fs/jfs/ioctl.c

   1 /*
   2  * linux/fs/jfs/ioctl.c
   3  *
   4  * Copyright (C) 2006 Herbert Poetzl
   5  * adapted from Remy Card's ext2/ioctl.c
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/ctype.h>
  10 #include <linux/capability.h>
  11 #include <linux/time.h>
  12 #include <linux/sched.h>
  13 #include <asm/current.h>
  14 #include <asm/uaccess.h>
  15
  16 #include "jfs_incore.h"
  17 #include "jfs_dinode.h"
  18 #include "jfs_inode.h"
  19
  20
  21 static struct {
  22         long jfs_flag;
  23         long ext2_flag;
  24 } jfs_map[] = {
  25         {JFS_NOATIME_FL,        FS_NOATIME_FL},
  26         {JFS_DIRSYNC_FL,        FS_DIRSYNC_FL},
  27         {JFS_SYNC_FL,           FS_SYNC_FL},
  28         {JFS_SECRM_FL,          FS_SECRM_FL},
  29         {JFS_UNRM_FL,           FS_UNRM_FL},
  30         {JFS_APPEND_FL,         FS_APPEND_FL},
  31         {JFS_IMMUTABLE_FL,      FS_IMMUTABLE_FL},
  32         {0, 0},
  33 };
  34
  35 static long jfs_map_ext2(unsigned long flags, int from)
  36 {
  37         int index=0;
  38         long mapped=0;
  39
  40         while (jfs_map[index].jfs_flag) {
  41                 if (from) {
  42                         if (jfs_map[index].ext2_flag & flags)
  43                                 mapped |= jfs_map[index].jfs_flag;
  44                 } else {
  45                         if (jfs_map[index].jfs_flag & flags)
  46                                 mapped |= jfs_map[index].ext2_flag;
  47                 }
  48                 index++;
  49         }
  50         return mapped;
  51 }
  52
  53
  54 long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  55 {
  56         struct inode *inode = filp->f_dentry->d_inode;
  57         struct jfs_inode_info *jfs_inode = JFS_IP(inode);
  58         unsigned int flags;
  59
  60         switch (cmd) {
  61         case JFS_IOC_GETFLAGS:
  62                 jfs_get_inode_flags(jfs_inode);
  63                 flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
  64                 flags = jfs_map_ext2(flags, 0);
  65                 return put_user(flags, (int __user *) arg);
  66         case JFS_IOC_SETFLAGS: {
  67                 unsigned int oldflags;
  68
  69                 if (IS_RDONLY(inode))
  70                         return -EROFS;
  71
  72                 if (!is_owner_or_cap(inode))
  73                         return -EACCES;
  74
  75                 if (get_user(flags, (int __user *) arg))
  76                         return -EFAULT;
  77
  78                 flags = jfs_map_ext2(flags, 1);
  79                 if (!S_ISDIR(inode->i_mode))
  80                         flags &= ~JFS_DIRSYNC_FL;
  81
  82                 /* Is it quota file? Do not allow user to mess with it */
  83                 if (IS_NOQUOTA(inode))
  84                         return -EPERM;
  85
  86                 /* Lock against other parallel changes of flags */
  87                 mutex_lock(&inode->i_mutex);
  88
  89                 jfs_get_inode_flags(jfs_inode);
  90                 oldflags = jfs_inode->mode2;
  91
  92                 /*
  93                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  94                  * the relevant capability.
  95                  */
  96                 if ((oldflags & JFS_IMMUTABLE_FL) ||
  97                         ((flags ^ oldflags) &
  98                         (JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
  99                         if (!capable(CAP_LINUX_IMMUTABLE)) {
 100                                 mutex_unlock(&inode->i_mutex);
 101                                 return -EPERM;
 102                         }
 103                 }
 104
 105                 flags = flags & JFS_FL_USER_MODIFIABLE;
 106                 flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
 107                 jfs_inode->mode2 = flags;
 108
 109                 jfs_set_inode_flags(inode);
 110                 mutex_unlock(&inode->i_mutex);
 111                 inode->i_ctime = CURRENT_TIME_SEC;
 112                 mark_inode_dirty(inode);
 113                 return 0;
 114         }
 115         default:
 116                 return -ENOTTY;
 117         }
 118 }
 119