linux/fs/udf/file.c
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   1/*
   2 * file.c
   3 *
   4 * PURPOSE
   5 *  File handling routines for the OSTA-UDF(tm) filesystem.
   6 *
   7 * COPYRIGHT
   8 *  This file is distributed under the terms of the GNU General Public
   9 *  License (GPL). Copies of the GPL can be obtained from:
  10 *    ftp://prep.ai.mit.edu/pub/gnu/GPL
  11 *  Each contributing author retains all rights to their own work.
  12 *
  13 *  (C) 1998-1999 Dave Boynton
  14 *  (C) 1998-2004 Ben Fennema
  15 *  (C) 1999-2000 Stelias Computing Inc
  16 *
  17 * HISTORY
  18 *
  19 *  10/02/98 dgb  Attempt to integrate into udf.o
  20 *  10/07/98      Switched to using generic_readpage, etc., like isofs
  21 *                And it works!
  22 *  12/06/98 blf  Added udf_file_read. uses generic_file_read for all cases but
  23 *                ICBTAG_FLAG_AD_IN_ICB.
  24 *  04/06/99      64 bit file handling on 32 bit systems taken from ext2 file.c
  25 *  05/12/99      Preliminary file write support
  26 */
  27
  28#include "udfdecl.h"
  29#include <linux/fs.h>
  30#include <asm/uaccess.h>
  31#include <linux/kernel.h>
  32#include <linux/string.h> /* memset */
  33#include <linux/capability.h>
  34#include <linux/errno.h>
  35#include <linux/pagemap.h>
  36#include <linux/buffer_head.h>
  37#include <linux/aio.h>
  38
  39#include "udf_i.h"
  40#include "udf_sb.h"
  41
  42static int udf_adinicb_readpage(struct file *file, struct page *page)
  43{
  44        struct inode *inode = page->mapping->host;
  45        char *kaddr;
  46        struct udf_inode_info *iinfo = UDF_I(inode);
  47
  48        BUG_ON(!PageLocked(page));
  49
  50        kaddr = kmap(page);
  51        memset(kaddr, 0, PAGE_CACHE_SIZE);
  52        memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
  53        flush_dcache_page(page);
  54        SetPageUptodate(page);
  55        kunmap(page);
  56        unlock_page(page);
  57
  58        return 0;
  59}
  60
  61static int udf_adinicb_writepage(struct page *page,
  62                                 struct writeback_control *wbc)
  63{
  64        struct inode *inode = page->mapping->host;
  65        char *kaddr;
  66        struct udf_inode_info *iinfo = UDF_I(inode);
  67
  68        BUG_ON(!PageLocked(page));
  69
  70        kaddr = kmap(page);
  71        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  72        mark_inode_dirty(inode);
  73        SetPageUptodate(page);
  74        kunmap(page);
  75        unlock_page(page);
  76
  77        return 0;
  78}
  79
  80static int udf_adinicb_write_end(struct file *file,
  81                        struct address_space *mapping,
  82                        loff_t pos, unsigned len, unsigned copied,
  83                        struct page *page, void *fsdata)
  84{
  85        struct inode *inode = mapping->host;
  86        unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  87        char *kaddr;
  88        struct udf_inode_info *iinfo = UDF_I(inode);
  89
  90        kaddr = kmap_atomic(page, KM_USER0);
  91        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
  92                kaddr + offset, copied);
  93        kunmap_atomic(kaddr, KM_USER0);
  94
  95        return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  96}
  97
  98const struct address_space_operations udf_adinicb_aops = {
  99        .readpage       = udf_adinicb_readpage,
 100        .writepage      = udf_adinicb_writepage,
 101        .write_begin = simple_write_begin,
 102        .write_end = udf_adinicb_write_end,
 103};
 104
 105static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 106                                  unsigned long nr_segs, loff_t ppos)
 107{
 108        ssize_t retval;
 109        struct file *file = iocb->ki_filp;
 110        struct inode *inode = file->f_path.dentry->d_inode;
 111        int err, pos;
 112        size_t count = iocb->ki_left;
 113        struct udf_inode_info *iinfo = UDF_I(inode);
 114
 115        down_write(&iinfo->i_data_sem);
 116        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 117                if (file->f_flags & O_APPEND)
 118                        pos = inode->i_size;
 119                else
 120                        pos = ppos;
 121
 122                if (inode->i_sb->s_blocksize <
 123                                (udf_file_entry_alloc_offset(inode) +
 124                                                pos + count)) {
 125                        err = udf_expand_file_adinicb(inode);
 126                        if (err) {
 127                                udf_debug("udf_expand_adinicb: err=%d\n", err);
