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Message-ID: <288f07e3573e1dd242a892a6aeef211cda68bc61.camel@dubeyko.com>
Subject: Re: [PATCH v6 03/13] exfat: add inode operations
From:   Vyacheslav Dubeyko <slava@dubeyko.com>
To:     Namjae Jeon <namjae.jeon@samsung.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc:     gregkh@linuxfoundation.org, valdis.kletnieks@vt.edu, hch@lst.de,
        sj1557.seo@samsung.com
Date:   Mon, 09 Dec 2019 12:54:32 +0300
In-Reply-To: <20191209065149.2230-4-namjae.jeon@samsung.com>
References: <20191209065149.2230-1-namjae.jeon@samsung.com>
         <CGME20191209065459epcas1p3349caea59da1b9b458a73923d724ca35@epcas1p3.samsung.com>
         <20191209065149.2230-4-namjae.jeon@samsung.com>
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Sender: linux-kernel-owner@vger.kernel.org
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On Mon, 2019-12-09 at 01:51 -0500, Namjae Jeon wrote:
> This adds the implementation of inode operations for exfat.
> 
> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
> ---
>  fs/exfat/inode.c |  693 ++++++++++++++++++++++
>  fs/exfat/namei.c | 1459
> ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 2152 insertions(+)
>  create mode 100644 fs/exfat/inode.c
>  create mode 100644 fs/exfat/namei.c
> 
> diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
> new file mode 100644
> index 000000000000..e1e20e74c92a
> --- /dev/null
> +++ b/fs/exfat/inode.c
> @@ -0,0 +1,693 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/buffer_head.h>
> +#include <linux/mpage.h>
> +#include <linux/bio.h>
> +#include <linux/blkdev.h>
> +#include <linux/time.h>
> +#include <linux/writeback.h>
> +#include <linux/uio.h>
> +#include <linux/random.h>
> +#include <linux/iversion.h>
> +
> +#include "exfat_raw.h"
> +#include "exfat_fs.h"
> +
> +/* 2-level option flag */
> +enum {
> +	BMAP_NOT_CREATE,
> +	BMAP_ADD_CLUSTER,
> +};
> +
> +static int __exfat_write_inode(struct inode *inode, int sync)
> +{
> +	int ret = -EIO;
> +	unsigned long long on_disk_size;
> +	struct exfat_timestamp tm;
> +	struct exfat_dentry *ep, *ep2;
> +	struct exfat_entry_set_cache *es = NULL;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	unsigned char is_dir = (ei->type == TYPE_DIR) ? 1 : 0;

The unsigned char type instead of boolean one? What's the point?


> +	struct exfat_dir_entry info;
> +
> +	if (inode->i_ino == EXFAT_ROOT_INO)
> +		return 0;
> +
> +	info.attr = exfat_make_attr(inode);
> +	info.size = i_size_read(inode);
> +
> +	exfat_time_unix2fat(sbi, &inode->i_mtime,
> &info.modify_timestamp);
> +	exfat_time_unix2fat(sbi, &inode->i_ctime,
> &info.create_timestamp);
> +	exfat_time_unix2fat(sbi, &inode->i_atime,
> &info.access_timestamp);
> +
> +	/*
> +	 * If the indode is already unlinked, there is no need for
> updating it.
> +	 */
> +	if (ei->dir.dir == DIR_DELETED)
> +		return 0;
> +
> +	if (is_dir && ei->dir.dir == sbi->root_dir && ei->entry == -1)
> +		return 0;
> +
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +
> +	/* get the directory entry of given file or directory */
> +	es = exfat_get_dentry_set(sb, &(ei->dir), ei->entry,
> ES_ALL_ENTRIES,
> +		&ep);
> +	if (!es)
> +		return -EIO;
> +	ep2 = ep + 1;

What if the ep points out on the latest item in the sequence? It looks
like that ep2 could point out on the garbage.

> +
> +	ep->file_attr = cpu_to_le16(info.attr);
> +
> +	/* set FILE_INFO structure using the acquired struct
> exfat_dentry */
> +	tm.sec  = info.create_timestamp.second;
> +	tm.min  = info.create_timestamp.minute;
> +	tm.hour = info.create_timestamp.hour;
> +	tm.day  = info.create_timestamp.day;
> +	tm.mon  = info.create_timestamp.month;
> +	tm.year = info.create_timestamp.year;
> +	exfat_set_entry_time(ep, &tm, TM_CREATE);
> +
> +	tm.sec  = info.modify_timestamp.second;
> +	tm.min  = info.modify_timestamp.minute;
> +	tm.hour = info.modify_timestamp.hour;
> +	tm.day  = info.modify_timestamp.day;
> +	tm.mon  = info.modify_timestamp.month;
> +	tm.year = info.modify_timestamp.year;
> +	exfat_set_entry_time(ep, &tm, TM_MODIFY);
> +
> +	/* File size should be zero if there is no cluster allocated */
> +	on_disk_size = info.size;
> +
> +	if (ei->start_clu == EOF_CLUSTER)
> +		on_disk_size = 0;
> +
> +	ep2->stream_valid_size = cpu_to_le64(on_disk_size);
> +	ep2->stream_size = ep2->stream_valid_size;
> +
> +	ret = exfat_update_dir_chksum_with_entry_set(sb, es, sync);
> +	kfree(es);

The exfat_get_dentry_set() allocates the es by kmalloc? Am I correct?


> +	return ret;
> +}
> +
> +int exfat_write_inode(struct inode *inode, struct writeback_control
> *wbc)
> +{
> +	int ret;
> +
> +	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
> +	ret = __exfat_write_inode(inode, wbc->sync_mode ==
> WB_SYNC_ALL);
> +	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
> +
> +	return ret;
> +}
> +
> +void exfat_sync_inode(struct inode *inode)
> +{
> +	lockdep_assert_held(&EXFAT_SB(inode->i_sb)->s_lock);
> +	__exfat_write_inode(inode, 1);
> +}
> +
> +/*
> + * Input: inode, (logical) clu_offset, target allocation area
> + * Output: errcode, cluster number
> + * *clu = (~0), if it's unable to allocate a new cluster
> + */
> +static int exfat_map_cluster(struct inode *inode, unsigned int
> clu_offset,
> +		unsigned int *clu, int create)
> +{
> +	int ret, modified = false;
> +	unsigned int last_clu;
> +	struct exfat_chain new_clu;
> +	struct exfat_dentry *ep;
> +	struct exfat_entry_set_cache *es = NULL;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	unsigned int local_clu_offset = clu_offset;
> +	unsigned int num_to_be_allocated = 0, num_clusters = 0;
> +
> +	ei->rwoffset = EXFAT_CLU_TO_B(clu_offset, sbi);
> +
> +	if (EXFAT_I(inode)->i_size_ondisk > 0)
> +		num_clusters =
> +			EXFAT_B_TO_CLU_ROUND_UP(EXFAT_I(inode)-
> >i_size_ondisk,
> +			sbi);
> +
> +	if (clu_offset >= num_clusters)
> +		num_to_be_allocated = clu_offset - num_clusters + 1;
> +
> +	if (!create && (num_to_be_allocated > 0)) {
> +		*clu = EOF_CLUSTER;
> +		return 0;
> +	}
> +
> +	*clu = last_clu = ei->start_clu;
> +
> +	if (ei->flags == ALLOC_NO_FAT_CHAIN) {
> +		if (clu_offset > 0 && *clu != EOF_CLUSTER) {
> +			last_clu += clu_offset - 1;
> +
> +			if (clu_offset == num_clusters)
> +				*clu = EOF_CLUSTER;
> +			else
> +				*clu += clu_offset;
> +		}
> +	} else if (ei->type == TYPE_FILE) {
> +		unsigned int fclus = 0;
> +		int err = exfat_get_cluster(inode, clu_offset,
> +				&fclus, clu, &last_clu, 1);
> +		if (err)
> +			return -EIO;
> +
> +		clu_offset -= fclus;
> +	} else {
> +		/* hint information */
> +		if (clu_offset > 0 && ei->hint_bmap.off != EOF_CLUSTER
> &&
> +		    ei->hint_bmap.off > 0 && clu_offset >= ei-
> >hint_bmap.off) {
> +			clu_offset -= ei->hint_bmap.off;
> +			/* hint_bmap.clu should be valid */
> +			WARN_ON(ei->hint_bmap.clu < 2);
> +			*clu = ei->hint_bmap.clu;
> +		}
> +
> +		while (clu_offset > 0 && *clu != EOF_CLUSTER) {
> +			last_clu = *clu;
> +			if (exfat_get_next_cluster(sb, clu))
> +				return -EIO;
> +			clu_offset--;
> +		}
> +	}
> +
> +	if (*clu == EOF_CLUSTER) {
> +		exfat_set_vol_flags(sb, VOL_DIRTY);
> +
> +		new_clu.dir = (last_clu == EOF_CLUSTER) ?
