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ntfs: add reparse and ea operations

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Implement support for Extended Attributes and Reparse Points, enabling
Posix ACL support and, and compatibility with Windows Subsystem for
Linux (WSL) metadata.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This commit is contained in:
Namjae Jeon 2026-02-13 10:45:36 +09:00
parent 11ccc9107d
commit fc053f05ca
2 changed files with 1515 additions and 0 deletions
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942
fs/ntfs/ea.c Normal file
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@ -0,0 +1,942 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Pocessing of EA's
*
* Part of this file is based on code from the NTFS-3G.
*
* Copyright (c) 2014-2021 Jean-Pierre Andre
* Copyright (c) 2025 LG Electronics Co., Ltd.
*/
#include <linux/fs.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
#include "layout.h"
#include "attrib.h"
#include "index.h"
#include "dir.h"
#include "ea.h"
static int ntfs_write_ea(struct ntfs_inode *ni, __le32 type, char *value, s64 ea_off,
s64 ea_size, bool need_truncate)
{
struct inode *ea_vi;
int err = 0;
s64 written;
ea_vi = ntfs_attr_iget(VFS_I(ni), type, AT_UNNAMED, 0);
if (IS_ERR(ea_vi))
return PTR_ERR(ea_vi);
written = ntfs_inode_attr_pwrite(ea_vi, ea_off, ea_size, value, false);
if (written != ea_size)
err = -EIO;
else {
struct ntfs_inode *ea_ni = NTFS_I(ea_vi);
if (need_truncate && ea_ni->data_size > ea_off + ea_size)
ntfs_attr_truncate(ea_ni, ea_off + ea_size);
mark_mft_record_dirty(ni);
}
iput(ea_vi);
return err;
}
static int ntfs_ea_lookup(char *ea_buf, s64 ea_buf_size, const char *name,
int name_len, s64 *ea_offset, s64 *ea_size)
{
const struct ea_attr *p_ea;
s64 offset;
unsigned int next;
if (ea_buf_size < sizeof(struct ea_attr))
goto out;
offset = 0;
do {
p_ea = (const struct ea_attr *)&ea_buf[offset];
next = le32_to_cpu(p_ea->next_entry_offset);
if (offset + next > ea_buf_size ||
((1 + p_ea->ea_name_length) > (ea_buf_size - offset)))
break;
if (p_ea->ea_name_length == name_len &&
!memcmp(p_ea->ea_name, name, name_len)) {
*ea_offset = offset;
if (next)
*ea_size = next;
else {
unsigned int ea_len = 1 + p_ea->ea_name_length +
le16_to_cpu(p_ea->ea_value_length);
if ((ea_buf_size - offset) < ea_len)
goto out;
*ea_size = ALIGN(struct_size(p_ea, ea_name,
1 + p_ea->ea_name_length +
le16_to_cpu(p_ea->ea_value_length)), 4);
}
if (ea_buf_size < *ea_offset + *ea_size)
goto out;
return 0;
}
offset += next;
} while (next > 0 && offset < ea_buf_size &&
sizeof(struct ea_attr) < (ea_buf_size - offset));
out:
return -ENOENT;
}
/*
* Return the existing EA
*
* The EA_INFORMATION is not examined and the consistency of the
* existing EA is not checked.
*
* If successful, the full attribute is returned unchanged
* and its size is returned.
* If the designated buffer is too small, the needed size is
* returned, and the buffer is left unchanged.
* If there is an error, a negative value is returned and errno
* is set according to the error.
*/
static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
void *buffer, size_t size)
{
struct ntfs_inode *ni = NTFS_I(inode);
const struct ea_attr *p_ea;
char *ea_buf;
s64 ea_off, ea_size, all_ea_size, ea_info_size;
int err;
u32 ea_info_qlen;
u16 ea_value_len;
struct ea_information *p_ea_info;
if (!NInoHasEA(ni))
return -ENODATA;
p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
&ea_info_size);
if (!p_ea_info || ea_info_size != sizeof(struct ea_information)) {
kvfree(p_ea_info);
return -ENODATA;
}
ea_info_qlen = le32_to_cpu(p_ea_info->ea_query_length);
kvfree(p_ea_info);
ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
if (!ea_buf)
return -ENODATA;
err = ntfs_ea_lookup(ea_buf, ea_info_qlen, name, name_len, &ea_off,
&ea_size);
if (!err) {
p_ea = (struct ea_attr *)&ea_buf[ea_off];
ea_value_len = le16_to_cpu(p_ea->ea_value_length);
if (!buffer) {
kvfree(ea_buf);
return ea_value_len;
}
if (ea_value_len > size) {
err = -ERANGE;
goto free_ea_buf;
}
memcpy(buffer, &p_ea->ea_name[p_ea->ea_name_length + 1],
ea_value_len);
kvfree(ea_buf);
return ea_value_len;
}
err = -ENODATA;
free_ea_buf:
kvfree(ea_buf);
return err;
}
static inline int ea_packed_size(const struct ea_attr *p_ea)
{
/*
* 4 bytes for header (flags and lengths) + name length + 1 +
* value length.
*/
return 5 + p_ea->ea_name_length + le16_to_cpu(p_ea->ea_value_length);
}
/*
* Set a new EA, and set EA_INFORMATION accordingly
*
* This is roughly the same as ZwSetEaFile() on Windows, however
* the "offset to next" of the last EA should not be cleared.
*
* Consistency of the new EA is first checked.
*
* EA_INFORMATION is set first, and it is restored to its former
* state if setting EA fails.