 128                                up_write(&iinfo->i_data_sem);
 129                                return err;
 130                        }
 131                } else {
 132                        if (pos + count > inode->i_size)
 133                                iinfo->i_lenAlloc = pos + count;
 134                        else
 135                                iinfo->i_lenAlloc = inode->i_size;
 136                }
 137        }
 138        up_write(&iinfo->i_data_sem);
 139
 140        retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 141        if (retval > 0)
 142                mark_inode_dirty(inode);
 143
 144        return retval;
 145}
 146
 147long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 148{
 149        struct inode *inode = filp->f_dentry->d_inode;
 150        long old_block, new_block;
 151        int result = -EINVAL;
 152
 153        if (inode_permission(inode, MAY_READ) != 0) {
 154                udf_debug("no permission to access inode %lu\n", inode->i_ino);
 155                result = -EPERM;
 156                goto out;
 157        }
 158
 159        if (!arg) {
 160                udf_debug("invalid argument to udf_ioctl\n");
 161                result = -EINVAL;
 162                goto out;
 163        }
 164
 165        switch (cmd) {
 166        case UDF_GETVOLIDENT:
 167                if (copy_to_user((char __user *)arg,
 168                                 UDF_SB(inode->i_sb)->s_volume_ident, 32))
 169                        result = -EFAULT;
 170                else
 171                        result = 0;
 172                goto out;
 173        case UDF_RELOCATE_BLOCKS:
 174                if (!capable(CAP_SYS_ADMIN)) {
 175                        result = -EACCES;
 176                        goto out;
 177                }
 178                if (get_user(old_block, (long __user *)arg)) {
 179                        result = -EFAULT;
 180                        goto out;
 181                }
 182                result = udf_relocate_blocks(inode->i_sb,
 183                                                old_block, &new_block);
 184                if (result == 0)
 185                        result = put_user(new_block, (long __user *)arg);
 186                goto out;
 187        case UDF_GETEASIZE:
 188                result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 189                goto out;
 190        case UDF_GETEABLOCK:
 191                result = copy_to_user((char __user *)arg,
 192                                      UDF_I(inode)->i_ext.i_data,
 193                                      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 194                goto out;
 195        }
 196
 197out:
 198        return result;
 199}
 200
 201static int udf_release_file(struct inode *inode, struct file *filp)
 202{
 203        if (filp->f_mode & FMODE_WRITE) {
 204                mutex_lock(&inode->i_mutex);
 205                down_write(&UDF_I(inode)->i_data_sem);
 206                udf_discard_prealloc(inode);
 207                udf_truncate_tail_extent(inode);
 208                up_write(&UDF_I(inode)->i_data_sem);
 209                mutex_unlock(&inode->i_mutex);
 210        }
 211        return 0;
 212}
 213
 214const struct file_operations udf_file_operations = {
 215        .read                   = do_sync_read,
 216        .aio_read               = generic_file_aio_read,
 217        .unlocked_ioctl         = udf_ioctl,
 218        .open                   = generic_file_open,
 219        .mmap                   = generic_file_mmap,
 220        .write                  = do_sync_write,
 221        .aio_write              = udf_file_aio_write,
 222        .release                = udf_release_file,
 223        .fsync                  = generic_file_fsync,
 224        .splice_read            = generic_file_splice_read,
 225        .llseek                 = generic_file_llseek,
 226};
 227
 228static int udf_setattr(struct dentry *dentry, struct iattr *attr)
 229{
 230        struct inode *inode = dentry->d_inode;
 231        int error;
 232
 233        error = inode_change_ok(inode, attr);
 234        if (error)
 235                return error;
 236
 237        if ((attr->ia_valid & ATTR_SIZE) &&
 238            attr->ia_size != i_size_read(inode)) {
 239                error = udf_setsize(inode, attr->ia_size);
 240                if (error)
 241                        return error;
 242        }
 243
 244        setattr_copy(inode, attr);
 245        mark_inode_dirty(inode);
 246        return 0;
 247}
 248
 249const struct inode_operations udf_file_inode_operations = {
 250        .setattr                = udf_setattr,
 251};
 252