From 5f2aa075070cf5b2e6aae011d5a3390408d7d913 Mon Sep 17 00:00:00 2001

From: Namjae Jeon <namjae.jeon@samsung.com>

Date: Mon, 2 Mar 2020 15:21:34 +0900

Subject: [Backport 5f2aa075070c] exfat: add inode operations

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

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>

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>

Reviewed-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

---

 src/inode.c |  671 +++++++++++++++++++++

 src/namei.c | 1448 ++++++++++++++++++++++++++++++++++++++++++++++

 2 files changed, 2119 insertions(+)

 create mode 100644 src/inode.c

 create mode 100644 src/namei.c

diff --git a/src/inode.c b/src/inode.c

new file mode 100644

index 0000000000000000000000000000000000000000..06887492f54b791506d2f7c76eb3ef073b72026d

--- /dev/null

+++ b/src/inode.c

@@ -0,0 +1,671 @@

+// 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"

+

+static int __exfat_write_inode(struct inode *inode, int sync)

+{

+	int ret = -EIO;

+	unsigned long long on_disk_size;

+	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);

+	bool is_dir = (ei->type == TYPE_DIR) ? true : false;

+

+	if (inode->i_ino == EXFAT_ROOT_INO)

+		return 0;

+

+	/*

+	 * 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;

+

+	ep->dentry.file.attr = cpu_to_le16(exfat_make_attr(inode));

+

+	/* set FILE_INFO structure using the acquired struct exfat_dentry */

+	exfat_set_entry_time(sbi, &ei->i_crtime,

+			&ep->dentry.file.create_tz,

+			&ep->dentry.file.create_time,

+			&ep->dentry.file.create_date,

+			&ep->dentry.file.create_time_ms);

+	exfat_set_entry_time(sbi, &inode->i_mtime,

+			&ep->dentry.file.modify_tz,

+			&ep->dentry.file.modify_time,

+			&ep->dentry.file.modify_date,

+			&ep->dentry.file.modify_time_ms);

+	exfat_set_entry_time(sbi, &inode->i_atime,

+			&ep->dentry.file.access_tz,

+			&ep->dentry.file.access_time,

+			&ep->dentry.file.access_date,

+			NULL);

+

+	/* File size should be zero if there is no cluster allocated */

+	on_disk_size = i_size_read(inode);

+

+	if (ei->start_clu == EXFAT_EOF_CLUSTER)

+		on_disk_size = 0;

+

+	ep2->dentry.stream.valid_size = cpu_to_le64(on_disk_size);

+	ep2->dentry.stream.size = ep2->dentry.stream.valid_size;

+

+	ret = exfat_update_dir_chksum_with_entry_set(sb, es, sync);

+	kfree(es);

+	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 = EXFAT_EOF_CLUSTER;

+		return 0;

+	}

+

+	*clu = last_clu = ei->start_clu;

+

+	if (ei->flags == ALLOC_NO_FAT_CHAIN) {

+		if (clu_offset > 0 && *clu != EXFAT_EOF_CLUSTER) {

+			last_clu += clu_offset - 1;

+

+			if (clu_offset == num_clusters)

+				*clu = EXFAT_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 != EXFAT_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 != EXFAT_EOF_CLUSTER) {

+			last_clu = *clu;

+			if (exfat_get_next_cluster(sb, clu))

+				return -EIO;

+			clu_offset--;

+		}

+	}

+

+	if (*clu == EXFAT_EOF_CLUSTER) {

+		exfat_set_vol_flags(sb, VOL_DIRTY);

+

+		new_clu.dir = (last_clu == EXFAT_EOF_CLUSTER) ?

