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 static int reiserfs_unpack(struct inode *inode, struct file *filp);
  16
  17 /*
  18 ** reiserfs_ioctl - handler for ioctl for inode
  19 ** supported commands:
  20 **  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  21 **                           and prevent packing file (argument arg has to be non-zero)
  22 **  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  23 **  3) That's all for a while ...
  24 */
  25 int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
  26                    unsigned long arg)
  27 {
  28         unsigned int flags;
  29         int err = 0;
  30
  31         switch (cmd) {
  32         case REISERFS_IOC_UNPACK:
  33                 if (S_ISREG(inode->i_mode)) {
  34                         if (arg)
  35                                 return reiserfs_unpack(inode, filp);
  36                         else
  37                                 return 0;
  38                 } else
  39                         return -ENOTTY;
  40                 /* following two cases are taken from fs/ext2/ioctl.c by Remy
  41                    Card (card@masi.ibp.fr) */
  42         case REISERFS_IOC_GETFLAGS:
  43                 if (!reiserfs_attrs(inode->i_sb))
  44                         return -ENOTTY;
  45
  46                 flags = REISERFS_I(inode)->i_attrs;
  47                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  48                 return put_user(flags, (int __user *)arg);
  49         case REISERFS_IOC_SETFLAGS:{
  50                         if (!reiserfs_attrs(inode->i_sb))
  51                                 return -ENOTTY;
  52
  53                         err = mnt_want_write(filp->f_path.mnt);
  54                         if (err)
  55                                 return err;
  56
  57                         if (!is_owner_or_cap(inode)) {
  58                                 err = -EPERM;
  59                                 goto setflags_out;
  60                         }
  61                         if (get_user(flags, (int __user *)arg)) {
  62                                 err = -EFAULT;
  63                                 goto setflags_out;
  64                         }
  65                         /*
  66                          * Is it quota file? Do not allow user to mess with it
  67                          */
  68                         if (IS_NOQUOTA(inode)) {
  69                                 err = -EPERM;
  70                                 goto setflags_out;
  71                         }
  72                         if (((flags ^ REISERFS_I(inode)->
  73                               i_attrs) & (REISERFS_IMMUTABLE_FL |
  74                                           REISERFS_APPEND_FL))
  75                             && !capable(CAP_LINUX_IMMUTABLE)) {
  76                                 err = -EPERM;
  77                                 goto setflags_out;
  78                         }
  79                         if ((flags & REISERFS_NOTAIL_FL) &&
  80                             S_ISREG(inode->i_mode)) {
  81                                 int result;
  82
  83                                 result = reiserfs_unpack(inode, filp);
  84                                 if (result) {
  85                                         err = result;
  86                                         goto setflags_out;
  87                                 }
  88                         }
  89                         sd_attrs_to_i_attrs(flags, inode);
  90                         REISERFS_I(inode)->i_attrs = flags;
  91                         inode->i_ctime = CURRENT_TIME_SEC;
  92                         mark_inode_dirty(inode);
  93 setflags_out:
  94                         mnt_drop_write(filp->f_path.mnt);
  95                         return err;
  96                 }
  97         case REISERFS_IOC_GETVERSION:
  98                 return put_user(inode->i_generation, (int __user *)arg);
  99         case REISERFS_IOC_SETVERSION:
 100                 if (!is_owner_or_cap(inode))
 101                         return -EPERM;
 102                 err = mnt_want_write(filp->f_path.mnt);
 103                 if (err)
 104                         return err;
 105                 if (get_user(inode->i_generation, (int __user *)arg)) {
 106                         err = -EFAULT;
 107                         goto setversion_out;
 108                 }
 109                 inode->i_ctime = CURRENT_TIME_SEC;
 110                 mark_inode_dirty(inode);
 111 setversion_out:
 112                 mnt_drop_write(filp->f_path.mnt);
 113                 return err;
 114         default:
 115                 return -ENOTTY;
 116         }
 117 }
 118
 119 #ifdef CONFIG_COMPAT
 120 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 121                                 unsigned long arg)
 122 {
 123         struct inode *inode = file->f_path.dentry->d_inode;
 124         int ret;
 125
 126         /* These are just misnamed, they actually get/put from/to user an int */
 127         switch (cmd) {
 128         case REISERFS_IOC32_UNPACK:
 129                 cmd = REISERFS_IOC_UNPACK;
 130                 break;
 131         case REISERFS_IOC32_GETFLAGS:
 132                 cmd = REISERFS_IOC_GETFLAGS;
 133                 break;
 134         case REISERFS_IOC32_SETFLAGS:
 135                 cmd = REISERFS_IOC_SETFLAGS;
 136                 break;
 137         case REISERFS_IOC32_GETVERSION:
 138                 cmd = REISERFS_IOC_GETVERSION;
 139                 break;
 140         case REISERFS_IOC32_SETVERSION:
 141                 cmd = REISERFS_IOC_SETVERSION;
 142                 break;
 143         default:
 144                 return -ENOIOCTLCMD;
 145         }
 146         lock_kernel();
 147         ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 148         unlock_kernel();
 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 static 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 }