LXR linux/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 <linux/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 t
  19 *                            be non-zero)
  20 *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  21 *  3) That's all for a while ...
  22 */
  23long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  24{
  25        struct inode *inode = file_inode(filp);
  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                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                        err = vfs_ioc_setflags_prepare(inode,
  78                                                     REISERFS_I(inode)->i_attrs,
  79                                                     flags);
  80                        if (err)
  81                                goto setflags_out;
  82                        if ((flags & REISERFS_NOTAIL_FL) &&
  83                            S_ISREG(inode->i_mode)) {
  84                                int result;
  85
  86                                result = reiserfs_unpack(inode, filp);
  87                                if (result) {
  88                                        err = result;
  89                                        goto setflags_out;
  90                                }
  91                        }
  92                        sd_attrs_to_i_attrs(flags, inode);
  93                        REISERFS_I(inode)->i_attrs = flags;
  94                        inode->i_ctime = current_time(inode);
  95                        mark_inode_dirty(inode);
  96setflags_out:
  97                        mnt_drop_write_file(filp);
  98                        break;
  99                }
 100        case REISERFS_IOC_GETVERSION:
 101                err = put_user(inode->i_generation, (int __user *)arg);
 102                break;
 103        case REISERFS_IOC_SETVERSION:
 104                if (!inode_owner_or_capable(inode)) {
 105                        err = -EPERM;
 106                        break;
 107                }
 108                err = mnt_want_write_file(filp);
 109                if (err)
 110                        break;
 111                if (get_user(inode->i_generation, (int __user *)arg)) {
 112                        err = -EFAULT;
 113                        goto setversion_out;
 114                }
 115                inode->i_ctime = current_time(inode);
 116                mark_inode_dirty(inode);
 117setversion_out:
 118                mnt_drop_write_file(filp);
 119                break;
 120        default:
 121                err = -ENOTTY;
 122        }
 123
 124        reiserfs_write_unlock(inode->i_sb);
 125
 126        return err;
 127}
 128
 129#ifdef CONFIG_COMPAT
 130long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 131                                unsigned long arg)
 132{
 133        /*
 134         * These are just misnamed, they actually
 135         * get/put from/to user an int
 136         */
 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
 161int reiserfs_commit_write(struct file *f, struct page *page,
 162                          unsigned from, unsigned to);
 163/*
 164 * reiserfs_unpack
 165 * Function try to convert tail from direct item into indirect.
 166 * It set up nopack attribute in the REISERFS_I(inode)->nopack
 167 */
 168int reiserfs_unpack(struct inode *inode, struct file *filp)
 169{
 170        int retval = 0;
 171        int index;
 172        struct page *page;
 173        struct address_space *mapping;
 174        unsigned long write_from;
 175        unsigned long blocksize = inode->i_sb->s_blocksize;
 176
 177        if (inode->i_size == 0) {
 178                REISERFS_I(inode)->i_flags |= i_nopack_mask;
 179                return 0;
 180        }
 181        /* ioctl already done */
 182        if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 183                return 0;
 184        }
 185
 186        /* we need to make sure nobody is changing the file size beneath us */
 187        {
 188                int depth = reiserfs_write_unlock_nested(inode->i_sb);
 189
 190                inode_lock(inode);
 191                reiserfs_write_lock_nested(inode->i_sb, depth);
 192        }
 193
 194        reiserfs_write_lock(inode->i_sb);
 195
 196        write_from = inode->i_size & (blocksize - 1);
 197        /* if we are on a block boundary, we are already unpacked.  */
 198        if (write_from == 0) {
 199                REISERFS_I(inode)->i_flags |= i_nopack_mask;
 200                goto out;
 201        }
 202
 203        /*
 204         * we unpack by finding the page with the tail, and calling
 205         * __reiserfs_write_begin on that page.  This will force a
 206         * reiserfs_get_block to unpack the tail for us.
 207         */
 208        index = inode->i_size >> PAGE_SHIFT;
 209        mapping = inode->i_mapping;
 210        page = grab_cache_page(mapping, index);
 211        retval = -ENOMEM;
 212        if (!page) {
 213                goto out;
 214        }
 215        retval = __reiserfs_write_begin(page, write_from, 0);
 216        if (retval)
 217                goto out_unlock;
 218
 219        /* conversion can change page contents, must flush */
 220        flush_dcache_page(page);
 221        retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 222        REISERFS_I(inode)->i_flags |= i_nopack_mask;
 223
 224out_unlock:
 225        unlock_page(page);
 226        put_page(page);
 227
 228out:
 229        inode_unlock(inode);
 230        reiserfs_write_unlock(inode->i_sb);
 231        return retval;
 232}
 233