> +				EOF_CLUSTER : last_clu + 1;
> +		new_clu.size = 0;
> +		new_clu.flags = ei->flags;
> +
> +		/* allocate a cluster */
> +		if (num_to_be_allocated < 1) {
> +			/* Broken FAT (i_sze > allocated FAT) */
> +			exfat_fs_error(sb, "broken FAT chain.");
> +			return -EIO;
> +		}
> +
> +		ret = exfat_alloc_cluster(inode, num_to_be_allocated,
> &new_clu);
> +		if (ret)
> +			return ret;
> +
> +		if (new_clu.dir == EOF_CLUSTER || new_clu.dir ==
> FREE_CLUSTER) {
> +			exfat_fs_error(sb,
> +				"bogus cluster new allocated (last_clu
> : %u, new_clu : %u)",
> +				last_clu, new_clu.dir);
> +			return -EIO;
> +		}
> +
> +		/* append to the FAT chain */
> +		if (last_clu == EOF_CLUSTER) {
> +			if (new_clu.flags == ALLOC_FAT_CHAIN)
> +				ei->flags = ALLOC_FAT_CHAIN;
> +			ei->start_clu = new_clu.dir;
> +			modified = true;
> +		} else {
> +			if (new_clu.flags != ei->flags) {
> +				/* no-fat-chain bit is disabled,
> +				 * so fat-chain should be synced with
> +				 * alloc-bitmap
> +				 */
> +				exfat_chain_cont_cluster(sb, ei-
> >start_clu,
> +					num_clusters);
> +				ei->flags = ALLOC_FAT_CHAIN;
> +				modified = true;
> +			}
> +			if (new_clu.flags == ALLOC_FAT_CHAIN)
> +				if (exfat_ent_set(sb, last_clu,
> new_clu.dir))
> +					return -EIO;
> +		}
> +
> +		num_clusters += num_to_be_allocated;
> +		*clu = new_clu.dir;
> +
> +		if (ei->dir.dir != DIR_DELETED) {
> +			es = exfat_get_dentry_set(sb, &(ei->dir), ei-
> >entry,
> +				ES_ALL_ENTRIES, &ep);
> +			if (!es)
> +				return -EIO;
> +			/* get stream entry */
> +			ep++;
> +
> +			/* update directory entry */
> +			if (modified) {
> +				if (ep->stream_flags != ei->flags)
> +					ep->stream_flags = ei->flags;
> +
> +				if (le32_to_cpu(ep->stream_start_clu)
> !=
> +						ei->start_clu)
> +					ep->stream_start_clu =
> +						cpu_to_le32(ei-
> >start_clu);
> +
> +				ep->stream_valid_size =
> +					cpu_to_le64(i_size_read(inode))
> ;
> +				ep->stream_size = ep-
> >stream_valid_size;
> +			}
> +
> +			if (exfat_update_dir_chksum_with_entry_set(sb,
> es,
> +			    inode_needs_sync(inode)))
> +				return -EIO;
> +			kfree(es);
> +
> +		} /* end of if != DIR_DELETED */
> +
> +		inode->i_blocks +=
> +			num_to_be_allocated << sbi->sect_per_clus_bits;
> +
> +		/*
> +		 * Move *clu pointer along FAT chains (hole care)
> because the
> +		 * caller of this function expect *clu to be the last
> cluster.
> +		 * This only works when num_to_be_allocated >= 2,
> +		 * *clu = (the first cluster of the allocated chain) =>
> +		 * (the last cluster of ...)
> +		 */
> +		if (ei->flags == ALLOC_NO_FAT_CHAIN) {
> +			*clu += num_to_be_allocated - 1;
> +		} else {
> +			while (num_to_be_allocated > 1) {
> +				if (exfat_get_next_cluster(sb, clu))
> +					return -EIO;
> +				num_to_be_allocated--;
> +			}
> +		}
> +
> +	}
> +
> +	/* hint information */
> +	ei->hint_bmap.off = local_clu_offset;
> +	ei->hint_bmap.clu = *clu;
> +
> +	return 0;
> +}
> +
> +static int exfat_bmap(struct inode *inode, sector_t sector, sector_t
> *phys,
> +		unsigned long *mapped_blocks, int *create)
> +{
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	sector_t last_block;
> +	unsigned int cluster, clu_offset, sec_offset;
> +	int err = 0;
> +
> +	*phys = 0;
> +	*mapped_blocks = 0;
> +
> +	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);
> +	if (sector >= last_block && *create == BMAP_NOT_CREATE)
> +		return 0;
> +
> +	/* Is this block already allocated? */
> +	clu_offset = sector >> sbi->sect_per_clus_bits;  /* cluster
> offset */
> +
> +	err = exfat_map_cluster(inode, clu_offset, &cluster,
> +		*create & BMAP_ADD_CLUSTER);
> +	if (err) {
> +		if (err != -ENOSPC)
> +			return -EIO;
> +		return err;
> +	}
> +
> +	if (cluster != EOF_CLUSTER) {
> +		/* sector offset in cluster */
> +		sec_offset = sector & (sbi->sect_per_clus - 1);
> +
> +		*phys = exfat_cluster_to_sector(sbi, cluster) +
> sec_offset;
> +		*mapped_blocks = sbi->sect_per_clus - sec_offset;
> +	}
> +
> +	if (sector < last_block)
> +		*create = BMAP_NOT_CREATE;
> +	return 0;
> +}
> +
> +static int exfat_get_block(struct inode *inode, sector_t iblock,
> +		struct buffer_head *bh_result, int create)
> +{
> +	struct super_block *sb = inode->i_sb;
> +	unsigned long max_blocks = bh_result->b_size >> inode-
> >i_blkbits;
> +	int err = 0;
> +	unsigned long mapped_blocks;
> +	sector_t phys;
> +	loff_t pos;
> +	int bmap_create = create ? BMAP_ADD_CLUSTER : BMAP_NOT_CREATE;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	err = exfat_bmap(inode, iblock, &phys, &mapped_blocks,
> &bmap_create);
> +	if (err) {
> +		if (err != -ENOSPC)
> +			exfat_fs_error_ratelimit(sb,
> +				"failed to bmap (inode : %p iblock :
> %llu, err : %d)",
> +				inode, (unsigned long long)iblock,
> err);
> +		goto unlock_ret;
> +	}
> +
> +	if (phys) {
> +		max_blocks = min(mapped_blocks, max_blocks);
> +
> +		/* Treat newly added block / cluster */
> +		if (bmap_create || buffer_delay(bh_result)) {
> +			/* Update i_size_ondisk */
> +			pos = EXFAT_BLK_TO_B((iblock + 1), sb);
> +			if (EXFAT_I(inode)->i_size_ondisk < pos)
> +				EXFAT_I(inode)->i_size_ondisk = pos;
> +
> +			if (bmap_create) {
> +				if (buffer_delay(bh_result) &&
> +				    pos > EXFAT_I(inode)-
> >i_size_aligned) {
> +					exfat_fs_error(sb,
> +						"requested for bmap out
> of range(pos : (%llu) > i_size_aligned(%llu)\n",
> +						pos,
> +						EXFAT_I(inode)-
> >i_size_aligned);
> +					err = -EIO;
> +					goto unlock_ret;
> +				}
> +				set_buffer_new(bh_result);
> +
> +				/*
> +				 * adjust i_size_aligned if
> i_size_ondisk is
> +				 * bigger than it. (i.e. non-DA)
> +				 */
> +				if (EXFAT_I(inode)->i_size_ondisk >
> +				    EXFAT_I(inode)->i_size_aligned) {
> +					EXFAT_I(inode)->i_size_aligned
> =
> +						EXFAT_I(inode)-
> >i_size_ondisk;
> +				}
> +			}
> +
> +			if (buffer_delay(bh_result))
> +				clear_buffer_delay(bh_result);
> +		}
> +		map_bh(bh_result, sb, phys);
> +	}
> +
> +	bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);
> +unlock_ret:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return err;
> +}
> +
> +static int exfat_readpage(struct file *file, struct page *page)
> +{
> +	return mpage_readpage(page, exfat_get_block);
> +}
> +
> +static int exfat_readpages(struct file *file, struct address_space
> *mapping,
> +		struct list_head *pages, unsigned int nr_pages)
> +{
> +	return mpage_readpages(mapping, pages, nr_pages,
> exfat_get_block);
> +}
> +
> +static int exfat_writepage(struct page *page, struct
> writeback_control *wbc)
> +{
> +	return block_write_full_page(page, exfat_get_block, wbc);
> +}
> +
> +static int exfat_writepages(struct address_space *mapping,
> +		struct writeback_control *wbc)
> +{
> +	return mpage_writepages(mapping, wbc, exfat_get_block);
> +}
> +
> +static void exfat_write_failed(struct address_space *mapping, loff_t
> to)
> +{
> +	struct inode *inode = mapping->host;
> +
> +	if (to > i_size_read(inode)) {
> +		truncate_pagecache(inode, i_size_read(inode));
> +		exfat_truncate(inode, EXFAT_I(inode)->i_size_aligned);
> +	}
> +}
> +
> +static int exfat_write_begin(struct file *file, struct address_space
> *mapping,
> +		loff_t pos, unsigned int len, unsigned int flags,
> +		struct page **pagep, void **fsdata)
> +{
> +	int ret;
> +
> +	*pagep = NULL;
> +	ret = cont_write_begin(file, mapping, pos, len, flags, pagep,
> fsdata,
> +			       exfat_get_block,
> +			       &EXFAT_I(mapping->host)->i_size_ondisk);
> +
> +	if (ret < 0)
> +		exfat_write_failed(mapping, pos+len);
> +
> +	return ret;
> +}
> +
> +static int exfat_write_end(struct file *file, struct address_space
> *mapping,
> +		loff_t pos, unsigned int len, unsigned int copied,
> +		struct page *pagep, void *fsdata)
> +{
> +	struct inode *inode = mapping->host;
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	int err;
> +
> +	err = generic_write_end(file, mapping, pos, len, copied, pagep,
> fsdata);
> +
> +	if (EXFAT_I(inode)->i_size_aligned < i_size_read(inode)) {
> +		exfat_fs_error(inode->i_sb,
> +			"invalid size(size(%llu) > aligned(%llu)\n",
> +			i_size_read(inode), EXFAT_I(inode)-
> >i_size_aligned);
> +		return -EIO;
> +	}
> +
> +	if (err < len)
> +		exfat_write_failed(mapping, pos+len);
> +
> +	if (!(err < 0) && !(ei->attr & ATTR_ARCHIVE)) {
> +		inode->i_mtime = inode->i_ctime = current_time(inode);
> +		ei->attr |= ATTR_ARCHIVE;
> +		mark_inode_dirty(inode);
> +	}
> +
> +	return err;
> +}
> +
> +static ssize_t exfat_direct_IO(struct kiocb *iocb, struct iov_iter
> *iter)
> +{
> +	struct address_space *mapping = iocb->ki_filp->f_mapping;
> +	struct inode *inode = mapping->host;
> +	loff_t size = iocb->ki_pos + iov_iter_count(iter);
> +	int rw = iov_iter_rw(iter);
> +	ssize_t ret;
> +
> +	if (rw == WRITE) {
> +		/*
> +		 * FIXME: blockdev_direct_IO() doesn't use
> ->write_begin(),
> +		 * so we need to update the ->i_size_aligned to block
> boundary.
> +		 *
> +		 * But we must fill the remaining area or hole by nul
> for
> +		 * updating ->i_size_aligned
> +		 *
> +		 * Return 0, and fallback to normal buffered write.
> +		 */
> +		if (EXFAT_I(inode)->i_size_aligned < size)
> +			return 0;
> +	}
> +
> +	/*
> +	 * Need to use the DIO_LOCKING for avoiding the race
> +	 * condition of exfat_get_block() and ->truncate().
