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 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
  24                    unsigned long arg)
  25 {
  26         unsigned int flags;
  27         int err = 0;
  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                         err = mnt_want_write(filp->f_path.mnt);
  52                         if (err)
  53                                 return err;
  54
  55                         if (!is_owner_or_cap(inode)) {
  56                                 err = -EPERM;
  57                                 goto setflags_out;
  58                         }
  59                         if (get_user(flags, (int __user *)arg)) {
  60                                 err = -EFAULT;
  61                                 goto setflags_out;
  62                         }
  63                         /*
  64                          * Is it quota file? Do not allow user to mess with it
  65                          */
  66                         if (IS_NOQUOTA(inode)) {
  67                                 err = -EPERM;
  68                                 goto setflags_out;
  69                         }
  70                         if (((flags ^ REISERFS_I(inode)->
  71                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  72                                           REISERFS_APPEND_FL))
  73                             && !capable(CAP_LINUX_IMMUTABLE)) {
  74                                 err = -EPERM;
  75                                 goto setflags_out;
  76                         }
  77                         if ((flags & REISERFS_NOTAIL_FL) &&
  78                             S_ISREG(inode->i_mode)) {
  79                                 int result;
  80
  81                                 result = reiserfs_unpack(inode, filp);
  82                                 if (result) {
  83                                         err = result;
  84                                         goto setflags_out;
  85                                 }
  86                         }
  87                         sd_attrs_to_i_attrs(flags, inode);
  88                         REISERFS_I(inode)->i_attrs = flags;
  89                         inode->i_ctime = CURRENT_TIME_SEC;
  90                         mark_inode_dirty(inode);
  91 setflags_out:
  92                         mnt_drop_write(filp->f_path.mnt);
  93                         return err;
  94                 }
  95         case REISERFS_IOC_GETVERSION:
  96                 return put_user(inode->i_generation, (int __user *)arg);
  97         case REISERFS_IOC_SETVERSION:
  98                 if (!is_owner_or_cap(inode))
  99                         return -EPERM;
 100                 err = mnt_want_write(filp->f_path.mnt);
 101                 if (err)
 102                         return err;
 103                 if (get_user(inode->i_generation, (int __user *)arg)) {
 104                         err = -EFAULT;
 105                         goto setversion_out;
 106                 }
 107                 inode->i_ctime = CURRENT_TIME_SEC;
 108                 mark_inode_dirty(inode);
 109 setversion_out:
 110                 mnt_drop_write(filp->f_path.mnt);
 111                 return err;
 112         default:
 113                 return -ENOTTY;
 114         }
 115 }
 116
 117 #ifdef CONFIG_COMPAT
 118 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 119                                 unsigned long arg)
 120 {
 121         struct inode *inode = file->f_path.dentry->d_inode;
 122         int ret;
 123
 124         /* These are just misnamed, they actually get/put from/to user an int */
 125         switch (cmd) {
 126         case REISERFS_IOC32_UNPACK:
 127                 cmd = REISERFS_IOC_UNPACK;
 128                 break;
 129         case REISERFS_IOC32_GETFLAGS:
 130                 cmd = REISERFS_IOC_GETFLAGS;
 131                 break;
 132         case REISERFS_IOC32_SETFLAGS:
 133                 cmd = REISERFS_IOC_SETFLAGS;
 134                 break;
 135         case REISERFS_IOC32_GETVERSION:
 136                 cmd = REISERFS_IOC_GETVERSION;
 137                 break;
 138         case REISERFS_IOC32_SETVERSION:
 139                 cmd = REISERFS_IOC_SETVERSION;
 140                 break;
 141         default:
 142                 return -ENOIOCTLCMD;
 143         }
 144
 145         reiserfs_write_lock(inode->i_sb);
 146         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 147         reiserfs_write_unlock(inode->i_sb);
 148
 149         return ret;
 150 }
 151 #endif
 152
 153 int reiserfs_commit_write(struct file *f, struct page *page,
 154                           unsigned from, unsigned to);
 155 int reiserfs_prepare_write(struct file *f, struct page *page,
 156                            unsigned from, unsigned to);
 157 /*
 158 ** reiserfs_unpack
 159 ** Function try to convert tail from direct item into indirect.
 160 ** It set up nopack attribute in the REISERFS_I(inode)->nopack
 161 */
 162 int reiserfs_unpack(struct inode *inode, struct file *filp)
 163 {
 164         int retval = 0;
 165         int index;
 166         struct page *page;
 167         struct address_space *mapping;
 168         unsigned long write_from;
 169         unsigned long blocksize = inode->i_sb->s_blocksize;
 170
 171         if (inode->i_size == 0) {
 172                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 173                 return 0;
 174         }
 175         /* ioctl already done */
 176         if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 177                 return 0;
 178         }
 179
 180         /* we need to make sure nobody is changing the file size beneath
 181          ** us
 182          */
 183         mutex_lock(&inode->i_mutex);
 184         reiserfs_write_lock(inode->i_sb);
 185
 186         write_from = inode->i_size & (blocksize - 1);
 187         /* if we are on a block boundary, we are already unpacked.  */
 188         if (write_from == 0) {
 189                 REISERFS_I(inode)->i_flags |= i_nopack_mask;
 190                 goto out;
 191         }
 192
 193         /* we unpack by finding the page with the tail, and calling
 194          ** reiserfs_prepare_write on that page.  This will force a
 195          ** reiserfs_get_block to unpack the tail for us.
 196          */
 197         index = inode->i_size >> PAGE_CACHE_SHIFT;
 198         mapping = inode->i_mapping;
 199         page = grab_cache_page(mapping, index);
 200         retval = -ENOMEM;
 201         if (!page) {
 202                 goto out;
 203         }
 204         retval = reiserfs_prepare_write(NULL, page, write_from, write_from);
 205         if (retval)
 206                 goto out_unlock;
 207
 208         /* conversion can change page contents, must flush */
 209         flush_dcache_page(page);
 210         retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 211         REISERFS_I(inode)->i_flags |= i_nopack_mask;
 212
 213       out_unlock:
 214         unlock_page(page);
 215         page_cache_release(page);
 216
 217       out:
 218         mutex_unlock(&inode->i_mutex);
 219         reiserfs_write_unlock(inode->i_sb);
 220         return retval;
 221 }