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/quotaops.h>
  38 #include <linux/buffer_head.h>
  39 #include <linux/aio.h>
  40 #include <linux/smp_lock.h>
  41
  42 #include "udf_i.h"
  43 #include "udf_sb.h"
  44
  45 static int udf_adinicb_readpage(struct file *file, struct page *page)
  46 {
  47         struct inode *inode = page->mapping->host;
  48         char *kaddr;
  49         struct udf_inode_info *iinfo = UDF_I(inode);
  50
  51         BUG_ON(!PageLocked(page));
  52
  53         kaddr = kmap(page);
  54         memset(kaddr, 0, PAGE_CACHE_SIZE);
  55         memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
  56         flush_dcache_page(page);
  57         SetPageUptodate(page);
  58         kunmap(page);
  59         unlock_page(page);
  60
  61         return 0;
  62 }
  63
  64 static int udf_adinicb_writepage(struct page *page,
  65                                  struct writeback_control *wbc)
  66 {
  67         struct inode *inode = page->mapping->host;
  68         char *kaddr;
  69         struct udf_inode_info *iinfo = UDF_I(inode);
  70
  71         BUG_ON(!PageLocked(page));
  72
  73         kaddr = kmap(page);
  74         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size);
  75         mark_inode_dirty(inode);
  76         SetPageUptodate(page);
  77         kunmap(page);
  78         unlock_page(page);
  79
  80         return 0;
  81 }
  82
  83 static int udf_adinicb_write_end(struct file *file,
  84                         struct address_space *mapping,
  85                         loff_t pos, unsigned len, unsigned copied,
  86                         struct page *page, void *fsdata)
  87 {
  88         struct inode *inode = mapping->host;
  89         unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
  90         char *kaddr;
  91         struct udf_inode_info *iinfo = UDF_I(inode);
  92
  93         kaddr = kmap_atomic(page, KM_USER0);
  94         memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr + offset,
  95                 kaddr + offset, copied);
  96         kunmap_atomic(kaddr, KM_USER0);
  97
  98         return simple_write_end(file, mapping, pos, len, copied, page, fsdata);
  99 }
 100
 101 const struct address_space_operations udf_adinicb_aops = {
 102         .readpage       = udf_adinicb_readpage,
 103         .writepage      = udf_adinicb_writepage,
 104         .sync_page      = block_sync_page,
 105         .write_begin = simple_write_begin,
 106         .write_end = udf_adinicb_write_end,
 107 };
 108
 109 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 110                                   unsigned long nr_segs, loff_t ppos)
 111 {
 112         ssize_t retval;
 113         struct file *file = iocb->ki_filp;
 114         struct inode *inode = file->f_path.dentry->d_inode;
 115         int err, pos;
 116         size_t count = iocb->ki_left;
 117         struct udf_inode_info *iinfo = UDF_I(inode);
 118
 119         if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 120                 if (file->f_flags & O_APPEND)
 121                         pos = inode->i_size;
 122                 else
 123                         pos = ppos;
 124
 125                 if (inode->i_sb->s_blocksize <
 126                                 (udf_file_entry_alloc_offset(inode) +
 127                                                 pos + count)) {
 128                         udf_expand_file_adinicb(inode, pos + count, &err);
 129                         if (iinfo->i_alloc_type == 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                                 iinfo->i_lenAlloc = pos + count;
 136                         else
 137                                 iinfo->i_lenAlloc = 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 long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 149 {
 150         struct inode *inode = filp->f_dentry->d_inode;
 151         long old_block, new_block;
 152         int result = -EINVAL;
 153
 154         lock_kernel();
 155
 156         if (file_permission(filp, MAY_READ) != 0) {
 157                 udf_debug("no permission to access inode %lu\n", inode->i_ino);
 158                 result = -EPERM;
 159                 goto out;
 160         }
 161
 162         if (!arg) {
 163                 udf_debug("invalid argument to udf_ioctl\n");
 164                 result = -EINVAL;
 165                 goto out;
 166         }
 167
 168         switch (cmd) {
 169         case UDF_GETVOLIDENT:
 170                 if (copy_to_user((char __user *)arg,
 171                                  UDF_SB(inode->i_sb)->s_volume_ident, 32))
 172                         result = -EFAULT;
 173                 else
 174                         result = 0;
 175                 goto out;
 176         case UDF_RELOCATE_BLOCKS:
 177                 if (!capable(CAP_SYS_ADMIN)) {
 178                         result = -EACCES;
 179                         goto out;
 180                 }
 181                 if (get_user(old_block, (long __user *)arg)) {
 182                         result = -EFAULT;
 183                         goto out;
 184                 }
 185                 result = udf_relocate_blocks(inode->i_sb,
 186                                                 old_block, &new_block);
 187                 if (result == 0)
 188                         result = put_user(new_block, (long __user *)arg);
 189                 goto out;
 190         case UDF_GETEASIZE:
 191                 result = put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
 192                 goto out;
 193         case UDF_GETEABLOCK:
 194                 result = copy_to_user((char __user *)arg,
 195                                       UDF_I(inode)->i_ext.i_data,
 196                                       UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
 197                 goto out;
 198         }
 199
 200 out:
 201         unlock_kernel();
 202         return result;
 203 }
 204
 205 static int udf_release_file(struct inode *inode, struct file *filp)
 206 {
 207         if (filp->f_mode & FMODE_WRITE) {
 208                 mutex_lock(&inode->i_mutex);
 209                 lock_kernel();
 210                 udf_discard_prealloc(inode);
 211                 udf_truncate_tail_extent(inode);
 212                 unlock_kernel();
 213                 mutex_unlock(&inode->i_mutex);
 214         }
 215         return 0;
 216 }
 217
 218 const struct file_operations udf_file_operations = {
 219         .read                   = do_sync_read,
 220         .aio_read               = generic_file_aio_read,
 221         .unlocked_ioctl         = udf_ioctl,
 222         .open                   = dquot_file_open,
 223         .mmap                   = generic_file_mmap,
 224         .write                  = do_sync_write,
 225         .aio_write              = udf_file_aio_write,
 226         .release                = udf_release_file,
 227         .fsync                  = generic_file_fsync,
 228         .splice_read            = generic_file_splice_read,
 229         .llseek                 = generic_file_llseek,
 230 };
 231
 232 int udf_setattr(struct dentry *dentry, struct iattr *iattr)
 233 {
 234         struct inode *inode = dentry->d_inode;
 235         int error;
 236
 237         error = inode_change_ok(inode, iattr);
 238         if (error)
 239                 return error;
 240
 241         if (is_quota_modification(inode, iattr))
 242                 dquot_initialize(inode);
 243
 244         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
 245             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
 246                 error = dquot_transfer(inode, iattr);
 247                 if (error)
 248                         return error;
 249         }
 250
 251         return inode_setattr(inode, iattr);
 252 }
 253
 254 const struct inode_operations udf_file_inode_operations = {
 255         .truncate               = udf_truncate,
 256         .setattr                = udf_setattr,
 257 };