> +	 */
> +	ret = blockdev_direct_IO(iocb, inode, iter, exfat_get_block);
> +	if (ret < 0 && (rw & WRITE))
> +		exfat_write_failed(mapping, size);
> +	return ret;
> +}
> +
> +static sector_t exfat_aop_bmap(struct address_space *mapping,
> sector_t block)
> +{
> +	sector_t blocknr;
> +
> +	/* exfat_get_cluster() assumes the requested blocknr isn't
> truncated. */
> +	down_read(&EXFAT_I(mapping->host)->truncate_lock);
> +	blocknr = generic_block_bmap(mapping, block, exfat_get_block);
> +	up_read(&EXFAT_I(mapping->host)->truncate_lock);
> +	return blocknr;
> +}
> +
> +static const struct address_space_operations exfat_aops = {
> +	.readpage	= exfat_readpage,
> +	.readpages	= exfat_readpages,
> +	.writepage	= exfat_writepage,
> +	.writepages	= exfat_writepages,
> +	.write_begin	= exfat_write_begin,
> +	.write_end	= exfat_write_end,
> +	.direct_IO	= exfat_direct_IO,
> +	.bmap		= exfat_aop_bmap
> +};
> +
> +static inline unsigned long exfat_hash(loff_t i_pos)
> +{
> +	return hash_32(i_pos, EXFAT_HASH_BITS);
> +}
> +
> +void exfat_hash_inode(struct inode *inode, loff_t i_pos)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
> +	struct hlist_head *head = sbi->inode_hashtable +
> exfat_hash(i_pos);
> +
> +	spin_lock(&sbi->inode_hash_lock);
> +	EXFAT_I(inode)->i_pos = i_pos;
> +	hlist_add_head(&EXFAT_I(inode)->i_hash_fat, head);
> +	spin_unlock(&sbi->inode_hash_lock);
> +}
> +
> +void exfat_unhash_inode(struct inode *inode)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
> +
> +	spin_lock(&sbi->inode_hash_lock);
> +	hlist_del_init(&EXFAT_I(inode)->i_hash_fat);
> +	EXFAT_I(inode)->i_pos = 0;
> +	spin_unlock(&sbi->inode_hash_lock);
> +}
> +
> +struct inode *exfat_iget(struct super_block *sb, loff_t i_pos)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *info;
> +	struct hlist_head *head = sbi->inode_hashtable +
> exfat_hash(i_pos);
> +	struct inode *inode = NULL;
> +
> +	spin_lock(&sbi->inode_hash_lock);
> +	hlist_for_each_entry(info, head, i_hash_fat) {
> +		WARN_ON(info->vfs_inode.i_sb != sb);
> +
> +		if (i_pos != info->i_pos)
> +			continue;
> +		inode = igrab(&info->vfs_inode);
> +		if (inode)
> +			break;
> +	}
> +	spin_unlock(&sbi->inode_hash_lock);
> +	return inode;
> +}
> +
> +/* doesn't deal with root inode */
> +static int exfat_fill_inode(struct inode *inode, struct
> exfat_dir_entry *info)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	loff_t size = info->size;
> +
> +	memcpy(&ei->dir, &info->dir, sizeof(struct exfat_chain));
> +	ei->entry = info->entry;
> +	ei->attr = info->attr;
> +	ei->start_clu = info->start_clu;
> +	ei->flags = info->flags;
> +	ei->type = info->type;
> +
> +	ei->version = 0;
> +	ei->hint_stat.eidx = 0;
> +	ei->hint_stat.clu = info->start_clu;
> +	ei->hint_femp.eidx = EXFAT_HINT_NONE;
> +	ei->rwoffset = 0;
> +	ei->hint_bmap.off = EOF_CLUSTER;
> +	ei->i_pos = 0;
> +
> +	inode->i_uid = sbi->options.fs_uid;
> +	inode->i_gid = sbi->options.fs_gid;
> +	inode_inc_iversion(inode);
> +	inode->i_generation = prandom_u32();
> +
> +	if (info->attr & ATTR_SUBDIR) { /* directory */
> +		inode->i_generation &= ~1;
> +		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);

What's about constants instead of 0777 here? By the way, are you sure
that it's proper permissions set?

> +		inode->i_op = &exfat_dir_inode_operations;
> +		inode->i_fop = &exfat_dir_operations;
> +		set_nlink(inode, info->num_subdirs);
> +	} else { /* regular file */
> +		inode->i_generation |= 1;
> +		inode->i_mode = exfat_make_mode(sbi, info->attr, 0777);

What's about constants instead of 0777 here? By the way, are you sure
that it's proper permissions set?


> +		inode->i_op = &exfat_file_inode_operations;
> +		inode->i_fop = &exfat_file_operations;
> +		inode->i_mapping->a_ops = &exfat_aops;
> +		inode->i_mapping->nrpages = 0;
> +	}
> +
> +	i_size_write(inode, size);
> +
> +	/* ondisk and aligned size should be aligned with block size */
> +	if (size & (inode->i_sb->s_blocksize - 1)) {
> +		size |= (inode->i_sb->s_blocksize - 1);
> +		size++;
> +	}
> +
> +	ei->i_size_aligned = size;
> +	ei->i_size_ondisk = size;
> +
> +	exfat_save_attr(inode, info->attr);
> +
> +	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size -
> 1)) &
> +		~(sbi->cluster_size - 1)) >> inode->i_blkbits;
> +
> +	exfat_time_fat2unix(sbi, &inode->i_mtime, &info-
> >modify_timestamp);
> +	exfat_time_fat2unix(sbi, &inode->i_ctime, &info-
> >create_timestamp);
> +	exfat_time_fat2unix(sbi, &inode->i_atime, &info-
> >access_timestamp);
> +
> +	exfat_cache_init_inode(inode);
> +
> +	return 0;
> +}
> +
> +struct inode *exfat_build_inode(struct super_block *sb,
> +		struct exfat_dir_entry *info, loff_t i_pos)
> +{
> +	struct inode *inode;
> +	int err;
> +
> +	inode = exfat_iget(sb, i_pos);
> +	if (inode)
> +		goto out;
> +	inode = new_inode(sb);
> +	if (!inode) {
> +		inode = ERR_PTR(-ENOMEM);
> +		goto out;
> +	}
> +	inode->i_ino = iunique(sb, EXFAT_ROOT_INO);
> +	inode_set_iversion(inode, 1);
> +	err = exfat_fill_inode(inode, info);
> +	if (err) {
> +		iput(inode);
> +		inode = ERR_PTR(err);
> +		goto out;
> +	}
> +	exfat_hash_inode(inode, i_pos);
> +	insert_inode_hash(inode);
> +out:
> +	return inode;
> +}
> +
> +void exfat_evict_inode(struct inode *inode)
> +{
> +	truncate_inode_pages(&inode->i_data, 0);
> +
> +	if (!inode->i_nlink) {
> +		i_size_write(inode, 0);
> +		mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
> +		__exfat_truncate(inode, 0);
> +		mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
> +	}
> +
> +	invalidate_inode_buffers(inode);
> +	clear_inode(inode);
> +	exfat_cache_inval_inode(inode);
> +	exfat_unhash_inode(inode);
> +}
> diff --git a/fs/exfat/namei.c b/fs/exfat/namei.c
> new file mode 100644
> index 000000000000..120a50fc494a
> --- /dev/null
> +++ b/fs/exfat/namei.c
> @@ -0,0 +1,1459 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
> + */
> +
> +#include <linux/iversion.h>
> +#include <linux/namei.h>
> +#include <linux/slab.h>
> +#include <linux/buffer_head.h>
> +#include <linux/nls.h>
> +
> +#include "exfat_raw.h"
> +#include "exfat_fs.h"
> +
> +static inline unsigned long exfat_d_version(struct dentry *dentry)
> +{
> +	return (unsigned long) dentry->d_fsdata;
> +}
> +
> +static inline void exfat_d_version_set(struct dentry *dentry,
> +		unsigned long version)
> +{
> +	dentry->d_fsdata = (void *) version;
> +}
> +
> +/*
> + * If new entry was created in the parent, it could create the 8.3
> + * alias (the shortname of logname).  So, the parent may have the
> + * negative-dentry which matches the created 8.3 alias.
> + *
> + * If it happened, the negative dentry isn't actually negative
> + * anymore.  So, drop it.
> + */
> +static int __exfat_revalidate_common(struct dentry *dentry)
> +{
> +	int ret = 1;
> +
> +	spin_lock(&dentry->d_lock);
> +	if (!inode_eq_iversion(d_inode(dentry->d_parent),
> +			exfat_d_version(dentry)))
> +		ret = 0;
> +	spin_unlock(&dentry->d_lock);
> +	return ret;
> +}
> +
> +static int __exfat_revalidate(struct dentry *dentry)
> +{
> +	/* This is not negative dentry. Always valid. */
> +	if (d_really_is_positive(dentry))
> +		return 1;
> +	return __exfat_revalidate_common(dentry);
> +}
> +
> +static int __exfat_revalidate_ci(struct dentry *dentry, unsigned int
> flags)
> +{
> +	/*
> +	 * This is not negative dentry. Always valid.
> +	 *
> +	 * Note, rename() to existing directory entry will have
> ->d_inode,
> +	 * and will use existing name which isn't specified name by
> user.
> +	 *
> +	 * We may be able to drop this positive dentry here. But
> dropping
> +	 * positive dentry isn't good idea. So it's unsupported like
> +	 * rename("filename", "FILENAME") for now.
> +	 */
> +	if (d_really_is_positive(dentry))
> +		return 1;
> +	/*
> +	 * Drop the negative dentry, in order to make sure to use the
> +	 * case sensitive name which is specified by user if this is
> +	 * for creation.
> +	 */
> +	if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
> +		return 0;
> +	return __exfat_revalidate_common(dentry);
> +}
> +
> +
> +/* returns the length of a struct qstr, ignoring trailing dots */
> +static unsigned int __exfat_striptail_len(unsigned int len, const
> char *name)
> +{
> +	while (len && name[len - 1] == '.')
