sci, inode, &node_buffers, sc_ops->collect_bmap);
1076	if (unlikely(err))
1077		goto break_or_fail;
1078
1079	nilfs_segctor_end_finfo(sci, inode);
1080	sci->sc_stage.flags &= ~NILFS_CF_NODE;
1081
1082 break_or_fail:
1083	return err;
1084}
1085
1086static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1087					 struct inode *inode)
1088{
1089	LIST_HEAD(data_buffers);
1090	size_t n, rest = nilfs_segctor_buffer_rest(sci);
1091	int err;
1092
1093	n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1094					    sci->sc_dsync_start,
1095					    sci->sc_dsync_end);
1096
1097	err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1098					  nilfs_collect_file_data);
1099	if (!err) {
1100		nilfs_segctor_end_finfo(sci, inode);
1101		BUG_ON(n > rest);
1102		/* always receive -E2BIG or true error if n > rest */
1103	}
1104	return err;
1105}
1106
1107/**
1108 * nilfs_free_segments - free the segments given by an array of segment numbers
1109 * @nilfs:   nilfs object
1110 * @segnumv: array of segment numbers to be freed
1111 * @nsegs:   number of segments to be freed in @segnumv
1112 *
1113 * nilfs_free_segments() wraps nilfs_sufile_freev() and
1114 * nilfs_sufile_cancel_freev(), and edits the segment usage metadata file
1115 * (sufile) to free all segments given by @segnumv and @nsegs at once.  If
1116 * it fails midway, it cancels the changes so that none of the segments are
1117 * freed.  If @nsegs is 0, this function does nothing.
1118 *
1119 * The freeing of segments is not finalized until the writing of a log with
1120 * a super root block containing this sufile change is complete, and it can
1121 * be canceled with nilfs_sufile_cancel_freev() until then.
1122 *
1123 * Return: 0 on success, or the following negative error code on failure.
1124 * * %-EINVAL	- Invalid segment number.
1125 * * %-EIO	- I/O error (including metadata corruption).
1126 * * %-ENOMEM	- Insufficient memory available.
1127 */
1128static int nilfs_free_segments(struct the_nilfs *nilfs, __u64 *segnumv,
1129			       size_t nsegs)
1130{
1131	size_t ndone;
1132	int ret;
1133
1134	if (!nsegs)
1135		return 0;
1136
1137	ret = nilfs_sufile_freev(nilfs->ns_sufile, segnumv, nsegs, &ndone);
1138	if (unlikely(ret)) {
1139		nilfs_sufile_cancel_freev(nilfs->ns_sufile, segnumv, ndone,
1140					  NULL);
1141		/*
1142		 * If a segment usage of the segments to be freed is in a
1143		 * hole block, nilfs_sufile_freev() will return -ENOENT.
1144		 * In this case, -EINVAL should be returned to the caller
1145		 * since there is something wrong with the given segment
1146		 * number array.  This error can only occur during GC, so
1147		 * there is no need to worry about it propagating to other
1148		 * callers (such as fsync).
1149		 */
1150		if (ret == -ENOENT) {
1151			nilfs_err(nilfs->ns_sb,
1152				  "The segment usage entry %llu to be freed is invalid (in a hole)",
1153				  (unsigned long long)segnumv[ndone]);
1154			ret = -EINVAL;
1155		}
1156	}
1157	return ret;
1158}
1159
1160static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1161{
1162	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1163	struct list_head *head;
1164	struct nilfs_inode_info *ii;
 
1165	int err = 0;
1166
1167	switch (nilfs_sc_cstage_get(sci)) {
1168	case NILFS_ST_INIT:
1169		/* Pre-processes */
1170		sci->sc_stage.flags = 0;
1171
1172		if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1173			sci->sc_nblk_inc = 0;
1174			sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1175			if (mode == SC_LSEG_DSYNC) {
1176				nilfs_sc_cstage_set(sci, NILFS_ST_DSYNC);
1177				goto dsync_mode;
1178			}
1179		}
1180
1181		sci->sc_stage.dirty_file_ptr = NULL;
1182		sci->sc_stage.gc_inode_ptr = NULL;
1183		if (mode == SC_FLUSH_DAT) {
1184			nilfs_sc_cstage_set(sci, NILFS_ST_DAT);
1185			goto dat_stage;
1186		}
1187		nilfs_sc_cstage_inc(sci);
1188		fallthrough;
1189	case NILFS_ST_GC:
1190		if (nilfs_doing_gc()) {
1191			head = &sci->sc_gc_inodes;
1192			ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1193						head, i_dirty);
1194			list_for_each_entry_continue(ii, head, i_dirty) {
1195				err = nilfs_segctor_scan_file(
1196					sci, &ii->vfs_inode,
1197					&nilfs_sc_file_ops);
1198				if (unlikely(err)) {
1199					sci->sc_stage.gc_inode_ptr = list_entry(
1200						ii->i_dirty.prev,
1201						struct nilfs_inode_info,
1202						i_dirty);
1203					goto break_or_fail;
1204				}
1205				set_bit(NILFS_I_COLLECTED, &ii->i_state);
1206			}
1207			sci->sc_stage.gc_inode_ptr = NULL;
1208		}
1209		nilfs_sc_cstage_inc(sci);
1210		fallthrough;
1211	case NILFS_ST_FILE:
1212		head = &sci->sc_dirty_files;
1213		ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1214					i_dirty);
1215		list_for_each_entry_continue(ii, head, i_dirty) {
1216			clear_bit(NILFS_I_DIRTY, &ii->i_state);
1217
1218			err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1219						      &nilfs_sc_file_ops);
1220			if (unlikely(err)) {
1221				sci->sc_stage.dirty_file_ptr =
1222					list_entry(ii->i_dirty.prev,
1223						   struct nilfs_inode_info,
1224						   i_dirty);
1225				goto break_or_fail;
1226			}
1227			/* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1228			/* XXX: required ? */
1229		}
1230		sci->sc_stage.dirty_file_ptr = NULL;
1231		if (mode == SC_FLUSH_FILE) {
1232			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1233			return 0;
1234		}
1235		nilfs_sc_cstage_inc(sci);
1236		sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1237		fallthrough;
1238	case NILFS_ST_IFILE:
1239		err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1240					      &nilfs_sc_file_ops);
1241		if (unlikely(err))
1242			break;
1243		nilfs_sc_cstage_inc(sci);
1244		/* Creating a checkpoint */
1245		err = nilfs_cpfile_create_checkpoint(nilfs->ns_cpfile,
1246						     nilfs->ns_cno);
1247		if (unlikely(err))
1248			break;
1249		fallthrough;
1250	case NILFS_ST_CPFILE:
1251		err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1252					      &nilfs_sc_file_ops);
1253		if (unlikely(err))
1254			break;
1255		nilfs_sc_cstage_inc(sci);
1256		fallthrough;
1257	case NILFS_ST_SUFILE:
1258		err = nilfs_free_segments(nilfs, sci->sc_freesegs,
1259					  sci->sc_nfreesegs);
1260		if (unlikely(err))
 
 
 
1261			break;
 
