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v6.2
   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 inode *inode = page->mapping->host;
 179	int err;
 180
 181	if (sb_rdonly(inode->i_sb)) {
 182		/*
 183		 * It means that filesystem was remounted in read-only
 184		 * mode because of error or metadata corruption. But we
 185		 * have dirty pages that try to be flushed in background.
 186		 * So, here we simply discard this dirty page.
 187		 */
 188		nilfs_clear_dirty_page(page, false);
 189		unlock_page(page);
 190		return -EROFS;
 191	}
 192
 193	redirty_page_for_writepage(wbc, page);
 194	unlock_page(page);
 195
 196	if (wbc->sync_mode == WB_SYNC_ALL) {
 197		err = nilfs_construct_segment(inode->i_sb);
 198		if (unlikely(err))
 199			return err;
 200	} else if (wbc->for_reclaim)
 201		nilfs_flush_segment(inode->i_sb, inode->i_ino);
 202
 203	return 0;
 204}
 205
 206static bool nilfs_dirty_folio(struct address_space *mapping,
 207		struct folio *folio)
 208{
 209	struct inode *inode = mapping->host;
 210	struct buffer_head *head;
 211	unsigned int nr_dirty = 0;
 212	bool ret = filemap_dirty_folio(mapping, folio);
 213
 214	/*
 215	 * The page may not be locked, eg if called from try_to_unmap_one()
 216	 */
 217	spin_lock(&mapping->private_lock);
 218	head = folio_buffers(folio);
 219	if (head) {
 220		struct buffer_head *bh = head;
 221
 
 
 
 
 
 
 
 
 222		do {
 223			/* Do not mark hole blocks dirty */
 224			if (buffer_dirty(bh) || !buffer_mapped(bh))
 225				continue;
 226
 227			set_buffer_dirty(bh);
 228			nr_dirty++;
 229		} while (bh = bh->b_this_page, bh != head);
 
 
 
 230	} else if (ret) {
 231		nr_dirty = 1 << (folio_shift(folio) - inode->i_blkbits);
 232	}
 233	spin_unlock(&mapping->private_lock);
 234
 235	if (nr_dirty)
 236		nilfs_set_file_dirty(inode, nr_dirty);
 
 237	return ret;
 238}
 239
 240void nilfs_write_failed(struct address_space *mapping, loff_t to)
 241{
 242	struct inode *inode = mapping->host;
 243
 244	if (to > inode->i_size) {
 245		truncate_pagecache(inode, inode->i_size);
 246		nilfs_truncate(inode);
 247	}
 248}
 249
 250static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 251			     loff_t pos, unsigned len,
 252			     struct page **pagep, void **fsdata)
 253
 254{
 255	struct inode *inode = mapping->host;
 256	int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 257
 258	if (unlikely(err))
 259		return err;
 260
 261	err = block_write_begin(mapping, pos, len, pagep, nilfs_get_block);
 
 262	if (unlikely(err)) {
 263		nilfs_write_failed(mapping, pos + len);
 264		nilfs_transaction_abort(inode->i_sb);
 265	}
 266	return err;
 267}
 268
 269static int nilfs_write_end(struct file *file, struct address_space *mapping,
 270			   loff_t pos, unsigned len, unsigned copied,
 271			   struct page *page, void *fsdata)
 272{
 273	struct inode *inode = mapping->host;
 274	unsigned int start = pos & (PAGE_SIZE - 1);
 275	unsigned int nr_dirty;
 276	int err;
 277
 278	nr_dirty = nilfs_page_count_clean_buffers(page, start,
 279						  start + copied);
 280	copied = generic_write_end(file, mapping, pos, len, copied, page,
 281				   fsdata);
 282	nilfs_set_file_dirty(inode, nr_dirty);
 283	err = nilfs_transaction_commit(inode->i_sb);
 284	return err ? : copied;
 285}
 286
 287static ssize_t
 288nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 289{
 290	struct inode *inode = file_inode(iocb->ki_filp);
 291
