lisa/android_kernel_xiaomi_sm8350
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

exfat: add ioctls for accessing attributes

Browse Source 
Add GET and SET attributes ioctls to enable attribute modification.
We already do this in FAT and a few userspace utils made for it would
benefit from this also working on exFAT, namely fatattr.

Signed-off-by: Jan Cincera <hcincera@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This commit is contained in:
Jan Cincera 2023-09-04 11:05:23 +09:00 committed by Namjae Jeon
parent 967fa6b9d1
commit cc9879a6ce
2 changed files with 138 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
exfat_fs.h
View File

@ -162,6 +162,12 @@ enum {
#define DIR_CACHE_SIZE \
(DIV_ROUND_UP(EXFAT_DEN_TO_B(ES_MAX_ENTRY_NUM), SECTOR_SIZE) + 1)
/*
* attribute ioctls, same as their FAT equivalents.
*/
#define EXFAT_IOCTL_GET_ATTRIBUTES _IOR('r', 0x10, __u32)
#define EXFAT_IOCTL_SET_ATTRIBUTES _IOW('r', 0x11, __u32)
struct exfat_dentry_namebuf {
char *lfn;
int lfnbuf_len; /* usually MAX_UNINAME_BUF_SIZE */

132
file.c
View File

@ -9,8 +9,11 @@
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#include <linux/cred.h>
#endif
#include <linux/mount.h>
#include <linux/compat.h>
#include <linux/blkdev.h>
#include <linux/fsnotify.h>
#include <linux/security.h>
#include "exfat_raw.h"
#include "exfat_fs.h"
@ -390,6 +393,130 @@ out:
return error;
}
/*
* modified ioctls from fat/file.c by Welmer Almesberger
*/
static int exfat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
{
u32 attr;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
inode_lock_shared(inode);
#else
mutex_lock(&inode->i_mutex);
#endif
attr = exfat_make_attr(inode);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
inode_unlock_shared(inode);
#else
mutex_unlock(&inode->i_mutex);
#endif
return put_user(attr, user_attr);
}
static int exfat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
{
struct inode *inode = file_inode(file);
struct exfat_sb_info *sbi = EXFAT_SB(inode->i_sb);
int is_dir = S_ISDIR(inode->i_mode);
u32 attr, oldattr;
struct iattr ia;
int err;
err = get_user(attr, user_attr);
if (err)
goto out;
err = mnt_want_write_file(file);
if (err)
goto out;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
inode_lock(inode);
#else
mutex_lock(&inode->i_mutex);
#endif
oldattr = exfat_make_attr(inode);
/*
* Mask attributes so we don't set reserved fields.
*/
attr &= (ATTR_READONLY | ATTR_HIDDEN | ATTR_SYSTEM | ATTR_ARCHIVE);
attr |= (is_dir ? ATTR_SUBDIR : 0);
/* Equivalent to a chmod() */
ia.ia_valid = ATTR_MODE | ATTR_CTIME;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
ia.ia_ctime = current_time(inode);
#else
ia.ia_ctime = current_fs_time(inode->i_sb);
#endif
if (is_dir)
ia.ia_mode = exfat_make_mode(sbi, attr, 0777);
else
ia.ia_mode = exfat_make_mode(sbi, attr, 0666 | (inode->i_mode & 0111));
/* The root directory has no attributes */
if (inode->i_ino == EXFAT_ROOT_INO && attr != ATTR_SUBDIR) {
err = -EINVAL;
goto out_unlock_inode;
}
if (((attr | oldattr) & ATTR_SYSTEM) &&
!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock_inode;
}
/*
* The security check is questionable... We single
* out the RO attribute for checking by the security
* module, just because it maps to a file mode.
*/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 0, 0)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
err = security_inode_setattr(file_mnt_idmap(file),
file->f_path.dentry, &ia);
#else
err = security_inode_setattr(file_mnt_user_ns(file),
file->f_path.dentry, &ia);
#endif
#else
err = security_inode_setattr(file->f_path.dentry, &ia);
#endif
if (err)
goto out_unlock_inode;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 12, 0)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 3, 0)
/* This MUST be done before doing anything irreversible... */
err = exfat_setattr(file_mnt_idmap(file), file->f_path.dentry, &ia);
#else
err = exfat_setattr(file_mnt_user_ns(file), file->f_path.dentry, &ia);
#endif
#else
err = exfat_setattr(file->f_path.dentry, &ia);
#endif
if (err)
goto out_unlock_inode;
fsnotify_change(file->f_path.dentry, ia.ia_valid);
exfat_save_attr(inode, attr);
mark_inode_dirty(inode);
out_unlock_inode:
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
inode_unlock(inode);
#else
mutex_unlock(&inode->i_mutex);
#endif
mnt_drop_write_file(file);
out:
return err;
}
static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 19, 0)
@ -432,8 +559,13 @@ static int exfat_ioctl_fitrim(struct inode *inode, unsigned long arg)
long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
u32 __user *user_attr = (u32 __user *)arg;
switch (cmd) {
case EXFAT_IOCTL_GET_ATTRIBUTES:
return exfat_ioctl_get_attributes(inode, user_attr);
case EXFAT_IOCTL_SET_ATTRIBUTES:
return exfat_ioctl_set_attributes(filp, user_attr);
case FITRIM:
return exfat_ioctl_fitrim(inode, arg);
default: