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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}
v3.1
 
   1/*
   2 * segment.c - NILFS segment constructor.
   3 *
   4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 *
  20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
  21 *
  22 */
  23
  24#include <linux/pagemap.h>
  25#include <linux/buffer_head.h>
  26#include <linux/writeback.h>
 
  27#include <linux/bio.h>
  28#include <linux/completion.h>
  29#include <linux/blkdev.h>
  30#include <linux/backing-dev.h>
  31#include <linux/freezer.h>
  32#include <linux/kthread.h>
  33#include <linux/crc32.h>
  34#include <linux/pagevec.h>
  35#include <linux/slab.h>
 
 
  36#include "nilfs.h"
  37#include "btnode.h"
  38#include "page.h"
  39#include "segment.h"
  40#include "sufile.h"
  41#include "cpfile.h"
  42#include "ifile.h"
  43#include "segbuf.h"
  44
  45
  46/*
  47 * Segment constructor
  48 */
  49#define SC_N_INODEVEC	16   /* Size of locally allocated inode vector */
  50
  51#define SC_MAX_SEGDELTA 64   /* Upper limit of the number of segments
  52				appended in collection retry loop */
 
 
  53
  54/* Construction mode */
  55enum {
  56	SC_LSEG_SR = 1,	/* Make a logical segment having a super root */
  57	SC_LSEG_DSYNC,	/* Flush data blocks of a given file and make
  58			   a logical segment without a super root */
  59	SC_FLUSH_FILE,	/* Flush data files, leads to segment writes without
  60			   creating a checkpoint */
  61	SC_FLUSH_DAT,	/* Flush DAT file. This also creates segments without
  62			   a checkpoint */
 
 
 
 
 
 
  63};
  64
  65/* Stage numbers of dirty block collection */
  66enum {
  67	NILFS_ST_INIT = 0,
  68	NILFS_ST_GC,		/* Collecting dirty blocks for GC */
  69	NILFS_ST_FILE,
  70	NILFS_ST_IFILE,
  71	NILFS_ST_CPFILE,
  72	NILFS_ST_SUFILE,
  73	NILFS_ST_DAT,
  74	NILFS_ST_SR,		/* Super root */
  75	NILFS_ST_DSYNC,		/* Data sync blocks */
  76	NILFS_ST_DONE,
  77};
  78
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  79/* State flags of collection */
  80#define NILFS_CF_NODE		0x0001	/* Collecting node blocks */
  81#define NILFS_CF_IFILE_STARTED	0x0002	/* IFILE stage has started */
  82#define NILFS_CF_SUFREED	0x0004	/* segment usages has been freed */
  83#define NILFS_CF_HISTORY_MASK	(NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED)
  84
  85/* Operations depending on the construction mode and file type */
  86struct nilfs_sc_operations {
  87	int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *,
  88			    struct inode *);
  89	int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *,
  90			    struct inode *);
  91	int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *,
  92			    struct inode *);
  93	void (*write_data_binfo)(struct nilfs_sc_info *,
  94				 struct nilfs_segsum_pointer *,
  95				 union nilfs_binfo *);
  96	void (*write_node_binfo)(struct nilfs_sc_info *,
  97				 struct nilfs_segsum_pointer *,
  98				 union nilfs_binfo *);
  99};
 100
 101/*
 102 * Other definitions
 103 */
 104static void nilfs_segctor_start_timer(struct nilfs_sc_info *);
 105static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int);
 106static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *);
 107static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int);
 108
 109#define nilfs_cnt32_gt(a, b)   \
 110	(typecheck(__u32, a) && typecheck(__u32, b) && \
 111	 ((__s32)(b) - (__s32)(a) < 0))
 112#define nilfs_cnt32_ge(a, b)   \
 113	(typecheck(__u32, a) && typecheck(__u32, b) && \
 114	 ((__s32)(a) - (__s32)(b) >= 0))
 115#define nilfs_cnt32_lt(a, b)  nilfs_cnt32_gt(b, a)
 116#define nilfs_cnt32_le(a, b)  nilfs_cnt32_ge(b, a)
 117
 118static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
 
 119{
 120	struct nilfs_transaction_info *cur_ti = current->journal_info;
 121	void *save = NULL;
 122
 123	if (cur_ti) {
 124		if (cur_ti->ti_magic == NILFS_TI_MAGIC)
 125			return ++cur_ti->ti_count;
 126		else {
 127			/*
 128			 * If journal_info field is occupied by other FS,
 129			 * it is saved and will be restored on
 130			 * nilfs_transaction_commit().
 131			 */
 132			printk(KERN_WARNING
 133			       "NILFS warning: journal info from a different "
 134			       "FS\n");
 135			save = current->journal_info;
 136		}
 137	}
 138	if (!ti) {
 139		ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS);
 140		if (!ti)
 141			return -ENOMEM;
 142		ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC;
 143	} else {
 144		ti->ti_flags = 0;
 145	}
 146	ti->ti_count = 0;
 147	ti->ti_save = save;
 148	ti->ti_magic = NILFS_TI_MAGIC;
 149	current->journal_info = ti;
 150	return 0;
 151}
 152
 153/**
 154 * nilfs_transaction_begin - start indivisible file operations.
 155 * @sb: super block
 156 * @ti: nilfs_transaction_info
 157 * @vacancy_check: flags for vacancy rate checks
 158 *
 159 * nilfs_transaction_begin() acquires a reader/writer semaphore, called
 160 * the segment semaphore, to make a segment construction and write tasks
 161 * exclusive.  The function is used with nilfs_transaction_commit() in pairs.
 162 * The region enclosed by these two functions can be nested.  To avoid a
 163 * deadlock, the semaphore is only acquired or released in the outermost call.
 164 *
 165 * This function allocates a nilfs_transaction_info struct to keep context
 166 * information on it.  It is initialized and hooked onto the current task in
 167 * the outermost call.  If a pre-allocated struct is given to @ti, it is used
 168 * instead; otherwise a new struct is assigned from a slab.
 169 *
 170 * When @vacancy_check flag is set, this function will check the amount of
 171 * free space, and will wait for the GC to reclaim disk space if low capacity.
 172 *
 173 * Return Value: On success, 0 is returned. On error, one of the following
 174 * negative error code is returned.
 175 *
 176 * %-ENOMEM - Insufficient memory available.
 177 *
 178 * %-ENOSPC - No space left on device
 179 */
 180int nilfs_transaction_begin(struct super_block *sb,
 181			    struct nilfs_transaction_info *ti,
 182			    int vacancy_check)
 183{
 184	struct the_nilfs *nilfs;
 185	int ret = nilfs_prepare_segment_lock(ti);
 
 186
 187	if (unlikely(ret < 0))
 188		return ret;
 189	if (ret > 0)
 
 
 
 
 
 190		return 0;
 
 191
 192	vfs_check_frozen(sb, SB_FREEZE_WRITE);
 193
 194	nilfs = sb->s_fs_info;
 195	down_read(&nilfs->ns_segctor_sem);
 196	if (vacancy_check && nilfs_near_disk_full(nilfs)) {
 197		up_read(&nilfs->ns_segctor_sem);
 198		ret = -ENOSPC;
 199		goto failed;
 200	}
 
 
 
 
 
 201	return 0;
 202
 203 failed:
 204	ti = current->journal_info;
 205	current->journal_info = ti->ti_save;
 206	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 207		kmem_cache_free(nilfs_transaction_cachep, ti);
 
 208	return ret;
 209}
 210
 211/**
 212 * nilfs_transaction_commit - commit indivisible file operations.
 213 * @sb: super block
 214 *
 215 * nilfs_transaction_commit() releases the read semaphore which is
 216 * acquired by nilfs_transaction_begin(). This is only performed
 217 * in outermost call of this function.  If a commit flag is set,
 218 * nilfs_transaction_commit() sets a timer to start the segment
 219 * constructor.  If a sync flag is set, it starts construction
 220 * directly.
 221 */
 222int nilfs_transaction_commit(struct super_block *sb)
 223{
 224	struct nilfs_transaction_info *ti = current->journal_info;
 225	struct the_nilfs *nilfs = sb->s_fs_info;
 226	int err = 0;
 227
 228	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 229	ti->ti_flags |= NILFS_TI_COMMIT;
 230	if (ti->ti_count > 0) {
 231		ti->ti_count--;
 
 
 232		return 0;
 233	}
 234	if (nilfs->ns_writer) {
 235		struct nilfs_sc_info *sci = nilfs->ns_writer;
 236
 237		if (ti->ti_flags & NILFS_TI_COMMIT)
 238			nilfs_segctor_start_timer(sci);
 239		if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark)
 240			nilfs_segctor_do_flush(sci, 0);
 241	}
 242	up_read(&nilfs->ns_segctor_sem);
 
 
 
 243	current->journal_info = ti->ti_save;
 244
 245	if (ti->ti_flags & NILFS_TI_SYNC)
 246		err = nilfs_construct_segment(sb);
 247	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 248		kmem_cache_free(nilfs_transaction_cachep, ti);
 
 249	return err;
 250}
 251
 252void nilfs_transaction_abort(struct super_block *sb)
 253{
 254	struct nilfs_transaction_info *ti = current->journal_info;
 255	struct the_nilfs *nilfs = sb->s_fs_info;
 256
 257	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 258	if (ti->ti_count > 0) {
 259		ti->ti_count--;
 
 
 260		return;
 261	}
 262	up_read(&nilfs->ns_segctor_sem);
 263
 
 
 
 264	current->journal_info = ti->ti_save;
 265	if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
 266		kmem_cache_free(nilfs_transaction_cachep, ti);
 
 267}
 268
 269void nilfs_relax_pressure_in_lock(struct super_block *sb)
 270{
 271	struct the_nilfs *nilfs = sb->s_fs_info;
 272	struct nilfs_sc_info *sci = nilfs->ns_writer;
 273
 274	if (!sci || !sci->sc_flush_request)
 275		return;
 276
 277	set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
 278	up_read(&nilfs->ns_segctor_sem);
 279
 280	down_write(&nilfs->ns_segctor_sem);
 281	if (sci->sc_flush_request &&
 282	    test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) {
 283		struct nilfs_transaction_info *ti = current->journal_info;
 284
 285		ti->ti_flags |= NILFS_TI_WRITER;
 286		nilfs_segctor_do_immediate_flush(sci);
 287		ti->ti_flags &= ~NILFS_TI_WRITER;
 288	}
 289	downgrade_write(&nilfs->ns_segctor_sem);
 290}
 291
 292static void nilfs_transaction_lock(struct super_block *sb,
 293				   struct nilfs_transaction_info *ti,
 294				   int gcflag)
 295{
 296	struct nilfs_transaction_info *cur_ti = current->journal_info;
 297	struct the_nilfs *nilfs = sb->s_fs_info;
 298	struct nilfs_sc_info *sci = nilfs->ns_writer;
 299
 300	WARN_ON(cur_ti);
 301	ti->ti_flags = NILFS_TI_WRITER;
 302	ti->ti_count = 0;
 303	ti->ti_save = cur_ti;
 304	ti->ti_magic = NILFS_TI_MAGIC;
 305	INIT_LIST_HEAD(&ti->ti_garbage);
 306	current->journal_info = ti;
 307
 308	for (;;) {
 
 
 