*/
static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
const void *value, size_t val_size, int flags,
__le16 *packed_ea_size)
{
struct ntfs_inode *ni = NTFS_I(inode);
struct ea_information *p_ea_info = NULL;
int ea_packed, err = 0;
struct ea_attr *p_ea;
u32 ea_info_qsize = 0;
char *ea_buf = NULL;
size_t new_ea_size = ALIGN(struct_size(p_ea, ea_name, 1 + name_len + val_size), 4);
s64 ea_off, ea_info_size, all_ea_size, ea_size;
if (name_len > 255)
return -ENAMETOOLONG;
if (ntfs_attr_exist(ni, AT_EA_INFORMATION, AT_UNNAMED, 0)) {
p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
&ea_info_size);
if (!p_ea_info || ea_info_size != sizeof(struct ea_information))
goto out;
ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
if (!ea_buf) {
ea_info_qsize = 0;
kvfree(p_ea_info);
goto create_ea_info;
}
ea_info_qsize = le32_to_cpu(p_ea_info->ea_query_length);
} else {
create_ea_info:
p_ea_info = kzalloc(sizeof(struct ea_information), GFP_NOFS);
if (!p_ea_info)
return -ENOMEM;
ea_info_qsize = 0;
err = ntfs_attr_add(ni, AT_EA_INFORMATION, AT_UNNAMED, 0,
(char *)p_ea_info, sizeof(struct ea_information));
if (err)
goto out;
if (ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
err = ntfs_attr_remove(ni, AT_EA, AT_UNNAMED, 0);
if (err)
goto out;
}
goto alloc_new_ea;
}
if (ea_info_qsize > all_ea_size) {
err = -EIO;
goto out;
}
err = ntfs_ea_lookup(ea_buf, ea_info_qsize, name, name_len, &ea_off,
&ea_size);
if (ea_info_qsize && !err) {
if (flags & XATTR_CREATE) {
err = -EEXIST;
goto out;
}
p_ea = (struct ea_attr *)(ea_buf + ea_off);
if (val_size &&
le16_to_cpu(p_ea->ea_value_length) == val_size &&
!memcmp(p_ea->ea_name + p_ea->ea_name_length + 1, value,
val_size))
goto out;
le16_add_cpu(&p_ea_info->ea_length, 0 - ea_packed_size(p_ea));
if (p_ea->flags & NEED_EA)
le16_add_cpu(&p_ea_info->need_ea_count, -1);
memmove((char *)p_ea, (char *)p_ea + ea_size, ea_info_qsize - (ea_off + ea_size));
ea_info_qsize -= ea_size;
p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize);
err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info, 0,
sizeof(struct ea_information), false);
if (err)
goto out;
err = ntfs_write_ea(ni, AT_EA, ea_buf, 0, ea_info_qsize, true);
if (err)
goto out;
if ((flags & XATTR_REPLACE) && !val_size) {
/* Remove xattr. */
goto out;
}
} else {
if (flags & XATTR_REPLACE) {
err = -ENODATA;
goto out;
}
}
kvfree(ea_buf);
alloc_new_ea:
ea_buf = kzalloc(new_ea_size, GFP_NOFS);
if (!ea_buf) {
err = -ENOMEM;
goto out;
}
/*
* EA and REPARSE_POINT compatibility not checked any more,
* required by Windows 10, but having both may lead to
* problems with earlier versions.
*/
p_ea = (struct ea_attr *)ea_buf;
memcpy(p_ea->ea_name, name, name_len);
p_ea->ea_name_length = name_len;
p_ea->ea_name[name_len] = 0;
memcpy(p_ea->ea_name + name_len + 1, value, val_size);
p_ea->ea_value_length = cpu_to_le16(val_size);
p_ea->next_entry_offset = cpu_to_le32(new_ea_size);
ea_packed = le16_to_cpu(p_ea_info->ea_length) + ea_packed_size(p_ea);
p_ea_info->ea_length = cpu_to_le16(ea_packed);
p_ea_info->ea_query_length = cpu_to_le32(ea_info_qsize + new_ea_size);
if (ea_packed > 0xffff ||
ntfs_attr_size_bounds_check(ni->vol, AT_EA, new_ea_size)) {
err = -EFBIG;
goto out;
}
/*
* no EA or EA_INFORMATION : add them
*/
if (!ntfs_attr_exist(ni, AT_EA, AT_UNNAMED, 0)) {
err = ntfs_attr_add(ni, AT_EA, AT_UNNAMED, 0, (char *)p_ea,
new_ea_size);
if (err)
goto out;
} else {
err = ntfs_write_ea(ni, AT_EA, (char *)p_ea, ea_info_qsize,
new_ea_size, false);
if (err)
goto out;
}
err = ntfs_write_ea(ni, AT_EA_INFORMATION, (char *)p_ea_info, 0,
sizeof(struct ea_information), false);
if (err)
goto out;
if (packed_ea_size)
*packed_ea_size = p_ea_info->ea_length;
mark_mft_record_dirty(ni);
out:
if (ea_info_qsize > 0)
NInoSetHasEA(ni);
else
NInoClearHasEA(ni);
kvfree(ea_buf);
kvfree(p_ea_info);
return err;
}
/*
* Check for the presence of an EA "$LXDEV" (used by WSL)
* and return its value as a device address
*/
int ntfs_ea_get_wsl_inode(struct inode *inode, dev_t *rdevp, unsigned int flags)
{
int err;
__le32 v;
if (!(flags & NTFS_VOL_UID)) {
/* Load uid to lxuid EA */
err = ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
sizeof(v));
if (err < 0)
return err;
i_uid_write(inode, le32_to_cpu(v));
}
if (!(flags & NTFS_VOL_UID)) {
/* Load gid to lxgid EA */
err = ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
sizeof(v));
if (err < 0)
return err;
