mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-16 05:50:19 +00:00
fb89b45cdf
- Add cache=mmap option - Make mmap read-write while keeping it as synchronous as possible - Build writeback fid on mmap creation if it is writable Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
362 lines
8.4 KiB
C
362 lines
8.4 KiB
C
/*
|
|
* linux/fs/9p/vfs_addr.c
|
|
*
|
|
* This file contians vfs address (mmap) ops for 9P2000.
|
|
*
|
|
* Copyright (C) 2005 by Eric Van Hensbergen <ericvh@gmail.com>
|
|
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2
|
|
* as published by the Free Software Foundation.
|
|
*
|
|
* This program 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; if not, write to:
|
|
* Free Software Foundation
|
|
* 51 Franklin Street, Fifth Floor
|
|
* Boston, MA 02111-1301 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/file.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/string.h>
|
|
#include <linux/inet.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/idr.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/aio.h>
|
|
#include <net/9p/9p.h>
|
|
#include <net/9p/client.h>
|
|
|
|
#include "v9fs.h"
|
|
#include "v9fs_vfs.h"
|
|
#include "cache.h"
|
|
#include "fid.h"
|
|
|
|
/**
|
|
* v9fs_fid_readpage - read an entire page in from 9P
|
|
*
|
|
* @fid: fid being read
|
|
* @page: structure to page
|
|
*
|
|
*/
|
|
static int v9fs_fid_readpage(struct p9_fid *fid, struct page *page)
|
|
{
|
|
int retval;
|
|
loff_t offset;
|
|
char *buffer;
|
|
struct inode *inode;
|
|
|
|
inode = page->mapping->host;
|
|
p9_debug(P9_DEBUG_VFS, "\n");
|
|
|
|
BUG_ON(!PageLocked(page));
|
|
|
|
retval = v9fs_readpage_from_fscache(inode, page);
|
|
if (retval == 0)
|
|
return retval;
|
|
|
|
buffer = kmap(page);
|
|
offset = page_offset(page);
|
|
|
|
retval = v9fs_fid_readn(fid, buffer, NULL, PAGE_CACHE_SIZE, offset);
|
|
if (retval < 0) {
|
|
v9fs_uncache_page(inode, page);
|
|
goto done;
|
|
}
|
|
|
|
memset(buffer + retval, 0, PAGE_CACHE_SIZE - retval);
|
|
flush_dcache_page(page);
|
|
SetPageUptodate(page);
|
|
|
|
v9fs_readpage_to_fscache(inode, page);
|
|
retval = 0;
|
|
|
|
done:
|
|
kunmap(page);
|
|
unlock_page(page);
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* v9fs_vfs_readpage - read an entire page in from 9P
|
|
*
|
|
* @filp: file being read
|
|
* @page: structure to page
|
|
*
|
|
*/
|
|
|
|
static int v9fs_vfs_readpage(struct file *filp, struct page *page)
|
|
{
|
|
return v9fs_fid_readpage(filp->private_data, page);
|
|
}
|
|
|
|
/**
|
|
* v9fs_vfs_readpages - read a set of pages from 9P
|
|
*
|
|
* @filp: file being read
|
|
* @mapping: the address space
|
|
* @pages: list of pages to read
|
|
* @nr_pages: count of pages to read
|
|
*
|
|
*/
|
|
|
|
static int v9fs_vfs_readpages(struct file *filp, struct address_space *mapping,
|
|
struct list_head *pages, unsigned nr_pages)
|
|
{
|
|
int ret = 0;
|
|
struct inode *inode;
|
|
|
|
inode = mapping->host;
|
|
p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, filp);
|
|
|
|
ret = v9fs_readpages_from_fscache(inode, mapping, pages, &nr_pages);
|
|
if (ret == 0)
|
|
return ret;
|
|
|
|
ret = read_cache_pages(mapping, pages, (void *)v9fs_vfs_readpage, filp);
|
|
p9_debug(P9_DEBUG_VFS, " = %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* v9fs_release_page - release the private state associated with a page
|
|
*
|
|
* Returns 1 if the page can be released, false otherwise.
