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 <linux/uaccess.h>
  11#include <linux/pagemap.h>
  12#include <linux/compat.h>
  13#include <linux/fileattr.h>
  14
  15int reiserfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
  16{
  17        struct inode *inode = d_inode(dentry);
  18
  19        if (!reiserfs_attrs(inode->i_sb))
  20                return -ENOTTY;
  21
  22        fileattr_fill_flags(fa, REISERFS_I(inode)->i_attrs);
  23
  24        return 0;
  25}
  26
  27int reiserfs_fileattr_set(struct user_namespace *mnt_userns,
  28                          struct dentry *dentry, struct fileattr *fa)
  29{
  30        struct inode *inode = d_inode(dentry);
  31        unsigned int flags = fa->flags;
  32        int err;
  33
  34        reiserfs_write_lock(inode->i_sb);
  35
  36        err = -ENOTTY;
  37        if (!reiserfs_attrs(inode->i_sb))
  38                goto unlock;
  39
  40        err = -EOPNOTSUPP;
  41        if (fileattr_has_fsx(fa))
  42                goto unlock;
  43
  44        /*
  45         * Is it quota file? Do not allow user to mess with it
  46         */
  47        err = -EPERM;
  48        if (IS_NOQUOTA(inode))
  49                goto unlock;
  50
  51        if ((flags & REISERFS_NOTAIL_FL) && S_ISREG(inode->i_mode)) {
  52                err = reiserfs_unpack(inode);
  53                if (err)
  54                        goto unlock;
  55        }
  56        sd_attrs_to_i_attrs(flags, inode);
  57        REISERFS_I(inode)->i_attrs = flags;
  58        inode->i_ctime = current_time(inode);
  59        mark_inode_dirty(inode);
  60        err = 0;
  61unlock:
  62        reiserfs_write_unlock(inode->i_sb);
  63
  64        return err;
  65}
  66
  67/*
  68 * reiserfs_ioctl - handler for ioctl for inode
  69 * supported commands:
  70 *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
  71 *                           and prevent packing file (argument arg has t
  72 *                            be non-zero)
  73 *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
  74 *  3) That's all for a while ...
  75 */
  76long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  77{
  78        struct inode *inode = file_inode(filp);
  79        int err = 0;
  80
  81        reiserfs_write_lock(inode->i_sb);
  82
  83        switch (cmd) {
  84        case REISERFS_IOC_UNPACK:
  85                if (S_ISREG(inode->i_mode)) {
  86                        if (arg)
  87                                err = reiserfs_unpack(inode);
  88                } else
  89                        err = -ENOTTY;
  90                break;
  91                /*
  92                 * following two cases are taken from fs/ext2/ioctl.c by Remy
  93                 * Card (card@masi.ibp.fr)
  94                 */
  95        case REISERFS_IOC_GETVERSION:
  96                err = put_user(inode->i_generation, (int __user *)arg);
  97                break;
  98        case REISERFS_IOC_SETVERSION:
  99                if (!inode_owner_or_capable(&init_user_ns, inode)) {
 100                        err = -EPERM;
 101                        break;
 102                }
 103                err = mnt_want_write_file(filp);
 104                if (err)
 105                        break;
 106                if (get_user(inode->i_generation, (int __user *)arg)) {
 107                        err = -EFAULT;
 108                        goto setversion_out;
 109                }
 110                inode->i_ctime = current_time(inode);
 111                mark_inode_dirty(inode);
 112setversion_out:
 113                mnt_drop_write_file(filp);
 114                break;
 115        default:
 116                err = -ENOTTY;
 117        }
 118
 119        reiserfs_write_unlock(inode->i_sb);
 120
 121        return err;
 122}
 123
 124#ifdef CONFIG_COMPAT
 125long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
 126                                unsigned long arg)
 127{
 128        /*
 129         * These are just misnamed, they actually
 130         * get/put from/to user an int
 131         */
 132        switch (cmd) {
 133        case REISERFS_IOC32_UNPACK:
 134                cmd = REISERFS_IOC_UNPACK;
 135                break;
 136        case REISERFS_IOC32_GETVERSION:
 137                cmd = REISERFS_IOC_GETVERSION;
 138                break;
 139        case REISERFS_IOC32_SETVERSION:
 140                cmd = REISERFS_IOC_SETVERSION;
 141                break;
 142        default:
 143                return -ENOIOCTLCMD;
 144        }
 145
 146        return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 147}
 148#endif
 149
 150int reiserfs_commit_write(struct file *f, struct page *page,
 151                          unsigned from, unsigned to);
 152/*
 153 * reiserfs_unpack
 154 * Function try to convert tail from direct item into indirect.
 155 * It set up nopack attribute in the REISERFS_I(inode)->nopack
 156 */
 157int reiserfs_unpack(struct inode *inode)
 158{
 159        int retval = 0;
 160        int index;
 161        struct page *page;
 162        struct address_space *mapping;
 163        unsigned long write_from;
 164        unsigned long blocksize = inode->i_sb->s_blocksize;
 165
 166        if (inode->i_size == 0) {
 167                REISERFS_I(inode)->i_flags |= i_nopack_mask;
 168                return 0;
 169        }
 170        /* ioctl already done */
 171        if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
 172                return 0;
 173        }
 174
 175        /* we need to make sure nobody is changing the file size beneath us */
 176        {
 177                int depth = reiserfs_write_unlock_nested(inode->i_sb);
 178
 179                inode_lock(inode);
 180                reiserfs_write_lock_nested(inode->i_sb, depth);
 181        }
 182
 183        reiserfs_write_lock(inode->i_sb);
 184
 185        write_from = inode->i_size & (blocksize - 1);
 186        /* if we are on a block boundary, we are already unpacked.  */
 187        if (write_from == 0) {
 188                REISERFS_I(inode)->i_flags |= i_nopack_mask;
 189                goto out;
 190        }
 191
 192        /*
 193         * we unpack by finding the page with the tail, and calling
 194         * __reiserfs_write_begin on that page.  This will force a
 195         * reiserfs_get_block to unpack the tail for us.
 196         */
 197        index = inode->i_size >> PAGE_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_write_begin(page, write_from, 0);
 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
 213out_unlock:
 214        unlock_page(page);
 215        put_page(page);
 216
 217out:
 218        inode_unlock(inode);
 219        reiserfs_write_unlock(inode->i_sb);
 220        return retval;
 221}
 222