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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}
v5.14.15
   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 <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 */
  33struct nilfs_iget_args {
  34	u64 ino;
  35	__u64 cno;
  36	struct nilfs_root *root;
  37	int for_gc;
 
 
  38};
  39
  40static int nilfs_iget_test(struct inode *inode, void *opaque);
  41
  42void nilfs_inode_add_blocks(struct inode *inode, int n)
  43{
  44	struct nilfs_root *root = NILFS_I(inode)->i_root;
  45
  46	inode_add_bytes(inode, i_blocksize(inode) * n);
  47	if (root)
  48		atomic64_add(n, &root->blocks_count);
  49}
  50
  51void nilfs_inode_sub_blocks(struct inode *inode, int n)
  52{
  53	struct nilfs_root *root = NILFS_I(inode)->i_root;
  54
  55	inode_sub_bytes(inode, i_blocksize(inode) * n);
  56	if (root)
  57		atomic64_sub(n, &root->blocks_count);
  58}
  59
  60/**
  61 * nilfs_get_block() - get a file block on the filesystem (callback function)
  62 * @inode - inode struct of the target file
  63 * @blkoff - file block number
  64 * @bh_result - buffer head to be mapped on
  65 * @create - indicate whether allocating the block or not when it has not
  66 *      been allocated yet.
  67 *
  68 * This function does not issue actual read request of the specified data
  69 * block. It is done by VFS.
  70 */
  71int nilfs_get_block(struct inode *inode, sector_t blkoff,
  72		    struct buffer_head *bh_result, int create)
  73{
  74	struct nilfs_inode_info *ii = NILFS_I(inode);
  75	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
  76	__u64 blknum = 0;
  77	int err = 0, ret;
  78	unsigned int maxblocks = bh_result->b_size >> inode->i_blkbits;
  79
  80	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  81	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
  82	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
  83	if (ret >= 0) {	/* found */
  84		map_bh(bh_result, inode->i_sb, blknum);
  85		if (ret > 0)
  86			bh_result->b_size = (ret << inode->i_blkbits);
  87		goto out;
  88	}
  89	/* data block was not found */
  90	if (ret == -ENOENT && create) {
  91		struct nilfs_transaction_info ti;
  92
  93		bh_result->b_blocknr = 0;
  94		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
  95		if (unlikely(err))
  96			goto out;
  97		err = nilfs_bmap_insert(ii->i_bmap, blkoff,
  98					(unsigned long)bh_result);
  99		if (unlikely(err != 0)) {
 100			if (err == -EEXIST) {
 101				/*
 102				 * The get_block() function could be called
 103				 * from multiple callers for an inode.
 104				 * However, the page having this block must
 105				 * be locked in this case.
 106				 */
 107				nilfs_warn(inode->i_sb,
 108					   "%s (ino=%lu): a race condition while inserting a data block at offset=%llu",
 109					   __func__, inode->i_ino,
 110					   (unsigned long long)blkoff);
 111				err = 0;
 112			}
 113			nilfs_transaction_abort(inode->i_sb);
 114			goto out;
 115		}
 116		nilfs_mark_inode_dirty_sync(inode);
 117		nilfs_transaction_commit(inode->i_sb); /* never fails */
 118		/* Error handling should be detailed */
 119		set_buffer_new(bh_result);
 120		set_buffer_delay(bh_result);
 121		map_bh(bh_result, inode->i_sb, 0);
 122		/* Disk block number must be changed to proper value */
 123
 124	} else if (ret == -ENOENT) {
 125		/*
 126		 * not found is not error (e.g. hole); must return without
 127		 * the mapped state flag.
 128		 */
 129		;
 130	} else {
 131		err = ret;
 132	}
 133
 134 out:
 135	return err;
 136}
 137
 138/**
 139 * nilfs_readpage() - implement readpage() method of nilfs_aops {}
 140 * address_space_operations.
 141 * @file - file struct of the file to be read
 142 * @page - the page to be read
 143 */
 144static int nilfs_readpage(struct file *file, struct page *page)
 145{
 146	return mpage_readpage(page, nilfs_get_block);
 147}
 148
 149static void nilfs_readahead(struct readahead_control *rac)
 150{
 151	mpage_readahead(rac, nilfs_get_block);
 152}
 153
 154static int nilfs_writepages(struct address_space *mapping,
 155			    struct writeback_control *wbc)
 156{
 157	struct inode *inode = mapping->host;
 158	int err = 0;
 159
 160	if (sb_rdonly(inode->i_sb)) {
 161		nilfs_clear_dirty_pages(mapping, false);
 162		return -EROFS;
 163	}
 164
 165	if (wbc->sync_mode == WB_SYNC_ALL)
 166		err = nilfs_construct_dsync_segment(inode->i_sb, inode,
 167						    wbc->range_start,
 168						    wbc->range_end);
 169	return err;
 170}
 171
 172static int nilfs_writepage(struct page *page, struct writeback_control *wbc)
 173{
 174	struct inode *inode = page->mapping->host;
 175	int err;
 176
 177	if (sb_rdonly(inode->i_sb)) {
 178		/*
 179		 * It means that filesystem was remounted in read-only
 180		 * mode because of error or metadata corruption. But we
 181		 * have dirty pages that try to be flushed in background.
 182		 * So, here we simply discard this dirty page.
 183		 */
 184		nilfs_clear_dirty_page(page, false);
 185		unlock_page(page);
 186		return -EROFS;
 187	}
 188
 189	redirty_page_for_writepage(wbc, page);
 190	unlock_page(page);
 191
 192	if (wbc->sync_mode == WB_SYNC_ALL) {
 193		err = nilfs_construct_segment(inode->i_sb);
 194		if (unlikely(err))
 195			return err;
 196	} else if (wbc->for_reclaim)
 197		nilfs_flush_segment(inode->i_sb, inode->i_ino);
 198
 199	return 0;
 200}
 201
 202static int nilfs_set_page_dirty(struct page *page)
 
