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
 121static ssize_t udf_adinicb_direct_IO(int rw, struct kiocb *iocb,
 122                                     const struct iovec *iov,
 123                                     loff_t offset, unsigned long nr_segs)
 124{
 125        /* Fallback to buffered I/O. */
 126        return 0;
 127}
 128
 129const struct address_space_operations udf_adinicb_aops = {
 130        .readpage       = udf_adinicb_readpage,
 131        .writepage      = udf_adinicb_writepage,
 132        .write_begin    = udf_adinicb_write_begin,
 133        .write_end      = udf_adinicb_write_end,
 134        .direct_IO      = udf_adinicb_direct_IO,
 135};
 136
 137static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 138                                  unsigned long nr_segs, loff_t ppos)
 139{
 140        ssize_t retval;
 141        struct file *file = iocb->ki_filp;
 142        struct inode *inode = file->f_path.dentry->d_inode;
 143        int err, pos;
 144        size_t count = iocb->ki_left;
 145        struct udf_inode_info *iinfo = UDF_I(inode);
 146
 147        down_write(&iinfo->i_data_sem);
 148        if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 149                if (file->f_flags & O_APPEND)
 150                        pos = inode->i_size;
 151                else
 152                        pos = ppos;
 153
 154                if (inode->i_sb->s_blocksize <
 155                                (udf_file_entry_alloc_offset(inode) +
 156                                                pos + count)) {
 157                        err = udf_expand_file_adinicb(inode);
 158                        if (err) {
 159                                udf_debug("udf_expand_adinicb: err=%d\n", err);
 160                                return err;
 161                        }
 162                } else {
 163                        if (pos + count > inode->i_size)
 164                                iinfo->i_lenAlloc = pos + count;
 165                        else
 166                                iinfo->i_lenAlloc = inode->i_size;
 167                        up_write(&iinfo->i_data_sem);
 168                }
 169        } else
 170                up_write(&iinfo->i_data_sem);
 171
 172        retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 173        if (retval > 0)
 174                mark_inode_dirty(inode);
 175
 176        return retval;
 177}
 178
 179long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 180{
 181        struct inode *inode = filp->f_dentry->d_inode;
 182        long old_block, new_block;
 183        int result = -EINVAL;
 184
 185        if (inode_permission(inode, MAY_READ) != 0) {
 186                udf_debug("no permission to access inode %lu\n", inode->i_ino);
 187                result = -EPERM;
 188                goto out;
 189        }
 190
 191        if (!arg) {
 192                udf_debug("invalid argument to udf_ioctl\n");
 193                result = -EINVAL;
 194                goto out;
 195        }
 196
 197        switch (cmd) {
 198        case UDF_GETVOLIDENT:
 199                if (copy_to_user((char __user *)arg,
 200                                 UDF_SB(inode->i_sb)->s_volume_ident, 32))
 201                        result = -EFAULT;
 202                else
 203                        result = 0;
 204                goto out;
 205        case UDF_RELOCATE_BLOCKS:
 206                if (!capable(CAP_SYS_ADMIN)) {
 207                        result = -EACCES;
 208                        goto out;
 209                }
 210                if (get_user(old_block, (long __user *)arg)) {
 211                        result = -EFAULT;
 212                        goto out;
 213                }
 214                result = udf_relocate_blocks(inode->i_sb,
 215                                                old_block, &new_block);
 216                if (result == 0)
 217                        result = put_user(new_block, (long __user *)arg);
 218                goto out;
 219        case UDF_GETEASIZE:
 220                result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 221                goto out;
 222        case UDF_GETEABLOCK:
 223                result = copy_to_user((char __user *)arg,
 224                                      UDF_I(inode)->i_ext.i_data,
 225                                      UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 226                goto out;
 227        }
 228
 229out:
 230        return result;
 231}
 232
 233static int udf_release_file(struct inode *inode, struct file *filp)
 234{
 235        if (filp->f_mode & FMODE_WRITE) {
 236                down_write(&UDF_I(inode)->i_data_sem);
 237                udf_discard_prealloc(inode);
 238                udf_truncate_tail_extent(inode);
 239                up_write(&UDF_I(inode)->i_data_sem);
 240        }
 241        return 0;
 242}
 243
 244const struct file_operations udf_file_operations = {
 245        .read                   = do_sync_read,
 246        .aio_read               = generic_file_aio_read,
 247        .unlocked_ioctl         = udf_ioctl,
 248        .open                   = generic_file_open,
 249        .mmap                   = generic_file_mmap,
 250        .write                  = do_sync_write,
 251        .aio_write              = udf_file_aio_write,
 252        .release                = udf_release_file,
 253        .fsync                  = generic_file_fsync,
 254        .splice_read            = generic_file_splice_read,
 255        .llseek                 = generic_file_llseek,
 256};
 257
 258static int udf_setattr(struct dentry *dentry, struct iattr *attr)
 259{
 260        struct inode *inode = dentry->d_inode;
 261        int error;
 262
 263        error = inode_change_ok(inode, attr);
 264        if (error)
 265                return error;
 266
 267        if ((attr->ia_valid & ATTR_SIZE) &&
 268            attr->ia_size != i_size_read(inode)) {
 269                error = udf_setsize(inode, attr->ia_size);
 270                if (error)
 271                        return error;
 272        }
 273
 274        setattr_copy(inode, attr);
 275        mark_inode_dirty(inode);
 276        return 0;
 277}
 278
 279const struct inode_operations udf_file_inode_operations = {
 280        .setattr                = udf_setattr,
 281};
 282
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