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, struct writeback_control *wbc)
  63 {
  64         struct inode *inode = page->mapping->host;
  65         char *kaddr;
  66
  67         BUG_ON(!PageLocked(page));
  68
  69         kaddr = kmap(page);
  70         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
  71         mark_inode_dirty(inode);
  72         SetPageUptodate(page);
  73         kunmap(page);
  74         unlock_page(page);
  75
  76         return 0;
  77 }
  78
  79 static int udf_adinicb_prepare_write(struct file *file, struct page *page,
  80                                      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,
  87                                     unsigned offset, unsigned to)
  88 {
  89         struct inode *inode = page->mapping->host;
  90         char *kaddr = page_address(page);
  91
  92         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  93                kaddr + offset, to - offset);
  94         mark_inode_dirty(inode);
  95         SetPageUptodate(page);
  96         kunmap(page);
  97         /* only one page here */
  98         if (to > inode->i_size)
  99                 inode->i_size = to;
 100         return 0;
 101 }
 102
 103 const struct address_space_operations udf_adinicb_aops = {
 104         .readpage       = udf_adinicb_readpage,
 105         .writepage      = udf_adinicb_writepage,
 106         .sync_page      = block_sync_page,
 107         .prepare_write  = udf_adinicb_prepare_write,
 108         .commit_write   = udf_adinicb_commit_write,
 109 };
 110
 111 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 112                                   unsigned long nr_segs, loff_t ppos)
 113 {
 114         ssize_t retval;
 115         struct file *file = iocb->ki_filp;
 116         struct inode *inode = file->f_path.dentry->d_inode;
 117         int err, pos;
 118         size_t count = iocb->ki_left;
 119
 120         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
 121                 if (file->f_flags & O_APPEND)
 122                         pos = inode->i_size;
 123                 else
 124                         pos = ppos;
 125
 126                 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
 127                                                 pos + count)) {
 128                         udf_expand_file_adinicb(inode, pos + count, &err);
 129                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) {
 130                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 131                                 return err;
 132                         }
 133                 } else {
 134                         if (pos + count > inode->i_size)
 135                                 UDF_I_LENALLOC(inode) = pos + count;
 136                         else
 137                                 UDF_I_LENALLOC(inode) = inode->i_size;
 138                 }
 139         }
 140
 141         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 142         if (retval > 0)
 143                 mark_inode_dirty(inode);
 144
 145         return retval;
 146 }
 147
 148 /*
 149  * udf_ioctl
 150  *
 151  * PURPOSE
 152  *      Issue an ioctl.
 153  *
 154  * DESCRIPTION
 155  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 156  *      available, and the ioctl cannot be handled without filesystem help.
 157  *
 158  *      sys_ioctl() handles these ioctls that apply only to regular files:
 159  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 160  *      These ioctls are also handled by sys_ioctl():
 161  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 162  *      All other ioctls are passed to the filesystem.
 163  *
 164  *      Refer to sys_ioctl() in fs/ioctl.c
 165  *      sys_ioctl() -> .
 166  *
 167  * PRE-CONDITIONS
 168  *      inode                   Pointer to inode that ioctl was issued on.
 169  *      filp                    Pointer to file that ioctl was issued on.
 170  *      cmd                     The ioctl command.
 171  *      arg                     The ioctl argument [can be interpreted as a
 172  *                              user-space pointer if desired].
 173  *
 174  * POST-CONDITIONS
 175  *      <return>                Success (>=0) or an error code (<=0) that
 176  *                              sys_ioctl() will return.
 177  *
 178  * HISTORY
 179  *      July 1, 1997 - Andrew E. Mileski
 180  *      Written, tested, and released.
 181  */
 182 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 183               unsigned long arg)
 184 {
 185         long old_block, new_block;
 186         int result = -EINVAL;
 187
 188         if (file_permission(filp, MAY_READ) != 0) {
 189                 udf_debug("no permission to access inode %lu\n",
 190                           inode->i_ino);
 191                 return -EPERM;
 192         }
 193
 194         if (!arg) {
 195                 udf_debug("invalid argument to udf_ioctl\n");
 196                 return -EINVAL;
 197         }
 198
 199         switch (cmd) {
 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                 if (!capable(CAP_SYS_ADMIN))
 205                         return -EACCES;
 206                 if (get_user(old_block, (long __user *)arg))
 207                         return -EFAULT;
 208                 if ((result = udf_relocate_blocks(inode->i_sb,
 209                                                   old_block, &new_block)) == 0)
 210                         result = put_user(new_block, (long __user *)arg);
 211                 return result;
 212         case UDF_GETEASIZE:
 213                 result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 214                 break;
 215         case UDF_GETEABLOCK:
 216                 result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 217                                       UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
 218                 break;
 219         }
 220
 221         return result;
 222 }
 223
 224 /*
 225  * udf_release_file
 226  *
 227  * PURPOSE
 228  *  Called when all references to the file are closed
 229  *
 230  * DESCRIPTION
 231  *  Discard prealloced blocks
 232  *
 233  * HISTORY
 234  *
 235  */
 236 static int udf_release_file(struct inode *inode, struct file *filp)
 237 {
 238         if (filp->f_mode & FMODE_WRITE) {
 239                 lock_kernel();
 240                 udf_discard_prealloc(inode);
 241                 unlock_kernel();
 242         }
 243         return 0;
 244 }
 245
 246 const struct file_operations udf_file_operations = {
 247         .read                   = do_sync_read,
 248         .aio_read               = generic_file_aio_read,
 249         .ioctl                  = udf_ioctl,
 250         .open                   = generic_file_open,
 251         .mmap                   = generic_file_mmap,
 252         .write                  = do_sync_write,
 253         .aio_write              = udf_file_aio_write,
 254         .release                = udf_release_file,
 255         .fsync                  = udf_fsync_file,
 256         .splice_read            = generic_file_splice_read,
 257 };
 258
 259 const struct inode_operations udf_file_inode_operations = {
 260         .truncate = udf_truncate,
 261 };