 203{
 204	struct inode *inode = page->mapping->host;
 205	int ret = __set_page_dirty_nobuffers(page);
 
 
 206
 207	if (page_has_buffers(page)) {
 208		unsigned int nr_dirty = 0;
 209		struct buffer_head *bh, *head;
 
 
 
 
 210
 211		/*
 212		 * This page is locked by callers, and no other thread
 213		 * concurrently marks its buffers dirty since they are
 214		 * only dirtied through routines in fs/buffer.c in
 215		 * which call sites of mark_buffer_dirty are protected
 216		 * by page lock.
 217		 */
 218		bh = head = page_buffers(page);
 219		do {
 220			/* Do not mark hole blocks dirty */
 221			if (buffer_dirty(bh) || !buffer_mapped(bh))
 222				continue;
 223
 224			set_buffer_dirty(bh);
 225			nr_dirty++;
 226		} while (bh = bh->b_this_page, bh != head);
 227
 228		if (nr_dirty)
 229			nilfs_set_file_dirty(inode, nr_dirty);
 230	} else if (ret) {
 231		unsigned int nr_dirty = 1 << (PAGE_SHIFT - inode->i_blkbits);
 
 
 232
 
 233		nilfs_set_file_dirty(inode, nr_dirty);
 234	}
 235	return ret;
 236}
 237
 238void nilfs_write_failed(struct address_space *mapping, loff_t to)
 239{
 240	struct inode *inode = mapping->host;
 241
 242	if (to > inode->i_size) {
 243		truncate_pagecache(inode, inode->i_size);
 244		nilfs_truncate(inode);
 245	}
 246}
 247
 248static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 249			     loff_t pos, unsigned len, unsigned flags,
 250			     struct page **pagep, void **fsdata)
 251
 252{
 253	struct inode *inode = mapping->host;
 254	int err = nilfs_transaction_begin(inode->i_sb, NULL, 1);
 255
 256	if (unlikely(err))
 257		return err;
 258
 259	err = block_write_begin(mapping, pos, len, flags, pagep,
 260				nilfs_get_block);
 261	if (unlikely(err)) {
 262		nilfs_write_failed(mapping, pos + len);
 263		nilfs_transaction_abort(inode->i_sb);
 264	}
 265	return err;
 266}
 267
 268static int nilfs_write_end(struct file *file, struct address_space *mapping,
 269			   loff_t pos, unsigned len, unsigned copied,
 270			   struct page *page, void *fsdata)
 271{
 272	struct inode *inode = mapping->host;
 273	unsigned int start = pos & (PAGE_SIZE - 1);
 274	unsigned int nr_dirty;
 275	int err;
 276
 277	nr_dirty = nilfs_page_count_clean_buffers(page, start,
 278						  start + copied);
 279	copied = generic_write_end(file, mapping, pos, len, copied, page,
 280				   fsdata);
 281	nilfs_set_file_dirty(inode, nr_dirty);
 282	err = nilfs_transaction_commit(inode->i_sb);
 283	return err ? : copied;
 284}
 285
 286static ssize_t
 287nilfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 288{
 289	struct inode *inode = file_inode(iocb->ki_filp);
 290
 291	if (iov_iter_rw(iter) == WRITE)
 292		return 0;
 293
 294	/* Needs synchronization with the cleaner */
 295	return blockdev_direct_IO(iocb, inode, iter, nilfs_get_block);
 296}
 297
 298const struct address_space_operations nilfs_aops = {
 299	.writepage		= nilfs_writepage,
 300	.readpage		= nilfs_readpage,
 301	.writepages		= nilfs_writepages,
 302	.set_page_dirty		= nilfs_set_page_dirty,
 303	.readahead		= nilfs_readahead,
 304	.write_begin		= nilfs_write_begin,
 305	.write_end		= nilfs_write_end,
 306	/* .releasepage		= nilfs_releasepage, */
 307	.invalidatepage		= block_invalidatepage,
 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 = 0
 