 309		down_write(&nilfs->ns_segctor_sem);
 310		if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags))
 311			break;
 312
 313		nilfs_segctor_do_immediate_flush(sci);
 314
 315		up_write(&nilfs->ns_segctor_sem);
 316		yield();
 317	}
 318	if (gcflag)
 319		ti->ti_flags |= NILFS_TI_GC;
 
 
 
 320}
 321
 322static void nilfs_transaction_unlock(struct super_block *sb)
 323{
 324	struct nilfs_transaction_info *ti = current->journal_info;
 325	struct the_nilfs *nilfs = sb->s_fs_info;
 326
 327	BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
 328	BUG_ON(ti->ti_count > 0);
 329
 330	up_write(&nilfs->ns_segctor_sem);
 331	current->journal_info = ti->ti_save;
 332	if (!list_empty(&ti->ti_garbage))
 333		nilfs_dispose_list(nilfs, &ti->ti_garbage, 0);
 
 334}
 335
 336static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci,
 337					    struct nilfs_segsum_pointer *ssp,
 338					    unsigned bytes)
 339{
 340	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 341	unsigned blocksize = sci->sc_super->s_blocksize;
 342	void *p;
 343
 344	if (unlikely(ssp->offset + bytes > blocksize)) {
 345		ssp->offset = 0;
 346		BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh,
 347					       &segbuf->sb_segsum_buffers));
 348		ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh);
 349	}
 350	p = ssp->bh->b_data + ssp->offset;
 351	ssp->offset += bytes;
 352	return p;
 353}
 354
 355/**
 356 * nilfs_segctor_reset_segment_buffer - reset the current segment buffer
 357 * @sci: nilfs_sc_info
 358 */
 359static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci)
 360{
 361	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 362	struct buffer_head *sumbh;
 363	unsigned sumbytes;
 364	unsigned flags = 0;
 365	int err;
 366
 367	if (nilfs_doing_gc())
 368		flags = NILFS_SS_GC;
 369	err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno);
 370	if (unlikely(err))
 371		return err;
 372
 373	sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
 374	sumbytes = segbuf->sb_sum.sumbytes;
 375	sci->sc_finfo_ptr.bh = sumbh;  sci->sc_finfo_ptr.offset = sumbytes;
 376	sci->sc_binfo_ptr.bh = sumbh;  sci->sc_binfo_ptr.offset = sumbytes;
 377	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 378	return 0;
 379}
 380
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 381static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci)
 382{
 383	sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
 384	if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs))
 385		return -E2BIG; /* The current segment is filled up
 386				  (internal code) */
 
 
 
 387	sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg);
 388	return nilfs_segctor_reset_segment_buffer(sci);
 389}
 390
 391static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci)
 392{
 393	struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
 394	int err;
 395
 396	if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) {
 397		err = nilfs_segctor_feed_segment(sci);
 398		if (err)
 399			return err;
 400		segbuf = sci->sc_curseg;
 401	}
 402	err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root);
 403	if (likely(!err))
 404		segbuf->sb_sum.flags |= NILFS_SS_SR;
 405	return err;
 406}
 407
 408/*
 409 * Functions for making segment summary and payloads
 410 */
 411static int nilfs_segctor_segsum_block_required(
 412	struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp,
 413	unsigned binfo_size)
 414{
 415	unsigned blocksize = sci->sc_super->s_blocksize;
 416	/* Size of finfo and binfo is enough small against blocksize */
 417
 418	return ssp->offset + binfo_size +
 419		(!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) >
 420		blocksize;
 421}
 422
 423static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci,
 424				      struct inode *inode)
 425{
 426	sci->sc_curseg->sb_sum.nfinfo++;
 427	sci->sc_binfo_ptr = sci->sc_finfo_ptr;
 428	nilfs_segctor_map_segsum_entry(
 429		sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo));
 430
 431	if (NILFS_I(inode)->i_root &&
 432	    !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
 433		set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
 434	/* skip finfo */
 435}
 436
 437static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci,
 438				    struct inode *inode)
 439{
 440	struct nilfs_finfo *finfo;
 441	struct nilfs_inode_info *ii;
 442	struct nilfs_segment_buffer *segbuf;
 443	__u64 cno;
 444
 445	if (sci->sc_blk_cnt == 0)
 446		return;
 447
 448	ii = NILFS_I(inode);
 449
 450	if (test_bit(NILFS_I_GCINODE, &ii->i_state))
 451		cno = ii->i_cno;
 452	else if (NILFS_ROOT_METADATA_FILE(inode->i_ino))
 453		cno = 0;
 454	else
 455		cno = sci->sc_cno;
 456
 457	finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr,
 458						 sizeof(*finfo));
 459	finfo->fi_ino = cpu_to_le64(inode->i_ino);
 460	finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt);
 461	finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt);
 462	finfo->fi_cno = cpu_to_le64(cno);
 463
 464	segbuf = sci->sc_curseg;
 465	segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset +
 466		sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1);
 467	sci->sc_finfo_ptr = sci->sc_binfo_ptr;
 468	sci->sc_blk_cnt = sci->sc_datablk_cnt = 0;
 469}
 470
 471static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci,
 472					struct buffer_head *bh,
 473					struct inode *inode,
 474					unsigned binfo_size)
 475{
 476	struct nilfs_segment_buffer *segbuf;
 477	int required, err = 0;
 478
 479 retry:
 480	segbuf = sci->sc_curseg;
 481	required = nilfs_segctor_segsum_block_required(
 482		sci, &sci->sc_binfo_ptr, binfo_size);
 483	if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) {
 484		nilfs_segctor_end_finfo(sci, inode);
 485		err = nilfs_segctor_feed_segment(sci);
 486		if (err)
 487			return err;
 488		goto retry;
 489	}
 490	if (unlikely(required)) {
 
 491		err = nilfs_segbuf_extend_segsum(segbuf);
 492		if (unlikely(err))
 493			goto failed;
 494	}
 495	if (sci->sc_blk_cnt == 0)
 496		nilfs_segctor_begin_finfo(sci, inode);
 497
 498	nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size);
 499	/* Substitution to vblocknr is delayed until update_blocknr() */
 500	nilfs_segbuf_add_file_buffer(segbuf, bh);
 501	sci->sc_blk_cnt++;
 502 failed:
 503	return err;
 504}
 505
 506/*
 507 * Callback functions that enumerate, mark, and collect dirty blocks
 508 */
 509static int nilfs_collect_file_data(struct nilfs_sc_info *sci,
 510				   struct buffer_head *bh, struct inode *inode)
 511{
 512	int err;
 513
 514	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 515	if (err < 0)
 516		return err;
 517
 518	err = nilfs_segctor_add_file_block(sci, bh, inode,
 519					   sizeof(struct nilfs_binfo_v));
 520	if (!err)
 521		sci->sc_datablk_cnt++;
 522	return err;
 523}
 524
 525static int nilfs_collect_file_node(struct nilfs_sc_info *sci,
 526				   struct buffer_head *bh,
 527				   struct inode *inode)
 528{
 529	return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 530}
 531
 532static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
 533				   struct buffer_head *bh,
 534				   struct inode *inode)
 535{
 536	WARN_ON(!buffer_dirty(bh));
 537	return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 538}
 539
 540static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci,
 541					struct nilfs_segsum_pointer *ssp,
 542					union nilfs_binfo *binfo)
 543{
 544	struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry(
 545		sci, ssp, sizeof(*binfo_v));
 546	*binfo_v = binfo->bi_v;
 547}
 548
 549static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci,
 550					struct nilfs_segsum_pointer *ssp,
 551					union nilfs_binfo *binfo)
 552{
 553	__le64 *vblocknr = nilfs_segctor_map_segsum_entry(
 554		sci, ssp, sizeof(*vblocknr));
 555	*vblocknr = binfo->bi_v.bi_vblocknr;
 556}
 557
 558static struct nilfs_sc_operations nilfs_sc_file_ops = {
 559	.collect_data = nilfs_collect_file_data,
 560	.collect_node = nilfs_collect_file_node,
 561	.collect_bmap = nilfs_collect_file_bmap,
 562	.write_data_binfo = nilfs_write_file_data_binfo,
 563	.write_node_binfo = nilfs_write_file_node_binfo,
 564};
 565
 566static int nilfs_collect_dat_data(struct nilfs_sc_info *sci,
 567				  struct buffer_head *bh, struct inode *inode)
 568{
 569	int err;
 570
 571	err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
 572	if (err < 0)
 573		return err;
 574
 575	err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64));
 576	if (!err)
 577		sci->sc_datablk_cnt++;
 578	return err;
 579}
 580
 581static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci,
 582				  struct buffer_head *bh, struct inode *inode)
 583{
 584	WARN_ON(!buffer_dirty(bh));
 585	return nilfs_segctor_add_file_block(sci, bh, inode,
 586					    sizeof(struct nilfs_binfo_dat));
 587}
 588
 589static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci,
 590				       struct nilfs_segsum_pointer *ssp,
 591				       union nilfs_binfo *binfo)
 592{
 593	__le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp,
 594							  sizeof(*blkoff));
 595	*blkoff = binfo->bi_dat.bi_blkoff;
 596}
 597
 598static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci,
 599				       struct nilfs_segsum_pointer *ssp,
 600				       union nilfs_binfo *binfo)
 601{
 602	struct nilfs_binfo_dat *binfo_dat =
 603		nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat));
 604	*binfo_dat = binfo->bi_dat;
 605}
 606
 607static struct nilfs_sc_operations nilfs_sc_dat_ops = {
 608	.collect_data = nilfs_collect_dat_data,
 609	.collect_node = nilfs_collect_file_node,
 610	.collect_bmap = nilfs_collect_dat_bmap,
 611	.write_data_binfo = nilfs_write_dat_data_binfo,
 612	.write_node_binfo = nilfs_write_dat_node_binfo,
 613};
 614
 615static struct nilfs_sc_operations nilfs_sc_dsync_ops = {
 616	.collect_data = nilfs_collect_file_data,
 617	.collect_node = NULL,
 618	.collect_bmap = NULL,
 619	.write_data_binfo = nilfs_write_file_data_binfo,
 620	.write_node_binfo = NULL,
 621};
 622
 623static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode,
 624					      struct list_head *listp,
 625					      size_t nlimit,
 626					      loff_t start, loff_t end)
 627{
 628	struct address_space *mapping = inode->i_mapping;
 629	struct pagevec pvec;
 630	pgoff_t index = 0, last = ULONG_MAX;
 631	size_t ndirties = 0;
 632	int i;
 633
 634	if (unlikely(start != 0 || end != LLONG_MAX)) {
 635		/*
 636		 * A valid range is given for sync-ing data pages. The
 637		 * range is rounded to per-page; extra dirty buffers
 638		 * may be included if blocksize < pagesize.
 639		 */
 640		index = start >> PAGE_SHIFT;
 641		last = end >> PAGE_SHIFT;
 642	}
 643	pagevec_init(&pvec, 0);
 644 repeat:
 645	if (unlikely(index > last) ||
 646	    !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
 647				min_t(pgoff_t, last - index,
 648				      PAGEVEC_SIZE - 1) + 1))
 649		return ndirties;
 650
 651	for (i = 0; i < pagevec_count(&pvec); i++) {
 652		struct buffer_head *bh, *head;
 653		struct page *page = pvec.pages[i];
 654
 655		if (unlikely(page->index > last))
 656			break;
 
 
 
 
 
 
 
 
 
