cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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inode.c (33049B)


      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	int err = -ENOMEM;
    332	ino_t ino;
    333
    334	inode = new_inode(sb);
    335	if (unlikely(!inode))
    336		goto failed;
    337
    338	mapping_set_gfp_mask(inode->i_mapping,
    339			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
    340
    341	root = NILFS_I(dir)->i_root;
    342	ii = NILFS_I(inode);
    343	ii->i_state = BIT(NILFS_I_NEW);
    344	ii->i_root = root;
    345
    346	err = nilfs_ifile_create_inode(root->ifile, &ino, &ii->i_bh);
    347	if (unlikely(err))
    348		goto failed_ifile_create_inode;
    349	/* reference count of i_bh inherits from nilfs_mdt_read_block() */
    350
    351	atomic64_inc(&root->inodes_count);
    352	inode_init_owner(&init_user_ns, inode, dir, mode);
    353	inode->i_ino = ino;
    354	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
    355
    356	if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
    357		err = nilfs_bmap_read(ii->i_bmap, NULL);
    358		if (err < 0)
    359			goto failed_after_creation;
    360
    361		set_bit(NILFS_I_BMAP, &ii->i_state);
    362		/* No lock is needed; iget() ensures it. */
    363	}
    364
    365	ii->i_flags = nilfs_mask_flags(
    366		mode, NILFS_I(dir)->i_flags & NILFS_FL_INHERITED);
    367
    368	/* ii->i_file_acl = 0; */
    369	/* ii->i_dir_acl = 0; */
    370	ii->i_dir_start_lookup = 0;
    371	nilfs_set_inode_flags(inode);
    372	spin_lock(&nilfs->ns_next_gen_lock);
    373	inode->i_generation = nilfs->ns_next_generation++;
    374	spin_unlock(&nilfs->ns_next_gen_lock);
    375	if (nilfs_insert_inode_locked(inode, root, ino) < 0) {
    376		err = -EIO;
    377		goto failed_after_creation;
    378	}
    379
    380	err = nilfs_init_acl(inode, dir);
    381	if (unlikely(err))
    382		/*
    383		 * Never occur.  When supporting nilfs_init_acl(),
    384		 * proper cancellation of above jobs should be considered.
    385		 */
    386		goto failed_after_creation;
    387
    388	return inode;
    389
    390 failed_after_creation:
    391	clear_nlink(inode);
    392	if (inode->i_state & I_NEW)
    393		unlock_new_inode(inode);
    394	iput(inode);  /*
    395		       * raw_inode will be deleted through
    396		       * nilfs_evict_inode().
    397		       */
    398	goto failed;
    399
    400 failed_ifile_create_inode:
    401	make_bad_inode(inode);
    402	iput(inode);
    403 failed:
    404	return ERR_PTR(err);
    405}
    406
    407void nilfs_set_inode_flags(struct inode *inode)
    408{
    409	unsigned int flags = NILFS_I(inode)->i_flags;
    410	unsigned int new_fl = 0;
    411
    412	if (flags & FS_SYNC_FL)
    413		new_fl |= S_SYNC;
    414	if (flags & FS_APPEND_FL)
    415		new_fl |= S_APPEND;
    416	if (flags & FS_IMMUTABLE_FL)
    417		new_fl |= S_IMMUTABLE;
    418	if (flags & FS_NOATIME_FL)
    419		new_fl |= S_NOATIME;
    420	if (flags & FS_DIRSYNC_FL)
    421		new_fl |= S_DIRSYNC;
    422	inode_set_flags(inode, new_fl, S_SYNC | S_APPEND | S_IMMUTABLE |
    423			S_NOATIME | S_DIRSYNC);
    424}
    425
    426int nilfs_read_inode_common(struct inode *inode,
    427			    struct nilfs_inode *raw_inode)
    428{
    429	struct nilfs_inode_info *ii = NILFS_I(inode);
    430	int err;
    431
    432	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
    433	i_uid_write(inode, le32_to_cpu(raw_inode->i_uid));
    434	i_gid_write(inode, le32_to_cpu(raw_inode->i_gid));
    435	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
    436	inode->i_size = le64_to_cpu(raw_inode->i_size);
    437	inode->i_atime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
    438	inode->i_ctime.tv_sec = le64_to_cpu(raw_inode->i_ctime);
    439	inode->i_mtime.tv_sec = le64_to_cpu(raw_inode->i_mtime);
    440	inode->i_atime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
    441	inode->i_ctime.tv_nsec = le32_to_cpu(raw_inode->i_ctime_nsec);
    442	inode->i_mtime.tv_nsec = le32_to_cpu(raw_inode->i_mtime_nsec);
    443	if (inode->i_nlink == 0)
    444		return -ESTALE; /* this inode is deleted */
    445
    446	inode->i_blocks = le64_to_cpu(raw_inode->i_blocks);
    447	ii->i_flags = le32_to_cpu(raw_inode->i_flags);
    448#if 0
    449	ii->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
    450	ii->i_dir_acl = S_ISREG(inode->i_mode) ?
