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/smp_lock.h>
  36#include <linux/pagemap.h>
  37#include <linux/buffer_head.h>
  38#include <linux/aio.h>
  39
  40#include "udf_i.h"
  41#include "udf_sb.h"
  42
  43static int udf_adinicb_readpage(struct file *file, struct page *page)
  44{
  45        struct inode *inode = page->mapping->host;
  46        char *kaddr;
  47        struct udf_inode_info *iinfo = UDF_I(inode);
  48
  49        BUG_ON(!PageLocked(page));
  50
  51        kaddr = kmap(page);
  52        memset(kaddr, 0, PAGE_CACHE_SIZE);
  53        memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
  54        flush_dcache_page(page);
  55        SetPageUptodate(page);
  56        kunmap(page);
  57        unlock_page(page);
  58
  59        return 0;
  60}
  61
  62static int udf_adinicb_writepage(struct page *page,
  63                                 struct writeback_control *wbc)
  64{
  65        struct inode *inode = page->mapping->host;
  66        char *kaddr;
  67        struct udf_inode_info *iinfo = UDF_I(inode);
  68
  69        BUG_ON(!PageLocked(page));
  70
  71        kaddr = kmap(page);
  72        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  73        mark_inode_dirty(inode);
  74        SetPageUptodate(page);
  75        kunmap(page);
  76        unlock_page(page);
  77
  78        return 0;
  79}
  80
  81static int udf_adinicb_write_end(struct file *file,
  82                        struct address_space *mapping,
  83                        loff_t pos, unsigned len, unsigned copied,
  84                        struct page *page, void *fsdata)
  85{
  86        struct inode *inode = mapping->host;
  87        unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  88        char *kaddr;
  89        struct udf_inode_info *iinfo = UDF_I(inode);
  90
  91        kaddr = kmap_atomic(page, KM_USER0);
  92        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
  93                kaddr + offset, copied);
  94        kunmap_atomic(kaddr, KM_USER0);
  95
  96        return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  97}
  98
  99const struct address_space_operations udf_adinicb_aops = {
 100        .readpage       = udf_adinicb_readpage,
 101        .writepage      = udf_adinicb_writepage,
 102        .sync_page      = block_sync_page,
 103        .write_begin = simple_write_begin,
 104        .write_end = udf_adinicb_write_end,
 105};
 106
 107static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 108                                  unsigned long nr_segs, loff_t ppos)
 109{
 110        ssize_t retval;
 111        struct file *file = iocb->ki_filp;
 112        struct inode *inode = file->f_path.dentry->d_inode;
 113        int err, pos;
 114        size_t count = iocb->ki_left;
 115        struct udf_inode_info *iinfo = UDF_I(inode);
 116
 117        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 118                if (file->f_flags & O_APPEND)
 119                        pos = inode->i_size;
 120                else
 121                        pos = ppos;
 122
 123                if (inode->i_sb->s_blocksize <
 124                                (udf_file_entry_alloc_offset(inode) +
 125                                                pos + count)) {
 126                        udf_expand_file_adinicb(inode, pos + count, &err);
 127                        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 128                                udf_debug("udf_expand_adinicb: err=%d\n", err);
 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
 139        retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 140        if (retval > 0)
 141                mark_inode_dirty(inode);
 142
 143        return retval;
 144}
 145
 146int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 147              unsigned long arg)
 148{
 149        long old_block, new_block;
 150        int result = -EINVAL;
 151
 152        if (file_permission(filp, MAY_READ) != 0) {
 153                udf_debug("no permission to access inode %lu\n",
 154                          inode->i_ino);
 155                return -EPERM;
 156        }
 157
 158        if (!arg) {
 159                udf_debug("invalid argument to udf_ioctl\n");
 160                return -EINVAL;
 161        }
 162
 163        switch (cmd) {
 164        case UDF_GETVOLIDENT:
 165                if (copy_to_user((char __user *)arg,
 166                                 UDF_SB(inode->i_sb)->s_volume_ident, 32))
 167                        return -EFAULT;
 168                else
 169                        return 0;
 170        case UDF_RELOCATE_BLOCKS:
 171                if (!capable(CAP_SYS_ADMIN))
 172                        return -EACCES;
 173                if (get_user(old_block, (long __user *)arg))
 174                        return -EFAULT;
 175                result = udf_relocate_blocks(inode->i_sb,
 176                                                old_block, &new_block);
 177                if (result == 0)
 178                        result = put_user(new_block, (long __user *)arg);
 179                return result;
 180        case UDF_GETEASIZE:
 181                result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 182                break;
 183        case UDF_GETEABLOCK:
 184                result = copy_to_user((char __user *)arg,
 185                                      UDF_I(inode)->i_ext.i_data,
 186                                      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 187                break;
 188        }
 189
 190        return result;
 191}
 192
 193static int udf_release_file(struct inode *inode, struct file *filp)
 194{
 195        if (filp->f_mode & FMODE_WRITE) {
 196                mutex_lock(&inode->i_mutex);
 197                lock_kernel();
 198                udf_discard_prealloc(inode);
 199                unlock_kernel();
 200                mutex_unlock(&inode->i_mutex);
 201        }
 202        return 0;
 203}
 204
 205const struct file_operations udf_file_operations = {
 206        .read                   = do_sync_read,
 207        .aio_read               = generic_file_aio_read,
 208        .ioctl                  = udf_ioctl,
 209        .open                   = generic_file_open,
 210        .mmap                   = generic_file_mmap,
 211        .write                  = do_sync_write,
 212        .aio_write              = udf_file_aio_write,
 213        .release                = udf_release_file,
 214        .fsync                  = simple_fsync,
 215        .splice_read            = generic_file_splice_read,
 216        .llseek                 = generic_file_llseek,
 217};
 218
 219const struct inode_operations udf_file_inode_operations = {
 220        .truncate = udf_truncate,
 221};
 222