|
|
*/
|
|
|
|
static int v9fs_release_page(struct page *page, gfp_t gfp)
|
|
{
|
|
if (PagePrivate(page))
|
|
return 0;
|
|
return v9fs_fscache_release_page(page, gfp);
|
|
}
|
|
|
|
/**
|
|
* v9fs_invalidate_page - Invalidate a page completely or partially
|
|
*
|
|
* @page: structure to page
|
|
* @offset: offset in the page
|
|
*/
|
|
|
|
static void v9fs_invalidate_page(struct page *page, unsigned int offset,
|
|
unsigned int length)
|
|
{
|
|
/*
|
|
* If called with zero offset, we should release
|
|
* the private state assocated with the page
|
|
*/
|
|
if (offset == 0 && length == PAGE_CACHE_SIZE)
|
|
v9fs_fscache_invalidate_page(page);
|
|
}
|
|
|
|
static int v9fs_vfs_writepage_locked(struct page *page)
|
|
{
|
|
char *buffer;
|
|
int retval, len;
|
|
loff_t offset, size;
|
|
mm_segment_t old_fs;
|
|
struct v9fs_inode *v9inode;
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
v9inode = V9FS_I(inode);
|
|
size = i_size_read(inode);
|
|
if (page->index == size >> PAGE_CACHE_SHIFT)
|
|
len = size & ~PAGE_CACHE_MASK;
|
|
else
|
|
len = PAGE_CACHE_SIZE;
|
|
|
|
set_page_writeback(page);
|
|
|
|
buffer = kmap(page);
|
|
offset = page_offset(page);
|
|
|
|
old_fs = get_fs();
|
|
set_fs(get_ds());
|
|
/* We should have writeback_fid always set */
|
|
BUG_ON(!v9inode->writeback_fid);
|
|
|
|
retval = v9fs_file_write_internal(inode,
|
|
v9inode->writeback_fid,
|
|
(__force const char __user *)buffer,
|
|
len, &offset, 0);
|
|
if (retval > 0)
|
|
retval = 0;
|
|
|
|
set_fs(old_fs);
|
|
kunmap(page);
|
|
end_page_writeback(page);
|
|
return retval;
|
|
}
|
|
|
|
static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)
|
|
{
|
|
int retval;
|
|
|
|
p9_debug(P9_DEBUG_VFS, "page %p\n", page);
|
|
|
|
retval = v9fs_vfs_writepage_locked(page);
|
|
if (retval < 0) {
|
|
if (retval == -EAGAIN) {
|
|
redirty_page_for_writepage(wbc, page);
|
|
retval = 0;
|
|
} else {
|
|
SetPageError(page);
|
|
mapping_set_error(page->mapping, retval);
|
|
}
|
|
} else
|
|
retval = 0;
|
|
|
|
unlock_page(page);
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* v9fs_launder_page - Writeback a dirty page
|
|
* Returns 0 on success.
|
|
*/
|
|
|
|
static int v9fs_launder_page(struct page *page)
|
|
{
|
|
int retval;
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
v9fs_fscache_wait_on_page_write(inode, page);
|
|
if (clear_page_dirty_for_io(page)) {
|
|
retval = v9fs_vfs_writepage_locked(page);
|
|
if (retval)
|
|
return retval;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* v9fs_direct_IO - 9P address space operation for direct I/O
|
|
* @rw: direction (read or write)
|
|
* @iocb: target I/O control block
|
|
* @iov: array of vectors that define I/O buffer
|
|
* @pos: offset in file to begin the operation
|
|
* @nr_segs: size of iovec array
|
|
*
|
|
* The presence of v9fs_direct_IO() in the address space ops vector
|
|
* allowes open() O_DIRECT flags which would have failed otherwise.