1262		sci->sc_stage.flags |= NILFS_CF_SUFREED;
1263
1264		err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1265					      &nilfs_sc_file_ops);
1266		if (unlikely(err))
1267			break;
1268		nilfs_sc_cstage_inc(sci);
1269		fallthrough;
1270	case NILFS_ST_DAT:
1271 dat_stage:
1272		err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1273					      &nilfs_sc_dat_ops);
1274		if (unlikely(err))
1275			break;
1276		if (mode == SC_FLUSH_DAT) {
1277			nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1278			return 0;
1279		}
1280		nilfs_sc_cstage_inc(sci);
1281		fallthrough;
1282	case NILFS_ST_SR:
1283		if (mode == SC_LSEG_SR) {
1284			/* Appending a super root */
1285			err = nilfs_segctor_add_super_root(sci);
1286			if (unlikely(err))
1287				break;
1288		}
1289		/* End of a logical segment */
1290		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1291		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1292		return 0;
1293	case NILFS_ST_DSYNC:
1294 dsync_mode:
1295		sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1296		ii = sci->sc_dsync_inode;
1297		if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1298			break;
1299
1300		err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1301		if (unlikely(err))
1302			break;
1303		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1304		nilfs_sc_cstage_set(sci, NILFS_ST_DONE);
1305		return 0;
1306	case NILFS_ST_DONE:
1307		return 0;
1308	default:
1309		BUG();
1310	}
1311
1312 break_or_fail:
1313	return err;
1314}
1315
1316/**
1317 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1318 * @sci: nilfs_sc_info
1319 * @nilfs: nilfs object
1320 */
1321static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1322					    struct the_nilfs *nilfs)
1323{
1324	struct nilfs_segment_buffer *segbuf, *prev;
1325	__u64 nextnum;
1326	int err, alloc = 0;
1327
1328	segbuf = nilfs_segbuf_new(sci->sc_super);
1329	if (unlikely(!segbuf))
1330		return -ENOMEM;
1331
1332	if (list_empty(&sci->sc_write_logs)) {
1333		nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1334				 nilfs->ns_pseg_offset, nilfs);
1335		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1336			nilfs_shift_to_next_segment(nilfs);
1337			nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1338		}
1339
1340		segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1341		nextnum = nilfs->ns_nextnum;
1342
1343		if (nilfs->ns_segnum == nilfs->ns_nextnum)
1344			/* Start from the head of a new full segment */
1345			alloc++;
1346	} else {
1347		/* Continue logs */
1348		prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1349		nilfs_segbuf_map_cont(segbuf, prev);
1350		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1351		nextnum = prev->sb_nextnum;
1352
1353		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1354			nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1355			segbuf->sb_sum.seg_seq++;
1356			alloc++;
1357		}
1358	}
1359
1360	err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1361	if (err)
1362		goto failed;
1363
1364	if (alloc) {
1365		err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1366		if (err)
1367			goto failed;
1368	}
1369	nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1370
1371	BUG_ON(!list_empty(&sci->sc_segbufs));
1372	list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1373	sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1374	return 0;
1375
1376 failed:
1377	nilfs_segbuf_free(segbuf);
1378	return err;
1379}
1380
1381static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1382					 struct the_nilfs *nilfs, int nadd)
1383{
1384	struct nilfs_segment_buffer *segbuf, *prev;
1385	struct inode *sufile = nilfs->ns_sufile;
1386	__u64 nextnextnum;
1387	LIST_HEAD(list);
1388	int err, ret, i;
1389
1390	prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1391	/*
1392	 * Since the segment specified with nextnum might be allocated during
1393	 * the previous construction, the buffer including its segusage may
1394	 * not be dirty.  The following call ensures that the buffer is dirty
1395	 * and will pin the buffer on memory until the sufile is written.
1396	 */
1397	err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1398	if (unlikely(err))
1399		return err;
1400
1401	for (i = 0; i < nadd; i++) {
1402		/* extend segment info */
1403		err = -ENOMEM;
1404		segbuf = nilfs_segbuf_new(sci->sc_super);
1405		if (unlikely(!segbuf))
1406			goto failed;
1407
1408		/* map this buffer to region of segment on-disk */
1409		nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1410		sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1411
1412		/* allocate the next next full segment */
1413		err = nilfs_sufile_alloc(sufile, &nextnextnum);
1414		if (unlikely(err))
1415			goto failed_segbuf;
1416
1417		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1418		nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1419
1420		list_add_tail(&segbuf->sb_list, &list);
1421		prev = segbuf;
1422	}
1423	list_splice_tail(&list, &sci->sc_segbufs);
1424	return 0;
1425
1426 failed_segbuf:
1427	nilfs_segbuf_free(segbuf);
1428 failed:
1429	list_for_each_entry(segbuf, &list, sb_list) {
1430		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1431		WARN_ON(ret); /* never fails */
1432	}
1433	nilfs_destroy_logs(&list);
1434	return err;
1435}
1436
1437static void nilfs_free_incomplete_logs(struct list_head *logs,
1438				       struct the_nilfs *nilfs)
1439{
1440	struct nilfs_segment_buffer *segbuf, *prev;
1441	struct inode *sufile = nilfs->ns_sufile;
1442	int ret;
1443
1444	segbuf = NILFS_FIRST_SEGBUF(logs);
1445	if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1446		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1447		WARN_ON(ret); /* never fails */
1448	}
1449	if (atomic_read(&segbuf->sb_err)) {
1450		/* Case 1: The first segment failed */
1451		if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1452			/*
1453			 * Case 1a:  Partial segment appended into an existing
1454			 * segment
1455			 */
1456			nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1457						segbuf->sb_fseg_end);
1458		else /* Case 1b:  New full segment */
1459			set_nilfs_discontinued(nilfs);
1460	}
1461
1462	prev = segbuf;
1463	list_for_each_entry_continue(segbuf, logs, sb_list) {
1464		if (prev->sb_nextnum != segbuf->sb_nextnum) {
1465			ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1466			WARN_ON(ret); /* never fails */
1467		}
1468		if (atomic_read(&segbuf->sb_err) &&
1469		    segbuf->sb_segnum != nilfs->ns_nextnum)
1470			/* Case 2: extended segment (!= next) failed */
1471			nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1472		prev = segbuf;
1473	}
1474}
1475
1476static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1477					  struct inode *sufile)
1478{
1479	struct nilfs_segment_buffer *segbuf;
1480	unsigned long live_blocks;
1481	int ret;
1482
1483	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1484		live_blocks = segbuf->sb_sum.nblocks +
1485			(segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1486		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1487						     live_blocks,
1488						     sci->sc_seg_ctime);
1489		WARN_ON(ret); /* always succeed because the segusage is dirty */
1490	}
1491}
1492
1493static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1494{
1495	struct nilfs_segment_buffer *segbuf;
1496	int ret;
1497
1498	segbuf = NILFS_FIRST_SEGBUF(logs);
1499	ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1500					     segbuf->sb_pseg_start -
1501					     segbuf->sb_fseg_start, 0);
1502	WARN_ON(ret); /* always succeed because the segusage is dirty */
1503
1504	list_for_each_entry_continue(segbuf, logs, sb_list) {
1505		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1506						     0, 0);
1507		WARN_ON(ret); /* always succeed */
1508	}
1509}
1510
1511static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1512					    struct nilfs_segment_buffer *last,
1513					    struct inode *sufile)
1514{
1515	struct nilfs_segment_buffer *segbuf = last;
1516	int ret;
1517
1518	list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1519		sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1520		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1521		WARN_ON(ret);
1522	}
1523	nilfs_truncate_logs(&sci->sc_segbufs, last);
1524}
1525
1526
1527static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1528				 struct the_nilfs *nilfs, int mode)
1529{
1530	struct nilfs_cstage prev_stage = sci->sc_stage;
1531	int err, nadd = 1;
1532
1533	/* Collection retry loop */
1534	for (;;) {
1535		sci->sc_nblk_this_inc = 0;
1536		sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1537
1538		err = nilfs_segctor_reset_segment_buffer(sci);
1539		if (unlikely(err))
1540			goto failed;
1541
1542		err = nilfs_segctor_collect_blocks(sci, mode);
1543		sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1544		if (!err)
1545			break;
1546
1547		if (unlikely(err != -E2BIG))
1548			goto failed;
1549
1550		/* The current segment is filled up */
1551		if (mode != SC_LSEG_SR ||
1552		    nilfs_sc_cstage_get(sci) < NILFS_ST_CPFILE)
1553			break;
1554
1555		nilfs_clear_logs(&sci->sc_segbufs);
1556
1557		if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1558			err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1559							sci->sc_freesegs,
1560							sci->sc_nfreesegs,
1561							NULL);
1562			WARN_ON(err); /* do not happen */
1563			sci->sc_stage.flags &= ~NILFS_CF_SUFREED;
1564		}
1565
1566		err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1567		if (unlikely(err))
1568			return err;
1569
1570		nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1571		sci->sc_stage = prev_stage;
1572	}
1573	nilfs_segctor_zeropad_segsum(sci);
1574	nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1575	return 0;
1576
1577 failed:
1578	return err;
1579}
1580
1581static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1582				      struct buffer_head *new_bh)
1583{
1584	BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1585
1586	list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1587	/* The caller must release old_bh */
1588}
1589
1590static int
1591nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1592				     struct nilfs_segment_buffer *segbuf,
1593				     int mode)
1594{
1595	struct inode *inode = NULL;
1596	sector_t blocknr;
1597	unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1598	unsigned long nblocks = 0, ndatablk = 0;
1599	const struct nilfs_sc_operations *sc_op = NULL;
1600	struct nilfs_segsum_pointer ssp;
1601	struct nilfs_finfo *finfo = NULL;
1602	union nilfs_binfo binfo;
1603	struct buffer_head *bh, *bh_org;
1604	ino_t ino = 0;
1605	int err = 0;
1606
1607	if (!nfinfo)
1608		goto out;
1609
1610	blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1611	ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1612	ssp.offset = sizeof(struct nilfs_segment_summary);
1613
1614	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1615		if (bh == segbuf->sb_super_root)
1616			break;
1617		if (!finfo) {
1618			finfo =	nilfs_segctor_map_segsum_entry(
1619				sci, &ssp, sizeof(*finfo));
1620			ino = le64_to_cpu(finfo->fi_ino);
1621			nblocks = le32_to_cpu(finfo->fi_nblocks);
1622			ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1623
1624			inode = bh->b_folio->mapping->host;
1625
1626			if (mode == SC_LSEG_DSYNC)
1627				sc_op = &nilfs_sc_dsync_ops;
1628			else if (ino == NILFS_DAT_INO)
1629				sc_op = &nilfs_sc_dat_ops;
1630			else /* file blocks */
1631				sc_op = &nilfs_sc_file_ops;
1632		}
1633		bh_org = bh;
1634		get_bh(bh_org);
1635		err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1636					&binfo);
1637		if (bh != bh_org)
1638			nilfs_list_replace_buffer(bh_org, bh);
1639		brelse(bh_org);
1640		if (unlikely(err))
1641			goto failed_bmap;
1642
1643		if (ndatablk > 0)
1644			sc_op->write_data_binfo(sci, &ssp, &binfo);
1645		else
1646			sc_op->write_node_binfo(sci, &ssp, &binfo);
1647
1648		blocknr++;
1649		if (--nblocks == 0) {
1650			finfo = NULL;
1651			if (--nfinfo == 0)
1652				break;
1653		} else if (ndatablk > 0)
1654			ndatablk--;
1655	}
1656 out:
1657	return 0;
1658
1659 failed_bmap:
1660	return err;
1661}
1662
1663static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1664{
1665	struct nilfs_segment_buffer *segbuf;
1666	int err;
1667
1668	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1669		err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1670		if (unlikely(err))
1671			return err;
1672		nilfs_segbuf_fill_in_segsum(segbuf);
1673	}
1674	return 0;
1675}
1676
1677static void nilfs_begin_folio_io(struct folio *folio)
1678{
1679	if (!folio || folio_test_writeback(folio))
1680		/*
1681		 * For split b-tree node pages, this function may be called
1682		 * twice.  We ignore the 2nd or later calls by this check.
1683		 */
1684		return;
1685
1686	folio_lock(folio);
1687	folio_clear_dirty_for_io(folio);
1688	folio_start_writeback(folio);
1689	folio_unlock(folio);
1690}
1691
1692/**
1693 * nilfs_prepare_write_logs - prepare to write logs
1694 * @logs: logs to prepare for writing
1695 * @seed: checksum seed value
1696 *
1697 * nilfs_prepare_write_logs() adds checksums and prepares the block
1698 * buffers/folios for writing logs.  In order to stabilize folios of
1699 * memory-mapped file blocks by putting them in writeback state before
1700 * calculating the checksums, first prepare to write payload blocks other
1701 * than segment summary and super root blocks in which the checksums will
1702 * be embedded.
1703 */
1704static void nilfs_prepare_write_logs(struct list_head *logs, u32 seed)
1705{
1706	struct nilfs_segment_buffer *segbuf;
1707	struct folio *bd_folio = NULL, *fs_folio = NULL;
1708	struct buffer_head *bh;
1709
1710	/* Prepare to write payload blocks */
1711	list_for_each_entry(segbuf, logs, sb_list) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1712		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1713				    b_assoc_buffers) {
1714			if (bh == segbuf->sb_super_root)
 
