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v4.17
 
   1/*
   2 * inode.c - NILFS inode operations.
   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 * Written by Ryusuke Konishi.
  17 *
  18 */
  19
  20#include <linux/buffer_head.h>
  21#include <linux/gfp.h>
  22#include <linux/mpage.h>
  23#include <linux/pagemap.h>
  24#include <linux/writeback.h>
  25#include <linux/uio.h>
  26#include "nilfs.h"
  27#include "btnode.h"
  28#include "segment.h"
  29#include "page.h"
  30#include "mdt.h"
  31#include "cpfile.h"
  32#include "ifile.h"
  33
  34/**
  35 * struct nilfs_iget_args - arguments used during comparison between inodes
  36 * @ino: inode number
  37 * @cno: checkpoint number
  38 * @root: pointer on NILFS root object (mounted checkpoint)
  39 * @for_gc: inode for GC flag
  40 */
  41struct nilfs_iget_args {
  42	u64 ino;
  43	__u64 cno;
  44	struct nilfs_root *root;
  45	int for_gc;
  46};
  47
  48static int nilfs_iget_test(struct inode *inode, void *opaque);
  49
  50void nilfs_inode_add_blocks(struct inode *inode, int n)
  51{
  52	struct nilfs_root *root = NILFS_I(inode)->i_root;
  53
  54	inode_add_bytes(inode, i_blocksize(inode) * n);
  55	if (root)
  56		atomic64_add(n, &root->blocks_count);
  57}
  58
  59void nilfs_inode_sub_blocks(struct inode *inode, int n)
  60{
  61	struct nilfs_root *root = NILFS_I(inode)->i_root;
  62
  63	inode_sub_bytes(inode, i_blocksize(inode) * n);
  64	if (root)
  65		atomic64_sub(n, &root->blocks_count);
  66}
  67
  68/**
  69 * nilfs_get_block() - get a file block on the filesystem (callback function)
  70 * @inode - inode struct of the target file
  71 * @blkoff - file block number
  72 * @bh_result - buffer head to be mapped on
  73 * @create - indicate whether allocating the block or not when it has not
  74 *      been allocated yet.
  75 *
  76 * This function does not issue actual read request of the specified data
  77 * block. It is done by VFS.
  78 */
  79int nilfs_get_block(struct inode *inode, sector_t blkoff,
  80		    struct buffer_head *bh_result, int create)
  81{
  82	struct nilfs_inode_info *ii = NILFS_I(inode);
  83	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  84	__u64 blknum = 0;
  85	int err = 0, ret;
  86	unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  87
  88	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  89	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  90	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  91	if (ret >= 0) {	/* found */
  92		map_bh(bh_result, inode->i_sb, blknum);
  93		if (ret > 0)
  94			bh_result->b_size = (ret << inode->i_blkbits);
  95		goto out;
  96	}
  97	/* data block was not found */
  98	if (ret == -ENOENT && create) {
  99		struct nilfs_transaction_info ti;
 100
 101		bh_result->b_blocknr = 0;
 102		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
 103		if (unlikely(err))
 104			goto out;
 105		err = nilfs_bmap_insert(ii->i_bmap, blkoff,
 106					(unsigned long)bh_result);
 107		if (unlikely(err != 0)) {
 108			if (err == -EEXIST) {
 109				/*
 110				 * The get_block() function could be called
 111				 * from multiple callers for an inode.
 112				 * However, the page having this block must
 113				 * be locked in this case.
 114				 */
 115				nilfs_msg(inode->i_sb, KERN_WARNING,
 116					  "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 117					  __func__, inode->i_ino,
 118					  (unsigned long long)blkoff);
 119				err = 0;
 120			}
 121			nilfs_transaction_abort(inode->i_sb);
 122			goto out;
 123		}
 124		nilfs_mark_inode_dirty_sync(inode);
 125		nilfs_transaction_commit(inode->i_sb); /* never fails */
 126		/* Error handling should be detailed */
 127		set_buffer_new(bh_result);
 128		set_buffer_delay(bh_result);
 129		map_bh(bh_result, inode->i_sb, 0);
 130		/* Disk block number must be changed to proper value */
 131
 132	} else if (ret == -ENOENT) {
 133		/*
 134		 * not found is not error (e.g. hole); must return without
 135		 * the mapped state flag.
 136		 */
 137		;
 138	} else {
 139		err = ret;
 140	}
 141
 142 out:
 143	return err;
 144}
 145
 146/**
 147 * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 148 * address_space_operations.
 149 * @file - file struct of the file to be read
 150 * @page - the page to be read
 151 */
 152static int nilfs_readpage(struct file *file, struct page *page)
 153{
 154	return mpage_readpage(page, nilfs_get_block);
 155}
 156
 157/**
 158 * nilfs_readpages() - implement readpages() method of nilfs_aops {}
 159 * address_space_operations.
 160 * @file - file struct of the file to be read
 161 * @mapping - address_space struct used for reading multiple pages
 162 * @pages - the pages to be read
 163 * @nr_pages - number of pages to be read
 164 */
 165static int nilfs_readpages(struct file *file, struct address_space *mapping,
 166			   struct list_head *pages, unsigned int nr_pages)
 167{
 168	return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
 169}
 170
 171static int nilfs_writepages(struct address_space *mapping,
 172			    struct writeback_control *wbc)
 173{
 174	struct inode *inode = mapping->host;
 175	int err = 0;
 176
 177	if (sb_rdonly(inode->i_sb)) {
 178		nilfs_clear_dirty_pages(mapping, false);
 179		return -EROFS;
 180	}
 181
 182	if (wbc->sync_mode == WB_SYNC_ALL)
 183		err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 184						    wbc->range_start,
 185						    wbc->range_end);
 186	return err;
 187}
 188
 189static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 190{
 191	struct inode *inode = page->mapping->host;
 192	int err;
 193
 194	if (sb_rdonly(inode->i_sb)) {
 195		/*
 196		 * It means that filesystem was remounted in read-only
 197		 * mode because of error or metadata corruption. But we
 198		 * have dirty pages that try to be flushed in background.
 199		 * So, here we simply discard this dirty page.
 200		 */
 201		nilfs_clear_dirty_page(page, false);
 202		unlock_page(page);
 203		return -EROFS;
 204	}
 205
 206	redirty_page_for_writepage(wbc, page);
 207	unlock_page(page);
 208
 209	if (wbc->sync_mode == WB_SYNC_ALL) {
 210		err = nilfs_construct_segment(inode->i_sb);
 211		if (unlikely(err))
 212			return err;
 213	} else if (wbc->for_reclaim)
 214		nilfs_flush_segment(inode->i_sb, inode->i_ino);
 215
 216	return 0;
 217}
 218
 219static int nilfs_set_page_dirty(struct page *page)
 220{
 221	struct inode *inode = page->mapping->host;
 222	int ret = __set_page_dirty_nobuffers(page);
 223
 224	if (page_has_buffers(page)) {
 225		unsigned int nr_dirty = 0;
 226		struct buffer_head *bh, *head;
 227
 228		/*
 229		 * This page is locked by callers, and no other thread
 230		 * concurrently marks its buffers dirty since they are
 231		 * only dirtied through routines in fs/buffer.c in
 232		 * which call sites of mark_buffer_dirty are protected
 233		 * by page lock.
