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/mount.h>
  12 #include <linux/time.h>
  13 #include <linux/sched.h>
  14 #include <asm/current.h>
  15 #include <asm/uaccess.h>
  16
  17 #include "jfs_incore.h"
  18 #include "jfs_dinode.h"
  19 #include "jfs_inode.h"
  20
  21
  22 static struct {
  23         long jfs_flag;
  24         long ext2_flag;
  25 } jfs_map[] = {
  26         {JFS_NOATIME_FL,        FS_NOATIME_FL},
  27         {JFS_DIRSYNC_FL,        FS_DIRSYNC_FL},
  28         {JFS_SYNC_FL,           FS_SYNC_FL},
  29         {JFS_SECRM_FL,          FS_SECRM_FL},
  30         {JFS_UNRM_FL,           FS_UNRM_FL},
  31         {JFS_APPEND_FL,         FS_APPEND_FL},
  32         {JFS_IMMUTABLE_FL,      FS_IMMUTABLE_FL},
  33         {0, 0},
  34 };
  35
  36 static long jfs_map_ext2(unsigned long flags, int from)
  37 {
  38         int index=0;
  39         long mapped=0;
  40
  41         while (jfs_map[index].jfs_flag) {
  42                 if (from) {
  43                         if (jfs_map[index].ext2_flag & flags)
  44                                 mapped |= jfs_map[index].jfs_flag;
  45                 } else {
  46                         if (jfs_map[index].jfs_flag & flags)
  47                                 mapped |= jfs_map[index].ext2_flag;
  48                 }
  49                 index++;
  50         }
  51         return mapped;
  52 }
  53
  54
  55 long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  56 {
  57         struct inode *inode = filp->f_dentry->d_inode;
  58         struct jfs_inode_info *jfs_inode = JFS_IP(inode);
  59         unsigned int flags;
  60
  61         switch (cmd) {
  62         case JFS_IOC_GETFLAGS:
  63                 jfs_get_inode_flags(jfs_inode);
  64                 flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
  65                 flags = jfs_map_ext2(flags, 0);
  66                 return put_user(flags, (int __user *) arg);
  67         case JFS_IOC_SETFLAGS: {
  68                 unsigned int oldflags;
  69                 int err;
  70
  71                 err = mnt_want_write(filp->f_path.mnt);
  72                 if (err)
  73                         return err;
  74
  75                 if (!is_owner_or_cap(inode)) {
  76                         err = -EACCES;
  77                         goto setflags_out;
  78                 }
  79                 if (get_user(flags, (int __user *) arg)) {
  80                         err = -EFAULT;
  81                         goto setflags_out;
  82                 }
  83
  84                 flags = jfs_map_ext2(flags, 1);
  85                 if (!S_ISDIR(inode->i_mode))
  86                         flags &= ~JFS_DIRSYNC_FL;
  87
  88                 /* Is it quota file? Do not allow user to mess with it */
  89                 if (IS_NOQUOTA(inode)) {
  90                         err = -EPERM;
  91                         goto setflags_out;
  92                 }
  93
  94                 /* Lock against other parallel changes of flags */
  95                 mutex_lock(&inode->i_mutex);
  96
  97                 jfs_get_inode_flags(jfs_inode);
  98                 oldflags = jfs_inode->mode2;
  99
 100                 /*
 101                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 102                  * the relevant capability.
 103                  */
 104                 if ((oldflags & JFS_IMMUTABLE_FL) ||
 105                         ((flags ^ oldflags) &
 106                         (JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
 107                         if (!capable(CAP_LINUX_IMMUTABLE)) {
 108                                 mutex_unlock(&inode->i_mutex);
 109                                 err = -EPERM;
 110                                 goto setflags_out;
 111                         }
 112                 }
 113
 114                 flags = flags & JFS_FL_USER_MODIFIABLE;
 115                 flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
 116                 jfs_inode->mode2 = flags;
 117
 118                 jfs_set_inode_flags(inode);
 119                 mutex_unlock(&inode->i_mutex);
 120                 inode->i_ctime = CURRENT_TIME_SEC;
 121                 mark_inode_dirty(inode);
 122 setflags_out:
 123                 mnt_drop_write(filp->f_path.mnt);
 124                 return err;
 125         }
 126         default:
 127                 return -ENOTTY;
 128         }
 129 }
 130
 131 #ifdef CONFIG_COMPAT
 132 long jfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 133 {
 134         /* While these ioctl numbers defined with 'long' and have different
 135          * numbers than the 64bit ABI,
 136          * the actual implementation only deals with ints and is compatible.
 137          */
 138         switch (cmd) {
 139         case JFS_IOC_GETFLAGS32:
 140                 cmd = JFS_IOC_GETFLAGS;
 141                 break;
 142         case JFS_IOC_SETFLAGS32:
 143                 cmd = JFS_IOC_SETFLAGS;
 144                 break;
 145         }
 146         return jfs_ioctl(filp, cmd, arg);
 147 }
 148 #endif