1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * 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 <linux/fiemap.h>
  18#include "nilfs.h"
  19#include "btnode.h"
  20#include "segment.h"
  21#include "page.h"
  22#include "mdt.h"
  23#include "cpfile.h"
  24#include "ifile.h"
  25
  26/**
  27 * struct nilfs_iget_args - arguments used during comparison between inodes
  28 * @ino: inode number
  29 * @cno: checkpoint number
  30 * @root: pointer on NILFS root object (mounted checkpoint)
  31 * @for_gc: inode for GC flag
  32 * @for_btnc: inode for B-tree node cache flag
  33 * @for_shadow: inode for shadowed page cache flag
  34 */
  35struct nilfs_iget_args {
  36	u64 ino;
  37	__u64 cno;
  38	struct nilfs_root *root;
  39	bool for_gc;
  40	bool for_btnc;
  41	bool for_shadow;
  42};
  43
  44static int nilfs_iget_test(struct inode *inode, void *opaque);
  45
  46void nilfs_inode_add_blocks(struct inode *inode, int n)
  47{
  48	struct nilfs_root *root = NILFS_I(inode)->i_root;
  49
  50	inode_add_bytes(inode, i_blocksize(inode) * n);
  51	if (root)
  52		atomic64_add(n, &root->blocks_count);
  53}
  54
  55void nilfs_inode_sub_blocks(struct inode *inode, int n)
  56{
  57	struct nilfs_root *root = NILFS_I(inode)->i_root;
  58
  59	inode_sub_bytes(inode, i_blocksize(inode) * n);
  60	if (root)
  61		atomic64_sub(n, &root->blocks_count);
  62}
  63
  64/**
  65 * nilfs_get_block() - get a file block on the filesystem (callback function)
  66 * @inode: inode struct of the target file
  67 * @blkoff: file block number
  68 * @bh_result: buffer head to be mapped on
  69 * @create: indicate whether allocating the block or not when it has not
  70 *      been allocated yet.
  71 *
  72 * This function does not issue actual read request of the specified data
  73 * block. It is done by VFS.
  74 */
  75int nilfs_get_block(struct inode *inode, sector_t blkoff,
  76		    struct buffer_head *bh_result, int create)
  77{
  78	struct nilfs_inode_info *ii = NILFS_I(inode);
  79	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  80	__u64 blknum = 0;
  81	int err = 0, ret;
  82	unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  83
  84	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  85	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  86	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  87	if (ret >= 0) {	/* found */
  88		map_bh(bh_result, inode->i_sb, blknum);
  89		if (ret > 0)
  90			bh_result->b_size = (ret << inode->i_blkbits);
  91		goto out;
  92	}
  93	/* data block was not found */
  94	if (ret == -ENOENT && create) {
  95		struct nilfs_transaction_info ti;
  96
  97		bh_result->b_blocknr = 0;
  98		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
  99		if (unlikely(err))
 100			goto out;
 101		err = nilfs_bmap_insert(ii->i_bmap, blkoff,
 102					(unsigned long)bh_result);
 103		if (unlikely(err != 0)) {
 104			if (err == -EEXIST) {
 105				/*
 106				 * The get_block() function could be called
 107				 * from multiple callers for an inode.
 108				 * However, the page having this block must
 109				 * be locked in this case.
 110				 */
 111				nilfs_warn(inode->i_sb,
 112					   "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 113					   __func__, inode->i_ino,
 114					   (unsigned long long)blkoff);
 115				err = 0;
 116			}
 117			nilfs_transaction_abort(inode->i_sb);
 118			goto out;
 119		}
 120		nilfs_mark_inode_dirty_sync(inode);
 121		nilfs_transaction_commit(inode->i_sb); /* never fails */
 122		/* Error handling should be detailed */
 123		set_buffer_new(bh_result);
 124		set_buffer_delay(bh_result);
 125		map_bh(bh_result, inode->i_sb, 0);
 126		/* Disk block number must be changed to proper value */
 127
 128	} else if (ret == -ENOENT) {
 129		/*
 130		 * not found is not error (e.g. hole); must return without
 131		 * the mapped state flag.
 132		 */
 133		;
 134	} else {
 135		err = ret;
 136	}
 137
 138 out:
 139	return err;
 140}
 141
 142/**
 143 * nilfs_read_folio() - implement read_folio() method of nilfs_aops {}
 144 * address_space_operations.
 145 * @file: file struct of the file to be read
 146 * @folio: the folio to be read
 147 */
 148static int nilfs_read_folio(struct file *file, struct folio *folio)
 149{
 150	return mpage_read_folio(folio, nilfs_get_block);
 151}
 152
 153static void nilfs_readahead(struct readahead_control *rac)
 154{
 155	mpage_readahead(rac, nilfs_get_block);
 156}
 157
 158static int nilfs_writepages(struct address_space *mapping,
 159			    struct writeback_control *wbc)
 160{
 161	struct inode *inode = mapping->host;
 162	int err = 0;
 163
 164	if (sb_rdonly(inode->i_sb)) {
 165		nilfs_clear_dirty_pages(mapping, false);
 166		return -EROFS;
 167	}
 168
 169	if (wbc->sync_mode == WB_SYNC_ALL)
 170		err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 171						    wbc->range_start,
 172						    wbc->range_end);
 173	return err;
 174}
 175
 176static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 177{
 178	struct folio *folio = page_folio(page);
 179	struct inode *inode = folio->mapping->host;
 180	int err;
 181
 182	if (sb_rdonly(inode->i_sb)) {
 183		/*
 184		 * It means that filesystem was remounted in read-only
 185		 * mode because of error or metadata corruption. But we
 186		 * have dirty pages that try to be flushed in background.
