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
  40 #include "udf_i.h"
  41 #include "udf_sb.h"
  42
  43 static int udf_adinicb_readpage(struct file *file, struct page * page)
  44 {
  45         struct inode *inode = page->mapping->host;
  46         char *kaddr;
  47
  48         BUG_ON(!PageLocked(page));
  49
  50         kaddr = kmap(page);
  51         memset(kaddr, 0, PAGE_CACHE_SIZE);
  52         memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
  53         flush_dcache_page(page);
  54         SetPageUptodate(page);
  55         kunmap(page);
  56         unlock_page(page);
  57         return 0;
  58 }
  59
  60 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
  61 {
  62         struct inode *inode = page->mapping->host;
  63         char *kaddr;
  64
  65         BUG_ON(!PageLocked(page));
  66
  67         kaddr = kmap(page);
  68         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
  69         mark_inode_dirty(inode);
  70         SetPageUptodate(page);
  71         kunmap(page);
  72         unlock_page(page);
  73         return 0;
  74 }
  75
  76 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  77 {
  78         kmap(page);
  79         return 0;
  80 }
  81
  82 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  83 {
  84         struct inode *inode = page->mapping->host;
  85         char *kaddr = page_address(page);
  86
  87         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  88                 kaddr + offset, to - offset);
  89         mark_inode_dirty(inode);
  90         SetPageUptodate(page);
  91         kunmap(page);
  92         /* only one page here */
  93         if (to > inode->i_size)
  94                 inode->i_size = to;
  95         return 0;
  96 }
  97
  98 struct address_space_operations udf_adinicb_aops = {
  99         .readpage               = udf_adinicb_readpage,
 100         .writepage              = udf_adinicb_writepage,
 101         .sync_page              = block_sync_page,
 102         .prepare_write          = udf_adinicb_prepare_write,
 103         .commit_write           = udf_adinicb_commit_write,
 104 };
 105
 106 static ssize_t udf_file_write(struct file * file, const char __user * buf,
 107         size_t count, loff_t *ppos)
 108 {
 109         ssize_t retval;
 110         struct inode *inode = file->f_dentry->d_inode;
 111         int err, pos;
 112
 113         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 114         {
 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 < (udf_file_entry_alloc_offset(inode) +
 121                         pos + count))
 122                 {
 123                         udf_expand_file_adinicb(inode, pos + count, &err);
 124                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 125                         {
 126                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 127                                 return err;
 128                         }
 129                 }
 130                 else
 131                 {
 132                         if (pos + count > inode->i_size)
 133                                 UDF_I_LENALLOC(inode) = pos + count;
 134                         else
 135                                 UDF_I_LENALLOC(inode) = inode->i_size;
 136                 }
 137         }
 138
 139         retval = generic_file_write(file, buf, count, ppos);
 140
 141         if (retval > 0)
 142                 mark_inode_dirty(inode);
 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         int result = -EINVAL;
 184
 185         if ( file_permission(filp, MAY_READ) != 0 )
 186         {
 187                 udf_debug("no permission to access inode %lu\n",
 188                                                 inode->i_ino);
 189                 return -EPERM;
 190         }
 191
 192         if ( !arg )
 193         {
 194                 udf_debug("invalid argument to udf_ioctl\n");
 195                 return -EINVAL;
 196         }
 197
 198         switch (cmd)
 199         {
 200                 case UDF_GETVOLIDENT:
 201                         return copy_to_user((char __user *)arg,
 202                                 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
 203                 case UDF_RELOCATE_BLOCKS:
 204                 {
 205                         long old, new;
 206
 207                         if (!capable(CAP_SYS_ADMIN)) return -EACCES;
 208                         if (get_user(old, (long __user *)arg)) return -EFAULT;
 209                         if ((result = udf_relocate_blocks(inode->i_sb,
 210                                         old, &new)) == 0)
 211                                 result = put_user(new, (long __user *)arg);
 212
 213                         return result;
 214                 }
 215                 case UDF_GETEASIZE:
 216                         result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 217                         break;
 218
 219                 case UDF_GETEABLOCK:
 220                         result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 221                                 UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
 222                         break;
 223         }
 224
 225         return result;
 226 }
 227
 228 /*
 229  * udf_release_file
 230  *
 231  * PURPOSE
 232  *  Called when all references to the file are closed
 233  *
 234  * DESCRIPTION
 235  *  Discard prealloced blocks
 236  *
 237  * HISTORY
 238  *
 239  */
 240 static int udf_release_file(struct inode * inode, struct file * filp)
 241 {
 242         if (filp->f_mode & FMODE_WRITE)
 243         {
 244                 lock_kernel();
 245                 udf_discard_prealloc(inode);
 246                 unlock_kernel();
 247         }
 248         return 0;
 249 }
 250
 251 const struct file_operations udf_file_operations = {
 252         .read                   = generic_file_read,
 253         .ioctl                  = udf_ioctl,
 254         .open                   = generic_file_open,
 255         .mmap                   = generic_file_mmap,
 256         .write                  = udf_file_write,
 257         .release                = udf_release_file,
 258         .fsync                  = udf_fsync_file,
 259         .sendfile               = generic_file_sendfile,
 260 };
 261
 262 struct inode_operations udf_file_inode_operations = {
 263         .truncate               = udf_truncate,
 264 };