> +		len--;
> +	return len;
> +}
> +
> +static unsigned int exfat_striptail_len(const struct qstr *qstr)
> +{
> +	return __exfat_striptail_len(qstr->len, qstr->name);
> +}
> +
> +static inline unsigned int __exfat_full_name_hash(const struct
> dentry *dentry,
> +		const char *name, unsigned int len)
> +{
> +	return full_name_hash(dentry, name, len);
> +}
> +
> +static inline unsigned long __exfat_init_name_hash(const struct
> dentry *dentry)
> +{
> +	return init_name_hash(dentry);
> +}
> +
> +/*
> + * Compute the hash for the exfat name corresponding to the dentry.
> + * Note: if the name is invalid, we leave the hash code unchanged so
> + * that the existing dentry can be used. The exfat fs routines will
> + * return ENOENT or EINVAL as appropriate.
> + */
> +static int exfat_d_hash(const struct dentry *dentry, struct qstr
> *qstr)
> +{
> +	unsigned int len = exfat_striptail_len(qstr);
> +
> +	qstr->hash = __exfat_full_name_hash(dentry, qstr->name, len);
> +	return 0;
> +}
> +
> +/*
> + * Compute the hash for the exfat name corresponding to the dentry.
> + * Note: if the name is invalid, we leave the hash code unchanged so
> + * that the existing dentry can be used. The exfat fs routines will
> + * return ENOENT or EINVAL as appropriate.
> + */
> +static int exfat_d_hashi(const struct dentry *dentry, struct qstr
> *qstr)
> +{
> +	struct nls_table *t = EXFAT_SB(dentry->d_sb)->nls_io;
> +	const unsigned char *name;
> +	unsigned int len;
> +	unsigned long hash;
> +
> +	name = qstr->name;
> +	len = exfat_striptail_len(qstr);
> +
> +	hash = __exfat_init_name_hash(dentry);
> +	while (len--)
> +		hash = partial_name_hash(nls_tolower(t, *name++),
> hash);
> +	qstr->hash = end_name_hash(hash);
> +
> +	return 0;
> +}
> +
> +/*
> + * Case sensitive compare of two exfat names.
> + */
> +static int exfat_cmp(const struct dentry *dentry, unsigned int len,
> +		const char *str, const struct qstr *name)
> +{
> +	unsigned int alen, blen;
> +
> +	/* A filename cannot end in '.' or we treat it like it has none
> */
> +	alen = exfat_striptail_len(name);
> +	blen = __exfat_striptail_len(len, str);
> +	if (alen == blen) {
> +		if (strncmp(name->name, str, alen) == 0)
> +			return 0;
> +	}
> +	return 1;
> +}
> +
> +/*
> + * Case insensitive compare of two exfat names.
> + */
> +static int exfat_cmpi(const struct dentry *dentry, unsigned int len,
> +		const char *str, const struct qstr *name)
> +{
> +	struct nls_table *t = EXFAT_SB(dentry->d_sb)->nls_io;
> +	unsigned int alen, blen;
> +
> +	/* A filename cannot end in '.' or we treat it like it has none
> */
> +	alen = exfat_striptail_len(name);
> +	blen = __exfat_striptail_len(len, str);
> +	if (alen == blen) {
> +		if (nls_strnicmp(t, name->name, str, alen) == 0)
> +			return 0;
> +	}
> +	return 1;
> +}
> +
> +static int exfat_revalidate(struct dentry *dentry, unsigned int
> flags)
> +{
> +	if (flags & LOOKUP_RCU)
> +		return -ECHILD;
> +
> +	return __exfat_revalidate(dentry);
> +}
> +
> +static int exfat_revalidate_ci(struct dentry *dentry, unsigned int
> flags)
> +{
> +	if (flags & LOOKUP_RCU)
> +		return -ECHILD;
> +
> +	return __exfat_revalidate_ci(dentry, flags);
> +}
> +
> +const struct dentry_operations exfat_dentry_ops = {
> +	.d_revalidate	= exfat_revalidate,
> +	.d_hash		= exfat_d_hash,
> +	.d_compare	= exfat_cmp,
> +};
> +
> +const struct dentry_operations exfat_ci_dentry_ops = {
> +	.d_revalidate	= exfat_revalidate_ci,
> +	.d_hash		= exfat_d_hashi,
> +	.d_compare	= exfat_cmpi,
> +};
> +
> +/* used only in search empty_slot() */
> +#define CNT_UNUSED_NOHIT        (-1)
> +#define CNT_UNUSED_HIT          (-2)
> +/* search EMPTY CONTINUOUS "num_entries" entries */
> +static int exfat_search_empty_slot(struct super_block *sb,
> +		struct exfat_hint_femp *hint_femp, struct exfat_chain
> *p_dir,
> +		int num_entries)
> +{
> +	int i, dentry, num_empty = 0;
> +	int dentries_per_clu;
> +	unsigned int type;
> +	struct exfat_chain clu;
> +	struct exfat_dentry *ep;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct buffer_head *bh;
> +
> +	dentries_per_clu = sbi->dentries_per_clu;
> +
> +	if (hint_femp->eidx != EXFAT_HINT_NONE) {
> +		dentry = hint_femp->eidx;
> +		if (num_entries <= hint_femp->count) {
> +			hint_femp->eidx = EXFAT_HINT_NONE;
> +			return dentry;
> +		}
> +
> +		exfat_chain_dup(&clu, &hint_femp->cur);
> +	} else {
> +		exfat_chain_dup(&clu, p_dir);
> +		dentry = 0;
> +	}
> +
> +	while (clu.dir != EOF_CLUSTER) {
> +		i = dentry & (dentries_per_clu - 1);
> +
> +		for (; i < dentries_per_clu; i++, dentry++) {
> +			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
> +			if (!ep)
> +				return -EIO;
> +			type = exfat_get_entry_type(ep);
> +			brelse(bh);
> +
> +			if (type == TYPE_UNUSED || type ==
> TYPE_DELETED) {
> +				num_empty++;
> +				if (hint_femp->eidx == EXFAT_HINT_NONE)
> {
> +					hint_femp->eidx = dentry;
> +					hint_femp->count =
> CNT_UNUSED_NOHIT;
> +					exfat_chain_set(&hint_femp-
> >cur,
> +						clu.dir, clu.size,
> clu.flags);
> +				}
> +
> +				if (type == TYPE_UNUSED &&
> +				    hint_femp->count != CNT_UNUSED_HIT)
> +					hint_femp->count =
> CNT_UNUSED_HIT;
> +			} else {
> +				if (hint_femp->eidx != EXFAT_HINT_NONE
> &&
> +				    hint_femp->count == CNT_UNUSED_HIT)
> {
> +					/* unused empty group means
> +					 * an empty group which
> includes
> +					 * unused dentry
> +					 */
> +					exfat_fs_error(sb,
> +						"found bogus dentry(%d)
> beyond unused empty group(%d) (start_clu : %u, cur_clu : %u)",
> +						dentry, hint_femp-
> >eidx,
> +						p_dir->dir, clu.dir);
> +					return -EIO;
> +				}
> +
> +				num_empty = 0;
> +				hint_femp->eidx = EXFAT_HINT_NONE;
> +			}
> +
> +			if (num_empty >= num_entries) {
> +				/* found and invalidate hint_femp */
> +				hint_femp->eidx = EXFAT_HINT_NONE;
> +				return (dentry - (num_entries - 1));
> +			}
> +		}
> +
> +		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
> +			if (--clu.size > 0)
> +				clu.dir++;
> +			else
> +				clu.dir = EOF_CLUSTER;
> +		} else {
> +			if (exfat_get_next_cluster(sb, &clu.dir))
> +				return -EIO;
> +		}
> +	}
> +
> +	return -ENOSPC;
> +}
> +
> +static int exfat_check_max_dentries(struct inode *inode)
> +{
> +	if (EXFAT_B_TO_DEN(i_size_read(inode)) >= MAX_EXFAT_DENTRIES) {
> +		/*
> +		 * exFAT spec allows a dir to grow upto 8388608(256MB)
> +		 * dentries
> +		 */
> +		return -ENOSPC;
> +	}
> +	return 0;
> +}
> +
> +/* find empty directory entry.
> + * if there isn't any empty slot, expand cluster chain.
> + */
> +int exfat_find_empty_entry(struct inode *inode, struct exfat_chain
> *p_dir,
> +		int num_entries)
> +{
> +	int dentry;
> +	unsigned int ret, last_clu;
> +	sector_t sector;
> +	loff_t size = 0;
> +	struct exfat_chain clu;
> +	struct exfat_dentry *ep = NULL;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	struct exfat_hint_femp hint_femp;
> +
> +	hint_femp.eidx = EXFAT_HINT_NONE;
> +
> +	if (ei->hint_femp.eidx != EXFAT_HINT_NONE) {
> +		memcpy(&hint_femp, &ei->hint_femp,
> +				sizeof(struct exfat_hint_femp));
> +		ei->hint_femp.eidx = EXFAT_HINT_NONE;
> +	}
> +
> +	while ((dentry = exfat_search_empty_slot(sb, &hint_femp, p_dir,
> +					num_entries)) < 0) {
> +		if (dentry == -EIO)
> +			break;
> +
> +		if (exfat_check_max_dentries(inode))
> +			return -ENOSPC;
> +
> +		/* we trust p_dir->size regardless of FAT type */
> +		if (exfat_find_last_cluster(sb, p_dir, &last_clu))
> +			return -EIO;
> +
> +		/*
> +		 * Allocate new cluster to this directory
> +		 */
> +		exfat_chain_set(&clu, last_clu + 1, 0, p_dir->flags);
> +
> +		/* allocate a cluster */
> +		ret = exfat_alloc_cluster(inode, 1, &clu);
> +		if (ret)
> +			return ret;
> +
> +		if (exfat_zeroed_cluster(inode, clu.dir))
> +			return -EIO;
> +
> +		/* append to the FAT chain */
> +		if (clu.flags != p_dir->flags) {
> +			/* no-fat-chain bit is disabled,
> +			 * so fat-chain should be synced with alloc-
> bitmap
> +			 */
> +			exfat_chain_cont_cluster(sb, p_dir->dir, p_dir-
> >size);
> +			p_dir->flags = ALLOC_FAT_CHAIN;
> +			hint_femp.cur.flags = ALLOC_FAT_CHAIN;
> +		}
> +
> +		if (clu.flags == ALLOC_FAT_CHAIN)
> +			if (exfat_ent_set(sb, last_clu, clu.dir))
> +				return -EIO;
> +
> +		if (hint_femp.eidx == EXFAT_HINT_NONE) {
> +			/* the special case that new dentry
> +			 * should be allocated from the start of new
> cluster
> +			 */
> +			hint_femp.eidx = EXFAT_B_TO_DEN_IDX(p_dir-
> >size, sbi);
> +			hint_femp.count = sbi->dentries_per_clu;
> +
> +			exfat_chain_set(&hint_femp.cur, clu.dir, 0,
> clu.flags);
> +		}
> +		hint_femp.cur.size++;
> +		p_dir->size++;
> +		size = EXFAT_CLU_TO_B(p_dir->size, sbi);
> +
> +		/* update the directory entry */
> +		if (p_dir->dir != sbi->root_dir) {
> +			struct buffer_head *bh;
> +
> +			ep = exfat_get_dentry(sb,
> +				&(ei->dir), ei->entry + 1, &bh,
> &sector);
> +			if (!ep)
> +				return -EIO;
> +
> +			ep->stream_valid_size = cpu_to_le64(size);
> +			ep->stream_size = ep->stream_valid_size;
> +			ep->stream_flags = p_dir->flags;
> +			exfat_update_bh(sb, bh, IS_DIRSYNC(inode));
> +			brelse(bh);
> +			if (update_dir_chksum(inode, &(ei->dir), ei-
> >entry))
> +				return -EIO;
> +		}
> +
> +		/* directory inode should be updated in here */
> +		i_size_write(inode, size);
> +		EXFAT_I(inode)->i_size_ondisk += sbi->cluster_size;
> +		EXFAT_I(inode)->i_size_aligned += sbi->cluster_size;
> +		EXFAT_I(inode)->flags = p_dir->flags;
> +		inode->i_blocks += 1 << sbi->sect_per_clus_bits;
> +	}
> +
> +	return dentry;
> +}
> +
> +/*
> + * Name Resolution Functions :
> + * Zero if it was successful; otherwise nonzero.
