From patchwork Fri Jul 30 15:01:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 12411537 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 DAA26C4338F for ; Fri, 30 Jul 2021 15:11:30 +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 38F2160F94 for ; Fri, 30 Jul 2021 15:11:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 38F2160F94 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]:48670 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m9UAb-00063i-BJ for qemu-devel@archiver.kernel.org; Fri, 30 Jul 2021 11:11:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49290) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m9U2N-0006DN-Qj for qemu-devel@nongnu.org; Fri, 30 Jul 2021 11:02:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55048) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m9U2L-0007x4-Hh for qemu-devel@nongnu.org; Fri, 30 Jul 2021 11:02:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627657377; 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=zj6FlfRk0Y1iH5pn3wm7uFE+2a56sGUjaPe4skrCOY8=; b=Sjv0I4INhrSMgN8vZ7z/h5OFMJZc7KCIBPNJJJww2K8aGqtH1OwVLwB9XPhSdJARBAqwgJ k0HR/ADSkBP/ZiwfRwAj0XdIiUOW/nowuhIT2jYyGrNvh8J9xbkwt6/Nep61ee5WPrnV46 lluH/ctzwyDK+rhN3VHNoEQK7KEtyQA= 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-285-R8SrVj77NBeaBDyrMtrILw-1; Fri, 30 Jul 2021 11:02:55 -0400 X-MC-Unique: R8SrVj77NBeaBDyrMtrILw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DF3188914F8 for ; Fri, 30 Jul 2021 15:02:29 +0000 (UTC) Received: from localhost (unknown [10.39.193.62]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6EC4710074FD; Fri, 30 Jul 2021 15:02:20 +0000 (UTC) From: Max Reitz To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v3 06/10] virtiofsd: Let lo_inode_open() return a TempFd Date: Fri, 30 Jul 2021 17:01:30 +0200 Message-Id: <20210730150134.216126-7-mreitz@redhat.com> In-Reply-To: <20210730150134.216126-1-mreitz@redhat.com> References: <20210730150134.216126-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.717, 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_H3=0.001, RCVD_IN_MSPIKE_WL=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: Stefan Hajnoczi , "Dr . David Alan Gilbert" , Vivek Goyal , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Strictly speaking, this is not necessary, because lo_inode_open() will always return a new FD owned by the caller, so TempFd.owned will always be true. However, auto-cleanup is nice, and in some cases this plays nicely with an lo_inode_fd() call in another conditional branch (see lo_setattr()). Signed-off-by: Max Reitz --- tools/virtiofsd/passthrough_ll.c | 138 +++++++++++++------------------ 1 file changed, 59 insertions(+), 79 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 9e1bc37af8..292b7f7e27 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -291,10 +291,8 @@ static void temp_fd_clear(TempFd *temp_fd) /** * Return an owned fd from *temp_fd that will not be closed when * *temp_fd goes out of scope. - * - * (TODO: Remove __attribute__ once this is used.) */ -static __attribute__((unused)) int temp_fd_steal(TempFd *temp_fd) +static int temp_fd_steal(TempFd *temp_fd) { if (temp_fd->owned) { temp_fd->owned = false; @@ -673,9 +671,12 @@ static int lo_fd(fuse_req_t req, fuse_ino_t ino, TempFd *tfd) * when a malicious client opens special files such as block device nodes. * Symlink inodes are also rejected since symlinks must already have been * traversed on the client side. + * + * The fd is returned in tfd->fd. The return value is 0 on success and -errno + * otherwise. */ -static int lo_inode_open(struct lo_data *lo, struct lo_inode *inode, - int open_flags) +static int lo_inode_open(const struct lo_data *lo, const struct lo_inode *inode, + int open_flags, TempFd *tfd) { g_autofree char *fd_str = g_strdup_printf("%d", inode->fd); int fd; @@ -694,7 +695,13 @@ static int lo_inode_open(struct lo_data *lo, struct lo_inode *inode, if (fd < 0) { return -errno; } - return fd; + + *tfd = (TempFd) { + .fd = fd, + .owned = true, + }; + + return 0; } static void