SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
  54         flush_dcache_page(page);
  55         SetPageUptodate(page);
  56         kunmap(page);
  57         unlock_page(page);
  58
  59         return 0;
  60 }
  61
  62 static int udf_adinicb_writepage(struct page *page,
  63                                  struct writeback_control *wbc)
  64 {
  65         struct inode *inode = page->mapping->host;
  66         char *kaddr;
  67
  68         BUG_ON(!PageLocked(page));
  69
  70         kaddr = kmap(page);
  71         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), 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
  89         kaddr = kmap_atomic(page, KM_USER0);
  90         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  91                 kaddr + offset, copied);
  92         kunmap_atomic(kaddr, KM_USER0);
  93
  94         return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  95 }
  96
  97 const struct address_space_operations udf_adinicb_aops = {
  98         .readpage       = udf_adinicb_readpage,
  99         .writepage      = udf_adinicb_writepage,
 100         .sync_page      = block_sync_page,
 101         .write_begin = simple_write_begin,
 102         .write_end = udf_adinicb_write_end,
 103 };
 104
 105 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 106                                   unsigned long nr_segs, loff_t ppos)
 107 {
 108         ssize_t retval;
 109         struct file *file = iocb->ki_filp;
 110         struct inode *inode = file->f_path.dentry->d_inode;
 111         int err, pos;
 112         size_t count = iocb->ki_left;
 113
 114         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
 115                 if (file->f_flags & O_APPEND)
 116                         pos = inode->i_size;
 117                 else
 118                         pos = ppos;
 119
 120                 if (inode->i_sb->s_blocksize <
 121                                 (udf_file_entry_alloc_offset(inode) +
 122                                                 pos + count)) {
 123                         udf_expand_file_adinicb(inode, pos + count, &err);
 124                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
 125                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 126                                 return err;
 127                         }
 128                 } else {
 129                         if (pos + count > inode->i_size)
 130                                 UDF_I_LENALLOC(inode) = pos + count;
 131                         else
 132                                 UDF_I_LENALLOC(inode) = inode->i_size;
 133                 }
 134         }
 135
 136         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 137         if (retval > 0)
 138                 mark_inode_dirty(inode);
 139
 140         return retval;
 141 }
 142
 143 /*
 144  * udf_ioctl
 145  *
 146  * PURPOSE
 147  *      Issue an ioctl.
 148  *
 149  * DESCRIPTION
 150  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 151  *      available, and the ioctl cannot be handled without filesystem help.
 152  *
 153  *      sys_ioctl() handles these ioctls that apply only to regular files:
 154  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 155  *      These ioctls are also handled by sys_ioctl():
 156  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 157  *      All other ioctls are passed to the filesystem.
 158  *
 159  *      Refer to sys_ioctl() in fs/ioctl.c
 160  *      sys_ioctl() -> .
 161  *
 162  * PRE-CONDITIONS
 163  *      inode                   Pointer to inode that ioctl was issued on.
 164  *      filp                    Pointer to file that ioctl was issued on.
 165  *      cmd                     The ioctl command.
 166  *      arg                     The ioctl argument [can be interpreted as a
 167  *                              user-space pointer if desired].
 168  *
 169  * POST-CONDITIONS
 170  *      <return>                Success (>=0) or an error code (<=0) that
 171  *                              sys_ioctl() will return.
 172  *
 173  * HISTORY
 174  *      July 1, 1997 - Andrew E. Mileski
 175  *      Written, tested, and released.
 176  */
 177 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 178               unsigned long arg)
 179 {
 180         long old_block, new_block;
 181         int result = -EINVAL;
 182
 183         if (file_permission(filp, MAY_READ) != 0) {
 184                 udf_debug("no permission to access inode %lu\n",
 185                           inode->i_ino);
 186                 return -EPERM;
 187         }
 188
 189         if (!arg) {
 190                 udf_debug("invalid argument to udf_ioctl\n");
 191                 return -EINVAL;
 192         }
 193
 194         switch (cmd) {
 195         case UDF_GETVOLIDENT:
 196                 if (copy_to_user((char __user *)arg,
 197                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
 198                         return -EFAULT;
 199                 else
 200                         return 0;
 201         case UDF_RELOCATE_BLOCKS:
 202                 if (!capable(CAP_SYS_ADMIN))
 203                         return -EACCES;
 204                 if (get_user(old_block, (long __user *)arg))
 205                         return -EFAULT;
 206                 result = udf_relocate_blocks(inode->i_sb,
 207                                                 old_block, &new_block);
 208                 if (result == 0)
 209                         result = put_user(new_block, (long __user *)arg);
 210                 return result;
 211         case UDF_GETEASIZE:
 212                 result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 213                 break;
 214         case UDF_GETEABLOCK:
 215                 result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 216                                       UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
 217                 break;
 218         }
 219
 220         return result;
 221 }
 222
 223 /*
 224  * udf_release_file
 225  *
 226  * PURPOSE
 227  *  Called when all references to the file are closed
 228  *
 229  * DESCRIPTION
 230  *  Discard prealloced blocks
 231  *
 232  * HISTORY
 233  *
 234  */
 235 static int udf_release_file(struct inode *inode, struct file *filp)
 236 {
 237         if (filp->f_mode & FMODE_WRITE) {
 238                 lock_kernel();
 239                 udf_discard_prealloc(inode);
 240                 unlock_kernel();
 241         }
 242         return 0;
 243 }
 244
 245 const struct file_operations udf_file_operations = {
 246         .read                   = do_sync_read,
 247         .aio_read               = generic_file_aio_read,
 248         .ioctl                  = udf_ioctl,
 249         .open                   = generic_file_open,
 250         .mmap                   = generic_file_mmap,
 251         .write                  = do_sync_write,
 252         .aio_write              = udf_file_aio_write,
 253         .release                = udf_release_file,
 254         .fsync                  = udf_fsync_file,
 255         .splice_read            = generic_file_splice_read,
 256 };
 257
 258 const struct inode_operations udf_file_inode_operations = {
 259         .truncate = udf_truncate,
 260 };