> + */
> +static int __exfat_resolve_path(struct inode *inode, const unsigned
> char *path,
> +		struct exfat_chain *p_dir, struct exfat_uni_name
> *p_uniname,
> +		int lookup)
> +{
> +	int namelen;
> +	int lossy = NLS_NAME_NO_LOSSY;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +
> +	/* DOT and DOTDOT are handled by VFS layer */
> +
> +	/* strip all trailing spaces */
> +	/* DO NOTHING : Is needed? */
> +
> +	/* strip all trailing periods */
> +	namelen = __exfat_striptail_len(strlen(path), path);
> +	if (!namelen)
> +		return -ENOENT;
> +
> +	/* the limitation of linux? */
> +	if (strlen(path) > (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
> +		return -ENAMETOOLONG;
> +
> +	/*
> +	 * strip all leading spaces :
> +	 * "MS windows 7" supports leading spaces.
> +	 * So we should skip this preprocessing for compatibility.
> +	 */
> +
> +	/* file name conversion :
> +	 * If lookup case, we allow bad-name for compatibility.
> +	 */
> +	namelen = exfat_nls_vfsname_to_uni16s(sb, path, namelen,
> p_uniname,
> +			&lossy);
> +	if (namelen < 0)
> +		return namelen; /* return error value */
> +
> +	if ((lossy && !lookup) || !namelen)
> +		return -EINVAL;
> +
> +	exfat_chain_set(p_dir, ei->start_clu,
> +		EXFAT_B_TO_CLU(i_size_read(inode), sbi), ei->flags);
> +
> +	return 0;
> +}
> +
> +static inline int exfat_resolve_path(struct inode *inode,
> +		const unsigned char *path, struct exfat_chain *dir,
> +		struct exfat_uni_name *uni)
> +{
> +	return __exfat_resolve_path(inode, path, dir, uni, 0);
> +}
> +
> +static inline int exfat_resolve_path_for_lookup(struct inode *inode,
> +		const unsigned char *path, struct exfat_chain *dir,
> +		struct exfat_uni_name *uni)
> +{
> +	return __exfat_resolve_path(inode, path, dir, uni, 1);
> +}
> +
> +static inline loff_t exfat_make_i_pos(struct exfat_dir_entry *info)
> +{
> +	return ((loff_t) info->dir.dir << 32) | (info->entry &
> 0xffffffff);
> +}
> +
> +static int exfat_add_entry(struct inode *inode, const char *path,
> +		struct exfat_chain *p_dir, unsigned int type,
> +		struct exfat_dir_entry *info)
> +{
> +	int ret, dentry, num_entries;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_uni_name uniname;
> +	struct exfat_chain clu;
> +	int clu_size = 0;
> +	unsigned int start_clu = FREE_CLUSTER;
> +
> +	ret = exfat_resolve_path(inode, path, p_dir, &uniname);
> +	if (ret)
> +		goto out;
> +
> +	num_entries = exfat_get_num_entries(&uniname);
> +	if (num_entries < 0) {
> +		ret = num_entries;
> +		goto out;
> +	}
> +
> +	/* exfat_find_empty_entry must be called before alloc_cluster()
> */
> +	dentry = exfat_find_empty_entry(inode, p_dir, num_entries);
> +	if (dentry < 0) {
> +		ret = dentry; /* -EIO or -ENOSPC */
> +		goto out;
> +	}
> +
> +	if (type == TYPE_DIR) {
> +		ret = exfat_alloc_new_dir(inode, &clu);
> +		if (ret)
> +			goto out;
> +		start_clu = clu.dir;
> +		clu_size = sbi->cluster_size;
> +	}
> +
> +	/* update the directory entry */
> +	/* fill the dos name directory entry information of the created
> file.
> +	 * the first cluster is not determined yet. (0)
> +	 */
> +	ret = exfat_init_dir_entry(inode, p_dir, dentry, type,
> +		start_clu, clu_size);
> +	if (ret)
> +		goto out;
> +
> +	ret = exfat_init_ext_entry(inode, p_dir, dentry, num_entries,
> &uniname);
> +	if (ret)
> +		goto out;
> +
> +	memcpy(&info->dir, p_dir, sizeof(struct exfat_chain));
> +	info->entry = dentry;
> +	info->flags = ALLOC_NO_FAT_CHAIN;
> +	info->type = type;
> +
> +	if (type == TYPE_FILE) {
> +		info->attr = ATTR_ARCHIVE;
> +		info->start_clu = EOF_CLUSTER;
> +		info->size = 0;
> +		info->num_subdirs = 0;
> +	} else {
> +		int count;
> +		struct exfat_chain cdir;
> +
> +		info->attr = ATTR_SUBDIR;
> +		info->start_clu = start_clu;
> +		info->size = clu_size;
> +
> +		exfat_chain_set(&cdir, info->start_clu,
> +			EXFAT_B_TO_CLU(info->size, sbi), info->flags);
> +		count = exfat_count_dir_entries(sb, &cdir);
> +		if (count < 0)
> +			return -EIO;
> +		info->num_subdirs = count + EXFAT_MIN_SUBDIR;
> +	}
> +	memset(&info->create_timestamp, 0,
> +			sizeof(struct exfat_date_time));
> +	memset(&info->modify_timestamp, 0,
> +			sizeof(struct exfat_date_time));
> +	memset(&info->access_timestamp, 0,
> +			sizeof(struct exfat_date_time));
> +out:
> +	return ret;
> +}
> +
> +static int exfat_create(struct inode *dir, struct dentry *dentry,
> umode_t mode,
> +		bool excl)
> +{
> +	struct super_block *sb = dir->i_sb;
> +	struct inode *inode;
> +	struct exfat_chain cdir;
> +	struct exfat_dir_entry info;
> +	loff_t i_pos;
> +	int err;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +	err = exfat_add_entry(dir, dentry->d_name.name, &cdir,
> TYPE_FILE,
> +		&info);
> +	exfat_set_vol_flags(sb, VOL_CLEAN);
> +	if (err)
> +		goto unlock;
> +
> +	inode_inc_iversion(dir);
> +	dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
> +	if (IS_DIRSYNC(dir))
> +		exfat_sync_inode(dir);
> +	else
> +		mark_inode_dirty(dir);
> +
> +	i_pos = exfat_make_i_pos(&info);
> +	inode = exfat_build_inode(sb, &info, i_pos);
> +	if (IS_ERR(inode))
> +		goto unlock;
> +
> +	inode_inc_iversion(inode);
> +	inode->i_mtime = inode->i_atime = inode->i_ctime =
> current_time(inode);
> +	/* timestamp is already written, so mark_inode_dirty() is
> unneeded. */
> +
> +	d_instantiate(dentry, inode);
> +unlock:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return err;
> +}
> +
> +/* lookup a file */
> +static int exfat_find(struct inode *dir, struct qstr *qname,
> +		struct exfat_dir_entry *info)
> +{
> +	int ret, dentry, num_entries, count;
> +	struct exfat_chain cdir;
> +	struct exfat_uni_name uni_name;
> +	struct exfat_dentry *ep, *ep2;
> +	struct exfat_entry_set_cache *es = NULL;
> +	struct super_block *sb = dir->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(dir);
> +	struct exfat_timestamp tm;
> +
> +	if (qname->len == 0)
> +		return -ENOENT;
> +
> +	/* check the validity of directory name in the given pathname
> */
> +	ret = exfat_resolve_path_for_lookup(dir, qname->name, &cdir,
> &uni_name);
> +	if (ret)
> +		return ret;
> +
> +	num_entries = exfat_get_num_entries(&uni_name);
> +	if (num_entries < 0)
> +		return num_entries;
> +
> +	/* check the validation of hint_stat and initialize it if
> required */
> +	if (ei->version != (inode_peek_iversion_raw(dir) & 0xffffffff))
> {
> +		ei->hint_stat.clu = cdir.dir;
> +		ei->hint_stat.eidx = 0;
> +		ei->version = (inode_peek_iversion_raw(dir) &
> 0xffffffff);
> +		ei->hint_femp.eidx = EXFAT_HINT_NONE;
> +	}
> +
> +	/* search the file name for directories */
> +	dentry = exfat_find_dir_entry(sb, ei, &cdir, &uni_name,
> +			num_entries, TYPE_ALL);
> +
> +	if ((dentry < 0) && (dentry != -EEXIST))
> +		return dentry; /* -error value */
> +
> +	memcpy(&info->dir, &cdir.dir, sizeof(struct exfat_chain));
> +	info->entry = dentry;
> +	info->num_subdirs = 0;
> +
> +	/* root directory itself */
> +	if (unlikely(dentry == -EEXIST)) {
> +		int num_clu = 0;
> +
> +		info->type = TYPE_DIR;
> +		info->attr = ATTR_SUBDIR;
> +		info->flags = ALLOC_FAT_CHAIN;
> +		info->start_clu = sbi->root_dir;
> +		memset(&info->create_timestamp, 0,
> +				sizeof(struct exfat_date_time));
> +		memset(&info->modify_timestamp, 0,
> +				sizeof(struct exfat_date_time));
> +		memset(&info->access_timestamp, 0,
> +				sizeof(struct exfat_date_time));
> +
> +		exfat_chain_set(&cdir, sbi->root_dir, 0,
> ALLOC_FAT_CHAIN);
> +		if (exfat_count_num_clusters(sb, &cdir, &num_clu))
> +			return -EIO;
> +		info->size = num_clu << sbi->cluster_size_bits;
> +
> +		count = exfat_count_dir_entries(sb, &cdir);
> +		if (count < 0)
> +			return -EIO;
> +
> +		info->num_subdirs = count;
> +	} else {
> +		es = exfat_get_dentry_set(sb, &cdir, dentry,
> ES_2_ENTRIES, &ep);
> +		if (!es)
> +			return -EIO;
> +		ep2 = ep + 1;


Ditto. The ep2 could point out on the garbage!!!