lo_init(void *userdata, struct fuse_conn_info *conn) @@ -852,7 +859,12 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, return; } - res = lo_inode_fd(inode, &inode_fd); + if (!fi && (valid & FUSE_SET_ATTR_SIZE)) { + /* We need an O_RDWR FD for ftruncate() */ + res = lo_inode_open(lo, inode, O_RDWR, &inode_fd); + } else { + res = lo_inode_fd(inode, &inode_fd); + } if (res < 0) { saverr = -res; goto out_err; @@ -900,18 +912,11 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, if (fi) { truncfd = fd; } else { - truncfd = lo_inode_open(lo, inode, O_RDWR); - if (truncfd < 0) { - saverr = -truncfd; - goto out_err; - } + truncfd = inode_fd.fd; } saverr = drop_security_capability(lo, truncfd); if (saverr) { - if (!fi) { - close(truncfd); - } goto out_err; } @@ -919,9 +924,6 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, res = drop_effective_cap("FSETID", &cap_fsetid_dropped); if (res != 0) { saverr = res; - if (!fi) { - close(truncfd); - } goto out_err; } } @@ -934,9 +936,6 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, fuse_log(FUSE_LOG_ERR, "Failed to gain CAP_FSETID\n"); } } - if (!fi) { - close(truncfd); - } if (res == -1) { goto out_err; } @@ -1822,11 +1821,12 @@ static struct lo_dirp *lo_dirp(fuse_req_t req, struct fuse_file_info *fi) static void lo_opendir(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) { + g_auto(TempFd) inode_fd = TEMP_FD_INIT; int error = ENOMEM; struct lo_data *lo = lo_data(req); struct lo_inode *inode; struct lo_dirp *d = NULL; - int fd; + int res; ssize_t fh; inode = lo_inode(req, ino); @@ -1840,13 +1840,13 @@ static void lo_opendir(fuse_req_t req, fuse_ino_t ino, goto out_err; } - fd = lo_inode_open(lo, inode, O_RDONLY); - if (fd < 0) { - error = -fd; + res = lo_inode_open(lo, inode, O_RDONLY, &inode_fd); + if (res < 0) { + error = -res; goto out_err; } - d->dp = fdopendir(fd); + d->dp = fdopendir(temp_fd_steal(&inode_fd)); if (d->dp == NULL) { goto out_errno; } @@ -1876,8 +1876,6 @@ out_err: if (d) { if (d->dp) { closedir(d->dp); - } else if (fd != -1) { - close(fd); } free(d); } @@ -2077,6 +2075,7 @@ static void update_open_flags(int writeback, int allow_direct_io, static int lo_do_open(struct lo_data *lo, struct lo_inode *inode, int existing_fd, struct fuse_file_info *fi) { + g_auto(TempFd) inode_fd = TEMP_FD_INIT; ssize_t fh; int fd = existing_fd; int err; @@ -2093,16 +2092,18 @@ static int lo_do_open(struct lo_data *lo, struct lo_inode *inode, } } - fd = lo_inode_open(lo, inode, fi->flags); + err = lo_inode_open(lo, inode, fi->flags, &inode_fd); if (cap_fsetid_dropped) { if (gain_effective_cap("FSETID")) { fuse_log(FUSE_LOG_ERR, "Failed to gain CAP_FSETID\n"); } } - if (fd < 0) { - return -fd; + if (err < 0) { + return -err; } + fd = temp_fd_steal(&inode_fd); + if (fi->flags & (O_TRUNC)) { int err = drop_security_capability(lo, fd); if (err) { @@ -2212,8 +2213,9 @@ static struct lo_inode_plock *lookup_create_plock_ctx(struct lo_data *lo, uint64_t lock_owner, pid_t pid, int *err) { + g_auto(TempFd) inode_fd = TEMP_FD_INIT; struct lo_inode_plock *plock; - int fd; + int res; plock = g_hash_table_lookup(inode->posix_locks, GUINT_TO_POINTER(lock_owner)); @@ -2230,15 +2232,15 @@ static struct lo_inode_plock *lookup_create_plock_ctx(struct lo_data *lo, /* Open another instance of file which can be used for ofd locks. */ /* TODO: What if file is not writable? */ - fd = lo_inode_open(lo, inode, O_RDWR); - if (fd < 0) { - *err = -fd; + res = lo_inode_open(lo, inode, O_RDWR, &inode_fd); + if (res < 0) { + *err = -res; free(plock); return NULL; } plock->lock_owner = lock_owner; - plock->fd = fd; + plock->fd = temp_fd_steal(&inode_fd); g_hash_table_insert(inode->posix_locks, GUINT_TO_POINTER(plock->lock_owner), plock); return plock; @@ -2454,6 +2456,7 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, struct fuse_file_info *fi) { + g_auto(TempFd) inode_fd = TEMP_FD_INIT; struct lo_inode *inode = lo_inode(req, ino); struct lo_data *lo = lo_data(req); int res; @@ -2468,11 +2471,12 @@ static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, } if (!fi) { - fd = lo_inode_open(lo, inode, O_RDWR); - if (fd < 0) { - res = -fd; + res = lo_inode_open(lo, inode, O_RDWR, &inode_fd); + if (res < 0) { + res = -res; goto out; } + fd = inode_fd.fd; } else { fd = lo_fi_fd(req, fi); } @@ -2482,9 +2486,6 @@ static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, } else { res = fsync(fd) == -1 ? errno : 0; } - if (!fi) { - close(fd); - } out: lo_inode_put(lo, &inode); fuse_reply_err(req, res); @@ -3047,7 +3048,6 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, struct lo_inode *inode; ssize_t ret; int saverr; - int fd = -1; if (block_xattr(lo, in_name)) { fuse_reply_err(req, EOPNOTSUPP); @@ -3099,12 +3099,12 @@ 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 = lo_inode_open(lo, inode, O_RDONLY); - if (fd < 0) { - saverr = -fd; + ret = lo_inode_open(lo, inode, O_RDONLY, &inode_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = fgetxattr(fd, name, value, size); + ret = fgetxattr(inode_fd.fd, name, value, size); saverr = ret == -1 ? errno : 0; } else { ret = lo_inode_fd(inode, &inode_fd); @@ -3133,10 +3133,6 @@ static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, fuse_reply_xattr(req, ret); } out_free: - if (fd >= 0) { - close(fd); - } - lo_inode_put(lo, &inode); return; @@ -3157,7 +3153,6 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) struct lo_inode *inode; ssize_t ret; int saverr; - int fd = -1; inode = lo_inode(req, ino); if (!inode) { @@ -3181,12 +3176,12 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) } if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = lo_inode_open(lo, inode, O_RDONLY); - if (fd < 0) { - saverr = -fd; + ret = lo_inode_open(lo, inode, O_RDONLY, &inode_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = flistxattr(fd, value, size); + ret = flistxattr(inode_fd.fd, value, size); saverr = ret == -1 ? errno : 0; } else { ret = lo_inode_fd(inode, &inode_fd); @@ -3273,10 +3268,6 @@ static void lo_listxattr(fuse_req_t req, fuse_ino_t ino, size_t size) fuse_reply_xattr(req, ret); } out_free: - if (fd >= 0) { - close(fd); - } - lo_inode_put(lo, &inode); return; @@ -3299,7 +3290,6 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, struct lo_inode *inode; ssize_t ret; int saverr; - int fd = -1; bool switched_creds = false; bool cap_fsetid_dropped = false; struct lo_cred old = {}; @@ -3345,9 +3335,9 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, */ open_inode = S_ISREG(inode->filetype) || S_ISDIR(inode->filetype); if (open_inode) { - fd = lo_inode_open(lo, inode, O_RDONLY); - if (fd < 0) { - saverr = -fd; + ret = lo_inode_open(lo, inode, O_RDONLY, &inode_fd); + if (ret < 0) { + saverr = -ret; goto out; } } else { @@ -3382,8 +3372,7 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, switched_creds = true; } if (open_inode) { - assert(fd >= 0); - ret = fsetxattr(fd, name, value, size, flags); + ret = fsetxattr(inode_fd.fd, name, value, size, flags); saverr = ret == -1 ? errno : 0; } else { ret = setxattr(procname, name, value, size, flags); @@ -3402,10 +3391,6 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, } out: - if (fd >= 0) { - close(fd); - } - lo_inode_put(lo, &inode); g_free(mapped_name); fuse_reply_err(req, saverr); @@ -3421,7 +3406,6 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) struct lo_inode *inode; ssize_t ret; int saverr; - int fd = -1; if (block_xattr(lo, in_name)) { fuse_reply_err(req, EOPNOTSUPP); @@ -3457,12 +3441,12 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) name); if (S_ISREG(inode->filetype) || S_ISDIR(inode->filetype)) { - fd = lo_inode_open(lo, inode, O_RDONLY); - if (fd < 0) { - saverr = -fd; + ret = lo_inode_open(lo, inode, O_RDONLY, &inode_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = fremovexattr(fd, name); + ret = fremovexattr(inode_fd.fd, name); saverr = ret == -1 ? errno : 0; } else { ret = lo_inode_fd(inode, &inode_fd); @@ -3479,10 +3463,6 @@ static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) } out: - if (fd >= 0) { - close(fd); - } - lo_inode_put(lo, &inode); g_free(mapped_name); fuse_reply_err(req, saverr);