 292	if (iov_iter_rw(iter) == WRITE)
 293		return 0;
 294
 295	/* Needs synchronization with the cleaner */
 296	return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 297}
 298
 299const struct address_space_operations nilfs_aops = {
 300	.writepage		= nilfs_writepage,
 301	.read_folio		= nilfs_read_folio,
 302	.writepages		= nilfs_writepages,
 303	.dirty_folio		= nilfs_dirty_folio,
 304	.readahead		= nilfs_readahead,
 305	.write_begin		= nilfs_write_begin,
 306	.write_end		= nilfs_write_end,
 307	.invalidate_folio	= block_invalidate_folio,
 
 308	.direct_IO		= nilfs_direct_IO,
 309	.is_partially_uptodate  = block_is_partially_uptodate,
 310};
 311
 312static int nilfs_insert_inode_locked(struct inode *inode,
 313				     struct nilfs_root *root,
 314				     unsigned long ino)
 315{
 316	struct nilfs_iget_args args = {
 317		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 318		.for_btnc = false, .for_shadow = false
 319	};
 320
 321	return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 322}
 323
 324struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 325{
 326	struct super_block *sb = dir->i_sb;
 327	struct the_nilfs *nilfs = sb->s_fs_info;
 328	struct inode *inode;
 329	struct nilfs_inode_info *ii;
 330	struct nilfs_root *root;
 331	struct buffer_head *bh;
 332	int err = -ENOMEM;
 333	ino_t ino;
 334
 335	inode = new_inode(sb);
 336	if (unlikely(!inode))
 337		goto failed;
 338
 339	mapping_set_gfp_mask(inode->i_mapping,
 340			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 341
 342	root = NILFS_I(dir)->i_root;
 343	ii = NILFS_I(inode);
 344	ii->i_state = BIT(NILFS_I_NEW);
 345	ii->i_root = root;
 346
 347	err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 348	if (unlikely(err))
 349		goto failed_ifile_create_inode;
 350	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
 351
 352	if (unlikely(ino < NILFS_USER_INO)) {
 353		nilfs_warn(sb,
 354			   "inode bitmap is inconsistent for reserved inodes");
 355		do {
 356			brelse(bh);
 357			err = nilfs_ifile_create_inode(root->ifile, &ino, &bh);
 358			if (unlikely(err))
 359				goto failed_ifile_create_inode;
 360		} while (ino < NILFS_USER_INO);
 361
 362		nilfs_info(sb, "repaired inode bitmap for reserved inodes");
 363	}
 364	ii->i_bh = bh;
 365
 366	atomic64_inc(&root->inodes_count);
 367	inode_init_owner(&init_user_ns, inode, dir, mode);
 368	inode->i_ino = ino;
 369	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 370
 371	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 372		err = nilfs_bmap_read(ii->i_bmap, NULL);
 373		if (err < 0)
 374			goto failed_after_creation;
 375
 376		set_bit(NILFS_I_BMAP, &ii->i_state);
 377		/* No lock is needed; iget() ensures it. */
 378	}
 379
 380	ii->i_flags = nilfs_mask_flags(
 381		mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 382
 383	/* ii->i_file_acl = 0; */
 384	/* ii->i_dir_acl = 0; */
 385	ii->i_dir_start_lookup = 0;
 386	nilfs_set_inode_flags(inode);
 387	spin_lock(&nilfs->ns_next_gen_lock);
 388	inode->i_generation = nilfs->ns_next_generation++;
 389	spin_unlock(&nilfs->ns_next_gen_lock);
 390	if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 391		err = -EIO;
 392		goto failed_after_creation;
 393	}
 394
 395	err = nilfs_init_acl(inode, dir);
 396	if (unlikely(err))
 397		/*
 398		 * Never occur.  When supporting nilfs_init_acl(),
 399		 * proper cancellation of above jobs should be considered.