 657
 658		lock_page(page);
 659		if (!page_has_buffers(page))
 660			create_empty_buffers(page, 1 << inode->i_blkbits, 0);
 661		unlock_page(page);
 662
 663		bh = head = page_buffers(page);
 664		do {
 665			if (!buffer_dirty(bh))
 666				continue;
 667			get_bh(bh);
 668			list_add_tail(&bh->b_assoc_buffers, listp);
 669			ndirties++;
 670			if (unlikely(ndirties >= nlimit)) {
 671				pagevec_release(&pvec);
 672				cond_resched();
 673				return ndirties;
 674			}
 675		} while (bh = bh->b_this_page, bh != head);
 676	}
 677	pagevec_release(&pvec);
 678	cond_resched();
 679	goto repeat;
 680}
 681
 682static void nilfs_lookup_dirty_node_buffers(struct inode *inode,
 683					    struct list_head *listp)
 684{
 685	struct nilfs_inode_info *ii = NILFS_I(inode);
 686	struct address_space *mapping = &ii->i_btnode_cache;
 687	struct pagevec pvec;
 688	struct buffer_head *bh, *head;
 689	unsigned int i;
 690	pgoff_t index = 0;
 691
 692	pagevec_init(&pvec, 0);
 
 
 693
 694	while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
 695				  PAGEVEC_SIZE)) {
 696		for (i = 0; i < pagevec_count(&pvec); i++) {
 697			bh = head = page_buffers(pvec.pages[i]);
 698			do {
 699				if (buffer_dirty(bh)) {
 
 700					get_bh(bh);
 701					list_add_tail(&bh->b_assoc_buffers,
 702						      listp);
 703				}
 704				bh = bh->b_this_page;
 705			} while (bh != head);
 706		}
 707		pagevec_release(&pvec);
 708		cond_resched();
 709	}
 710}
 711
 712static void nilfs_dispose_list(struct the_nilfs *nilfs,
 713			       struct list_head *head, int force)
 714{
 715	struct nilfs_inode_info *ii, *n;
 716	struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii;
 717	unsigned nv = 0;
 718
 719	while (!list_empty(head)) {
 720		spin_lock(&nilfs->ns_inode_lock);
 721		list_for_each_entry_safe(ii, n, head, i_dirty) {
 722			list_del_init(&ii->i_dirty);
 723			if (force) {
 724				if (unlikely(ii->i_bh)) {
 725					brelse(ii->i_bh);
 726					ii->i_bh = NULL;
 727				}
 728			} else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
 729				set_bit(NILFS_I_QUEUED, &ii->i_state);
 730				list_add_tail(&ii->i_dirty,
 731					      &nilfs->ns_dirty_files);
 732				continue;
 733			}
 734			ivec[nv++] = ii;
 735			if (nv == SC_N_INODEVEC)
 736				break;
 737		}
 738		spin_unlock(&nilfs->ns_inode_lock);
 739
 740		for (pii = ivec; nv > 0; pii++, nv--)
 741			iput(&(*pii)->vfs_inode);
 742	}
 743}
 744
 
 
 
 
 
 
 
 
 
 745static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs,
 746				     struct nilfs_root *root)
 747{
 748	int ret = 0;
 749
 750	if (nilfs_mdt_fetch_dirty(root->ifile))
 751		ret++;
 752	if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile))
 753		ret++;
 754	if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile))
 755		ret++;
 756	if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat))
 757		ret++;
 758	return ret;
 759}
 760
 761static int nilfs_segctor_clean(struct nilfs_sc_info *sci)
 762{
 763	return list_empty(&sci->sc_dirty_files) &&
 764		!test_bit(NILFS_SC_DIRTY, &sci->sc_flags) &&
 765		sci->sc_nfreesegs == 0 &&
 766		(!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
 767}
 768
 769static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
 770{
 771	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 772	int ret = 0;
 773
 774	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
 775		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
 776
 777	spin_lock(&nilfs->ns_inode_lock);
 778	if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci))
 779		ret++;
 780
 781	spin_unlock(&nilfs->ns_inode_lock);
 782	return ret;
 783}
 784
 785static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
 786{
 787	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 788
 789	nilfs_mdt_clear_dirty(sci->sc_root->ifile);
 790	nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
 791	nilfs_mdt_clear_dirty(nilfs->ns_sufile);
 792	nilfs_mdt_clear_dirty(nilfs->ns_dat);
 793}
 794
 795static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
 796{
 797	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 798	struct buffer_head *bh_cp;
 799	struct nilfs_checkpoint *raw_cp;
 800	int err;
 801
 802	/* XXX: this interface will be changed */
 803	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1,
 804					  &raw_cp, &bh_cp);
 805	if (likely(!err)) {
 806		/* The following code is duplicated with cpfile.  But, it is
 807		   needed to collect the checkpoint even if it was not newly
 808		   created */
 
 
 809		mark_buffer_dirty(bh_cp);
 810		nilfs_mdt_mark_dirty(nilfs->ns_cpfile);
 811		nilfs_cpfile_put_checkpoint(
 812			nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
 813	} else
 814		WARN_ON(err == -EINVAL || err == -ENOENT);
 815
 
 
 816	return err;
 817}
 818
 819static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
 820{
 821	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
 822	struct buffer_head *bh_cp;
 823	struct nilfs_checkpoint *raw_cp;
 824	int err;
 825
 826	err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0,
 827					  &raw_cp, &bh_cp);
 828	if (unlikely(err)) {
 829		WARN_ON(err == -EINVAL || err == -ENOENT);
 
 
 
 
 830		goto failed_ibh;
 831	}
 832	raw_cp->cp_snapshot_list.ssl_next = 0;
 833	raw_cp->cp_snapshot_list.ssl_prev = 0;
 834	raw_cp->cp_inodes_count =
 835		cpu_to_le64(atomic_read(&sci->sc_root->inodes_count));
 836	raw_cp->cp_blocks_count =
 837		cpu_to_le64(atomic_read(&sci->sc_root->blocks_count));
 838	raw_cp->cp_nblk_inc =
 839		cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc);
 840	raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime);
 841	raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno);
 842
 843	if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags))
 844		nilfs_checkpoint_clear_minor(raw_cp);
 845	else
 846		nilfs_checkpoint_set_minor(raw_cp);
 847
 848	nilfs_write_inode_common(sci->sc_root->ifile,
 849				 &raw_cp->cp_ifile_inode, 1);
 850	nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp);
 851	return 0;
 852
 853 failed_ibh:
 854	return err;
 855}
 856
 857static void nilfs_fill_in_file_bmap(struct inode *ifile,
 858				    struct nilfs_inode_info *ii)
 859
 860{
 861	struct buffer_head *ibh;
 862	struct nilfs_inode *raw_inode;
 863
 864	if (test_bit(NILFS_I_BMAP, &ii->i_state)) {
 865		ibh = ii->i_bh;
 866		BUG_ON(!ibh);
 867		raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino,
 868						  ibh);
 869		nilfs_bmap_write(ii->i_bmap, raw_inode);
 870		nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh);
 871	}
 872}
 873
 874static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci)
 875{
 876	struct nilfs_inode_info *ii;
 877
 878	list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
 879		nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii);
 880		set_bit(NILFS_I_COLLECTED, &ii->i_state);
 881	}
 882}
 883
 884static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
 885					     struct the_nilfs *nilfs)
 886{
 887	struct buffer_head *bh_sr;
 888	struct nilfs_super_root *raw_sr;
 889	unsigned isz, srsz;
 890
 891	bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root;
 
 
 892	raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
 893	isz = nilfs->ns_inode_size;
 894	srsz = NILFS_SR_BYTES(isz);
 895
 
 896	raw_sr->sr_bytes = cpu_to_le16(srsz);
 897	raw_sr->sr_nongc_ctime
 898		= cpu_to_le64(nilfs_doing_gc() ?
 899			      nilfs->ns_nongc_ctime : sci->sc_seg_ctime);
 900	raw_sr->sr_flags = 0;
 901
 902	nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr +
 903				 NILFS_SR_DAT_OFFSET(isz), 1);
 904	nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr +
 905				 NILFS_SR_CPFILE_OFFSET(isz), 1);
 906	nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr +
 907				 NILFS_SR_SUFILE_OFFSET(isz), 1);
 908	memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz);
 
 
 909}
 910
 911static void nilfs_redirty_inodes(struct list_head *head)
 912{
 913	struct nilfs_inode_info *ii;
 914
 915	list_for_each_entry(ii, head, i_dirty) {
 916		if (test_bit(NILFS_I_COLLECTED, &ii->i_state))
 917			clear_bit(NILFS_I_COLLECTED, &ii->i_state);
 918	}
 919}
 920
 921static void nilfs_drop_collected_inodes(struct list_head *head)
 922{
 923	struct nilfs_inode_info *ii;
 924
 925	list_for_each_entry(ii, head, i_dirty) {
 926		if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state))
 927			continue;
 928
 929		clear_bit(NILFS_I_INODE_DIRTY, &ii->i_state);
 930		set_bit(NILFS_I_UPDATED, &ii->i_state);
 931	}
 932}
 933
 934static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci,
 935				       struct inode *inode,
 936				       struct list_head *listp,
 937				       int (*collect)(struct nilfs_sc_info *,
 938						      struct buffer_head *,
 939						      struct inode *))
 940{
 941	struct buffer_head *bh, *n;
 942	int err = 0;
 943
 944	if (collect) {
 945		list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) {
 946			list_del_init(&bh->b_assoc_buffers);
 947			err = collect(sci, bh, inode);
 948			brelse(bh);
 949			if (unlikely(err))
 950				goto dispose_buffers;
 951		}
 952		return 0;
 953	}
 954
 955 dispose_buffers:
 956	while (!list_empty(listp)) {
 957		bh = list_first_entry(listp, struct buffer_head,
 958				      b_assoc_buffers);
 959		list_del_init(&bh->b_assoc_buffers);
 960		brelse(bh);
 961	}
 962	return err;
 963}
 964
 965static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci)
 966{
 967	/* Remaining number of blocks within segment buffer */
 968	return sci->sc_segbuf_nblocks -
 969		(sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks);
 970}
 971
 972static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci,
 973				   struct inode *inode,
 974				   struct nilfs_sc_operations *sc_ops)
 975{
 976	LIST_HEAD(data_buffers);
 977	LIST_HEAD(node_buffers);
 978	int err;
 979
 980	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
 981		size_t n, rest = nilfs_segctor_buffer_rest(sci);
 982
 983		n = nilfs_lookup_dirty_data_buffers(
 984			inode, &data_buffers, rest + 1, 0, LLONG_MAX);
 985		if (n > rest) {
 986			err = nilfs_segctor_apply_buffers(
 987				sci, inode, &data_buffers,
 988				sc_ops->collect_data);
 989			BUG_ON(!err); /* always receive -E2BIG or true error */
 990			goto break_or_fail;
 991		}
 992	}
 993	nilfs_lookup_dirty_node_buffers(inode, &node_buffers);
 994
 995	if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
 996		err = nilfs_segctor_apply_buffers(
 997			sci, inode, &data_buffers, sc_ops->collect_data);
 998		if (unlikely(err)) {
 999			/* dispose node list */
1000			nilfs_segctor_apply_buffers(
1001				sci, inode, &node_buffers, NULL);
1002			goto break_or_fail;
1003		}
1004		sci->sc_stage.flags |= NILFS_CF_NODE;
1005	}
1006	/* Collect node */
1007	err = nilfs_segctor_apply_buffers(
1008		sci, inode, &node_buffers, sc_ops->collect_node);
1009	if (unlikely(err))
1010		goto break_or_fail;
1011
1012	nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers);
1013	err = nilfs_segctor_apply_buffers(
1014		sci, inode, &node_buffers, sc_ops->collect_bmap);
1015	if (unlikely(err))
1016		goto break_or_fail;
1017
1018	nilfs_segctor_end_finfo(sci, inode);
1019	sci->sc_stage.flags &= ~NILFS_CF_NODE;
1020
1021 break_or_fail:
1022	return err;
1023}
1024
1025static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci,
1026					 struct inode *inode)
1027{
1028	LIST_HEAD(data_buffers);
1029	size_t n, rest = nilfs_segctor_buffer_rest(sci);
1030	int err;
1031
1032	n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1,
1033					    sci->sc_dsync_start,
1034					    sci->sc_dsync_end);
1035
1036	err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
1037					  nilfs_collect_file_data);
1038	if (!err) {
1039		nilfs_segctor_end_finfo(sci, inode);
1040		BUG_ON(n > rest);
1041		/* always receive -E2BIG or true error if n > rest */
1042	}
1043	return err;
1044}
1045
1046static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
1047{
1048	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1049	struct list_head *head;
1050	struct nilfs_inode_info *ii;
1051	size_t ndone;
1052	int err = 0;
1053
1054	switch (sci->sc_stage.scnt) {
1055	case NILFS_ST_INIT:
1056		/* Pre-processes */
1057		sci->sc_stage.flags = 0;
1058
1059		if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) {
1060			sci->sc_nblk_inc = 0;
1061			sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN;
1062			if (mode == SC_LSEG_DSYNC) {
1063				sci->sc_stage.scnt = NILFS_ST_DSYNC;
1064				goto dsync_mode;
1065			}
1066		}
1067
1068		sci->sc_stage.dirty_file_ptr = NULL;
1069		sci->sc_stage.gc_inode_ptr = NULL;
1070		if (mode == SC_FLUSH_DAT) {
1071			sci->sc_stage.scnt = NILFS_ST_DAT;
1072			goto dat_stage;
1073		}
1074		sci->sc_stage.scnt++;  /* Fall through */
 
