161 lines
4.0 KiB
C
161 lines
4.0 KiB
C
/*
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* file.c - NILFS regular file handling primitives including fsync().
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*
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Written by Amagai Yoshiji and Ryusuke Konishi.
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*/
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/writeback.h>
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#include "nilfs.h"
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#include "segment.h"
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int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
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{
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/*
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* Called from fsync() system call
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* This is the only entry point that can catch write and synch
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* timing for both data blocks and intermediate blocks.
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*
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* This function should be implemented when the writeback function
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* will be implemented.
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*/
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struct the_nilfs *nilfs;
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struct inode *inode = file->f_mapping->host;
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int err = 0;
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if (nilfs_inode_dirty(inode)) {
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if (datasync)
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err = nilfs_construct_dsync_segment(inode->i_sb, inode,
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start, end);
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else
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err = nilfs_construct_segment(inode->i_sb);
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}
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nilfs = inode->i_sb->s_fs_info;
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if (!err)
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err = nilfs_flush_device(nilfs);
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return err;
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}
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static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
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{
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struct page *page = vmf->page;
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struct inode *inode = file_inode(vma->vm_file);
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struct nilfs_transaction_info ti;
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int ret = 0;
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if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
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return VM_FAULT_SIGBUS; /* -ENOSPC */
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sb_start_pagefault(inode->i_sb);
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lock_page(page);
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if (page->mapping != inode->i_mapping ||
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page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
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unlock_page(page);
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ret = -EFAULT; /* make the VM retry the fault */
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goto out;
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}
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/*
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* check to see if the page is mapped already (no holes)
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*/
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if (PageMappedToDisk(page))
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goto mapped;
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if (page_has_buffers(page)) {
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struct buffer_head *bh, *head;
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int fully_mapped = 1;
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bh = head = page_buffers(page);
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do {
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if (!buffer_mapped(bh)) {
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fully_mapped = 0;
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break;
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}
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} while (bh = bh->b_this_page, bh != head);
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if (fully_mapped) {
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SetPageMappedToDisk(page);
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goto mapped;
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}
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}
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unlock_page(page);
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/*
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* fill hole blocks
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*/
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ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
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/* never returns -ENOMEM, but may return -ENOSPC */
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if (unlikely(ret))
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goto out;
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file_update_time(vma->vm_file);
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ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
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if (ret) {
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nilfs_transaction_abort(inode->i_sb);
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goto out;
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}
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nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
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nilfs_transaction_commit(inode->i_sb);
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mapped:
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wait_for_stable_page(page);
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out:
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sb_end_pagefault(inode->i_sb);
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return block_page_mkwrite_return(ret);
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}
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static const struct vm_operations_struct nilfs_file_vm_ops = {
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.fault = filemap_fault,
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.map_pages = filemap_map_pages,
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.page_mkwrite = nilfs_page_mkwrite,
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};
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static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
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{
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file_accessed(file);
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vma->vm_ops = &nilfs_file_vm_ops;
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return 0;
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}
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/*
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* We have mostly NULL's here: the current defaults are ok for
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* the nilfs filesystem.
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*/
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const struct file_operations nilfs_file_operations = {
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.llseek = generic_file_llseek,
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.read_iter = generic_file_read_iter,
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.write_iter = generic_file_write_iter,
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.unlocked_ioctl = nilfs_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = nilfs_compat_ioctl,
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#endif /* CONFIG_COMPAT */
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.mmap = nilfs_file_mmap,
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.open = generic_file_open,
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/* .release = nilfs_release_file, */
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.fsync = nilfs_sync_file,
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.splice_read = generic_file_splice_read,
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};
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const struct inode_operations nilfs_file_inode_operations = {
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.setattr = nilfs_setattr,
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.permission = nilfs_permission,
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.fiemap = nilfs_fiemap,
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};
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/* end of file */
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