/* * file.c - NTFS kernel file operations. Part of the Linux-NTFS project. * * Copyright (c) 2001-2005 Anton Altaparmakov * * This program/include file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program/include file is distributed in the hope that it will be * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (in the main directory of the Linux-NTFS * distribution in the file COPYING); if not, write to the Free Software * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/pagemap.h> #include <linux/buffer_head.h> #include "inode.h" #include "debug.h" #include "ntfs.h" /** * ntfs_file_open - called when an inode is about to be opened * @vi: inode to be opened * @filp: file structure describing the inode * * Limit file size to the page cache limit on architectures where unsigned long * is 32-bits. This is the most we can do for now without overflowing the page * cache page index. Doing it this way means we don't run into problems because * of existing too large files. It would be better to allow the user to read * the beginning of the file but I doubt very much anyone is going to hit this * check on a 32-bit architecture, so there is no point in adding the extra * complexity required to support this. * * On 64-bit architectures, the check is hopefully optimized away by the * compiler. * * After the check passes, just call generic_file_open() to do its work. */ static int ntfs_file_open(struct inode *vi, struct file *filp) { if (sizeof(unsigned long) < 8) { if (i_size_read(vi) > MAX_LFS_FILESIZE) return -EFBIG; } return generic_file_open(vi, filp); } #ifdef NTFS_RW /** * ntfs_file_fsync - sync a file to disk * @filp: file to be synced * @dentry: dentry describing the file to sync * @datasync: if non-zero only flush user data and not metadata * * Data integrity sync of a file to disk. Used for fsync, fdatasync, and msync * system calls. This function is inspired by fs/buffer.c::file_fsync(). * * If @datasync is false, write the mft record and all associated extent mft * records as well as the $DATA attribute and then sync the block device. * * If @datasync is true and the attribute is non-resident, we skip the writing * of the mft record and all associated extent mft records (this might still * happen due to the write_inode_now() call). * * Also, if @datasync is true, we do not wait on the inode to be written out * but we always wait on the page cache pages to be written out. * * Note: In the past @filp could be NULL so we ignore it as we don't need it * anyway. * * Locking: Caller must hold i_sem on the inode. * * TODO: We should probably also write all attribute/index inodes associated * with this inode but since we have no simple way of getting to them we ignore * this problem for now. */ static int ntfs_file_fsync(struct file *filp, struct dentry *dentry, int datasync) { struct inode *vi = dentry->d_inode; int err, ret = 0; ntfs_debug("Entering for inode 0x%lx.", vi->i_ino); BUG_ON(S_ISDIR(vi->i_mode)); if (!datasync || !NInoNonResident(NTFS_I(vi))) ret = ntfs_write_inode(vi, 1); write_inode_now(vi, !datasync); /* * NOTE: If we were to use mapping->private_list (see ext2 and * fs/buffer.c) for dirty blocks then we could optimize the below to be * sync_mapping_buffers(vi->i_mapping). */ err = sync_blockdev(vi->i_sb->s_bdev); if (unlikely(err && !ret)) ret = err; if (likely(!ret)) ntfs_debug("Done."); else ntfs_warning(vi->i_sb, "Failed to f%ssync inode 0x%lx. Error " "%u.", datasync ? "data" : "", vi->i_ino, -ret); return ret; } #endif /* NTFS_RW */ struct file_operations ntfs_file_ops = { .llseek = generic_file_llseek, /* Seek inside file. */ .read = generic_file_read, /* Read from file. */ .aio_read = generic_file_aio_read, /* Async read from file. */ .readv = generic_file_readv, /* Read from file. */ #ifdef NTFS_RW .write = generic_file_write, /* Write to file. */ .aio_write = generic_file_aio_write, /* Async write to file. */ .writev = generic_file_writev, /* Write to file. */ /*.release = ,*/ /* Last file is closed. See fs/ext2/file.c:: ext2_release_file() for how to use this to discard preallocated space for write opened files. */ .fsync = ntfs_file_fsync, /* Sync a file to disk. */ /*.aio_fsync = ,*/ /* Sync all outstanding async i/o operations on a kiocb. */ #endif /* NTFS_RW */ /*.ioctl = ,*/ /* Perform function on the mounted filesystem. */ .mmap = generic_file_mmap, /* Mmap file. */ .open = ntfs_file_open, /* Open file. */ .sendfile = generic_file_sendfile, /* Zero-copy data send with the data source being on the ntfs partition. We do not need to care about the data destination. */ /*.sendpage = ,*/ /* Zero-copy data send with the data destination being on the ntfs partition. We do not need to care about the data source. */ }; struct inode_operations ntfs_file_inode_ops = { #ifdef NTFS_RW .truncate = ntfs_truncate_vfs, .setattr = ntfs_setattr, #endif /* NTFS_RW */ }; struct file_operations ntfs_empty_file_ops = {}; struct inode_operations ntfs_empty_inode_ops = {};