fs/ntfs3/namei.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *
  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
  *
  */

 #include <linux/fs.h>
 #include <linux/nls.h>

 #include "debug.h"
 #include "ntfs.h"
 #include "ntfs_fs.h"

 /*
  * fill_name_de - Format NTFS_DE in @buf.
  */
 int fill_name_de(struct ntfs_sb_info *sbi, void *buf, const struct qstr *name,
 		 const struct cpu_str *uni)
 {
 	int err;
 	struct NTFS_DE *e = buf;
 	u16 data_size;
 	struct ATTR_FILE_NAME *fname = (struct ATTR_FILE_NAME *)(e + 1);

 #ifndef CONFIG_NTFS3_64BIT_CLUSTER
 	e->ref.high = fname->home.high = 0;
 #endif
 	if (uni) {
 #ifdef __BIG_ENDIAN
 		int ulen = uni->len;
 		__le16 *uname = fname->name;
 		const u16 *name_cpu = uni->name;

 		while (ulen--)
 			*uname++ = cpu_to_le16(*name_cpu++);
 #else
 		memcpy(fname->name, uni->name, uni->len * sizeof(u16));
 #endif
 		fname->name_len = uni->len;

 	} else {
 		/* Convert input string to unicode. */
 		err = ntfs_nls_to_utf16(sbi, name->name, name->len,
 					(struct cpu_str *)&fname->name_len,
 					NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
 		if (err < 0)
 			return err;
 	}

 	fname->type = FILE_NAME_POSIX;
 	data_size = fname_full_size(fname);

 	e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
 	e->key_size = cpu_to_le16(data_size);
 	e->flags = 0;
 	e->res = 0;

 	return 0;
 }

 /*
  * ntfs_lookup - inode_operations::lookup
  */
 static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry,
 				  u32 flags)
 {
 	struct ntfs_inode *ni = ntfs_i(dir);
 	struct cpu_str *uni = __getname();
 	struct inode *inode;
 	int err;

 	if (!uni)
 		inode = ERR_PTR(-ENOMEM);
 	else {
 		err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
 					dentry->d_name.len, uni, NTFS_NAME_LEN,
 					UTF16_HOST_ENDIAN);
 		if (err < 0)
 			inode = ERR_PTR(err);
 		else {
 			ni_lock(ni);
 			inode = dir_search_u(dir, uni, NULL);
 			ni_unlock(ni);
 		}
 		__putname(uni);
 	}

 	return d_splice_alias(inode, dentry);
 }

 /*
  * ntfs_create - inode_operations::create
  */
 static int ntfs_create(struct user_namespace *mnt_userns, struct inode *dir,
 		       struct dentry *dentry, umode_t mode, bool excl)
 {
 	struct inode *inode;

 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG | mode,
 				  0, NULL, 0, NULL);

 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 }

 /*
  * ntfs_mknod
  *
  * inode_operations::mknod
  */
 static int ntfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
 		      struct dentry *dentry, umode_t mode, dev_t rdev)
 {
 	struct inode *inode;

 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
 				  NULL, 0, NULL);

 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 }

 /*
  * ntfs_link - inode_operations::link
  */
 static int ntfs_link(struct dentry *ode, struct inode *dir, struct dentry *de)
 {
 	int err;
 	struct inode *inode = d_inode(ode);
 	struct ntfs_inode *ni = ntfs_i(inode);

 	if (S_ISDIR(inode->i_mode))
 		return -EPERM;

 	if (inode->i_nlink >= NTFS_LINK_MAX)
 		return -EMLINK;

 	ni_lock_dir(ntfs_i(dir));
 	if (inode != dir)
 		ni_lock(ni);

 	inc_nlink(inode);
 	ihold(inode);

 	err = ntfs_link_inode(inode, de);

 	if (!err) {
 		dir->i_ctime = dir->i_mtime = inode->i_ctime =
 			current_time(dir);
 		mark_inode_dirty(inode);
 		mark_inode_dirty(dir);
 		d_instantiate(de, inode);
 	} else {
 		drop_nlink(inode);
 		iput(inode);
 	}

 	if (inode != dir)
 		ni_unlock(ni);
 	ni_unlock(ntfs_i(dir));

 	return err;
 }

 /*
  * ntfs_unlink - inode_operations::unlink
  */
 static int ntfs_unlink(struct inode *dir, struct dentry *dentry)
 {
 	struct ntfs_inode *ni = ntfs_i(dir);
 	int err;

 	ni_lock_dir(ni);

 	err = ntfs_unlink_inode(dir, dentry);

 	ni_unlock(ni);

 	return err;
 }

 /*
  * ntfs_symlink - inode_operations::symlink
  */
 static int ntfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 			struct dentry *dentry, const char *symname)
 {
 	u32 size = strlen(symname);
 	struct inode *inode;

