fs/ext2/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/fs/ext2/ioctl.c
   4  *
   5  * Copyright (C) 1993, 1994, 1995
   6  * Remy Card (card@masi.ibp.fr)
   7  * Laboratoire MASI - Institut Blaise Pascal
   8  * Universite Pierre et Marie Curie (Paris VI)
   9  */
  10
  11 #include "ext2.h"
  12 #include <linux/capability.h>
  13 #include <linux/time.h>
  14 #include <linux/sched.h>
  15 #include <linux/compat.h>
  16 #include <linux/mount.h>
  17 #include <asm/current.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/fileattr.h>
  20
  21 int ext2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
  22 {
  23         struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
  24
  25         fileattr_fill_flags(fa, ei->i_flags & EXT2_FL_USER_VISIBLE);
  26
  27         return 0;
  28 }
  29
  30 int ext2_fileattr_set(struct user_namespace *mnt_userns,
  31                       struct dentry *dentry, struct fileattr *fa)
  32 {
  33         struct inode *inode = d_inode(dentry);
  34         struct ext2_inode_info *ei = EXT2_I(inode);
  35
  36         if (fileattr_has_fsx(fa))
  37                 return -EOPNOTSUPP;
  38
  39         /* Is it quota file? Do not allow user to mess with it */
  40         if (IS_NOQUOTA(inode))
  41                 return -EPERM;
  42
  43         ei->i_flags = (ei->i_flags & ~EXT2_FL_USER_MODIFIABLE) |
  44                 (fa->flags & EXT2_FL_USER_MODIFIABLE);
  45
  46         ext2_set_inode_flags(inode);
  47         inode->i_ctime = current_time(inode);
  48         mark_inode_dirty(inode);
  49
  50         return 0;
  51 }
  52
  53
  54 long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  55 {
  56         struct inode *inode = file_inode(filp);
  57         struct ext2_inode_info *ei = EXT2_I(inode);
  58         unsigned short rsv_window_size;
  59         int ret;
  60
  61         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  62
  63         switch (cmd) {
  64         case EXT2_IOC_GETVERSION:
  65                 return put_user(inode->i_generation, (int __user *) arg);
  66         case EXT2_IOC_SETVERSION: {
  67                 __u32 generation;
  68
  69                 if (!inode_owner_or_capable(&init_user_ns, inode))
  70                         return -EPERM;
  71                 ret = mnt_want_write_file(filp);
  72                 if (ret)
  73                         return ret;
  74                 if (get_user(generation, (int __user *) arg)) {
  75                         ret = -EFAULT;
  76                         goto setversion_out;
  77                 }
  78
  79                 inode_lock(inode);
  80                 inode->i_ctime = current_time(inode);
  81                 inode->i_generation = generation;
  82                 inode_unlock(inode);
  83
  84                 mark_inode_dirty(inode);
  85 setversion_out:
  86                 mnt_drop_write_file(filp);
  87                 return ret;
  88         }
  89         case EXT2_IOC_GETRSVSZ:
  90                 if (test_opt(inode->i_sb, RESERVATION)
  91                         && S_ISREG(inode->i_mode)
  92                         && ei->i_block_alloc_info) {
  93                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
  94                         return put_user(rsv_window_size, (int __user *)arg);
  95                 }
  96                 return -ENOTTY;
  97         case EXT2_IOC_SETRSVSZ: {
  98
  99                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 100                         return -ENOTTY;
 101
 102                 if (!inode_owner_or_capable(&init_user_ns, inode))
 103                         return -EACCES;
 104
 105                 if (get_user(rsv_window_size, (int __user *)arg))
 106                         return -EFAULT;
 107
 108                 ret = mnt_want_write_file(filp);
 109                 if (ret)
 110                         return ret;
 111
 112                 if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 113                         rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 114
 115                 /*
 116                  * need to allocate reservation structure for this inode
 117                  * before set the window size
 118                  */
 119                 /*
 120                  * XXX What lock should protect the rsv_goal_size?
 121                  * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 122                  */
 123                 mutex_lock(&ei->truncate_mutex);
 124                 if (!ei->i_block_alloc_info)
 125                         ext2_init_block_alloc_info(inode);
 126
 127                 if (ei->i_block_alloc_info){
 128                         struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 129                         rsv->rsv_goal_size = rsv_window_size;
 130                 } else {
 131                         ret = -ENOMEM;
 132                 }
 133
 134                 mutex_unlock(&ei->truncate_mutex);
 135                 mnt_drop_write_file(filp);
 136                 return ret;
 137         }
 138         default:
 139                 return -ENOTTY;
 140         }
 141 }
 142
 143 #ifdef CONFIG_COMPAT
 144 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 145 {
 146         /* These are just misnamed, they actually get/put from/to user an int */
 147         switch (cmd) {
 148         case EXT2_IOC32_GETVERSION:
 149                 cmd = EXT2_IOC_GETVERSION;
 150                 break;
 151         case EXT2_IOC32_SETVERSION:
 152                 cmd = EXT2_IOC_SETVERSION;
 153                 break;
 154         default:
 155                 return -ENOIOCTLCMD;
 156         }
 157         return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 158 }
 159 #endif