 318	};
 319
 320	return insert_inode_locked4(inode, ino, nilfs_iget_test, &args);
 321}
 322
 323struct inode *nilfs_new_inode(struct inode *dir, umode_t mode)
 324{
 325	struct super_block *sb = dir->i_sb;
 326	struct the_nilfs *nilfs = sb->s_fs_info;
 327	struct inode *inode;
 328	struct nilfs_inode_info *ii;
 329	struct nilfs_root *root;
 
 330	int err = -ENOMEM;
 331	ino_t ino;
 332
 333	inode = new_inode(sb);
 334	if (unlikely(!inode))
 335		goto failed;
 336
 337	mapping_set_gfp_mask(inode->i_mapping,
 338			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 339
 340	root = NILFS_I(dir)->i_root;
 341	ii = NILFS_I(inode);
 342	ii->i_state = BIT(NILFS_I_NEW);
 343	ii->i_root = root;
 344
 345	err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
 346	if (unlikely(err))
 347		goto failed_ifile_create_inode;
 348	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
 349
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 350	atomic64_inc(&root->inodes_count);
 351	inode_init_owner(&init_user_ns, inode, dir, mode);
 352	inode->i_ino = ino;
 353	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
 354
 355	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
 356		err = nilfs_bmap_read(ii->i_bmap, NULL);
 357		if (err < 0)
 358			goto failed_after_creation;
 359
 360		set_bit(NILFS_I_BMAP, &ii->i_state);
 361		/* No lock is needed; iget() ensures it. */
 362	}
 363
 364	ii->i_flags = nilfs_mask_flags(
 365		mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
 366
 367	/* ii->i_file_acl = 0; */
 368	/* ii->i_dir_acl = 0; */
 369	ii->i_dir_start_lookup = 0;
 370	nilfs_set_inode_flags(inode);
 371	spin_lock(&nilfs->ns_next_gen_lock);
 372	inode->i_generation = nilfs->ns_next_generation++;
 373	spin_unlock(&nilfs->ns_next_gen_lock);
 374	if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
 375		err = -EIO;
 376		goto failed_after_creation;
 377	}
 378
 379	err = nilfs_init_acl(inode, dir);
 380	if (unlikely(err))
 381		/*
 382		 * Never occur.  When supporting nilfs_init_acl(),
 383		 * proper cancellation of above jobs should be considered.
 384		 */
 385		goto failed_after_creation;
 386
 387	return inode;
 388
 389 failed_after_creation:
 390	clear_nlink(inode);
 391	if (inode->i_state & I_NEW)
 392		unlock_new_inode(inode);
 393	iput(inode);  /*
 394		       * raw_inode will be deleted through
 395		       * nilfs_evict_inode().
 396		       */
 397	goto failed;
 398
 399 failed_ifile_create_inode:
 400	make_bad_inode(inode);
 401	iput(inode);
 402 failed:
 403	return ERR_PTR(err);
 404}
 405
 406void nilfs_set_inode_flags(struct inode *inode)
 407{
 408	unsigned int flags = NILFS_I(inode)->i_flags;
 409	unsigned int new_fl = 0;
 410
 411	if (flags & FS_SYNC_FL)
 412		new_fl |= S_SYNC;
 413	if (flags & FS_APPEND_FL)
 414		new_fl |= S_APPEND;
 415	if (flags & FS_IMMUTABLE_FL)
 416		new_fl |= S_IMMUTABLE;
 417	if (flags & FS_NOATIME_FL)
 418		new_fl |= S_NOATIME;
 419	if (flags & FS_DIRSYNC_FL)
 420		new_fl |= S_DIRSYNC;
 421	inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
 422			S_NOATIME | S_DIRSYNC);
 423}
 424
 425int nilfs_read_inode_common(struct inode *inode,
 426			    struct nilfs_inode *raw_inode)
 427{
 428	struct nilfs_inode_info *ii = NILFS_I(inode);
 429	int err;
 430
 431	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
 432	i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
 433	i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
 434	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
 435	inode->i_size = le64_to_cpu(raw_inode->i_size);
 436	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 437	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
 438	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
 439	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 440	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
 441	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
 
