linux/fs/reiserfs/ioctl.c
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   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 <asm/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 to be non-zero)
  19 *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  20 *  3) That's all for a while ...
  21 */
  22long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  23{
  24        struct inode *inode = filp->f_path.dentry->d_inode;
  25        unsigned int flags;
  26        int err = 0;
  27
  28        reiserfs_write_lock(inode->i_sb);
  29
  30        switch (cmd) {
  31        case REISERFS_IOC_UNPACK:
  32                if (S_ISREG(inode->i_mode)) {
  33                        if (arg)
  34                                err = reiserfs_unpack(inode, filp);
  35                } else
  36                        err = -ENOTTY;
  37                break;
  38                /*
  39                 * following two cases are taken from fs/ext2/ioctl.c by Remy
  40                 * Card (card@masi.ibp.fr)
  41                 */
  42        case REISERFS_IOC_GETFLAGS:
  43                if (!reiserfs_attrs(inode->i_sb)) {
  44                        err = -ENOTTY;
  45                        break;
  46                }
  47
  48                flags = REISERFS_I(inode)->i_attrs;
  49                i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
  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                        if (((flags ^ REISERFS_I(inode)->
  78                              i_attrs) & (REISERFS_IMMUTABLE_FL |
  79                                          REISERFS_APPEND_FL))
  80                            && !capable(CAP_LINUX_IMMUTABLE)) {
  81                                err = -EPERM;
  82                                goto setflags_out;
  83                        }
  84                        if ((flags & REISERFS_NOTAIL_FL) &&
  85                            S_ISREG(inode->i_mode)) {
  86                                int result;
  87
  88                                result = reiserfs_unpack(inode, filp);
  89                                if (result) {
  90                                        err = result;
  91                                        goto setflags_out;
  92                                }
  93                        }
  94                        sd_attrs_to_i_attrs(flags, inode);
  95                        REISERFS_I(inode)->i_attrs = flags;
  96                        inode->i_ctime = CURRENT_TIME_SEC;
  97                        mark_inode_dirty(inode);
  98setflags_out:
  99                        mnt_drop_write_file(filp);
 100                        break;
 101                }
 102        case REISERFS_IOC_GETVERSION:
 103                err = put_user(inode->i_generation, (int __user *)arg);
 104                break;
 105        case REISERFS_IOC_SETVERSION:
 106                if (!inode_owner_or_capable(inode)) {
 107                        err = -EPERM;
 108                        break;
 109                }
 110                err = mnt_want_write_file(filp);
 111                if (err)
 112                        break;
 113                if (get_user(inode->i_generation, (int __user *)arg)) {
 114                        err = -EFAULT;
 115                        goto setversion_out;
 116                }
 117                inode->i_ctime = CURRENT_TIME_SEC;
 118                mark_inode_dirty(inode);
 119setversion_out:
 120                mnt_drop_write_file(filp);
 121                break;
 122        default:
 123                err = -ENOTTY;
 124        }
 125
 126        reiserfs_write_unlock(inode->i_sb);
 127
 128        return err;
 129}
 130
 131#ifdef CONFIG_COMPAT
 132long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 133                                unsigned long arg)
 134{
 135        /* These are just misnamed, they actually get/put from/to user an int */
 136        switch (cmd) {
 137        case REISERFS_IOC32_UNPACK:
 138                cmd = REISERFS_IOC_UNPACK;
 139                break;
 140        case REISERFS_IOC32_GETFLAGS:
 141                cmd = REISERFS_IOC_GETFLAGS;
 142                break;
 143        case REISERFS_IOC32_SETFLAGS:
 144                cmd = REISERFS_IOC_SETFLAGS;
 145                break;
 146        case REISERFS_IOC32_GETVERSION:
 147                cmd = REISERFS_IOC_GETVERSION;
 148                break;
 149        case REISERFS_IOC32_SETVERSION:
 150                cmd = REISERFS_IOC_SETVERSION;
 151                break;
 152        default:
 153                return -ENOIOCTLCMD;
 154        }
 155
 156        return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 157}
 158#endif
 159
 160int reiserfs_commit_write(struct file *f, struct page *page,
 161                          unsigned from, unsigned to);
 162/*
 163** reiserfs_unpack
 164** Function try to convert tail from direct item into indirect.
 165** It set up nopack attribute in the REISERFS_I(inode)->nopack
 166*/
 167int reiserfs_unpack(struct inode *inode, struct file *filp)
 168{
 169        int retval = 0;
 170        int depth;
 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        depth = reiserfs_write_lock_once(inode->i_sb);
 187
 188        /* we need to make sure nobody is changing the file size beneath us */
 189        reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);
 190
 191        write_from = inode->i_size & (blocksize - 1);
 192        /* if we are on a block boundary, we are already unpacked.  */
 193        if (write_from == 0) {
 194                REISERFS_I(inode)->i_flags |= i_nopack_mask;
 195                goto out;
 196        }
 197
 198        /* we unpack by finding the page with the tail, and calling
 199         ** __reiserfs_write_begin on that page.  This will force a
 200         ** reiserfs_get_block to unpack the tail for us.
 201         */
 202        index = inode->i_size >> PAGE_CACHE_SHIFT;
 203        mapping = inode->i_mapping;
 204        page = grab_cache_page(mapping, index);
 205        retval = -ENOMEM;
 206        if (!page) {
 207                goto out;
 208        }
 209        retval = __reiserfs_write_begin(page, write_from, 0);
 210        if (retval)
 211                goto out_unlock;
 212
 213        /* conversion can change page contents, must flush */
 214        flush_dcache_page(page);
 215        retval = reiserfs_commit_write(NULL, page, write_from, write_from);
 216        REISERFS_I(inode)->i_flags |= i_nopack_mask;
 217
 218      out_unlock:
 219        unlock_page(page);
 220        page_cache_release(page);
 221
 222      out:
 223        mutex_unlock(&inode->i_mutex);
 224        reiserfs_write_unlock_once(inode->i_sb, depth);
 225        return retval;
 226}
 227
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