 400		 */
 401		goto failed_after_creation;
 402
 403	return inode;
 404
 405 failed_after_creation:
 406	clear_nlink(inode);
 407	if (inode->i_state & I_NEW)
 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 (nilfs_is_metadata_file_inode(inode) && !S_ISREG(inode->i_mode))
 459		return -EIO; /* this inode is for metadata and corrupted */
 460	if (inode->i_nlink == 0)
 461		return -ESTALE; /* this inode is deleted */
 462
 463	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 464	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 465#if 0
 466	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 467	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 468		0 : le32_to_cpu(raw_inode->i_dir_acl);
 469#endif
 470	ii->i_dir_start_lookup = 0;
 471	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 472
 473	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 474	    S_ISLNK(inode->i_mode)) {
 475		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 476		if (err < 0)
 477			return err;
 478		set_bit(NILFS_I_BMAP, &ii->i_state);
 479		/* No lock is needed; iget() ensures it. */
 480	}
 481	return 0;
 482}
 483
 484static int __nilfs_read_inode(struct super_block *sb,
 485			      struct nilfs_root *root, unsigned long ino,
 486			      struct inode *inode)
 487{
 488	struct the_nilfs *nilfs = sb->s_fs_info;
 489	struct buffer_head *bh;
 490	struct nilfs_inode *raw_inode;
 491	int err;
 492
 493	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 494	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 495	if (unlikely(err))
 496		goto bad_inode;
 497
 498	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 499
 500	err = nilfs_read_inode_common(inode, raw_inode);
 501	if (err)
 502		goto failed_unmap;
 503
 504	if (S_ISREG(inode->i_mode)) {
 505		inode->i_op = &nilfs_file_inode_operations;
 506		inode->i_fop = &nilfs_file_operations;
 507		inode->i_mapping->a_ops = &nilfs_aops;
 508	} else if (S_ISDIR(inode->i_mode)) {
 509		inode->i_op = &nilfs_dir_inode_operations;
 510		inode->i_fop = &nilfs_dir_operations;
 511		inode->i_mapping->a_ops = &nilfs_aops;
 512	} else if (S_ISLNK(inode->i_mode)) {
 513		inode->i_op = &nilfs_symlink_inode_operations;
 514		inode_nohighmem(inode);
 515		inode->i_mapping->a_ops = &nilfs_aops;
 516	} else {
 517		inode->i_op = &nilfs_special_inode_operations;
 518		init_special_inode(
 519			inode, inode->i_mode,
 520			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 521	}
 522	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 523	brelse(bh);
 524	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 525	nilfs_set_inode_flags(inode);
 526	mapping_set_gfp_mask(inode->i_mapping,
 527			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 528	return 0;
 529
 530 failed_unmap:
 531	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 532	brelse(bh);
 533
 534 bad_inode:
 535	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 536	return err;
 537}
 538
 539static int nilfs_iget_test(struct inode *inode, void *opaque)
 540{
 541	struct nilfs_iget_args *args = opaque;
 542	struct nilfs_inode_info *ii;
 543
 544	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 545		return 0;
 546
 547	ii = NILFS_I(inode);
 548	if (test_bit(NILFS_I_BTNC, &ii->i_state)) {
 549		if (!args->for_btnc)
 550			return 0;
 551	} else if (args->for_btnc) {
 552		return 0;
 553	}
 554	if (test_bit(NILFS_I_SHADOW, &ii->i_state)) {
 555		if (!args->for_shadow)
 556			return 0;
 557	} else if (args->for_shadow) {
 558		return 0;
 559	}
 560
 561	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 562		return !args->for_gc;
 563
 564	return args->for_gc && args->cno == ii->i_cno;
 565}
 566
 567static int nilfs_iget_set(struct inode *inode, void *opaque)
 568{
 569	struct nilfs_iget_args *args = opaque;
 570
 571	inode->i_ino = args->ino;
 572	NILFS_I(inode)->i_cno = args->cno;
 573	NILFS_I(inode)->i_root = args->root;