 
 
 
 
 
 
1715				break;
 
1716			set_buffer_async_write(bh);
1717			if (bh->b_folio != fs_folio) {
1718				nilfs_begin_folio_io(fs_folio);
1719				fs_folio = bh->b_folio;
1720			}
1721		}
1722	}
1723	nilfs_begin_folio_io(fs_folio);
1724
1725	nilfs_add_checksums_on_logs(logs, seed);
1726
1727	/* Prepare to write segment summary blocks */
1728	list_for_each_entry(segbuf, logs, sb_list) {
1729		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1730				    b_assoc_buffers) {
1731			mark_buffer_dirty(bh);
1732			if (bh->b_folio == bd_folio)
1733				continue;
1734			if (bd_folio) {
1735				folio_lock(bd_folio);
1736				folio_wait_writeback(bd_folio);
1737				folio_clear_dirty_for_io(bd_folio);
1738				folio_start_writeback(bd_folio);
1739				folio_unlock(bd_folio);
1740			}
1741			bd_folio = bh->b_folio;
1742		}
1743	}
1744
1745	/* Prepare to write super root block */
1746	bh = NILFS_LAST_SEGBUF(logs)->sb_super_root;
1747	if (bh) {
1748		mark_buffer_dirty(bh);
1749		if (bh->b_folio != bd_folio) {
1750			folio_lock(bd_folio);
1751			folio_wait_writeback(bd_folio);
1752			folio_clear_dirty_for_io(bd_folio);
1753			folio_start_writeback(bd_folio);
1754			folio_unlock(bd_folio);
1755			bd_folio = bh->b_folio;
1756		}
1757	}
1758
1759	if (bd_folio) {
1760		folio_lock(bd_folio);
1761		folio_wait_writeback(bd_folio);
1762		folio_clear_dirty_for_io(bd_folio);
1763		folio_start_writeback(bd_folio);
1764		folio_unlock(bd_folio);
1765	}
 
