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         return 0;
  59 }
  60
  61 static int udf_adinicb_writepage(struct page *page, struct writeback_control *wbc)
  62 {
  63         struct inode *inode = page->mapping->host;
  64         char *kaddr;
  65
  66         BUG_ON(!PageLocked(page));
  67
  68         kaddr = kmap(page);
  69         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode), kaddr, inode->i_size);
  70         mark_inode_dirty(inode);
  71         SetPageUptodate(page);
  72         kunmap(page);
  73         unlock_page(page);
  74         return 0;
  75 }
  76
  77 static int udf_adinicb_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  78 {
  79         kmap(page);
  80         return 0;
  81 }
  82
  83 static int udf_adinicb_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
  84 {
  85         struct inode *inode = page->mapping->host;
  86         char *kaddr = page_address(page);
  87
  88         memcpy(UDF_I_DATA(inode) + UDF_I_LENEATTR(inode) + offset,
  89                 kaddr + offset, to - offset);
  90         mark_inode_dirty(inode);
  91         SetPageUptodate(page);
  92         kunmap(page);
  93         /* only one page here */
  94         if (to > inode->i_size)
  95                 inode->i_size = to;
  96         return 0;
  97 }
  98
  99 const struct address_space_operations udf_adinicb_aops = {
 100         .readpage               = udf_adinicb_readpage,
 101         .writepage              = udf_adinicb_writepage,
 102         .sync_page              = block_sync_page,
 103         .prepare_write          = udf_adinicb_prepare_write,
 104         .commit_write           = udf_adinicb_commit_write,
 105 };
 106
 107 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 108                               unsigned long nr_segs, loff_t ppos)
 109 {
 110         ssize_t retval;
 111         struct file *file = iocb->ki_filp;
 112         struct inode *inode = file->f_path.dentry->d_inode;
 113         int err, pos;
 114         size_t count = iocb->ki_left;
 115
 116         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 117         {
 118                 if (file->f_flags & O_APPEND)
 119                         pos = inode->i_size;
 120                 else
 121                         pos = ppos;
 122
 123                 if (inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
 124                         pos + count))
 125                 {
 126                         udf_expand_file_adinicb(inode, pos + count, &err);
 127                         if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB)
 128                         {
 129                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 130                                 return err;
 131                         }
 132                 }
 133                 else
 134                 {
 135                         if (pos + count > inode->i_size)
 136                                 UDF_I_LENALLOC(inode) = pos + count;
 137                         else
 138                                 UDF_I_LENALLOC(inode) = inode->i_size;
 139                 }
 140         }
 141
 142         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 143
 144         if (retval > 0)
 145                 mark_inode_dirty(inode);
 146         return retval;
 147 }
 148
 149 /*
 150  * udf_ioctl
 151  *
 152  * PURPOSE
 153  *      Issue an ioctl.
 154  *
 155  * DESCRIPTION
 156  *      Optional - sys_ioctl() will return -ENOTTY if this routine is not
 157  *      available, and the ioctl cannot be handled without filesystem help.
 158  *
 159  *      sys_ioctl() handles these ioctls that apply only to regular files:
 160  *              FIBMAP [requires udf_block_map()], FIGETBSZ, FIONREAD
 161  *      These ioctls are also handled by sys_ioctl():
 162  *              FIOCLEX, FIONCLEX, FIONBIO, FIOASYNC
 163  *      All other ioctls are passed to the filesystem.
 164  *
 165  *      Refer to sys_ioctl() in fs/ioctl.c
 166  *      sys_ioctl() -> .
 167  *
 168  * PRE-CONDITIONS
 169  *      inode                   Pointer to inode that ioctl was issued on.
 170  *      filp                    Pointer to file that ioctl was issued on.
 171  *      cmd                     The ioctl command.
 172  *      arg                     The ioctl argument [can be interpreted as a
 173  *                              user-space pointer if desired].
 174  *
 175  * POST-CONDITIONS
 176  *      <return>                Success (>=0) or an error code (<=0) that
 177  *                              sys_ioctl() will return.
 178  *
 179  * HISTORY
 180  *      July 1, 1997 - Andrew E. Mileski
 181  *      Written, tested, and released.
 182  */
 183 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 184         unsigned long arg)
 185 {
 186         int result = -EINVAL;
 187
 188         if ( file_permission(filp, MAY_READ) != 0 )
 189         {
 190                 udf_debug("no permission to access inode %lu\n",
 191                                                 inode->i_ino);
 192                 return -EPERM;
 193         }
 194
 195         if ( !arg )
 196         {
 197                 udf_debug("invalid argument to udf_ioctl\n");
 198                 return -EINVAL;
 199         }
 200
 201         switch (cmd)
 202         {
 203                 case UDF_GETVOLIDENT:
 204                         return copy_to_user((char __user *)arg,
 205                                 UDF_SB_VOLIDENT(inode->i_sb), 32) ? -EFAULT : 0;
 206                 case UDF_RELOCATE_BLOCKS:
 207                 {
 208                         long old, new;
 209
 210                         if (!capable(CAP_SYS_ADMIN)) return -EACCES;
 211                         if (get_user(old, (long __user *)arg)) return -EFAULT;
 212                         if ((result = udf_relocate_blocks(inode->i_sb,
 213                                         old, &new)) == 0)
 214                                 result = put_user(new, (long __user *)arg);
 215
 216                         return result;
 217                 }
 218                 case UDF_GETEASIZE:
 219                         result = put_user(UDF_I_LENEATTR(inode), (int __user *)arg);
 220                         break;
 221
 222                 case UDF_GETEABLOCK:
 223                         result = copy_to_user((char __user *)arg, UDF_I_DATA(inode),
 224                                 UDF_I_LENEATTR(inode)) ? -EFAULT : 0;
 225                         break;
 226         }
 227
 228         return result;
 229 }
 230
 231 /*
 232  * udf_release_file
 233  *
 234  * PURPOSE
 235  *  Called when all references to the file are closed
 236  *
 237  * DESCRIPTION
 238  *  Discard prealloced blocks
 239  *
 240  * HISTORY
 241  *
 242  */
 243 static int udf_release_file(struct inode * inode, struct file * filp)
 244 {
 245         if (filp->f_mode & FMODE_WRITE)
 246         {
 247                 lock_kernel();
 248                 udf_discard_prealloc(inode);
 249                 unlock_kernel();
 250         }
 251         return 0;
 252 }
 253
 254 const struct file_operations udf_file_operations = {
 255         .read                   = do_sync_read,
 256         .aio_read               = generic_file_aio_read,
 257         .ioctl                  = udf_ioctl,
 258         .open                   = generic_file_open,
 259         .mmap                   = generic_file_mmap,
 260         .write                  = do_sync_write,
 261         .aio_write              = udf_file_aio_write,
 262         .release                = udf_release_file,
 263         .fsync                  = udf_fsync_file,
 264         .sendfile               = generic_file_sendfile,
 265 };
 266
 267 const struct inode_operations udf_file_inode_operations = {
 268         .truncate               = udf_truncate,
 269 };