fs/udf/file.c

   1 /*
   2  * file.c
   3  *
   4  * PURPOSE
   5  *  File handling routines for the OSTA-UDF(tm) filesystem.
   6  *
   7  * CONTACTS
   8  *  E-mail regarding any portion of the Linux UDF file system should be
   9  *  directed to the development team mailing list (run by majordomo):
  10  *    linux_udf@hpesjro.fc.hp.com
  11  *
  12  * COPYRIGHT
  13  *  This file is distributed under the terms of the GNU General Public
  14  *  License (GPL). Copies of the GPL can be obtained from:
  15  *    ftp://prep.ai.mit.edu/pub/gnu/GPL
  16  *  Each contributing author retains all rights to their own work.
  17  *
  18  *  (C) 1998-1999 Dave Boynton
  19  *  (C) 1998-2004 Ben Fennema
  20  *  (C) 1999-2000 Stelias Computing Inc
  21  *
  22  * HISTORY
  23  *
  24  *  10/02/98 dgb  Attempt to integrate into udf.o
  25  *  10/07/98      Switched to using generic_readpage, etc., like isofs
  26  *                And it works!
  27  *  12/06/98 blf  Added udf_file_read. uses generic_file_read for all cases but
  28  *                ICBTAG_FLAG_AD_IN_ICB.
  29  *  04/06/99      64 bit file handling on 32 bit systems taken from ext2 file.c
  30  *  05/12/99      Preliminary file write support
  31  */
  32
  33 #include "udfdecl.h"
  34 #include <linux/fs.h>
  35 #include <linux/udf_fs.h>
  36 #include <asm/uaccess.h>
  37 #include <linux/kernel.h>
  38 #include <linux/string.h> /* memset */
  39 #include <linux/errno.h>
  40 #include <linux/smp_lock.h>
  41 #include <linux/pagemap.h>
  42 #include <linux/buffer_head.h>
  43
  44 #include "udf_i.h"
  45 #include "udf_sb.h"
  46
  47 static int udf_adinicb_readpage(struct file *file, struct page * page)
  48 {
  49         struct inode *inode = page->mapping->host;
  50         char *kaddr;
  51
  52         BUG_ON(!PageLocked(page));
  53
  54         kaddr = kmap(page);
  55         memset(kaddr, 0, PAGE_CACHE_SIZE);
  56         memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
  57         flush_dcache_page(page);
  58         SetPageUptodate(page);
  59         kunmap(page);
  60         unlock_page(page);
  61         return 0;
  62 }
  63
  64 static int udf_adinicb_writepage(struct page *page, 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_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
  73         mark_inode_dirty(inode);
  74         SetPageUptodate(page);
  75         kunmap(page);
  76         unlock_page(page);
  77         return 0;
  78 }
  79
  80 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  81 {
  82         kmap(page);
  83         return 0;
  84 }
  85
  86 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  87 {
  88         struct inode *inode = page->mapping->host;
  89         char *kaddr = page_address(page);
  90
  91         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  92                 kaddr + offset, to - offset);
  93         mark_inode_dirty(inode);
  94         SetPageUptodate(page);
  95         kunmap(page);
  96         /* only one page here */
  97         if (to > inode->i_size)
  98                 inode->i_size = to;
  99         return 0;
 100 }
 101
 102 struct address_space_operations udf_adinicb_aops = {
 103         .readpage               = udf_adinicb_readpage,
 104         .writepage              = udf_adinicb_writepage,
 105         .sync_page              = block_sync_page,
 106         .prepare_write          = udf_adinicb_prepare_write,
 107         .commit_write           = udf_adinicb_commit_write,
 108 };
 109
 110 static ssize_t udf_file_write(struct file * file, const char __user * buf,
 111         size_t count, loff_t *ppos)
 112 {
 113         ssize_t retval;
 114         struct inode *inode = file->f_dentry->d_inode;
 115         int err, pos;
 116
 117         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 118         {
 119                 if (file->f_flags & O_APPEND)
 120                         pos = inode->i_size;
 121                 else
 122                         pos = *ppos;
 123
 124                 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
 125                         pos + count))
 126                 {
 127                         udf_expand_file_adinicb(inode, pos + count, &err);
 128                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 129                         {
 130                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 131                                 return err;
 132                         }
 133                 }
 134                 else
 135                 {
 136                         if (pos + count > inode->i_size)
 137                                 UDF_I_LENALLOC(inode) = pos + count;
 138                         else
 139                                 UDF_I_LENALLOC(inode) = inode->i_size;
 140                 }
 141         }
 142
 143         retval = generic_file_write(file, buf, count, ppos);
 144
 145         if (retval > 0)
 146                 mark_inode_dirty(inode);
 147         return retval;
 148 }
 149
 150 /*
 151  * udf_ioctl
 152  *
 153  * PURPOSE
 154  *      Issue an ioctl.