 
 442	if (inode->i_nlink == 0)
 443		return -ESTALE; /* this inode is deleted */
 444
 445	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
 446	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
 447#if 0
 448	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
 449	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
 450		0 : le32_to_cpu(raw_inode->i_dir_acl);
 451#endif
 452	ii->i_dir_start_lookup = 0;
 453	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
 454
 455	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 456	    S_ISLNK(inode->i_mode)) {
 457		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
 458		if (err < 0)
 459			return err;
 460		set_bit(NILFS_I_BMAP, &ii->i_state);
 461		/* No lock is needed; iget() ensures it. */
 462	}
 463	return 0;
 464}
 465
 466static int __nilfs_read_inode(struct super_block *sb,
 467			      struct nilfs_root *root, unsigned long ino,
 468			      struct inode *inode)
 469{
 470	struct the_nilfs *nilfs = sb->s_fs_info;
 471	struct buffer_head *bh;
 472	struct nilfs_inode *raw_inode;
 473	int err;
 474
 475	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 476	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
 477	if (unlikely(err))
 478		goto bad_inode;
 479
 480	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
 481
 482	err = nilfs_read_inode_common(inode, raw_inode);
 483	if (err)
 484		goto failed_unmap;
 485
 486	if (S_ISREG(inode->i_mode)) {
 487		inode->i_op = &nilfs_file_inode_operations;
 488		inode->i_fop = &nilfs_file_operations;
 489		inode->i_mapping->a_ops = &nilfs_aops;
 490	} else if (S_ISDIR(inode->i_mode)) {
 491		inode->i_op = &nilfs_dir_inode_operations;
 492		inode->i_fop = &nilfs_dir_operations;
 493		inode->i_mapping->a_ops = &nilfs_aops;
 494	} else if (S_ISLNK(inode->i_mode)) {
 495		inode->i_op = &nilfs_symlink_inode_operations;
 496		inode_nohighmem(inode);
 497		inode->i_mapping->a_ops = &nilfs_aops;
 498	} else {
 499		inode->i_op = &nilfs_special_inode_operations;
 500		init_special_inode(
 501			inode, inode->i_mode,
 502			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
 503	}
 504	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 505	brelse(bh);
 506	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 507	nilfs_set_inode_flags(inode);
 508	mapping_set_gfp_mask(inode->i_mapping,
 509			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
 510	return 0;
 511
 512 failed_unmap:
 513	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
 514	brelse(bh);
 515
 516 bad_inode:
 517	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
 518	return err;
 519}
 520
 521static int nilfs_iget_test(struct inode *inode, void *opaque)
 522{
 523	struct nilfs_iget_args *args = opaque;
 524	struct nilfs_inode_info *ii;
 525
 526	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
 527		return 0;
 528
 529	ii = NILFS_I(inode);
 
 
 
 
 
 
 
 
 
 
 
 
 
 530	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
 531		return !args->for_gc;
 532
 533	return args->for_gc && args->cno == ii->i_cno;
 534}
 535
 536static int nilfs_iget_set(struct inode *inode, void *opaque)
 537{
 538	struct nilfs_iget_args *args = opaque;
 539
 540	inode->i_ino = args->ino;
 541	if (args->for_gc) {
 
 
 
 
 