 574	if (args->root && args->ino == NILFS_ROOT_INO)
 575		nilfs_get_root(args->root);
 576
 577	if (args->for_gc)
 578		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 579	if (args->for_btnc)
 580		NILFS_I(inode)->i_state |= BIT(NILFS_I_BTNC);
 581	if (args->for_shadow)
 582		NILFS_I(inode)->i_state |= BIT(NILFS_I_SHADOW);
 
 
 
 583	return 0;
 584}
 585
 586struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 587			    unsigned long ino)
 588{
 589	struct nilfs_iget_args args = {
 590		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 591		.for_btnc = false, .for_shadow = false
 592	};
 593
 594	return ilookup5(sb, ino, nilfs_iget_test, &args);
 595}
 596
 597struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 598				unsigned long ino)
 599{
 600	struct nilfs_iget_args args = {
 601		.ino = ino, .root = root, .cno = 0, .for_gc = false,
 602		.for_btnc = false, .for_shadow = false
 603	};
 604
 605	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 606}
 607
 608struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 609			 unsigned long ino)
 610{
 611	struct inode *inode;
 612	int err;
 613
 614	inode = nilfs_iget_locked(sb, root, ino);
 615	if (unlikely(!inode))
 616		return ERR_PTR(-ENOMEM);
 617	if (!(inode->i_state & I_NEW))
 618		return inode;
 619
 620	err = __nilfs_read_inode(sb, root, ino, inode);
 621	if (unlikely(err)) {
 622		iget_failed(inode);
 623		return ERR_PTR(err);
 624	}
 625	unlock_new_inode(inode);
 626	return inode;
 627}
 628
 629struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 630				__u64 cno)
 631{
 632	struct nilfs_iget_args args = {
 633		.ino = ino, .root = NULL, .cno = cno, .for_gc = true,
 634		.for_btnc = false, .for_shadow = false
 635	};
 636	struct inode *inode;
 637	int err;
 638
 639	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 640	if (unlikely(!inode))
 641		return ERR_PTR(-ENOMEM);
 642	if (!(inode->i_state & I_NEW))
 643		return inode;
 644
 645	err = nilfs_init_gcinode(inode);
 646	if (unlikely(err)) {
 647		iget_failed(inode);
 648		return ERR_PTR(err);
 649	}
 650	unlock_new_inode(inode);
 651	return inode;
 652}
 653
 654/**
 655 * nilfs_attach_btree_node_cache - attach a B-tree node cache to the inode
 656 * @inode: inode object
 657 *
 658 * nilfs_attach_btree_node_cache() attaches a B-tree node cache to @inode,
 659 * or does nothing if the inode already has it.  This function allocates
 660 * an additional inode to maintain page cache of B-tree nodes one-on-one.
 661 *
 662 * Return Value: On success, 0 is returned. On errors, one of the following
 663 * negative error code is returned.
 664 *
 665 * %-ENOMEM - Insufficient memory available.
 666 */
 667int nilfs_attach_btree_node_cache(struct inode *inode)
 668{
 669	struct nilfs_inode_info *ii = NILFS_I(inode);
 670	struct inode *btnc_inode;
 671	struct nilfs_iget_args args;
 672
 673	if (ii->i_assoc_inode)
 674		return 0;
 675
 676	args.ino = inode->i_ino;
 677	args.root = ii->i_root;
 678	args.cno = ii->i_cno;
 679	args.for_gc = test_bit(NILFS_I_GCINODE, &ii->i_state) != 0;
 680	args.for_btnc = true;
 681	args.for_shadow = test_bit(NILFS_I_SHADOW, &ii->i_state) != 0;
 682
 683	btnc_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 684				  nilfs_iget_set, &args);
 685	if (unlikely(!btnc_inode))
 686		return -ENOMEM;
 687	if (btnc_inode->i_state & I_NEW) {
 688		nilfs_init_btnc_inode(btnc_inode);
 689		unlock_new_inode(btnc_inode);
 690	}
 691	NILFS_I(btnc_inode)->i_assoc_inode = inode;
 692	NILFS_I(btnc_inode)->i_bmap = ii->i_bmap;
 693	ii->i_assoc_inode = btnc_inode;
 694
 695	return 0;
 696}
 697
 698/**
 699 * nilfs_detach_btree_node_cache - detach the B-tree node cache from the inode
 700 * @inode: inode object
 701 *
 702 * nilfs_detach_btree_node_cache() detaches the B-tree node cache and its
 703 * holder inode bound to @inode, or does nothing if @inode doesn't have it.