 234		 */
 235		bh = head = page_buffers(page);
 236		do {
 237			/* Do not mark hole blocks dirty */
 238			if (buffer_dirty(bh) || !buffer_mapped(bh))
 239				continue;
 240
 241			set_buffer_dirty(bh);
 242			nr_dirty++;
 243		} while (bh = bh->b_this_page, bh != head);
 244
 245		if (nr_dirty)
 246			nilfs_set_file_dirty(inode, nr_dirty);
 247	} else if (ret) {
 248		unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 249
 250		nilfs_set_file_dirty(inode, nr_dirty);
 251	}
 252	return ret;
 253}
 254
 255void nilfs_write_failed(struct address_space *mapping, loff_t to)
 256{
 257	struct inode *inode = mapping->host;
 258
 259	if (to > inode->i_size) {
 260		truncate_pagecache(inode, inode->i_size);
 261		nilfs_truncate(inode);
 262	}
 263}
 264
 265static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 266			     loff_t pos, unsigned len, unsigned flags,
 267			     struct page **pagep, void **fsdata)
 268
 269{
 270	struct inode *inode = mapping->host;
 271	int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 272
 273	if (unlikely(err))
 274		return err;
 275
 276	err = block_write_begin(mapping, pos, len, flags, pagep,
 277				nilfs_get_block);
 278	if (unlikely(err)) {
 279		nilfs_write_failed(mapping, pos + len);
 280		nilfs_transaction_abort(inode->i_sb);
 281	}
 282	return err;
 283}
 284
 285static int nilfs_write_end(struct file *file, struct address_space *mapping,
 286			   loff_t pos, unsigned len, unsigned copied,
 287			   struct page *page, void *fsdata)
 288{
 289	struct inode *inode = mapping->host;
 290	unsigned int start = pos & (PAGE_SIZE - 1);
 291	unsigned int nr_dirty;
 292	int err;
 293
 294	nr_dirty = nilfs_page_count_clean_buffers(page, start,
 295						  start + copied);
 296	copied = generic_write_end(file, mapping, pos, len, copied, page,
 297				   fsdata);
 298	nilfs_set_file_dirty(inode, nr_dirty);
 299	err = nilfs_transaction_commit(inode->i_sb);
 300	return err ? : copied;
 301}
 302
 303static ssize_t
 304nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 305{
 306	struct inode *inode = file_inode(iocb->ki_filp);
 307
 308	if (iov_iter_rw(iter) == WRITE)
 309		return 0;
 310
 311	/* Needs synchronization with the cleaner */
 312	return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 313}
 314
 315const struct address_space_operations nilfs_aops = {
 316	.writepage		= nilfs_writepage,
 317	.readpage		= nilfs_readpage,
 318	.writepages		= nilfs_writepages,
 319	.set_page_dirty		= nilfs_set_page_dirty,
 320	.readpages		= nilfs_readpages,
 321	.write_begin		= nilfs_write_begin,
 322	.write_end		= nilfs_write_end,
 323	/* .releasepage		= nilfs_releasepage, */
 324	.invalidatepage		= block_invalidatepage,
 325	.direct_IO		= nilfs_direct_IO,
 326	.is_partially_uptodate  = block_is_partially_uptodate,
 327};
 328
 329static int nilfs_insert_inode_locked(struct inode *inode,
 330				     struct nilfs_root *root,
 331				     unsigned long ino)
 332{
 333	struct nilfs_iget_args args = {
 334		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 335	};
 336
 337	return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 338}
 339
 340struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 341{
 342	struct super_block *sb = dir->i_sb;
 343	struct the_nilfs *nilfs = sb->s_fs_info;
 344	struct inode *inode;
 345	struct nilfs_inode_info *ii;
 346	struct nilfs_root *root;
 347	int err = -ENOMEM;
 348	ino_t ino;
 349
 350	inode = new_inode(sb);
 351	if (unlikely(!inode))
 352		goto failed;
 353
 354	mapping_set_gfp_mask(inode->i_mapping,
 355			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 356
 357	root = NILFS_I(dir)->i_root;
 358	ii = NILFS_I(inode);
 359	ii->i_state = BIT(NILFS_I_NEW);
 360	ii->i_root = root;
 361
 362	err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 363	if (unlikely(err))
 364		goto failed_ifile_create_inode;
 365	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
 366
 367	atomic64_inc(&root->inodes_count);
 368	inode_init_owner(inode, dir, mode);
 369	inode->i_ino = ino;
 370	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 371
 372	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 373		err = nilfs_bmap_read(ii->i_bmap, NULL);
 374		if (err < 0)
 375			goto failed_after_creation;
 376
 377		set_bit(NILFS_I_BMAP, &ii->i_state);
 378		/* No lock is needed; iget() ensures it. */
 379	}
 380
 381	ii->i_flags = nilfs_mask_flags(
 382		mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 383
 384	/* ii->i_file_acl = 0; */
 385	/* ii->i_dir_acl = 0; */
 386	ii->i_dir_start_lookup = 0;
 387	nilfs_set_inode_flags(inode);
 388	spin_lock(&nilfs->ns_next_gen_lock);
 389	inode->i_generation = nilfs->ns_next_generation++;
 390	spin_unlock(&nilfs->ns_next_gen_lock);
 391	if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 392		err = -EIO;
 393		goto failed_after_creation;
 394	}
 395
 396	err = nilfs_init_acl(inode, dir);
 397	if (unlikely(err))
 398		/*
 399		 * Never occur.  When supporting nilfs_init_acl(),
 400		 * proper cancellation of above jobs should be considered.
 401		 */
 402		goto failed_after_creation;
 403
 404	return inode;
 405
 406 failed_after_creation:
 407	clear_nlink(inode);
 408	unlock_new_inode(inode);
 409	iput(inode);  /*
 410		       * raw_inode will be deleted through
 411		       * nilfs_evict_inode().
 412		       */
 413	goto failed;
 414
 415 failed_ifile_create_inode:
 416	make_bad_inode(inode);
 417	iput(inode);
 418 failed:
 419	return ERR_PTR(err);
 420}
 421
 422void nilfs_set_inode_flags(struct inode *inode)
 423{
 424	unsigned int flags = NILFS_I(inode)->i_flags;
 425	unsigned int new_fl = 0;
 426
 427	if (flags & FS_SYNC_FL)
 428		new_fl |= S_SYNC;
 429	if (flags & FS_APPEND_FL)
 430		new_fl |= S_APPEND;
 431	if (flags & FS_IMMUTABLE_FL)
 432		new_fl |= S_IMMUTABLE;
 433	if (flags & FS_NOATIME_FL)
 434		new_fl |= S_NOATIME;
 435	if (flags & FS_DIRSYNC_FL)
 436		new_fl |= S_DIRSYNC;
 437	inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 438			S_NOATIME | S_DIRSYNC);
 439}
 440
 441int nilfs_read_inode_common(struct inode *inode,
 442			    struct nilfs_inode *raw_inode)
 443{
 444	struct nilfs_inode_info *ii = NILFS_I(inode);
 445	int err;
 446
 447	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 448	i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 449	i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 450	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 451	inode->i_size = le64_to_cpu(raw_inode->i_size);
 452	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 453	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 454	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 455	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 456	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 457	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 458	if (inode->i_nlink == 0)
 459		return -ESTALE; /* this inode is deleted */
 460
 461	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 462	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 463#if 0
 464	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 465	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 466		0 : le32_to_cpu(raw_inode->i_dir_acl);
 467#endif
 468	ii->i_dir_start_lookup = 0;
 469	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 470
 471	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 472	    S_ISLNK(inode->i_mode)) {
 473		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 474		if (err < 0)
 475			return err;
 476		set_bit(NILFS_I_BMAP, &ii->i_state);
 477		/* No lock is needed; iget() ensures it. */
 478	}
 479	return 0;
 480}
 481
 482static int __nilfs_read_inode(struct super_block *sb,
 483			      struct nilfs_root *root, unsigned long ino,
 484			      struct inode *inode)
 485{
 486	struct the_nilfs *nilfs = sb->s_fs_info;
 487	struct buffer_head *bh;
 488	struct nilfs_inode *raw_inode;
 489	int err;
 490
 491	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 492	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 493	if (unlikely(err))
 494		goto bad_inode;
 495
 496	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 497
 498	err = nilfs_read_inode_common(inode, raw_inode);
 499	if (err)
 500		goto failed_unmap;
 501
 502	if (S_ISREG(inode->i_mode)) {
 503		inode->i_op = &nilfs_file_inode_operations;
 504		inode->i_fop = &nilfs_file_operations;
 505		inode->i_mapping->a_ops = &nilfs_aops;
 506	} else if (S_ISDIR(inode->i_mode)) {
 507		inode->i_op = &nilfs_dir_inode_operations;
 508		inode->i_fop = &nilfs_dir_operations;
 509		inode->i_mapping->a_ops = &nilfs_aops;
 510	} else if (S_ISLNK(inode->i_mode)) {
 511		inode->i_op = &nilfs_symlink_inode_operations;
 512		inode_nohighmem(inode);
 513		inode->i_mapping->a_ops = &nilfs_aops;
 514	} else {
 515		inode->i_op = &nilfs_special_inode_operations;
 516		init_special_inode(
 517			inode, inode->i_mode,
 518			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 519	}
 520	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 521	brelse(bh);
 522	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 523	nilfs_set_inode_flags(inode);
 524	mapping_set_gfp_mask(inode->i_mapping,
 525			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 526	return 0;
 527
 528 failed_unmap:
 529	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 530	brelse(bh);
 531
 532 bad_inode:
 533	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 534	return err;
 535}
 536
 537static int nilfs_iget_test(struct inode *inode, void *opaque)
 538{
 539	struct nilfs_iget_args *args = opaque;
 540	struct nilfs_inode_info *ii;
 541
 542	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 543		return 0;
 544
 545	ii = NILFS_I(inode);
 546	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 547		return !args->for_gc;
 548
 549	return args->for_gc && args->cno == ii->i_cno;
 550}
 551
 552static int nilfs_iget_set(struct inode *inode, void *opaque)
 553{
 554	struct nilfs_iget_args *args = opaque;
 555
 556	inode->i_ino = args->ino;
 557	if (args->for_gc) {
 558		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 559		NILFS_I(inode)->i_cno = args->cno;
 560		NILFS_I(inode)->i_root = NULL;
 561	} else {
 562		if (args->root && args->ino == NILFS_ROOT_INO)
 563			nilfs_get_root(args->root);
 564		NILFS_I(inode)->i_root = args->root;
 565	}
 566	return 0;
 567}
 568
 569struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 570			    unsigned long ino)
 571{
 572	struct nilfs_iget_args args = {
 573		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 574	};
 575
 576	return ilookup5(sb, ino, nilfs_iget_test, &args);
 577}
 578
 579struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 580				unsigned long ino)
 581{
 582	struct nilfs_iget_args args = {
 583		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 584	};
 585
 586	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 587}
 588
 589struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 590			 unsigned long ino)
 591{
 592	struct inode *inode;
 593	int err;
 594
 595	inode = nilfs_iget_locked(sb, root, ino);
 596	if (unlikely(!inode))
 597		return ERR_PTR(-ENOMEM);
 598	if (!(inode->i_state & I_NEW))
 599		return inode;
 600
 601	err = __nilfs_read_inode(sb, root, ino, inode);
 602	if (unlikely(err)) {
 603		iget_failed(inode);
 604		return ERR_PTR(err);
 605	}
 606	unlock_new_inode(inode);
 607	return inode;
 608}
 609
 610struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 611				__u64 cno)
 612{
 613	struct nilfs_iget_args args = {
 614		.ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 615	};
 616	struct inode *inode;
 617	int err;
 618
 619	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 620	if (unlikely(!inode))
 621		return ERR_PTR(-ENOMEM);
 622	if (!(inode->i_state & I_NEW))
 623		return inode;
 624
 625	err = nilfs_init_gcinode(inode);
 626	if (unlikely(err)) {
 627		iget_failed(inode);
 628		return ERR_PTR(err);
 629	}
 630	unlock_new_inode(inode);
 631	return inode;
 632}
 633
 634void nilfs_write_inode_common(struct inode *inode,
 635			      struct nilfs_inode *raw_inode, int has_bmap)
 636{
 637	struct nilfs_inode_info *ii = NILFS_I(inode);
 638
 639	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 640	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 641	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 642	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 643	raw_inode->i_size = cpu_to_le64(inode->i_size);
 644	raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 645	raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 646	raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 647	raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 648	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 649
 650	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 651	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 652
 653	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 654		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 655
 656		/* zero-fill unused portion in the case of super root block */
 657		raw_inode->i_xattr = 0;
 658		raw_inode->i_pad = 0;
 659		memset((void *)raw_inode + sizeof(*raw_inode), 0,
 660		       nilfs->ns_inode_size - sizeof(*raw_inode));
 661	}
 662
 663	if (has_bmap)
 664		nilfs_bmap_write(ii->i_bmap, raw_inode);
 665	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 666		raw_inode->i_device_code =
 667			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 668	/*
 669	 * When extending inode, nilfs->ns_inode_size should be checked
 670	 * for substitutions of appended fields.
 671	 */
 672}
 673
 674void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 675{
 676	ino_t ino = inode->i_ino;
 677	struct nilfs_inode_info *ii = NILFS_I(inode);
 678	struct inode *ifile = ii->i_root->ifile;
 679	struct nilfs_inode *raw_inode;
 680
 681	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 682
 683	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 684		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 685	if (flags & I_DIRTY_DATASYNC)
 686		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 687
 688	nilfs_write_inode_common(inode, raw_inode, 0);
 689		/*
 690		 * XXX: call with has_bmap = 0 is a workaround to avoid
 691		 * deadlock of bmap.  This delays update of i_bmap to just
 692		 * before writing.
 693		 */
 694
 695	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 696}
 697
 698#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
 699
 700static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 701				unsigned long from)
 702{
 703	__u64 b;
 704	int ret;
 705
 706	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 707		return;
 708repeat:
 709	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 710	if (ret == -ENOENT)
 711		return;
 712	else if (ret < 0)
 713		goto failed;
 714
 715	if (b < from)
 716		return;
 717
 718	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 719	ret = nilfs_bmap_truncate(ii->i_bmap, b);
 720	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 721	if (!ret || (ret == -ENOMEM &&
 722		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 723		goto repeat;
 724
 725failed:
 726	nilfs_msg(ii->vfs_inode.i_sb, KERN_WARNING,
 727		  "error %d truncating bmap (ino=%lu)", ret,
 728		  ii->vfs_inode.i_ino);
 729}
 730
 731void nilfs_truncate(struct inode *inode)
 732{
 733	unsigned long blkoff;
 734	unsigned int blocksize;
 735	struct nilfs_transaction_info ti;
 736	struct super_block *sb = inode->i_sb;
 737	struct nilfs_inode_info *ii = NILFS_I(inode);
 738
 739	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 740		return;
 741	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 742		return;
 743
 744	blocksize = sb->s_blocksize;
 745	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 746	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 747
 748	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 749
 750	nilfs_truncate_bmap(ii, blkoff);
 751
 752	inode->i_mtime = inode->i_ctime = current_time(inode);
 753	if (IS_SYNC(inode))
 754		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 755
 756	nilfs_mark_inode_dirty(inode);
 757	nilfs_set_file_dirty(inode, 0);
 758	nilfs_transaction_commit(sb);
 759	/*
 760	 * May construct a logical segment and may fail in sync mode.
 761	 * But truncate has no return value.
 762	 */
 763}
 764
 765static void nilfs_clear_inode(struct inode *inode)
 766{
 767	struct nilfs_inode_info *ii = NILFS_I(inode);
 768
 769	/*
 770	 * Free resources allocated in nilfs_read_inode(), here.
 771	 */
 772	BUG_ON(!list_empty(&ii->i_dirty));
 773	brelse(ii->i_bh);
 774	ii->i_bh = NULL;
 775
 776	if (nilfs_is_metadata_file_inode(inode))
 777		nilfs_mdt_clear(inode);
 778
 779	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 780		nilfs_bmap_clear(ii->i_bmap);
 781
 782	nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 783
 784	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 785		nilfs_put_root(ii->i_root);
 786}
 787
 788void nilfs_evict_inode(struct inode *inode)
 789{
 790	struct nilfs_transaction_info ti;
 791	struct super_block *sb = inode->i_sb;
 792	struct nilfs_inode_info *ii = NILFS_I(inode);
 793	int ret;
 794
 795	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 796		truncate_inode_pages_final(&inode->i_data);
 797		clear_inode(inode);
 798		nilfs_clear_inode(inode);
 799		return;
 800	}
 801	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 802
 803	truncate_inode_pages_final(&inode->i_data);
 804
 805	/* TODO: some of the following operations may fail.  */
 806	nilfs_truncate_bmap(ii, 0);
 807	nilfs_mark_inode_dirty(inode);
 808	clear_inode(inode);
 809
 810	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 811	if (!ret)
 812		atomic64_dec(&ii->i_root->inodes_count);
 813
 814	nilfs_clear_inode(inode);
 815
 816	if (IS_SYNC(inode))
 817		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 818	nilfs_transaction_commit(sb);
 819	/*
 820	 * May construct a logical segment and may fail in sync mode.
 821	 * But delete_inode has no return value.
