Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964962Ab2JZPtu (ORCPT ); Fri, 26 Oct 2012 11:49:50 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:14856 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964822Ab2JZPtr (ORCPT ); Fri, 26 Oct 2012 11:49:47 -0400 Subject: [PATCH 03/12] fuse: rework fuse_retrieve() To: miklos@szeredi.hu From: Maxim Patlasov Cc: fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, devel@openvz.org Date: Fri, 26 Oct 2012 19:48:42 +0400 Message-ID: <20121026154835.18931.12676.stgit@maximpc.sw.ru> In-Reply-To: <20121026152957.18931.46330.stgit@maximpc.sw.ru> References: <20121026152957.18931.46330.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 Content-Length: 2118 Lines: 66 The patch reworks fuse_retrieve() to allocate only so many page pointers as needed. The core part of the patch is the following calculation: num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; (thanks Miklos for formula). All other changes are mostly shuffling lines. Signed-off-by: Maxim Patlasov --- fs/fuse/dev.c | 25 +++++++++++++++---------- 1 files changed, 15 insertions(+), 10 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index a5d4440..1266a5c 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1563,13 +1563,24 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, unsigned int num; unsigned int offset; size_t total_len = 0; + int num_pages; - req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); + offset = outarg->offset & ~PAGE_CACHE_MASK; + file_size = i_size_read(inode); + + num = outarg->size; + if (outarg->offset > file_size) + num = 0; + else if (outarg->offset + num > file_size) + num = file_size - outarg->offset; + + num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; + num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ); + + req = fuse_get_req(fc, num_pages); if (IS_ERR(req)) return PTR_ERR(req); - offset = outarg->offset & ~PAGE_CACHE_MASK; - req->in.h.opcode = FUSE_NOTIFY_REPLY; req->in.h.nodeid = outarg->nodeid; req->in.numargs = 2; @@ -1578,14 +1589,8 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, req->end = fuse_retrieve_end; index = outarg->offset >> PAGE_CACHE_SHIFT; - file_size = i_size_read(inode); - num = outarg->size; - if (outarg->offset > file_size) - num = 0; - else if (outarg->offset + num > file_size) - num = file_size - outarg->offset; - while (num && req->num_pages < FUSE_MAX_PAGES_PER_REQ) { + while (num && req->num_pages < num_pages) { struct page *page; unsigned int this_num; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/