 704 */
 705void nilfs_detach_btree_node_cache(struct inode *inode)
 706{
 707	struct nilfs_inode_info *ii = NILFS_I(inode);
 708	struct inode *btnc_inode = ii->i_assoc_inode;
 709
 710	if (btnc_inode) {
 711		NILFS_I(btnc_inode)->i_assoc_inode = NULL;
 712		ii->i_assoc_inode = NULL;
 713		iput(btnc_inode);
 714	}
 715}
 716
 717/**
 718 * nilfs_iget_for_shadow - obtain inode for shadow mapping
 719 * @inode: inode object that uses shadow mapping
 720 *
 721 * nilfs_iget_for_shadow() allocates a pair of inodes that holds page
 722 * caches for shadow mapping.  The page cache for data pages is set up
 723 * in one inode and the one for b-tree node pages is set up in the
 724 * other inode, which is attached to the former inode.
 725 *
 726 * Return Value: On success, a pointer to the inode for data pages is
 727 * returned. On errors, one of the following negative error code is returned
 728 * in a pointer type.
 729 *
 730 * %-ENOMEM - Insufficient memory available.
 731 */
 732struct inode *nilfs_iget_for_shadow(struct inode *inode)
 733{
 734	struct nilfs_iget_args args = {
 735		.ino = inode->i_ino, .root = NULL, .cno = 0, .for_gc = false,
 736		.for_btnc = false, .for_shadow = true
 737	};
 738	struct inode *s_inode;
 739	int err;
 740
 741	s_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
 742			       nilfs_iget_set, &args);
 743	if (unlikely(!s_inode))
 744		return ERR_PTR(-ENOMEM);
 745	if (!(s_inode->i_state & I_NEW))
 746		return inode;
 747
 748	NILFS_I(s_inode)->i_flags = 0;
 749	memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap));
 750	mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS);
 751
 752	err = nilfs_attach_btree_node_cache(s_inode);
 753	if (unlikely(err)) {
 754		iget_failed(s_inode);
 755		return ERR_PTR(err);
 756	}
 757	unlock_new_inode(s_inode);
 758	return s_inode;
 759}
 760
 761void nilfs_write_inode_common(struct inode *inode,
 762			      struct nilfs_inode *raw_inode, int has_bmap)
 763{
 764	struct nilfs_inode_info *ii = NILFS_I(inode);
 765
 766	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 767	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 768	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 769	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 770	raw_inode->i_size = cpu_to_le64(inode->i_size);
 771	raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 772	raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 773	raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 774	raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 775	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 776
 777	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 778	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 779
 780	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 781		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 782
 783		/* zero-fill unused portion in the case of super root block */
 784		raw_inode->i_xattr = 0;
 785		raw_inode->i_pad = 0;
 786		memset((void *)raw_inode + sizeof(*raw_inode), 0,
 787		       nilfs->ns_inode_size - sizeof(*raw_inode));
 788	}
 789
 790	if (has_bmap)
 791		nilfs_bmap_write(ii->i_bmap, raw_inode);
 792	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 793		raw_inode->i_device_code =
 794			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 795	/*
 796	 * When extending inode, nilfs->ns_inode_size should be checked
 797	 * for substitutions of appended fields.
 798	 */
 799}
 800
 801void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 802{
 803	ino_t ino = inode->i_ino;
 804	struct nilfs_inode_info *ii = NILFS_I(inode);
 805	struct inode *ifile = ii->i_root->ifile;
 806	struct nilfs_inode *raw_inode;
 807
 808	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 809
 810	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 811		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 812	if (flags & I_DIRTY_DATASYNC)
 813		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 814
 815	nilfs_write_inode_common(inode, raw_inode, 0);
 816		/*
 817		 * XXX: call with has_bmap = 0 is a workaround to avoid
 818		 * deadlock of bmap.  This delays update of i_bmap to just
 819		 * before writing.