 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK | 0777,
 				  0, symname, size, NULL);

 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 }

 /*
  * ntfs_mkdir- inode_operations::mkdir
  */
 static int ntfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
 		      struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;

 	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR | mode,
 				  0, NULL, 0, NULL);

 	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
 }

 /*
  * ntfs_rmdir - inode_operations::rm_dir
  */
 static int ntfs_rmdir(struct inode *dir, struct dentry *dentry)
 {
 	struct ntfs_inode *ni = ntfs_i(dir);
 	int err;

 	ni_lock_dir(ni);

 	err = ntfs_unlink_inode(dir, dentry);

 	ni_unlock(ni);

 	return err;
 }

 /*
  * ntfs_rename - inode_operations::rename
  */
 static int ntfs_rename(struct user_namespace *mnt_userns, struct inode *dir,
 		       struct dentry *dentry, struct inode *new_dir,
 		       struct dentry *new_dentry, u32 flags)
 {
 	int err;
 	struct super_block *sb = dir->i_sb;
 	struct ntfs_sb_info *sbi = sb->s_fs_info;
 	struct ntfs_inode *dir_ni = ntfs_i(dir);
 	struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
 	struct inode *inode = d_inode(dentry);
 	struct ntfs_inode *ni = ntfs_i(inode);
 	struct inode *new_inode = d_inode(new_dentry);
 	struct NTFS_DE *de, *new_de;
 	bool is_same, is_bad;
 	/*
 	 * de		- memory of PATH_MAX bytes:
 	 * [0-1024)	- original name (dentry->d_name)
 	 * [1024-2048)	- paired to original name, usually DOS variant of dentry->d_name
 	 * [2048-3072)	- new name (new_dentry->d_name)
 	 */
 	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
 	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
 		      1024);
 	static_assert(PATH_MAX >= 4 * 1024);

 	if (flags & ~RENAME_NOREPLACE)
 		return -EINVAL;

 	is_same = dentry->d_name.len == new_dentry->d_name.len &&
 		  !memcmp(dentry->d_name.name, new_dentry->d_name.name,
 			  dentry->d_name.len);

 	if (is_same && dir == new_dir) {
 		/* Nothing to do. */
 		return 0;
 	}

 	if (ntfs_is_meta_file(sbi, inode->i_ino)) {
 		/* Should we print an error? */
 		return -EINVAL;
 	}

 	if (new_inode) {
 		/* Target name exists. Unlink it. */
 		dget(new_dentry);
 		ni_lock_dir(new_dir_ni);
 		err = ntfs_unlink_inode(new_dir, new_dentry);
 		ni_unlock(new_dir_ni);
 		dput(new_dentry);
 		if (err)
 			return err;
 	}

 	/* Allocate PATH_MAX bytes. */
 	de = __getname();
 	if (!de)
 		return -ENOMEM;

 	/* Translate dentry->d_name into unicode form. */
 	err = fill_name_de(sbi, de, &dentry->d_name, NULL);
 	if (err < 0)
 		goto out;

 	if (is_same) {
 		/* Reuse 'de'. */
 		new_de = de;
 	} else {
 		/* Translate new_dentry->d_name into unicode form. */
 		new_de = Add2Ptr(de, 2048);
 		err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
 		if (err < 0)
 			goto out;
 	}

 	ni_lock_dir(dir_ni);
 	ni_lock(ni);

 	is_bad = false;
 	err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
 	if (is_bad) {
 		/* Restore after failed rename failed too. */
 		make_bad_inode(inode);
 		ntfs_inode_err(inode, "failed to undo rename");
 		ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
 	} else if (!err) {
 		inode->i_ctime = dir->i_ctime = dir->i_mtime =
 			current_time(dir);
 		mark_inode_dirty(inode);
 		mark_inode_dirty(dir);
 		if (dir != new_dir) {
 			new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
 			mark_inode_dirty(new_dir);
 		}

 		if (IS_DIRSYNC(dir))
 			ntfs_sync_inode(dir);