Thanks,
Viacheslav Dubeyko.


> +
> +		info->type = exfat_get_entry_type(ep);
> +		info->attr = le16_to_cpu(ep->file_attr);
> +		info->size = le64_to_cpu(ep2->stream_valid_size);
> +		if ((info->type == TYPE_FILE) && (info->size == 0)) {
> +			info->flags = ALLOC_NO_FAT_CHAIN;
> +			info->start_clu = EOF_CLUSTER;
> +		} else {
> +			info->flags = ep2->stream_flags;
> +			info->start_clu = le32_to_cpu(ep2-
> >stream_start_clu);
> +		}
> +
> +		if (ei->start_clu == FREE_CLUSTER) {
> +			exfat_fs_error(sb,
> +				"non-zero size file starts with zero
> cluster (size : %llu, p_dir : %u, entry : 0x%08x)",
> +				i_size_read(dir), ei->dir.dir, ei-
> >entry);
> +			return -EIO;
> +		}
> +
> +		exfat_get_entry_time(ep, &tm, TM_CREATE);
> +		info->create_timestamp.year = tm.year;
> +		info->create_timestamp.month = tm.mon;
> +		info->create_timestamp.day = tm.day;
> +		info->create_timestamp.hour = tm.hour;
> +		info->create_timestamp.minute = tm.min;
> +		info->create_timestamp.second = tm.sec;
> +		info->create_timestamp.milli_second = 0;
> +
> +		exfat_get_entry_time(ep, &tm, TM_MODIFY);
> +		info->modify_timestamp.year = tm.year;
> +		info->modify_timestamp.month = tm.mon;
> +		info->modify_timestamp.day = tm.day;
> +		info->modify_timestamp.hour = tm.hour;
> +		info->modify_timestamp.minute = tm.min;
> +		info->modify_timestamp.second = tm.sec;
> +		info->modify_timestamp.milli_second = 0;
> +
> +		memset(&info->access_timestamp, 0,
> +				sizeof(struct exfat_date_time));
> +		kfree(es);
> +
> +		if (info->type == TYPE_DIR) {
> +			exfat_chain_set(&cdir, info->start_clu,
> +				EXFAT_B_TO_CLU(info->size, sbi), info-
> >flags);
> +			count = exfat_count_dir_entries(sb, &cdir);
> +			if (count < 0)
> +				return -EIO;
> +
> +			info->num_subdirs = count + EXFAT_MIN_SUBDIR;
> +		}
> +	}
> +	return 0;
> +}
> +
> +static int exfat_d_anon_disconn(struct dentry *dentry)
> +{
> +	return IS_ROOT(dentry) && (dentry->d_flags &
> DCACHE_DISCONNECTED);
> +}
> +
> +static struct dentry *exfat_lookup(struct inode *dir, struct dentry
> *dentry,
> +		unsigned int flags)
> +{
> +	struct super_block *sb = dir->i_sb;
> +	struct inode *inode;
> +	struct dentry *alias;
> +	struct exfat_dir_entry info;
> +	int err;
> +	loff_t i_pos;
> +	mode_t i_mode;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	err = exfat_find(dir, &dentry->d_name, &info);
> +	if (err) {
> +		if (err == -ENOENT) {
> +			inode = NULL;
> +			goto out;
> +		}
> +		goto unlock;
> +	}
> +
> +	i_pos = exfat_make_i_pos(&info);
> +	inode = exfat_build_inode(sb, &info, i_pos);
> +	if (IS_ERR(inode)) {
> +		err = PTR_ERR(inode);
> +		goto unlock;
> +	}
> +
> +	i_mode = inode->i_mode;
> +	alias = d_find_alias(inode);
> +
> +	/*
> +	 * Checking "alias->d_parent == dentry->d_parent" to make sure
> +	 * FS is not corrupted (especially double linked dir).
> +	 */
> +	if (alias && alias->d_parent == dentry->d_parent &&
> +			!exfat_d_anon_disconn(alias)) {
> +
> +		/*
> +		 * Unhashed alias is able to exist because of
> revalidate()
> +		 * called by lookup_fast. You can easily make this
> status
> +		 * by calling create and lookup concurrently
> +		 * In such case, we reuse an alias instead of new
> dentry
> +		 */
> +		if (d_unhashed(alias)) {
> +			WARN_ON(alias->d_name.hash_len !=
> +				dentry->d_name.hash_len);
> +			exfat_msg(sb, KERN_INFO,
> +				"rehashed a dentry(%p) in read lookup",
> alias);
> +			d_drop(dentry);
> +			d_rehash(alias);
> +		} else if (!S_ISDIR(i_mode)) {
> +			/*
> +			 * This inode has non anonymous-
> DCACHE_DISCONNECTED
> +			 * dentry. This means, the user did ->lookup()
> by an
> +			 * another name (longname vs 8.3 alias of it)
> in past.
> +			 *
> +			 * Switch to new one for reason of locality if
> possible.
> +			 */
> +			d_move(alias, dentry);
> +		}
> +		iput(inode);
> +		mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +		return alias;
> +	}
> +	dput(alias);
> +out:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	if (!inode)
> +		exfat_d_version_set(dentry, inode_query_iversion(dir));
> +
> +	return d_splice_alias(inode, dentry);
> +unlock:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return ERR_PTR(err);
> +}
> +
> +/* remove an entry, BUT don't truncate */
> +static int exfat_unlink(struct inode *dir, struct dentry *dentry)
> +{
> +	struct exfat_chain cdir;
> +	struct exfat_dentry *ep;
> +	struct super_block *sb = dir->i_sb;
> +	struct inode *inode = dentry->d_inode;
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	struct buffer_head *bh;
> +	sector_t sector;
> +	int num_entries, entry, err = 0;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	exfat_chain_dup(&cdir, &ei->dir);
> +	entry = ei->entry;
> +	if (ei->dir.dir == DIR_DELETED) {
> +		exfat_msg(sb, KERN_ERR, "abnormal access to deleted
> dentry");
> +		err = -ENOENT;
> +		goto unlock;
> +	}
> +
> +	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
> +	if (!ep) {
> +		err = -EIO;
> +		goto unlock;
> +	}
> +	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
> +	if (num_entries < 0) {
> +		err = -EIO;
> +		brelse(bh);
> +		goto unlock;
> +	}
> +	num_entries++;
> +	brelse(bh);
> +
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +	/* update the directory entry */
> +	if (exfat_remove_entries(dir, &cdir, entry, 0, num_entries)) {
> +		err = -EIO;
> +		goto unlock;
> +	}
> +
> +	/* This doesn't modify ei */
> +	ei->dir.dir = DIR_DELETED;
> +	exfat_set_vol_flags(sb, VOL_CLEAN);
> +
> +	inode_inc_iversion(dir);
> +	dir->i_mtime = dir->i_atime = current_time(dir);
> +	if (IS_DIRSYNC(dir))
> +		exfat_sync_inode(dir);
> +	else
> +		mark_inode_dirty(dir);
> +
> +	clear_nlink(inode);
> +	inode->i_mtime = inode->i_atime = current_time(inode);
> +	exfat_unhash_inode(inode);
> +	exfat_d_version_set(dentry, inode_query_iversion(dir));
> +unlock:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return err;
> +}
> +
> +static int exfat_mkdir(struct inode *dir, struct dentry *dentry,
> umode_t mode)
> +{
> +	struct super_block *sb = dir->i_sb;
> +	struct inode *inode;
> +	struct exfat_dir_entry info;
> +	struct exfat_chain cdir;
> +	loff_t i_pos;
> +	int err;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +	err = exfat_add_entry(dir, dentry->d_name.name, &cdir,
> TYPE_DIR,
> +		&info);
> +	exfat_set_vol_flags(sb, VOL_CLEAN);
> +	if (err)
> +		goto unlock;
> +
> +	inode_inc_iversion(dir);
> +	dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
> +	if (IS_DIRSYNC(dir))
> +		exfat_sync_inode(dir);
> +	else
> +		mark_inode_dirty(dir);
> +	inc_nlink(dir);
> +
> +	i_pos = exfat_make_i_pos(&info);
> +	inode = exfat_build_inode(sb, &info, i_pos);
> +	if (IS_ERR(inode)) {
> +		err = PTR_ERR(inode);
> +		goto unlock;
> +	}
> +
> +	inode_inc_iversion(inode);
> +	inode->i_mtime = inode->i_atime = inode->i_ctime =
> current_time(inode);
> +	/* timestamp is already written, so mark_inode_dirty() is
> unneeded. */
> +
> +	d_instantiate(dentry, inode);
> +
> +unlock:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return err;
> +}
> +
> +static int exfat_check_dir_empty(struct super_block *sb,
> +		struct exfat_chain *p_dir)
> +{
> +	int i, dentries_per_clu;
> +	unsigned int type;
> +	struct exfat_chain clu;
> +	struct exfat_dentry *ep;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct buffer_head *bh;
> +
> +	dentries_per_clu = sbi->dentries_per_clu;
> +
> +	exfat_chain_dup(&clu, p_dir);
> +
> +	while (clu.dir != EOF_CLUSTER) {
> +		for (i = 0; i < dentries_per_clu; i++) {
> +			ep = exfat_get_dentry(sb, &clu, i, &bh, NULL);
> +			if (!ep)
> +				return -EIO;
> +			type = exfat_get_entry_type(ep);
