1 files changed, 290 insertions, 0 deletions
diff --git a/fs/udf/file.c b/fs/udf/file.c
new file mode 100644
index 000000000..e283a6270
--- /dev/null
+++ b/fs/udf/file.c
@@ -0,0 +1,290 @@
+/*
+ * file.c
+ *
+ * PURPOSE
+ *  File handling routines for the OSTA-UDF(tm) filesystem.
+ *
+ * COPYRIGHT
+ *  This file is distributed under the terms of the GNU General Public
+ *  License (GPL). Copies of the GPL can be obtained from:
+ *    ftp://prep.ai.mit.edu/pub/gnu/GPL
+ *  Each contributing author retains all rights to their own work.
+ *
+ *  (C) 1998-1999 Dave Boynton
+ *  (C) 1998-2004 Ben Fennema
+ *  (C) 1999-2000 Stelias Computing Inc
+ *
+ * HISTORY
+ *
+ *  10/02/98 dgb  Attempt to integrate into udf.o
+ *  10/07/98      Switched to using generic_readpage, etc., like isofs
+ *                And it works!
+ *  12/06/98 blf  Added udf_file_read. uses generic_file_read for all cases but
+ *                ICBTAG_FLAG_AD_IN_ICB.
+ *  04/06/99      64 bit file handling on 32 bit systems taken from ext2 file.c
+ *  05/12/99      Preliminary file write support
+ */
+
+#include "udfdecl.h"
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/string.h> /* memset */
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/pagemap.h>
+#include <linux/uio.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+static void __udf_adinicb_readpage(struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	char *kaddr;
+	struct udf_inode_info *iinfo = UDF_I(inode);
+	loff_t isize = i_size_read(inode);
+
+	/*
+	 * We have to be careful here as truncate can change i_size under us.
+	 * So just sample it once and use the same value everywhere.
+	 */
+	kaddr = kmap_atomic(page);
+	memcpy(kaddr, iinfo->i_data + iinfo->i_lenEAttr, isize);
+	memset(kaddr + isize, 0, PAGE_SIZE - isize);
+	flush_dcache_page(page);
+	SetPageUptodate(page);
+	kunmap_atomic(kaddr);
+}
+
+static int udf_adinicb_readpage(struct file *file, struct page *page)
+{
+	BUG_ON(!PageLocked(page));
+	__udf_adinicb_readpage(page);
+	unlock_page(page);
+
+	return 0;
+}
+
+static int udf_adinicb_writepage(struct page *page,
+				 struct writeback_control *wbc)
+{
+	struct inode *inode = page->mapping->host;
+	char *kaddr;
+	struct udf_inode_info *iinfo = UDF_I(inode);
+
+	BUG_ON(!PageLocked(page));
+
+	kaddr = kmap_atomic(page);
+	memcpy(iinfo->i_data + iinfo->i_lenEAttr, kaddr, i_size_read(inode));
+	SetPageUptodate(page);
+	kunmap_atomic(kaddr);
+	mark_inode_dirty(inode);
+	unlock_page(page);
+
+	return 0;
+}
+
+static int udf_adinicb_write_begin(struct file *file,
+			struct address_space *mapping, loff_t pos,
+			unsigned len, unsigned flags, struct page **pagep,
+			void **fsdata)
+{
+	struct page *page;
+
+	if (WARN_ON_ONCE(pos >= PAGE_SIZE))
+		return -EIO;
+	page = grab_cache_page_write_begin(mapping, 0, flags);
+	if (!page)
+		return -ENOMEM;
+	*pagep = page;
+
+	if (!PageUptodate(page))
+		__udf_adinicb_readpage(page);
+	return 0;
+}
+
+static ssize_t udf_adinicb_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+{
+	/* Fallback to buffered I/O. */
+	return 0;
+}
+
+static int udf_adinicb_write_end(struct file *file, struct address_space *mapping,
+				 loff_t pos, unsigned len, unsigned copied,
+				 struct page *page, void *fsdata)
+{
+	struct inode *inode = page->mapping->host;
+	loff_t last_pos = pos + copied;
+	if (last_pos > inode->i_size)
+		i_size_write(inode, last_pos);
+	set_page_dirty(page);
+	unlock_page(page);
+	put_page(page);
+	return copied;
+}
+
+const struct address_space_operations udf_adinicb_aops = {
+	.readpage	= udf_adinicb_readpage,
+	.writepage	= udf_adinicb_writepage,
+	.write_begin	= udf_adinicb_write_begin,
+	.write_end	= udf_adinicb_write_end,
+	.direct_IO	= udf_adinicb_direct_IO,
+};
+
+static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	ssize_t retval;
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file_inode(file);
+	struct udf_inode_info *iinfo = UDF_I(inode);
