release/src-rt-6.x.4708/linux/linux-2.6.36/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 <linux/reiserfs_fs.h>
   9 #include <linux/time.h>
  10 #include <asm/uaccess.h>
  11 #include <linux/pagemap.h>
  12 #include <linux/smp_lock.h>
  13 #include <linux/compat.h>
  14
  15 /*
  16  * reiserfs_ioctl - handler for ioctl for inode
  17  * supported commands:
  18  *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  19  *                           and prevent packing file (argument arg has to be non-zero)
  20  *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  21  *  3) That's all for a while ...
  22  */
  23 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  24 {
  25         struct inode *inode = filp->f_path.dentry->d_inode;
  26         unsigned int flags;
  27         int err = 0;
  28
  29         reiserfs_write_lock(inode->i_sb);
  30
  31         switch (cmd) {
  32         case REISERFS_IOC_UNPACK:
  33                 if (S_ISREG(inode->i_mode)) {
  34                         if (arg)
  35                                 err = reiserfs_unpack(inode, filp);
  36                 } else
  37                         err = -ENOTTY;
  38                 break;
  39                 /*
  40                  * following two cases are taken from fs/ext2/ioctl.c by Remy
  41                  * Card (card@masi.ibp.fr)
  42                  */
  43         case REISERFS_IOC_GETFLAGS:
  44                 if (!reiserfs_attrs(inode->i_sb)) {
  45                         err = -ENOTTY;
  46                         break;
  47                 }
  48
  49                 flags = REISERFS_I(inode)->i_attrs;
  50                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  51                 err = put_user(flags, (int __user *)arg);
  52                 break;
  53         case REISERFS_IOC_SETFLAGS:{
  54                         if (!reiserfs_attrs(inode->i_sb)) {
  55                                 err = -ENOTTY;
  56                                 break;
  57                         }
  58
  59                         err = mnt_want_write(filp->f_path.mnt);
  60                         if (err)
  61                                 break;
  62
  63                         if (!is_owner_or_cap(inode)) {
  64                                 err = -EPERM;
  65                                 goto setflags_out;
  66                         }
  67                         if (get_user(flags, (int __user *)arg)) {
  68                                 err = -EFAULT;
  69                                 goto setflags_out;
  70                         }
  71                         /*
  72                          * Is it quota file? Do not allow user to mess with it
  73                          */
  74                         if (IS_NOQUOTA(inode)) {
  75                                 err = -EPERM;
  76                                 goto setflags_out;
  77                         }
  78                         if (((flags ^ REISERFS_I(inode)->
  79                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  80                                           REISERFS_APPEND_FL))
  81                             && !capable(CAP_LINUX_IMMUTABLE)) {
  82                                 err = -EPERM;
  83                                 goto setflags_out;
  84                         }
  85                         if ((flags & REISERFS_NOTAIL_FL) &&
  86                             S_ISREG(inode->i_mode)) {
  87                                 int result;
  88
  89                                 result = reiserfs_unpack(inode, filp);
  90                                 if (result) {
  91                                         err = result;
  92                                         goto setflags_out;
  93                                 }
  94                         }
  95                         sd_attrs_to_i_attrs(flags, inode);
  96                         REISERFS_I(inode)->i_attrs = flags;
  97                         inode->i_ctime = CURRENT_TIME_SEC;
  98                         mark_inode_dirty(inode);
  99 setflags_out:
 100                         mnt_drop_write(filp->f_path.mnt);
 101                         break;
 102                 }
 103         case REISERFS_IOC_GETVERSION:
 104                 err = put_user(inode->i_generation, (int __user *)arg);
 105                 break;
 106         case REISERFS_IOC_SETVERSION:
 107                 if (!is_owner_or_cap(inode)) {
 108                         err = -EPERM;
 109                         break;
 110                 }
 111                 err = mnt_want_write(filp->f_path.mnt);
 112                 if (err)
 113                         break;
 114                 if (get_user(inode->i_generation, (int __user *)arg)) {
 115                         err = -EFAULT;
 116                         goto setversion_out;
 117                 }
 118                 inode->i_ctime = CURRENT_TIME_SEC;
 119                 mark_inode_dirty(inode);
 120 setversion_out:
 121                 mnt_drop_write(filp->f_path.mnt);
 122                 break;
 123         default:
 124                 err = -ENOTTY;
 125         }
 126
 127         reiserfs_write_unlock(inode->i_sb);
 128
 129         return err;
 130 }
 131
 132 #ifdef CONFIG_COMPAT
 133 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 134                                 unsigned long arg)
 135 {
 136         /* These are just misnamed, they actually get/put from/to user an int */
 137         switch (cmd) {
 138         case REISERFS_IOC32_UNPACK:
 139                 cmd = REISERFS_IOC_UNPACK;
 140                 break;
 141         case REISERFS_IOC32_GETFLAGS:
 142                 cmd = REISERFS_IOC_GETFLAGS;
 143                 break;
 144         case REISERFS_IOC32_SETFLAGS:
 145                 cmd = REISERFS_IOC_SETFLAGS;
 146                 break;
 147         case REISERFS_IOC32_GETVERSION:
 148                 cmd = REISERFS_IOC_GETVERSION;
 149                 break;
 150         case REISERFS_IOC32_SETVERSION:
 151                 cmd = REISERFS_IOC_SETVERSION;
 152                 break;
 153         default:
 154                 return -ENOIOCTLCMD;
 155         }
 156
 157         return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 158 }
 159 #endif
 160
 161 int reiserfs_commit_write(struct file *f, struct page *page,
 162                           unsigned from, unsigned to);
 163 int reiserfs_prepare_write(struct file *f, struct page *page,
 164                            unsigned from, unsigned to);
 165 /*
 166 ** reiserfs_unpack
 167 ** Function try to convert tail from direct item into indirect.
 168 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 169 */
 170 int reiserfs_unpack(struct inode *inode, struct file *filp)
 171 {
 172         int retval = 0;
 173         int depth;
 174         int index;
 175         struct page *page;
 176         struct address_space *mapping;
 177         unsigned long write_from;
 178         unsigned long blocksize = inode->i_sb->s_blocksize;
 179
 180         if (inode->i_size == 0) {
 181                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 182                 return 0;
 183         }
 184         /* ioctl already done */
 185         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 186                 return 0;
 187         }
 188
 189         depth = reiserfs_write_lock_once(inode->i_sb);
 190
 191         /* we need to make sure nobody is changing the file size beneath us */
 192         reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
 193
 194         write_from = inode->i_size & (blocksize - 1);
 195         /* if we are on a block boundary, we are already unpacked.  */
 196         if (write_from == 0) {
 197                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 198                 goto out;
 199         }
 200
 201         /* we unpack by finding the page with the tail, and calling
 202          ** reiserfs_prepare_write on that page.  This will force a
 203          ** reiserfs_get_block to unpack the tail for us.
 204          */
 205         index = inode->i_size >> PAGE_CACHE_SHIFT;
 206         mapping = inode->i_mapping;
 207         page = grab_cache_page(mapping, index);
 208         retval = -ENOMEM;
 209         if (!page) {
 210                 goto out;
 211         }
 212         retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
 213         if (retval)
 214                 goto out_unlock;
 215
 216         /* conversion can change page contents, must flush */
 217         flush_dcache_page(page);
 218         retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 219         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 220
 221       out_unlock:
 222         unlock_page(page);
 223         page_cache_release(page);
 224
 225       out:
 226         mutex_unlock(&inode->i_mutex);
 227         reiserfs_write_unlock_once(inode->i_sb, depth);
 228         return retval;
 229 }