> +			brelse(bh);
> +			if (type == TYPE_UNUSED)
> +				return 0;
> +
> +			if (type != TYPE_FILE && type != TYPE_DIR)
> +				continue;
> +
> +			return -ENOTEMPTY;
> +		}
> +
> +		if (clu.flags == ALLOC_NO_FAT_CHAIN) {
> +			if (--clu.size > 0)
> +				clu.dir++;
> +			else
> +				clu.dir = EOF_CLUSTER;
> +		} else {
> +			if (exfat_get_next_cluster(sb, &(clu.dir)))
> +				return -EIO;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int exfat_rmdir(struct inode *dir, struct dentry *dentry)
> +{
> +	struct inode *inode = dentry->d_inode;
> +	struct exfat_dentry *ep;
> +	struct exfat_chain cdir, clu_to_free;
> +	struct super_block *sb = inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	struct exfat_inode_info *ei = EXFAT_I(inode);
> +	struct buffer_head *bh;
> +	sector_t sector;
> +	int num_entries, entry, err;
> +
> +	mutex_lock(&EXFAT_SB(inode->i_sb)->s_lock);
> +
> +	exfat_chain_dup(&cdir, &ei->dir);
> +	entry = ei->entry;
> +
> +	if (ei->dir.dir == DIR_DELETED) {
> +		exfat_msg(sb, KERN_ERR, "abnormal access to deleted
> dentry");
> +		err = -ENOENT;
> +		goto unlock;
> +	}
> +
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +	exfat_chain_set(&clu_to_free, ei->start_clu,
> +		EXFAT_B_TO_CLU_ROUND_UP(i_size_read(inode), sbi), ei-
> >flags);
> +
> +	err = exfat_check_dir_empty(sb, &clu_to_free);
> +	if (err) {
> +		if (err == -EIO)
> +			exfat_msg(sb, KERN_ERR,
> +				"failed to exfat_check_dir_empty :
> err(%d)",
> +				err);
> +		goto unlock;
> +	}
> +
> +	ep = exfat_get_dentry(sb, &cdir, entry, &bh, &sector);
> +	if (!ep) {
> +		err = -EIO;
> +		goto unlock;
> +	}
> +
> +	num_entries = exfat_count_ext_entries(sb, &cdir, entry, ep);
> +	if (num_entries < 0) {
> +		err = -EIO;
> +		brelse(bh);
> +		goto unlock;
> +	}
> +	num_entries++;
> +	brelse(bh);
> +
> +	err = exfat_remove_entries(dir, &cdir, entry, 0, num_entries);
> +	if (err) {
> +		exfat_msg(sb, KERN_ERR,
> +				"failed to exfat_remove_entries :
> err(%d)",
> +				err);
> +		goto unlock;
> +	}
> +	ei->dir.dir = DIR_DELETED;
> +	exfat_set_vol_flags(sb, VOL_CLEAN);
> +
> +	inode_inc_iversion(dir);
> +	dir->i_mtime = dir->i_atime = current_time(dir);
> +	if (IS_DIRSYNC(dir))
> +		exfat_sync_inode(dir);
> +	else
> +		mark_inode_dirty(dir);
> +	drop_nlink(dir);
> +
> +	clear_nlink(inode);
> +	inode->i_mtime = inode->i_atime = current_time(inode);
> +	exfat_unhash_inode(inode);
> +	exfat_d_version_set(dentry, inode_query_iversion(dir));
> +unlock:
> +	mutex_unlock(&EXFAT_SB(inode->i_sb)->s_lock);
> +	return err;
> +}
> +
> +static int exfat_rename_file(struct inode *inode, struct exfat_chain
> *p_dir,
> +		int oldentry, struct exfat_uni_name *p_uniname,
> +		struct exfat_inode_info *ei)
> +{
> +	int ret, num_old_entries, num_new_entries;
> +	sector_t sector_old, sector_new;
> +	struct exfat_dentry *epold, *epnew;
> +	struct super_block *sb = inode->i_sb;
> +	struct buffer_head *new_bh, *old_bh;
> +	int sync = IS_DIRSYNC(inode);
> +
> +	epold = exfat_get_dentry(sb, p_dir, oldentry, &old_bh,
> &sector_old);
> +	if (!epold)
> +		return -EIO;
> +
> +	num_old_entries = exfat_count_ext_entries(sb, p_dir, oldentry,
> epold);
> +	if (num_old_entries < 0)
> +		return -EIO;
> +	num_old_entries++;
> +
> +	num_new_entries = exfat_get_num_entries(p_uniname);
> +	if (num_new_entries < 0)
> +		return num_new_entries;
> +
> +	if (num_old_entries < num_new_entries) {
> +		int newentry;
> +
> +		newentry =
> +			exfat_find_empty_entry(inode, p_dir,
> num_new_entries);
> +		if (newentry < 0)
> +			return newentry; /* -EIO or -ENOSPC */
> +
> +		epnew = exfat_get_dentry(sb, p_dir, newentry, &new_bh,
> +			&sector_new);
> +		if (!epnew)
> +			return -EIO;
> +
> +		memcpy(epnew, epold, DENTRY_SIZE);
> +		if (exfat_get_entry_type(epnew) == TYPE_FILE) {
> +			epnew->file_attr |= ATTR_ARCHIVE_LE;
> +			ei->attr |= ATTR_ARCHIVE;
> +		}
> +		exfat_update_bh(sb, new_bh, sync);
> +		brelse(old_bh);
> +		brelse(new_bh);
> +
> +		epold = exfat_get_dentry(sb, p_dir, oldentry + 1,
> &old_bh,
> +			&sector_old);
> +		epnew = exfat_get_dentry(sb, p_dir, newentry + 1,
> &new_bh,
> +			&sector_new);
> +		if (!epold || !epnew)
> +			return -EIO;
> +
> +		memcpy(epnew, epold, DENTRY_SIZE);
> +		exfat_update_bh(sb, new_bh, sync);
> +		brelse(old_bh);
> +		brelse(new_bh);
> +
> +		ret = exfat_init_ext_entry(inode, p_dir, newentry,
> +			num_new_entries, p_uniname);
> +		if (ret)
> +			return ret;
> +
> +		exfat_remove_entries(inode, p_dir, oldentry, 0,
> +			num_old_entries);
> +		ei->entry = newentry;
> +	} else {
> +		if (exfat_get_entry_type(epold) == TYPE_FILE) {
> +			epold->file_attr |= ATTR_ARCHIVE_LE;
> +			ei->attr |= ATTR_ARCHIVE;
> +		}
> +		exfat_update_bh(sb, old_bh, sync);
> +		brelse(old_bh);
> +		ret = exfat_init_ext_entry(inode, p_dir, oldentry,
> +			num_new_entries, p_uniname);
> +		if (ret)
> +			return ret;
> +
> +		exfat_remove_entries(inode, p_dir, oldentry,
> num_new_entries,
> +			num_old_entries);
> +	}
> +	return 0;
> +}
> +
> +static int exfat_move_file(struct inode *inode, struct exfat_chain
> *p_olddir,
> +		int oldentry, struct exfat_chain *p_newdir,
> +		struct exfat_uni_name *p_uniname, struct
> exfat_inode_info *ei)
> +{
> +	int ret, newentry, num_new_entries, num_old_entries;
> +	sector_t sector_mov, sector_new;
> +	struct exfat_dentry *epmov, *epnew;
> +	struct super_block *sb = inode->i_sb;
> +	struct buffer_head *mov_bh, *new_bh;
> +
> +	epmov = exfat_get_dentry(sb, p_olddir, oldentry, &mov_bh,
> &sector_mov);
> +	if (!epmov)
> +		return -EIO;
> +
> +	/* check if the source and target directory is the same */
> +	if (exfat_get_entry_type(epmov) == TYPE_DIR &&
> +	    le32_to_cpu(epmov->stream_start_clu) == p_newdir->dir)
> +		return -EINVAL;
> +
> +	num_old_entries = exfat_count_ext_entries(sb, p_olddir,
> oldentry,
> +		epmov);
> +	if (num_old_entries < 0)
> +		return -EIO;
> +	num_old_entries++;
> +
> +	num_new_entries = exfat_get_num_entries(p_uniname);
> +	if (num_new_entries < 0)
> +		return num_new_entries;
> +
> +	newentry = exfat_find_empty_entry(inode, p_newdir,
> num_new_entries);
> +	if (newentry < 0)
> +		return newentry; /* -EIO or -ENOSPC */
> +
> +	epnew = exfat_get_dentry(sb, p_newdir, newentry, &new_bh,
> &sector_new);
> +	if (!epnew)
> +		return -EIO;
> +
> +	memcpy(epnew, epmov, DENTRY_SIZE);
> +	if (exfat_get_entry_type(epnew) == TYPE_FILE) {
> +		epnew->file_attr |= ATTR_ARCHIVE_LE;
> +		ei->attr |= ATTR_ARCHIVE;
> +	}
> +	exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
> +	brelse(mov_bh);
> +	brelse(new_bh);
> +
> +	epmov = exfat_get_dentry(sb, p_olddir, oldentry + 1, &mov_bh,
> +		&sector_mov);
> +	epnew = exfat_get_dentry(sb, p_newdir, newentry + 1, &new_bh,
> +		&sector_new);
> +	if (!epmov || !epnew)
> +		return -EIO;
> +
> +	memcpy(epnew, epmov, DENTRY_SIZE);
> +	exfat_update_bh(sb, new_bh, IS_DIRSYNC(inode));
> +	brelse(mov_bh);
> +	brelse(new_bh);
> +
> +	ret = exfat_init_ext_entry(inode, p_newdir, newentry,
> num_new_entries,
> +		p_uniname);
> +	if (ret)
> +		return ret;
> +
> +	exfat_remove_entries(inode, p_olddir, oldentry, 0,
> num_old_entries);
> +
> +	exfat_chain_set(&ei->dir, p_newdir->dir, p_newdir->size,
> +		p_newdir->flags);
> +
> +	ei->entry = newentry;
> +	return 0;
> +}
> +
> +static void exfat_update_parent_info(struct exfat_inode_info *ei,
> +		struct inode *parent_inode)
> +{
> +	struct exfat_sb_info *sbi = EXFAT_SB(parent_inode->i_sb);
> +	struct exfat_inode_info *parent_ei = EXFAT_I(parent_inode);
> +	loff_t parent_isize = i_size_read(parent_inode);
> +
> +	/*
> +	 * the problem that struct exfat_inode_info caches wrong parent
> info.
