linux-stable/fs/ntfs3/namei.c
Konstantin Komarov d562e901f2
fs/ntfs3: Move ni_lock_dir and ni_unlock into ntfs_create_inode
Now ntfs3 locks mutex for smaller time.
Theoretically in successful cases those locks aren't needed at all.
But proving the same for error cases is difficult.
So instead of removing them we just move them.

Reviewed-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-09-24 17:39:57 +03:00

387 lines
8.4 KiB
C

// 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