1075	case NILFS_ST_GC:
1076		if (nilfs_doing_gc()) {
1077			head = &sci->sc_gc_inodes;
1078			ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr,
1079						head, i_dirty);
1080			list_for_each_entry_continue(ii, head, i_dirty) {
1081				err = nilfs_segctor_scan_file(
1082					sci, &ii->vfs_inode,
1083					&nilfs_sc_file_ops);
1084				if (unlikely(err)) {
1085					sci->sc_stage.gc_inode_ptr = list_entry(
1086						ii->i_dirty.prev,
1087						struct nilfs_inode_info,
1088						i_dirty);
1089					goto break_or_fail;
1090				}
1091				set_bit(NILFS_I_COLLECTED, &ii->i_state);
1092			}
1093			sci->sc_stage.gc_inode_ptr = NULL;
1094		}
1095		sci->sc_stage.scnt++;  /* Fall through */
 
1096	case NILFS_ST_FILE:
1097		head = &sci->sc_dirty_files;
1098		ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head,
1099					i_dirty);
1100		list_for_each_entry_continue(ii, head, i_dirty) {
1101			clear_bit(NILFS_I_DIRTY, &ii->i_state);
1102
1103			err = nilfs_segctor_scan_file(sci, &ii->vfs_inode,
1104						      &nilfs_sc_file_ops);
1105			if (unlikely(err)) {
1106				sci->sc_stage.dirty_file_ptr =
1107					list_entry(ii->i_dirty.prev,
1108						   struct nilfs_inode_info,
1109						   i_dirty);
1110				goto break_or_fail;
1111			}
1112			/* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */
1113			/* XXX: required ? */
1114		}
1115		sci->sc_stage.dirty_file_ptr = NULL;
1116		if (mode == SC_FLUSH_FILE) {
1117			sci->sc_stage.scnt = NILFS_ST_DONE;
1118			return 0;
1119		}
1120		sci->sc_stage.scnt++;
1121		sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
1122		/* Fall through */
1123	case NILFS_ST_IFILE:
1124		err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile,
1125					      &nilfs_sc_file_ops);
1126		if (unlikely(err))
1127			break;
1128		sci->sc_stage.scnt++;
1129		/* Creating a checkpoint */
1130		err = nilfs_segctor_create_checkpoint(sci);
1131		if (unlikely(err))
1132			break;
1133		/* Fall through */
1134	case NILFS_ST_CPFILE:
1135		err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile,
1136					      &nilfs_sc_file_ops);
1137		if (unlikely(err))
1138			break;
1139		sci->sc_stage.scnt++;  /* Fall through */
 
1140	case NILFS_ST_SUFILE:
1141		err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs,
1142					 sci->sc_nfreesegs, &ndone);
1143		if (unlikely(err)) {
1144			nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1145						  sci->sc_freesegs, ndone,
1146						  NULL);
1147			break;
1148		}
1149		sci->sc_stage.flags |= NILFS_CF_SUFREED;
1150
1151		err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile,
1152					      &nilfs_sc_file_ops);
1153		if (unlikely(err))
1154			break;
1155		sci->sc_stage.scnt++;  /* Fall through */
 
1156	case NILFS_ST_DAT:
1157 dat_stage:
1158		err = nilfs_segctor_scan_file(sci, nilfs->ns_dat,
1159					      &nilfs_sc_dat_ops);
1160		if (unlikely(err))
1161			break;
1162		if (mode == SC_FLUSH_DAT) {
1163			sci->sc_stage.scnt = NILFS_ST_DONE;
1164			return 0;
1165		}
1166		sci->sc_stage.scnt++;  /* Fall through */
 
1167	case NILFS_ST_SR:
1168		if (mode == SC_LSEG_SR) {
1169			/* Appending a super root */
1170			err = nilfs_segctor_add_super_root(sci);
1171			if (unlikely(err))
1172				break;
1173		}
1174		/* End of a logical segment */
1175		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1176		sci->sc_stage.scnt = NILFS_ST_DONE;
1177		return 0;
1178	case NILFS_ST_DSYNC:
1179 dsync_mode:
1180		sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT;
1181		ii = sci->sc_dsync_inode;
1182		if (!test_bit(NILFS_I_BUSY, &ii->i_state))
1183			break;
1184
1185		err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode);
1186		if (unlikely(err))
1187			break;
1188		sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND;
1189		sci->sc_stage.scnt = NILFS_ST_DONE;
1190		return 0;
1191	case NILFS_ST_DONE:
1192		return 0;
1193	default:
1194		BUG();
1195	}
1196
1197 break_or_fail:
1198	return err;
1199}
1200
1201/**
1202 * nilfs_segctor_begin_construction - setup segment buffer to make a new log
1203 * @sci: nilfs_sc_info
1204 * @nilfs: nilfs object
1205 */
1206static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
1207					    struct the_nilfs *nilfs)
1208{
1209	struct nilfs_segment_buffer *segbuf, *prev;
1210	__u64 nextnum;
1211	int err, alloc = 0;
1212
1213	segbuf = nilfs_segbuf_new(sci->sc_super);
1214	if (unlikely(!segbuf))
1215		return -ENOMEM;
1216
1217	if (list_empty(&sci->sc_write_logs)) {
1218		nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
1219				 nilfs->ns_pseg_offset, nilfs);
1220		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1221			nilfs_shift_to_next_segment(nilfs);
1222			nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
1223		}
1224
1225		segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
1226		nextnum = nilfs->ns_nextnum;
1227
1228		if (nilfs->ns_segnum == nilfs->ns_nextnum)
1229			/* Start from the head of a new full segment */
1230			alloc++;
1231	} else {
1232		/* Continue logs */
1233		prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1234		nilfs_segbuf_map_cont(segbuf, prev);
1235		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq;
1236		nextnum = prev->sb_nextnum;
1237
1238		if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
1239			nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1240			segbuf->sb_sum.seg_seq++;
1241			alloc++;
1242		}
1243	}
1244
1245	err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum);
1246	if (err)
1247		goto failed;
1248
1249	if (alloc) {
1250		err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum);
1251		if (err)
1252			goto failed;
1253	}
1254	nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
1255
1256	BUG_ON(!list_empty(&sci->sc_segbufs));
1257	list_add_tail(&segbuf->sb_list, &sci->sc_segbufs);
1258	sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
1259	return 0;
1260
1261 failed:
1262	nilfs_segbuf_free(segbuf);
1263	return err;
1264}
1265
1266static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci,
1267					 struct the_nilfs *nilfs, int nadd)
1268{
1269	struct nilfs_segment_buffer *segbuf, *prev;
1270	struct inode *sufile = nilfs->ns_sufile;
1271	__u64 nextnextnum;
1272	LIST_HEAD(list);
1273	int err, ret, i;
1274
1275	prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
1276	/*
1277	 * Since the segment specified with nextnum might be allocated during
1278	 * the previous construction, the buffer including its segusage may
1279	 * not be dirty.  The following call ensures that the buffer is dirty
1280	 * and will pin the buffer on memory until the sufile is written.
1281	 */
1282	err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum);
1283	if (unlikely(err))
1284		return err;
1285
1286	for (i = 0; i < nadd; i++) {
1287		/* extend segment info */
1288		err = -ENOMEM;
1289		segbuf = nilfs_segbuf_new(sci->sc_super);
1290		if (unlikely(!segbuf))
1291			goto failed;
1292
1293		/* map this buffer to region of segment on-disk */
1294		nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
1295		sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks;
1296
1297		/* allocate the next next full segment */
1298		err = nilfs_sufile_alloc(sufile, &nextnextnum);
1299		if (unlikely(err))
1300			goto failed_segbuf;
1301
1302		segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1;
1303		nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs);
1304
1305		list_add_tail(&segbuf->sb_list, &list);
1306		prev = segbuf;
1307	}
1308	list_splice_tail(&list, &sci->sc_segbufs);
1309	return 0;
1310
1311 failed_segbuf:
1312	nilfs_segbuf_free(segbuf);
1313 failed:
1314	list_for_each_entry(segbuf, &list, sb_list) {
1315		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1316		WARN_ON(ret); /* never fails */
1317	}
1318	nilfs_destroy_logs(&list);
1319	return err;
1320}
1321
1322static void nilfs_free_incomplete_logs(struct list_head *logs,
1323				       struct the_nilfs *nilfs)
1324{
1325	struct nilfs_segment_buffer *segbuf, *prev;
1326	struct inode *sufile = nilfs->ns_sufile;
1327	int ret;
1328
1329	segbuf = NILFS_FIRST_SEGBUF(logs);
1330	if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
1331		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1332		WARN_ON(ret); /* never fails */
1333	}
1334	if (atomic_read(&segbuf->sb_err)) {
1335		/* Case 1: The first segment failed */
1336		if (segbuf->sb_pseg_start != segbuf->sb_fseg_start)
1337			/* Case 1a:  Partial segment appended into an existing
1338			   segment */
 