 822	 */
 823}
 824
 825int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 826{
 827	struct nilfs_transaction_info ti;
 828	struct inode *inode = d_inode(dentry);
 829	struct super_block *sb = inode->i_sb;
 830	int err;
 831
 832	err = setattr_prepare(dentry, iattr);
 833	if (err)
 834		return err;
 835
 836	err = nilfs_transaction_begin(sb, &ti, 0);
 837	if (unlikely(err))
 838		return err;
 839
 840	if ((iattr->ia_valid & ATTR_SIZE) &&
 841	    iattr->ia_size != i_size_read(inode)) {
 842		inode_dio_wait(inode);
 843		truncate_setsize(inode, iattr->ia_size);
 844		nilfs_truncate(inode);
 845	}
 846
 847	setattr_copy(inode, iattr);
 848	mark_inode_dirty(inode);
 849
 850	if (iattr->ia_valid & ATTR_MODE) {
 851		err = nilfs_acl_chmod(inode);
 852		if (unlikely(err))
 853			goto out_err;
 854	}
 855
 856	return nilfs_transaction_commit(sb);
 857
 858out_err:
 859	nilfs_transaction_abort(sb);
 860	return err;
 861}
 862
 863int nilfs_permission(struct inode *inode, int mask)
 864{
 865	struct nilfs_root *root = NILFS_I(inode)->i_root;
 866
 867	if ((mask & MAY_WRITE) && root &&
 868	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 869		return -EROFS; /* snapshot is not writable */
 870
 871	return generic_permission(inode, mask);
 872}
 873
 874int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 875{
 876	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 877	struct nilfs_inode_info *ii = NILFS_I(inode);
 878	int err;
 879
 880	spin_lock(&nilfs->ns_inode_lock);
 881	if (ii->i_bh == NULL) {
 882		spin_unlock(&nilfs->ns_inode_lock);
 883		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 884						  inode->i_ino, pbh);
 885		if (unlikely(err))
 886			return err;
 887		spin_lock(&nilfs->ns_inode_lock);
 888		if (ii->i_bh == NULL)
 889			ii->i_bh = *pbh;
 890		else {
 891			brelse(*pbh);
 892			*pbh = ii->i_bh;
 893		}
 894	} else
 895		*pbh = ii->i_bh;
 896
 897	get_bh(*pbh);
 898	spin_unlock(&nilfs->ns_inode_lock);
 899	return 0;
 900}
 901
 902int nilfs_inode_dirty(struct inode *inode)
 903{
 904	struct nilfs_inode_info *ii = NILFS_I(inode);
 905	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 906	int ret = 0;
 907
 908	if (!list_empty(&ii->i_dirty)) {
 909		spin_lock(&nilfs->ns_inode_lock);
 910		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 911			test_bit(NILFS_I_BUSY, &ii->i_state);
 912		spin_unlock(&nilfs->ns_inode_lock);
 913	}
 914	return ret;
 915}
 916
 917int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
 918{
 919	struct nilfs_inode_info *ii = NILFS_I(inode);
 920	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 921
 922	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 923
 924	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 925		return 0;
 926
 927	spin_lock(&nilfs->ns_inode_lock);
 928	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 929	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 930		/*
 931		 * Because this routine may race with nilfs_dispose_list(),
 932		 * we have to check NILFS_I_QUEUED here, too.
 933		 */
 934		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 935			/*
 936			 * This will happen when somebody is freeing
 937			 * this inode.
 938			 */
 939			nilfs_msg(inode->i_sb, KERN_WARNING,
 940				  "cannot set file dirty (ino=%lu): the file is being freed",
 941				  inode->i_ino);
 942			spin_unlock(&nilfs->ns_inode_lock);
 943			return -EINVAL; /*
 944					 * NILFS_I_DIRTY may remain for
 945					 * freeing inode.
 946					 */
 947		}
 948		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 949		set_bit(NILFS_I_QUEUED, &ii->i_state);
 950	}
 951	spin_unlock(&nilfs->ns_inode_lock);
 952	return 0;
 953}
 954
 955int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
 956{
 957	struct buffer_head *ibh;
 958	int err;
 959
 960	err = nilfs_load_inode_block(inode, &ibh);
 961	if (unlikely(err)) {
 962		nilfs_msg(inode->i_sb, KERN_WARNING,
 963			  "cannot mark inode dirty (ino=%lu): error %d loading inode block",
 964			  inode->i_ino, err);
 965		return err;
 966	}
 967	nilfs_update_inode(inode, ibh, flags);
 968	mark_buffer_dirty(ibh);
 969	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 970	brelse(ibh);
 971	return 0;
 972}
 973
 974/**
 975 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 976 * @inode: inode of the file to be registered.
 977 *
 978 * nilfs_dirty_inode() loads a inode block containing the specified
 979 * @inode and copies data from a nilfs_inode to a corresponding inode
 980 * entry in the inode block. This operation is excluded from the segment
 981 * construction. This function can be called both as a single operation
 982 * and as a part of indivisible file operations.
 983 */
 984void nilfs_dirty_inode(struct inode *inode, int flags)
 985{
 986	struct nilfs_transaction_info ti;
 987	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 988
 989	if (is_bad_inode(inode)) {
 990		nilfs_msg(inode->i_sb, KERN_WARNING,
 991			  "tried to mark bad_inode dirty. ignored.");
 992		dump_stack();
 993		return;
 994	}
 995	if (mdi) {
 996		nilfs_mdt_mark_dirty(inode);
 997		return;
 998	}
 999	nilfs_transaction_begin(inode->i_sb, &ti, 0);
1000	__nilfs_mark_inode_dirty(inode, flags);
1001	nilfs_transaction_commit(inode->i_sb); /* never fails */
1002}
1003
1004int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1005		 __u64 start, __u64 len)
1006{
1007	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1008	__u64 logical = 0, phys = 0, size = 0;
1009	__u32 flags = 0;
1010	loff_t isize;
1011	sector_t blkoff, end_blkoff;
1012	sector_t delalloc_blkoff;
1013	unsigned long delalloc_blklen;
1014	unsigned int blkbits = inode->i_blkbits;
1015	int ret, n;
1016
1017	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1018	if (ret)
1019		return ret;
1020
1021	inode_lock(inode);
1022
1023	isize = i_size_read(inode);
1024
1025	blkoff = start >> blkbits;
1026	end_blkoff = (start + len - 1) >> blkbits;
1027
1028	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1029							&delalloc_blkoff);
1030
1031	do {
1032		__u64 blkphy;
1033		unsigned int maxblocks;
1034
1035		if (delalloc_blklen && blkoff == delalloc_blkoff) {
1036			if (size) {
1037				/* End of the current extent */
1038				ret = fiemap_fill_next_extent(
1039					fieinfo, logical, phys, size, flags);
1040				if (ret)
1041					break;
1042			}
1043			if (blkoff > end_blkoff)
1044				break;
1045
1046			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1047			logical = blkoff << blkbits;
1048			phys = 0;
1049			size = delalloc_blklen << blkbits;
1050
1051			blkoff = delalloc_blkoff + delalloc_blklen;
1052			delalloc_blklen = nilfs_find_uncommitted_extent(
1053				inode, blkoff, &delalloc_blkoff);
1054			continue;
1055		}
1056
1057		/*
1058		 * Limit the number of blocks that we look up so as
1059		 * not to get into the next delayed allocation extent.
1060		 */
1061		maxblocks = INT_MAX;
1062		if (delalloc_blklen)
1063			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1064					  maxblocks);
1065		blkphy = 0;
1066
1067		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1068		n = nilfs_bmap_lookup_contig(
1069			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1070		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1071
1072		if (n < 0) {
1073			int past_eof;
1074
1075			if (unlikely(n != -ENOENT))
1076				break; /* error */
1077
1078			/* HOLE */
1079			blkoff++;
1080			past_eof = ((blkoff << blkbits) >= isize);
1081
1082			if (size) {
1083				/* End of the current extent */
1084
1085				if (past_eof)
1086					flags |= FIEMAP_EXTENT_LAST;
1087
1088				ret = fiemap_fill_next_extent(
1089					fieinfo, logical, phys, size, flags);
1090				if (ret)
1091					break;
1092				size = 0;
1093			}
1094			if (blkoff > end_blkoff || past_eof)
1095				break;
1096		} else {
1097			if (size) {
1098				if (phys && blkphy << blkbits == phys + size) {
1099					/* The current extent goes on */
1100					size += n << blkbits;
1101				} else {
1102					/* Terminate the current extent */
1103					ret = fiemap_fill_next_extent(
1104						fieinfo, logical, phys, size,
1105						flags);
1106					if (ret || blkoff > end_blkoff)
1107						break;
1108
1109					/* Start another extent */
1110					flags = FIEMAP_EXTENT_MERGED;
1111					logical = blkoff << blkbits;
1112					phys = blkphy << blkbits;
1113					size = n << blkbits;
1114				}
1115			} else {
1116				/* Start a new extent */
1117				flags = FIEMAP_EXTENT_MERGED;
1118				logical = blkoff << blkbits;
1119				phys = blkphy << blkbits;
1120				size = n << blkbits;
1121			}
1122			blkoff += n;
1123		}
1124		cond_resched();
1125	} while (true);
1126
1127	/* If ret is 1 then we just hit the end of the extent array */
1128	if (ret == 1)
1129		ret = 0;
1130
1131	inode_unlock(inode);
1132	return ret;
1133}
v5.4
   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * inode.c - NILFS inode operations.