 187		 * So, here we simply discard this dirty page.
 188		 */
 189		nilfs_clear_folio_dirty(folio, false);
 190		folio_unlock(folio);
 191		return -EROFS;
 192	}
 193
 194	folio_redirty_for_writepage(wbc, folio);
 195	folio_unlock(folio);
 196
 197	if (wbc->sync_mode == WB_SYNC_ALL) {
 198		err = nilfs_construct_segment(inode->i_sb);
 199		if (unlikely(err))
 200			return err;
 201	} else if (wbc->for_reclaim)
 202		nilfs_flush_segment(inode->i_sb, inode->i_ino);
 203
 204	return 0;
 205}
 206
 207static bool nilfs_dirty_folio(struct address_space *mapping,
 208		struct folio *folio)
 209{
 210	struct inode *inode = mapping->host;
 211	struct buffer_head *head;
 212	unsigned int nr_dirty = 0;
 213	bool ret = filemap_dirty_folio(mapping, folio);
 214
 215	/*
 216	 * The page may not be locked, eg if called from try_to_unmap_one()
 217	 */
 218	spin_lock(&mapping->i_private_lock);
 219	head = folio_buffers(folio);
 220	if (head) {
 221		struct buffer_head *bh = head;
 222
 223		do {
 224			/* Do not mark hole blocks dirty */
 225			if (buffer_dirty(bh) || !buffer_mapped(bh))
 226				continue;
 227
 228			set_buffer_dirty(bh);
 229			nr_dirty++;
 230		} while (bh = bh->b_this_page, bh != head);
 231	} else if (ret) {
 232		nr_dirty = 1 << (folio_shift(folio) - inode->i_blkbits);
 233	}
 234	spin_unlock(&mapping->i_private_lock);
 235
 236	if (nr_dirty)
 237		nilfs_set_file_dirty(inode, nr_dirty);
 238	return ret;
 239}
 240
 241void nilfs_write_failed(struct address_space *mapping, loff_t to)
 242{
 243	struct inode *inode = mapping->host;
 244
 245	if (to > inode->i_size) {
 246		truncate_pagecache(inode, inode->i_size);
 247		nilfs_truncate(inode);
 248	}
 249}
 250
 251static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 252			     loff_t pos, unsigned len,
 253			     struct page **pagep, void **fsdata)
 254
 255{
 256	struct inode *inode = mapping->host;
 257	int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 258
 259	if (unlikely(err))
 260		return err;
 261
 262	err = block_write_begin(mapping, pos, len, pagep, nilfs_get_block);
 263	if (unlikely(err)) {
 264		nilfs_write_failed(mapping, pos + len);
 265		nilfs_transaction_abort(inode->i_sb);
 266	}
 267	return err;
 268}
 269
 270static int nilfs_write_end(struct file *file, struct address_space *mapping,
 271			   loff_t pos, unsigned len, unsigned copied,
 272			   struct page *page, void *fsdata)
 273{
 274	struct inode *inode = mapping->host;
 275	unsigned int start = pos & (PAGE_SIZE - 1);
 276	unsigned int nr_dirty;
 277	int err;
 278
 279	nr_dirty = nilfs_page_count_clean_buffers(page, start,
 280						  start + copied);
 281	copied = generic_write_end(file, mapping, pos, len, copied, page,
 282				   fsdata);
 283	nilfs_set_file_dirty(inode, nr_dirty);
 284	err = nilfs_transaction_commit(inode->i_sb);
 285	return err ? : copied;
 286}
 287
 288static ssize_t
 289nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 290{
 291	struct inode *inode = file_inode(iocb->ki_filp);
 292
 293	if (iov_iter_rw(iter) == WRITE)
 294		return 0;
 295
 296	/* Needs synchronization with the cleaner */
 297	return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 298}
 299
 300const struct address_space_operations nilfs_aops = {
 301	.writepage		= nilfs_writepage,
 302	.read_folio		= nilfs_read_folio,
 303	.writepages		= nilfs_writepages,
 304	.dirty_folio		= nilfs_dirty_folio,
 305	.readahead		= nilfs_readahead,
 306	.write_begin		= nilfs_write_begin,
 307	.write_end		= nilfs_write_end,
 308	.invalidate_folio	= block_invalidate_folio,
 309	.direct_IO		= nilfs_direct_IO,
 310	.is_partially_uptodate  = block_is_partially_uptodate,
 311};
 312
 313static int nilfs_insert_inode_locked(struct inode *inode,
 314				     struct nilfs_root *root,
 315				     unsigned long ino)
 316{
 317	struct nilfs_iget_args args = {
 318		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 319		.for_btnc = false, .for_shadow = false
 320	};
 321
 322	return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 323}
 324
 325struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 326{
 327	struct super_block *sb = dir->i_sb;
 328	struct the_nilfs *nilfs = sb->s_fs_info;
 329	struct inode *inode;
 330	struct nilfs_inode_info *ii;
 331	struct nilfs_root *root;
 332	struct buffer_head *bh;
 333	int err = -ENOMEM;
 334	ino_t ino;
 335
 336	inode = new_inode(sb);
 337	if (unlikely(!inode))
 338		goto failed;
 339
 340	mapping_set_gfp_mask(inode->i_mapping,