i_gid_write(inode, le32_to_cpu(v));
}
/* Load mode to lxmod EA */
err = ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v, sizeof(v));
if (err > 0) {
inode->i_mode = le32_to_cpu(v);
} else {
/* Everyone gets all permissions. */
inode->i_mode |= 0777;
}
/* Load mode to lxdev EA */
err = ntfs_get_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v));
if (err > 0)
*rdevp = le32_to_cpu(v);
err = 0;
return err;
}
int ntfs_ea_set_wsl_inode(struct inode *inode, dev_t rdev, __le16 *ea_size,
unsigned int flags)
{
__le32 v;
int err;
if (flags & NTFS_EA_UID) {
/* Store uid to lxuid EA */
v = cpu_to_le32(i_uid_read(inode));
err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &v,
sizeof(v), 0, ea_size);
if (err)
return err;
}
if (flags & NTFS_EA_GID) {
/* Store gid to lxgid EA */
v = cpu_to_le32(i_gid_read(inode));
err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &v,
sizeof(v), 0, ea_size);
if (err)
return err;
}
if (flags & NTFS_EA_MODE) {
/* Store mode to lxmod EA */
v = cpu_to_le32(inode->i_mode);
err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &v,
sizeof(v), 0, ea_size);
if (err)
return err;
}
if (rdev) {
v = cpu_to_le32(rdev);
err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &v, sizeof(v),
0, ea_size);
}
return err;
}
ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
struct inode *inode = d_inode(dentry);
struct ntfs_inode *ni = NTFS_I(inode);
const struct ea_attr *p_ea;
s64 offset, ea_buf_size, ea_info_size;
int next, err = 0, ea_size;
u32 ea_info_qsize;
char *ea_buf = NULL;
ssize_t ret = 0;
struct ea_information *ea_info;
if (!NInoHasEA(ni))
return 0;
mutex_lock(&NTFS_I(inode)->mrec_lock);
ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
&ea_info_size);
if (!ea_info || ea_info_size != sizeof(struct ea_information))
goto out;
ea_info_qsize = le32_to_cpu(ea_info->ea_query_length);
ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &ea_buf_size);
if (!ea_buf)
goto out;
if (ea_info_qsize > ea_buf_size)
goto out;
if (ea_buf_size < sizeof(struct ea_attr))
goto out;
offset = 0;
do {
p_ea = (const struct ea_attr *)&ea_buf[offset];
next = le32_to_cpu(p_ea->next_entry_offset);
if (next)
ea_size = next;
else
ea_size = ALIGN(struct_size(p_ea, ea_name,
1 + p_ea->ea_name_length +
le16_to_cpu(p_ea->ea_value_length)),
4);
if (buffer) {
if (offset + ea_size > ea_info_qsize)
break;
if (ret + p_ea->ea_name_length + 1 > size) {
err = -ERANGE;
goto out;
}
if (p_ea->ea_name_length + 1 > (ea_info_qsize - offset))
break;
memcpy(buffer + ret, p_ea->ea_name, p_ea->ea_name_length);
buffer[ret + p_ea->ea_name_length] = 0;
}
ret += p_ea->ea_name_length + 1;
offset += ea_size;
} while (next > 0 && offset < ea_info_qsize &&
sizeof(struct ea_attr) < (ea_info_qsize - offset));
out:
mutex_unlock(&NTFS_I(inode)->mrec_lock);
kvfree(ea_info);
kvfree(ea_buf);
return err ? err : ret;
}
// clang-format off
#define SYSTEM_DOS_ATTRIB "system.dos_attrib"
#define SYSTEM_NTFS_ATTRIB "system.ntfs_attrib"
#define SYSTEM_NTFS_ATTRIB_BE "system.ntfs_attrib_be"
// clang-format on
static int ntfs_getxattr(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode, const char *name,
void *buffer, size_t size)
{
struct ntfs_inode *ni = NTFS_I(inode);
int err;
if (NVolShutdown(ni->vol))
return -EIO;
if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
if (!buffer) {
err = sizeof(u8);
} else if (size < sizeof(u8)) {
err = -ENODATA;
} else {
err = sizeof(u8);
*(u8 *)buffer = (u8)(le32_to_cpu(ni->flags) & 0x3F);
}
goto out;
}
if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
!strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
if (!buffer) {
err = sizeof(u32);
} else if (size < sizeof(u32)) {
err = -ENODATA;
} else {
err = sizeof(u32);
*(u32 *)buffer = le32_to_cpu(ni->flags);
if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
}
goto out;
}
mutex_lock(&ni->mrec_lock);
err = ntfs_get_ea(inode, name, strlen(name), buffer, size);
mutex_unlock(&ni->mrec_lock);
out:
return err;
}
static int ntfs_new_attr_flags(struct ntfs_inode *ni, __le32 fattr)
{
struct ntfs_attr_search_ctx *ctx;
struct mft_record *m;
struct attr_record *a;
__le16 new_aflags;
int mp_size, mp_ofs, name_ofs, arec_size, err;
m = map_mft_record(ni);
if (IS_ERR(m))
return PTR_ERR(m);
ctx = ntfs_attr_get_search_ctx(ni, m);
if (!ctx) {
err = -ENOMEM;
goto err_out;
}
err = ntfs_attr_lookup(ni->type, ni->name, ni->name_len,
CASE_SENSITIVE, 0, NULL, 0, ctx);