    451		0 : le32_to_cpu(raw_inode->i_dir_acl);
    452#endif
    453	ii->i_dir_start_lookup = 0;
    454	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
    455
    456	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
    457	    S_ISLNK(inode->i_mode)) {
    458		err = nilfs_bmap_read(ii->i_bmap, raw_inode);
    459		if (err < 0)
    460			return err;
    461		set_bit(NILFS_I_BMAP, &ii->i_state);
    462		/* No lock is needed; iget() ensures it. */
    463	}
    464	return 0;
    465}
    466
    467static int __nilfs_read_inode(struct super_block *sb,
    468			      struct nilfs_root *root, unsigned long ino,
    469			      struct inode *inode)
    470{
    471	struct the_nilfs *nilfs = sb->s_fs_info;
    472	struct buffer_head *bh;
    473	struct nilfs_inode *raw_inode;
    474	int err;
    475
    476	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
    477	err = nilfs_ifile_get_inode_block(root->ifile, ino, &bh);
    478	if (unlikely(err))
    479		goto bad_inode;
    480
    481	raw_inode = nilfs_ifile_map_inode(root->ifile, ino, bh);
    482
    483	err = nilfs_read_inode_common(inode, raw_inode);
    484	if (err)
    485		goto failed_unmap;
    486
    487	if (S_ISREG(inode->i_mode)) {
    488		inode->i_op = &nilfs_file_inode_operations;
    489		inode->i_fop = &nilfs_file_operations;
    490		inode->i_mapping->a_ops = &nilfs_aops;
    491	} else if (S_ISDIR(inode->i_mode)) {
    492		inode->i_op = &nilfs_dir_inode_operations;
    493		inode->i_fop = &nilfs_dir_operations;
    494		inode->i_mapping->a_ops = &nilfs_aops;
    495	} else if (S_ISLNK(inode->i_mode)) {
    496		inode->i_op = &nilfs_symlink_inode_operations;
    497		inode_nohighmem(inode);
    498		inode->i_mapping->a_ops = &nilfs_aops;
    499	} else {
    500		inode->i_op = &nilfs_special_inode_operations;
    501		init_special_inode(
    502			inode, inode->i_mode,
    503			huge_decode_dev(le64_to_cpu(raw_inode->i_device_code)));
    504	}
    505	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
    506	brelse(bh);
    507	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
    508	nilfs_set_inode_flags(inode);
    509	mapping_set_gfp_mask(inode->i_mapping,
    510			   mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS));
    511	return 0;
    512
    513 failed_unmap:
    514	nilfs_ifile_unmap_inode(root->ifile, ino, bh);
    515	brelse(bh);
    516
    517 bad_inode:
    518	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
    519	return err;
    520}
    521
    522static int nilfs_iget_test(struct inode *inode, void *opaque)
    523{
    524	struct nilfs_iget_args *args = opaque;
    525	struct nilfs_inode_info *ii;
    526
    527	if (args->ino != inode->i_ino || args->root != NILFS_I(inode)->i_root)
    528		return 0;
    529
    530	ii = NILFS_I(inode);
    531	if (test_bit(NILFS_I_BTNC, &ii->i_state)) {
    532		if (!args->for_btnc)
    533			return 0;
    534	} else if (args->for_btnc) {
    535		return 0;
    536	}
    537	if (test_bit(NILFS_I_SHADOW, &ii->i_state)) {
    538		if (!args->for_shadow)
    539			return 0;
    540	} else if (args->for_shadow) {
    541		return 0;
    542	}
    543
    544	if (!test_bit(NILFS_I_GCINODE, &ii->i_state))
    545		return !args->for_gc;
    546
    547	return args->for_gc && args->cno == ii->i_cno;