 542		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
 543		NILFS_I(inode)->i_cno = args->cno;
 544		NILFS_I(inode)->i_root = NULL;
 545	} else {
 546		if (args->root && args->ino == NILFS_ROOT_INO)
 547			nilfs_get_root(args->root);
 548		NILFS_I(inode)->i_root = args->root;
 549	}
 550	return 0;
 551}
 552
 553struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
 554			    unsigned long ino)
 555{
 556	struct nilfs_iget_args args = {
 557		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 
 558	};
 559
 560	return ilookup5(sb, ino, nilfs_iget_test, &args);
 561}
 562
 563struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
 564				unsigned long ino)
 565{
 566	struct nilfs_iget_args args = {
 567		.ino = ino, .root = root, .cno = 0, .for_gc = 0
 
 568	};
 569
 570	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 571}
 572
 573struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
 574			 unsigned long ino)
 575{
 576	struct inode *inode;
 577	int err;
 578
 579	inode = nilfs_iget_locked(sb, root, ino);
 580	if (unlikely(!inode))
 581		return ERR_PTR(-ENOMEM);
 582	if (!(inode->i_state & I_NEW))
 583		return inode;
 584
 585	err = __nilfs_read_inode(sb, root, ino, inode);
 586	if (unlikely(err)) {
 587		iget_failed(inode);
 588		return ERR_PTR(err);
 589	}
 590	unlock_new_inode(inode);
 591	return inode;
 592}
 593
 594struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
 595				__u64 cno)
 596{
 597	struct nilfs_iget_args args = {
 598		.ino = ino, .root = NULL, .cno = cno, .for_gc = 1
 
 599	};
 600	struct inode *inode;
 601	int err;
 602
 603	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
 604	if (unlikely(!inode))
 605		return ERR_PTR(-ENOMEM);
 606	if (!(inode->i_state & I_NEW))
 607		return inode;
 608
 609	err = nilfs_init_gcinode(inode);
 610	if (unlikely(err)) {
 611		iget_failed(inode);
 612		return ERR_PTR(err);
 613	}
 614	unlock_new_inode(inode);
 615	return inode;
 616}
 617
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 618void nilfs_write_inode_common(struct inode *inode,
 619			      struct nilfs_inode *raw_inode, int has_bmap)
 620{
 621	struct nilfs_inode_info *ii = NILFS_I(inode);
 622
 623	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
 624	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
 625	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
 626	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
 627	raw_inode->i_size = cpu_to_le64(inode->i_size);
 628	raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
 629	raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
 630	raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
 631	raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
 632	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
 633
 634	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
 635	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
 636
 637	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
 638		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 639
 640		/* zero-fill unused portion in the case of super root block */
 641		raw_inode->i_xattr = 0;
 642		raw_inode->i_pad = 0;
 643		memset((void *)raw_inode + sizeof(*raw_inode), 0,
 644		       nilfs->ns_inode_size - sizeof(*raw_inode));
 645	}
 646
 647	if (has_bmap)
 648		nilfs_bmap_write(ii->i_bmap, raw_inode);
 649	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 650		raw_inode->i_device_code =