 
1339			nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start,
1340						segbuf->sb_fseg_end);
1341		else /* Case 1b:  New full segment */
1342			set_nilfs_discontinued(nilfs);
1343	}
1344
1345	prev = segbuf;
1346	list_for_each_entry_continue(segbuf, logs, sb_list) {
1347		if (prev->sb_nextnum != segbuf->sb_nextnum) {
1348			ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1349			WARN_ON(ret); /* never fails */
1350		}
1351		if (atomic_read(&segbuf->sb_err) &&
1352		    segbuf->sb_segnum != nilfs->ns_nextnum)
1353			/* Case 2: extended segment (!= next) failed */
1354			nilfs_sufile_set_error(sufile, segbuf->sb_segnum);
1355		prev = segbuf;
1356	}
1357}
1358
1359static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
1360					  struct inode *sufile)
1361{
1362	struct nilfs_segment_buffer *segbuf;
1363	unsigned long live_blocks;
1364	int ret;
1365
1366	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1367		live_blocks = segbuf->sb_sum.nblocks +
1368			(segbuf->sb_pseg_start - segbuf->sb_fseg_start);
1369		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1370						     live_blocks,
1371						     sci->sc_seg_ctime);
1372		WARN_ON(ret); /* always succeed because the segusage is dirty */
1373	}
1374}
1375
1376static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile)
1377{
1378	struct nilfs_segment_buffer *segbuf;
1379	int ret;
1380
1381	segbuf = NILFS_FIRST_SEGBUF(logs);
1382	ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1383					     segbuf->sb_pseg_start -
1384					     segbuf->sb_fseg_start, 0);
1385	WARN_ON(ret); /* always succeed because the segusage is dirty */
1386
1387	list_for_each_entry_continue(segbuf, logs, sb_list) {
1388		ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum,
1389						     0, 0);
1390		WARN_ON(ret); /* always succeed */
1391	}
1392}
1393
1394static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci,
1395					    struct nilfs_segment_buffer *last,
1396					    struct inode *sufile)
1397{
1398	struct nilfs_segment_buffer *segbuf = last;
1399	int ret;
1400
1401	list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
1402		sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
1403		ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
1404		WARN_ON(ret);
1405	}
1406	nilfs_truncate_logs(&sci->sc_segbufs, last);
1407}
1408
1409
1410static int nilfs_segctor_collect(struct nilfs_sc_info *sci,
1411				 struct the_nilfs *nilfs, int mode)
1412{
1413	struct nilfs_cstage prev_stage = sci->sc_stage;
1414	int err, nadd = 1;
1415
1416	/* Collection retry loop */
1417	for (;;) {
1418		sci->sc_nblk_this_inc = 0;
1419		sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
1420
1421		err = nilfs_segctor_reset_segment_buffer(sci);
1422		if (unlikely(err))
1423			goto failed;
1424
1425		err = nilfs_segctor_collect_blocks(sci, mode);
1426		sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks;
1427		if (!err)
1428			break;
1429
1430		if (unlikely(err != -E2BIG))
1431			goto failed;
1432
1433		/* The current segment is filled up */
1434		if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE)
 
1435			break;
1436
1437		nilfs_clear_logs(&sci->sc_segbufs);
1438
1439		err = nilfs_segctor_extend_segments(sci, nilfs, nadd);
1440		if (unlikely(err))
1441			return err;
1442
1443		if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1444			err = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1445							sci->sc_freesegs,
1446							sci->sc_nfreesegs,
1447							NULL);
1448			WARN_ON(err); /* do not happen */
 
1449		}
 
 
 
 
 
1450		nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA);
1451		sci->sc_stage = prev_stage;
1452	}
 
1453	nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile);
1454	return 0;
1455
1456 failed:
1457	return err;
1458}
1459
1460static void nilfs_list_replace_buffer(struct buffer_head *old_bh,
1461				      struct buffer_head *new_bh)
1462{
1463	BUG_ON(!list_empty(&new_bh->b_assoc_buffers));
1464
1465	list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers);
1466	/* The caller must release old_bh */
1467}
1468
1469static int
1470nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci,
1471				     struct nilfs_segment_buffer *segbuf,
1472				     int mode)
1473{
1474	struct inode *inode = NULL;
1475	sector_t blocknr;
1476	unsigned long nfinfo = segbuf->sb_sum.nfinfo;
1477	unsigned long nblocks = 0, ndatablk = 0;
1478	struct nilfs_sc_operations *sc_op = NULL;
1479	struct nilfs_segsum_pointer ssp;
1480	struct nilfs_finfo *finfo = NULL;
1481	union nilfs_binfo binfo;
1482	struct buffer_head *bh, *bh_org;
1483	ino_t ino = 0;
1484	int err = 0;
1485
1486	if (!nfinfo)
1487		goto out;
1488
1489	blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk;
1490	ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers);
1491	ssp.offset = sizeof(struct nilfs_segment_summary);
1492
1493	list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
1494		if (bh == segbuf->sb_super_root)
1495			break;
1496		if (!finfo) {
1497			finfo =	nilfs_segctor_map_segsum_entry(
1498				sci, &ssp, sizeof(*finfo));
1499			ino = le64_to_cpu(finfo->fi_ino);
1500			nblocks = le32_to_cpu(finfo->fi_nblocks);
1501			ndatablk = le32_to_cpu(finfo->fi_ndatablk);
1502
1503			inode = bh->b_page->mapping->host;
1504
1505			if (mode == SC_LSEG_DSYNC)
1506				sc_op = &nilfs_sc_dsync_ops;
1507			else if (ino == NILFS_DAT_INO)
1508				sc_op = &nilfs_sc_dat_ops;
1509			else /* file blocks */
1510				sc_op = &nilfs_sc_file_ops;
1511		}
1512		bh_org = bh;
1513		get_bh(bh_org);
1514		err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr,
1515					&binfo);
1516		if (bh != bh_org)
1517			nilfs_list_replace_buffer(bh_org, bh);
1518		brelse(bh_org);
1519		if (unlikely(err))
1520			goto failed_bmap;
1521
1522		if (ndatablk > 0)
1523			sc_op->write_data_binfo(sci, &ssp, &binfo);
1524		else
1525			sc_op->write_node_binfo(sci, &ssp, &binfo);
1526
1527		blocknr++;
1528		if (--nblocks == 0) {
1529			finfo = NULL;
1530			if (--nfinfo == 0)
1531				break;
1532		} else if (ndatablk > 0)
1533			ndatablk--;
1534	}
1535 out:
1536	return 0;
1537
1538 failed_bmap:
1539	return err;
1540}
1541
1542static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode)
1543{
1544	struct nilfs_segment_buffer *segbuf;
1545	int err;
1546
1547	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1548		err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode);
1549		if (unlikely(err))
1550			return err;
1551		nilfs_segbuf_fill_in_segsum(segbuf);
1552	}
1553	return 0;
1554}
1555
1556static void nilfs_begin_page_io(struct page *page)
1557{
1558	if (!page || PageWriteback(page))
1559		/* For split b-tree node pages, this function may be called
1560		   twice.  We ignore the 2nd or later calls by this check. */
 
 
1561		return;
1562
1563	lock_page(page);
1564	clear_page_dirty_for_io(page);
1565	set_page_writeback(page);
1566	unlock_page(page);
1567}
1568
1569static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci)
1570{
1571	struct nilfs_segment_buffer *segbuf;
1572	struct page *bd_page = NULL, *fs_page = NULL;
1573
1574	list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
1575		struct buffer_head *bh;
1576
1577		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1578				    b_assoc_buffers) {
1579			if (bh->b_page != bd_page) {
1580				if (bd_page) {
1581					lock_page(bd_page);
1582					clear_page_dirty_for_io(bd_page);
1583					set_page_writeback(bd_page);
1584					unlock_page(bd_page);
1585				}
1586				bd_page = bh->b_page;
1587			}
1588		}
1589
1590		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1591				    b_assoc_buffers) {
1592			if (bh == segbuf->sb_super_root) {
1593				if (bh->b_page != bd_page) {
1594					lock_page(bd_page);
1595					clear_page_dirty_for_io(bd_page);
1596					set_page_writeback(bd_page);
1597					unlock_page(bd_page);
1598					bd_page = bh->b_page;
1599				}
1600				break;
1601			}
1602			if (bh->b_page != fs_page) {
1603				nilfs_begin_page_io(fs_page);
1604				fs_page = bh->b_page;
 
1605			}
1606		}
1607	}
1608	if (bd_page) {
1609		lock_page(bd_page);
1610		clear_page_dirty_for_io(bd_page);
1611		set_page_writeback(bd_page);
1612		unlock_page(bd_page);
1613	}
1614	nilfs_begin_page_io(fs_page);
1615}
1616
1617static int nilfs_segctor_write(struct nilfs_sc_info *sci,
1618			       struct the_nilfs *nilfs)
1619{
1620	int ret;
1621
1622	ret = nilfs_write_logs(&sci->sc_segbufs, nilfs);
1623	list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs);
1624	return ret;
1625}
1626
1627static void nilfs_end_page_io(struct page *page, int err)
1628{
1629	if (!page)
1630		return;
1631
1632	if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
 
1633		/*
1634		 * For b-tree node pages, this function may be called twice
1635		 * or more because they might be split in a segment.
1636		 */
1637		if (PageDirty(page)) {
1638			/*
1639			 * For pages holding split b-tree node buffers, dirty
1640			 * flag on the buffers may be cleared discretely.
1641			 * In that case, the page is once redirtied for
1642			 * remaining buffers, and it must be cancelled if
1643			 * all the buffers get cleaned later.
1644			 */
1645			lock_page(page);
1646			if (nilfs_page_buffers_clean(page))
1647				__nilfs_clear_page_dirty(page);
1648			unlock_page(page);
1649		}
1650		return;
1651	}
1652
1653	if (!err) {
1654		if (!nilfs_page_buffers_clean(page))
1655			__set_page_dirty_nobuffers(page);
1656		ClearPageError(page);
1657	} else {
1658		__set_page_dirty_nobuffers(page);
1659		SetPageError(page);
1660	}
1661
1662	end_page_writeback(page);
1663}
1664
1665static void nilfs_abort_logs(struct list_head *logs, int err)
1666{
1667	struct nilfs_segment_buffer *segbuf;
1668	struct page *bd_page = NULL, *fs_page = NULL;
1669	struct buffer_head *bh;
1670
1671	if (list_empty(logs))
1672		return;
1673
1674	list_for_each_entry(segbuf, logs, sb_list) {
1675		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1676				    b_assoc_buffers) {
1677			if (bh->b_page != bd_page) {
1678				if (bd_page)
1679					end_page_writeback(bd_page);
1680				bd_page = bh->b_page;
 
1681			}
1682		}
1683
1684		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1685				    b_assoc_buffers) {
1686			if (bh == segbuf->sb_super_root) {
1687				if (bh->b_page != bd_page) {
1688					end_page_writeback(bd_page);
1689					bd_page = bh->b_page;
 
1690				}
1691				break;
1692			}
1693			if (bh->b_page != fs_page) {
1694				nilfs_end_page_io(fs_page, err);
1695				fs_page = bh->b_page;
 