1766}
1767
1768static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1769			       struct the_nilfs *nilfs)
1770{
1771	int ret;
1772
1773	ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1774	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1775	return ret;
1776}
1777
1778static void nilfs_end_folio_io(struct folio *folio, int err)
1779{
1780	if (!folio)
1781		return;
1782
1783	if (buffer_nilfs_node(folio_buffers(folio)) &&
1784			!folio_test_writeback(folio)) {
1785		/*
1786		 * For b-tree node pages, this function may be called twice
1787		 * or more because they might be split in a segment.
1788		 */
1789		if (folio_test_dirty(folio)) {
1790			/*
1791			 * For pages holding split b-tree node buffers, dirty
1792			 * flag on the buffers may be cleared discretely.
1793			 * In that case, the page is once redirtied for
1794			 * remaining buffers, and it must be cancelled if
1795			 * all the buffers get cleaned later.
1796			 */
1797			folio_lock(folio);
1798			if (nilfs_folio_buffers_clean(folio))
1799				__nilfs_clear_folio_dirty(folio);
1800			folio_unlock(folio);
1801		}
1802		return;
1803	}
1804
1805	if (err || !nilfs_folio_buffers_clean(folio))
 
 
 
 
1806		filemap_dirty_folio(folio->mapping, folio);
 
 
1807
1808	folio_end_writeback(folio);
1809}
1810
1811static void nilfs_abort_logs(struct list_head *logs, int err)
1812{
1813	struct nilfs_segment_buffer *segbuf;
1814	struct folio *bd_folio = NULL, *fs_folio = NULL;
1815	struct buffer_head *bh;
1816
1817	if (list_empty(logs))
1818		return;
1819
1820	list_for_each_entry(segbuf, logs, sb_list) {
1821		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1822				    b_assoc_buffers) {
1823			clear_buffer_uptodate(bh);
1824			if (bh->b_folio != bd_folio) {
1825				if (bd_folio)
1826					folio_end_writeback(bd_folio);
1827				bd_folio = bh->b_folio;
1828			}
1829		}
1830
1831		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1832				    b_assoc_buffers) {
1833			if (bh == segbuf->sb_super_root) {
1834				clear_buffer_uptodate(bh);
1835				if (bh->b_folio != bd_folio) {
1836					folio_end_writeback(bd_folio);
1837					bd_folio = bh->b_folio;
1838				}
1839				break;
1840			}
1841			clear_buffer_async_write(bh);
1842			if (bh->b_folio != fs_folio) {
1843				nilfs_end_folio_io(fs_folio, err);
1844				fs_folio = bh->b_folio;
1845			}
1846		}
1847	}
1848	if (bd_folio)
1849		folio_end_writeback(bd_folio);
1850
1851	nilfs_end_folio_io(fs_folio, err);
1852}
1853
1854static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1855					     struct the_nilfs *nilfs, int err)
1856{
1857	LIST_HEAD(logs);
1858	int ret;
1859
1860	list_splice_tail_init(&sci->sc_write_logs, &logs);
1861	ret = nilfs_wait_on_logs(&logs);
1862	nilfs_abort_logs(&logs, ret ? : err);
1863
1864	list_splice_tail_init(&sci->sc_segbufs, &logs);
1865	if (list_empty(&logs))
1866		return; /* if the first segment buffer preparation failed */
1867
1868	nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1869	nilfs_free_incomplete_logs(&logs, nilfs);
1870
1871	if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1872		ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1873						sci->sc_freesegs,
1874						sci->sc_nfreesegs,
1875						NULL);
1876		WARN_ON(ret); /* do not happen */
1877	}
1878
1879	nilfs_destroy_logs(&logs);
1880}
1881
1882static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1883				   struct nilfs_segment_buffer *segbuf)
1884{
1885	nilfs->ns_segnum = segbuf->sb_segnum;
1886	nilfs->ns_nextnum = segbuf->sb_nextnum;
1887	nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1888		+ segbuf->sb_sum.nblocks;
1889	nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1890	nilfs->ns_ctime = segbuf->sb_sum.ctime;
1891}
1892
1893static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1894{
1895	struct nilfs_segment_buffer *segbuf;
1896	struct folio *bd_folio = NULL, *fs_folio = NULL;
1897	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1898	int update_sr = false;
1899
1900	list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1901		struct buffer_head *bh;
1902
1903		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1904				    b_assoc_buffers) {
1905			set_buffer_uptodate(bh);
1906			clear_buffer_dirty(bh);
1907			if (bh->b_folio != bd_folio) {
1908				if (bd_folio)
1909					folio_end_writeback(bd_folio);
1910				bd_folio = bh->b_folio;
1911			}
1912		}
1913		/*
1914		 * We assume that the buffers which belong to the same folio
1915		 * continue over the buffer list.
1916		 * Under this assumption, the last BHs of folios is
1917		 * identifiable by the discontinuity of bh->b_folio
1918		 * (folio != fs_folio).
1919		 *
1920		 * For B-tree node blocks, however, this assumption is not
1921		 * guaranteed.  The cleanup code of B-tree node folios needs
1922		 * special care.
1923		 */
1924		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1925				    b_assoc_buffers) {
1926			const unsigned long set_bits = BIT(BH_Uptodate);
1927			const unsigned long clear_bits =
1928				(BIT(BH_Dirty) | BIT(BH_Async_Write) |
1929				 BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |
1930				 BIT(BH_NILFS_Redirected));
1931
1932			if (bh == segbuf->sb_super_root) {
1933				set_buffer_uptodate(bh);
1934				clear_buffer_dirty(bh);
1935				if (bh->b_folio != bd_folio) {
1936					folio_end_writeback(bd_folio);
1937					bd_folio = bh->b_folio;
1938				}
1939				update_sr = true;
1940				break;
1941			}
1942			set_mask_bits(&bh->b_state, clear_bits, set_bits);
1943			if (bh->b_folio != fs_folio) {
1944				nilfs_end_folio_io(fs_folio, 0);
1945				fs_folio = bh->b_folio;
1946			}
1947		}
1948
1949		if (!nilfs_segbuf_simplex(segbuf)) {
1950			if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1951				set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1952				sci->sc_lseg_stime = jiffies;
1953			}
1954			if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1955				clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1956		}
1957	}
1958	/*
1959	 * Since folios may continue over multiple segment buffers,
1960	 * end of the last folio must be checked outside of the loop.
1961	 */
1962	if (bd_folio)
1963		folio_end_writeback(bd_folio);
1964
1965	nilfs_end_folio_io(fs_folio, 0);
1966
1967	nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1968
1969	if (nilfs_doing_gc())
1970		nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1971	else
1972		nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1973
1974	sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1975
1976	segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1977	nilfs_set_next_segment(nilfs, segbuf);
1978
1979	if (update_sr) {
1980		nilfs->ns_flushed_device = 0;
1981		nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1982				       segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1983
1984		clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1985		clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1986		set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1987		nilfs_segctor_clear_metadata_dirty(sci);
1988	} else
1989		clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1990}
1991
1992static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1993{
1994	int ret;
1995
1996	ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1997	if (!ret) {
1998		nilfs_segctor_complete_write(sci);
1999		nilfs_destroy_logs(&sci->sc_write_logs);
2000	}
2001	return ret;
2002}
2003
2004static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
2005					     struct the_nilfs *nilfs)
2006{
2007	struct nilfs_inode_info *ii, *n;
2008	struct inode *ifile = sci->sc_root->ifile;
2009
2010	spin_lock(&nilfs->ns_inode_lock);
2011 retry:
2012	list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
2013		if (!ii->i_bh) {
2014			struct buffer_head *ibh;
2015			int err;
2016
2017			spin_unlock(&nilfs->ns_inode_lock);
2018			err = nilfs_ifile_get_inode_block(
2019				ifile, ii->vfs_inode.i_ino, &ibh);
2020			if (unlikely(err)) {
2021				nilfs_warn(sci->sc_super,
2022					   "log writer: error %d getting inode block (ino=%lu)",
2023					   err, ii->vfs_inode.i_ino);
2024				return err;
2025			}
2026			spin_lock(&nilfs->ns_inode_lock);
2027			if (likely(!ii->i_bh))
2028				ii->i_bh = ibh;
2029			else
2030				brelse(ibh);
2031			goto retry;
2032		}
2033
2034		// Always redirty the buffer to avoid race condition
2035		mark_buffer_dirty(ii->i_bh);
2036		nilfs_mdt_mark_dirty(ifile);
2037
2038		clear_bit(NILFS_I_QUEUED, &ii->i_state);
2039		set_bit(NILFS_I_BUSY, &ii->i_state);
2040		list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
2041	}
2042	spin_unlock(&nilfs->ns_inode_lock);
2043
2044	return 0;
2045}
2046
2047static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
2048					     struct the_nilfs *nilfs)
2049{
2050	struct nilfs_inode_info *ii, *n;
2051	int during_mount = !(sci->sc_super->s_flags & SB_ACTIVE);
2052	int defer_iput = false;
2053
2054	spin_lock(&nilfs->ns_inode_lock);
2055	list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
2056		if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
2057		    test_bit(NILFS_I_DIRTY, &ii->i_state))
2058			continue;
2059
2060		clear_bit(NILFS_I_BUSY, &ii->i_state);
2061		brelse(ii->i_bh);
2062		ii->i_bh = NULL;
2063		list_del_init(&ii->i_dirty);
2064		if (!ii->vfs_inode.i_nlink || during_mount) {
2065			/*
2066			 * Defer calling iput() to avoid deadlocks if
2067			 * i_nlink == 0 or mount is not yet finished.
2068			 */
2069			list_add_tail(&ii->i_dirty, &sci->sc_iput_queue);
2070			defer_iput = true;
2071		} else {
2072			spin_unlock(&nilfs->ns_inode_lock);
2073			iput(&ii->vfs_inode);
2074			spin_lock(&nilfs->ns_inode_lock);
2075		}
2076	}
2077	spin_unlock(&nilfs->ns_inode_lock);
2078
2079	if (defer_iput)
2080		schedule_work(&sci->sc_iput_work);
2081}
2082
2083/*
2084 * Main procedure of segment constructor
2085 */
2086static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
2087{
2088	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2089	int err;
2090
2091	if (sb_rdonly(sci->sc_super))
2092		return -EROFS;
2093
2094	nilfs_sc_cstage_set(sci, NILFS_ST_INIT);
2095	sci->sc_cno = nilfs->ns_cno;
2096
2097	err = nilfs_segctor_collect_dirty_files(sci, nilfs);
2098	if (unlikely(err))
2099		goto out;
2100
2101	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
2102		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
2103
2104	if (nilfs_segctor_clean(sci))
2105		goto out;
2106
2107	do {
2108		sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
2109
2110		err = nilfs_segctor_begin_construction(sci, nilfs);
2111		if (unlikely(err))
2112			goto failed;
2113
2114		/* Update time stamp */
2115		sci->sc_seg_ctime = ktime_get_real_seconds();
2116
2117		err = nilfs_segctor_collect(sci, nilfs, mode);
2118		if (unlikely(err))
2119			goto failed;
2120
2121		/* Avoid empty segment */
2122		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE &&
2123		    nilfs_segbuf_empty(sci->sc_curseg)) {
2124			nilfs_segctor_abort_construction(sci, nilfs, 1);
2125			goto out;
2126		}
2127
2128		err = nilfs_segctor_assign(sci, mode);
2129		if (unlikely(err))
2130			goto failed;
2131
2132		if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
2133			nilfs_segctor_fill_in_file_bmap(sci);
2134
2135		if (mode == SC_LSEG_SR &&
2136		    nilfs_sc_cstage_get(sci) >= NILFS_ST_CPFILE) {
2137			err = nilfs_cpfile_finalize_checkpoint(
2138				nilfs->ns_cpfile, nilfs->ns_cno, sci->sc_root,
2139				sci->sc_nblk_inc + sci->sc_nblk_this_inc,
2140				sci->sc_seg_ctime,
2141				!test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags));
2142			if (unlikely(err))
2143				goto failed_to_write;
2144
2145			nilfs_segctor_fill_in_super_root(sci, nilfs);
2146		}
2147		nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
2148
2149		/* Write partial segments */
2150		nilfs_prepare_write_logs(&sci->sc_segbufs, nilfs->ns_crc_seed);
 