 341			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 342
 343	root = NILFS_I(dir)->i_root;
 344	ii = NILFS_I(inode);
 345	ii->i_state = BIT(NILFS_I_NEW);
 346	ii->i_root = root;
 347
 348	err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 349	if (unlikely(err))
 350		goto failed_ifile_create_inode;
 351	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
 352
 353	if (unlikely(ino < NILFS_USER_INO)) {
 354		nilfs_warn(sb,
 355			   "inode bitmap is inconsistent for reserved inodes");
 356		do {
 357			brelse(bh);
 358			err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 359			if (unlikely(err))
 360				goto failed_ifile_create_inode;
 361		} while (ino < NILFS_USER_INO);
 362
 363		nilfs_info(sb, "repaired inode bitmap for reserved inodes");
 364	}
 365	ii->i_bh = bh;
 366
 367	atomic64_inc(&root->inodes_count);
 368	inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
 369	inode->i_ino = ino;
 370	simple_inode_init_ts(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	if (inode->i_state & I_NEW)
 409		unlock_new_inode(inode);
 410	iput(inode);  /*
 411		       * raw_inode will be deleted through
 412		       * nilfs_evict_inode().
 413		       */
 414	goto failed;
 415
 416 failed_ifile_create_inode:
 417	make_bad_inode(inode);
 418	iput(inode);
 419 failed:
 420	return ERR_PTR(err);
 421}
 422
 423void nilfs_set_inode_flags(struct inode *inode)
 424{
 425	unsigned int flags = NILFS_I(inode)->i_flags;
 426	unsigned int new_fl = 0;
 427
 428	if (flags & FS_SYNC_FL)
 429		new_fl |= S_SYNC;
 430	if (flags & FS_APPEND_FL)
 431		new_fl |= S_APPEND;
 432	if (flags & FS_IMMUTABLE_FL)
 433		new_fl |= S_IMMUTABLE;
 434	if (flags & FS_NOATIME_FL)
 435		new_fl |= S_NOATIME;
 436	if (flags & FS_DIRSYNC_FL)
 437		new_fl |= S_DIRSYNC;
 438	inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 439			S_NOATIME | S_DIRSYNC);
 440}
 441
 442int nilfs_read_inode_common(struct inode *inode,
 443			    struct nilfs_inode *raw_inode)
 444{
 445	struct nilfs_inode_info *ii = NILFS_I(inode);
 446	int err;
 447
 448	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 449	i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 450	i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 451	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 452	inode->i_size = le64_to_cpu(raw_inode->i_size);
 453	inode_set_atime(inode, le64_to_cpu(raw_inode->i_mtime),
 454			le32_to_cpu(raw_inode->i_mtime_nsec));
 455	inode_set_ctime(inode, le64_to_cpu(raw_inode->i_ctime),
 456			le32_to_cpu(raw_inode->i_ctime_nsec));
 457	inode_set_mtime(inode, le64_to_cpu(raw_inode->i_mtime),
 458			le32_to_cpu(raw_inode->i_mtime_nsec));
 459	if (nilfs_is_metadata_file_inode(inode) && !S_ISREG(inode->i_mode))
 460		return -EIO; /* this inode is for metadata and corrupted */
 461	if (inode->i_nlink == 0)
 462		return -ESTALE; /* this inode is deleted */
 463
 464	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 465	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 466#if 0
 467	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 468	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 469		0 : le32_to_cpu(raw_inode->i_dir_acl);
 470#endif
 471	ii->i_dir_start_lookup = 0;
 472	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 473
 474	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 475	    S_ISLNK(inode->i_mode)) {
 476		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 477		if (err < 0)
 478			return err;
 479		set_bit(NILFS_I_BMAP, &ii->i_state);
 480		/* No lock is needed; iget() ensures it. */
 481	}
 482	return 0;
 483}
 484
 485static int __nilfs_read_inode(struct super_block *sb,
 486			      struct nilfs_root *root, unsigned long ino,
 487			      struct inode *inode)
 488{
 489	struct the_nilfs *nilfs = sb->s_fs_info;
 490	struct buffer_head *bh;
 491	struct nilfs_inode *raw_inode;
 492	int err;
 493
 494	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 495	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 496	if (unlikely(err))
 497		goto bad_inode;
 498
 499	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 500
 501	err = nilfs_read_inode_common(inode, raw_inode);
 502	if (err)
 503		goto failed_unmap;
 504
 505	if (S_ISREG(inode->i_mode)) {
 506		inode->i_op = &nilfs_file_inode_operations;
 507		inode->i_fop = &nilfs_file_operations;
 508		inode->i_mapping->a_ops = &nilfs_aops;
 509	} else if (S_ISDIR(inode->i_mode)) {
 510		inode->i_op = &nilfs_dir_inode_operations;
 511		inode->i_fop = &nilfs_dir_operations;