 820		 */
 821
 822	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 823}
 824
 825#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
 826
 827static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 828				unsigned long from)
 829{
 830	__u64 b;
 831	int ret;
 832
 833	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 834		return;
 835repeat:
 836	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 837	if (ret == -ENOENT)
 838		return;
 839	else if (ret < 0)
 840		goto failed;
 841
 842	if (b < from)
 843		return;
 844
 845	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 846	ret = nilfs_bmap_truncate(ii->i_bmap, b);
 847	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 848	if (!ret || (ret == -ENOMEM &&
 849		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 850		goto repeat;
 851
 852failed:
 853	nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
 854		   ret, ii->vfs_inode.i_ino);
 
 855}
 856
 857void nilfs_truncate(struct inode *inode)
 858{
 859	unsigned long blkoff;
 860	unsigned int blocksize;
 861	struct nilfs_transaction_info ti;
 862	struct super_block *sb = inode->i_sb;
 863	struct nilfs_inode_info *ii = NILFS_I(inode);
 864
 865	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 866		return;
 867	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 868		return;
 869
 870	blocksize = sb->s_blocksize;
 871	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 872	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 873
 874	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 875
 876	nilfs_truncate_bmap(ii, blkoff);
 877
 878	inode->i_mtime = inode->i_ctime = current_time(inode);
 879	if (IS_SYNC(inode))
 880		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 881
 882	nilfs_mark_inode_dirty(inode);
 883	nilfs_set_file_dirty(inode, 0);
 884	nilfs_transaction_commit(sb);
 885	/*
 886	 * May construct a logical segment and may fail in sync mode.
 887	 * But truncate has no return value.
 888	 */
 889}
 890
 891static void nilfs_clear_inode(struct inode *inode)
 892{
 893	struct nilfs_inode_info *ii = NILFS_I(inode);
 894
 895	/*
 896	 * Free resources allocated in nilfs_read_inode(), here.
 897	 */
 898	BUG_ON(!list_empty(&ii->i_dirty));
 899	brelse(ii->i_bh);
 900	ii->i_bh = NULL;
 901
 902	if (nilfs_is_metadata_file_inode(inode))
 903		nilfs_mdt_clear(inode);
 904
 905	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 906		nilfs_bmap_clear(ii->i_bmap);
 907
 908	if (!test_bit(NILFS_I_BTNC, &ii->i_state))
 909		nilfs_detach_btree_node_cache(inode);
 910
 911	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 912		nilfs_put_root(ii->i_root);
 913}
 914
 915void nilfs_evict_inode(struct inode *inode)
 916{
 917	struct nilfs_transaction_info ti;
 918	struct super_block *sb = inode->i_sb;
 919	struct nilfs_inode_info *ii = NILFS_I(inode);
 920	int ret;
 921
 922	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 923		truncate_inode_pages_final(&inode->i_data);
 924		clear_inode(inode);
 925		nilfs_clear_inode(inode);
 926		return;
 927	}
 928	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 929
 930	truncate_inode_pages_final(&inode->i_data);
 931
 932	/* TODO: some of the following operations may fail.  */
 933	nilfs_truncate_bmap(ii, 0);
 934	nilfs_mark_inode_dirty(inode);
 935	clear_inode(inode);
 936
 937	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 938	if (!ret)
 939		atomic64_dec(&ii->i_root->inodes_count);
 940
 941	nilfs_clear_inode(inode);
 942
 943	if (IS_SYNC(inode))
 944		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 945	nilfs_transaction_commit(sb);
 946	/*
 947	 * May construct a logical segment and may fail in sync mode.
 948	 * But delete_inode has no return value.
 949	 */
 950}
 951
 952int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 953		  struct iattr *iattr)
 954{
 955	struct nilfs_transaction_info ti;
 956	struct inode *inode = d_inode(dentry);
 957	struct super_block *sb = inode->i_sb;
 958	int err;
 959
 960	err = setattr_prepare(&init_user_ns, dentry, iattr);
 961	if (err)
 962		return err;
 963
 964	err = nilfs_transaction_begin(sb, &ti, 0);
 965	if (unlikely(err))
 966		return err;
 967
 968	if ((iattr->ia_valid & ATTR_SIZE) &&
 969	    iattr->ia_size != i_size_read(inode)) {
 970		inode_dio_wait(inode);