    548}
    549
    550static int nilfs_iget_set(struct inode *inode, void *opaque)
    551{
    552	struct nilfs_iget_args *args = opaque;
    553
    554	inode->i_ino = args->ino;
    555	NILFS_I(inode)->i_cno = args->cno;
    556	NILFS_I(inode)->i_root = args->root;
    557	if (args->root && args->ino == NILFS_ROOT_INO)
    558		nilfs_get_root(args->root);
    559
    560	if (args->for_gc)
    561		NILFS_I(inode)->i_state = BIT(NILFS_I_GCINODE);
    562	if (args->for_btnc)
    563		NILFS_I(inode)->i_state |= BIT(NILFS_I_BTNC);
    564	if (args->for_shadow)
    565		NILFS_I(inode)->i_state |= BIT(NILFS_I_SHADOW);
    566	return 0;
    567}
    568
    569struct inode *nilfs_ilookup(struct super_block *sb, struct nilfs_root *root,
    570			    unsigned long ino)
    571{
    572	struct nilfs_iget_args args = {
    573		.ino = ino, .root = root, .cno = 0, .for_gc = false,
    574		.for_btnc = false, .for_shadow = false
    575	};
    576
    577	return ilookup5(sb, ino, nilfs_iget_test, &args);
    578}
    579
    580struct inode *nilfs_iget_locked(struct super_block *sb, struct nilfs_root *root,
    581				unsigned long ino)
    582{
    583	struct nilfs_iget_args args = {
    584		.ino = ino, .root = root, .cno = 0, .for_gc = false,
    585		.for_btnc = false, .for_shadow = false
    586	};
    587
    588	return iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
    589}
    590
    591struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root,
    592			 unsigned long ino)
    593{
    594	struct inode *inode;
    595	int err;
    596
    597	inode = nilfs_iget_locked(sb, root, ino);
    598	if (unlikely(!inode))
    599		return ERR_PTR(-ENOMEM);
    600	if (!(inode->i_state & I_NEW))
    601		return inode;
    602
    603	err = __nilfs_read_inode(sb, root, ino, inode);
    604	if (unlikely(err)) {
    605		iget_failed(inode);
    606		return ERR_PTR(err);
    607	}
    608	unlock_new_inode(inode);
    609	return inode;
    610}
    611
    612struct inode *nilfs_iget_for_gc(struct super_block *sb, unsigned long ino,
    613				__u64 cno)
    614{
    615	struct nilfs_iget_args args = {
    616		.ino = ino, .root = NULL, .cno = cno, .for_gc = true,
    617		.for_btnc = false, .for_shadow = false
    618	};
    619	struct inode *inode;
    620	int err;
    621
    622	inode = iget5_locked(sb, ino, nilfs_iget_test, nilfs_iget_set, &args);
    623	if (unlikely(!inode))
    624		return ERR_PTR(-ENOMEM);
    625	if (!(inode->i_state & I_NEW))
    626		return inode;
    627
    628	err = nilfs_init_gcinode(inode);
    629	if (unlikely(err)) {
    630		iget_failed(inode);
    631		return ERR_PTR(err);
    632	}
    633	unlock_new_inode(inode);
    634	return inode;
    635}
    636
    637/**
    638 * nilfs_attach_btree_node_cache - attach a B-tree node cache to the inode
    639 * @inode: inode object
    640 *
    641 * nilfs_attach_btree_node_cache() attaches a B-tree node cache to @inode,
    642 * or does nothing if the inode already has it.  This function allocates
    643 * an additional inode to maintain page cache of B-tree nodes one-on-one.
    644 *
    645 * Return Value: On success, 0 is returned. On errors, one of the following
    646 * negative error code is returned.
    647 *
    648 * %-ENOMEM - Insufficient memory available.