+				EXFAT_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 == EXFAT_EOF_CLUSTER ||

+		    new_clu.dir == EXFAT_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 == EXFAT_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->dentry.stream.flags != ei->flags)

+					ep->dentry.stream.flags = ei->flags;

+

+				if (le32_to_cpu(ep->dentry.stream.start_clu) !=

+						ei->start_clu)

+					ep->dentry.stream.start_clu =

+						cpu_to_le32(ei->start_clu);

+

+				ep->dentry.stream.valid_size =

+					cpu_to_le64(i_size_read(inode));

+				ep->dentry.stream.size =

+					ep->dentry.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_map_new_buffer(struct exfat_inode_info *ei,

+		struct buffer_head *bh, loff_t pos)

+{

+	if (buffer_delay(bh) && pos > ei->i_size_aligned)

+		return -EIO;

+	set_buffer_new(bh);

+

+	/*

+	 * Adjust i_size_aligned if i_size_ondisk is bigger than it.

+	 */

+	if (ei->i_size_ondisk > ei->i_size_aligned)

+		ei->i_size_aligned = ei->i_size_ondisk;

+	return 0;

+}

+

+static int exfat_get_block(struct inode *inode, sector_t iblock,

+		struct buffer_head *bh_result, int create)

+{

+	struct exfat_inode_info *ei = EXFAT_I(inode);

+	struct super_block *sb = inode->i_sb;

+	struct exfat_sb_info *sbi = EXFAT_SB(sb);

+	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;

+	int err = 0;

+	unsigned long mapped_blocks = 0;

+	unsigned int cluster, sec_offset;

+	sector_t last_block;

+	sector_t phys = 0;

+	loff_t pos;

+

+	mutex_lock(&sbi->s_lock);

+	last_block = EXFAT_B_TO_BLK_ROUND_UP(i_size_read(inode), sb);

+	if (iblock >= last_block && !create)

+		goto done;

+

+	/* Is this block already allocated? */

+	err = exfat_map_cluster(inode, iblock >> sbi->sect_per_clus_bits,

+			&cluster, 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 (cluster == EXFAT_EOF_CLUSTER)

+		goto done;

+

+	/* sector offset in cluster */

+	sec_offset = iblock & (sbi->sect_per_clus - 1);

+

+	phys = exfat_cluster_to_sector(sbi, cluster) + sec_offset;

+	mapped_blocks = sbi->sect_per_clus - sec_offset;

+	max_blocks = min(mapped_blocks, max_blocks);

+

+	/* Treat newly added block / cluster */

+	if (iblock < last_block)

+		create = 0;

+

+	if (create || buffer_delay(bh_result)) {

+		pos = EXFAT_BLK_TO_B((iblock + 1), sb);

+		if (ei->i_size_ondisk < pos)

+			ei->i_size_ondisk = pos;

+	}

+

+	if (create) {

+		err = exfat_map_new_buffer(ei, bh_result, pos);

+		if (err) {

+			exfat_fs_error(sb,

+					"requested for bmap out of range(pos : (%llu) > i_size_aligned(%llu)\n",

+					pos, ei->i_size_aligned);

+			goto unlock_ret;

+		}

+	}

+

+	if (buffer_delay(bh_result))

+		clear_buffer_delay(bh_result);

+	map_bh(bh_result, sb, phys);

+done:

+	bh_result->b_size = EXFAT_BLK_TO_B(max_blocks, sb);

+unlock_ret:

+	mutex_unlock(&sbi->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;

+}

+

+/*

+ * exfat_block_truncate_page() zeroes out a mapping from file offset `from'

+ * up to the end of the block which corresponds to `from'.

+ * This is required during truncate to physically zeroout the tail end

+ * of that block so it doesn't yield old data if the file is later grown.

+ * Also, avoid causing failure from fsx for cases of "data past EOF"

+ */

+int exfat_block_truncate_page(struct inode *inode, loff_t from)

+{

+	return block_truncate_page(inode->i_mapping, from, exfat_get_block);

+}

+

+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 = EXFAT_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);

+		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);

+		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;

+	inode->i_mtime = info->mtime;

+	inode->i_ctime = info->mtime;

+	ei->i_crtime = info->crtime;

+	inode->i_atime = info->atime;

+

+	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/src/namei.c b/src/namei.c

new file mode 100644

index 0000000000000000000000000000000000000000..a8681d91f56900107ea3df90e2b6dd986045a7bc