1696			}
1697		}
1698	}
1699	if (bd_page)
1700		end_page_writeback(bd_page);
1701
1702	nilfs_end_page_io(fs_page, err);
1703}
1704
1705static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci,
1706					     struct the_nilfs *nilfs, int err)
1707{
1708	LIST_HEAD(logs);
1709	int ret;
1710
1711	list_splice_tail_init(&sci->sc_write_logs, &logs);
1712	ret = nilfs_wait_on_logs(&logs);
1713	nilfs_abort_logs(&logs, ret ? : err);
1714
1715	list_splice_tail_init(&sci->sc_segbufs, &logs);
1716	nilfs_cancel_segusage(&logs, nilfs->ns_sufile);
1717	nilfs_free_incomplete_logs(&logs, nilfs);
1718
1719	if (sci->sc_stage.flags & NILFS_CF_SUFREED) {
1720		ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile,
1721						sci->sc_freesegs,
1722						sci->sc_nfreesegs,
1723						NULL);
1724		WARN_ON(ret); /* do not happen */
1725	}
1726
1727	nilfs_destroy_logs(&logs);
1728}
1729
1730static void nilfs_set_next_segment(struct the_nilfs *nilfs,
1731				   struct nilfs_segment_buffer *segbuf)
1732{
1733	nilfs->ns_segnum = segbuf->sb_segnum;
1734	nilfs->ns_nextnum = segbuf->sb_nextnum;
1735	nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start
1736		+ segbuf->sb_sum.nblocks;
1737	nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq;
1738	nilfs->ns_ctime = segbuf->sb_sum.ctime;
1739}
1740
1741static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci)
1742{
1743	struct nilfs_segment_buffer *segbuf;
1744	struct page *bd_page = NULL, *fs_page = NULL;
1745	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1746	int update_sr = false;
1747
1748	list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) {
1749		struct buffer_head *bh;
1750
1751		list_for_each_entry(bh, &segbuf->sb_segsum_buffers,
1752				    b_assoc_buffers) {
1753			set_buffer_uptodate(bh);
1754			clear_buffer_dirty(bh);
1755			if (bh->b_page != bd_page) {
1756				if (bd_page)
1757					end_page_writeback(bd_page);
1758				bd_page = bh->b_page;
1759			}
1760		}
1761		/*
1762		 * We assume that the buffers which belong to the same page
1763		 * continue over the buffer list.
1764		 * Under this assumption, the last BHs of pages is
1765		 * identifiable by the discontinuity of bh->b_page
1766		 * (page != fs_page).
1767		 *
1768		 * For B-tree node blocks, however, this assumption is not
1769		 * guaranteed.  The cleanup code of B-tree node pages needs
1770		 * special care.
1771		 */
1772		list_for_each_entry(bh, &segbuf->sb_payload_buffers,
1773				    b_assoc_buffers) {
1774			set_buffer_uptodate(bh);
1775			clear_buffer_dirty(bh);
1776			clear_buffer_delay(bh);
1777			clear_buffer_nilfs_volatile(bh);
1778			clear_buffer_nilfs_redirected(bh);
 
1779			if (bh == segbuf->sb_super_root) {
1780				if (bh->b_page != bd_page) {
1781					end_page_writeback(bd_page);
1782					bd_page = bh->b_page;
 
 
1783				}
1784				update_sr = true;
1785				break;
1786			}
1787			if (bh->b_page != fs_page) {
1788				nilfs_end_page_io(fs_page, 0);
1789				fs_page = bh->b_page;
 
1790			}
1791		}
1792
1793		if (!nilfs_segbuf_simplex(segbuf)) {
1794			if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) {
1795				set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1796				sci->sc_lseg_stime = jiffies;
1797			}
1798			if (segbuf->sb_sum.flags & NILFS_SS_LOGEND)
1799				clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
1800		}
1801	}
1802	/*
1803	 * Since pages may continue over multiple segment buffers,
1804	 * end of the last page must be checked outside of the loop.
1805	 */
1806	if (bd_page)
1807		end_page_writeback(bd_page);
1808
1809	nilfs_end_page_io(fs_page, 0);
1810
1811	nilfs_drop_collected_inodes(&sci->sc_dirty_files);
1812
1813	if (nilfs_doing_gc())
1814		nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
1815	else
1816		nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
1817
1818	sci->sc_nblk_inc += sci->sc_nblk_this_inc;
1819
1820	segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs);
1821	nilfs_set_next_segment(nilfs, segbuf);
1822
1823	if (update_sr) {
 
1824		nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
1825				       segbuf->sb_sum.seg_seq, nilfs->ns_cno++);
1826
1827		clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags);
1828		clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1829		set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1830		nilfs_segctor_clear_metadata_dirty(sci);
1831	} else
1832		clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
1833}
1834
1835static int nilfs_segctor_wait(struct nilfs_sc_info *sci)
1836{
1837	int ret;
1838
1839	ret = nilfs_wait_on_logs(&sci->sc_write_logs);
1840	if (!ret) {
1841		nilfs_segctor_complete_write(sci);
1842		nilfs_destroy_logs(&sci->sc_write_logs);
1843	}
1844	return ret;
1845}
1846
1847static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci,
1848					     struct the_nilfs *nilfs)
1849{
1850	struct nilfs_inode_info *ii, *n;
1851	struct inode *ifile = sci->sc_root->ifile;
1852
1853	spin_lock(&nilfs->ns_inode_lock);
1854 retry:
1855	list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) {
1856		if (!ii->i_bh) {
1857			struct buffer_head *ibh;
1858			int err;
1859
1860			spin_unlock(&nilfs->ns_inode_lock);
1861			err = nilfs_ifile_get_inode_block(
1862				ifile, ii->vfs_inode.i_ino, &ibh);
1863			if (unlikely(err)) {
1864				nilfs_warning(sci->sc_super, __func__,
1865					      "failed to get inode block.\n");
 
1866				return err;
1867			}
1868			mark_buffer_dirty(ibh);
1869			nilfs_mdt_mark_dirty(ifile);
1870			spin_lock(&nilfs->ns_inode_lock);
1871			if (likely(!ii->i_bh))
1872				ii->i_bh = ibh;
1873			else
1874				brelse(ibh);
1875			goto retry;
1876		}
1877
 
 
 
 
1878		clear_bit(NILFS_I_QUEUED, &ii->i_state);
1879		set_bit(NILFS_I_BUSY, &ii->i_state);
1880		list_move_tail(&ii->i_dirty, &sci->sc_dirty_files);
1881	}
1882	spin_unlock(&nilfs->ns_inode_lock);
1883
1884	return 0;
1885}
1886
1887static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci,
1888					     struct the_nilfs *nilfs)
1889{
1890	struct nilfs_transaction_info *ti = current->journal_info;
1891	struct nilfs_inode_info *ii, *n;
 
 
1892
1893	spin_lock(&nilfs->ns_inode_lock);
1894	list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) {
1895		if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) ||
1896		    test_bit(NILFS_I_DIRTY, &ii->i_state))
1897			continue;
1898
1899		clear_bit(NILFS_I_BUSY, &ii->i_state);
1900		brelse(ii->i_bh);
1901		ii->i_bh = NULL;
1902		list_move_tail(&ii->i_dirty, &ti->ti_garbage);
 
 
 
 
 
 
 
 
 
 
 
 
1903	}
1904	spin_unlock(&nilfs->ns_inode_lock);
 
 
 
1905}
1906
1907/*
1908 * Main procedure of segment constructor
1909 */
1910static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
1911{
1912	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
1913	int err;
1914
1915	sci->sc_stage.scnt = NILFS_ST_INIT;
 
 
 
