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 void __udf_adinicb_readpage(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        kaddr = kmap(page);
  49        memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
  50        memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size);
  51        flush_dcache_page(page);
  52        SetPageUptodate(page);
  53        kunmap(page);
  54}
  55
  56static int udf_adinicb_readpage(struct file *file, struct page *page)
  57{
  58        BUG_ON(!PageLocked(page));
  59        __udf_adinicb_readpage(page);
  60        unlock_page(page);
  61
  62        return 0;
  63}
  64
  65static int udf_adinicb_writepage(struct page *page,
  66                                 struct writeback_control *wbc)
  67{
  68        struct inode *inode = page->mapping->host;
  69        char *kaddr;
  70        struct udf_inode_info *iinfo = UDF_I(inode);
  71
  72        BUG_ON(!PageLocked(page));
  73
  74        kaddr = kmap(page);
  75        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  76        mark_inode_dirty(inode);
  77        SetPageUptodate(page);
  78        kunmap(page);
  79        unlock_page(page);
  80
  81        return 0;
  82}
  83
  84static int udf_adinicb_write_begin(struct file *file,
  85                        struct address_space *mapping, loff_t pos,
  86                        unsigned len, unsigned flags, struct page **pagep,
  87                        void **fsdata)
  88{
  89        struct page *page;
  90
  91        if (WARN_ON_ONCE(pos >= PAGE_CACHE_SIZE))
  92                return -EIO;
  93        page = grab_cache_page_write_begin(mapping, 0, flags);
  94        if (!page)
  95                return -ENOMEM;
  96        *pagep = page;
  97
  98        if (!PageUptodate(page) && len != PAGE_CACHE_SIZE)
  99                __udf_adinicb_readpage(page);
 100        return 0;
 101}
 102
 103static int udf_adinicb_write_end(struct file *file,
 104                        struct address_space *mapping,
 105                        loff_t pos, unsigned len, unsigned copied,
 106                        struct page *page, void *fsdata)
 107{
 108        struct inode *inode = mapping->host;
 109        unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
 110        char *kaddr;
 111        struct udf_inode_info *iinfo = UDF_I(inode);
 112
 113        kaddr = kmap_atomic(page);
 114        memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
 115                kaddr + offset, copied);
 116        kunmap_atomic(kaddr);
 117
 118        return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
 119}
 120
 121const struct address_space_operations udf_adinicb_aops = {
 122        .readpage       = udf_adinicb_readpage,
 123        .writepage      = udf_adinicb_writepage,
 124        .write_begin    = udf_adinicb_write_begin,
 125        .write_end      = udf_adinicb_write_end,
 126};
 127
 128static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 129                                  unsigned long nr_segs, loff_t ppos)
 130{
 131        ssize_t retval;
 132        struct file *file = iocb->ki_filp;
 133        struct inode *inode = file->f_path.dentry->d_inode;
 134        int err, pos;
 135        size_t count = iocb->ki_left;
 136        struct udf_inode_info *iinfo = UDF_I(inode);
 137
 138        down_write(&iinfo->i_data_sem);
 139        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 140                if (file->f_flags & O_APPEND)
 141                        pos = inode->i_size;
 142                else
 143                        pos = ppos;
 144
 145                if (inode->i_sb->s_blocksize <
 146                                (udf_file_entry_alloc_offset(inode) +
 147                                                pos + count)) {
 148                        err = udf_expand_file_adinicb(inode);
 149                        if (err) {
 150                                udf_debug("udf_expand_adinicb: err=%d\n", err);
 151                                return err;
 152                        }
 153                } else {
 154                        if (pos + count > inode->i_size)
 155                                iinfo->i_lenAlloc = pos + count;
 156                        else
 157                                iinfo->i_lenAlloc = inode->i_size;
 158                        up_write(&iinfo->i_data_sem);
 159                }
 160        } else
 161                up_write(&iinfo->i_data_sem);
 162
 163        retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 164        if (retval > 0)
 165                mark_inode_dirty(inode);
 166
 167        return retval;
 168}
 169
 170long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 171{
 172        struct inode *inode = filp->f_dentry->d_inode;
 173        long old_block, new_block;
 174        int result = -EINVAL;
 175
 176        if (inode_permission(inode, MAY_READ) != 0) {
 177                udf_debug("no permission to access inode %lu\n", inode->i_ino);
 178                result = -EPERM;
 179                goto out;
 180        }
 181
 182        if (!arg) {
 183                udf_debug("invalid argument to udf_ioctl\n");
 184                result = -EINVAL;
 185                goto out;
 186        }
 187
 188        switch (cmd) {
 189        case UDF_GETVOLIDENT:
 190                if (copy_to_user((char __user *)arg,
 191                                 UDF_SB(inode->i_sb)->s_volume_ident, 32))
 192                        result = -EFAULT;
 193                else
 194                        result = 0;
 195                goto out;
 196        case UDF_RELOCATE_BLOCKS:
 197                if (!capable(CAP_SYS_ADMIN)) {
 198                        result = -EACCES;
 199                        goto out;
 200                }
 201                if (get_user(old_block, (long __user *)arg)) {
 202                        result = -EFAULT;
 203                        goto out;
 204                }
 205                result = udf_relocate_blocks(inode->i_sb,
 206                                                old_block, &new_block);
 207                if (result == 0)
 208                        result = put_user(new_block, (long __user *)arg);
 209                goto out;
 210        case UDF_GETEASIZE:
 211                result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 212                goto out;
 213        case UDF_GETEABLOCK:
 214                result = copy_to_user((char __user *)arg,
 215                                      UDF_I(inode)->i_ext.i_data,
 216                                      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 217                goto out;
 218        }
 219
 220out:
 221        return result;
 222}
 223
 224static int udf_release_file(struct inode *inode, struct file *filp)
 225{
 226        if (filp->f_mode & FMODE_WRITE) {
 227                down_write(&UDF_I(inode)->i_data_sem);
 228                udf_discard_prealloc(inode);
 229                udf_truncate_tail_extent(inode);
 230                up_write(&UDF_I(inode)->i_data_sem);
 231        }
 232        return 0;
 233}
 234
 235const struct file_operations udf_file_operations = {
 236        .read                   = do_sync_read,
 237        .aio_read               = generic_file_aio_read,
 238        .unlocked_ioctl         = udf_ioctl,
 239        .open                   = generic_file_open,
 240        .mmap                   = generic_file_mmap,
 241        .write                  = do_sync_write,
 242        .aio_write              = udf_file_aio_write,
 243        .release                = udf_release_file,
 244        .fsync                  = generic_file_fsync,
 245        .splice_read            = generic_file_splice_read,
 246        .llseek                 = generic_file_llseek,
 247};
 248
 249static int udf_setattr(struct dentry *dentry, struct iattr *attr)
 250{
 251        struct inode *inode = dentry->d_inode;
 252        int error;
 253
 254        error = inode_change_ok(inode, attr);
 255        if (error)
 256                return error;
 257
 258        if ((attr->ia_valid & ATTR_SIZE) &&
 259            attr->ia_size != i_size_read(inode)) {
 260                error = udf_setsize(inode, attr->ia_size);
 261                if (error)
 262                        return error;
 263        }
 264
 265        setattr_copy(inode, attr);
 266        mark_inode_dirty(inode);
 267        return 0;
 268}
 269
 270const struct inode_operations udf_file_inode_operations = {
 271        .setattr                = udf_setattr,
 272};
 273
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