if (err) {
err = -EINVAL;
goto err_out;
}
a = ctx->attr;
new_aflags = ctx->attr->flags;
if (fattr & FILE_ATTR_SPARSE_FILE)
new_aflags |= ATTR_IS_SPARSE;
else
new_aflags &= ~ATTR_IS_SPARSE;
if (fattr & FILE_ATTR_COMPRESSED)
new_aflags |= ATTR_IS_COMPRESSED;
else
new_aflags &= ~ATTR_IS_COMPRESSED;
if (new_aflags == a->flags)
return 0;
if ((new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) ==
(ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
pr_err("file can't be sparsed and compressed\n");
err = -EOPNOTSUPP;
goto err_out;
}
if (!a->non_resident)
goto out;
if (a->data.non_resident.data_size) {
pr_err("Can't change sparsed/compressed for non-empty file");
err = -EOPNOTSUPP;
goto err_out;
}
if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED))
name_ofs = (offsetof(struct attr_record,
data.non_resident.compressed_size) +
sizeof(a->data.non_resident.compressed_size) + 7) & ~7;
else
name_ofs = (offsetof(struct attr_record,
data.non_resident.compressed_size) + 7) & ~7;
mp_size = ntfs_get_size_for_mapping_pairs(ni->vol, ni->runlist.rl, 0, -1, -1);
if (unlikely(mp_size < 0)) {
err = mp_size;
ntfs_debug("Failed to get size for mapping pairs array, error code %i.\n", err);
goto err_out;
}
mp_ofs = (name_ofs + a->name_length * sizeof(__le16) + 7) & ~7;
arec_size = (mp_ofs + mp_size + 7) & ~7;
err = ntfs_attr_record_resize(m, a, arec_size);
if (unlikely(err))
goto err_out;
if (new_aflags & (ATTR_IS_SPARSE | ATTR_IS_COMPRESSED)) {
a->data.non_resident.compression_unit = 0;
if (new_aflags & ATTR_IS_COMPRESSED || ni->vol->major_ver < 3)
a->data.non_resident.compression_unit = 4;
a->data.non_resident.compressed_size = 0;
ni->itype.compressed.size = 0;
if (a->data.non_resident.compression_unit) {
ni->itype.compressed.block_size = 1U <<
(a->data.non_resident.compression_unit +
ni->vol->cluster_size_bits);
ni->itype.compressed.block_size_bits =
ffs(ni->itype.compressed.block_size) -
1;
ni->itype.compressed.block_clusters = 1U <<
a->data.non_resident.compression_unit;
} else {
ni->itype.compressed.block_size = 0;
ni->itype.compressed.block_size_bits = 0;
ni->itype.compressed.block_clusters = 0;
}
if (new_aflags & ATTR_IS_SPARSE) {
NInoSetSparse(ni);
ni->flags |= FILE_ATTR_SPARSE_FILE;
}
if (new_aflags & ATTR_IS_COMPRESSED) {
NInoSetCompressed(ni);
ni->flags |= FILE_ATTR_COMPRESSED;
}
} else {
ni->flags &= ~(FILE_ATTR_SPARSE_FILE | FILE_ATTR_COMPRESSED);
a->data.non_resident.compression_unit = 0;
NInoClearSparse(ni);
NInoClearCompressed(ni);
}
a->name_offset = cpu_to_le16(name_ofs);
a->data.non_resident.mapping_pairs_offset = cpu_to_le16(mp_ofs);
out:
a->flags = new_aflags;
mark_mft_record_dirty(ctx->ntfs_ino);
err_out:
ntfs_attr_put_search_ctx(ctx);
unmap_mft_record(ni);
return err;
}
static int ntfs_setxattr(const struct xattr_handler *handler,
struct mnt_idmap *idmap, struct dentry *unused,
struct inode *inode, const char *name, const void *value,
size_t size, int flags)
{
struct ntfs_inode *ni = NTFS_I(inode);
int err;
__le32 fattr;
if (NVolShutdown(ni->vol))
return -EIO;
if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
if (sizeof(u8) != size) {
err = -EINVAL;
goto out;
}
fattr = cpu_to_le32(*(u8 *)value);
goto set_fattr;
}
if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
!strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
if (size != sizeof(u32)) {
err = -EINVAL;
goto out;
}
if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
fattr = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
else
fattr = cpu_to_le32(*(u32 *)value);
if (S_ISREG(inode->i_mode)) {
mutex_lock(&ni->mrec_lock);
err = ntfs_new_attr_flags(ni, fattr);
mutex_unlock(&ni->mrec_lock);
if (err)
goto out;
}
set_fattr:
if (S_ISDIR(inode->i_mode))
fattr |= FILE_ATTR_DIRECTORY;
else
fattr &= ~FILE_ATTR_DIRECTORY;
if (ni->flags != fattr) {
ni->flags = fattr;
if (fattr & FILE_ATTR_READONLY)
inode->i_mode &= ~0222;
else
inode->i_mode |= 0222;
NInoSetFileNameDirty(ni);
mark_inode_dirty(inode);
}
err = 0;
goto out;
}
mutex_lock(&ni->mrec_lock);
err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, NULL);
mutex_unlock(&ni->mrec_lock);
out:
inode_set_ctime_current(inode);
mark_inode_dirty(inode);
return err;
}
static bool ntfs_xattr_user_list(struct dentry *dentry)
{
return true;
}
// clang-format off
static const struct xattr_handler ntfs_other_xattr_handler = {
.prefix = "",
.get = ntfs_getxattr,
.set = ntfs_setxattr,