 		if (IS_DIRSYNC(new_dir))
 			ntfs_sync_inode(inode);
 	}

 	ni_unlock(ni);
 	ni_unlock(dir_ni);
 out:
 	__putname(de);
 	return err;
 }

 struct dentry *ntfs3_get_parent(struct dentry *child)
 {
 	struct inode *inode = d_inode(child);
 	struct ntfs_inode *ni = ntfs_i(inode);

 	struct ATTR_LIST_ENTRY *le = NULL;
 	struct ATTRIB *attr = NULL;
 	struct ATTR_FILE_NAME *fname;

 	while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
 				    NULL))) {
 		fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
 		if (!fname)
 			continue;

 		return d_obtain_alias(
 			ntfs_iget5(inode->i_sb, &fname->home, NULL));
 	}

 	return ERR_PTR(-ENOENT);
 }

 // clang-format off
 const struct inode_operations ntfs_dir_inode_operations = {
 	.lookup		= ntfs_lookup,
 	.create		= ntfs_create,
 	.link		= ntfs_link,
 	.unlink		= ntfs_unlink,
 	.symlink	= ntfs_symlink,
 	.mkdir		= ntfs_mkdir,
 	.rmdir		= ntfs_rmdir,
 	.mknod		= ntfs_mknod,
 	.rename		= ntfs_rename,
 	.permission	= ntfs_permission,
 	.get_acl	= ntfs_get_acl,
 	.set_acl	= ntfs_set_acl,
 	.setattr	= ntfs3_setattr,
 	.getattr	= ntfs_getattr,
 	.listxattr	= ntfs_listxattr,
 	.fiemap		= ntfs_fiemap,
 };

 const struct inode_operations ntfs_special_inode_operations = {
 	.setattr	= ntfs3_setattr,
 	.getattr	= ntfs_getattr,
 	.listxattr	= ntfs_listxattr,
 	.get_acl	= ntfs_get_acl,
 	.set_acl	= ntfs_set_acl,
 };
 // clang-format on
	// SPDX-License-Identifier: GPL-2.0
	/*
	*
	* Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
	*
	*/

	#include <linux/fs.h>
	#include <linux/nls.h>

	#include "debug.h"
	#include "ntfs.h"
	#include "ntfs_fs.h"

	/*
	* fill_name_de - Format NTFS_DE in @buf.
	*/
	int fill_name_de(struct ntfs_sb_info sbi, void buf, const struct qstr *name,
	const struct cpu_str *uni)
	{
	int err;
	struct NTFS_DE *e = buf;
	u16 data_size;
	struct ATTR_FILE_NAME fname = (struct ATTR_FILE_NAME )(e + 1);

	#ifndef CONFIG_NTFS3_64BIT_CLUSTER
	e->ref.high = fname->home.high = 0;
	#endif
	if (uni) {
	#ifdef __BIG_ENDIAN
	int ulen = uni->len;
	__le16 *uname = fname->name;
	const u16 *name_cpu = uni->name;

	while (ulen--)
	uname++ = cpu_to_le16(name_cpu++);
	#else
	memcpy(fname->name, uni->name, uni->len * sizeof(u16));
	#endif
	fname->name_len = uni->len;

	} else {
	/* Convert input string to unicode. */
	err = ntfs_nls_to_utf16(sbi, name->name, name->len,
	(struct cpu_str *)&fname->name_len,
	NTFS_NAME_LEN, UTF16_LITTLE_ENDIAN);
	if (err < 0)
	return err;
	}

	fname->type = FILE_NAME_POSIX;
	data_size = fname_full_size(fname);

	e->size = cpu_to_le16(ALIGN(data_size, 8) + sizeof(struct NTFS_DE));
	e->key_size = cpu_to_le16(data_size);
	e->flags = 0;
	e->res = 0;

	return 0;
	}

	/*
	* ntfs_lookup - inode_operations::lookup
	*/
	static struct dentry ntfs_lookup(struct inode dir, struct dentry *dentry,
	u32 flags)
	{
	struct ntfs_inode *ni = ntfs_i(dir);
	struct cpu_str *uni = __getname();
	struct inode *inode;
	int err;

	if (!uni)
	inode = ERR_PTR(-ENOMEM);
	else {
	err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name,
	dentry->d_name.len, uni, NTFS_NAME_LEN,
	UTF16_HOST_ENDIAN);
	if (err < 0)
	inode = ERR_PTR(err);
	else {
	ni_lock(ni);
	inode = dir_search_u(dir, uni, NULL);
	ni_unlock(ni);
	}
	__putname(uni);
	}

	return d_splice_alias(inode, dentry);
	}

	/*
	* ntfs_create - inode_operations::create
	*/
	static int ntfs_create(struct user_namespace mnt_userns, struct inode dir,
	struct dentry *dentry, umode_t mode, bool excl)
	{
	struct inode *inode;

