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 <linux/udf_fs.h>
  31 #include <asm/uaccess.h>
  32 #include <linux/kernel.h>
  33 #include <linux/string.h> /* memset */
  34 #include <linux/capability.h>
  35 #include <linux/errno.h>
  36 #include <linux/smp_lock.h>
  37 #include <linux/pagemap.h>
  38 #include <linux/buffer_head.h>
  39 #include <linux/aio.h>
  40
  41 #include "udf_i.h"
  42 #include "udf_sb.h"
  43
  44 static int udf_adinicb_readpage(struct file *file, struct page *page)
  45 {
  46         struct inode *inode = page->mapping->host;
  47         char *kaddr;
  48
  49         BUG_ON(!PageLocked(page));
  50
  51         kaddr = kmap(page);
  52         memset(kaddr, 0, PAGE_CACHE_SIZE);
  53         memcpy(kaddr, UDF_I(inode)->i_ext.i_data + UDF_I(inode)->i_lenEAttr,
  54                                                                 inode->i_size);
  55         flush_dcache_page(page);
  56         SetPageUptodate(page);
  57         kunmap(page);
  58         unlock_page(page);
  59
  60         return 0;
  61 }
  62
  63 static int udf_adinicb_writepage(struct page *page,
  64                                  struct writeback_control *wbc)
  65 {
  66         struct inode *inode = page->mapping->host;
  67         char *kaddr;
  68
  69         BUG_ON(!PageLocked(page));
  70
  71         kaddr = kmap(page);
  72         memcpy(UDF_I(inode)->i_ext.i_data + UDF_I(inode)->i_lenEAttr, kaddr,
  73                                                                 inode->i_size);
  74         mark_inode_dirty(inode);
  75         SetPageUptodate(page);
  76         kunmap(page);
  77         unlock_page(page);
  78
  79         return 0;
  80 }
  81
  82 static int udf_adinicb_write_end(struct file *file,
  83                         struct address_space *mapping,
  84                         loff_t pos, unsigned len, unsigned copied,
  85                         struct page *page, void *fsdata)
  86 {
  87         struct inode *inode = mapping->host;
  88         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  89         char *kaddr;
  90
  91         kaddr = kmap_atomic(page, KM_USER0);
  92         memcpy(UDF_I(inode)->i_ext.i_data + UDF_I(inode)->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
  99 const 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
 107 static 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
 116         if (UDF_I(inode)->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                         udf_expand_file_adinicb(inode, pos + count, &err);
 126                         if (UDF_I(inode)->i_alloc_type ==
 127                                                         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                                 UDF_I(inode)->i_lenAlloc = pos + count;
 134                         else
 135                                 UDF_I(inode)->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
 146 /*
 147  * udf_ioctl
 148  *
 149  * PURPOSE
 150  *      Issue an ioctl.
 151  *
 152  * DESCRIPTION
 153  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 154  *      available, and the ioctl cannot be handled without filesystem help.
 155  *
 156  *      sys_ioctl() handles these ioctls that apply only to regular files:
 157  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 158  *      These ioctls are also handled by sys_ioctl():
 159  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 160  *      All other ioctls are passed to the filesystem.
 161  *
 162  *      Refer to sys_ioctl() in fs/ioctl.c
 163  *      sys_ioctl() -> .
 164  *
 165  * PRE-CONDITIONS
 166  *      inode                   Pointer to inode that ioctl was issued on.
 167  *      filp                    Pointer to file that ioctl was issued on.
 168  *      cmd                     The ioctl command.
 169  *      arg                     The ioctl argument [can be interpreted as a
 170  *                              user-space pointer if desired].
 171  *
 172  * POST-CONDITIONS
 173  *      <return>                Success (>=0) or an error code (<=0) that
 174  *                              sys_ioctl() will return.
 175  *
 176  * HISTORY
 177  *      July 1, 1997 - Andrew E. Mileski
 178  *      Written, tested, and released.
 179  */
 180 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 181               unsigned long arg)
 182 {
 183         long old_block, new_block;
 184         int result = -EINVAL;
 185
 186         if (file_permission(filp, MAY_READ) != 0) {
 187                 udf_debug("no permission to access inode %lu\n",
 188                           inode->i_ino);
 189                 return -EPERM;
 190         }
 191
 192         if (!arg) {
 193                 udf_debug("invalid argument to udf_ioctl\n");
 194                 return -EINVAL;
 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                         return -EFAULT;
 202                 else
 203                         return 0;
 204         case UDF_RELOCATE_BLOCKS:
 205                 if (!capable(CAP_SYS_ADMIN))
 206                         return -EACCES;
 207                 if (get_user(old_block, (long __user *)arg))
 208                         return -EFAULT;
 209                 result = udf_relocate_blocks(inode->i_sb,
 210                                                 old_block, &new_block);
 211                 if (result == 0)
 212                         result = put_user(new_block, (long __user *)arg);
 213                 return result;
 214         case UDF_GETEASIZE:
 215                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 216                 break;
 217         case UDF_GETEABLOCK:
 218                 result = copy_to_user((char __user *)arg,
 219                                       UDF_I(inode)->i_ext.i_data,
 220                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 221                 break;
 222         }
 223
 224         return result;
 225 }
 226
 227 /*
 228  * udf_release_file
 229  *
 230  * PURPOSE
 231  *  Called when all references to the file are closed
 232  *
 233  * DESCRIPTION
 234  *  Discard prealloced blocks
 235  *
 236  * HISTORY
 237  *
 238  */
 239 static int udf_release_file(struct inode *inode, struct file *filp)
 240 {
 241         if (filp->f_mode & FMODE_WRITE) {
 242                 lock_kernel();
 243                 udf_discard_prealloc(inode);
 244                 unlock_kernel();
 245         }
 246         return 0;
 247 }
 248
 249 const struct file_operations udf_file_operations = {
 250         .read                   = do_sync_read,
 251         .aio_read               = generic_file_aio_read,
 252         .ioctl                  = udf_ioctl,
 253         .open                   = generic_file_open,
 254         .mmap                   = generic_file_mmap,
 255         .write                  = do_sync_write,
 256         .aio_write              = udf_file_aio_write,
 257         .release                = udf_release_file,
 258         .fsync                  = udf_fsync_file,
 259         .splice_read            = generic_file_splice_read,
 260 };
 261
 262 const struct inode_operations udf_file_inode_operations = {
 263         .truncate = udf_truncate,
 264 };