.list = ntfs_xattr_user_list,
};
const struct xattr_handler * const ntfs_xattr_handlers[] = {
&ntfs_other_xattr_handler,
NULL,
};
// clang-format on
#ifdef CONFIG_NTFS_FS_POSIX_ACL
struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
int type)
{
struct inode *inode = d_inode(dentry);
struct ntfs_inode *ni = NTFS_I(inode);
const char *name;
size_t name_len;
struct posix_acl *acl;
int err;
void *buf;
buf = kmalloc(PATH_MAX, GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
/* Possible values of 'type' was already checked above. */
if (type == ACL_TYPE_ACCESS) {
name = XATTR_NAME_POSIX_ACL_ACCESS;
name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
} else {
name = XATTR_NAME_POSIX_ACL_DEFAULT;
name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
}
mutex_lock(&ni->mrec_lock);
err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX);
mutex_unlock(&ni->mrec_lock);
/* Translate extended attribute to acl. */
if (err >= 0)
acl = posix_acl_from_xattr(&init_user_ns, buf, err);
else if (err == -ENODATA)
acl = NULL;
else
acl = ERR_PTR(err);
if (!IS_ERR(acl))
set_cached_acl(inode, type, acl);
kfree(buf);
return acl;
}
static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
struct inode *inode, struct posix_acl *acl,
int type, bool init_acl)
{
const char *name;
size_t size, name_len;
void *value;
int err;
int flags;
umode_t mode;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
mode = inode->i_mode;
switch (type) {
case ACL_TYPE_ACCESS:
/* Do not change i_mode if we are in init_acl */
if (acl && !init_acl) {
err = posix_acl_update_mode(idmap, inode, &mode, &acl);
if (err)
return err;
}
name = XATTR_NAME_POSIX_ACL_ACCESS;
name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode))
return acl ? -EACCES : 0;
name = XATTR_NAME_POSIX_ACL_DEFAULT;
name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
break;
default:
return -EINVAL;
}
if (!acl) {
/* Remove xattr if it can be presented via mode. */
size = 0;
value = NULL;
flags = XATTR_REPLACE;
} else {
value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS);
if (!value)
return -ENOMEM;
flags = 0;
}
mutex_lock(&NTFS_I(inode)->mrec_lock);
err = ntfs_set_ea(inode, name, name_len, value, size, flags, NULL);
mutex_unlock(&NTFS_I(inode)->mrec_lock);
if (err == -ENODATA && !size)
err = 0; /* Removing non existed xattr. */
if (!err) {
__le16 ea_size = 0;
umode_t old_mode = inode->i_mode;
inode->i_mode = mode;
mutex_lock(&NTFS_I(inode)->mrec_lock);
err = ntfs_ea_set_wsl_inode(inode, 0, &ea_size, NTFS_EA_MODE);
if (err) {
ntfs_set_ea(inode, name, name_len, NULL, 0,
XATTR_REPLACE, NULL);
mutex_unlock(&NTFS_I(inode)->mrec_lock);
inode->i_mode = old_mode;
goto out;
}
mutex_unlock(&NTFS_I(inode)->mrec_lock);
set_cached_acl(inode, type, acl);
inode_set_ctime_current(inode);
mark_inode_dirty(inode);
}
out:
kfree(value);
return err;
}
int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
struct posix_acl *acl, int type)
{
return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
}
int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
struct inode *dir)
{
struct posix_acl *default_acl, *acl;
int err;
err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
if (err)
return err;
if (default_acl) {
err = ntfs_set_acl_ex(idmap, inode, default_acl,
ACL_TYPE_DEFAULT, true);
posix_acl_release(default_acl);
} else {
inode->i_default_acl = NULL;
}
if (acl) {
if (!err)
err = ntfs_set_acl_ex(idmap, inode, acl,
ACL_TYPE_ACCESS, true);
posix_acl_release(acl);
} else {
inode->i_acl = NULL;
}
return err;
}
#endif

573
fs/ntfs/reparse.c Normal file
View File

@ -0,0 +1,573 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Processing of reparse points
*
* Part of this file is based on code from the NTFS-3G.
*
* Copyright (c) 2008-2021 Jean-Pierre Andre
* Copyright (c) 2025 LG Electronics Co., Ltd.
*/
#include "ntfs.h"
#include "layout.h"
#include "attrib.h"
#include "inode.h"
#include "dir.h"
#include "volume.h"
#include "mft.h"
#include "index.h"
#include "lcnalloc.h"
#include "reparse.h"
struct wsl_link_reparse_data {
__le32 type;
char link[];
};
/* Index entry in $Extend/$Reparse */
struct reparse_index {
struct index_entry_header header;
struct reparse_index_key key;
__le32 filling;
};
__le16 reparse_index_name[] = {cpu_to_le16('$'), cpu_to_le16('R'), 0};
/*
* Check if the reparse point attribute buffer is valid.
* Returns true if valid, false otherwise.