 
 
2151
2152		err = nilfs_segctor_write(sci, nilfs);
2153		if (unlikely(err))
2154			goto failed_to_write;
2155
2156		if (nilfs_sc_cstage_get(sci) == NILFS_ST_DONE ||
2157		    nilfs->ns_blocksize_bits != PAGE_SHIFT) {
2158			/*
2159			 * At this point, we avoid double buffering
2160			 * for blocksize < pagesize because page dirty
2161			 * flag is turned off during write and dirty
2162			 * buffers are not properly collected for
2163			 * pages crossing over segments.
2164			 */
2165			err = nilfs_segctor_wait(sci);
2166			if (err)
2167				goto failed_to_write;
2168		}
2169	} while (nilfs_sc_cstage_get(sci) != NILFS_ST_DONE);
2170
2171 out:
2172	nilfs_segctor_drop_written_files(sci, nilfs);
2173	return err;
2174
2175 failed_to_write:
 
 
 
2176 failed:
2177	if (mode == SC_LSEG_SR && nilfs_sc_cstage_get(sci) >= NILFS_ST_IFILE)
2178		nilfs_redirty_inodes(&sci->sc_dirty_files);
2179	if (nilfs_doing_gc())
2180		nilfs_redirty_inodes(&sci->sc_gc_inodes);
2181	nilfs_segctor_abort_construction(sci, nilfs, err);
2182	goto out;
2183}
2184
2185/**
2186 * nilfs_segctor_start_timer - set timer of background write
2187 * @sci: nilfs_sc_info
2188 *
2189 * If the timer has already been set, it ignores the new request.
2190 * This function MUST be called within a section locking the segment
2191 * semaphore.
2192 */
2193static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2194{
2195	spin_lock(&sci->sc_state_lock);
2196	if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2197		if (sci->sc_task) {
2198			sci->sc_timer.expires = jiffies + sci->sc_interval;
2199			add_timer(&sci->sc_timer);
2200		}
2201		sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2202	}
2203	spin_unlock(&sci->sc_state_lock);
2204}
2205
2206static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2207{
2208	spin_lock(&sci->sc_state_lock);
2209	if (!(sci->sc_flush_request & BIT(bn))) {
2210		unsigned long prev_req = sci->sc_flush_request;
2211
2212		sci->sc_flush_request |= BIT(bn);
2213		if (!prev_req)
2214			wake_up(&sci->sc_wait_daemon);
2215	}
2216	spin_unlock(&sci->sc_state_lock);
2217}
2218
2219/**
2220 * nilfs_flush_segment - trigger a segment construction for resource control
2221 * @sb: super block
2222 * @ino: inode number of the file to be flushed out.
2223 */
2224void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2225{
2226	struct the_nilfs *nilfs = sb->s_fs_info;
2227	struct nilfs_sc_info *sci = nilfs->ns_writer;
2228
2229	if (!sci || nilfs_doing_construction())
2230		return;
2231	nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2232					/* assign bit 0 to data files */
2233}
2234
2235struct nilfs_segctor_wait_request {
2236	wait_queue_entry_t	wq;
2237	__u32		seq;
2238	int		err;
2239	atomic_t	done;
2240};
2241
2242static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2243{
2244	struct nilfs_segctor_wait_request wait_req;
2245	int err = 0;
2246
 
