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                         /* Is it quota file? Do not allow user to mess with it. */
  61                         if (IS_NOQUOTA(inode))
  62                                 return -EPERM;
  63                         if (((flags ^ REISERFS_I(inode)->
  64                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  65                                           REISERFS_APPEND_FL))
  66                             && !capable(CAP_LINUX_IMMUTABLE))
  67                                 return -EPERM;
  68
  69                         if ((flags & REISERFS_NOTAIL_FL) &&
  70                             S_ISREG(inode->i_mode)) {
  71                                 int result;
  72
  73                                 result = reiserfs_unpack(inode, filp);
  74                                 if (result)
  75                                         return result;
  76                         }
  77                         sd_attrs_to_i_attrs(flags, inode);
  78                         REISERFS_I(inode)->i_attrs = flags;
  79                         inode->i_ctime = CURRENT_TIME_SEC;
  80                         mark_inode_dirty(inode);
  81                         return 0;
  82                 }
  83         case REISERFS_IOC_GETVERSION:
  84                 return put_user(inode->i_generation, (int __user *)arg);
  85         case REISERFS_IOC_SETVERSION:
  86                 if (!is_owner_or_cap(inode))
  87                         return -EPERM;
  88                 if (IS_RDONLY(inode))
  89                         return -EROFS;
  90                 if (get_user(inode->i_generation, (int __user *)arg))
  91                         return -EFAULT;
  92                 inode->i_ctime = CURRENT_TIME_SEC;
  93                 mark_inode_dirty(inode);
  94                 return 0;
  95         default:
  96                 return -ENOTTY;
  97         }
  98 }
  99
 100 #ifdef CONFIG_COMPAT
 101 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 102                                 unsigned long arg)
 103 {
 104         struct inode *inode = file->f_path.dentry->d_inode;
 105         int ret;
 106
 107         /* These are just misnamed, they actually get/put from/to user an int */
 108         switch (cmd) {
 109         case REISERFS_IOC32_UNPACK:
 110                 cmd = REISERFS_IOC_UNPACK;
 111                 break;
 112         case REISERFS_IOC32_GETFLAGS:
 113                 cmd = REISERFS_IOC_GETFLAGS;
 114                 break;
 115         case REISERFS_IOC32_SETFLAGS:
 116                 cmd = REISERFS_IOC_SETFLAGS;
 117                 break;
 118         case REISERFS_IOC32_GETVERSION:
 119                 cmd = REISERFS_IOC_GETVERSION;
 120                 break;
 121         case REISERFS_IOC32_SETVERSION:
 122                 cmd = REISERFS_IOC_SETVERSION;
 123                 break;
 124         default:
 125                 return -ENOIOCTLCMD;
 126         }
 127         lock_kernel();
 128         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 129         unlock_kernel();
 130         return ret;
 131 }
 132 #endif
 133
 134 int reiserfs_commit_write(struct file *f, struct page *page,
 135                           unsigned from, unsigned to);
 136 int reiserfs_prepare_write(struct file *f, struct page *page,
 137                            unsigned from, unsigned to);
 138 /*
 139 ** reiserfs_unpack
 140 ** Function try to convert tail from direct item into indirect.
 141 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 142 */
 143 static int reiserfs_unpack(struct inode *inode, struct file *filp)
 144 {
 145         int retval = 0;
 146         int index;
 147         struct page *page;
 148         struct address_space *mapping;
 149         unsigned long write_from;
 150         unsigned long blocksize = inode->i_sb->s_blocksize;
 151
 152         if (inode->i_size == 0) {
 153                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 154                 return 0;
 155         }
 156         /* ioctl already done */
 157         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 158                 return 0;
 159         }
 160
 161         /* we need to make sure nobody is changing the file size beneath
 162          ** us
 163          */
 164         mutex_lock(&inode->i_mutex);
 165         reiserfs_write_lock(inode->i_sb);
 166
 167         write_from = inode->i_size & (blocksize - 1);
 168         /* if we are on a block boundary, we are already unpacked.  */
 169         if (write_from == 0) {
 170                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 171                 goto out;
 172         }
 173
 174         /* we unpack by finding the page with the tail, and calling
 175          ** reiserfs_prepare_write on that page.  This will force a
 176          ** reiserfs_get_block to unpack the tail for us.
 177          */
 178         index = inode->i_size >> PAGE_CACHE_SHIFT;
 179         mapping = inode->i_mapping;
 180         page = grab_cache_page(mapping, index);
 181         retval = -ENOMEM;
 182         if (!page) {
 183                 goto out;
 184         }
 185         retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
 186         if (retval)
 187                 goto out_unlock;
 188
 189         /* conversion can change page contents, must flush */
 190         flush_dcache_page(page);
 191         retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 192         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 193
 194       out_unlock:
 195         unlock_page(page);
 196         page_cache_release(page);
 197
 198       out:
 199         mutex_unlock(&inode->i_mutex);
 200         reiserfs_write_unlock(inode->i_sb);
 201         return retval;
 202 }