*/
static bool ntfs_is_valid_reparse_buffer(struct ntfs_inode *ni,
const struct reparse_point *reparse_attr, size_t size)
{
size_t expected;
if (!ni || !reparse_attr)
return false;
/* Minimum size must cover reparse_point header */
if (size < sizeof(struct reparse_point))
return false;
/* Reserved zero tag is invalid */
if (reparse_attr->reparse_tag == IO_REPARSE_TAG_RESERVED_ZERO)
return false;
/* Calculate expected total size */
expected = sizeof(struct reparse_point) +
le16_to_cpu(reparse_attr->reparse_data_length);
/* Add GUID size for non-Microsoft tags */
if (!(reparse_attr->reparse_tag & IO_REPARSE_TAG_IS_MICROSOFT))
expected += sizeof(struct guid);
/* Buffer must exactly match the expected size */
return expected == size;
}
/*
* Do some sanity checks on reparse data
*
* Microsoft reparse points have an 8-byte header whereas
* non-Microsoft reparse points have a 24-byte header. In each case,
* 'reparse_data_length' must equal the number of non-header bytes.
*
* If the reparse data looks like a junction point or symbolic
* link, more checks can be done.
*/
static bool valid_reparse_data(struct ntfs_inode *ni,
const struct reparse_point *reparse_attr, size_t size)
{
const struct wsl_link_reparse_data *wsl_reparse_data =
(const struct wsl_link_reparse_data *)reparse_attr->reparse_data;
unsigned int data_len = le16_to_cpu(reparse_attr->reparse_data_length);
if (ntfs_is_valid_reparse_buffer(ni, reparse_attr, size) == false)
return false;
switch (reparse_attr->reparse_tag) {
case IO_REPARSE_TAG_LX_SYMLINK:
if (data_len <= sizeof(wsl_reparse_data->type) ||
wsl_reparse_data->type != cpu_to_le32(2))
return false;
break;
case IO_REPARSE_TAG_AF_UNIX:
case IO_REPARSE_TAG_LX_FIFO:
case IO_REPARSE_TAG_LX_CHR:
case IO_REPARSE_TAG_LX_BLK:
if (data_len || !(ni->flags & FILE_ATTRIBUTE_RECALL_ON_OPEN))
return false;
}
return true;
}
static unsigned int ntfs_reparse_tag_mode(struct reparse_point *reparse_attr)
{
unsigned int mode = 0;
switch (reparse_attr->reparse_tag) {
case IO_REPARSE_TAG_SYMLINK:
case IO_REPARSE_TAG_LX_SYMLINK:
mode = S_IFLNK;
break;
case IO_REPARSE_TAG_AF_UNIX:
mode = S_IFSOCK;
break;
case IO_REPARSE_TAG_LX_FIFO:
mode = S_IFIFO;
break;
case IO_REPARSE_TAG_LX_CHR:
mode = S_IFCHR;
break;
case IO_REPARSE_TAG_LX_BLK:
mode = S_IFBLK;
}
return mode;
}
/*
* Get the target for symbolic link
*/
unsigned int ntfs_make_symlink(struct ntfs_inode *ni)
{
s64 attr_size = 0;
unsigned int lth;
struct reparse_point *reparse_attr;
struct wsl_link_reparse_data *wsl_link_data;
unsigned int mode = 0;
reparse_attr = ntfs_attr_readall(ni, AT_REPARSE_POINT, NULL, 0,
&attr_size);
if (reparse_attr && attr_size &&
valid_reparse_data(ni, reparse_attr, attr_size)) {
switch (reparse_attr->reparse_tag) {
case IO_REPARSE_TAG_LX_SYMLINK:
wsl_link_data =
(struct wsl_link_reparse_data *)reparse_attr->reparse_data;
if (wsl_link_data->type == cpu_to_le32(2)) {
lth = le16_to_cpu(reparse_attr->reparse_data_length) -
sizeof(wsl_link_data->type);
ni->target = kvzalloc(lth + 1, GFP_NOFS);
if (ni->target) {
memcpy(ni->target, wsl_link_data->link, lth);
ni->target[lth] = 0;
mode = ntfs_reparse_tag_mode(reparse_attr);
}
}
break;
default:
mode = ntfs_reparse_tag_mode(reparse_attr);
}
} else
ni->flags &= ~FILE_ATTR_REPARSE_POINT;
if (reparse_attr)
kvfree(reparse_attr);
return mode;
}
unsigned int ntfs_reparse_tag_dt_types(struct ntfs_volume *vol, unsigned long mref)
{
s64 attr_size = 0;
struct reparse_point *reparse_attr;
unsigned int dt_type = DT_UNKNOWN;
struct inode *vi;
vi = ntfs_iget(vol->sb, mref);
if (IS_ERR(vi))
return PTR_ERR(vi);
reparse_attr = (struct reparse_point *)ntfs_attr_readall(NTFS_I(vi),
AT_REPARSE_POINT, NULL, 0, &attr_size);
if (reparse_attr && attr_size) {
switch (reparse_attr->reparse_tag) {
case IO_REPARSE_TAG_SYMLINK:
case IO_REPARSE_TAG_LX_SYMLINK:
dt_type = DT_LNK;
break;
case IO_REPARSE_TAG_AF_UNIX:
dt_type = DT_SOCK;
break;
case IO_REPARSE_TAG_LX_FIFO:
dt_type = DT_FIFO;
break;
case IO_REPARSE_TAG_LX_CHR:
dt_type = DT_CHR;
break;
case IO_REPARSE_TAG_LX_BLK:
dt_type = DT_BLK;
}
}
if (reparse_attr)
kvfree(reparse_attr);
iput(vi);
return dt_type;
}
/*
* Set the index for new reparse data
*/
static int set_reparse_index(struct ntfs_inode *ni, struct ntfs_index_context *xr,
__le32 reparse_tag)
{
struct reparse_index indx;
u64 file_id_cpu;
__le64 file_id;
file_id_cpu = MK_MREF(ni->mft_no, ni->seq_no);
file_id = cpu_to_le64(file_id_cpu);
indx.header.data.vi.data_offset =
cpu_to_le16(sizeof(struct index_entry_header) + sizeof(struct reparse_index_key));
indx.header.data.vi.data_length = 0;
indx.header.data.vi.reservedV = 0;
indx.header.length = cpu_to_le16(sizeof(struct reparse_index));
indx.header.key_length = cpu_to_le16(sizeof(struct reparse_index_key));
indx.header.flags = 0;
indx.header.reserved = 0;
indx.key.reparse_tag = reparse_tag;
/* danger on processors which require proper alignment! */
memcpy(&indx.key.file_id, &file_id, 8);
indx.filling = 0;
ntfs_index_ctx_reinit(xr);
return ntfs_ie_add(xr, (struct index_entry *)&indx);
}
/*
* Remove a reparse data index entry if attribute present
*/
static int remove_reparse_index(struct inode *rp, struct ntfs_index_context *xr,
__le32 *preparse_tag)
{
struct reparse_index_key key;
u64 file_id_cpu;
__le64 file_id;
s64 size;
struct ntfs_inode *ni = NTFS_I(rp);
int err = 0, ret = ni->data_size;
if (ni->data_size == 0)
return 0;
/* read the existing reparse_tag */
size = ntfs_inode_attr_pread(rp, 0, 4, (char *)preparse_tag);
if (size != 4)
return -ENODATA;
file_id_cpu = MK_MREF(ni->mft_no, ni->seq_no);
file_id = cpu_to_le64(file_id_cpu);
key.reparse_tag = *preparse_tag;
/* danger on processors which require proper alignment! */
memcpy(&key.file_id, &file_id, 8);
if (!ntfs_index_lookup(&key, sizeof(struct reparse_index_key), xr)) {
err = ntfs_index_rm(xr);
if (err)
ret = err;
}
return ret;
}
/*
* Open the $Extend/$Reparse file and its index
*/
static struct ntfs_index_context *open_reparse_index(struct ntfs_volume *vol)
{
struct ntfs_index_context *xr = NULL;
u64 mref;
__le16 *uname;
struct ntfs_name *name = NULL;
int uname_len;
struct inode *vi, *dir_vi;
/* do not use path_name_to inode - could reopen root */
dir_vi = ntfs_iget(vol->sb, FILE_Extend);
if (IS_ERR(dir_vi))
return NULL;
uname_len = ntfs_nlstoucs(vol, "$Reparse", 8, &uname,
NTFS_MAX_NAME_LEN);
if (uname_len < 0) {
iput(dir_vi);
return NULL;
}
mutex_lock_nested(&NTFS_I(dir_vi)->mrec_lock, NTFS_EXTEND_MUTEX_PARENT);
mref = ntfs_lookup_inode_by_name(NTFS_I(dir_vi), uname, uname_len,
&name);
mutex_unlock(&NTFS_I(dir_vi)->mrec_lock);
kfree(name);
kmem_cache_free(ntfs_name_cache, uname);
if (IS_ERR_MREF(mref))
goto put_dir_vi;
vi = ntfs_iget(vol->sb, MREF(mref));
if (IS_ERR(vi))
goto put_dir_vi;
xr = ntfs_index_ctx_get(NTFS_I(vi), reparse_index_name, 2);
if (!xr)
iput(vi);
put_dir_vi:
iput(dir_vi);
return xr;
}
/*
* Update the reparse data and index
*
* The reparse data attribute should have been created, and
* an existing index is expected if there is an existing value.
*
*/
static int update_reparse_data(struct ntfs_inode *ni, struct ntfs_index_context *xr,
char *value, size_t size)
{
struct inode *rp_inode;
int err = 0;
s64 written;
int oldsize;
__le32 reparse_tag;
struct ntfs_inode *rp_ni;
rp_inode = ntfs_attr_iget(VFS_I(ni), AT_REPARSE_POINT, AT_UNNAMED, 0);
if (IS_ERR(rp_inode))
return -EINVAL;
rp_ni = NTFS_I(rp_inode);
/* remove the existing reparse data */
oldsize = remove_reparse_index(rp_inode, xr, &reparse_tag);
if (oldsize < 0) {
err = oldsize;
goto put_rp_inode;
}
/* overwrite value if any */
written = ntfs_inode_attr_pwrite(rp_inode, 0, size, value, false);
if (written != size) {
ntfs_error(ni->vol->sb, "Failed to update reparse data\n");
err = -EIO;
goto put_rp_inode;
}
if (set_reparse_index(ni, xr, ((const struct reparse_point *)value)->reparse_tag) &&
oldsize > 0) {
/*
* If cannot index, try to remove the reparse
* data and log the error. There will be an
* inconsistency if removal fails.