1916	sci->sc_cno = nilfs->ns_cno;
1917
1918	err = nilfs_segctor_collect_dirty_files(sci, nilfs);
1919	if (unlikely(err))
1920		goto out;
1921
1922	if (nilfs_test_metadata_dirty(nilfs, sci->sc_root))
1923		set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
1924
1925	if (nilfs_segctor_clean(sci))
1926		goto out;
1927
1928	do {
1929		sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK;
1930
1931		err = nilfs_segctor_begin_construction(sci, nilfs);
1932		if (unlikely(err))
1933			goto out;
1934
1935		/* Update time stamp */
1936		sci->sc_seg_ctime = get_seconds();
1937
1938		err = nilfs_segctor_collect(sci, nilfs, mode);
1939		if (unlikely(err))
1940			goto failed;
1941
1942		/* Avoid empty segment */
1943		if (sci->sc_stage.scnt == NILFS_ST_DONE &&
1944		    nilfs_segbuf_empty(sci->sc_curseg)) {
1945			nilfs_segctor_abort_construction(sci, nilfs, 1);
1946			goto out;
1947		}
1948
1949		err = nilfs_segctor_assign(sci, mode);
1950		if (unlikely(err))
1951			goto failed;
1952
1953		if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1954			nilfs_segctor_fill_in_file_bmap(sci);
1955
1956		if (mode == SC_LSEG_SR &&
1957		    sci->sc_stage.scnt >= NILFS_ST_CPFILE) {
1958			err = nilfs_segctor_fill_in_checkpoint(sci);
1959			if (unlikely(err))
1960				goto failed_to_write;
1961
1962			nilfs_segctor_fill_in_super_root(sci, nilfs);
1963		}
1964		nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
1965
1966		/* Write partial segments */
1967		nilfs_segctor_prepare_write(sci);
1968
1969		nilfs_add_checksums_on_logs(&sci->sc_segbufs,
1970					    nilfs->ns_crc_seed);
1971
1972		err = nilfs_segctor_write(sci, nilfs);
1973		if (unlikely(err))
1974			goto failed_to_write;
1975
1976		if (sci->sc_stage.scnt == NILFS_ST_DONE ||
1977		    nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) {
1978			/*
1979			 * At this point, we avoid double buffering
1980			 * for blocksize < pagesize because page dirty
1981			 * flag is turned off during write and dirty
1982			 * buffers are not properly collected for
1983			 * pages crossing over segments.
1984			 */
1985			err = nilfs_segctor_wait(sci);
1986			if (err)
1987				goto failed_to_write;
1988		}
1989	} while (sci->sc_stage.scnt != NILFS_ST_DONE);
1990
1991 out:
1992	nilfs_segctor_drop_written_files(sci, nilfs);
1993	return err;
1994
1995 failed_to_write:
1996	if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
1997		nilfs_redirty_inodes(&sci->sc_dirty_files);
1998
1999 failed:
2000	if (nilfs_doing_gc())
2001		nilfs_redirty_inodes(&sci->sc_gc_inodes);
2002	nilfs_segctor_abort_construction(sci, nilfs, err);
2003	goto out;
2004}
2005
2006/**
2007 * nilfs_segctor_start_timer - set timer of background write
2008 * @sci: nilfs_sc_info
2009 *
2010 * If the timer has already been set, it ignores the new request.
2011 * This function MUST be called within a section locking the segment
2012 * semaphore.
2013 */
2014static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci)
2015{
2016	spin_lock(&sci->sc_state_lock);
2017	if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) {
2018		sci->sc_timer.expires = jiffies + sci->sc_interval;
2019		add_timer(&sci->sc_timer);
2020		sci->sc_state |= NILFS_SEGCTOR_COMMIT;
2021	}
2022	spin_unlock(&sci->sc_state_lock);
2023}
2024
2025static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn)
2026{
2027	spin_lock(&sci->sc_state_lock);
2028	if (!(sci->sc_flush_request & (1 << bn))) {
2029		unsigned long prev_req = sci->sc_flush_request;
2030
2031		sci->sc_flush_request |= (1 << bn);
2032		if (!prev_req)
2033			wake_up(&sci->sc_wait_daemon);
2034	}
2035	spin_unlock(&sci->sc_state_lock);
2036}
2037
2038/**
2039 * nilfs_flush_segment - trigger a segment construction for resource control
2040 * @sb: super block
2041 * @ino: inode number of the file to be flushed out.
2042 */
2043void nilfs_flush_segment(struct super_block *sb, ino_t ino)
2044{
2045	struct the_nilfs *nilfs = sb->s_fs_info;
2046	struct nilfs_sc_info *sci = nilfs->ns_writer;
2047
2048	if (!sci || nilfs_doing_construction())
2049		return;
2050	nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
2051					/* assign bit 0 to data files */
2052}
2053
2054struct nilfs_segctor_wait_request {
2055	wait_queue_t	wq;
2056	__u32		seq;
2057	int		err;
2058	atomic_t	done;
2059};
2060
2061static int nilfs_segctor_sync(struct nilfs_sc_info *sci)
2062{
2063	struct nilfs_segctor_wait_request wait_req;
2064	int err = 0;
2065
2066	spin_lock(&sci->sc_state_lock);
2067	init_wait(&wait_req.wq);
2068	wait_req.err = 0;
2069	atomic_set(&wait_req.done, 0);
2070	wait_req.seq = ++sci->sc_seq_request;
2071	spin_unlock(&sci->sc_state_lock);
2072
2073	init_waitqueue_entry(&wait_req.wq, current);
2074	add_wait_queue(&sci->sc_wait_request, &wait_req.wq);
2075	set_current_state(TASK_INTERRUPTIBLE);
2076	wake_up(&sci->sc_wait_daemon);
2077
2078	for (;;) {
2079		if (atomic_read(&wait_req.done)) {
2080			err = wait_req.err;
2081			break;
2082		}
2083		if (!signal_pending(current)) {
2084			schedule();
2085			continue;
2086		}
2087		err = -ERESTARTSYS;
2088		break;
2089	}
2090	finish_wait(&sci->sc_wait_request, &wait_req.wq);
2091	return err;
2092}
2093
2094static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err)
2095{
2096	struct nilfs_segctor_wait_request *wrq, *n;
2097	unsigned long flags;
2098
2099	spin_lock_irqsave(&sci->sc_wait_request.lock, flags);
2100	list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list,
2101				 wq.task_list) {
2102		if (!atomic_read(&wrq->done) &&
2103		    nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) {
2104			wrq->err = err;
2105			atomic_set(&wrq->done, 1);
2106		}
2107		if (atomic_read(&wrq->done)) {
2108			wrq->wq.func(&wrq->wq,
2109				     TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE,
2110				     0, NULL);
2111		}
2112	}
2113	spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags);
2114}
2115
2116/**
2117 * nilfs_construct_segment - construct a logical segment
2118 * @sb: super block
2119 *
2120 * Return Value: On success, 0 is retured. On errors, one of the following
2121 * negative error code is returned.
2122 *
2123 * %-EROFS - Read only filesystem.
2124 *
2125 * %-EIO - I/O error
2126 *
2127 * %-ENOSPC - No space left on device (only in a panic state).
2128 *
2129 * %-ERESTARTSYS - Interrupted.
2130 *
2131 * %-ENOMEM - Insufficient memory available.
2132 */
2133int nilfs_construct_segment(struct super_block *sb)
2134{
2135	struct the_nilfs *nilfs = sb->s_fs_info;
2136	struct nilfs_sc_info *sci = nilfs->ns_writer;
2137	struct nilfs_transaction_info *ti;
2138	int err;
2139
2140	if (!sci)
2141		return -EROFS;
2142
2143	/* A call inside transactions causes a deadlock. */
2144	BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC);
2145
2146	err = nilfs_segctor_sync(sci);
2147	return err;
2148}
2149
2150/**
2151 * nilfs_construct_dsync_segment - construct a data-only logical segment
2152 * @sb: super block
2153 * @inode: inode whose data blocks should be written out
2154 * @start: start byte offset
2155 * @end: end byte offset (inclusive)
2156 *
2157 * Return Value: On success, 0 is retured. On errors, one of the following
2158 * negative error code is returned.
2159 *
2160 * %-EROFS - Read only filesystem.
2161 *
2162 * %-EIO - I/O error
2163 *
2164 * %-ENOSPC - No space left on device (only in a panic state).
2165 *
2166 * %-ERESTARTSYS - Interrupted.
2167 *
2168 * %-ENOMEM - Insufficient memory available.
2169 */
2170int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode,
2171				  loff_t start, loff_t end)
2172{
2173	struct the_nilfs *nilfs = sb->s_fs_info;
2174	struct nilfs_sc_info *sci = nilfs->ns_writer;
2175	struct nilfs_inode_info *ii;
2176	struct nilfs_transaction_info ti;
2177	int err = 0;
2178
2179	if (!sci)
2180		return -EROFS;
2181
2182	nilfs_transaction_lock(sb, &ti, 0);
2183
2184	ii = NILFS_I(inode);
2185	if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
2186	    nilfs_test_opt(nilfs, STRICT_ORDER) ||
2187	    test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2188	    nilfs_discontinued(nilfs)) {
2189		nilfs_transaction_unlock(sb);
2190		err = nilfs_segctor_sync(sci);
2191		return err;
2192	}
2193
2194	spin_lock(&nilfs->ns_inode_lock);
2195	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
2196	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
2197		spin_unlock(&nilfs->ns_inode_lock);
2198		nilfs_transaction_unlock(sb);
2199		return 0;
2200	}
2201	spin_unlock(&nilfs->ns_inode_lock);
2202	sci->sc_dsync_inode = ii;
2203	sci->sc_dsync_start = start;
2204	sci->sc_dsync_end = end;
2205
2206	err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
 
 
2207
2208	nilfs_transaction_unlock(sb);
2209	return err;
2210}
2211
2212#define FLUSH_FILE_BIT	(0x1) /* data file only */
2213#define FLUSH_DAT_BIT	(1 << NILFS_DAT_INO) /* DAT only */
2214
2215/**
2216 * nilfs_segctor_accept - record accepted sequence count of log-write requests
2217 * @sci: segment constructor object
2218 */
2219static void nilfs_segctor_accept(struct nilfs_sc_info *sci)
2220{
2221	spin_lock(&sci->sc_state_lock);
2222	sci->sc_seq_accepted = sci->sc_seq_request;
2223	spin_unlock(&sci->sc_state_lock);
2224	del_timer_sync(&sci->sc_timer);
2225}
2226
2227/**
2228 * nilfs_segctor_notify - notify the result of request to caller threads
2229 * @sci: segment constructor object
2230 * @mode: mode of log forming
2231 * @err: error code to be notified
2232 */
2233static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err)
2234{
2235	/* Clear requests (even when the construction failed) */
2236	spin_lock(&sci->sc_state_lock);
2237
2238	if (mode == SC_LSEG_SR) {
2239		sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
2240		sci->sc_seq_done = sci->sc_seq_accepted;
2241		nilfs_segctor_wakeup(sci, err);
2242		sci->sc_flush_request = 0;
2243	} else {
2244		if (mode == SC_FLUSH_FILE)
2245			sci->sc_flush_request &= ~FLUSH_FILE_BIT;
2246		else if (mode == SC_FLUSH_DAT)
2247			sci->sc_flush_request &= ~FLUSH_DAT_BIT;
2248
2249		/* re-enable timer if checkpoint creation was not done */
2250		if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2251		    time_before(jiffies, sci->sc_timer.expires))
2252			add_timer(&sci->sc_timer);
2253	}
2254	spin_unlock(&sci->sc_state_lock);
2255}
2256
2257/**
2258 * nilfs_segctor_construct - form logs and write them to disk
2259 * @sci: segment constructor object
2260 * @mode: mode of log forming
2261 */
2262static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode)
2263{
2264	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2265	struct nilfs_super_block **sbp;
2266	int err = 0;
2267
2268	nilfs_segctor_accept(sci);
2269
2270	if (nilfs_discontinued(nilfs))
2271		mode = SC_LSEG_SR;
2272	if (!nilfs_segctor_confirm(sci))
2273		err = nilfs_segctor_do_construct(sci, mode);
2274
2275	if (likely(!err)) {
2276		if (mode != SC_FLUSH_DAT)
2277			atomic_set(&nilfs->ns_ndirtyblks, 0);
2278		if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) &&
2279		    nilfs_discontinued(nilfs)) {
2280			down_write(&nilfs->ns_sem);
2281			err = -EIO;
2282			sbp = nilfs_prepare_super(sci->sc_super,
2283						  nilfs_sb_will_flip(nilfs));
2284			if (likely(sbp)) {
2285				nilfs_set_log_cursor(sbp[0], nilfs);
2286				err = nilfs_commit_super(sci->sc_super,
2287							 NILFS_SB_COMMIT);
2288			}
2289			up_write(&nilfs->ns_sem);
2290		}
2291	}
2292
2293	nilfs_segctor_notify(sci, mode, err);
2294	return err;
2295}
2296
2297static void nilfs_construction_timeout(unsigned long data)
2298{
2299	struct task_struct *p = (struct task_struct *)data;
2300	wake_up_process(p);
 
2301}
2302
2303static void
2304nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head)
2305{
2306	struct nilfs_inode_info *ii, *n;
2307
2308	list_for_each_entry_safe(ii, n, head, i_dirty) {
2309		if (!test_bit(NILFS_I_UPDATED, &ii->i_state))
2310			continue;
2311		list_del_init(&ii->i_dirty);
 
 
2312		iput(&ii->vfs_inode);
2313	}
2314}
2315
2316int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv,
2317			 void **kbufs)
2318{
2319	struct the_nilfs *nilfs = sb->s_fs_info;
2320	struct nilfs_sc_info *sci = nilfs->ns_writer;
2321	struct nilfs_transaction_info ti;
2322	int err;
2323
2324	if (unlikely(!sci))
2325		return -EROFS;
2326
2327	nilfs_transaction_lock(sb, &ti, 1);
2328
2329	err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat);
2330	if (unlikely(err))
2331		goto out_unlock;
2332
2333	err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs);
2334	if (unlikely(err)) {
2335		nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat);
2336		goto out_unlock;
2337	}
2338
2339	sci->sc_freesegs = kbufs[4];
2340	sci->sc_nfreesegs = argv[4].v_nmembs;
2341	list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes);
2342
2343	for (;;) {
2344		err = nilfs_segctor_construct(sci, SC_LSEG_SR);
2345		nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
2346
2347		if (likely(!err))
2348			break;
2349
2350		nilfs_warning(sb, __func__,
2351			      "segment construction failed. (err=%d)", err);
2352		set_current_state(TASK_INTERRUPTIBLE);
2353		schedule_timeout(sci->sc_interval);
2354	}
2355	if (nilfs_test_opt(nilfs, DISCARD)) {
2356		int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs,
2357						 sci->sc_nfreesegs);
2358		if (ret) {
2359			printk(KERN_WARNING
2360			       "NILFS warning: error %d on discard request, "
2361			       "turning discards off for the device\n", ret);
2362			nilfs_clear_opt(nilfs, DISCARD);
2363		}
2364	}
2365
2366 out_unlock:
2367	sci->sc_freesegs = NULL;
2368	sci->sc_nfreesegs = 0;
2369	nilfs_mdt_clear_shadow_map(nilfs->ns_dat);
2370	nilfs_transaction_unlock(sb);
2371	return err;
2372}
2373
2374static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
2375{
2376	struct nilfs_transaction_info ti;
2377
2378	nilfs_transaction_lock(sci->sc_super, &ti, 0);
2379	nilfs_segctor_construct(sci, mode);
2380
2381	/*
2382	 * Unclosed segment should be retried.  We do this using sc_timer.
2383	 * Timeout of sc_timer will invoke complete construction which leads
2384	 * to close the current logical segment.
2385	 */
2386	if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags))
2387		nilfs_segctor_start_timer(sci);
2388
2389	nilfs_transaction_unlock(sci->sc_super);
2390}
2391
2392static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci)
2393{
2394	int mode = 0;
2395	int err;
2396
2397	spin_lock(&sci->sc_state_lock);
2398	mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ?
2399		SC_FLUSH_DAT : SC_FLUSH_FILE;
2400	spin_unlock(&sci->sc_state_lock);
2401
2402	if (mode) {
2403		err = nilfs_segctor_do_construct(sci, mode);
2404
2405		spin_lock(&sci->sc_state_lock);
2406		sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ?
2407			~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT;
2408		spin_unlock(&sci->sc_state_lock);
2409	}
2410	clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags);
2411}
2412
2413static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci)
2414{
2415	if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
2416	    time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) {
2417		if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT))
2418			return SC_FLUSH_FILE;
2419		else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT))
2420			return SC_FLUSH_DAT;
2421	}
2422	return SC_LSEG_SR;
2423}
2424
2425/**
2426 * nilfs_segctor_thread - main loop of the segment constructor thread.
2427 * @arg: pointer to a struct nilfs_sc_info.
2428 *
2429 * nilfs_segctor_thread() initializes a timer and serves as a daemon
2430 * to execute segment constructions.
2431 */
2432static int nilfs_segctor_thread(void *arg)
2433{
2434	struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg;
2435	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2436	int timeout = 0;
2437
2438	sci->sc_timer.data = (unsigned long)current;
2439	sci->sc_timer.function = nilfs_construction_timeout;
2440
2441	/* start sync. */
2442	sci->sc_task = current;
2443	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */
2444	printk(KERN_INFO
2445	       "segctord starting. Construction interval = %lu seconds, "
2446	       "CP frequency < %lu seconds\n",
2447	       sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ);
2448
 
