From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831Ab2KPRIC (ORCPT ); Fri, 16 Nov 2012 12:08:02 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:30800 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752446Ab2KPRIA (ORCPT ); Fri, 16 Nov 2012 12:08:00 -0500 Subject: [PATCH 06/14] fuse: Trust kernel i_size only To: miklos@szeredi.hu From: Maxim Patlasov Cc: dev@parallels.com, fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, jbottomley@parallels.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, xemul@openvz.org Date: Fri, 16 Nov 2012 21:07:46 +0400 Message-ID: <20121116170731.3196.47157.stgit@maximpc.sw.ru> In-Reply-To: <20121116170123.3196.93431.stgit@maximpc.sw.ru> References: <20121116170123.3196.93431.stgit@maximpc.sw.ru> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make fuse think that when writeback is on the inode's i_size is always up-to-date and not update it with the value received from the userspace. This is done because the page cache code may update i_size without letting the FS know. This assumption implies fixing the previously introduced short-read helper -- when a short read occurs the 'hole' is filled with zeroes. fuse_file_fallocate() is also fixed because now we should keep i_size up to date, so it must be updated if FUSE_FALLOCATE request succeeded. Original patch by: Pavel Emelyanov Signed-off-by: Maxim Patlasov --- fs/fuse/dir.c | 9 ++++++--- fs/fuse/file.c | 39 +++++++++++++++++++++++++++++++++++++-- fs/fuse/inode.c | 6 ++++-- 3 files changed, 47 insertions(+), 7 deletions(-) diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 324bc08..3e7250e 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -827,7 +827,7 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr, stat->mtime.tv_nsec = attr->mtimensec; stat->ctime.tv_sec = attr->ctime; stat->ctime.tv_nsec = attr->ctimensec; - stat->size = attr->size; + stat->size = i_size_read(inode); stat->blocks = attr->blocks; if (attr->blksize != 0) @@ -1388,6 +1388,7 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, struct fuse_setattr_in inarg; struct fuse_attr_out outarg; bool is_truncate = false; + bool is_wb = fc->writeback_cache; loff_t oldsize; int err; @@ -1460,7 +1461,8 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, fuse_change_attributes_common(inode, &outarg.attr, attr_timeout(&outarg)); oldsize = inode->i_size; - i_size_write(inode, outarg.attr.size); + if (!is_wb || is_truncate || !S_ISREG(inode->i_mode)) + i_size_write(inode, outarg.attr.size); if (is_truncate) { /* NOTE: this may release/reacquire fc->lock */ @@ -1472,7 +1474,8 @@ static int fuse_do_setattr(struct dentry *entry, struct iattr *attr, * Only call invalidate_inode_pages2() after removing * FUSE_NOWRITE, otherwise fuse_launder_page() would deadlock. */ - if (S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { + if ((is_truncate || !is_wb) && + S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) { truncate_pagecache(inode, oldsize, outarg.attr.size); invalidate_inode_pages2(inode->i_mapping); } diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 0cc62f59..d13d57b 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -543,9 +543,29 @@ static void fuse_short_read(struct fuse_req *req, struct inode *inode, u64 attr_ver) { size_t num_read = req->out.args[0].size; + struct fuse_conn *fc = get_fuse_conn(inode); + + if (fc->writeback_cache) { + /* + * A hole in a file. Some data after the hole are in page cache. + */ + int i; + int start_idx = num_read >> PAGE_CACHE_SHIFT; + size_t off = num_read & (PAGE_CACHE_SIZE - 1); - loff_t pos = page_offset(req->pages[0]) + num_read; - fuse_read_update_size(inode, pos, attr_ver); + for (i = start_idx; i < req->num_pages; i++) { + struct page *page = req->pages[i]; + void *mapaddr = kmap_atomic(page); + + memset(mapaddr + off, 0, PAGE_CACHE_SIZE - off); + + kunmap_atomic(mapaddr); + off = 0; + } + } else { + loff_t pos = page_offset(req->pages[0]) + num_read; + fuse_read_update_size(inode, pos, attr_ver); + } } static int fuse_readpage(struct file *file, struct page *page) @@ -2216,6 +2236,7 @@ long fuse_file_fallocate(struct file *file, int mode, loff_t offset, .mode = mode }; int err; + bool is_wb = fc->writeback_cache; if (fc->no_fallocate) return -EOPNOTSUPP; @@ -2224,6 +2245,11 @@ long fuse_file_fallocate(struct file *file, int mode, loff_t offset, if (IS_ERR(req)) return PTR_ERR(req); + if (is_wb) { + struct inode *inode = file->f_mapping->host; + mutex_lock(&inode->i_mutex); + } + req->in.h.opcode = FUSE_FALLOCATE; req->in.h.nodeid = ff->nodeid; req->in.numargs = 1; @@ -2237,6 +2263,15 @@ long fuse_file_fallocate(struct file *file, int mode, loff_t offset, } fuse_put_request(fc, req); + if (is_wb) { + struct inode *inode = file->f_mapping->host; + + if (!err) + fuse_write_update_size(inode, offset + length); + + mutex_unlock(&inode->i_mutex); + } + return err; } EXPORT_SYMBOL_GPL(fuse_file_fallocate); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index f0eda12..b2d1a27 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -196,6 +196,7 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, { struct fuse_conn *fc = get_fuse_conn(inode); struct fuse_inode *fi = get_fuse_inode(inode); + bool is_wb = fc->writeback_cache; loff_t oldsize; struct timespec old_mtime; @@ -209,10 +210,11 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, fuse_change_attributes_common(inode, attr, attr_valid); oldsize = inode->i_size; - i_size_write(inode, attr->size); + if (!is_wb || !S_ISREG(inode->i_mode)) + i_size_write(inode, attr->size); spin_unlock(&fc->lock); - if (S_ISREG(inode->i_mode)) { + if (!is_wb && S_ISREG(inode->i_mode)) { bool inval = false; if (oldsize != attr->size) {