--- /dev/null

+++ b/src/namei.c

@@ -0,0 +1,1448 @@

+// 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_d_revalidate(struct dentry *dentry, unsigned int flags)

+{

+	int ret;

+

+	if (flags & LOOKUP_RCU)

+		return -ECHILD;

+

+	/*

+	 * 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;

+

+	spin_lock(&dentry->d_lock);

+	ret = inode_eq_iversion(d_inode(dentry->d_parent),

+			exfat_d_version(dentry));

+	spin_unlock(&dentry->d_lock);

+	return ret;

+}

+

+/* 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;

+}

+

+/*

+ * Compute the hash for the exfat name corresponding to the dentry.  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)

+{

+	struct super_block *sb = dentry->d_sb;

+	struct nls_table *t = EXFAT_SB(sb)->nls_io;

+	const unsigned char *name = qstr->name;

+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);

+	unsigned long hash = init_name_hash(dentry);

+	int i, charlen;

+	wchar_t c;

+

+	for (i = 0; i < len; i += charlen) {

+		charlen = t->char2uni(&name[i], len - i, &c);

+		if (charlen < 0)

+			return charlen;

+		hash = partial_name_hash(exfat_toupper(sb, c), hash);

+	}

+

+	qstr->hash = end_name_hash(hash);

+	return 0;

+}

+

+static int exfat_d_cmp(const struct dentry *dentry, unsigned int len,

+		const char *str, const struct qstr *name)

+{

+	struct super_block *sb = dentry->d_sb;

+	struct nls_table *t = EXFAT_SB(sb)->nls_io;

+	unsigned int alen = exfat_striptail_len(name->len, name->name);

+	unsigned int blen = exfat_striptail_len(len, str);

+	wchar_t c1, c2;

+	int charlen, i;

+

+	if (alen != blen)

+		return 1;

+

+	for (i = 0; i < len; i += charlen) {

+		charlen = t->char2uni(&name->name[i], alen - i, &c1;;

+		if (charlen < 0)

+			return 1;

+		if (charlen != t->char2uni(&str[i], blen - i, &c2))

+			return 1;

+

+		if (exfat_toupper(sb, c1) != exfat_toupper(sb, c2))

+			return 1;

+	}

+

+	return 0;

+}

+

+const struct dentry_operations exfat_dentry_ops = {

+	.d_revalidate	= exfat_d_revalidate,

+	.d_hash		= exfat_d_hash,

+	.d_compare	= exfat_d_cmp,

+};

+

+static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)

+{

+	struct super_block *sb = dentry->d_sb;

+	const unsigned char *name = qstr->name;

+	unsigned int len = exfat_striptail_len(qstr->len, qstr->name);

+	unsigned long hash = init_name_hash(dentry);

+	int i, charlen;

+	unicode_t u;

+

+	for (i = 0; i < len; i += charlen) {

+		charlen = utf8_to_utf32(&name[i], len - i, &u);

+		if (charlen < 0)

+			return charlen;

+

+		/*

+		 * Convert to UTF-16: code points above U+FFFF are encoded as

+		 * surrogate pairs.

+		 * exfat_toupper() works only for code points up to the U+FFFF.

+		 */

+		if (u > 0xFFFF) {

+			hash = partial_name_hash(exfat_high_surrogate(u), hash);

+			hash = partial_name_hash(exfat_low_surrogate(u), hash);

+		} else {

+			hash = partial_name_hash(exfat_toupper(sb, u), hash);

+		}

+	}

+

+	qstr->hash = end_name_hash(hash);

+	return 0;

+}

+

+static int exfat_utf8_d_cmp(const struct dentry *dentry, unsigned int len,

+		const char *str, const struct qstr *name)

+{

+	struct super_block *sb = dentry->d_sb;

+	unsigned int alen = exfat_striptail_len(name->len, name->name);

+	unsigned int blen = exfat_striptail_len(len, str);

+	unicode_t u_a, u_b;

+	int charlen, i;

+

+	if (alen != blen)