2449	spin_lock(&sci->sc_state_lock);
2450 loop:
2451	for (;;) {
2452		int mode;
2453
2454		if (sci->sc_state & NILFS_SEGCTOR_QUIT)
2455			goto end_thread;
2456
2457		if (timeout || sci->sc_seq_request != sci->sc_seq_done)
2458			mode = SC_LSEG_SR;
2459		else if (!sci->sc_flush_request)
 
 
2460			break;
2461		else
2462			mode = nilfs_segctor_flush_mode(sci);
2463
2464		spin_unlock(&sci->sc_state_lock);
2465		nilfs_segctor_thread_construct(sci, mode);
2466		spin_lock(&sci->sc_state_lock);
2467		timeout = 0;
2468	}
2469
2470
2471	if (freezing(current)) {
2472		spin_unlock(&sci->sc_state_lock);
2473		refrigerator();
2474		spin_lock(&sci->sc_state_lock);
2475	} else {
2476		DEFINE_WAIT(wait);
2477		int should_sleep = 1;
2478
2479		prepare_to_wait(&sci->sc_wait_daemon, &wait,
2480				TASK_INTERRUPTIBLE);
2481
2482		if (sci->sc_seq_request != sci->sc_seq_done)
2483			should_sleep = 0;
2484		else if (sci->sc_flush_request)
2485			should_sleep = 0;
2486		else if (sci->sc_state & NILFS_SEGCTOR_COMMIT)
2487			should_sleep = time_before(jiffies,
2488					sci->sc_timer.expires);
2489
2490		if (should_sleep) {
2491			spin_unlock(&sci->sc_state_lock);
2492			schedule();
2493			spin_lock(&sci->sc_state_lock);
2494		}
2495		finish_wait(&sci->sc_wait_daemon, &wait);
2496		timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) &&
2497			   time_after_eq(jiffies, sci->sc_timer.expires));
2498
2499		if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs))
2500			set_nilfs_discontinued(nilfs);
2501	}
2502	goto loop;
2503
2504 end_thread:
2505	spin_unlock(&sci->sc_state_lock);
2506
2507	/* end sync. */
2508	sci->sc_task = NULL;
2509	wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */
 
2510	return 0;
2511}
2512
2513static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci)
2514{
2515	struct task_struct *t;
2516
2517	t = kthread_run(nilfs_segctor_thread, sci, "segctord");
2518	if (IS_ERR(t)) {
2519		int err = PTR_ERR(t);
2520
2521		printk(KERN_ERR "NILFS: error %d creating segctord thread\n",
2522		       err);
2523		return err;
2524	}
2525	wait_event(sci->sc_wait_task, sci->sc_task != NULL);
2526	return 0;
2527}
2528
2529static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci)
2530	__acquires(&sci->sc_state_lock)
2531	__releases(&sci->sc_state_lock)
2532{
2533	sci->sc_state |= NILFS_SEGCTOR_QUIT;
2534
2535	while (sci->sc_task) {
2536		wake_up(&sci->sc_wait_daemon);
2537		spin_unlock(&sci->sc_state_lock);
2538		wait_event(sci->sc_wait_task, sci->sc_task == NULL);
2539		spin_lock(&sci->sc_state_lock);
2540	}
2541}
2542
2543/*
2544 * Setup & clean-up functions
2545 */
2546static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb,
2547					       struct nilfs_root *root)
2548{
2549	struct the_nilfs *nilfs = sb->s_fs_info;
2550	struct nilfs_sc_info *sci;
2551
2552	sci = kzalloc(sizeof(*sci), GFP_KERNEL);
2553	if (!sci)
2554		return NULL;
2555
2556	sci->sc_super = sb;
2557
2558	nilfs_get_root(root);
2559	sci->sc_root = root;
2560
2561	init_waitqueue_head(&sci->sc_wait_request);
2562	init_waitqueue_head(&sci->sc_wait_daemon);
2563	init_waitqueue_head(&sci->sc_wait_task);
2564	spin_lock_init(&sci->sc_state_lock);
2565	INIT_LIST_HEAD(&sci->sc_dirty_files);
2566	INIT_LIST_HEAD(&sci->sc_segbufs);
2567	INIT_LIST_HEAD(&sci->sc_write_logs);
2568	INIT_LIST_HEAD(&sci->sc_gc_inodes);
2569	init_timer(&sci->sc_timer);
 
 
2570
2571	sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT;
2572	sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ;
2573	sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK;
2574
2575	if (nilfs->ns_interval)
2576		sci->sc_interval = HZ * nilfs->ns_interval;
2577	if (nilfs->ns_watermark)
2578		sci->sc_watermark = nilfs->ns_watermark;
2579	return sci;
2580}
2581
2582static void nilfs_segctor_write_out(struct nilfs_sc_info *sci)
2583{
2584	int ret, retrycount = NILFS_SC_CLEANUP_RETRY;
2585
2586	/* The segctord thread was stopped and its timer was removed.
2587	   But some tasks remain. */
 
 
2588	do {
2589		struct nilfs_transaction_info ti;
2590
2591		nilfs_transaction_lock(sci->sc_super, &ti, 0);
2592		ret = nilfs_segctor_construct(sci, SC_LSEG_SR);
2593		nilfs_transaction_unlock(sci->sc_super);
2594
2595	} while (ret && retrycount-- > 0);
 
 
2596}
2597
2598/**
2599 * nilfs_segctor_destroy - destroy the segment constructor.
2600 * @sci: nilfs_sc_info
2601 *
2602 * nilfs_segctor_destroy() kills the segctord thread and frees
2603 * the nilfs_sc_info struct.
2604 * Caller must hold the segment semaphore.
2605 */
2606static void nilfs_segctor_destroy(struct nilfs_sc_info *sci)
2607{
2608	struct the_nilfs *nilfs = sci->sc_super->s_fs_info;
2609	int flag;
2610
2611	up_write(&nilfs->ns_segctor_sem);
2612
2613	spin_lock(&sci->sc_state_lock);
2614	nilfs_segctor_kill_thread(sci);
2615	flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request
2616		|| sci->sc_seq_request != sci->sc_seq_done);
2617	spin_unlock(&sci->sc_state_lock);
2618
 
 
 
2619	if (flag || !nilfs_segctor_confirm(sci))
2620		nilfs_segctor_write_out(sci);
2621
2622	if (!list_empty(&sci->sc_dirty_files)) {
2623		nilfs_warning(sci->sc_super, __func__,
2624			      "dirty file(s) after the final construction\n");
2625		nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1);
2626	}
2627
 
 
 
 
 
 
2628	WARN_ON(!list_empty(&sci->sc_segbufs));
2629	WARN_ON(!list_empty(&sci->sc_write_logs));
2630
2631	nilfs_put_root(sci->sc_root);
2632
2633	down_write(&nilfs->ns_segctor_sem);
2634
2635	del_timer_sync(&sci->sc_timer);
2636	kfree(sci);
2637}
2638
2639/**
2640 * nilfs_attach_log_writer - attach log writer
2641 * @sb: super block instance
2642 * @root: root object of the current filesystem tree
2643 *
2644 * This allocates a log writer object, initializes it, and starts the
2645 * log writer.
2646 *
2647 * Return Value: On success, 0 is returned. On error, one of the following
2648 * negative error code is returned.
2649 *
2650 * %-ENOMEM - Insufficient memory available.
2651 */
2652int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root)
2653{
2654	struct the_nilfs *nilfs = sb->s_fs_info;
2655	int err;
2656
2657	if (nilfs->ns_writer) {
2658		/*
2659		 * This happens if the filesystem was remounted
2660		 * read/write after nilfs_error degenerated it into a
2661		 * read-only mount.
 
2662		 */
2663		nilfs_detach_log_writer(sb);
2664	}
2665
2666	nilfs->ns_writer = nilfs_segctor_new(sb, root);
2667	if (!nilfs->ns_writer)
2668		return -ENOMEM;
2669
 
 
2670	err = nilfs_segctor_start_thread(nilfs->ns_writer);
2671	if (err) {
2672		kfree(nilfs->ns_writer);
2673		nilfs->ns_writer = NULL;
2674	}
2675	return err;
2676}
2677
2678/**
2679 * nilfs_detach_log_writer - destroy log writer
2680 * @sb: super block instance
2681 *
2682 * This kills log writer daemon, frees the log writer object, and
2683 * destroys list of dirty files.
2684 */
2685void nilfs_detach_log_writer(struct super_block *sb)
2686{
2687	struct the_nilfs *nilfs = sb->s_fs_info;
2688	LIST_HEAD(garbage_list);
2689
2690	down_write(&nilfs->ns_segctor_sem);
2691	if (nilfs->ns_writer) {
2692		nilfs_segctor_destroy(nilfs->ns_writer);
2693		nilfs->ns_writer = NULL;
2694	}
 
2695
2696	/* Force to free the list of dirty files */
2697	spin_lock(&nilfs->ns_inode_lock);
2698	if (!list_empty(&nilfs->ns_dirty_files)) {
2699		list_splice_init(&nilfs->ns_dirty_files, &garbage_list);
2700		nilfs_warning(sb, __func__,
2701			      "Hit dirty file after stopped log writer\n");
2702	}
2703	spin_unlock(&nilfs->ns_inode_lock);
2704	up_write(&nilfs->ns_segctor_sem);
2705
2706	nilfs_dispose_list(nilfs, &garbage_list, 1);
 
2707}