2247	init_wait(&wait_req.wq);
2248	wait_req.err = 0;
2249	atomic_set(&wait_req.done, 0);
2250	init_waitqueue_entry(&wait_req.wq, current);
2251
2252	/*
2253	 * To prevent a race issue where completion notifications from the
2254	 * log writer thread are missed, increment the request sequence count
2255	 * "sc_seq_request" and insert a wait queue entry using the current
2256	 * sequence number into the "sc_wait_request" queue at the same time
2257	 * within the lock section of "sc_state_lock".
2258	 */
2259	spin_lock(&sci->sc_state_lock);
2260	wait_req.seq = ++sci->sc_seq_request;
2261	add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2262	spin_unlock(&sci->sc_state_lock);
2263
 
 
 
2264	wake_up(&sci->sc_wait_daemon);
2265
2266	for (;;) {
2267		set_current_state(TASK_INTERRUPTIBLE);
2268
2269		/*
2270		 * Synchronize only while the log writer thread is alive.
2271		 * Leave flushing out after the log writer thread exits to
2272		 * the cleanup work in nilfs_segctor_destroy().
2273		 */
2274		if (!sci->sc_task)
2275			break;
2276
2277		if (atomic_read(&wait_req.done)) {
2278			err = wait_req.err;
2279			break;
2280		}
2281		if (!signal_pending(current)) {
2282			schedule();
2283			continue;
2284		}
2285		err = -ERESTARTSYS;
2286		break;
2287	}
2288	finish_wait(&sci->sc_wait_request, &wait_req.wq);
2289	return err;
2290}
2291
2292static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err, bool force)
2293{
2294	struct nilfs_segctor_wait_request *wrq, *n;
2295	unsigned long flags;
2296
2297	spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2298	list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.head, wq.entry) {
2299		if (!atomic_read(&wrq->done) &&
2300		    (force || nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq))) {
2301			wrq->err = err;
2302			atomic_set(&wrq->done, 1);
2303		}
2304		if (atomic_read(&wrq->done)) {
2305			wrq->wq.func(&wrq->wq,
2306				     TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2307				     0, NULL);
2308		}
2309	}
2310	spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2311}
2312
2313/**
2314 * nilfs_construct_segment - construct a logical segment
2315 * @sb: super block
2316 *
2317 * Return Value: On success, 0 is returned. On errors, one of the following
2318 * negative error code is returned.
2319 *
2320 * %-EROFS - Read only filesystem.
2321 *
2322 * %-EIO - I/O error
2323 *
2324 * %-ENOSPC - No space left on device (only in a panic state).
2325 *
2326 * %-ERESTARTSYS - Interrupted.
2327 *
2328 * %-ENOMEM - Insufficient memory available.
2329 */
2330int nilfs_construct_segment(struct super_block *sb)
2331{
2332	struct the_nilfs *nilfs = sb->s_fs_info;
2333	struct nilfs_sc_info *sci = nilfs->ns_writer;
2334	struct nilfs_transaction_info *ti;
2335
2336	if (sb_rdonly(sb) || unlikely(!sci))
2337		return -EROFS;
2338
2339	/* A call inside transactions causes a deadlock. */
2340	BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2341
2342	return nilfs_segctor_sync(sci);
2343}
2344
2345/**
2346 * nilfs_construct_dsync_segment - construct a data-only logical segment
2347 * @sb: super block
2348 * @inode: inode whose data blocks should be written out
2349 * @start: start byte offset
2350 * @end: end byte offset (inclusive)
2351 *
2352 * Return Value: On success, 0 is returned. On errors, one of the following
2353 * negative error code is returned.
2354 *
2355 * %-EROFS - Read only filesystem.
2356 *
2357 * %-EIO - I/O error
2358 *
2359 * %-ENOSPC - No space left on device (only in a panic state).
2360 *
2361 * %-ERESTARTSYS - Interrupted.
2362 *
2363 * %-ENOMEM - Insufficient memory available.
2364 */
2365int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2366				  loff_t start, loff_t end)
2367{
2368	struct the_nilfs *nilfs = sb->s_fs_info;
2369	struct nilfs_sc_info *sci = nilfs->ns_writer;
2370	struct nilfs_inode_info *ii;
2371	struct nilfs_transaction_info ti;
2372	int err = 0;
2373
2374	if (sb_rdonly(sb) || unlikely(!sci))
2375		return -EROFS;
2376
2377	nilfs_transaction_lock(sb, &ti, 0);
2378
2379	ii = NILFS_I(inode);
2380	if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) ||
2381	    nilfs_test_opt(nilfs, STRICT_ORDER) ||
2382	    test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2383	    nilfs_discontinued(nilfs)) {
2384		nilfs_transaction_unlock(sb);
2385		err = nilfs_segctor_sync(sci);
2386		return err;
2387	}
2388
2389	spin_lock(&nilfs->ns_inode_lock);
2390	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2391	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2392		spin_unlock(&nilfs->ns_inode_lock);
2393		nilfs_transaction_unlock(sb);
2394		return 0;
2395	}
2396	spin_unlock(&nilfs->ns_inode_lock);
2397	sci->sc_dsync_inode = ii;
2398	sci->sc_dsync_start = start;
2399	sci->sc_dsync_end = end;
2400
2401	err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
2402	if (!err)
2403		nilfs->ns_flushed_device = 0;
2404
2405	nilfs_transaction_unlock(sb);
2406	return err;
2407}
2408
2409#define FLUSH_FILE_BIT	(0x1) /* data file only */
2410#define FLUSH_DAT_BIT	BIT(NILFS_DAT_INO) /* DAT only */
2411
2412/**
2413 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2414 * @sci: segment constructor object
2415 */
2416static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2417{
2418	bool thread_is_alive;
2419
2420	spin_lock(&sci->sc_state_lock);
2421	sci->sc_seq_accepted = sci->sc_seq_request;
2422	thread_is_alive = (bool)sci->sc_task;
2423	spin_unlock(&sci->sc_state_lock);
2424
2425	/*
2426	 * This function does not race with the log writer thread's
2427	 * termination.  Therefore, deleting sc_timer, which should not be
2428	 * done after the log writer thread exits, can be done safely outside
2429	 * the area protected by sc_state_lock.
2430	 */
2431	if (thread_is_alive)
2432		del_timer_sync(&sci->sc_timer);
2433}
2434
2435/**
2436 * nilfs_segctor_notify - notify the result of request to caller threads
2437 * @sci: segment constructor object
2438 * @mode: mode of log forming
2439 * @err: error code to be notified
2440 */
2441static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2442{
2443	/* Clear requests (even when the construction failed) */
2444	spin_lock(&sci->sc_state_lock);
2445
2446	if (mode == SC_LSEG_SR) {
2447		sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2448		sci->sc_seq_done = sci->sc_seq_accepted;
2449		nilfs_segctor_wakeup(sci, err, false);
2450		sci->sc_flush_request = 0;
2451	} else {
2452		if (mode == SC_FLUSH_FILE)
2453			sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2454		else if (mode == SC_FLUSH_DAT)
2455			sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2456
2457		/* re-enable timer if checkpoint creation was not done */
2458		if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && sci->sc_task &&
2459		    time_before(jiffies, sci->sc_timer.expires))
2460			add_timer(&sci->sc_timer);
2461	}
2462	spin_unlock(&sci->sc_state_lock);
2463}
2464
2465/**
2466 * nilfs_segctor_construct - form logs and write them to disk
2467 * @sci: segment constructor object
2468 * @mode: mode of log forming
2469 */