 512		inode->i_mapping->a_ops = &nilfs_aops;
 513	} else if (S_ISLNK(inode->i_mode)) {
 514		inode->i_op = &nilfs_symlink_inode_operations;
 515		inode_nohighmem(inode);
 516		inode->i_mapping->a_ops = &nilfs_aops;
 517	} else {
 518		inode->i_op = &nilfs_special_inode_operations;
 519		init_special_inode(
 520			inode, inode->i_mode,
 521			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 522	}
 523	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 524	brelse(bh);
 525	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 526	nilfs_set_inode_flags(inode);
 527	mapping_set_gfp_mask(inode->i_mapping,
 528			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 529	return 0;
 530
 531 failed_unmap:
 532	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 533	brelse(bh);
 534
 535 bad_inode:
 536	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 537	return err;
 538}
 539
 540static int nilfs_iget_test(struct inode *inode, void *opaque)
 541{
 542	struct nilfs_iget_args *args = opaque;
 543	struct nilfs_inode_info *ii;
 544
 545	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 546		return 0;
 547
 548	ii = NILFS_I(inode);
 549	if (test_bit(NILFS_I_BTNC, &ii->i_state)) {
 550		if (!args->for_btnc)
 551			return 0;
 552	} else if (args->for_btnc) {
 553		return 0;
 554	}
 555	if (test_bit(NILFS_I_SHADOW, &ii->i_state)) {
 556		if (!args->for_shadow)
 557			return 0;
 558	} else if (args->for_shadow) {
 559		return 0;
 560	}
 561
 562	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 563		return !args->for_gc;
 564
 565	return args->for_gc && args->cno == ii->i_cno;
 566}
 567
 568static int nilfs_iget_set(struct inode *inode, void *opaque)
 569{
 570	struct nilfs_iget_args *args = opaque;
 571
 572	inode->i_ino = args->ino;
 573	NILFS_I(inode)->i_cno = args->cno;
 574	NILFS_I(inode)->i_root = args->root;
 575	if (args->root && args->ino == NILFS_ROOT_INO)
 576		nilfs_get_root(args->root);
 577
 578	if (args->for_gc)
 579		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 580	if (args->for_btnc)
 581		NILFS_I(inode)->i_state |= BIT(NILFS_I_BTNC);
 582	if (args->for_shadow)
 583		NILFS_I(inode)->i_state |= BIT(NILFS_I_SHADOW);
 584	return 0;
 585}
 586
 587struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 588			    unsigned long ino)
 589{
 590	struct nilfs_iget_args args = {
 591		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 592		.for_btnc = false, .for_shadow = false
 593	};
 594
 595	return ilookup5(sb, ino, nilfs_iget_test, &args);
 596}
 597
 598struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 599				unsigned long ino)
 600{
 601	struct nilfs_iget_args args = {
 602		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 603		.for_btnc = false, .for_shadow = false
 604	};
 605
 606	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 607}
 608
 609struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 610			 unsigned long ino)
 611{
 612	struct inode *inode;
 613	int err;
 614
 615	inode = nilfs_iget_locked(sb, root, ino);
 616	if (unlikely(!inode))
 617		return ERR_PTR(-ENOMEM);
 618	if (!(inode->i_state & I_NEW))
 619		return inode;
 620
 621	err = __nilfs_read_inode(sb, root, ino, inode);
 622	if (unlikely(err)) {
 623		iget_failed(inode);
 624		return ERR_PTR(err);
 625	}
 626	unlock_new_inode(inode);
 627	return inode;
 628}
 629
 630struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 631				__u64 cno)
 632{
 633	struct nilfs_iget_args args = {
 634		.ino = ino, .root = NULL, .cno = cno, .for_gc = true,
 635		.for_btnc = false, .for_shadow = false
 636	};
 637	struct inode *inode;
 638	int err;
 639
 640	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 641	if (unlikely(!inode))
 642		return ERR_PTR(-ENOMEM);
 643	if (!(inode->i_state & I_NEW))
 644		return inode;
 645
 646	err = nilfs_init_gcinode(inode);
 647	if (unlikely(err)) {
 648		iget_failed(inode);
 649		return ERR_PTR(err);
 650	}
 651	unlock_new_inode(inode);
 652	return inode;
 653}
 654
 655/**
 656 * nilfs_attach_btree_node_cache - attach a B-tree node cache to the inode
 657 * @inode: inode object
 658 *
 659 * nilfs_attach_btree_node_cache() attaches a B-tree node cache to @inode,
 660 * or does nothing if the inode already has it.  This function allocates
 661 * an additional inode to maintain page cache of B-tree nodes one-on-one.
 662 *
 663 * Return Value: On success, 0 is returned. On errors, one of the following
 664 * negative error code is returned.