   4 *
   5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 
 
 
 
 
 
 
 
 
 
   6 *
   7 * Written by Ryusuke Konishi.
   8 *
   9 */
  10
  11#include <linux/buffer_head.h>
  12#include <linux/gfp.h>
  13#include <linux/mpage.h>
  14#include <linux/pagemap.h>
  15#include <linux/writeback.h>
  16#include <linux/uio.h>
  17#include "nilfs.h"
  18#include "btnode.h"
  19#include "segment.h"
  20#include "page.h"
  21#include "mdt.h"
  22#include "cpfile.h"
  23#include "ifile.h"
  24
  25/**
  26 * struct nilfs_iget_args - arguments used during comparison between inodes
  27 * @ino: inode number
  28 * @cno: checkpoint number
  29 * @root: pointer on NILFS root object (mounted checkpoint)
  30 * @for_gc: inode for GC flag
  31 */
  32struct nilfs_iget_args {
  33	u64 ino;
  34	__u64 cno;
  35	struct nilfs_root *root;
  36	int for_gc;
  37};
  38
  39static int nilfs_iget_test(struct inode *inode, void *opaque);
  40
  41void nilfs_inode_add_blocks(struct inode *inode, int n)
  42{
  43	struct nilfs_root *root = NILFS_I(inode)->i_root;
  44
  45	inode_add_bytes(inode, i_blocksize(inode) * n);
  46	if (root)
  47		atomic64_add(n, &root->blocks_count);
  48}
  49
  50void nilfs_inode_sub_blocks(struct inode *inode, int n)
  51{
  52	struct nilfs_root *root = NILFS_I(inode)->i_root;
  53
  54	inode_sub_bytes(inode, i_blocksize(inode) * n);
  55	if (root)
  56		atomic64_sub(n, &root->blocks_count);
  57}
  58
  59/**
  60 * nilfs_get_block() - get a file block on the filesystem (callback function)
  61 * @inode - inode struct of the target file
  62 * @blkoff - file block number
  63 * @bh_result - buffer head to be mapped on
  64 * @create - indicate whether allocating the block or not when it has not
  65 *      been allocated yet.
  66 *
  67 * This function does not issue actual read request of the specified data
  68 * block. It is done by VFS.
  69 */
  70int nilfs_get_block(struct inode *inode, sector_t blkoff,
  71		    struct buffer_head *bh_result, int create)
  72{
  73	struct nilfs_inode_info *ii = NILFS_I(inode);
  74	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  75	__u64 blknum = 0;
  76	int err = 0, ret;
  77	unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  78
  79	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  80	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  81	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  82	if (ret >= 0) {	/* found */
  83		map_bh(bh_result, inode->i_sb, blknum);
  84		if (ret > 0)
  85			bh_result->b_size = (ret << inode->i_blkbits);
  86		goto out;
  87	}
  88	/* data block was not found */
  89	if (ret == -ENOENT && create) {
  90		struct nilfs_transaction_info ti;
  91
  92		bh_result->b_blocknr = 0;
  93		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
  94		if (unlikely(err))
  95			goto out;
  96		err = nilfs_bmap_insert(ii->i_bmap, blkoff,
  97					(unsigned long)bh_result);
  98		if (unlikely(err != 0)) {
  99			if (err == -EEXIST) {
 100				/*
 101				 * The get_block() function could be called
 102				 * from multiple callers for an inode.
 103				 * However, the page having this block must
 104				 * be locked in this case.
 105				 */
 106				nilfs_msg(inode->i_sb, KERN_WARNING,
 107					  "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 108					  __func__, inode->i_ino,
 109					  (unsigned long long)blkoff);
 110				err = 0;
 111			}
 112			nilfs_transaction_abort(inode->i_sb);
 113			goto out;
 114		}
 115		nilfs_mark_inode_dirty_sync(inode);
 116		nilfs_transaction_commit(inode->i_sb); /* never fails */
 117		/* Error handling should be detailed */
 118		set_buffer_new(bh_result);
 119		set_buffer_delay(bh_result);
 120		map_bh(bh_result, inode->i_sb, 0);
 121		/* Disk block number must be changed to proper value */
 122
 123	} else if (ret == -ENOENT) {
 124		/*
 125		 * not found is not error (e.g. hole); must return without
 126		 * the mapped state flag.
 127		 */
 128		;
 129	} else {
 130		err = ret;
 131	}
 132
 133 out:
 134	return err;
 135}
 136
 137/**
 138 * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 139 * address_space_operations.
 140 * @file - file struct of the file to be read
 141 * @page - the page to be read
 142 */
 143static int nilfs_readpage(struct file *file, struct page *page)
 144{
 145	return mpage_readpage(page, nilfs_get_block);
 146}
 147
 148/**
 149 * nilfs_readpages() - implement readpages() method of nilfs_aops {}
 150 * address_space_operations.
 151 * @file - file struct of the file to be read
 152 * @mapping - address_space struct used for reading multiple pages
 153 * @pages - the pages to be read
 154 * @nr_pages - number of pages to be read
 155 */
 156static int nilfs_readpages(struct file *file, struct address_space *mapping,
 157			   struct list_head *pages, unsigned int nr_pages)
 158{
 159	return mpage_readpages(mapping, pages, nr_pages, nilfs_get_block);
 160}
 161
 162static int nilfs_writepages(struct address_space *mapping,
 163			    struct writeback_control *wbc)
 164{
 165	struct inode *inode = mapping->host;
 166	int err = 0;
 167
 168	if (sb_rdonly(inode->i_sb)) {
 169		nilfs_clear_dirty_pages(mapping, false);
 170		return -EROFS;
 171	}
 172
 173	if (wbc->sync_mode == WB_SYNC_ALL)
 174		err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 175						    wbc->range_start,
 176						    wbc->range_end);
 177	return err;
 178}
 179
 180static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 181{
 182	struct inode *inode = page->mapping->host;
 183	int err;
 184
 185	if (sb_rdonly(inode->i_sb)) {
 186		/*
 187		 * It means that filesystem was remounted in read-only
 188		 * mode because of error or metadata corruption. But we
 189		 * have dirty pages that try to be flushed in background.
 190		 * So, here we simply discard this dirty page.
 191		 */
 192		nilfs_clear_dirty_page(page, false);
 193		unlock_page(page);
 194		return -EROFS;
 195	}
 196
 197	redirty_page_for_writepage(wbc, page);
 198	unlock_page(page);
 199
 200	if (wbc->sync_mode == WB_SYNC_ALL) {
 201		err = nilfs_construct_segment(inode->i_sb);
 202		if (unlikely(err))
 203			return err;
 204	} else if (wbc->for_reclaim)
 205		nilfs_flush_segment(inode->i_sb, inode->i_ino);
 206
 207	return 0;
 208}
 209
 210static int nilfs_set_page_dirty(struct page *page)
 211{
 212	struct inode *inode = page->mapping->host;
 213	int ret = __set_page_dirty_nobuffers(page);
 214
 215	if (page_has_buffers(page)) {
 216		unsigned int nr_dirty = 0;
 217		struct buffer_head *bh, *head;
 218
 219		/*
 220		 * This page is locked by callers, and no other thread
 221		 * concurrently marks its buffers dirty since they are
 222		 * only dirtied through routines in fs/buffer.c in
 223		 * which call sites of mark_buffer_dirty are protected
 224		 * by page lock.