*/
ntfs_attr_rm(rp_ni);
ntfs_error(ni->vol->sb,
"Failed to index reparse data. Possible corruption.\n");
}
mark_mft_record_dirty(ni);
put_rp_inode:
iput(rp_inode);
return err;
}
/*
* Delete a reparse index entry
*/
int ntfs_delete_reparse_index(struct ntfs_inode *ni)
{
struct inode *vi;
struct ntfs_index_context *xr;
struct ntfs_inode *xrni;
__le32 reparse_tag;
int err = 0;
if (!(ni->flags & FILE_ATTR_REPARSE_POINT))
return 0;
vi = ntfs_attr_iget(VFS_I(ni), AT_REPARSE_POINT, AT_UNNAMED, 0);
if (IS_ERR(vi))
return PTR_ERR(vi);
/*
* read the existing reparse data (the tag is enough)
* and un-index it
*/
xr = open_reparse_index(ni->vol);
if (xr) {
xrni = xr->idx_ni;
mutex_lock_nested(&xrni->mrec_lock, NTFS_EXTEND_MUTEX_PARENT);
err = remove_reparse_index(vi, xr, &reparse_tag);
if (err < 0) {
ntfs_index_ctx_put(xr);
mutex_unlock(&xrni->mrec_lock);
iput(VFS_I(xrni));
goto out;
}
mark_mft_record_dirty(xrni);
ntfs_index_ctx_put(xr);
mutex_unlock(&xrni->mrec_lock);
iput(VFS_I(xrni));
}
ni->flags &= ~FILE_ATTR_REPARSE_POINT;
NInoSetFileNameDirty(ni);
mark_mft_record_dirty(ni);
out:
iput(vi);
return err;
}
/*
* Set the reparse data from an extended attribute
*/
static int ntfs_set_ntfs_reparse_data(struct ntfs_inode *ni, char *value, size_t size)
{
int err = 0;
struct ntfs_inode *xrni;
struct ntfs_index_context *xr;
if (!ni)
return -EINVAL;
/*
* reparse data compatibily with EA is not checked
* any more, it is required by Windows 10, but may
* lead to problems with earlier versions.
*/
if (valid_reparse_data(ni, (const struct reparse_point *)value, size) == false)
return -EINVAL;
xr = open_reparse_index(ni->vol);
if (!xr)
return -EINVAL;
xrni = xr->idx_ni;
if (!ntfs_attr_exist(ni, AT_REPARSE_POINT, AT_UNNAMED, 0)) {
u8 dummy = 0;
/*
* no reparse data attribute : add one,
* apparently, this does not feed the new value in
* Note : NTFS version must be >= 3
*/
if (ni->vol->major_ver < 3) {
err = -EOPNOTSUPP;
ntfs_index_ctx_put(xr);
goto out;
}
err = ntfs_attr_add(ni, AT_REPARSE_POINT, AT_UNNAMED, 0, &dummy, 0);
if (err) {
ntfs_index_ctx_put(xr);
goto out;
}
ni->flags |= FILE_ATTR_REPARSE_POINT;
NInoSetFileNameDirty(ni);
mark_mft_record_dirty(ni);
}
/* update value and index */
mutex_lock_nested(&xrni->mrec_lock, NTFS_EXTEND_MUTEX_PARENT);
err = update_reparse_data(ni, xr, value, size);
if (err) {
ni->flags &= ~FILE_ATTR_REPARSE_POINT;
NInoSetFileNameDirty(ni);
mark_mft_record_dirty(ni);
}
ntfs_index_ctx_put(xr);
mutex_unlock(&xrni->mrec_lock);
out:
if (!err)
mark_mft_record_dirty(xrni);
iput(VFS_I(xrni));
return err;
}
/*
* Set reparse data for a WSL type symlink
*/
int ntfs_reparse_set_wsl_symlink(struct ntfs_inode *ni,
const __le16 *target, int target_len)
{
int err = 0;
int len;
int reparse_len;
unsigned char *utarget = NULL;
struct reparse_point *reparse;
struct wsl_link_reparse_data *data;
utarget = (char *)NULL;
len = ntfs_ucstonls(ni->vol, target, target_len, &utarget, 0);
if (len <= 0)
return -EINVAL;
reparse_len = sizeof(struct reparse_point) + sizeof(data->type) + len;
reparse = kvzalloc(reparse_len, GFP_NOFS);
if (!reparse) {
err = -ENOMEM;
kvfree(utarget);
} else {
data = (struct wsl_link_reparse_data *)reparse->reparse_data;
reparse->reparse_tag = IO_REPARSE_TAG_LX_SYMLINK;
reparse->reparse_data_length =
cpu_to_le16(sizeof(data->type) + len);
reparse->reserved = 0;
data->type = cpu_to_le32(2);
memcpy(data->link, utarget, len);
err = ntfs_set_ntfs_reparse_data(ni,
(char *)reparse, reparse_len);
kvfree(reparse);
if (!err)
ni->target = utarget;
}
return err;
}
/*
* Set reparse data for a WSL special file other than a symlink
* (socket, fifo, character or block device)
*/
int ntfs_reparse_set_wsl_not_symlink(struct ntfs_inode *ni, mode_t mode)
{
int err;
int len;
int reparse_len;
__le32 reparse_tag;
struct reparse_point *reparse;
len = 0;
if (S_ISSOCK(mode))
reparse_tag = IO_REPARSE_TAG_AF_UNIX;
else if (S_ISFIFO(mode))
reparse_tag = IO_REPARSE_TAG_LX_FIFO;
else if (S_ISCHR(mode))
reparse_tag = IO_REPARSE_TAG_LX_CHR;
else if (S_ISBLK(mode))
reparse_tag = IO_REPARSE_TAG_LX_BLK;
else
return -EOPNOTSUPP;
reparse_len = sizeof(struct reparse_point) + len;
reparse = kvzalloc(reparse_len, GFP_NOFS);
if (!reparse)
err = -ENOMEM;
else {
reparse->reparse_tag = reparse_tag;
reparse->reparse_data_length = cpu_to_le16(len);
reparse->reserved = cpu_to_le16(0);
err = ntfs_set_ntfs_reparse_data(ni, (char *)reparse,
reparse_len);
kvfree(reparse);
}
return err;
}