 651			cpu_to_le64(huge_encode_dev(inode->i_rdev));
 652	/*
 653	 * When extending inode, nilfs->ns_inode_size should be checked
 654	 * for substitutions of appended fields.
 655	 */
 656}
 657
 658void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
 659{
 660	ino_t ino = inode->i_ino;
 661	struct nilfs_inode_info *ii = NILFS_I(inode);
 662	struct inode *ifile = ii->i_root->ifile;
 663	struct nilfs_inode *raw_inode;
 664
 665	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
 666
 667	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
 668		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
 669	if (flags & I_DIRTY_DATASYNC)
 670		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
 671
 672	nilfs_write_inode_common(inode, raw_inode, 0);
 673		/*
 674		 * XXX: call with has_bmap = 0 is a workaround to avoid
 675		 * deadlock of bmap.  This delays update of i_bmap to just
 676		 * before writing.
 677		 */
 678
 679	nilfs_ifile_unmap_inode(ifile, ino, ibh);
 680}
 681
 682#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
 683
 684static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
 685				unsigned long from)
 686{
 687	__u64 b;
 688	int ret;
 689
 690	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 691		return;
 692repeat:
 693	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
 694	if (ret == -ENOENT)
 695		return;
 696	else if (ret < 0)
 697		goto failed;
 698
 699	if (b < from)
 700		return;
 701
 702	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
 703	ret = nilfs_bmap_truncate(ii->i_bmap, b);
 704	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
 705	if (!ret || (ret == -ENOMEM &&
 706		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
 707		goto repeat;
 708
 709failed:
 710	nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
 711		   ret, ii->vfs_inode.i_ino);
 712}
 713
 714void nilfs_truncate(struct inode *inode)
 715{
 716	unsigned long blkoff;
 717	unsigned int blocksize;
 718	struct nilfs_transaction_info ti;
 719	struct super_block *sb = inode->i_sb;
 720	struct nilfs_inode_info *ii = NILFS_I(inode);
 721
 722	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
 723		return;
 724	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
 725		return;
 726
 727	blocksize = sb->s_blocksize;
 728	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
 729	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 730
 731	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
 732
 733	nilfs_truncate_bmap(ii, blkoff);
 734
 735	inode->i_mtime = inode->i_ctime = current_time(inode);
 736	if (IS_SYNC(inode))
 737		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 738
 739	nilfs_mark_inode_dirty(inode);
 740	nilfs_set_file_dirty(inode, 0);
 741	nilfs_transaction_commit(sb);
 742	/*
 743	 * May construct a logical segment and may fail in sync mode.
 744	 * But truncate has no return value.
 745	 */
 746}
 747
 748static void nilfs_clear_inode(struct inode *inode)
 749{
 750	struct nilfs_inode_info *ii = NILFS_I(inode);
 751
 752	/*
 753	 * Free resources allocated in nilfs_read_inode(), here.
 754	 */
 755	BUG_ON(!list_empty(&ii->i_dirty));
 756	brelse(ii->i_bh);
 757	ii->i_bh = NULL;
 758
 759	if (nilfs_is_metadata_file_inode(inode))
 760		nilfs_mdt_clear(inode);
 761
 762	if (test_bit(NILFS_I_BMAP, &ii->i_state))
 763		nilfs_bmap_clear(ii->i_bmap);
 764
 765	nilfs_btnode_cache_clear(&ii->i_btnode_cache);
 
