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                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_file(filp);
  60                        if (err)
  61                                break;
  62
  63                        if (!inode_owner_or_capable(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);
  99setflags_out:
 100                        mnt_drop_write_file(filp);
 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 (!inode_owner_or_capable(inode)) {
 108                        err = -EPERM;
 109                        break;
 110                }
 111                err = mnt_want_write_file(filp);
 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);
 120setversion_out:
 121                mnt_drop_write_file(filp);
 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
 133long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 134                                unsigned long arg)
 135{
 136        /*
 137         * These are just misnamed, they actually
 138         * get/put from/to user an int
 139         */
 140        switch (cmd) {
 141        case REISERFS_IOC32_UNPACK:
 142                cmd = REISERFS_IOC_UNPACK;
 143                break;
 144        case REISERFS_IOC32_GETFLAGS:
 145                cmd = REISERFS_IOC_GETFLAGS;
 146                break;
 147        case REISERFS_IOC32_SETFLAGS:
 148                cmd = REISERFS_IOC_SETFLAGS;
 149                break;
 150        case REISERFS_IOC32_GETVERSION:
 151                cmd = REISERFS_IOC_GETVERSION;
 152                break;
 153        case REISERFS_IOC32_SETVERSION:
 154                cmd = REISERFS_IOC_SETVERSION;
 155                break;
 156        default:
 157                return -ENOIOCTLCMD;
 158        }
 159
 160        return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 161}
 162#endif
 163
 164int reiserfs_commit_write(struct file *f, struct page *page,
 165                          unsigned from, unsigned to);
 166/*
 167 * reiserfs_unpack
 168 * Function try to convert tail from direct item into indirect.
 169 * It set up nopack attribute in the REISERFS_I(inode)->nopack
 170 */
 171int reiserfs_unpack(struct inode *inode, struct file *filp)
 172{
 173        int retval = 0;
 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        /* we need to make sure nobody is changing the file size beneath us */
 190        reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
 191
 192        reiserfs_write_lock(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        /*
 202         * we unpack by finding the page with the tail, and calling
 203         * __reiserfs_write_begin on that page.  This will force a
 204         * reiserfs_get_block to unpack the tail for us.
 205         */
 206        index = inode->i_size >> PAGE_SHIFT;
 207        mapping = inode->i_mapping;
 208        page = grab_cache_page(mapping, index);
 209        retval = -ENOMEM;
 210        if (!page) {
 211                goto out;
 212        }
 213        retval = __reiserfs_write_begin(page, write_from, 0);
 214        if (retval)
 215                goto out_unlock;
 216
 217        /* conversion can change page contents, must flush */
 218        flush_dcache_page(page);
 219        retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 220        REISERFS_I(inode)->i_flags |= i_nopack_mask;
 221
 222out_unlock:
 223        unlock_page(page);
 224        put_page(page);
 225
 226out:
 227        inode_unlock(inode);
 228        reiserfs_write_unlock(inode->i_sb);
 229        return retval;
 230}
 231