    649 */
    650int nilfs_attach_btree_node_cache(struct inode *inode)
    651{
    652	struct nilfs_inode_info *ii = NILFS_I(inode);
    653	struct inode *btnc_inode;
    654	struct nilfs_iget_args args;
    655
    656	if (ii->i_assoc_inode)
    657		return 0;
    658
    659	args.ino = inode->i_ino;
    660	args.root = ii->i_root;
    661	args.cno = ii->i_cno;
    662	args.for_gc = test_bit(NILFS_I_GCINODE, &ii->i_state) != 0;
    663	args.for_btnc = true;
    664	args.for_shadow = test_bit(NILFS_I_SHADOW, &ii->i_state) != 0;
    665
    666	btnc_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
    667				  nilfs_iget_set, &args);
    668	if (unlikely(!btnc_inode))
    669		return -ENOMEM;
    670	if (btnc_inode->i_state & I_NEW) {
    671		nilfs_init_btnc_inode(btnc_inode);
    672		unlock_new_inode(btnc_inode);
    673	}
    674	NILFS_I(btnc_inode)->i_assoc_inode = inode;
    675	NILFS_I(btnc_inode)->i_bmap = ii->i_bmap;
    676	ii->i_assoc_inode = btnc_inode;
    677
    678	return 0;
    679}
    680
    681/**
    682 * nilfs_detach_btree_node_cache - detach the B-tree node cache from the inode
    683 * @inode: inode object
    684 *
    685 * nilfs_detach_btree_node_cache() detaches the B-tree node cache and its
    686 * holder inode bound to @inode, or does nothing if @inode doesn't have it.
    687 */
    688void nilfs_detach_btree_node_cache(struct inode *inode)
    689{
    690	struct nilfs_inode_info *ii = NILFS_I(inode);
    691	struct inode *btnc_inode = ii->i_assoc_inode;
    692
    693	if (btnc_inode) {
    694		NILFS_I(btnc_inode)->i_assoc_inode = NULL;
    695		ii->i_assoc_inode = NULL;
    696		iput(btnc_inode);
    697	}
    698}
    699
    700/**
    701 * nilfs_iget_for_shadow - obtain inode for shadow mapping
    702 * @inode: inode object that uses shadow mapping
    703 *
    704 * nilfs_iget_for_shadow() allocates a pair of inodes that holds page
    705 * caches for shadow mapping.  The page cache for data pages is set up
    706 * in one inode and the one for b-tree node pages is set up in the
    707 * other inode, which is attached to the former inode.
    708 *
    709 * Return Value: On success, a pointer to the inode for data pages is
    710 * returned. On errors, one of the following negative error code is returned
    711 * in a pointer type.
    712 *
    713 * %-ENOMEM - Insufficient memory available.
    714 */
    715struct inode *nilfs_iget_for_shadow(struct inode *inode)
    716{
    717	struct nilfs_iget_args args = {
    718		.ino = inode->i_ino, .root = NULL, .cno = 0, .for_gc = false,
    719		.for_btnc = false, .for_shadow = true
    720	};
    721	struct inode *s_inode;
    722	int err;
    723
    724	s_inode = iget5_locked(inode->i_sb, inode->i_ino, nilfs_iget_test,
    725			       nilfs_iget_set, &args);
    726	if (unlikely(!s_inode))
    727		return ERR_PTR(-ENOMEM);
    728	if (!(s_inode->i_state & I_NEW))
    729		return inode;
    730
    731	NILFS_I(s_inode)->i_flags = 0;
    732	memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap));
    733	mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS);
    734
    735	err = nilfs_attach_btree_node_cache(s_inode);
    736	if (unlikely(err)) {
    737		iget_failed(s_inode);
    738		return ERR_PTR(err);
    739	}
    740	unlock_new_inode(s_inode);
    741	return s_inode;
    742}
    743
    744void nilfs_write_inode_common(struct inode *inode,
    745			      struct nilfs_inode *raw_inode, int has_bmap)
    746{
    747	struct nilfs_inode_info *ii = NILFS_I(inode);
    748
    749	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
    750	raw_inode->i_uid = cpu_to_le32(i_uid_read(inode));
    751	raw_inode->i_gid = cpu_to_le32(i_gid_read(inode));
    752	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
    753	raw_inode->i_size = cpu_to_le64(inode->i_size);
    754	raw_inode->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
    755	raw_inode->i_mtime = cpu_to_le64(inode->i_mtime.tv_sec);
    756	raw_inode->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
    757	raw_inode->i_mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
    758	raw_inode->i_blocks = cpu_to_le64(inode->i_blocks);
    759
    760	raw_inode->i_flags = cpu_to_le32(ii->i_flags);
    761	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
    762
    763	if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) {
    764		struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
    765
    766		/* zero-fill unused portion in the case of super root block */
    767		raw_inode->i_xattr = 0;
    768		raw_inode->i_pad = 0;
    769		memset((void *)raw_inode + sizeof(*raw_inode), 0,
    770		       nilfs->ns_inode_size - sizeof(*raw_inode));
    771	}
    772
    773	if (has_bmap)
    774		nilfs_bmap_write(ii->i_bmap, raw_inode);
    775	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
    776		raw_inode->i_device_code =
    777			cpu_to_le64(huge_encode_dev(inode->i_rdev));
    778	/*
    779	 * When extending inode, nilfs->ns_inode_size should be checked
    780	 * for substitutions of appended fields.