 971		truncate_setsize(inode, iattr->ia_size);
 972		nilfs_truncate(inode);
 973	}
 974
 975	setattr_copy(&init_user_ns, inode, iattr);
 976	mark_inode_dirty(inode);
 977
 978	if (iattr->ia_valid & ATTR_MODE) {
 979		err = nilfs_acl_chmod(inode);
 980		if (unlikely(err))
 981			goto out_err;
 982	}
 983
 984	return nilfs_transaction_commit(sb);
 985
 986out_err:
 987	nilfs_transaction_abort(sb);
 988	return err;
 989}
 990
 991int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 992		     int mask)
 993{
 994	struct nilfs_root *root = NILFS_I(inode)->i_root;
 995
 996	if ((mask & MAY_WRITE) && root &&
 997	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 998		return -EROFS; /* snapshot is not writable */
 999
1000	return generic_permission(&init_user_ns, inode, mask);
1001}
1002
1003int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
1004{
1005	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1006	struct nilfs_inode_info *ii = NILFS_I(inode);
1007	int err;
1008
1009	spin_lock(&nilfs->ns_inode_lock);
1010	if (ii->i_bh == NULL) {
1011		spin_unlock(&nilfs->ns_inode_lock);
1012		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
1013						  inode->i_ino, pbh);
1014		if (unlikely(err))
1015			return err;
1016		spin_lock(&nilfs->ns_inode_lock);
1017		if (ii->i_bh == NULL)
1018			ii->i_bh = *pbh;
1019		else {
1020			brelse(*pbh);
1021			*pbh = ii->i_bh;
1022		}
1023	} else
1024		*pbh = ii->i_bh;
1025
1026	get_bh(*pbh);
1027	spin_unlock(&nilfs->ns_inode_lock);
1028	return 0;
1029}
1030
1031int nilfs_inode_dirty(struct inode *inode)
1032{
1033	struct nilfs_inode_info *ii = NILFS_I(inode);
1034	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1035	int ret = 0;
1036
1037	if (!list_empty(&ii->i_dirty)) {
1038		spin_lock(&nilfs->ns_inode_lock);
1039		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
1040			test_bit(NILFS_I_BUSY, &ii->i_state);
1041		spin_unlock(&nilfs->ns_inode_lock);
1042	}
1043	return ret;
1044}
1045
1046int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
1047{
1048	struct nilfs_inode_info *ii = NILFS_I(inode);
1049	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1050
1051	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
1052
1053	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
1054		return 0;
1055
1056	spin_lock(&nilfs->ns_inode_lock);
1057	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
1058	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
1059		/*
1060		 * Because this routine may race with nilfs_dispose_list(),
1061		 * we have to check NILFS_I_QUEUED here, too.
1062		 */
1063		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
1064			/*
1065			 * This will happen when somebody is freeing
1066			 * this inode.
1067			 */
1068			nilfs_warn(inode->i_sb,
1069				   "cannot set file dirty (ino=%lu): the file is being freed",
1070				   inode->i_ino);
1071			spin_unlock(&nilfs->ns_inode_lock);
1072			return -EINVAL; /*
1073					 * NILFS_I_DIRTY may remain for
1074					 * freeing inode.
1075					 */
1076		}
1077		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
1078		set_bit(NILFS_I_QUEUED, &ii->i_state);
1079	}
1080	spin_unlock(&nilfs->ns_inode_lock);
1081	return 0;
1082}
1083
1084int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
1085{
1086	struct buffer_head *ibh;
1087	int err;
1088
1089	err = nilfs_load_inode_block(inode, &ibh);
1090	if (unlikely(err)) {
1091		nilfs_warn(inode->i_sb,
1092			   "cannot mark inode dirty (ino=%lu): error %d loading inode block",
1093			   inode->i_ino, err);
1094		return err;
1095	}
1096	nilfs_update_inode(inode, ibh, flags);
1097	mark_buffer_dirty(ibh);
1098	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
1099	brelse(ibh);
1100	return 0;
1101}
1102
1103/**
1104 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
1105 * @inode: inode of the file to be registered.
1106 * @flags: flags to determine the dirty state of the inode
1107 *
1108 * nilfs_dirty_inode() loads a inode block containing the specified
1109 * @inode and copies data from a nilfs_inode to a corresponding inode
1110 * entry in the inode block. This operation is excluded from the segment
1111 * construction. This function can be called both as a single operation
1112 * and as a part of indivisible file operations.