+	int err;
+
+	inode_lock(inode);
+
+	retval = generic_write_checks(iocb, from);
+	if (retval <= 0)
+		goto out;
+
+	down_write(&iinfo->i_data_sem);
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
+	    inode->i_sb->s_blocksize < (udf_file_entry_alloc_offset(inode) +
+				 iocb->ki_pos + iov_iter_count(from))) {
+		err = udf_expand_file_adinicb(inode);
+		if (err) {
+			inode_unlock(inode);
+			udf_debug("udf_expand_adinicb: err=%d\n", err);
+			return err;
+		}
+	} else
+		up_write(&iinfo->i_data_sem);
+
+	retval = __generic_file_write_iter(iocb, from);
+out:
+	down_write(&iinfo->i_data_sem);
+	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB && retval > 0)
+		iinfo->i_lenAlloc = inode->i_size;
+	up_write(&iinfo->i_data_sem);
+	inode_unlock(inode);
+
+	if (retval > 0) {
+		mark_inode_dirty(inode);
+		retval = generic_write_sync(iocb, retval);
+	}
+
+	return retval;
+}
+
+long udf_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	long old_block, new_block;
+	int result;
+
+	if (inode_permission(inode, MAY_READ) != 0) {
+		udf_debug("no permission to access inode %lu\n", inode->i_ino);
+		return -EPERM;
+	}
+
+	if (!arg && ((cmd == UDF_GETVOLIDENT) || (cmd == UDF_GETEASIZE) ||
+		     (cmd == UDF_RELOCATE_BLOCKS) || (cmd == UDF_GETEABLOCK))) {
+		udf_debug("invalid argument to udf_ioctl\n");
+		return -EINVAL;
+	}
+
+	switch (cmd) {
+	case UDF_GETVOLIDENT:
+		if (copy_to_user((char __user *)arg,
+				 UDF_SB(inode->i_sb)->s_volume_ident, 32))
+			return -EFAULT;
+		return 0;
+	case UDF_RELOCATE_BLOCKS:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+		if (get_user(old_block, (long __user *)arg))
+			return -EFAULT;
+		result = udf_relocate_blocks(inode->i_sb,
+						old_block, &new_block);
+		if (result == 0)
+			result = put_user(new_block, (long __user *)arg);
+		return result;
+	case UDF_GETEASIZE:
+		return put_user(UDF_I(inode)->i_lenEAttr, (int __user *)arg);
+	case UDF_GETEABLOCK:
+		return copy_to_user((char __user *)arg,
+				    UDF_I(inode)->i_data,
+				    UDF_I(inode)->i_lenEAttr) ? -EFAULT : 0;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	return 0;
+}
+
+static int udf_release_file(struct inode *inode, struct file *filp)
+{
+	if (filp->f_mode & FMODE_WRITE &&
+	    atomic_read(&inode->i_writecount) == 1) {
+		/*
+		 * Grab i_mutex to avoid races with writes changing i_size
+		 * while we are running.
+		 */
+		inode_lock(inode);
+		down_write(&UDF_I(inode)->i_data_sem);
+		udf_discard_prealloc(inode);
+		udf_truncate_tail_extent(inode);
+		up_write(&UDF_I(inode)->i_data_sem);
+		inode_unlock(inode);
+	}
+	return 0;
+}
+
+const struct file_operations udf_file_operations = {
+	.read_iter		= generic_file_read_iter,
+	.unlocked_ioctl		= udf_ioctl,
+	.open			= generic_file_open,
+	.mmap			= generic_file_mmap,
+	.write_iter		= udf_file_write_iter,
+	.release		= udf_release_file,
+	.fsync			= generic_file_fsync,
+	.splice_read		= generic_file_splice_read,
+	.llseek			= generic_file_llseek,
+};
+
+static int udf_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	struct inode *inode = d_inode(dentry);
+	struct super_block *sb = inode->i_sb;
+	int error;
+
+	error = setattr_prepare(dentry, attr);
+	if (error)
+		return error;
+
+	if ((attr->ia_valid & ATTR_UID) &&
+	    UDF_QUERY_FLAG(sb, UDF_FLAG_UID_SET) &&
+	    !uid_eq(attr->ia_uid, UDF_SB(sb)->s_uid))
+		return -EPERM;
+	if ((attr->ia_valid & ATTR_GID) &&
+	    UDF_QUERY_FLAG(sb, UDF_FLAG_GID_SET) &&
+	    !gid_eq(attr->ia_gid, UDF_SB(sb)->s_gid))
+		return -EPERM;
+
+	if ((attr->ia_valid & ATTR_SIZE) &&
+	    attr->ia_size != i_size_read(inode)) {
+		error = udf_setsize(inode, attr->ia_size);
+		if (error)
+			return error;
+	}
+
+	if (attr->ia_valid & ATTR_MODE)
+		udf_update_extra_perms(inode, attr->ia_mode);
+
+	setattr_copy(inode, attr);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+const struct inode_operations udf_file_inode_operations = {
+	.setattr		= udf_setattr,
+};