 665 *
 666 * %-ENOMEM - Insufficient memory available.
 667 */
 668int nilfs_attach_btree_node_cache(struct inode *inode)
 669{
 670	struct nilfs_inode_info *ii = NILFS_I(inode);
 671	struct inode *btnc_inode;
 672	struct nilfs_iget_args args;
 673
 674	if (ii->i_assoc_inode)
 675		return 0;
 676
 677	args.ino = inode->i_ino;
 678	args.root = ii->i_root;
 679	args.cno = ii->i_cno;
 680	args.for_gc = test_bit(NILFS_I_GCINODE, &ii->i_state) != 0;
 681	args.for_btnc = true;
 682	args.for_shadow = test_bit(NILFS_I_SHADOW, &ii->i_state) != 0;
 683
 684	btnc_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 685				  nilfs_iget_set, &args);
 686	if (unlikely(!btnc_inode))
 687		return -ENOMEM;
 688	if (btnc_inode->i_state & I_NEW) {
 689		nilfs_init_btnc_inode(btnc_inode);
 690		unlock_new_inode(btnc_inode);
 691	}
 692	NILFS_I(btnc_inode)->i_assoc_inode = inode;
 693	NILFS_I(btnc_inode)->i_bmap = ii->i_bmap;
 694	ii->i_assoc_inode = btnc_inode;
 695
 696	return 0;
 697}
 698
 699/**
 700 * nilfs_detach_btree_node_cache - detach the B-tree node cache from the inode
 701 * @inode: inode object
 702 *
 703 * nilfs_detach_btree_node_cache() detaches the B-tree node cache and its
 704 * holder inode bound to @inode, or does nothing if @inode doesn't have it.
 705 */
 706void nilfs_detach_btree_node_cache(struct inode *inode)
 707{
 708	struct nilfs_inode_info *ii = NILFS_I(inode);
 709	struct inode *btnc_inode = ii->i_assoc_inode;
 710
 711	if (btnc_inode) {
 712		NILFS_I(btnc_inode)->i_assoc_inode = NULL;
 713		ii->i_assoc_inode = NULL;
 714		iput(btnc_inode);
 715	}
 716}
 717
 718/**
 719 * nilfs_iget_for_shadow - obtain inode for shadow mapping
 720 * @inode: inode object that uses shadow mapping
 721 *
 722 * nilfs_iget_for_shadow() allocates a pair of inodes that holds page
 723 * caches for shadow mapping.  The page cache for data pages is set up
 724 * in one inode and the one for b-tree node pages is set up in the
 725 * other inode, which is attached to the former inode.
 726 *
 727 * Return Value: On success, a pointer to the inode for data pages is
 728 * returned. On errors, one of the following negative error code is returned
 729 * in a pointer type.
 730 *
 731 * %-ENOMEM - Insufficient memory available.
 732 */
 733struct inode *nilfs_iget_for_shadow(struct inode *inode)
 734{
 735	struct nilfs_iget_args args = {
 736		.ino = inode->i_ino, .root = NULL, .cno = 0, .for_gc = false,
 737		.for_btnc = false, .for_shadow = true
 738	};
 739	struct inode *s_inode;
 740	int err;
 741
 742	s_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 743			       nilfs_iget_set, &args);
 744	if (unlikely(!s_inode))
 745		return ERR_PTR(-ENOMEM);
 746	if (!(s_inode->i_state & I_NEW))
 747		return inode;
 748
 749	NILFS_I(s_inode)->i_flags = 0;
 750	memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap));
 751	mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS);
 752
 753	err = nilfs_attach_btree_node_cache(s_inode);
 754	if (unlikely(err)) {
 755		iget_failed(s_inode);
 756		return ERR_PTR(err);
 757	}
 758	unlock_new_inode(s_inode);
 759	return s_inode;
 760}
 761
 762void nilfs_write_inode_common(struct inode *inode,
 763			      struct nilfs_inode *raw_inode, int has_bmap)
 764{
 765	struct nilfs_inode_info *ii = NILFS_I(inode);
 766
 767	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 768	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 769	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 770	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 771	raw_inode->i_size = cpu_to_le64(inode->i_size);
 772	raw_inode->i_ctime = cpu_to_le64(inode_get_ctime_sec(inode));
 773	raw_inode->i_mtime = cpu_to_le64(inode_get_mtime_sec(inode));
 774	raw_inode->i_ctime_nsec = cpu_to_le32(inode_get_ctime_nsec(inode));
 775	raw_inode->i_mtime_nsec = cpu_to_le32(inode_get_mtime_nsec(inode));
 776	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 777
 778	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 779	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 780
 781	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 782		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 783
 784		/* zero-fill unused portion in the case of super root block */
 785		raw_inode->i_xattr = 0;
 786		raw_inode->i_pad = 0;
 787		memset((void *)raw_inode + sizeof(*raw_inode), 0,
 788		       nilfs->ns_inode_size - sizeof(*raw_inode));
 789	}
 790
 791	if (has_bmap)
 792		nilfs_bmap_write(ii->i_bmap, raw_inode);
 793	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 794		raw_inode->i_device_code =
 795			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 796	/*
 797	 * When extending inode, nilfs->ns_inode_size should be checked
 798	 * for substitutions of appended fields.
