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/errno.h>
  35 #include <linux/smp_lock.h>
  36 #include <linux/pagemap.h>
  37 #include <linux/buffer_head.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
  47         BUG_ON(!PageLocked(page));
  48
  49         kaddr = kmap(page);
  50         memset(kaddr, 0, PAGE_CACHE_SIZE);
  51         memcpy(kaddr, UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), inode->i_size);
  52         flush_dcache_page(page);
  53         SetPageUptodate(page);
  54         kunmap(page);
  55         unlock_page(page);
  56         return 0;
  57 }
  58
  59 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
  60 {
  61         struct inode *inode = page->mapping->host;
  62         char *kaddr;
  63
  64         BUG_ON(!PageLocked(page));
  65
  66         kaddr = kmap(page);
  67         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
  68         mark_inode_dirty(inode);
  69         SetPageUptodate(page);
  70         kunmap(page);
  71         unlock_page(page);
  72         return 0;
  73 }
  74
  75 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  76 {
  77         kmap(page);
  78         return 0;
  79 }
  80
  81 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  82 {
  83         struct inode *inode = page->mapping->host;
  84         char *kaddr = page_address(page);
  85
  86         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  87                 kaddr + offset, to - offset);
  88         mark_inode_dirty(inode);
  89         SetPageUptodate(page);
  90         kunmap(page);
  91         /* only one page here */
  92         if (to > inode->i_size)
  93                 inode->i_size = to;
  94         return 0;
  95 }
  96
  97 struct address_space_operations udf_adinicb_aops = {
  98         .readpage               = udf_adinicb_readpage,
  99         .writepage              = udf_adinicb_writepage,
 100         .sync_page              = block_sync_page,
 101         .prepare_write          = udf_adinicb_prepare_write,
 102         .commit_write           = udf_adinicb_commit_write,
 103 };
 104
 105 static ssize_t udf_file_write(struct file * file, const char __user * buf,
 106         size_t count, loff_t *ppos)
 107 {
 108         ssize_t retval;
 109         struct inode *inode = file->f_dentry->d_inode;
 110         int err, pos;
 111
 112         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 113         {
 114                 if (file->f_flags & O_APPEND)
 115                         pos = inode->i_size;
 116                 else
 117                         pos = *ppos;
 118
 119                 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
 120                         pos + count))
 121                 {
 122                         udf_expand_file_adinicb(inode, pos + count, &err);
 123                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 124                         {
 125                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 126                                 return err;
 127                         }
 128                 }
 129                 else
 130                 {
 131                         if (pos + count > inode->i_size)
 132                                 UDF_I_LENALLOC(inode) = pos + count;
 133                         else
 134                                 UDF_I_LENALLOC(inode) = inode->i_size;
 135                 }
 136         }
 137
 138         retval = generic_file_write(file, buf, count, ppos);
 139
 140         if (retval > 0)
 141                 mark_inode_dirty(inode);
 142         return retval;
 143 }
 144
 145 /*
 146  * udf_ioctl
 147  *
 148  * PURPOSE
 149  *      Issue an ioctl.
 150  *
 151  * DESCRIPTION
 152  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 153  *      available, and the ioctl cannot be handled without filesystem help.
 154  *
 155  *      sys_ioctl() handles these ioctls that apply only to regular files:
 156  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 157  *      These ioctls are also handled by sys_ioctl():
 158  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 159  *      All other ioctls are passed to the filesystem.
 160  *
 161  *      Refer to sys_ioctl() in fs/ioctl.c
 162  *      sys_ioctl() -> .
 163  *
 164  * PRE-CONDITIONS
 165  *      inode                   Pointer to inode that ioctl was issued on.
 166  *      filp                    Pointer to file that ioctl was issued on.
 167  *      cmd                     The ioctl command.
 168  *      arg                     The ioctl argument [can be interpreted as a
 169  *                              user-space pointer if desired].
 170  *
 171  * POST-CONDITIONS
 172  *      <return>                Success (>=0) or an error code (<=0) that
 173  *                              sys_ioctl() will return.
 174  *
 175  * HISTORY
 176  *      July 1, 1997 - Andrew E. Mileski
 177  *      Written, tested, and released.
 178  */
 179 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 180         unsigned long arg)
 181 {
 182         int result = -EINVAL;
 183
 184         if ( file_permission(filp, MAY_READ) != 0 )
 185         {
 186                 udf_debug("no permission to access inode %lu\n",
 187                                                 inode->i_ino);
 188                 return -EPERM;
 189         }
 190
 191         if ( !arg )
 192         {
 193                 udf_debug("invalid argument to udf_ioctl\n");
 194                 return -EINVAL;
 195         }
 196
 197         switch (cmd)
 198         {
 199                 case UDF_GETVOLIDENT:
 200                         return copy_to_user((char __user *)arg,
 201                                 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
 202                 case UDF_RELOCATE_BLOCKS:
 203                 {
 204                         long old, new;
 205
 206                         if (!capable(CAP_SYS_ADMIN)) return -EACCES;
 207                         if (get_user(old, (long __user *)arg)) return -EFAULT;
 208                         if ((result = udf_relocate_blocks(inode->i_sb,
 209                                         old, &new)) == 0)
 210                                 result = put_user(new, (long __user *)arg);
 211
 212                         return result;
 213                 }
 214                 case UDF_GETEASIZE:
 215                         result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 216                         break;
 217
 218                 case UDF_GETEABLOCK:
 219                         result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 220                                 UDF_I_LENEATTR(inode)) ? -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         {
 243                 lock_kernel();
 244                 udf_discard_prealloc(inode);
 245                 unlock_kernel();
 246         }
 247         return 0;
 248 }
 249
 250 struct file_operations udf_file_operations = {
 251         .read                   = generic_file_read,
 252         .ioctl                  = udf_ioctl,
 253         .open                   = generic_file_open,
 254         .mmap                   = generic_file_mmap,
 255         .write                  = udf_file_write,
 256         .release                = udf_release_file,
 257         .fsync                  = udf_fsync_file,
 258         .sendfile               = generic_file_sendfile,
 259 };
 260
 261 struct inode_operations udf_file_inode_operations = {
 262         .truncate               = udf_truncate,
 263 };