/* * 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 <net/9p/9p.h> #include <net/9p/client.h> #include "v9fs.h" #include "v9fs_vfs.h" #include "cache.h" /** * 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) { int retval; loff_t offset; char *buffer; struct inode *inode; inode = page->mapping->host; P9_DPRINTK(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_file_readn(filp, 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_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_DPRINTK(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_DPRINTK(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 long offset) { if (offset == 0) v9fs_fscache_invalidate_page(page); } /** * v9fs_launder_page - Writeback a dirty page * Since the writes go directly to the server, we simply return a 0 * here to indicate success. * * Returns 0 on success. */ static int v9fs_launder_page(struct page *page) { return 0; } const struct address_space_operations v9fs_addr_operations = { .readpage = v9fs_vfs_readpage, .readpages = v9fs_vfs_readpages, .releasepage = v9fs_release_page, .invalidatepage = v9fs_invalidate_page, .launder_page = v9fs_launder_page, };