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 <asm/uaccess.h>
  31 #include <linux/kernel.h>
  32 #include <linux/string.h> /* memset */
  33 #include <linux/capability.h>
  34 #include <linux/errno.h>
  35 #include <linux/smp_lock.h>
  36 #include <linux/pagemap.h>
  37 #include <linux/buffer_head.h>
  38 #include <linux/aio.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         struct udf_inode_info *iinfo = UDF_I(inode);
  48
  49         BUG_ON(!PageLocked(page));
  50
  51         kaddr = kmap(page);
  52         memset(kaddr, 0, PAGE_CACHE_SIZE);
  53         memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, 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,
  63                                  struct writeback_control *wbc)
  64 {
  65         struct inode *inode = page->mapping->host;
  66         char *kaddr;
  67         struct udf_inode_info *iinfo = UDF_I(inode);
  68
  69         BUG_ON(!PageLocked(page));
  70
  71         kaddr = kmap(page);
  72         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  73         mark_inode_dirty(inode);
  74         SetPageUptodate(page);
  75         kunmap(page);
  76         unlock_page(page);
  77
  78         return 0;
  79 }
  80
  81 static int udf_adinicb_write_end(struct file *file,
  82                         struct address_space *mapping,
  83                         loff_t pos, unsigned len, unsigned copied,
  84                         struct page *page, void *fsdata)
  85 {
  86         struct inode *inode = mapping->host;
  87         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  88         char *kaddr;
  89         struct udf_inode_info *iinfo = UDF_I(inode);
  90
  91         kaddr = kmap_atomic(page, KM_USER0);
  92         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
  93                 kaddr + offset, copied);
  94         kunmap_atomic(kaddr, KM_USER0);
  95
  96         return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  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         .write_begin = simple_write_begin,
 104         .write_end = udf_adinicb_write_end,
 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         struct udf_inode_info *iinfo = UDF_I(inode);
 116
 117         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 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 <
 124                                 (udf_file_entry_alloc_offset(inode) +
 125                                                 pos + count)) {
 126                         udf_expand_file_adinicb(inode, pos + count, &err);
 127                         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 128                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 129                                 return err;
 130                         }
 131                 } else {
 132                         if (pos + count > inode->i_size)
 133                                 iinfo->i_lenAlloc = pos + count;
 134                         else
 135                                 iinfo->i_lenAlloc = inode->i_size;
 136                 }
 137         }
 138
 139         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 140         if (retval > 0)
 141                 mark_inode_dirty(inode);
 142
 143         return retval;
 144 }
 145
 146 int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 147               unsigned long arg)
 148 {
 149         long old_block, new_block;
 150         int result = -EINVAL;
 151
 152         if (file_permission(filp, MAY_READ) != 0) {
 153                 udf_debug("no permission to access inode %lu\n",
 154                           inode->i_ino);
 155                 return -EPERM;
 156         }
 157
 158         if (!arg) {
 159                 udf_debug("invalid argument to udf_ioctl\n");
 160                 return -EINVAL;
 161         }
 162
 163         switch (cmd) {
 164         case UDF_GETVOLIDENT:
 165                 if (copy_to_user((char __user *)arg,
 166                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
 167                         return -EFAULT;
 168                 else
 169                         return 0;
 170         case UDF_RELOCATE_BLOCKS:
 171                 if (!capable(CAP_SYS_ADMIN))
 172                         return -EACCES;
 173                 if (get_user(old_block, (long __user *)arg))
 174                         return -EFAULT;
 175                 result = udf_relocate_blocks(inode->i_sb,
 176                                                 old_block, &new_block);
 177                 if (result == 0)
 178                         result = put_user(new_block, (long __user *)arg);
 179                 return result;
 180         case UDF_GETEASIZE:
 181                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 182                 break;
 183         case UDF_GETEABLOCK:
 184                 result = copy_to_user((char __user *)arg,
 185                                       UDF_I(inode)->i_ext.i_data,
 186                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 187                 break;
 188         }
 189
 190         return result;
 191 }
 192
 193 static int udf_release_file(struct inode *inode, struct file *filp)
 194 {
 195         if (filp->f_mode & FMODE_WRITE) {
 196                 mutex_lock(&inode->i_mutex);
 197                 lock_kernel();
 198                 udf_discard_prealloc(inode);
 199                 unlock_kernel();
 200                 mutex_unlock(&inode->i_mutex);
 201         }
 202         return 0;
 203 }
 204
 205 const struct file_operations udf_file_operations = {
 206         .read                   = do_sync_read,
 207         .aio_read               = generic_file_aio_read,
 208         .ioctl                  = udf_ioctl,
 209         .open                   = generic_file_open,
 210         .mmap                   = generic_file_mmap,
 211         .write                  = do_sync_write,
 212         .aio_write              = udf_file_aio_write,
 213         .release                = udf_release_file,
 214         .fsync                  = simple_fsync,
 215         .splice_read            = generic_file_splice_read,
 216         .llseek                 = generic_file_llseek,
 217 };
 218
 219 const struct inode_operations udf_file_inode_operations = {
 220         .truncate = udf_truncate,
 221 };