fs/reiserfs/ioctl.c

   1 /*
   2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3  */
   4
   5 #include <linux/capability.h>
   6 #include <linux/fs.h>
   7 #include <linux/reiserfs_fs.h>
   8 #include <linux/time.h>
   9 #include <asm/uaccess.h>
  10 #include <linux/pagemap.h>
  11 #include <linux/smp_lock.h>
  12 #include <linux/compat.h>
  13
  14 static int reiserfs_unpack(struct inode *inode, struct file *filp);
  15
  16 /*
  17 ** reiserfs_ioctl - handler for ioctl for inode
  18 ** supported commands:
  19 **  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  20 **                           and prevent packing file (argument arg has to be non-zero)
  21 **  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  22 **  3) That's all for a while ...
  23 */
  24 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
  25                    unsigned long arg)
  26 {
  27         unsigned int flags;
  28
  29         switch (cmd) {
  30         case REISERFS_IOC_UNPACK:
  31                 if (S_ISREG(inode->i_mode)) {
  32                         if (arg)
  33                                 return reiserfs_unpack(inode, filp);
  34                         else
  35                                 return 0;
  36                 } else
  37                         return -ENOTTY;
  38                 /* following two cases are taken from fs/ext2/ioctl.c by Remy
  39                    Card (card@masi.ibp.fr) */
  40         case REISERFS_IOC_GETFLAGS:
  41                 if (!reiserfs_attrs(inode->i_sb))
  42                         return -ENOTTY;
  43
  44                 flags = REISERFS_I(inode)->i_attrs;
  45                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  46                 return put_user(flags, (int __user *)arg);
  47         case REISERFS_IOC_SETFLAGS:{
  48                         if (!reiserfs_attrs(inode->i_sb))
  49                                 return -ENOTTY;
  50
  51                         if (IS_RDONLY(inode))
  52                                 return -EROFS;
  53
  54                         if ((current->fsuid != inode->i_uid)
  55                             && !capable(CAP_FOWNER))
  56                                 return -EPERM;
  57
  58                         if (get_user(flags, (int __user *)arg))
  59                                 return -EFAULT;
  60
  61                         if (((flags ^ REISERFS_I(inode)->
  62                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  63                                           REISERFS_APPEND_FL))
  64                             && !capable(CAP_LINUX_IMMUTABLE))
  65                                 return -EPERM;
  66
  67                         if ((flags & REISERFS_NOTAIL_FL) &&
  68                             S_ISREG(inode->i_mode)) {
  69                                 int result;
  70
  71                                 result = reiserfs_unpack(inode, filp);
  72                                 if (result)
  73                                         return result;
  74                         }
  75                         sd_attrs_to_i_attrs(flags, inode);
  76                         REISERFS_I(inode)->i_attrs = flags;
  77                         inode->i_ctime = CURRENT_TIME_SEC;
  78                         mark_inode_dirty(inode);
  79                         return 0;
  80                 }
  81         case REISERFS_IOC_GETVERSION:
  82                 return put_user(inode->i_generation, (int __user *)arg);
  83         case REISERFS_IOC_SETVERSION:
  84                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  85                         return -EPERM;
  86                 if (IS_RDONLY(inode))
  87                         return -EROFS;
  88                 if (get_user(inode->i_generation, (int __user *)arg))
  89                         return -EFAULT;
  90                 inode->i_ctime = CURRENT_TIME_SEC;
  91                 mark_inode_dirty(inode);
  92                 return 0;
  93         default:
  94                 return -ENOTTY;
  95         }
  96 }
  97
  98 #ifdef CONFIG_COMPAT
  99 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 100                                 unsigned long arg)
 101 {
 102         struct inode *inode = file->f_path.dentry->d_inode;
 103         int ret;
 104
 105         /* These are just misnamed, they actually get/put from/to user an int */
 106         switch (cmd) {
 107         case REISERFS_IOC32_UNPACK:
 108                 cmd = REISERFS_IOC_UNPACK;
 109                 break;
 110         case REISERFS_IOC32_GETFLAGS:
 111                 cmd = REISERFS_IOC_GETFLAGS;
 112                 break;
 113         case REISERFS_IOC32_SETFLAGS:
 114                 cmd = REISERFS_IOC_SETFLAGS;
 115                 break;
 116         case REISERFS_IOC32_GETVERSION:
 117                 cmd = REISERFS_IOC_GETVERSION;
 118                 break;
 119         case REISERFS_IOC32_SETVERSION:
 120                 cmd = REISERFS_IOC_SETVERSION;
 121                 break;
 122         default:
 123                 return -ENOIOCTLCMD;
 124         }
 125         lock_kernel();
 126         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 127         unlock_kernel();
 128         return ret;
 129 }
 130 #endif
 131
 132 /*
 133 ** reiserfs_unpack
 134 ** Function try to convert tail from direct item into indirect.
 135 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 136 */
 137 static int reiserfs_unpack(struct inode *inode, struct file *filp)
 138 {
 139         int retval = 0;
 140         int index;
 141         struct page *page;
 142         struct address_space *mapping;
 143         unsigned long write_from;
 144         unsigned long blocksize = inode->i_sb->s_blocksize;
 145
 146         if (inode->i_size == 0) {
 147                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 148                 return 0;
 149         }
 150         /* ioctl already done */
 151         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 152                 return 0;
 153         }
 154
 155         /* we need to make sure nobody is changing the file size beneath
 156          ** us
 157          */
 158         mutex_lock(&inode->i_mutex);
 159         reiserfs_write_lock(inode->i_sb);
 160
 161         write_from = inode->i_size & (blocksize - 1);
 162         /* if we are on a block boundary, we are already unpacked.  */
 163         if (write_from == 0) {
 164                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 165                 goto out;
 166         }
 167
 168         /* we unpack by finding the page with the tail, and calling
 169          ** reiserfs_prepare_write on that page.  This will force a
 170          ** reiserfs_get_block to unpack the tail for us.
 171          */
 172         index = inode->i_size >> PAGE_CACHE_SHIFT;
 173         mapping = inode->i_mapping;
 174         page = grab_cache_page(mapping, index);
 175         retval = -ENOMEM;
 176         if (!page) {
 177                 goto out;
 178         }
 179         retval =
 180             mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
 181         if (retval)
 182                 goto out_unlock;
 183
 184         /* conversion can change page contents, must flush */
 185         flush_dcache_page(page);
 186         retval =
 187             mapping->a_ops->commit_write(NULL, page, write_from, write_from);
 188         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 189
 190       out_unlock:
 191         unlock_page(page);
 192         page_cache_release(page);
 193
 194       out:
 195         mutex_unlock(&inode->i_mutex);
 196         reiserfs_write_unlock(inode->i_sb);
 197         return retval;
 198 }