2470static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2471{
2472	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2473	struct nilfs_super_block **sbp;
2474	int err = 0;
2475
2476	nilfs_segctor_accept(sci);
2477
2478	if (nilfs_discontinued(nilfs))
2479		mode = SC_LSEG_SR;
2480	if (!nilfs_segctor_confirm(sci))
2481		err = nilfs_segctor_do_construct(sci, mode);
2482
2483	if (likely(!err)) {
2484		if (mode != SC_FLUSH_DAT)
2485			atomic_set(&nilfs->ns_ndirtyblks, 0);
2486		if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2487		    nilfs_discontinued(nilfs)) {
2488			down_write(&nilfs->ns_sem);
2489			err = -EIO;
2490			sbp = nilfs_prepare_super(sci->sc_super,
2491						  nilfs_sb_will_flip(nilfs));
2492			if (likely(sbp)) {
2493				nilfs_set_log_cursor(sbp[0], nilfs);
2494				err = nilfs_commit_super(sci->sc_super,
2495							 NILFS_SB_COMMIT);
2496			}
2497			up_write(&nilfs->ns_sem);
2498		}
2499	}
2500
2501	nilfs_segctor_notify(sci, mode, err);
2502	return err;
2503}
2504
2505static void nilfs_construction_timeout(struct timer_list *t)
2506{
2507	struct nilfs_sc_info *sci = from_timer(sci, t, sc_timer);
2508
2509	wake_up_process(sci->sc_task);
2510}
2511
2512static void
2513nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2514{
2515	struct nilfs_inode_info *ii, *n;
2516
2517	list_for_each_entry_safe(ii, n, head, i_dirty) {
2518		if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2519			continue;
2520		list_del_init(&ii->i_dirty);
2521		truncate_inode_pages(&ii->vfs_inode.i_data, 0);
2522		nilfs_btnode_cache_clear(ii->i_assoc_inode->i_mapping);
2523		iput(&ii->vfs_inode);
2524	}
2525}
2526
2527int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2528			 void **kbufs)
2529{
2530	struct the_nilfs *nilfs = sb->s_fs_info;
2531	struct nilfs_sc_info *sci = nilfs->ns_writer;
2532	struct nilfs_transaction_info ti;
2533	int err;
2534
2535	if (unlikely(!sci))
2536		return -EROFS;
2537
2538	nilfs_transaction_lock(sb, &ti, 1);
2539
2540	err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2541	if (unlikely(err))
2542		goto out_unlock;
2543
2544	err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2545	if (unlikely(err)) {
2546		nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2547		goto out_unlock;
2548	}
2549
2550	sci->sc_freesegs = kbufs[4];
2551	sci->sc_nfreesegs = argv[4].v_nmembs;
2552	list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2553
2554	for (;;) {
2555		err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2556		nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2557
2558		if (likely(!err))
2559			break;
2560
2561		nilfs_warn(sb, "error %d cleaning segments", err);
2562		set_current_state(TASK_INTERRUPTIBLE);
2563		schedule_timeout(sci->sc_interval);
2564	}
2565	if (nilfs_test_opt(nilfs, DISCARD)) {
2566		int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2567						 sci->sc_nfreesegs);
2568		if (ret) {
2569			nilfs_warn(sb,
2570				   "error %d on discard request, turning discards off for the device",
2571				   ret);
2572			nilfs_clear_opt(nilfs, DISCARD);
2573		}
2574	}
2575
2576 out_unlock:
2577	sci->sc_freesegs = NULL;
2578	sci->sc_nfreesegs = 0;
2579	nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2580	nilfs_transaction_unlock(sb);
2581	return err;
2582}
2583
2584static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2585{
2586	struct nilfs_transaction_info ti;
2587
2588	nilfs_transaction_lock(sci->sc_super, &ti, 0);
2589	nilfs_segctor_construct(sci, mode);
2590
2591	/*
2592	 * Unclosed segment should be retried.  We do this using sc_timer.
2593	 * Timeout of sc_timer will invoke complete construction which leads
2594	 * to close the current logical segment.
2595	 */
2596	if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2597		nilfs_segctor_start_timer(sci);
2598
2599	nilfs_transaction_unlock(sci->sc_super);
2600}
2601
2602static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2603{
2604	int mode = 0;
2605
2606	spin_lock(&sci->sc_state_lock);
2607	mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2608		SC_FLUSH_DAT : SC_FLUSH_FILE;
2609	spin_unlock(&sci->sc_state_lock);
2610
2611	if (mode) {
2612		nilfs_segctor_do_construct(sci, mode);
2613
2614		spin_lock(&sci->sc_state_lock);
2615		sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2616			~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2617		spin_unlock(&sci->sc_state_lock);
2618	}
2619	clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2620}
2621
2622static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2623{
2624	if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2625	    time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2626		if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2627			return SC_FLUSH_FILE;
2628		else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2629			return SC_FLUSH_DAT;
2630	}
2631	return SC_LSEG_SR;
2632}
2633
2634/**
2635 * nilfs_log_write_required - determine whether log writing is required
2636 * @sci:   nilfs_sc_info struct
2637 * @modep: location for storing log writing mode
2638 *
2639 * Return: true if log writing is required, false otherwise.  If log writing
2640 * is required, the mode is stored in the location pointed to by @modep.
2641 */
2642static bool nilfs_log_write_required(struct nilfs_sc_info *sci, int *modep)
2643{
2644	bool timedout, ret = true;
2645
2646	spin_lock(&sci->sc_state_lock);
2647	timedout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2648		   time_after_eq(jiffies, sci->sc_timer.expires));
2649	if (timedout || sci->sc_seq_request != sci->sc_seq_done)
2650		*modep = SC_LSEG_SR;
2651	else if (sci->sc_flush_request)
2652		*modep = nilfs_segctor_flush_mode(sci);
2653	else
2654		ret = false;
2655
2656	spin_unlock(&sci->sc_state_lock);
2657	return ret;
2658}
2659
2660/**
2661 * nilfs_segctor_thread - main loop of the log writer thread
2662 * @arg: pointer to a struct nilfs_sc_info.
2663 *
2664 * nilfs_segctor_thread() is the main loop function of the log writer kernel
2665 * thread, which determines whether log writing is necessary, and if so,
2666 * performs the log write in the background, or waits if not.  It is also
2667 * used to decide the background writeback of the superblock.
2668 *
2669 * Return: Always 0.
2670 */
2671static int nilfs_segctor_thread(void *arg)
2672{
2673	struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2674	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 
 
 
2675
 
 
 
2676	nilfs_info(sci->sc_super,
2677		   "segctord starting. Construction interval = %lu seconds, CP frequency < %lu seconds",
2678		   sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2679
2680	set_freezable();
 
 
 
 
2681
2682	while (!kthread_should_stop()) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2683		DEFINE_WAIT(wait);
2684		bool should_write;
2685		int mode;
2686
2687		if (freezing(current)) {
2688			try_to_freeze();
2689			continue;
2690		}
2691
2692		prepare_to_wait(&sci->sc_wait_daemon, &wait,
2693				TASK_INTERRUPTIBLE);
2694		should_write = nilfs_log_write_required(sci, &mode);
2695		if (!should_write)
 
 
 
 
 
 
 
