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/pagemap.h>
  36 #include <linux/buffer_head.h>
  37 #include <linux/aio.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         struct udf_inode_info *iinfo = UDF_I(inode);
  47
  48         BUG_ON(!PageLocked(page));
  49
  50         kaddr = kmap(page);
  51         memset(kaddr, 0, PAGE_CACHE_SIZE);
  52         memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
  53         flush_dcache_page(page);
  54         SetPageUptodate(page);
  55         kunmap(page);
  56         unlock_page(page);
  57
  58         return 0;
  59 }
  60
  61 static int udf_adinicb_writepage(struct page *page,
  62                                  struct writeback_control *wbc)
  63 {
  64         struct inode *inode = page->mapping->host;
  65         char *kaddr;
  66         struct udf_inode_info *iinfo = UDF_I(inode);
  67
  68         BUG_ON(!PageLocked(page));
  69
  70         kaddr = kmap(page);
  71         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  72         mark_inode_dirty(inode);
  73         SetPageUptodate(page);
  74         kunmap(page);
  75         unlock_page(page);
  76
  77         return 0;
  78 }
  79
  80 static int udf_adinicb_write_end(struct file *file,
  81                         struct address_space *mapping,
  82                         loff_t pos, unsigned len, unsigned copied,
  83                         struct page *page, void *fsdata)
  84 {
  85         struct inode *inode = mapping->host;
  86         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  87         char *kaddr;
  88         struct udf_inode_info *iinfo = UDF_I(inode);
  89
  90         kaddr = kmap_atomic(page, KM_USER0);
  91         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
  92                 kaddr + offset, copied);
  93         kunmap_atomic(kaddr, KM_USER0);
  94
  95         return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  96 }
  97
  98 const struct address_space_operations udf_adinicb_aops = {
  99         .readpage       = udf_adinicb_readpage,
 100         .writepage      = udf_adinicb_writepage,
 101         .write_begin = simple_write_begin,
 102         .write_end = udf_adinicb_write_end,
 103 };
 104
 105 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 106                                   unsigned long nr_segs, loff_t ppos)
 107 {
 108         ssize_t retval;
 109         struct file *file = iocb->ki_filp;
 110         struct inode *inode = file->f_path.dentry->d_inode;
 111         int err, pos;
 112         size_t count = iocb->ki_left;
 113         struct udf_inode_info *iinfo = UDF_I(inode);
 114
 115         down_write(&iinfo->i_data_sem);
 116         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 117                 if (file->f_flags & O_APPEND)
 118                         pos = inode->i_size;
 119                 else
 120                         pos = ppos;
 121
 122                 if (inode->i_sb->s_blocksize <
 123                                 (udf_file_entry_alloc_offset(inode) +
 124                                                 pos + count)) {
 125                         err = udf_expand_file_adinicb(inode);
 126                         if (err) {
 127                                 udf_debug("udf_expand_adinicb: err=%d\n", err);
 128                                 return err;
 129                         }
 130                 } else {
 131                         if (pos + count > inode->i_size)
 132                                 iinfo->i_lenAlloc = pos + count;
 133                         else
 134                                 iinfo->i_lenAlloc = inode->i_size;
 135                         up_write(&iinfo->i_data_sem);
 136                 }
 137         } else
 138                 up_write(&iinfo->i_data_sem);
 139
 140         retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
 141         if (retval > 0)
 142                 mark_inode_dirty(inode);
 143
 144         return retval;
 145 }
 146
 147 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 148 {
 149         struct inode *inode = filp->f_dentry->d_inode;
 150         long old_block, new_block;
 151         int result = -EINVAL;
 152
 153         if (inode_permission(inode, MAY_READ) != 0) {
 154                 udf_debug("no permission to access inode %lu\n", inode->i_ino);
 155                 result = -EPERM;
 156                 goto out;
 157         }
 158
 159         if (!arg) {
 160                 udf_debug("invalid argument to udf_ioctl\n");
 161                 result = -EINVAL;
 162                 goto out;
 163         }
 164
 165         switch (cmd) {
 166         case UDF_GETVOLIDENT:
 167                 if (copy_to_user((char __user *)arg,
 168                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
 169                         result = -EFAULT;
 170                 else
 171                         result = 0;
 172                 goto out;
 173         case UDF_RELOCATE_BLOCKS:
 174                 if (!capable(CAP_SYS_ADMIN)) {
 175                         result = -EACCES;
 176                         goto out;
 177                 }
 178                 if (get_user(old_block, (long __user *)arg)) {
 179                         result = -EFAULT;
 180                         goto out;
 181                 }
 182                 result = udf_relocate_blocks(inode->i_sb,
 183                                                 old_block, &new_block);
 184                 if (result == 0)
 185                         result = put_user(new_block, (long __user *)arg);
 186                 goto out;
 187         case UDF_GETEASIZE:
 188                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 189                 goto out;
 190         case UDF_GETEABLOCK:
 191                 result = copy_to_user((char __user *)arg,
 192                                       UDF_I(inode)->i_ext.i_data,
 193                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 194                 goto out;
 195         }
 196
 197 out:
 198         return result;
 199 }
 200
 201 static int udf_release_file(struct inode *inode, struct file *filp)
 202 {
 203         if (filp->f_mode & FMODE_WRITE) {
 204                 down_write(&UDF_I(inode)->i_data_sem);
 205                 udf_discard_prealloc(inode);
 206                 udf_truncate_tail_extent(inode);
 207                 up_write(&UDF_I(inode)->i_data_sem);
 208         }
 209         return 0;
 210 }
 211
 212 const struct file_operations udf_file_operations = {
 213         .read                   = do_sync_read,
 214         .aio_read               = generic_file_aio_read,
 215         .unlocked_ioctl         = udf_ioctl,
 216         .open                   = generic_file_open,
 217         .mmap                   = generic_file_mmap,
 218         .write                  = do_sync_write,
 219         .aio_write              = udf_file_aio_write,
 220         .release                = udf_release_file,
 221         .fsync                  = generic_file_fsync,
 222         .splice_read            = generic_file_splice_read,
 223         .llseek                 = generic_file_llseek,
 224 };
 225
 226 static int udf_setattr(struct dentry *dentry, struct iattr *attr)
 227 {
 228         struct inode *inode = dentry->d_inode;
 229         int error;
 230
 231         error = inode_change_ok(inode, attr);
 232         if (error)
 233                 return error;
 234
 235         if ((attr->ia_valid & ATTR_SIZE) &&
 236             attr->ia_size != i_size_read(inode)) {
 237                 error = udf_setsize(inode, attr->ia_size);
 238                 if (error)
 239                         return error;
 240         }
 241
 242         setattr_copy(inode, attr);
 243         mark_inode_dirty(inode);
 244         return 0;
 245 }
 246
 247 const struct inode_operations udf_file_inode_operations = {
 248         .setattr                = udf_setattr,
 249 };