 155  *
 156  * DESCRIPTION
 157  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 158  *      available, and the ioctl cannot be handled without filesystem help.
 159  *
 160  *      sys_ioctl() handles these ioctls that apply only to regular files:
 161  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 162  *      These ioctls are also handled by sys_ioctl():
 163  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 164  *      All other ioctls are passed to the filesystem.
 165  *
 166  *      Refer to sys_ioctl() in fs/ioctl.c
 167  *      sys_ioctl() -> .
 168  *
 169  * PRE-CONDITIONS
 170  *      inode                   Pointer to inode that ioctl was issued on.
 171  *      filp                    Pointer to file that ioctl was issued on.
 172  *      cmd                     The ioctl command.
 173  *      arg                     The ioctl argument [can be interpreted as a
 174  *                              user-space pointer if desired].
 175  *
 176  * POST-CONDITIONS
 177  *      <return>                Success (>=0) or an error code (<=0) that
 178  *                              sys_ioctl() will return.
 179  *
 180  * HISTORY
 181  *      July 1, 1997 - Andrew E. Mileski
 182  *      Written, tested, and released.
 183  */
 184 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 185         unsigned long arg)
 186 {
 187         int result = -EINVAL;
 188
 189         if ( file_permission(filp, MAY_READ) != 0 )
 190         {
 191                 udf_debug("no permission to access inode %lu\n",
 192                                                 inode->i_ino);
 193                 return -EPERM;
 194         }
 195
 196         if ( !arg )
 197         {
 198                 udf_debug("invalid argument to udf_ioctl\n");
 199                 return -EINVAL;
 200         }
 201
 202         switch (cmd)
 203         {
 204                 case UDF_GETVOLIDENT:
 205                         return copy_to_user((char __user *)arg,
 206                                 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
 207                 case UDF_RELOCATE_BLOCKS:
 208                 {
 209                         long old, new;
 210
 211                         if (!capable(CAP_SYS_ADMIN)) return -EACCES;
 212                         if (get_user(old, (long __user *)arg)) return -EFAULT;
 213                         if ((result = udf_relocate_blocks(inode->i_sb,
 214                                         old, &new)) == 0)
 215                                 result = put_user(new, (long __user *)arg);
 216
 217                         return result;
 218                 }
 219                 case UDF_GETEASIZE:
 220                         result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 221                         break;
 222
 223                 case UDF_GETEABLOCK:
 224                         result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 225                                 UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
 226                         break;
 227         }
 228
 229         return result;
 230 }
 231
 232 /*
 233  * udf_release_file
 234  *
 235  * PURPOSE
 236  *  Called when all references to the file are closed
 237  *
 238  * DESCRIPTION
 239  *  Discard prealloced blocks
 240  *
 241  * HISTORY
 242  *
 243  */
 244 static int udf_release_file(struct inode * inode, struct file * filp)
 245 {
 246         if (filp->f_mode & FMODE_WRITE)
 247         {
 248                 lock_kernel();
 249                 udf_discard_prealloc(inode);
 250                 unlock_kernel();
 251         }
 252         return 0;
 253 }
 254
 255 struct file_operations udf_file_operations = {
 256         .read                   = generic_file_read,
 257         .ioctl                  = udf_ioctl,
 258         .open                   = generic_file_open,
 259         .mmap                   = generic_file_mmap,
 260         .write                  = udf_file_write,
 261         .release                = udf_release_file,
 262         .fsync                  = udf_fsync_file,
 263         .sendfile               = generic_file_sendfile,
 264 };
 265
 266 struct inode_operations udf_file_inode_operations = {
 267         .truncate               = udf_truncate,
 268 };