> +	 *
> +	 * because of flag-mismatch of ei->dir,
> +	 * there is abnormal traversing cluster chain.
> +	 */
> +	if (unlikely(parent_ei->flags != ei->dir.flags ||
> +		     parent_isize != EXFAT_CLU_TO_B(ei->dir.size, sbi)
> ||
> +		     parent_ei->start_clu != ei->dir.dir)) {
> +		exfat_chain_set(&ei->dir, parent_ei->start_clu,
> +			EXFAT_B_TO_CLU_ROUND_UP(parent_isize, sbi),
> +			parent_ei->flags);
> +	}
> +}
> +
> +/* rename or move a old file into a new file */
> +static int __exfat_rename(struct inode *old_parent_inode,
> +		struct exfat_inode_info *ei, struct inode
> *new_parent_inode,
> +		struct dentry *new_dentry)
> +{
> +	int ret;
> +	int dentry;
> +	struct exfat_chain olddir, newdir;
> +	struct exfat_chain *p_dir = NULL;
> +	struct exfat_uni_name uni_name;
> +	struct exfat_dentry *ep;
> +	struct super_block *sb = old_parent_inode->i_sb;
> +	struct exfat_sb_info *sbi = EXFAT_SB(sb);
> +	const unsigned char *new_path = new_dentry->d_name.name;
> +	struct inode *new_inode = new_dentry->d_inode;
> +	int num_entries;
> +	struct exfat_inode_info *new_ei = NULL;
> +	unsigned int new_entry_type = TYPE_UNUSED;
> +	int new_entry = 0;
> +	struct buffer_head *old_bh, *new_bh = NULL;
> +
> +	/* check the validity of pointer parameters */
> +	if (new_path == NULL || strlen(new_path) == 0)
> +		return -EINVAL;
> +
> +	if (ei->dir.dir == DIR_DELETED) {
> +		exfat_msg(sb, KERN_ERR,
> +				"abnormal access to deleted source
> dentry");
> +		return -ENOENT;
> +	}
> +
> +	exfat_update_parent_info(ei, old_parent_inode);
> +
> +	exfat_chain_dup(&olddir, &ei->dir);
> +	dentry = ei->entry;
> +
> +	ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh, NULL);
> +	if (!ep) {
> +		ret = -EIO;
> +		goto out;
> +	}
> +	brelse(old_bh);
> +
> +	/* check whether new dir is existing directory and empty */
> +	if (new_inode) {
> +		ret = -EIO;
> +		new_ei = EXFAT_I(new_inode);
> +
> +		if (new_ei->dir.dir == DIR_DELETED) {
> +			exfat_msg(sb, KERN_ERR,
> +				"abnormal access to deleted target
> dentry");
> +			goto out;
> +		}
> +
> +		exfat_update_parent_info(new_ei, new_parent_inode);
> +
> +		p_dir = &(new_ei->dir);
> +		new_entry = new_ei->entry;
> +		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh,
> NULL);
> +		if (!ep)
> +			goto out;
> +
> +		new_entry_type = exfat_get_entry_type(ep);
> +		brelse(new_bh);
> +
> +		/* if new_inode exists, update ei */
> +		if (new_entry_type == TYPE_DIR) {
> +			struct exfat_chain new_clu;
> +
> +			new_clu.dir = new_ei->start_clu;
> +			new_clu.size =
> +				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new
> _inode),
> +				sbi);
> +			new_clu.flags = new_ei->flags;
> +
> +			ret = exfat_check_dir_empty(sb, &new_clu);
> +			if (ret)
> +				goto out;
> +		}
> +	}
> +
> +	/* check the validity of directory name in the given new
> pathname */
> +	ret = exfat_resolve_path(new_parent_inode, new_path, &newdir,
> +			&uni_name);
> +	if (ret)
> +		goto out;
> +
> +	exfat_set_vol_flags(sb, VOL_DIRTY);
> +
> +	if (olddir.dir == newdir.dir)
> +		ret = exfat_rename_file(new_parent_inode, &olddir,
> dentry,
> +				&uni_name, ei);
> +	else
> +		ret = exfat_move_file(new_parent_inode, &olddir,
> dentry,
> +				&newdir, &uni_name, ei);
> +
> +	if (!ret && new_inode) {
> +		/* delete entries of new_dir */
> +		ep = exfat_get_dentry(sb, p_dir, new_entry, &new_bh,
> NULL);
> +		if (!ep) {
> +			ret = -EIO;
> +			goto del_out;
> +		}
> +
> +		num_entries = exfat_count_ext_entries(sb, p_dir,
> new_entry, ep);
> +		if (num_entries < 0) {
> +			ret = -EIO;
> +			goto del_out;
> +		}
> +		brelse(new_bh);
> +
> +		if (exfat_remove_entries(new_inode, p_dir, new_entry,
> 0,
> +				num_entries + 1)) {
> +			ret = -EIO;
> +			goto del_out;
> +		}
> +
> +		/* Free the clusters if new_inode is a dir(as if
> exfat_rmdir) */
> +		if (new_entry_type == TYPE_DIR) {
> +			/* new_ei, new_clu_to_free */
> +			struct exfat_chain new_clu_to_free;
> +
> +			exfat_chain_set(&new_clu_to_free, new_ei-
> >start_clu,
> +				EXFAT_B_TO_CLU_ROUND_UP(i_size_read(new
> _inode),
> +				sbi), new_ei->flags);
> +
> +			if (exfat_free_cluster(new_inode,
> &new_clu_to_free)) {
> +				/* just set I/O error only */
> +				ret = -EIO;
> +			}
> +
> +			i_size_write(new_inode, 0);
> +			new_ei->start_clu = EOF_CLUSTER;
> +			new_ei->flags = ALLOC_NO_FAT_CHAIN;
> +		}
> +del_out:
> +		/* Update new_inode ei
> +		 * Prevent syncing removed new_inode
> +		 * (new_ei is already initialized above code ("if
> (new_inode)")
> +		 */
> +		new_ei->dir.dir = DIR_DELETED;
> +	}
> +	exfat_set_vol_flags(sb, VOL_CLEAN);
> +out:
> +	return ret;
> +}
> +
> +static int exfat_rename(struct inode *old_dir, struct dentry
> *old_dentry,
> +		struct inode *new_dir, struct dentry *new_dentry,
> +		unsigned int flags)
> +{
> +	struct inode *old_inode, *new_inode;
> +	struct super_block *sb = old_dir->i_sb;
> +	loff_t i_pos;
> +	int err;
> +
> +	/*
> +	 * The VFS already checks for existence, so for local
> filesystems
> +	 * the RENAME_NOREPLACE implementation is equivalent to plain
> rename.
> +	 * Don't support any other flags
> +	 */
> +	if (flags & ~RENAME_NOREPLACE)
> +		return -EINVAL;
> +
> +	mutex_lock(&EXFAT_SB(sb)->s_lock);
> +	old_inode = old_dentry->d_inode;
> +	new_inode = new_dentry->d_inode;
> +
> +	err = __exfat_rename(old_dir, EXFAT_I(old_inode), new_dir,
> new_dentry);
> +	if (err)
> +		goto unlock;
> +
> +	inode_inc_iversion(new_dir);
> +	new_dir->i_ctime = new_dir->i_mtime = new_dir->i_atime =
> +		current_time(new_dir);
> +	if (IS_DIRSYNC(new_dir))
> +		exfat_sync_inode(new_dir);
> +	else
> +		mark_inode_dirty(new_dir);
> +
> +	i_pos = ((loff_t)EXFAT_I(old_inode)->dir.dir << 32) |
> +		(EXFAT_I(old_inode)->entry & 0xffffffff);
> +	exfat_unhash_inode(old_inode);
> +	exfat_hash_inode(old_inode, i_pos);
> +	if (IS_DIRSYNC(new_dir))
> +		exfat_sync_inode(old_inode);
> +	else
> +		mark_inode_dirty(old_inode);
> +
> +	if (S_ISDIR(old_inode->i_mode) && old_dir != new_dir) {
> +		drop_nlink(old_dir);
> +		if (!new_inode)
> +			inc_nlink(new_dir);
> +	}
> +
> +	inode_inc_iversion(old_dir);
> +	old_dir->i_ctime = old_dir->i_mtime = current_time(old_dir);
> +	if (IS_DIRSYNC(old_dir))
> +		exfat_sync_inode(old_dir);
> +	else
> +		mark_inode_dirty(old_dir);
> +
> +	if (new_inode) {
> +		exfat_unhash_inode(new_inode);
> +
> +		/* skip drop_nlink if new_inode already has been
> dropped */
> +		if (new_inode->i_nlink) {
> +			drop_nlink(new_inode);
> +			if (S_ISDIR(new_inode->i_mode))
> +				drop_nlink(new_inode);
> +		} else {
> +			exfat_msg(sb, KERN_WARNING,
> +					"abnormal access to an inode
> dropped");
> +			WARN_ON(new_inode->i_nlink == 0);
> +		}
> +		new_inode->i_ctime = current_time(new_inode);
> +	}
> +
> +unlock:
> +	mutex_unlock(&EXFAT_SB(sb)->s_lock);
> +	return err;
> +}
> +
> +const struct inode_operations exfat_dir_inode_operations = {
> +	.create		= exfat_create,
> +	.lookup		= exfat_lookup,
> +	.unlink		= exfat_unlink,
> +	.mkdir		= exfat_mkdir,
> +	.rmdir		= exfat_rmdir,
> +	.rename		= exfat_rename,
> +	.setattr	= exfat_setattr,
> +	.getattr	= exfat_getattr,
> +};