    781	 */
    782}
    783
    784void nilfs_update_inode(struct inode *inode, struct buffer_head *ibh, int flags)
    785{
    786	ino_t ino = inode->i_ino;
    787	struct nilfs_inode_info *ii = NILFS_I(inode);
    788	struct inode *ifile = ii->i_root->ifile;
    789	struct nilfs_inode *raw_inode;
    790
    791	raw_inode = nilfs_ifile_map_inode(ifile, ino, ibh);
    792
    793	if (test_and_clear_bit(NILFS_I_NEW, &ii->i_state))
    794		memset(raw_inode, 0, NILFS_MDT(ifile)->mi_entry_size);
    795	if (flags & I_DIRTY_DATASYNC)
    796		set_bit(NILFS_I_INODE_SYNC, &ii->i_state);
    797
    798	nilfs_write_inode_common(inode, raw_inode, 0);
    799		/*
    800		 * XXX: call with has_bmap = 0 is a workaround to avoid
    801		 * deadlock of bmap.  This delays update of i_bmap to just
    802		 * before writing.
    803		 */
    804
    805	nilfs_ifile_unmap_inode(ifile, ino, ibh);
    806}
    807
    808#define NILFS_MAX_TRUNCATE_BLOCKS	16384  /* 64MB for 4KB block */
    809
    810static void nilfs_truncate_bmap(struct nilfs_inode_info *ii,
    811				unsigned long from)
    812{
    813	__u64 b;
    814	int ret;
    815
    816	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
    817		return;
    818repeat:
    819	ret = nilfs_bmap_last_key(ii->i_bmap, &b);
    820	if (ret == -ENOENT)
    821		return;
    822	else if (ret < 0)
    823		goto failed;
    824
    825	if (b < from)
    826		return;
    827
    828	b -= min_t(__u64, NILFS_MAX_TRUNCATE_BLOCKS, b - from);
    829	ret = nilfs_bmap_truncate(ii->i_bmap, b);
    830	nilfs_relax_pressure_in_lock(ii->vfs_inode.i_sb);
    831	if (!ret || (ret == -ENOMEM &&
    832		     nilfs_bmap_truncate(ii->i_bmap, b) == 0))
    833		goto repeat;
    834
    835failed:
    836	nilfs_warn(ii->vfs_inode.i_sb, "error %d truncating bmap (ino=%lu)",
    837		   ret, ii->vfs_inode.i_ino);
    838}
    839
    840void nilfs_truncate(struct inode *inode)
    841{
    842	unsigned long blkoff;
    843	unsigned int blocksize;
    844	struct nilfs_transaction_info ti;
    845	struct super_block *sb = inode->i_sb;
    846	struct nilfs_inode_info *ii = NILFS_I(inode);
    847
    848	if (!test_bit(NILFS_I_BMAP, &ii->i_state))
    849		return;
    850	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
    851		return;
    852
    853	blocksize = sb->s_blocksize;
    854	blkoff = (inode->i_size + blocksize - 1) >> sb->s_blocksize_bits;
    855	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
    856
    857	block_truncate_page(inode->i_mapping, inode->i_size, nilfs_get_block);
    858
    859	nilfs_truncate_bmap(ii, blkoff);
    860
    861	inode->i_mtime = inode->i_ctime = current_time(inode);
    862	if (IS_SYNC(inode))
    863		nilfs_set_transaction_flag(NILFS_TI_SYNC);
    864
    865	nilfs_mark_inode_dirty(inode);
    866	nilfs_set_file_dirty(inode, 0);
    867	nilfs_transaction_commit(sb);
    868	/*
    869	 * May construct a logical segment and may fail in sync mode.
    870	 * But truncate has no return value.
    871	 */
    872}
    873
    874static void nilfs_clear_inode(struct inode *inode)
    875{
    876	struct nilfs_inode_info *ii = NILFS_I(inode);
    877
    878	/*
    879	 * Free resources allocated in nilfs_read_inode(), here.