 799	 */
 800}
 801
 802void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 803{
 804	ino_t ino = inode->i_ino;
 805	struct nilfs_inode_info *ii = NILFS_I(inode);
 806	struct inode *ifile = ii->i_root->ifile;
 807	struct nilfs_inode *raw_inode;
 808
 809	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 810
 811	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 812		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 813	if (flags & I_DIRTY_DATASYNC)
 814		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 815
 816	nilfs_write_inode_common(inode, raw_inode, 0);
 817		/*
 818		 * XXX: call with has_bmap = 0 is a workaround to avoid
 819		 * deadlock of bmap.  This delays update of i_bmap to just
 820		 * before writing.
 821		 */
 822
 823	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 824}
 825
 826#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
 827
 828static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 829				unsigned long from)
 830{
 831	__u64 b;
 832	int ret;
 833
 834	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 835		return;
 836repeat:
 837	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 838	if (ret == -ENOENT)
 839		return;
 840	else if (ret < 0)
 841		goto failed;
 842
 843	if (b < from)
 844		return;
 845
 846	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 847	ret = nilfs_bmap_truncate(ii->i_bmap, b);
 848	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 849	if (!ret || (ret == -ENOMEM &&
 850		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 851		goto repeat;
 852
 853failed:
 854	nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
 855		   ret, ii->vfs_inode.i_ino);
 856}
 857
 858void nilfs_truncate(struct inode *inode)
 859{
 860	unsigned long blkoff;
 861	unsigned int blocksize;
 862	struct nilfs_transaction_info ti;
 863	struct super_block *sb = inode->i_sb;
 864	struct nilfs_inode_info *ii = NILFS_I(inode);
 865
 866	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 867		return;
 868	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 869		return;
 870
 871	blocksize = sb->s_blocksize;
 872	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 873	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 874
 875	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 876
 877	nilfs_truncate_bmap(ii, blkoff);
 878
 879	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
 880	if (IS_SYNC(inode))
 881		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 882
 883	nilfs_mark_inode_dirty(inode);
 884	nilfs_set_file_dirty(inode, 0);
 885	nilfs_transaction_commit(sb);
 886	/*
 887	 * May construct a logical segment and may fail in sync mode.
 888	 * But truncate has no return value.
 889	 */
 890}
 891
 892static void nilfs_clear_inode(struct inode *inode)
 893{
 894	struct nilfs_inode_info *ii = NILFS_I(inode);
 895
 896	/*
 897	 * Free resources allocated in nilfs_read_inode(), here.
 898	 */
 899	BUG_ON(!list_empty(&ii->i_dirty));
 900	brelse(ii->i_bh);
 901	ii->i_bh = NULL;
 902
 903	if (nilfs_is_metadata_file_inode(inode))
 904		nilfs_mdt_clear(inode);
 905
 906	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 907		nilfs_bmap_clear(ii->i_bmap);
 908
 909	if (!test_bit(NILFS_I_BTNC, &ii->i_state))
 910		nilfs_detach_btree_node_cache(inode);
 911
 912	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 913		nilfs_put_root(ii->i_root);
 914}
 915
 916void nilfs_evict_inode(struct inode *inode)
 917{
 918	struct nilfs_transaction_info ti;
 919	struct super_block *sb = inode->i_sb;
 920	struct nilfs_inode_info *ii = NILFS_I(inode);
 921	struct the_nilfs *nilfs;
 922	int ret;
 923
 924	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 925		truncate_inode_pages_final(&inode->i_data);
 926		clear_inode(inode);
 927		nilfs_clear_inode(inode);
 928		return;
 929	}
 930	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 931
 932	truncate_inode_pages_final(&inode->i_data);
 933
 934	nilfs = sb->s_fs_info;
 935	if (unlikely(sb_rdonly(sb) || !nilfs->ns_writer)) {
 936		/*
 937		 * If this inode is about to be disposed after the file system
 938		 * has been degraded to read-only due to file system corruption
 939		 * or after the writer has been detached, do not make any
 940		 * changes that cause writes, just clear it.
 941		 * Do this check after read-locking ns_segctor_sem by
 942		 * nilfs_transaction_begin() in order to avoid a race with
 943		 * the writer detach operation.
 944		 */
 945		clear_inode(inode);
 946		nilfs_clear_inode(inode);
 947		nilfs_transaction_abort(sb);
 948		return;
 949	}
 950
 951	/* TODO: some of the following operations may fail.  */
 952	nilfs_truncate_bmap(ii, 0);
 953	nilfs_mark_inode_dirty(inode);
 954	clear_inode(inode);
 955
 956	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 957	if (!ret)
 958		atomic64_dec(&ii->i_root->inodes_count);
 959
 960	nilfs_clear_inode(inode);
 961
 962	if (IS_SYNC(inode))
 963		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 964	nilfs_transaction_commit(sb);
 965	/*
 966	 * May construct a logical segment and may fail in sync mode.
 967	 * But delete_inode has no return value.