 225		 */
 226		bh = head = page_buffers(page);
 227		do {
 228			/* Do not mark hole blocks dirty */
 229			if (buffer_dirty(bh) || !buffer_mapped(bh))
 230				continue;
 231
 232			set_buffer_dirty(bh);
 233			nr_dirty++;
 234		} while (bh = bh->b_this_page, bh != head);
 235
 236		if (nr_dirty)
 237			nilfs_set_file_dirty(inode, nr_dirty);
 238	} else if (ret) {
 239		unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 240
 241		nilfs_set_file_dirty(inode, nr_dirty);
 242	}
 243	return ret;
 244}
 245
 246void nilfs_write_failed(struct address_space *mapping, loff_t to)
 247{
 248	struct inode *inode = mapping->host;
 249
 250	if (to > inode->i_size) {
 251		truncate_pagecache(inode, inode->i_size);
 252		nilfs_truncate(inode);
 253	}
 254}
 255
 256static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 257			     loff_t pos, unsigned len, unsigned flags,
 258			     struct page **pagep, void **fsdata)
 259
 260{
 261	struct inode *inode = mapping->host;
 262	int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 263
 264	if (unlikely(err))
 265		return err;
 266
 267	err = block_write_begin(mapping, pos, len, flags, pagep,
 268				nilfs_get_block);
 269	if (unlikely(err)) {
 270		nilfs_write_failed(mapping, pos + len);
 271		nilfs_transaction_abort(inode->i_sb);
 272	}
 273	return err;
 274}
 275
 276static int nilfs_write_end(struct file *file, struct address_space *mapping,
 277			   loff_t pos, unsigned len, unsigned copied,
 278			   struct page *page, void *fsdata)
 279{
 280	struct inode *inode = mapping->host;
 281	unsigned int start = pos & (PAGE_SIZE - 1);
 282	unsigned int nr_dirty;
 283	int err;
 284
 285	nr_dirty = nilfs_page_count_clean_buffers(page, start,
 286						  start + copied);
 287	copied = generic_write_end(file, mapping, pos, len, copied, page,
 288				   fsdata);
 289	nilfs_set_file_dirty(inode, nr_dirty);
 290	err = nilfs_transaction_commit(inode->i_sb);
 291	return err ? : copied;
 292}
 293
 294static ssize_t
 295nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 296{
 297	struct inode *inode = file_inode(iocb->ki_filp);
 298
 299	if (iov_iter_rw(iter) == WRITE)
 300		return 0;
 301
 302	/* Needs synchronization with the cleaner */
 303	return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 304}
 305
 306const struct address_space_operations nilfs_aops = {
 307	.writepage		= nilfs_writepage,
 308	.readpage		= nilfs_readpage,
 309	.writepages		= nilfs_writepages,
 310	.set_page_dirty		= nilfs_set_page_dirty,
 311	.readpages		= nilfs_readpages,
 312	.write_begin		= nilfs_write_begin,
 313	.write_end		= nilfs_write_end,
 314	/* .releasepage		= nilfs_releasepage, */
 315	.invalidatepage		= block_invalidatepage,
 316	.direct_IO		= nilfs_direct_IO,
 317	.is_partially_uptodate  = block_is_partially_uptodate,
 318};
 319
 320static int nilfs_insert_inode_locked(struct inode *inode,
 321				     struct nilfs_root *root,
 322				     unsigned long ino)
 323{
 324	struct nilfs_iget_args args = {
 325		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 326	};
 327
 328	return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 329}
 330
 331struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 332{
 333	struct super_block *sb = dir->i_sb;
 334	struct the_nilfs *nilfs = sb->s_fs_info;
 335	struct inode *inode;
 336	struct nilfs_inode_info *ii;
 337	struct nilfs_root *root;
 338	int err = -ENOMEM;
 339	ino_t ino;
 340
 341	inode = new_inode(sb);
 342	if (unlikely(!inode))
 343		goto failed;
 344
 345	mapping_set_gfp_mask(inode->i_mapping,
 346			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 347
 348	root = NILFS_I(dir)->i_root;
 349	ii = NILFS_I(inode);
 350	ii->i_state = BIT(NILFS_I_NEW);
 351	ii->i_root = root;
 352
 353	err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 354	if (unlikely(err))
 355		goto failed_ifile_create_inode;
 356	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
 357
 358	atomic64_inc(&root->inodes_count);
 359	inode_init_owner(inode, dir, mode);
 360	inode->i_ino = ino;
 361	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 362
 363	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 364		err = nilfs_bmap_read(ii->i_bmap, NULL);
 365		if (err < 0)
 366			goto failed_after_creation;
 367
 368		set_bit(NILFS_I_BMAP, &ii->i_state);
 369		/* No lock is needed; iget() ensures it. */
 370	}
 371
 372	ii->i_flags = nilfs_mask_flags(
 373		mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 374
 375	/* ii->i_file_acl = 0; */
 376	/* ii->i_dir_acl = 0; */
 377	ii->i_dir_start_lookup = 0;
 378	nilfs_set_inode_flags(inode);
 379	spin_lock(&nilfs->ns_next_gen_lock);
 380	inode->i_generation = nilfs->ns_next_generation++;
 381	spin_unlock(&nilfs->ns_next_gen_lock);
 382	if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 383		err = -EIO;
 384		goto failed_after_creation;
 385	}
 386
 387	err = nilfs_init_acl(inode, dir);
 388	if (unlikely(err))
 389		/*
 390		 * Never occur.  When supporting nilfs_init_acl(),
 391		 * proper cancellation of above jobs should be considered.
 392		 */
 393		goto failed_after_creation;
 394
 395	return inode;
 396
 397 failed_after_creation:
 398	clear_nlink(inode);
 399	unlock_new_inode(inode);
 400	iput(inode);  /*
 401		       * raw_inode will be deleted through
 402		       * nilfs_evict_inode().
 403		       */
 404	goto failed;
 405
 406 failed_ifile_create_inode:
 407	make_bad_inode(inode);
 408	iput(inode);
 409 failed:
 410	return ERR_PTR(err);
 411}
 412
 413void nilfs_set_inode_flags(struct inode *inode)
 414{
 415	unsigned int flags = NILFS_I(inode)->i_flags;
 416	unsigned int new_fl = 0;
 417
 418	if (flags & FS_SYNC_FL)
 419		new_fl |= S_SYNC;
 420	if (flags & FS_APPEND_FL)
 421		new_fl |= S_APPEND;
 422	if (flags & FS_IMMUTABLE_FL)
 423		new_fl |= S_IMMUTABLE;
 424	if (flags & FS_NOATIME_FL)
 425		new_fl |= S_NOATIME;
 426	if (flags & FS_DIRSYNC_FL)
 427		new_fl |= S_DIRSYNC;
 428	inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 429			S_NOATIME | S_DIRSYNC);
 430}
 431
 432int nilfs_read_inode_common(struct inode *inode,
 433			    struct nilfs_inode *raw_inode)
 434{
 435	struct nilfs_inode_info *ii = NILFS_I(inode);
 436	int err;
 437
 438	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 439	i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 440	i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 441	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 442	inode->i_size = le64_to_cpu(raw_inode->i_size);
 443	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 444	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 445	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 446	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 447	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 448	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 449	if (inode->i_nlink == 0)
 450		return -ESTALE; /* this inode is deleted */
 451
 452	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 453	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 454#if 0
 455	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 456	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 457		0 : le32_to_cpu(raw_inode->i_dir_acl);
 458#endif
 459	ii->i_dir_start_lookup = 0;
 460	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 461
 462	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 463	    S_ISLNK(inode->i_mode)) {
 464		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 465		if (err < 0)
 466			return err;
 467		set_bit(NILFS_I_BMAP, &ii->i_state);
 468		/* No lock is needed; iget() ensures it. */
 469	}
 470	return 0;
 471}
 472
 473static int __nilfs_read_inode(struct super_block *sb,
 474			      struct nilfs_root *root, unsigned long ino,
 475			      struct inode *inode)
 476{
 477	struct the_nilfs *nilfs = sb->s_fs_info;
 478	struct buffer_head *bh;
 479	struct nilfs_inode *raw_inode;
 480	int err;
 481
 482	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 483	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 484	if (unlikely(err))
 485		goto bad_inode;
 486
 487	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 488
 489	err = nilfs_read_inode_common(inode, raw_inode);
 490	if (err)
 491		goto failed_unmap;
 492
 493	if (S_ISREG(inode->i_mode)) {
 494		inode->i_op = &nilfs_file_inode_operations;
 495		inode->i_fop = &nilfs_file_operations;
 496		inode->i_mapping->a_ops = &nilfs_aops;
 497	} else if (S_ISDIR(inode->i_mode)) {
 498		inode->i_op = &nilfs_dir_inode_operations;
 499		inode->i_fop = &nilfs_dir_operations;
 500		inode->i_mapping->a_ops = &nilfs_aops;
 501	} else if (S_ISLNK(inode->i_mode)) {
 502		inode->i_op = &nilfs_symlink_inode_operations;
 503		inode_nohighmem(inode);
 504		inode->i_mapping->a_ops = &nilfs_aops;
 505	} else {
 506		inode->i_op = &nilfs_special_inode_operations;
 507		init_special_inode(
 508			inode, inode->i_mode,
 509			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 510	}
 511	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 512	brelse(bh);