1113 */
1114void nilfs_dirty_inode(struct inode *inode, int flags)
1115{
1116	struct nilfs_transaction_info ti;
1117	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
1118
1119	if (is_bad_inode(inode)) {
1120		nilfs_warn(inode->i_sb,
1121			   "tried to mark bad_inode dirty. ignored.");
1122		dump_stack();
1123		return;
1124	}
1125	if (mdi) {
1126		nilfs_mdt_mark_dirty(inode);
1127		return;
1128	}
1129	nilfs_transaction_begin(inode->i_sb, &ti, 0);
1130	__nilfs_mark_inode_dirty(inode, flags);
1131	nilfs_transaction_commit(inode->i_sb); /* never fails */
1132}
1133
1134int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1135		 __u64 start, __u64 len)
1136{
1137	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
1138	__u64 logical = 0, phys = 0, size = 0;
1139	__u32 flags = 0;
1140	loff_t isize;
1141	sector_t blkoff, end_blkoff;
1142	sector_t delalloc_blkoff;
1143	unsigned long delalloc_blklen;
1144	unsigned int blkbits = inode->i_blkbits;
1145	int ret, n;
1146
1147	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
1148	if (ret)
1149		return ret;
1150
1151	inode_lock(inode);
1152
1153	isize = i_size_read(inode);
1154
1155	blkoff = start >> blkbits;
1156	end_blkoff = (start + len - 1) >> blkbits;
1157
1158	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1159							&delalloc_blkoff);
1160
1161	do {
1162		__u64 blkphy;
1163		unsigned int maxblocks;
1164
1165		if (delalloc_blklen && blkoff == delalloc_blkoff) {
1166			if (size) {
1167				/* End of the current extent */
1168				ret = fiemap_fill_next_extent(
1169					fieinfo, logical, phys, size, flags);
1170				if (ret)
1171					break;
1172			}
1173			if (blkoff > end_blkoff)
1174				break;
1175
1176			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1177			logical = blkoff << blkbits;
1178			phys = 0;
1179			size = delalloc_blklen << blkbits;
1180
1181			blkoff = delalloc_blkoff + delalloc_blklen;
1182			delalloc_blklen = nilfs_find_uncommitted_extent(
1183				inode, blkoff, &delalloc_blkoff);
1184			continue;
1185		}
1186
1187		/*
1188		 * Limit the number of blocks that we look up so as
1189		 * not to get into the next delayed allocation extent.
1190		 */
1191		maxblocks = INT_MAX;
1192		if (delalloc_blklen)
1193			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1194					  maxblocks);
1195		blkphy = 0;
1196
1197		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1198		n = nilfs_bmap_lookup_contig(
1199			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1200		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1201
1202		if (n < 0) {
1203			int past_eof;
1204
1205			if (unlikely(n != -ENOENT))
1206				break; /* error */
1207
1208			/* HOLE */
1209			blkoff++;
1210			past_eof = ((blkoff << blkbits) >= isize);
1211
1212			if (size) {
1213				/* End of the current extent */
1214
1215				if (past_eof)
1216					flags |= FIEMAP_EXTENT_LAST;
1217
1218				ret = fiemap_fill_next_extent(
1219					fieinfo, logical, phys, size, flags);
1220				if (ret)
1221					break;
1222				size = 0;
1223			}
1224			if (blkoff > end_blkoff || past_eof)
1225				break;
1226		} else {
1227			if (size) {
1228				if (phys && blkphy << blkbits == phys + size) {
1229					/* The current extent goes on */
1230					size += n << blkbits;
1231				} else {
1232					/* Terminate the current extent */
1233					ret = fiemap_fill_next_extent(
1234						fieinfo, logical, phys, size,
1235						flags);
1236					if (ret || blkoff > end_blkoff)
1237						break;
1238
1239					/* Start another extent */
1240					flags = FIEMAP_EXTENT_MERGED;
1241					logical = blkoff << blkbits;
1242					phys = blkphy << blkbits;
1243					size = n << blkbits;
1244				}
1245			} else {
1246				/* Start a new extent */
1247				flags = FIEMAP_EXTENT_MERGED;
1248				logical = blkoff << blkbits;
1249				phys = blkphy << blkbits;
1250				size = n << blkbits;
1251			}
1252			blkoff += n;
1253		}
1254		cond_resched();
1255	} while (true);
1256
1257	/* If ret is 1 then we just hit the end of the extent array */
1258	if (ret == 1)
1259		ret = 0;
1260
1261	inode_unlock(inode);
1262	return ret;
1263}
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}