 
 
2696			schedule();
 
 
2697		finish_wait(&sci->sc_wait_daemon, &wait);
 
 
2698
2699		if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2700			set_nilfs_discontinued(nilfs);
2701
2702		if (should_write)
2703			nilfs_segctor_thread_construct(sci, mode);
2704	}
 
2705
 
2706	/* end sync. */
2707	spin_lock(&sci->sc_state_lock);
2708	sci->sc_task = NULL;
2709	timer_shutdown_sync(&sci->sc_timer);
2710	spin_unlock(&sci->sc_state_lock);
2711	return 0;
2712}
2713
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2714/*
2715 * Setup & clean-up functions
2716 */
2717static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2718					       struct nilfs_root *root)
2719{
2720	struct the_nilfs *nilfs = sb->s_fs_info;
2721	struct nilfs_sc_info *sci;
2722
2723	sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2724	if (!sci)
2725		return NULL;
2726
2727	sci->sc_super = sb;
2728
2729	nilfs_get_root(root);
2730	sci->sc_root = root;
2731
2732	init_waitqueue_head(&sci->sc_wait_request);
2733	init_waitqueue_head(&sci->sc_wait_daemon);
 
2734	spin_lock_init(&sci->sc_state_lock);
2735	INIT_LIST_HEAD(&sci->sc_dirty_files);
2736	INIT_LIST_HEAD(&sci->sc_segbufs);
2737	INIT_LIST_HEAD(&sci->sc_write_logs);
2738	INIT_LIST_HEAD(&sci->sc_gc_inodes);
2739	INIT_LIST_HEAD(&sci->sc_iput_queue);
2740	INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func);
 
2741
2742	sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2743	sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2744	sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2745
2746	if (nilfs->ns_interval)
2747		sci->sc_interval = HZ * nilfs->ns_interval;
2748	if (nilfs->ns_watermark)
2749		sci->sc_watermark = nilfs->ns_watermark;
2750	return sci;
2751}
2752
2753static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2754{
2755	int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2756
2757	/*
2758	 * The segctord thread was stopped and its timer was removed.
2759	 * But some tasks remain.
2760	 */
2761	do {
2762		struct nilfs_transaction_info ti;
2763
2764		nilfs_transaction_lock(sci->sc_super, &ti, 0);
2765		ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2766		nilfs_transaction_unlock(sci->sc_super);
2767
2768		flush_work(&sci->sc_iput_work);
2769
2770	} while (ret && ret != -EROFS && retrycount-- > 0);
2771}
2772
2773/**
2774 * nilfs_segctor_destroy - destroy the segment constructor.
2775 * @sci: nilfs_sc_info
2776 *
2777 * nilfs_segctor_destroy() kills the segctord thread and frees
2778 * the nilfs_sc_info struct.
2779 * Caller must hold the segment semaphore.
2780 */
2781static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2782{
2783	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2784	int flag;
2785
2786	up_write(&nilfs->ns_segctor_sem);
2787
2788	if (sci->sc_task) {
2789		wake_up(&sci->sc_wait_daemon);
2790		kthread_stop(sci->sc_task);
2791	}
2792
2793	spin_lock(&sci->sc_state_lock);
 
2794	flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2795		|| sci->sc_seq_request != sci->sc_seq_done);
2796	spin_unlock(&sci->sc_state_lock);
2797
2798	/*
2799	 * Forcibly wake up tasks waiting in nilfs_segctor_sync(), which can
2800	 * be called from delayed iput() via nilfs_evict_inode() and can race
2801	 * with the above log writer thread termination.
2802	 */
2803	nilfs_segctor_wakeup(sci, 0, true);
2804
2805	if (flush_work(&sci->sc_iput_work))
2806		flag = true;
2807
2808	if (flag || !nilfs_segctor_confirm(sci))
2809		nilfs_segctor_write_out(sci);
2810
2811	if (!list_empty(&sci->sc_dirty_files)) {
2812		nilfs_warn(sci->sc_super,
2813			   "disposed unprocessed dirty file(s) when stopping log writer");
2814		nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2815	}
2816
2817	if (!list_empty(&sci->sc_iput_queue)) {
2818		nilfs_warn(sci->sc_super,
2819			   "disposed unprocessed inode(s) in iput queue when stopping log writer");
2820		nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1);
2821	}
2822
2823	WARN_ON(!list_empty(&sci->sc_segbufs));
2824	WARN_ON(!list_empty(&sci->sc_write_logs));
2825
2826	nilfs_put_root(sci->sc_root);
2827
2828	down_write(&nilfs->ns_segctor_sem);
2829
 
2830	kfree(sci);
2831}
2832
2833/**
2834 * nilfs_attach_log_writer - attach log writer
2835 * @sb: super block instance
2836 * @root: root object of the current filesystem tree
2837 *
2838 * This allocates a log writer object, initializes it, and starts the
2839 * log writer.
2840 *
2841 * Return: 0 on success, or the following negative error code on failure.
2842 * * %-EINTR	- Log writer thread creation failed due to interruption.
2843 * * %-ENOMEM	- Insufficient memory available.
 
2844 */
2845int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2846{
2847	struct the_nilfs *nilfs = sb->s_fs_info;
2848	struct nilfs_sc_info *sci;
2849	struct task_struct *t;
2850	int err;
2851
2852	if (nilfs->ns_writer) {
2853		/*
2854		 * This happens if the filesystem is made read-only by
2855		 * __nilfs_error or nilfs_remount and then remounted
2856		 * read/write.  In these cases, reuse the existing
2857		 * writer.
2858		 */
2859		return 0;
2860	}
2861
2862	sci = nilfs_segctor_new(sb, root);
2863	if (unlikely(!sci))
2864		return -ENOMEM;
2865
2866	nilfs->ns_writer = sci;
2867	t = kthread_create(nilfs_segctor_thread, sci, "segctord");
2868	if (IS_ERR(t)) {
2869		err = PTR_ERR(t);
2870		nilfs_err(sb, "error %d creating segctord thread", err);
2871		nilfs_detach_log_writer(sb);
2872		return err;
2873	}
2874	sci->sc_task = t;
2875	timer_setup(&sci->sc_timer, nilfs_construction_timeout, 0);
2876
2877	wake_up_process(sci->sc_task);
2878	return 0;
2879}
2880
2881/**
2882 * nilfs_detach_log_writer - destroy log writer
2883 * @sb: super block instance
2884 *
2885 * This kills log writer daemon, frees the log writer object, and
2886 * destroys list of dirty files.
2887 */
2888void nilfs_detach_log_writer(struct super_block *sb)
2889{
2890	struct the_nilfs *nilfs = sb->s_fs_info;
2891	LIST_HEAD(garbage_list);
2892
2893	down_write(&nilfs->ns_segctor_sem);
2894	if (nilfs->ns_writer) {
2895		nilfs_segctor_destroy(nilfs->ns_writer);
2896		nilfs->ns_writer = NULL;
2897	}
2898	set_nilfs_purging(nilfs);
2899
2900	/* Force to free the list of dirty files */
2901	spin_lock(&nilfs->ns_inode_lock);
2902	if (!list_empty(&nilfs->ns_dirty_files)) {
2903		list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2904		nilfs_warn(sb,
2905			   "disposed unprocessed dirty file(s) when detaching log writer");
2906	}
2907	spin_unlock(&nilfs->ns_inode_lock);
2908	up_write(&nilfs->ns_segctor_sem);
2909
2910	nilfs_dispose_list(nilfs, &garbage_list, 1);
2911	clear_nilfs_purging(nilfs);
2912}