fs/udf/file.c

   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
  42 static 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
  61 static 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
  80 static 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
  98 const struct address_space_operations udf_adinicb_aops = {
  99         .readpage       = udf_adinicb_readpage,
 100         .writepage      = udf_adinicb_writepage,
 101         .sync_page      = block_sync_page,
 102         .write_begin = simple_write_begin,
 103         .write_end = udf_adinicb_write_end,
 104 };
 105
 106 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 107                                   unsigned long nr_segs, loff_t ppos)
 108 {
 109         ssize_t retval;
 110         struct file *file = iocb->ki_filp;
 111         struct inode *inode = file->f_path.dentry->d_inode;
 112         int err, pos;
 113         size_t count = iocb->ki_left;
 114         struct udf_inode_info *iinfo = UDF_I(inode);
 115
 116         down_write(&iinfo->i_data_sem);
 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                                 up_write(&iinfo->i_data_sem);
 130                                 return err;
 131                         }
 132                 } else {
 133                         if (pos + count > inode->i_size)
 134                                 iinfo->i_lenAlloc = pos + count;
 135                         else
 136                                 iinfo->i_lenAlloc = inode->i_size;
 137                 }
 138         }
 139         up_write(&iinfo->i_data_sem);
 140
 141         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 142         if (retval > 0)
 143                 mark_inode_dirty(inode);
 144
 145         return retval;
 146 }
 147
 148 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 149 {
 150         struct inode *inode = filp->f_dentry->d_inode;
 151         long old_block, new_block;
 152         int result = -EINVAL;
 153
 154         if (file_permission(filp, MAY_READ) != 0) {
 155                 udf_debug("no permission to access inode %lu\n", inode->i_ino);
 156                 result = -EPERM;
 157                 goto out;
 158         }
 159
 160         if (!arg) {
 161                 udf_debug("invalid argument to udf_ioctl\n");
 162                 result = -EINVAL;
 163                 goto out;
 164         }
 165
 166         switch (cmd) {
 167         case UDF_GETVOLIDENT:
 168                 if (copy_to_user((char __user *)arg,
 169                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
 170                         result = -EFAULT;
 171                 else
 172                         result = 0;
 173                 goto out;
 174         case UDF_RELOCATE_BLOCKS:
 175                 if (!capable(CAP_SYS_ADMIN)) {
 176                         result = -EACCES;
 177                         goto out;
 178                 }
 179                 if (get_user(old_block, (long __user *)arg)) {
 180                         result = -EFAULT;
 181                         goto out;
 182                 }
 183                 result = udf_relocate_blocks(inode->i_sb,
 184                                                 old_block, &new_block);
 185                 if (result == 0)
 186                         result = put_user(new_block, (long __user *)arg);
 187                 goto out;
 188         case UDF_GETEASIZE:
 189                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 190                 goto out;
 191         case UDF_GETEABLOCK:
 192                 result = copy_to_user((char __user *)arg,
 193                                       UDF_I(inode)->i_ext.i_data,
 194                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 195                 goto out;
 196         }
 197
 198 out:
 199         return result;
 200 }
 201
 202 static int udf_release_file(struct inode *inode, struct file *filp)
 203 {
 204         if (filp->f_mode & FMODE_WRITE) {
 205                 mutex_lock(&inode->i_mutex);
 206                 down_write(&UDF_I(inode)->i_data_sem);
 207                 udf_discard_prealloc(inode);
 208                 udf_truncate_tail_extent(inode);
 209                 up_write(&UDF_I(inode)->i_data_sem);
 210                 mutex_unlock(&inode->i_mutex);
 211         }
 212         return 0;
 213 }
 214
 215 const struct file_operations udf_file_operations = {
 216         .read                   = do_sync_read,
 217         .aio_read               = generic_file_aio_read,
 218         .unlocked_ioctl         = udf_ioctl,
 219         .open                   = generic_file_open,
 220         .mmap                   = generic_file_mmap,
 221         .write                  = do_sync_write,
 222         .aio_write              = udf_file_aio_write,
 223         .release                = udf_release_file,
 224         .fsync                  = generic_file_fsync,
 225         .splice_read            = generic_file_splice_read,
 226         .llseek                 = generic_file_llseek,
 227 };
 228
 229 static int udf_setattr(struct dentry *dentry, struct iattr *attr)
 230 {
 231         struct inode *inode = dentry->d_inode;
 232         int error;
 233
 234         error = inode_change_ok(inode, attr);
 235         if (error)
 236                 return error;
 237
 238         if ((attr->ia_valid & ATTR_SIZE) &&
 239             attr->ia_size != i_size_read(inode)) {
 240                 error = vmtruncate(inode, attr->ia_size);
 241                 if (error)
 242                         return error;
 243         }
 244
 245         setattr_copy(inode, attr);
 246         mark_inode_dirty(inode);
 247         return 0;
 248 }
 249
 250 const struct inode_operations udf_file_inode_operations = {
 251         .setattr                = udf_setattr,
 252         .truncate               = udf_truncate,
 253 };