    880	 */
    881	BUG_ON(!list_empty(&ii->i_dirty));
    882	brelse(ii->i_bh);
    883	ii->i_bh = NULL;
    884
    885	if (nilfs_is_metadata_file_inode(inode))
    886		nilfs_mdt_clear(inode);
    887
    888	if (test_bit(NILFS_I_BMAP, &ii->i_state))
    889		nilfs_bmap_clear(ii->i_bmap);
    890
    891	if (!test_bit(NILFS_I_BTNC, &ii->i_state))
    892		nilfs_detach_btree_node_cache(inode);
    893
    894	if (ii->i_root && inode->i_ino == NILFS_ROOT_INO)
    895		nilfs_put_root(ii->i_root);
    896}
    897
    898void nilfs_evict_inode(struct inode *inode)
    899{
    900	struct nilfs_transaction_info ti;
    901	struct super_block *sb = inode->i_sb;
    902	struct nilfs_inode_info *ii = NILFS_I(inode);
    903	int ret;
    904
    905	if (inode->i_nlink || !ii->i_root || unlikely(is_bad_inode(inode))) {
    906		truncate_inode_pages_final(&inode->i_data);
    907		clear_inode(inode);
    908		nilfs_clear_inode(inode);
    909		return;
    910	}
    911	nilfs_transaction_begin(sb, &ti, 0); /* never fails */
    912
    913	truncate_inode_pages_final(&inode->i_data);
    914
    915	/* TODO: some of the following operations may fail.  */
    916	nilfs_truncate_bmap(ii, 0);
    917	nilfs_mark_inode_dirty(inode);
    918	clear_inode(inode);
    919
    920	ret = nilfs_ifile_delete_inode(ii->i_root->ifile, inode->i_ino);
    921	if (!ret)
    922		atomic64_dec(&ii->i_root->inodes_count);
    923
    924	nilfs_clear_inode(inode);
    925
    926	if (IS_SYNC(inode))
    927		nilfs_set_transaction_flag(NILFS_TI_SYNC);
    928	nilfs_transaction_commit(sb);
    929	/*
    930	 * May construct a logical segment and may fail in sync mode.
    931	 * But delete_inode has no return value.
    932	 */
    933}
    934
    935int nilfs_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
    936		  struct iattr *iattr)
    937{
    938	struct nilfs_transaction_info ti;
    939	struct inode *inode = d_inode(dentry);
    940	struct super_block *sb = inode->i_sb;
    941	int err;
    942
    943	err = setattr_prepare(&init_user_ns, dentry, iattr);
    944	if (err)
    945		return err;
    946
    947	err = nilfs_transaction_begin(sb, &ti, 0);
    948	if (unlikely(err))
    949		return err;
    950
    951	if ((iattr->ia_valid & ATTR_SIZE) &&
    952	    iattr->ia_size != i_size_read(inode)) {
    953		inode_dio_wait(inode);
    954		truncate_setsize(inode, iattr->ia_size);
    955		nilfs_truncate(inode);
    956	}
    957
    958	setattr_copy(&init_user_ns, inode, iattr);
    959	mark_inode_dirty(inode);
    960
    961	if (iattr->ia_valid & ATTR_MODE) {
    962		err = nilfs_acl_chmod(inode);
    963		if (unlikely(err))
    964			goto out_err;
    965	}
    966
    967	return nilfs_transaction_commit(sb);
    968
    969out_err:
    970	nilfs_transaction_abort(sb);
    971	return err;
    972}
    973
    974int nilfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
    975		     int mask)
    976{
    977	struct nilfs_root *root = NILFS_I(inode)->i_root;
    978
    979	if ((mask & MAY_WRITE) && root &&
    980	    root->cno != NILFS_CPTREE_CURRENT_CNO)
    981		return -EROFS; /* snapshot is not writable */
    982
    983	return generic_permission(&init_user_ns, inode, mask);
    984}
    985
    986int nilfs_load_inode_block(struct inode *inode, struct buffer_head **pbh)
    987{
    988	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
    989	struct nilfs_inode_info *ii = NILFS_I(inode);
    990	int err;
    991
    992	spin_lock(&nilfs->ns_inode_lock);
    993	if (ii->i_bh == NULL) {
