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 (!is_owner_or_cap(inode))
  55                                 return -EPERM;
  56
  57                         if (get_user(flags, (int __user *)arg))
  58                                 return -EFAULT;
  59
  60                         if (((flags ^ REISERFS_I(inode)->
  61                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  62                                           REISERFS_APPEND_FL))
  63                             && !capable(CAP_LINUX_IMMUTABLE))
  64                                 return -EPERM;
  65
  66                         if ((flags & REISERFS_NOTAIL_FL) &&
  67                             S_ISREG(inode->i_mode)) {
  68                                 int result;
  69
  70                                 result = reiserfs_unpack(inode, filp);
  71                                 if (result)
  72                                         return result;
  73                         }
  74                         sd_attrs_to_i_attrs(flags, inode);
  75                         REISERFS_I(inode)->i_attrs = flags;
  76                         inode->i_ctime = CURRENT_TIME_SEC;
  77                         mark_inode_dirty(inode);
  78                         return 0;
  79                 }
  80         case REISERFS_IOC_GETVERSION:
  81                 return put_user(inode->i_generation, (int __user *)arg);
  82         case REISERFS_IOC_SETVERSION:
  83                 if (!is_owner_or_cap(inode))
  84                         return -EPERM;
  85                 if (IS_RDONLY(inode))
  86                         return -EROFS;
  87                 if (get_user(inode->i_generation, (int __user *)arg))
  88                         return -EFAULT;
  89                 inode->i_ctime = CURRENT_TIME_SEC;
  90                 mark_inode_dirty(inode);
  91                 return 0;
  92         default:
  93                 return -ENOTTY;
  94         }
  95 }
  96
  97 #ifdef CONFIG_COMPAT
  98 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
  99                                 unsigned long arg)
 100 {
 101         struct inode *inode = file->f_path.dentry->d_inode;
 102         int ret;
 103
 104         /* These are just misnamed, they actually get/put from/to user an int */
 105         switch (cmd) {
 106         case REISERFS_IOC32_UNPACK:
 107                 cmd = REISERFS_IOC_UNPACK;
 108                 break;
 109         case REISERFS_IOC32_GETFLAGS:
 110                 cmd = REISERFS_IOC_GETFLAGS;
 111                 break;
 112         case REISERFS_IOC32_SETFLAGS:
 113                 cmd = REISERFS_IOC_SETFLAGS;
 114                 break;
 115         case REISERFS_IOC32_GETVERSION:
 116                 cmd = REISERFS_IOC_GETVERSION;
 117                 break;
 118         case REISERFS_IOC32_SETVERSION:
 119                 cmd = REISERFS_IOC_SETVERSION;
 120                 break;
 121         default:
 122                 return -ENOIOCTLCMD;
 123         }
 124         lock_kernel();
 125         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 126         unlock_kernel();
 127         return ret;
 128 }
 129 #endif
 130
 131 /*
 132 ** reiserfs_unpack
 133 ** Function try to convert tail from direct item into indirect.
 134 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 135 */
 136 static int reiserfs_unpack(struct inode *inode, struct file *filp)
 137 {
 138         int retval = 0;
 139         int index;
 140         struct page *page;
 141         struct address_space *mapping;
 142         unsigned long write_from;
 143         unsigned long blocksize = inode->i_sb->s_blocksize;
 144
 145         if (inode->i_size == 0) {
 146                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 147                 return 0;
 148         }
 149         /* ioctl already done */
 150         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 151                 return 0;
 152         }
 153
 154         /* we need to make sure nobody is changing the file size beneath
 155          ** us
 156          */
 157         mutex_lock(&inode->i_mutex);
 158         reiserfs_write_lock(inode->i_sb);
 159
 160         write_from = inode->i_size & (blocksize - 1);
 161         /* if we are on a block boundary, we are already unpacked.  */
 162         if (write_from == 0) {
 163                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 164                 goto out;
 165         }
 166
 167         /* we unpack by finding the page with the tail, and calling
 168          ** reiserfs_prepare_write on that page.  This will force a
 169          ** reiserfs_get_block to unpack the tail for us.
 170          */
 171         index = inode->i_size >> PAGE_CACHE_SHIFT;
 172         mapping = inode->i_mapping;
 173         page = grab_cache_page(mapping, index);
 174         retval = -ENOMEM;
 175         if (!page) {
 176                 goto out;
 177         }
 178         retval =
 179             mapping->a_ops->prepare_write(NULL, page, write_from, write_from);
 180         if (retval)
 181                 goto out_unlock;
 182
 183         /* conversion can change page contents, must flush */
 184         flush_dcache_page(page);
 185         retval =
 186             mapping->a_ops->commit_write(NULL, page, write_from, write_from);
 187         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 188
 189       out_unlock:
 190         unlock_page(page);
 191         page_cache_release(page);
 192
 193       out:
 194         mutex_unlock(&inode->i_mutex);
 195         reiserfs_write_unlock(inode->i_sb);
 196         return retval;
 197 }