|
|
*
|
|
* In the non-cached mode, we shunt off direct read and write requests before
|
|
* the VFS gets them, so this method should never be called.
|
|
*
|
|
* Direct IO is not 'yet' supported in the cached mode. Hence when
|
|
* this routine is called through generic_file_aio_read(), the read/write fails
|
|
* with an error.
|
|
*
|
|
*/
|
|
static ssize_t
|
|
v9fs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
|
|
loff_t pos, unsigned long nr_segs)
|
|
{
|
|
/*
|
|
* FIXME
|
|
* Now that we do caching with cache mode enabled, We need
|
|
* to support direct IO
|
|
*/
|
|
p9_debug(P9_DEBUG_VFS, "v9fs_direct_IO: v9fs_direct_IO (%s) off/no(%lld/%lu) EINVAL\n",
|
|
iocb->ki_filp->f_path.dentry->d_name.name,
|
|
(long long)pos, nr_segs);
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned flags,
|
|
struct page **pagep, void **fsdata)
|
|
{
|
|
int retval = 0;
|
|
struct page *page;
|
|
struct v9fs_inode *v9inode;
|
|
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
|
|
struct inode *inode = mapping->host;
|
|
|
|
|
|
p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
|
|
|
|
v9inode = V9FS_I(inode);
|
|
start:
|
|
page = grab_cache_page_write_begin(mapping, index, flags);
|
|
if (!page) {
|
|
retval = -ENOMEM;
|
|
goto out;
|
|
}
|
|
BUG_ON(!v9inode->writeback_fid);
|
|
if (PageUptodate(page))
|
|
goto out;
|
|
|
|
if (len == PAGE_CACHE_SIZE)
|
|
goto out;
|
|
|
|
retval = v9fs_fid_readpage(v9inode->writeback_fid, page);
|
|
page_cache_release(page);
|
|
if (!retval)
|
|
goto start;
|
|
out:
|
|
*pagep = page;
|
|
return retval;
|
|
}
|
|
|
|
static int v9fs_write_end(struct file *filp, struct address_space *mapping,
|
|
loff_t pos, unsigned len, unsigned copied,
|
|
struct page *page, void *fsdata)
|
|
{
|
|
loff_t last_pos = pos + copied;
|
|
struct inode *inode = page->mapping->host;
|
|
|
|
p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
|
|
|
|
if (unlikely(copied < len)) {
|
|
/*
|
|
* zero out the rest of the area
|
|
*/
|
|
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
|
|
|
|
zero_user(page, from + copied, len - copied);
|
|
flush_dcache_page(page);
|
|
}
|
|
|
|
if (!PageUptodate(page))
|
|
SetPageUptodate(page);
|
|
/*
|
|
* No need to use i_size_read() here, the i_size
|
|
* cannot change under us because we hold the i_mutex.
|
|
*/
|
|
if (last_pos > inode->i_size) {
|
|
inode_add_bytes(inode, last_pos - inode->i_size);
|
|
i_size_write(inode, last_pos);
|
|
}
|
|
set_page_dirty(page);
|
|
unlock_page(page);
|
|
page_cache_release(page);
|
|
|
|
return copied;
|
|
}
|
|
|
|
|
|
const struct address_space_operations v9fs_addr_operations = {
|
|
.readpage = v9fs_vfs_readpage,
|
|
.readpages = v9fs_vfs_readpages,
|
|
.set_page_dirty = __set_page_dirty_nobuffers,
|
|
.writepage = v9fs_vfs_writepage,
|
|
.write_begin = v9fs_write_begin,
|
|
.write_end = v9fs_write_end,
|
|
.releasepage = v9fs_release_page,
|
|
.invalidatepage = v9fs_invalidate_page,
|
|
.launder_page = v9fs_launder_page,
|
|
.direct_IO = v9fs_direct_IO,
|
|
};
|