 766
 767	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
 768		nilfs_put_root(ii->i_root);
 769}
 770
 771void nilfs_evict_inode(struct inode *inode)
 772{
 773	struct nilfs_transaction_info ti;
 774	struct super_block *sb = inode->i_sb;
 775	struct nilfs_inode_info *ii = NILFS_I(inode);
 776	int ret;
 777
 778	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
 779		truncate_inode_pages_final(&inode->i_data);
 780		clear_inode(inode);
 781		nilfs_clear_inode(inode);
 782		return;
 783	}
 784	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
 785
 786	truncate_inode_pages_final(&inode->i_data);
 787
 788	/* TODO: some of the following operations may fail.  */
 789	nilfs_truncate_bmap(ii, 0);
 790	nilfs_mark_inode_dirty(inode);
 791	clear_inode(inode);
 792
 793	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
 794	if (!ret)
 795		atomic64_dec(&ii->i_root->inodes_count);
 796
 797	nilfs_clear_inode(inode);
 798
 799	if (IS_SYNC(inode))
 800		nilfs_set_transaction_flag(NILFS_TI_SYNC);
 801	nilfs_transaction_commit(sb);
 802	/*
 803	 * May construct a logical segment and may fail in sync mode.
 804	 * But delete_inode has no return value.
 805	 */
 806}
 807
 808int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
 809		  struct iattr *iattr)
 810{
 811	struct nilfs_transaction_info ti;
 812	struct inode *inode = d_inode(dentry);
 813	struct super_block *sb = inode->i_sb;
 814	int err;
 815
 816	err = setattr_prepare(&init_user_ns, dentry, iattr);
 817	if (err)
 818		return err;
 819
 820	err = nilfs_transaction_begin(sb, &ti, 0);
 821	if (unlikely(err))
 822		return err;
 823
 824	if ((iattr->ia_valid & ATTR_SIZE) &&
 825	    iattr->ia_size != i_size_read(inode)) {
 826		inode_dio_wait(inode);
 827		truncate_setsize(inode, iattr->ia_size);
 828		nilfs_truncate(inode);
 829	}
 830
 831	setattr_copy(&init_user_ns, inode, iattr);
 832	mark_inode_dirty(inode);
 833
 834	if (iattr->ia_valid & ATTR_MODE) {
 835		err = nilfs_acl_chmod(inode);
 836		if (unlikely(err))
 837			goto out_err;
 838	}
 839
 840	return nilfs_transaction_commit(sb);
 841
 842out_err:
 843	nilfs_transaction_abort(sb);
 844	return err;
 845}
 846
 847int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
 848		     int mask)
 849{
 850	struct nilfs_root *root = NILFS_I(inode)->i_root;
 851
 852	if ((mask & MAY_WRITE) && root &&
 853	    root->cno != NILFS_CPTREE_CURRENT_CNO)
 854		return -EROFS; /* snapshot is not writable */
 855
 856	return generic_permission(&init_user_ns, inode, mask);
 857}
 858
 859int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
 860{
 861	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 862	struct nilfs_inode_info *ii = NILFS_I(inode);
 863	int err;
 864
 865	spin_lock(&nilfs->ns_inode_lock);
 866	if (ii->i_bh == NULL) {
 867		spin_unlock(&nilfs->ns_inode_lock);
 868		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
 869						  inode->i_ino, pbh);
 870		if (unlikely(err))
 871			return err;
 872		spin_lock(&nilfs->ns_inode_lock);
 873		if (ii->i_bh == NULL)
 874			ii->i_bh = *pbh;
 875		else {
 876			brelse(*pbh);
 877			*pbh = ii->i_bh;
 878		}
 879	} else
 880		*pbh = ii->i_bh;
 881
 882	get_bh(*pbh);
 883	spin_unlock(&nilfs->ns_inode_lock);
 884	return 0;
 885}
 886
 887int nilfs_inode_dirty(struct inode *inode)
 888{
 889	struct nilfs_inode_info *ii = NILFS_I(inode);
 890	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 891	int ret = 0;
 892
 893	if (!list_empty(&ii->i_dirty)) {
 894		spin_lock(&nilfs->ns_inode_lock);
 895		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
 896			test_bit(NILFS_I_BUSY, &ii->i_state);
 897		spin_unlock(&nilfs->ns_inode_lock);
 898	}
 899	return ret;
 900}
 901
 902int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
 903{
 904	struct nilfs_inode_info *ii = NILFS_I(inode);
 905	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 906
 907	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
 908
 909	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
 910		return 0;
 911
 912	spin_lock(&nilfs->ns_inode_lock);
 913	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
 914	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
 915		/*
 916		 * Because this routine may race with nilfs_dispose_list(),
 917		 * we have to check NILFS_I_QUEUED here, too.
 918		 */
 919		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
 920			/*
 921			 * This will happen when somebody is freeing
 922			 * this inode.
 923			 */
 924			nilfs_warn(inode->i_sb,
 925				   "cannot set file dirty (ino=%lu): the file is being freed",
 926				   inode->i_ino);
 927			spin_unlock(&nilfs->ns_inode_lock);
 928			return -EINVAL; /*
 929					 * NILFS_I_DIRTY may remain for
 930					 * freeing inode.
 931					 */
 932		}
 933		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
 934		set_bit(NILFS_I_QUEUED, &ii->i_state);
 935	}
 936	spin_unlock(&nilfs->ns_inode_lock);
 937	return 0;
 938}
 939
 940int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
 941{
 942	struct buffer_head *ibh;
 943	int err;
 944
 945	err = nilfs_load_inode_block(inode, &ibh);
 946	if (unlikely(err)) {
 947		nilfs_warn(inode->i_sb,
 948			   "cannot mark inode dirty (ino=%lu): error %d loading inode block",
 949			   inode->i_ino, err);
 950		return err;
 951	}
 952	nilfs_update_inode(inode, ibh, flags);
 953	mark_buffer_dirty(ibh);
 954	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
 955	brelse(ibh);
 956	return 0;
 957}
 958
 959/**
 960 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
 961 * @inode: inode of the file to be registered.
 