 968	 */
 969}
 970
 971int nilfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 972		  struct iattr *iattr)
 973{
 974	struct nilfs_transaction_info ti;
 975	struct inode *inode = d_inode(dentry);
 976	struct super_block *sb = inode->i_sb;
 977	int err;
 978
 979	err = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 980	if (err)
 981		return err;
 982
 983	err = nilfs_transaction_begin(sb, &ti, 0);
 984	if (unlikely(err))
 985		return err;
 986
 987	if ((iattr->ia_valid & ATTR_SIZE) &&
 988	    iattr->ia_size != i_size_read(inode)) {
 989		inode_dio_wait(inode);
 990		truncate_setsize(inode, iattr->ia_size);
 991		nilfs_truncate(inode);
 992	}
 993
 994	setattr_copy(&nop_mnt_idmap, inode, iattr);
 995	mark_inode_dirty(inode);
 996
 997	if (iattr->ia_valid & ATTR_MODE) {
 998		err = nilfs_acl_chmod(inode);
 999		if (unlikely(err))
1000			goto out_err;
1001	}
1002
1003	return nilfs_transaction_commit(sb);
1004
1005out_err:
1006	nilfs_transaction_abort(sb);
1007	return err;
1008}
1009
1010int nilfs_permission(struct mnt_idmap *idmap, struct inode *inode,
1011		     int mask)
1012{
1013	struct nilfs_root *root = NILFS_I(inode)->i_root;
1014
1015	if ((mask & MAY_WRITE) && root &&
1016	    root->cno != NILFS_CPTREE_CURRENT_CNO)
1017		return -EROFS; /* snapshot is not writable */
1018
1019	return generic_permission(&nop_mnt_idmap, inode, mask);
1020}
1021
1022int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
1023{
1024	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1025	struct nilfs_inode_info *ii = NILFS_I(inode);
1026	int err;
1027
1028	spin_lock(&nilfs->ns_inode_lock);
1029	if (ii->i_bh == NULL || unlikely(!buffer_uptodate(ii->i_bh))) {
1030		spin_unlock(&nilfs->ns_inode_lock);
1031		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
1032						  inode->i_ino, pbh);
1033		if (unlikely(err))
1034			return err;
1035		spin_lock(&nilfs->ns_inode_lock);
1036		if (ii->i_bh == NULL)
1037			ii->i_bh = *pbh;
1038		else if (unlikely(!buffer_uptodate(ii->i_bh))) {
1039			__brelse(ii->i_bh);
1040			ii->i_bh = *pbh;
1041		} else {
1042			brelse(*pbh);
1043			*pbh = ii->i_bh;
1044		}
1045	} else
1046		*pbh = ii->i_bh;
1047
1048	get_bh(*pbh);
1049	spin_unlock(&nilfs->ns_inode_lock);
1050	return 0;
1051}
1052
1053int nilfs_inode_dirty(struct inode *inode)
1054{
1055	struct nilfs_inode_info *ii = NILFS_I(inode);
1056	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1057	int ret = 0;
1058
1059	if (!list_empty(&ii->i_dirty)) {
1060		spin_lock(&nilfs->ns_inode_lock);
1061		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
1062			test_bit(NILFS_I_BUSY, &ii->i_state);
1063		spin_unlock(&nilfs->ns_inode_lock);
1064	}
1065	return ret;
1066}
1067
1068int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
1069{
1070	struct nilfs_inode_info *ii = NILFS_I(inode);
1071	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1072
1073	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
1074
1075	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
1076		return 0;
1077
1078	spin_lock(&nilfs->ns_inode_lock);
1079	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
1080	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
1081		/*
1082		 * Because this routine may race with nilfs_dispose_list(),
1083		 * we have to check NILFS_I_QUEUED here, too.
1084		 */
1085		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
1086			/*
1087			 * This will happen when somebody is freeing
1088			 * this inode.
1089			 */
1090			nilfs_warn(inode->i_sb,
1091				   "cannot set file dirty (ino=%lu): the file is being freed",
1092				   inode->i_ino);
1093			spin_unlock(&nilfs->ns_inode_lock);
1094			return -EINVAL; /*
1095					 * NILFS_I_DIRTY may remain for
1096					 * freeing inode.
1097					 */
1098		}
1099		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
1100		set_bit(NILFS_I_QUEUED, &ii->i_state);
1101	}
1102	spin_unlock(&nilfs->ns_inode_lock);
1103	return 0;
1104}
1105
1106int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
1107{
1108	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1109	struct buffer_head *ibh;
1110	int err;
1111
1112	/*
1113	 * Do not dirty inodes after the log writer has been detached
1114	 * and its nilfs_root struct has been freed.
1115	 */
1116	if (unlikely(nilfs_purging(nilfs)))
1117		return 0;
1118
1119	err = nilfs_load_inode_block(inode, &ibh);
1120	if (unlikely(err)) {
1121		nilfs_warn(inode->i_sb,
1122			   "cannot mark inode dirty (ino=%lu): error %d loading inode block",
1123			   inode->i_ino, err);
1124		return err;
1125	}
1126	nilfs_update_inode(inode, ibh, flags);
1127	mark_buffer_dirty(ibh);
1128	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
1129	brelse(ibh);
1130	return 0;
1131}
1132
1133/**
1134 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
1135 * @inode: inode of the file to be registered.