	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFREG \| mode,
	0, NULL, 0, NULL);

	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
	}

	/*
	* ntfs_mknod
	*
	* inode_operations::mknod
	*/
	static int ntfs_mknod(struct user_namespace mnt_userns, struct inode dir,
	struct dentry *dentry, umode_t mode, dev_t rdev)
	{
	struct inode *inode;

	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, mode, rdev,
	NULL, 0, NULL);

	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
	}

	/*
	* ntfs_link - inode_operations::link
	*/
	static int ntfs_link(struct dentry ode, struct inode dir, struct dentry *de)
	{
	int err;
	struct inode *inode = d_inode(ode);
	struct ntfs_inode *ni = ntfs_i(inode);

	if (S_ISDIR(inode->i_mode))
	return -EPERM;

	if (inode->i_nlink >= NTFS_LINK_MAX)
	return -EMLINK;

	ni_lock_dir(ntfs_i(dir));
	if (inode != dir)
	ni_lock(ni);

	inc_nlink(inode);
	ihold(inode);

	err = ntfs_link_inode(inode, de);

	if (!err) {
	dir->i_ctime = dir->i_mtime = inode->i_ctime =
	current_time(dir);
	mark_inode_dirty(inode);
	mark_inode_dirty(dir);
	d_instantiate(de, inode);
	} else {
	drop_nlink(inode);
	iput(inode);
	}

	if (inode != dir)
	ni_unlock(ni);
	ni_unlock(ntfs_i(dir));

	return err;
	}

	/*
	* ntfs_unlink - inode_operations::unlink
	*/
	static int ntfs_unlink(struct inode dir, struct dentry dentry)
	{
	struct ntfs_inode *ni = ntfs_i(dir);
	int err;

	ni_lock_dir(ni);

	err = ntfs_unlink_inode(dir, dentry);

	ni_unlock(ni);

	return err;
	}

	/*
	* ntfs_symlink - inode_operations::symlink
	*/
	static int ntfs_symlink(struct user_namespace mnt_userns, struct inode dir,
	struct dentry dentry, const char symname)
	{
	u32 size = strlen(symname);
	struct inode *inode;

	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFLNK \| 0777,
	0, symname, size, NULL);

	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
	}

	/*
	* ntfs_mkdir- inode_operations::mkdir
	*/
	static int ntfs_mkdir(struct user_namespace mnt_userns, struct inode dir,
	struct dentry *dentry, umode_t mode)
	{
	struct inode *inode;

	inode = ntfs_create_inode(mnt_userns, dir, dentry, NULL, S_IFDIR \| mode,
	0, NULL, 0, NULL);

	return IS_ERR(inode) ? PTR_ERR(inode) : 0;
	}

	/*
	* ntfs_rmdir - inode_operations::rm_dir
	*/
	static int ntfs_rmdir(struct inode dir, struct dentry dentry)
	{
	struct ntfs_inode *ni = ntfs_i(dir);
	int err;

	ni_lock_dir(ni);

	err = ntfs_unlink_inode(dir, dentry);

	ni_unlock(ni);

	return err;
	}

	/*
	* ntfs_rename - inode_operations::rename
	*/
	static int ntfs_rename(struct user_namespace mnt_userns, struct inode dir,
	struct dentry dentry, struct inode new_dir,
	struct dentry *new_dentry, u32 flags)
	{
	int err;
	struct super_block *sb = dir->i_sb;
	struct ntfs_sb_info *sbi = sb->s_fs_info;
	struct ntfs_inode *dir_ni = ntfs_i(dir);
	struct ntfs_inode *new_dir_ni = ntfs_i(new_dir);
	struct inode *inode = d_inode(dentry);
	struct ntfs_inode *ni = ntfs_i(inode);
	struct inode *new_inode = d_inode(new_dentry);
	struct NTFS_DE de, new_de;
	bool is_same, is_bad;
	/*
	* de - memory of PATH_MAX bytes:
	* [0-1024) - original name (dentry->d_name)
	* [1024-2048) - paired to original name, usually DOS variant of dentry->d_name
	* [2048-3072) - new name (new_dentry->d_name)
	*/
	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + SIZEOF_RESIDENT < 1024);
	static_assert(SIZEOF_ATTRIBUTE_FILENAME_MAX + sizeof(struct NTFS_DE) <
	1024);
	static_assert(PATH_MAX >= 4 * 1024);