 962 *
 963 * nilfs_dirty_inode() loads a inode block containing the specified
 964 * @inode and copies data from a nilfs_inode to a corresponding inode
 965 * entry in the inode block. This operation is excluded from the segment
 966 * construction. This function can be called both as a single operation
 967 * and as a part of indivisible file operations.
 968 */
 969void nilfs_dirty_inode(struct inode *inode, int flags)
 970{
 971	struct nilfs_transaction_info ti;
 972	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
 973
 974	if (is_bad_inode(inode)) {
 975		nilfs_warn(inode->i_sb,
 976			   "tried to mark bad_inode dirty. ignored.");
 977		dump_stack();
 978		return;
 979	}
 980	if (mdi) {
 981		nilfs_mdt_mark_dirty(inode);
 982		return;
 983	}
 984	nilfs_transaction_begin(inode->i_sb, &ti, 0);
 985	__nilfs_mark_inode_dirty(inode, flags);
 986	nilfs_transaction_commit(inode->i_sb); /* never fails */
 987}
 988
 989int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 990		 __u64 start, __u64 len)
 991{
 992	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
 993	__u64 logical = 0, phys = 0, size = 0;
 994	__u32 flags = 0;
 995	loff_t isize;
 996	sector_t blkoff, end_blkoff;
 997	sector_t delalloc_blkoff;
 998	unsigned long delalloc_blklen;
 999	unsigned int blkbits = inode->i_blkbits;
1000	int ret, n;
1001
1002	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
1003	if (ret)
1004		return ret;
1005
1006	inode_lock(inode);
1007
1008	isize = i_size_read(inode);
1009
1010	blkoff = start >> blkbits;
1011	end_blkoff = (start + len - 1) >> blkbits;
1012
1013	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
1014							&delalloc_blkoff);
1015
1016	do {
1017		__u64 blkphy;
1018		unsigned int maxblocks;
1019
1020		if (delalloc_blklen && blkoff == delalloc_blkoff) {
1021			if (size) {
1022				/* End of the current extent */
1023				ret = fiemap_fill_next_extent(
1024					fieinfo, logical, phys, size, flags);
1025				if (ret)
1026					break;
1027			}
1028			if (blkoff > end_blkoff)
1029				break;
1030
1031			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
1032			logical = blkoff << blkbits;
1033			phys = 0;
1034			size = delalloc_blklen << blkbits;
1035
1036			blkoff = delalloc_blkoff + delalloc_blklen;
1037			delalloc_blklen = nilfs_find_uncommitted_extent(
1038				inode, blkoff, &delalloc_blkoff);
1039			continue;
1040		}
1041
1042		/*
1043		 * Limit the number of blocks that we look up so as
1044		 * not to get into the next delayed allocation extent.
1045		 */
1046		maxblocks = INT_MAX;
1047		if (delalloc_blklen)
1048			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
1049					  maxblocks);
1050		blkphy = 0;
1051
1052		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1053		n = nilfs_bmap_lookup_contig(
1054			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
1055		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
1056
1057		if (n < 0) {
1058			int past_eof;
1059
1060			if (unlikely(n != -ENOENT))
1061				break; /* error */
1062
1063			/* HOLE */
1064			blkoff++;
1065			past_eof = ((blkoff << blkbits) >= isize);
1066
1067			if (size) {
1068				/* End of the current extent */
1069
1070				if (past_eof)
1071					flags |= FIEMAP_EXTENT_LAST;
1072
1073				ret = fiemap_fill_next_extent(
1074					fieinfo, logical, phys, size, flags);
1075				if (ret)
1076					break;
1077				size = 0;
1078			}
1079			if (blkoff > end_blkoff || past_eof)
1080				break;
1081		} else {
1082			if (size) {
1083				if (phys && blkphy << blkbits == phys + size) {
1084					/* The current extent goes on */
1085					size += n << blkbits;
1086				} else {
1087					/* Terminate the current extent */
1088					ret = fiemap_fill_next_extent(
1089						fieinfo, logical, phys, size,
1090						flags);
1091					if (ret || blkoff > end_blkoff)
1092						break;
1093
1094					/* Start another extent */
1095					flags = FIEMAP_EXTENT_MERGED;
1096					logical = blkoff << blkbits;
1097					phys = blkphy << blkbits;
1098					size = n << blkbits;
1099				}
1100			} else {
1101				/* Start a new extent */
1102				flags = FIEMAP_EXTENT_MERGED;
1103				logical = blkoff << blkbits;
1104				phys = blkphy << blkbits;
1105				size = n << blkbits;
1106			}
1107			blkoff += n;
1108		}
1109		cond_resched();
1110	} while (true);
1111
1112	/* If ret is 1 then we just hit the end of the extent array */
1113	if (ret == 1)
1114		ret = 0;
1115
1116	inode_unlock(inode);
1117	return ret;
1118}