1136 * @flags: flags to determine the dirty state of the inode
1137 *
1138 * nilfs_dirty_inode() loads a inode block containing the specified
1139 * @inode and copies data from a nilfs_inode to a corresponding inode
1140 * entry in the inode block. This operation is excluded from the segment
1141 * construction. This function can be called both as a single operation
1142 * and as a part of indivisible file operations.
1143 */
1144void nilfs_dirty_inode(struct inode *inode, int flags)
1145{
1146	struct nilfs_transaction_info ti;
1147	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
1148
1149	if (is_bad_inode(inode)) {
1150		nilfs_warn(inode->i_sb,
1151			   "tried to mark bad_inode dirty. ignored.");
1152		dump_stack();
1153		return;
1154	}
1155	if (mdi) {
1156		nilfs_mdt_mark_dirty(inode);
1157		return;
1158	}
1159	nilfs_transaction_begin(inode->i_sb, &ti, 0);
1160	__nilfs_mark_inode_dirty(inode, flags);
1161	nilfs_transaction_commit(inode->i_sb); /* never fails */
1162}
1163
1164int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1165		 __u64 start, __u64 len)
1166{
1167	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1168	__u64 logical = 0, phys = 0, size = 0;
1169	__u32 flags = 0;
1170	loff_t isize;
1171	sector_t blkoff, end_blkoff;
1172	sector_t delalloc_blkoff;
1173	unsigned long delalloc_blklen;
1174	unsigned int blkbits = inode->i_blkbits;
1175	int ret, n;
1176
1177	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
1178	if (ret)
1179		return ret;
1180
1181	inode_lock(inode);
1182
1183	isize = i_size_read(inode);
1184
1185	blkoff = start >> blkbits;
1186	end_blkoff = (start + len - 1) >> blkbits;
1187
1188	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1189							&delalloc_blkoff);
1190
1191	do {
1192		__u64 blkphy;
1193		unsigned int maxblocks;
1194
1195		if (delalloc_blklen && blkoff == delalloc_blkoff) {
1196			if (size) {
1197				/* End of the current extent */
1198				ret = fiemap_fill_next_extent(
1199					fieinfo, logical, phys, size, flags);
1200				if (ret)
1201					break;
1202			}
1203			if (blkoff > end_blkoff)
1204				break;
1205
1206			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1207			logical = blkoff << blkbits;
1208			phys = 0;
1209			size = delalloc_blklen << blkbits;
1210
1211			blkoff = delalloc_blkoff + delalloc_blklen;
1212			delalloc_blklen = nilfs_find_uncommitted_extent(
1213				inode, blkoff, &delalloc_blkoff);
1214			continue;
1215		}
1216
1217		/*
1218		 * Limit the number of blocks that we look up so as
1219		 * not to get into the next delayed allocation extent.
1220		 */
1221		maxblocks = INT_MAX;
1222		if (delalloc_blklen)
1223			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1224					  maxblocks);
1225		blkphy = 0;
1226
1227		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1228		n = nilfs_bmap_lookup_contig(
1229			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1230		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1231
1232		if (n < 0) {
1233			int past_eof;
1234
1235			if (unlikely(n != -ENOENT))
1236				break; /* error */
1237
1238			/* HOLE */
1239			blkoff++;
1240			past_eof = ((blkoff << blkbits) >= isize);
1241
1242			if (size) {
1243				/* End of the current extent */
1244
1245				if (past_eof)
1246					flags |= FIEMAP_EXTENT_LAST;
1247
1248				ret = fiemap_fill_next_extent(
1249					fieinfo, logical, phys, size, flags);
1250				if (ret)
1251					break;
1252				size = 0;
1253			}
1254			if (blkoff > end_blkoff || past_eof)
1255				break;
1256		} else {
1257			if (size) {
1258				if (phys && blkphy << blkbits == phys + size) {
1259					/* The current extent goes on */
1260					size += n << blkbits;
1261				} else {
1262					/* Terminate the current extent */
1263					ret = fiemap_fill_next_extent(
1264						fieinfo, logical, phys, size,
1265						flags);
1266					if (ret || blkoff > end_blkoff)
1267						break;
1268
1269					/* Start another extent */
1270					flags = FIEMAP_EXTENT_MERGED;
1271					logical = blkoff << blkbits;
1272					phys = blkphy << blkbits;
1273					size = n << blkbits;
1274				}
1275			} else {
1276				/* Start a new extent */
1277				flags = FIEMAP_EXTENT_MERGED;
1278				logical = blkoff << blkbits;
1279				phys = blkphy << blkbits;
1280				size = n << blkbits;
1281			}
1282			blkoff += n;
1283		}
1284		cond_resched();
1285	} while (true);
1286
1287	/* If ret is 1 then we just hit the end of the extent array */
1288	if (ret == 1)
1289		ret = 0;
1290
1291	inode_unlock(inode);
1292	return ret;
1293}