 513	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 514	nilfs_set_inode_flags(inode);
 515	mapping_set_gfp_mask(inode->i_mapping,
 516			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 517	return 0;
 518
 519 failed_unmap:
 520	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 521	brelse(bh);
 522
 523 bad_inode:
 524	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 525	return err;
 526}
 527
 528static int nilfs_iget_test(struct inode *inode, void *opaque)
 529{
 530	struct nilfs_iget_args *args = opaque;
 531	struct nilfs_inode_info *ii;
 532
 533	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 534		return 0;
 535
 536	ii = NILFS_I(inode);
 537	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 538		return !args->for_gc;
 539
 540	return args->for_gc && args->cno == ii->i_cno;
 541}
 542
 543static int nilfs_iget_set(struct inode *inode, void *opaque)
 544{
 545	struct nilfs_iget_args *args = opaque;
 546
 547	inode->i_ino = args->ino;
 548	if (args->for_gc) {
 549		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 550		NILFS_I(inode)->i_cno = args->cno;
 551		NILFS_I(inode)->i_root = NULL;
 552	} else {
 553		if (args->root && args->ino == NILFS_ROOT_INO)
 554			nilfs_get_root(args->root);
 555		NILFS_I(inode)->i_root = args->root;
 556	}
 557	return 0;
 558}
 559
 560struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 561			    unsigned long ino)
 562{
 563	struct nilfs_iget_args args = {
 564		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 565	};
 566
 567	return ilookup5(sb, ino, nilfs_iget_test, &args);
 568}
 569
 570struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 571				unsigned long ino)
 572{
 573	struct nilfs_iget_args args = {
 574		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 575	};
 576
 577	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 578}
 579
 580struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 581			 unsigned long ino)
 582{
 583	struct inode *inode;
 584	int err;
 585
 586	inode = nilfs_iget_locked(sb, root, ino);
 587	if (unlikely(!inode))
 588		return ERR_PTR(-ENOMEM);
 589	if (!(inode->i_state & I_NEW))
 590		return inode;
 591
 592	err = __nilfs_read_inode(sb, root, ino, inode);
 593	if (unlikely(err)) {
 594		iget_failed(inode);
 595		return ERR_PTR(err);
 596	}
 597	unlock_new_inode(inode);
 598	return inode;
 599}
 600
 601struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 602				__u64 cno)
 603{
 604	struct nilfs_iget_args args = {
 605		.ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 606	};
 607	struct inode *inode;
 608	int err;
 609
 610	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 611	if (unlikely(!inode))
 612		return ERR_PTR(-ENOMEM);
 613	if (!(inode->i_state & I_NEW))
 614		return inode;
 615
 616	err = nilfs_init_gcinode(inode);
 617	if (unlikely(err)) {
 618		iget_failed(inode);
 619		return ERR_PTR(err);
 620	}
 621	unlock_new_inode(inode);
 622	return inode;
 623}
 624
 625void nilfs_write_inode_common(struct inode *inode,
 626			      struct nilfs_inode *raw_inode, int has_bmap)
 627{
 628	struct nilfs_inode_info *ii = NILFS_I(inode);
 629
 630	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 631	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 632	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 633	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 634	raw_inode->i_size = cpu_to_le64(inode->i_size);
 635	raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 636	raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 637	raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 638	raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 639	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 640
 641	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 642	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 643
 644	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 645		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 646
 647		/* zero-fill unused portion in the case of super root block */
 648		raw_inode->i_xattr = 0;
 649		raw_inode->i_pad = 0;
 650		memset((void *)raw_inode + sizeof(*raw_inode), 0,
 651		       nilfs->ns_inode_size - sizeof(*raw_inode));
 652	}
 653
 654	if (has_bmap)
 655		nilfs_bmap_write(ii->i_bmap, raw_inode);
 656	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 657		raw_inode->i_device_code =
 658			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 659	/*
 660	 * When extending inode, nilfs->ns_inode_size should be checked
 661	 * for substitutions of appended fields.
 662	 */
 663}
 664
 665void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 666{
 667	ino_t ino = inode->i_ino;
 668	struct nilfs_inode_info *ii = NILFS_I(inode);
 669	struct inode *ifile = ii->i_root->ifile;
 670	struct nilfs_inode *raw_inode;
 671
 672	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 673
 674	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 675		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 676	if (flags & I_DIRTY_DATASYNC)
 677		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 678
 679	nilfs_write_inode_common(inode, raw_inode, 0);
 680		/*
 681		 * XXX: call with has_bmap = 0 is a workaround to avoid
 682		 * deadlock of bmap.  This delays update of i_bmap to just
 683		 * before writing.
 684		 */
 685
 686	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 687}
 688
 689#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
 690
 691static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 692				unsigned long from)
 693{
 694	__u64 b;
 695	int ret;
 696
 697	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 698		return;
 699repeat:
 700	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 701	if (ret == -ENOENT)
 702		return;
 703	else if (ret < 0)
 704		goto failed;
 705
 706	if (b < from)
 707		return;
 708
 709	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 710	ret = nilfs_bmap_truncate(ii->i_bmap, b);
 711	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 712	if (!ret || (ret == -ENOMEM &&
 713		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 714		goto repeat;
 715
 716failed:
 717	nilfs_msg(ii->vfs_inode.i_sb, KERN_WARNING,
 718		  "error %d truncating bmap (ino=%lu)", ret,
 719		  ii->vfs_inode.i_ino);
 720}
 721
 722void nilfs_truncate(struct inode *inode)
 723{
 724	unsigned long blkoff;
 725	unsigned int blocksize;
 726	struct nilfs_transaction_info ti;
 727	struct super_block *sb = inode->i_sb;
 728	struct nilfs_inode_info *ii = NILFS_I(inode);
 729
 730	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 731		return;
 732	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 733		return;
 734
 735	blocksize = sb->s_blocksize;
 736	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 737	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 738
 739	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 740
 741	nilfs_truncate_bmap(ii, blkoff);
 742
 743	inode->i_mtime = inode->i_ctime = current_time(inode);
 744	if (IS_SYNC(inode))
 745		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 746
 747	nilfs_mark_inode_dirty(inode);
 748	nilfs_set_file_dirty(inode, 0);
 749	nilfs_transaction_commit(sb);
 750	/*
 751	 * May construct a logical segment and may fail in sync mode.
 752	 * But truncate has no return value.
 753	 */
 754}
 755
 756static void nilfs_clear_inode(struct inode *inode)
 757{
 758	struct nilfs_inode_info *ii = NILFS_I(inode);
 759
 760	/*
 761	 * Free resources allocated in nilfs_read_inode(), here.
 762	 */
 763	BUG_ON(!list_empty(&ii->i_dirty));
 764	brelse(ii->i_bh);
 765	ii->i_bh = NULL;
 766
 767	if (nilfs_is_metadata_file_inode(inode))
 768		nilfs_mdt_clear(inode);
 769
 770	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 771		nilfs_bmap_clear(ii->i_bmap);
 772
 773	nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 774
 775	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 776		nilfs_put_root(ii->i_root);
 777}
 778
 779void nilfs_evict_inode(struct inode *inode)
 780{
 781	struct nilfs_transaction_info ti;
 782	struct super_block *sb = inode->i_sb;
 783	struct nilfs_inode_info *ii = NILFS_I(inode);
 784	int ret;
 785
 786	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 787		truncate_inode_pages_final(&inode->i_data);
 788		clear_inode(inode);
 789		nilfs_clear_inode(inode);
 790		return;
 791	}
 792	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 793
 794	truncate_inode_pages_final(&inode->i_data);
 795
 796	/* TODO: some of the following operations may fail.  */
 797	nilfs_truncate_bmap(ii, 0);
 798	nilfs_mark_inode_dirty(inode);
 799	clear_inode(inode);
 800
 801	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 802	if (!ret)
 803		atomic64_dec(&ii->i_root->inodes_count);
 804
 805	nilfs_clear_inode(inode);
 806
 807	if (IS_SYNC(inode))
 808		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 809	nilfs_transaction_commit(sb);
 810	/*
 811	 * May construct a logical segment and may fail in sync mode.
 812	 * But delete_inode has no return value.