    994		spin_unlock(&nilfs->ns_inode_lock);
    995		err = nilfs_ifile_get_inode_block(ii->i_root->ifile,
    996						  inode->i_ino, pbh);
    997		if (unlikely(err))
    998			return err;
    999		spin_lock(&nilfs->ns_inode_lock);
   1000		if (ii->i_bh == NULL)
   1001			ii->i_bh = *pbh;
   1002		else {
   1003			brelse(*pbh);
   1004			*pbh = ii->i_bh;
   1005		}
   1006	} else
   1007		*pbh = ii->i_bh;
   1008
   1009	get_bh(*pbh);
   1010	spin_unlock(&nilfs->ns_inode_lock);
   1011	return 0;
   1012}
   1013
   1014int nilfs_inode_dirty(struct inode *inode)
   1015{
   1016	struct nilfs_inode_info *ii = NILFS_I(inode);
   1017	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
   1018	int ret = 0;
   1019
   1020	if (!list_empty(&ii->i_dirty)) {
   1021		spin_lock(&nilfs->ns_inode_lock);
   1022		ret = test_bit(NILFS_I_DIRTY, &ii->i_state) ||
   1023			test_bit(NILFS_I_BUSY, &ii->i_state);
   1024		spin_unlock(&nilfs->ns_inode_lock);
   1025	}
   1026	return ret;
   1027}
   1028
   1029int nilfs_set_file_dirty(struct inode *inode, unsigned int nr_dirty)
   1030{
   1031	struct nilfs_inode_info *ii = NILFS_I(inode);
   1032	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
   1033
   1034	atomic_add(nr_dirty, &nilfs->ns_ndirtyblks);
   1035
   1036	if (test_and_set_bit(NILFS_I_DIRTY, &ii->i_state))
   1037		return 0;
   1038
   1039	spin_lock(&nilfs->ns_inode_lock);
   1040	if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
   1041	    !test_bit(NILFS_I_BUSY, &ii->i_state)) {
   1042		/*
   1043		 * Because this routine may race with nilfs_dispose_list(),
   1044		 * we have to check NILFS_I_QUEUED here, too.
   1045		 */
   1046		if (list_empty(&ii->i_dirty) && igrab(inode) == NULL) {
   1047			/*
   1048			 * This will happen when somebody is freeing
   1049			 * this inode.
   1050			 */
   1051			nilfs_warn(inode->i_sb,
   1052				   "cannot set file dirty (ino=%lu): the file is being freed",
   1053				   inode->i_ino);
   1054			spin_unlock(&nilfs->ns_inode_lock);
   1055			return -EINVAL; /*
   1056					 * NILFS_I_DIRTY may remain for
   1057					 * freeing inode.
   1058					 */
   1059		}
   1060		list_move_tail(&ii->i_dirty, &nilfs->ns_dirty_files);
   1061		set_bit(NILFS_I_QUEUED, &ii->i_state);
   1062	}
   1063	spin_unlock(&nilfs->ns_inode_lock);
   1064	return 0;
   1065}
   1066
   1067int __nilfs_mark_inode_dirty(struct inode *inode, int flags)
   1068{
   1069	struct buffer_head *ibh;
   1070	int err;
   1071
   1072	err = nilfs_load_inode_block(inode, &ibh);
   1073	if (unlikely(err)) {
   1074		nilfs_warn(inode->i_sb,
   1075			   "cannot mark inode dirty (ino=%lu): error %d loading inode block",
   1076			   inode->i_ino, err);
   1077		return err;
   1078	}
   1079	nilfs_update_inode(inode, ibh, flags);
   1080	mark_buffer_dirty(ibh);
   1081	nilfs_mdt_mark_dirty(NILFS_I(inode)->i_root->ifile);
   1082	brelse(ibh);
   1083	return 0;
   1084}
   1085
   1086/**
   1087 * nilfs_dirty_inode - reflect changes on given inode to an inode block.
   1088 * @inode: inode of the file to be registered.
   1089 * @flags: flags to determine the dirty state of the inode
   1090 *
   1091 * nilfs_dirty_inode() loads a inode block containing the specified
   1092 * @inode and copies data from a nilfs_inode to a corresponding inode
   1093 * entry in the inode block. This operation is excluded from the segment
   1094 * construction. This function can be called both as a single operation
   1095 * and as a part of indivisible file operations.