	if (flags & ~RENAME_NOREPLACE)
	return -EINVAL;

	is_same = dentry->d_name.len == new_dentry->d_name.len &&
	!memcmp(dentry->d_name.name, new_dentry->d_name.name,
	dentry->d_name.len);

	if (is_same && dir == new_dir) {
	/* Nothing to do. */
	return 0;
	}

	if (ntfs_is_meta_file(sbi, inode->i_ino)) {
	/* Should we print an error? */
	return -EINVAL;
	}

	if (new_inode) {
	/* Target name exists. Unlink it. */
	dget(new_dentry);
	ni_lock_dir(new_dir_ni);
	err = ntfs_unlink_inode(new_dir, new_dentry);
	ni_unlock(new_dir_ni);
	dput(new_dentry);
	if (err)
	return err;
	}

	/* Allocate PATH_MAX bytes. */
	de = __getname();
	if (!de)
	return -ENOMEM;

	/* Translate dentry->d_name into unicode form. */
	err = fill_name_de(sbi, de, &dentry->d_name, NULL);
	if (err < 0)
	goto out;

	if (is_same) {
	/* Reuse 'de'. */
	new_de = de;
	} else {
	/* Translate new_dentry->d_name into unicode form. */
	new_de = Add2Ptr(de, 2048);
	err = fill_name_de(sbi, new_de, &new_dentry->d_name, NULL);
	if (err < 0)
	goto out;
	}

	ni_lock_dir(dir_ni);
	ni_lock(ni);

	is_bad = false;
	err = ni_rename(dir_ni, new_dir_ni, ni, de, new_de, &is_bad);
	if (is_bad) {
	/* Restore after failed rename failed too. */
	make_bad_inode(inode);
	ntfs_inode_err(inode, "failed to undo rename");
	ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
	} else if (!err) {
	inode->i_ctime = dir->i_ctime = dir->i_mtime =
	current_time(dir);
	mark_inode_dirty(inode);
	mark_inode_dirty(dir);
	if (dir != new_dir) {
	new_dir->i_mtime = new_dir->i_ctime = dir->i_ctime;
	mark_inode_dirty(new_dir);
	}

	if (IS_DIRSYNC(dir))
	ntfs_sync_inode(dir);

	if (IS_DIRSYNC(new_dir))
	ntfs_sync_inode(inode);
	}

	ni_unlock(ni);
	ni_unlock(dir_ni);
	out:
	__putname(de);
	return err;
	}

	struct dentry ntfs3_get_parent(struct dentry child)
	{
	struct inode *inode = d_inode(child);
	struct ntfs_inode *ni = ntfs_i(inode);

	struct ATTR_LIST_ENTRY *le = NULL;
	struct ATTRIB *attr = NULL;
	struct ATTR_FILE_NAME *fname;

	while ((attr = ni_find_attr(ni, attr, &le, ATTR_NAME, NULL, 0, NULL,
	NULL))) {
	fname = resident_data_ex(attr, SIZEOF_ATTRIBUTE_FILENAME);
	if (!fname)
	continue;

	return d_obtain_alias(
	ntfs_iget5(inode->i_sb, &fname->home, NULL));
	}

	return ERR_PTR(-ENOENT);
	}

	// clang-format off
	const struct inode_operations ntfs_dir_inode_operations = {
	.lookup = ntfs_lookup,
	.create = ntfs_create,
	.link = ntfs_link,
	.unlink = ntfs_unlink,
	.symlink = ntfs_symlink,
	.mkdir = ntfs_mkdir,
	.rmdir = ntfs_rmdir,
	.mknod = ntfs_mknod,
	.rename = ntfs_rename,
	.permission = ntfs_permission,
	.get_acl = ntfs_get_acl,
	.set_acl = ntfs_set_acl,
	.setattr = ntfs3_setattr,
	.getattr = ntfs_getattr,
	.listxattr = ntfs_listxattr,
	.fiemap = ntfs_fiemap,
	};

	const struct inode_operations ntfs_special_inode_operations = {
	.setattr = ntfs3_setattr,
	.getattr = ntfs_getattr,
	.listxattr = ntfs_listxattr,
	.get_acl = ntfs_get_acl,
	.set_acl = ntfs_set_acl,
	};
	// clang-format on