 813	 */
 814}
 815
 816int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
 817{
 818	struct nilfs_transaction_info ti;
 819	struct inode *inode = d_inode(dentry);
 820	struct super_block *sb = inode->i_sb;
 821	int err;
 822
 823	err = setattr_prepare(dentry, iattr);
 824	if (err)
 825		return err;
 826
 827	err = nilfs_transaction_begin(sb, &ti, 0);
 828	if (unlikely(err))
 829		return err;
 830
 831	if ((iattr->ia_valid & ATTR_SIZE) &&
 832	    iattr->ia_size != i_size_read(inode)) {
 833		inode_dio_wait(inode);
 834		truncate_setsize(inode, iattr->ia_size);
 835		nilfs_truncate(inode);
 836	}
 837
 838	setattr_copy(inode, iattr);
 839	mark_inode_dirty(inode);
 840
 841	if (iattr->ia_valid & ATTR_MODE) {
 842		err = nilfs_acl_chmod(inode);
 843		if (unlikely(err))
 844			goto out_err;
 845	}
 846
 847	return nilfs_transaction_commit(sb);
 848
 849out_err:
 850	nilfs_transaction_abort(sb);
 851	return err;
 852}
 853
 854int nilfs_permission(struct inode *inode, int mask)
 855{
 856	struct nilfs_root *root = NILFS_I(inode)->i_root;
 857
 858	if ((mask & MAY_WRITE) && root &&
 859	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 860		return -EROFS; /* snapshot is not writable */
 861
 862	return generic_permission(inode, mask);
 863}
 864
 865int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 866{
 867	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 868	struct nilfs_inode_info *ii = NILFS_I(inode);
 869	int err;
 870
 871	spin_lock(&nilfs->ns_inode_lock);
 872	if (ii->i_bh == NULL) {
 873		spin_unlock(&nilfs->ns_inode_lock);
 874		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 875						  inode->i_ino, pbh);
 876		if (unlikely(err))
 877			return err;
 878		spin_lock(&nilfs->ns_inode_lock);
 879		if (ii->i_bh == NULL)
 880			ii->i_bh = *pbh;
 881		else {
 882			brelse(*pbh);
 883			*pbh = ii->i_bh;
 884		}
 885	} else
 886		*pbh = ii->i_bh;
 887
 888	get_bh(*pbh);
 889	spin_unlock(&nilfs->ns_inode_lock);
 890	return 0;
 891}
 892
 893int nilfs_inode_dirty(struct inode *inode)
 894{
 895	struct nilfs_inode_info *ii = NILFS_I(inode);
 896	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 897	int ret = 0;
 898
 899	if (!list_empty(&ii->i_dirty)) {
 900		spin_lock(&nilfs->ns_inode_lock);
 901		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 902			test_bit(NILFS_I_BUSY, &ii->i_state);
 903		spin_unlock(&nilfs->ns_inode_lock);
 904	}
 905	return ret;
 906}
 907
 908int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
 909{
 910	struct nilfs_inode_info *ii = NILFS_I(inode);
 911	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 912
 913	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 914
 915	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 916		return 0;
 917
 918	spin_lock(&nilfs->ns_inode_lock);
 919	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 920	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 921		/*
 922		 * Because this routine may race with nilfs_dispose_list(),
 923		 * we have to check NILFS_I_QUEUED here, too.
 924		 */
 925		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 926			/*
 927			 * This will happen when somebody is freeing
 928			 * this inode.
 929			 */
 930			nilfs_msg(inode->i_sb, KERN_WARNING,
 931				  "cannot set file dirty (ino=%lu): the file is being freed",
 932				  inode->i_ino);
 933			spin_unlock(&nilfs->ns_inode_lock);
 934			return -EINVAL; /*
 935					 * NILFS_I_DIRTY may remain for
 936					 * freeing inode.
 937					 */
 938		}
 939		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 940		set_bit(NILFS_I_QUEUED, &ii->i_state);
 941	}
 942	spin_unlock(&nilfs->ns_inode_lock);
 943	return 0;
 944}
 945
 946int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
 947{
 948	struct buffer_head *ibh;
 949	int err;
 950
 951	err = nilfs_load_inode_block(inode, &ibh);
 952	if (unlikely(err)) {
 953		nilfs_msg(inode->i_sb, KERN_WARNING,
 954			  "cannot mark inode dirty (ino=%lu): error %d loading inode block",
 955			  inode->i_ino, err);
 956		return err;
 957	}
 958	nilfs_update_inode(inode, ibh, flags);
 959	mark_buffer_dirty(ibh);
 960	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 961	brelse(ibh);
 962	return 0;
 963}
 964
 965/**
 966 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 967 * @inode: inode of the file to be registered.
 968 *
 969 * nilfs_dirty_inode() loads a inode block containing the specified
 970 * @inode and copies data from a nilfs_inode to a corresponding inode
 971 * entry in the inode block. This operation is excluded from the segment
 972 * construction. This function can be called both as a single operation
 973 * and as a part of indivisible file operations.
 974 */
 975void nilfs_dirty_inode(struct inode *inode, int flags)
 976{
 977	struct nilfs_transaction_info ti;
 978	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 979
 980	if (is_bad_inode(inode)) {
 981		nilfs_msg(inode->i_sb, KERN_WARNING,
 982			  "tried to mark bad_inode dirty. ignored.");
 983		dump_stack();
 984		return;
 985	}
 986	if (mdi) {
 987		nilfs_mdt_mark_dirty(inode);
 988		return;
 989	}
 990	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 991	__nilfs_mark_inode_dirty(inode, flags);
 992	nilfs_transaction_commit(inode->i_sb); /* never fails */
 993}
 994
 995int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 996		 __u64 start, __u64 len)
 997{
 998	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 999	__u64 logical = 0, phys = 0, size = 0;
1000	__u32 flags = 0;
1001	loff_t isize;
1002	sector_t blkoff, end_blkoff;
1003	sector_t delalloc_blkoff;
1004	unsigned long delalloc_blklen;
1005	unsigned int blkbits = inode->i_blkbits;
1006	int ret, n;
1007
1008	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
1009	if (ret)
1010		return ret;
1011
1012	inode_lock(inode);
1013
1014	isize = i_size_read(inode);
1015
1016	blkoff = start >> blkbits;
1017	end_blkoff = (start + len - 1) >> blkbits;
1018
1019	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1020							&delalloc_blkoff);
1021
1022	do {
1023		__u64 blkphy;
1024		unsigned int maxblocks;
1025
1026		if (delalloc_blklen && blkoff == delalloc_blkoff) {
1027			if (size) {
1028				/* End of the current extent */
1029				ret = fiemap_fill_next_extent(
1030					fieinfo, logical, phys, size, flags);
1031				if (ret)
1032					break;
1033			}
1034			if (blkoff > end_blkoff)
1035				break;
1036
1037			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1038			logical = blkoff << blkbits;
1039			phys = 0;
1040			size = delalloc_blklen << blkbits;
1041
1042			blkoff = delalloc_blkoff + delalloc_blklen;
1043			delalloc_blklen = nilfs_find_uncommitted_extent(
1044				inode, blkoff, &delalloc_blkoff);
1045			continue;
1046		}
1047
1048		/*
1049		 * Limit the number of blocks that we look up so as
1050		 * not to get into the next delayed allocation extent.
1051		 */
1052		maxblocks = INT_MAX;
1053		if (delalloc_blklen)
1054			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1055					  maxblocks);
1056		blkphy = 0;
1057
1058		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1059		n = nilfs_bmap_lookup_contig(
1060			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1061		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1062
1063		if (n < 0) {
1064			int past_eof;
1065
1066			if (unlikely(n != -ENOENT))
1067				break; /* error */
1068
1069			/* HOLE */
1070			blkoff++;
1071			past_eof = ((blkoff << blkbits) >= isize);
1072
1073			if (size) {
1074				/* End of the current extent */
1075
1076				if (past_eof)
1077					flags |= FIEMAP_EXTENT_LAST;
1078
1079				ret = fiemap_fill_next_extent(
1080					fieinfo, logical, phys, size, flags);
1081				if (ret)
1082					break;
1083				size = 0;
1084			}
1085			if (blkoff > end_blkoff || past_eof)
1086				break;
1087		} else {
1088			if (size) {
1089				if (phys && blkphy << blkbits == phys + size) {
1090					/* The current extent goes on */
1091					size += n << blkbits;
1092				} else {
1093					/* Terminate the current extent */
1094					ret = fiemap_fill_next_extent(
1095						fieinfo, logical, phys, size,
1096						flags);
1097					if (ret || blkoff > end_blkoff)
1098						break;
1099
1100					/* Start another extent */
1101					flags = FIEMAP_EXTENT_MERGED;
1102					logical = blkoff << blkbits;
1103					phys = blkphy << blkbits;
1104					size = n << blkbits;
1105				}
1106			} else {
1107				/* Start a new extent */
1108				flags = FIEMAP_EXTENT_MERGED;
1109				logical = blkoff << blkbits;
1110				phys = blkphy << blkbits;
1111				size = n << blkbits;
1112			}
1113			blkoff += n;
1114		}
1115		cond_resched();
1116	} while (true);
1117
1118	/* If ret is 1 then we just hit the end of the extent array */
1119	if (ret == 1)
1120		ret = 0;
1121
1122	inode_unlock(inode);
1123	return ret;
1124}