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./ocfs2/mmap.c:65: bebongs ==> belonging Signed-off-by: Keyur Patel <iamkeyur96@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Link: http://lkml.kernel.org/r/20200608014818.102358-1-iamkeyur96@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
180 lines
4.3 KiB
C
180 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* mmap.c
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*
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* Code to deal with the mess that is clustered mmap.
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*
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* Copyright (C) 2002, 2004 Oracle. All rights reserved.
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*/
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#include <linux/fs.h>
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#include <linux/types.h>
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#include <linux/highmem.h>
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#include <linux/pagemap.h>
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#include <linux/uio.h>
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#include <linux/signal.h>
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#include <linux/rbtree.h>
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#include <cluster/masklog.h>
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#include "ocfs2.h"
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#include "aops.h"
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#include "dlmglue.h"
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#include "file.h"
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#include "inode.h"
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#include "mmap.h"
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#include "super.h"
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#include "ocfs2_trace.h"
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static vm_fault_t ocfs2_fault(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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sigset_t oldset;
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vm_fault_t ret;
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ocfs2_block_signals(&oldset);
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ret = filemap_fault(vmf);
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ocfs2_unblock_signals(&oldset);
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trace_ocfs2_fault(OCFS2_I(vma->vm_file->f_mapping->host)->ip_blkno,
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vma, vmf->page, vmf->pgoff);
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return ret;
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}
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static vm_fault_t __ocfs2_page_mkwrite(struct file *file,
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struct buffer_head *di_bh, struct page *page)
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{
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int err;
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vm_fault_t ret = VM_FAULT_NOPAGE;
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struct inode *inode = file_inode(file);
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struct address_space *mapping = inode->i_mapping;
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loff_t pos = page_offset(page);
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unsigned int len = PAGE_SIZE;
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pgoff_t last_index;
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struct page *locked_page = NULL;
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void *fsdata;
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loff_t size = i_size_read(inode);
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last_index = (size - 1) >> PAGE_SHIFT;
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/*
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* There are cases that lead to the page no longer belonging to the
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* mapping.
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* 1) pagecache truncates locally due to memory pressure.
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* 2) pagecache truncates when another is taking EX lock against
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* inode lock. see ocfs2_data_convert_worker.
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*
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* The i_size check doesn't catch the case where nodes truncated and
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* then re-extended the file. We'll re-check the page mapping after
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* taking the page lock inside of ocfs2_write_begin_nolock().
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*
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* Let VM retry with these cases.
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*/
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if ((page->mapping != inode->i_mapping) ||
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(!PageUptodate(page)) ||
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(page_offset(page) >= size))
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goto out;
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/*
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* Call ocfs2_write_begin() and ocfs2_write_end() to take
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* advantage of the allocation code there. We pass a write
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* length of the whole page (chopped to i_size) to make sure
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* the whole thing is allocated.
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*
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* Since we know the page is up to date, we don't have to
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* worry about ocfs2_write_begin() skipping some buffer reads
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* because the "write" would invalidate their data.
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*/
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if (page->index == last_index)
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len = ((size - 1) & ~PAGE_MASK) + 1;
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err = ocfs2_write_begin_nolock(mapping, pos, len, OCFS2_WRITE_MMAP,
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&locked_page, &fsdata, di_bh, page);
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if (err) {
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if (err != -ENOSPC)
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mlog_errno(err);
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ret = vmf_error(err);
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goto out;
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}
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if (!locked_page) {
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ret = VM_FAULT_NOPAGE;
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goto out;
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}
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err = ocfs2_write_end_nolock(mapping, pos, len, len, fsdata);
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BUG_ON(err != len);
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ret = VM_FAULT_LOCKED;
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out:
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return ret;
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}
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static vm_fault_t ocfs2_page_mkwrite(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(vmf->vma->vm_file);
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struct buffer_head *di_bh = NULL;
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sigset_t oldset;
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int err;
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vm_fault_t ret;
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sb_start_pagefault(inode->i_sb);
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ocfs2_block_signals(&oldset);
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/*
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* The cluster locks taken will block a truncate from another
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* node. Taking the data lock will also ensure that we don't
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* attempt page truncation as part of a downconvert.
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*/
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err = ocfs2_inode_lock(inode, &di_bh, 1);
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if (err < 0) {
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mlog_errno(err);
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ret = vmf_error(err);
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goto out;
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}
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/*
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* The alloc sem should be enough to serialize with
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* ocfs2_truncate_file() changing i_size as well as any thread
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* modifying the inode btree.
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*/
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down_write(&OCFS2_I(inode)->ip_alloc_sem);
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ret = __ocfs2_page_mkwrite(vmf->vma->vm_file, di_bh, page);
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up_write(&OCFS2_I(inode)->ip_alloc_sem);
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brelse(di_bh);
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ocfs2_inode_unlock(inode, 1);
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out:
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ocfs2_unblock_signals(&oldset);
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sb_end_pagefault(inode->i_sb);
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return ret;
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}
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static const struct vm_operations_struct ocfs2_file_vm_ops = {
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.fault = ocfs2_fault,
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.page_mkwrite = ocfs2_page_mkwrite,
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};
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int ocfs2_mmap(struct file *file, struct vm_area_struct *vma)
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{
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int ret = 0, lock_level = 0;
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ret = ocfs2_inode_lock_atime(file_inode(file),
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file->f_path.mnt, &lock_level, 1);
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if (ret < 0) {
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mlog_errno(ret);
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goto out;
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}
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ocfs2_inode_unlock(file_inode(file), lock_level);
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out:
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vma->vm_ops = &ocfs2_file_vm_ops;
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return 0;
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}
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