From patchwork Thu Sep 16 08:40:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12498263 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A781C433EF for ; Thu, 16 Sep 2021 08:43:46 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9B4C661209 for ; Thu, 16 Sep 2021 08:43:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9B4C661209 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:43412 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mQmzg-0007Nq-Oo for qemu-devel@archiver.kernel.org; Thu, 16 Sep 2021 04:43:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48194) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQmxV-0004mm-Ug for qemu-devel@nongnu.org; Thu, 16 Sep 2021 04:41:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:37199) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQmxU-0004Mt-6a for qemu-devel@nongnu.org; Thu, 16 Sep 2021 04:41:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631781687; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=b8JCe2/MxdzLsWsSz1R0KzEI7jC387lZ5OvEsfnLoEs=; b=L+EPephdEbQpSLjPbU5zjoHhuMcRELB8AqOnkph1HRfo7c6l+GKArJbU8Pj+Ntr1PhGTBw rPPdmX1Jk5O4NEFSfWVdYdlVkn4R7+YthFzh1Bz8uXrSEh5xd9yy2TGSBCoLGUD/2V12Pv 2+XKZ8SxfkmFvEf3Rjy2/MYzBmBnqrU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-427-Erqfs7dPOSW7LPrOC0ZgmA-1; Thu, 16 Sep 2021 04:41:23 -0400 X-MC-Unique: Erqfs7dPOSW7LPrOC0ZgmA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3A6031006AA1 for ; Thu, 16 Sep 2021 08:41:22 +0000 (UTC) Received: from localhost (unknown [10.39.192.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AA3145B4BC; Thu, 16 Sep 2021 08:41:21 +0000 (UTC) From: Hanna Reitz To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v4 04/12] virtiofsd: Use lo_inode_open() instead of openat() Date: Thu, 16 Sep 2021 10:40:37 +0200 Message-Id: <20210916084045.31684-5-hreitz@redhat.com> In-Reply-To: <20210916084045.31684-1-hreitz@redhat.com> References: <20210916084045.31684-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.39, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Hanna Reitz , Stefan Hajnoczi , "Dr . David Alan Gilbert" , Vivek Goyal Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The xattr functions want a non-O_PATH FD, so they reopen the lo_inode.fd with the flags they need through /proc/self/fd. Similarly, lo_opendir() needs an O_RDONLY FD. Instead of the /proc/self/fd trick, it just uses openat(fd, "."), because the FD is guaranteed to be a directory, so this works. All cases have one problem in common, though: In the future, when we may have a file handle in the lo_inode instead of an FD, querying an lo_inode FD may incur an open_by_handle_at() call. It does not make sense to then reopen that FD with custom flags, those should have been passed to open_by_handle_at() instead. Use lo_inode_open() instead of openat(). As part of the file handle change, lo_inode_open() will be made to invoke openat() only if lo_inode.fd is valid. Otherwise, it will invoke open_by_handle_at() with the right flags from the start. Consequently, after this patch, lo_inode_open() is the only place to invoke openat() to reopen an existing FD with different flags. Signed-off-by: Hanna Reitz --- tools/virtiofsd/passthrough_ll.c | 47 ++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 17 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 88318a4ba9..d76283d080 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -1745,18 +1745,26 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino, { int error = ENOMEM; struct lo_data *lo = lo_data(req); - struct lo_dirp *d; + struct lo_inode *inode; + struct lo_dirp *d = NULL; int fd; ssize_t fh; + inode = lo_inode(req, ino); + if (!inode) { + error = EBADF; + goto out_err; + } + d = calloc(1, sizeof(struct lo_dirp)); if (d == NULL) { goto out_err; } - fd = openat(lo_fd(req, ino), ".", O_RDONLY); - if (fd == -1) { - goto out_errno; + fd = lo_inode_open(lo, inode, O_RDONLY); + if (fd < 0) { + error = -fd; + goto out_err; } d->dp = fdopendir(fd); @@ -1780,11 +1788,13 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino, fi->cache_readdir = 1; } fuse_reply_open(req, fi); + lo_inode_put(lo, &inode); return; out_errno: error = errno; out_err: + lo_inode_put(lo, &inode); if (d) { if (d->dp) { closedir(d->dp); @@ -2989,7 +2999,6 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, } } - sprintf(procname, "%i", inode->fd); /* * It is not safe to open() non-regular/non-dir files in file server * unless O_PATH is used, so use that method for regular files/dir @@ -2997,13 +3006,15 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, * Otherwise, call fchdir() to avoid open(). */ if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = openat(lo->proc_self_fd, procname, O_RDONLY); + fd = lo_inode_open(lo, inode, O_RDONLY); if (fd < 0) { - goto out_err; + saverr = -fd; + goto out; } ret = fgetxattr(fd, name, value, size); saverr = ret == -1 ? errno : 0; } else { + sprintf(procname, "%i", inode->fd); /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = getxattr(procname, name, value, size); @@ -3070,15 +3081,16 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) } } - sprintf(procname, "%i", inode->fd); if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = openat(lo->proc_self_fd, procname, O_RDONLY); + fd = lo_inode_open(lo, inode, O_RDONLY); if (fd < 0) { - goto out_err; + saverr = -fd; + goto out; } ret = flistxattr(fd, value, size); saverr = ret == -1 ? errno : 0; } else { + sprintf(procname, "%i", inode->fd); /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = listxattr(procname, value, size); @@ -3175,7 +3187,6 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, const char *value, size_t size, int flags, uint32_t extra_flags) { - char procname[64]; const char *name; char *mapped_name; struct lo_data *lo = lo_data(req); @@ -3221,16 +3232,15 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, fuse_log(FUSE_LOG_DEBUG, "lo_setxattr(ino=%" PRIu64 ", name=%s value=%s size=%zd)\n", ino, name, value, size); - sprintf(procname, "%i", inode->fd); /* * We can only open regular files or directories. If the inode is * something else, we have to enter /proc/self/fd and use * setxattr() on the link's filename there. */ if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = openat(lo->proc_self_fd, procname, O_RDONLY); + fd = lo_inode_open(lo, inode, O_RDONLY); if (fd < 0) { - saverr = errno; + saverr = -fd; goto out; } } else { @@ -3264,6 +3274,9 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, ret = fsetxattr(fd, name, value, size, flags); saverr = ret == -1 ? errno : 0; } else { + char procname[64]; + + sprintf(procname, "%i", inode->fd); ret = setxattr(procname, name, value, size, flags); saverr = ret == -1 ? errno : 0; } @@ -3333,16 +3346,16 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) fuse_log(FUSE_LOG_DEBUG, "lo_removexattr(ino=%" PRIu64 ", name=%s)\n", ino, name); - sprintf(procname, "%i", inode->fd); if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = openat(lo->proc_self_fd, procname, O_RDONLY); + fd = lo_inode_open(lo, inode, O_RDONLY); if (fd < 0) { - saverr = errno; + saverr = -fd; goto out; } ret = fremovexattr(fd, name); saverr = ret == -1 ? errno : 0; } else { + sprintf(procname, "%i", inode->fd); /* fchdir should not fail here */ FCHDIR_NOFAIL(lo->proc_self_fd); ret = removexattr(procname, name);