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/mount.h>
   8 #include "reiserfs.h"
   9 #include <linux/time.h>
  10 #include <asm/uaccess.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/compat.h>
  13
  14 /*
  15  * reiserfs_ioctl - handler for ioctl for inode
  16  * supported commands:
  17  *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  18  *                           and prevent packing file (argument arg has to be non-zero)
  19  *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  20  *  3) That's all for a while ...
  21  */
  22 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  23 {
  24         struct inode *inode = file_inode(filp);
  25         unsigned int flags;
  26         int err = 0;
  27
  28         reiserfs_write_lock(inode->i_sb);
  29
  30         switch (cmd) {
  31         case REISERFS_IOC_UNPACK:
  32                 if (S_ISREG(inode->i_mode)) {
  33                         if (arg)
  34                                 err = reiserfs_unpack(inode, filp);
  35                 } else
  36                         err = -ENOTTY;
  37                 break;
  38                 /*
  39                  * following two cases are taken from fs/ext2/ioctl.c by Remy
  40                  * Card (card@masi.ibp.fr)
  41                  */
  42         case REISERFS_IOC_GETFLAGS:
  43                 if (!reiserfs_attrs(inode->i_sb)) {
  44                         err = -ENOTTY;
  45                         break;
  46                 }
  47
  48                 flags = REISERFS_I(inode)->i_attrs;
  49                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  50                 err = put_user(flags, (int __user *)arg);
  51                 break;
  52         case REISERFS_IOC_SETFLAGS:{
  53                         if (!reiserfs_attrs(inode->i_sb)) {
  54                                 err = -ENOTTY;
  55                                 break;
  56                         }
  57
  58                         err = mnt_want_write_file(filp);
  59                         if (err)
  60                                 break;
  61
  62                         if (!inode_owner_or_capable(inode)) {
  63                                 err = -EPERM;
  64                                 goto setflags_out;
  65                         }
  66                         if (get_user(flags, (int __user *)arg)) {
  67                                 err = -EFAULT;
  68                                 goto setflags_out;
  69                         }
  70                         /*
  71                          * Is it quota file? Do not allow user to mess with it
  72                          */
  73                         if (IS_NOQUOTA(inode)) {
  74                                 err = -EPERM;
  75                                 goto setflags_out;
  76                         }
  77                         if (((flags ^ REISERFS_I(inode)->
  78                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  79                                           REISERFS_APPEND_FL))
  80                             && !capable(CAP_LINUX_IMMUTABLE)) {
  81                                 err = -EPERM;
  82                                 goto setflags_out;
  83                         }
  84                         if ((flags & REISERFS_NOTAIL_FL) &&
  85                             S_ISREG(inode->i_mode)) {
  86                                 int result;
  87
  88                                 result = reiserfs_unpack(inode, filp);
  89                                 if (result) {
  90                                         err = result;
  91                                         goto setflags_out;
  92                                 }
  93                         }
  94                         sd_attrs_to_i_attrs(flags, inode);
  95                         REISERFS_I(inode)->i_attrs = flags;
  96                         inode->i_ctime = CURRENT_TIME_SEC;
  97                         mark_inode_dirty(inode);
  98 setflags_out:
  99                         mnt_drop_write_file(filp);
 100                         break;
 101                 }
 102         case REISERFS_IOC_GETVERSION:
 103                 err = put_user(inode->i_generation, (int __user *)arg);
 104                 break;
 105         case REISERFS_IOC_SETVERSION:
 106                 if (!inode_owner_or_capable(inode)) {
 107                         err = -EPERM;
 108                         break;
 109                 }
 110                 err = mnt_want_write_file(filp);
 111                 if (err)
 112                         break;
 113                 if (get_user(inode->i_generation, (int __user *)arg)) {
 114                         err = -EFAULT;
 115                         goto setversion_out;
 116                 }
 117                 inode->i_ctime = CURRENT_TIME_SEC;
 118                 mark_inode_dirty(inode);
 119 setversion_out:
 120                 mnt_drop_write_file(filp);
 121                 break;
 122         default:
 123                 err = -ENOTTY;
 124         }
 125
 126         reiserfs_write_unlock(inode->i_sb);
 127
 128         return err;
 129 }
 130
 131 #ifdef CONFIG_COMPAT
 132 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 133                                 unsigned long arg)
 134 {
 135         /* These are just misnamed, they actually get/put from/to user an int */
 136         switch (cmd) {
 137         case REISERFS_IOC32_UNPACK:
 138                 cmd = REISERFS_IOC_UNPACK;
 139                 break;
 140         case REISERFS_IOC32_GETFLAGS:
 141                 cmd = REISERFS_IOC_GETFLAGS;
 142                 break;
 143         case REISERFS_IOC32_SETFLAGS:
 144                 cmd = REISERFS_IOC_SETFLAGS;
 145                 break;
 146         case REISERFS_IOC32_GETVERSION:
 147                 cmd = REISERFS_IOC_GETVERSION;
 148                 break;
 149         case REISERFS_IOC32_SETVERSION:
 150                 cmd = REISERFS_IOC_SETVERSION;
 151                 break;
 152         default:
 153                 return -ENOIOCTLCMD;
 154         }
 155
 156         return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 157 }
 158 #endif
 159
 160 int reiserfs_commit_write(struct file *f, struct page *page,
 161                           unsigned from, unsigned to);
 162 /*
 163 ** reiserfs_unpack
 164 ** Function try to convert tail from direct item into indirect.
 165 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 166 */
 167 int reiserfs_unpack(struct inode *inode, struct file *filp)
 168 {
 169         int retval = 0;
 170         int index;
 171         struct page *page;
 172         struct address_space *mapping;
 173         unsigned long write_from;
 174         unsigned long blocksize = inode->i_sb->s_blocksize;
 175
 176         if (inode->i_size == 0) {
 177                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 178                 return 0;
 179         }
 180         /* ioctl already done */
 181         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 182                 return 0;
 183         }
 184
 185         /* we need to make sure nobody is changing the file size beneath us */
 186         reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
 187
 188         reiserfs_write_lock(inode->i_sb);
 189
 190         write_from = inode->i_size & (blocksize - 1);
 191         /* if we are on a block boundary, we are already unpacked.  */
 192         if (write_from == 0) {
 193                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 194                 goto out;
 195         }
 196
 197         /* we unpack by finding the page with the tail, and calling
 198          ** __reiserfs_write_begin on that page.  This will force a
 199          ** reiserfs_get_block to unpack the tail for us.
 200          */
 201         index = inode->i_size >> PAGE_CACHE_SHIFT;
 202         mapping = inode->i_mapping;
 203         page = grab_cache_page(mapping, index);
 204         retval = -ENOMEM;
 205         if (!page) {
 206                 goto out;
 207         }
 208         retval = __reiserfs_write_begin(page, write_from, 0);
 209         if (retval)
 210                 goto out_unlock;
 211
 212         /* conversion can change page contents, must flush */
 213         flush_dcache_page(page);
 214         retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 215         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 216
 217       out_unlock:
 218         unlock_page(page);
 219         page_cache_release(page);
 220
 221       out:
 222         mutex_unlock(&inode->i_mutex);
 223         reiserfs_write_unlock(inode->i_sb);
 224         return retval;
 225 }