   1096 */
   1097void nilfs_dirty_inode(struct inode *inode, int flags)
   1098{
   1099	struct nilfs_transaction_info ti;
   1100	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
   1101
   1102	if (is_bad_inode(inode)) {
   1103		nilfs_warn(inode->i_sb,
   1104			   "tried to mark bad_inode dirty. ignored.");
   1105		dump_stack();
   1106		return;
   1107	}
   1108	if (mdi) {
   1109		nilfs_mdt_mark_dirty(inode);
   1110		return;
   1111	}
   1112	nilfs_transaction_begin(inode->i_sb, &ti, 0);
   1113	__nilfs_mark_inode_dirty(inode, flags);
   1114	nilfs_transaction_commit(inode->i_sb); /* never fails */
   1115}
   1116
   1117int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
   1118		 __u64 start, __u64 len)
   1119{
   1120	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
   1121	__u64 logical = 0, phys = 0, size = 0;
   1122	__u32 flags = 0;
   1123	loff_t isize;
   1124	sector_t blkoff, end_blkoff;
   1125	sector_t delalloc_blkoff;
   1126	unsigned long delalloc_blklen;
   1127	unsigned int blkbits = inode->i_blkbits;
   1128	int ret, n;
   1129
   1130	ret = fiemap_prep(inode, fieinfo, start, &len, 0);
   1131	if (ret)
   1132		return ret;
   1133
   1134	inode_lock(inode);
   1135
   1136	isize = i_size_read(inode);
   1137
   1138	blkoff = start >> blkbits;
   1139	end_blkoff = (start + len - 1) >> blkbits;
   1140
   1141	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,
   1142							&delalloc_blkoff);
   1143
   1144	do {
   1145		__u64 blkphy;
   1146		unsigned int maxblocks;
   1147
   1148		if (delalloc_blklen && blkoff == delalloc_blkoff) {
   1149			if (size) {
   1150				/* End of the current extent */
   1151				ret = fiemap_fill_next_extent(
   1152					fieinfo, logical, phys, size, flags);
   1153				if (ret)
   1154					break;
   1155			}
   1156			if (blkoff > end_blkoff)
   1157				break;
   1158
   1159			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;
   1160			logical = blkoff << blkbits;
   1161			phys = 0;
   1162			size = delalloc_blklen << blkbits;
   1163
   1164			blkoff = delalloc_blkoff + delalloc_blklen;
   1165			delalloc_blklen = nilfs_find_uncommitted_extent(
   1166				inode, blkoff, &delalloc_blkoff);
   1167			continue;
   1168		}
   1169
   1170		/*
   1171		 * Limit the number of blocks that we look up so as
   1172		 * not to get into the next delayed allocation extent.
   1173		 */
   1174		maxblocks = INT_MAX;
   1175		if (delalloc_blklen)
   1176			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,
   1177					  maxblocks);
   1178		blkphy = 0;
   1179
   1180		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
   1181		n = nilfs_bmap_lookup_contig(
   1182			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);
   1183		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
   1184
   1185		if (n < 0) {
   1186			int past_eof;
   1187
   1188			if (unlikely(n != -ENOENT))
   1189				break; /* error */
   1190
   1191			/* HOLE */
   1192			blkoff++;
   1193			past_eof = ((blkoff << blkbits) >= isize);
   1194
   1195			if (size) {
   1196				/* End of the current extent */
   1197
   1198				if (past_eof)
   1199					flags |= FIEMAP_EXTENT_LAST;
   1200
   1201				ret = fiemap_fill_next_extent(
   1202					fieinfo, logical, phys, size, flags);
   1203				if (ret)
   1204					break;
   1205				size = 0;
   1206			}
   1207			if (blkoff > end_blkoff || past_eof)
   1208				break;
   1209		} else {
   1210			if (size) {
   1211				if (phys && blkphy << blkbits == phys + size) {
   1212					/* The current extent goes on */
   1213					size += n << blkbits;
   1214				} else {
   1215					/* Terminate the current extent */
   1216					ret = fiemap_fill_next_extent(
   1217						fieinfo, logical, phys, size,
   1218						flags);
   1219					if (ret || blkoff > end_blkoff)
   1220						break;
   1221
   1222					/* Start another extent */
   1223					flags = FIEMAP_EXTENT_MERGED;
   1224					logical = blkoff << blkbits;
   1225					phys = blkphy << blkbits;
   1226					size = n << blkbits;
   1227				}
   1228			} else {
   1229				/* Start a new extent */
   1230				flags = FIEMAP_EXTENT_MERGED;
   1231				logical = blkoff << blkbits;
   1232				phys = blkphy << blkbits;
   1233				size = n << blkbits;
   1234			}
   1235			blkoff += n;
   1236		}
   1237		cond_resched();
   1238	} while (true);
   1239
   1240	/* If ret is 1 then we just hit the end of the extent array */
   1241	if (ret == 1)
   1242		ret = 0;
   1243
   1244	inode_unlock(inode);
   1245	return ret;
   1246}