From patchwork Thu Sep 16 08:40:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 12498281 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 9A312C433F5 for ; Thu, 16 Sep 2021 08:44:17 +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 0344C6120C for ; Thu, 16 Sep 2021 08:44:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0344C6120C 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]:44486 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mQn0C-00085B-6U for qemu-devel@archiver.kernel.org; Thu, 16 Sep 2021 04:44:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48296) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQmxy-0005Cb-5A for qemu-devel@nongnu.org; Thu, 16 Sep 2021 04:41:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:51317) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQmxv-0004mw-RM for qemu-devel@nongnu.org; Thu, 16 Sep 2021 04:41:57 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631781715; 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=QHb/m7LNWzjjVHgHsiAfXIOJoC+uV/r0UT9ieBKPj4Y=; b=ZYFppFhnITM2TBti1KgjltOWwdBRvZYDwApwephYBHaEqTJ0ahSPiYk5FQNeUG7QzCShU5 4MyniR69He43V5H6gw0LD+ila7kWiKWquU2C+wKPpT66z8debqNNRR5oWZLb/l5JteHYO9 k4IwwNYbtOMuYsspWgQixlHIvz9e6Dk= 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-221-XvnP1lmYMoiiSNwPXhSa_w-1; Thu, 16 Sep 2021 04:41:51 -0400 X-MC-Unique: XvnP1lmYMoiiSNwPXhSa_w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 11027835DE1 for ; Thu, 16 Sep 2021 08:41:51 +0000 (UTC) Received: from localhost (unknown [10.39.192.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 706085D9F4; Thu, 16 Sep 2021 08:41:43 +0000 (UTC) From: Hanna Reitz To: qemu-devel@nongnu.org, virtio-fs@redhat.com Subject: [PATCH v4 07/12] virtiofsd: Let lo_inode_open() return a TempFd Date: Thu, 16 Sep 2021 10:40:40 +0200 Message-Id: <20210916084045.31684-8-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 10.5.11.14 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" 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. The auto-cleanup is nice, though. Also, we get a more unified interface where you always get a TempFd when you need an FD for an lo_inode (regardless of whether it is an O_PATH FD or a non-O_PATH FD). Signed-off-by: Hanna Reitz --- tools/virtiofsd/passthrough_ll.c | 156 +++++++++++++++---------------- 1 file changed, 75 insertions(+), 81 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 3bf20b8659..d257eda129 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -293,10 +293,8 @@ 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; @@ -309,10 +307,8 @@ static __attribute__((unused)) int temp_fd_steal(TempFd *temp_fd) /** * Create a borrowing copy of an existing TempFd. Note that *to is * only valid as long as *from is valid. - * - * (TODO: Remove __attribute__ once this is used.) */ -static __attribute__((unused)) void temp_fd_copy(const TempFd *from, TempFd *to) +static void temp_fd_copy(const TempFd *from, TempFd *to) { *to = (TempFd) { .fd = from->fd, @@ -689,9 +685,12 @@ 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) + int open_flags, TempFd *tfd) { g_autofree char *fd_str = g_strdup_printf("%d", inode->fd); int fd; @@ -710,7 +709,13 @@ 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) @@ -854,7 +859,8 @@ static int lo_fi_fd(fuse_req_t req, struct fuse_file_info *fi) static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, int valid, struct fuse_file_info *fi) { - g_auto(TempFd) path_fd = TEMP_FD_INIT; + g_auto(TempFd) path_fd = TEMP_FD_INIT; /* at least an O_PATH fd */ + g_auto(TempFd) rw_fd = TEMP_FD_INIT; /* O_RDWR fd */ int saverr; char procname[64]; struct lo_data *lo = lo_data(req); @@ -868,7 +874,15 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr, return; } - res = lo_inode_fd(inode, &path_fd); + if (!fi && (valid & FUSE_SET_ATTR_SIZE)) { + /* We need an O_RDWR FD for ftruncate() */ + res = lo_inode_open(lo, inode, O_RDWR, &rw_fd); + if (res >= 0) { + temp_fd_copy(&rw_fd, &path_fd); + } + } else { + res = lo_inode_fd(inode, &path_fd); + } if (res < 0) { saverr = -res; goto out_err; @@ -916,18 +930,12 @@ 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; - } + assert(rw_fd.fd >= 0); + truncfd = rw_fd.fd; } saverr = drop_security_capability(lo, truncfd); if (saverr) { - if (!fi) { - close(truncfd); - } goto out_err; } @@ -935,9 +943,6 @@ 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; } } @@ -950,9 +955,6 @@ 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; } @@ -1840,11 +1842,13 @@ 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) rd_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); @@ -1858,14 +1862,16 @@ 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, &rd_fd); + if (res < 0) { + error = -res; goto out_err; } + fd = temp_fd_steal(&rd_fd); d->dp = fdopendir(fd); if (d->dp == NULL) { + close(fd); goto out_errno; } @@ -1895,8 +1901,6 @@ out_err: if (d) { if (d->dp) { closedir(d->dp); - } else if (fd != -1) { - close(fd); } free(d); } @@ -2096,6 +2100,7 @@ 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) opened_fd = TEMP_FD_INIT; ssize_t fh; int fd = existing_fd; int err; @@ -2112,16 +2117,18 @@ 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, &opened_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(&opened_fd); + if (fi->flags & (O_TRUNC)) { int err = drop_security_capability(lo, fd); if (err) { @@ -2231,8 +2238,9 @@ 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) rw_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)); @@ -2249,15 +2257,15 @@ 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, &rw_fd); + if (res < 0) { + *err = -res; free(plock); return NULL; } plock->lock_owner = lock_owner; - plock->fd = fd; + plock->fd = temp_fd_steal(&rw_fd); g_hash_table_insert(inode->posix_locks, GUINT_TO_POINTER(plock->lock_owner), plock); return plock; @@ -2473,6 +2481,7 @@ 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) rw_fd = TEMP_FD_INIT; struct lo_inode *inode = lo_inode(req, ino); struct lo_data *lo = lo_data(req); int res; @@ -2487,11 +2496,12 @@ 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, &rw_fd); + if (res < 0) { + res = -res; goto out; } + fd = rw_fd.fd; } else { fd = lo_fi_fd(req, fi); } @@ -2501,9 +2511,6 @@ 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); @@ -3065,7 +3072,6 @@ 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); @@ -3117,12 +3123,14 @@ 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; + g_auto(TempFd) rd_fd = TEMP_FD_INIT; + + ret = lo_inode_open(lo, inode, O_RDONLY, &rd_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = fgetxattr(fd, name, value, size); + ret = fgetxattr(rd_fd.fd, name, value, size); saverr = ret == -1 ? errno : 0; } else { g_auto(TempFd) path_fd = TEMP_FD_INIT; @@ -3153,10 +3161,6 @@ 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; @@ -3176,7 +3180,6 @@ 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) { @@ -3200,12 +3203,14 @@ 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; + g_auto(TempFd) rd_fd = TEMP_FD_INIT; + + ret = lo_inode_open(lo, inode, O_RDONLY, &rd_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = flistxattr(fd, value, size); + ret = flistxattr(rd_fd.fd, value, size); saverr = ret == -1 ? errno : 0; } else { g_auto(TempFd) path_fd = TEMP_FD_INIT; @@ -3294,10 +3299,6 @@ 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; @@ -3312,14 +3313,14 @@ 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) { - g_auto(TempFd) path_fd = TEMP_FD_INIT; + g_auto(TempFd) path_fd = TEMP_FD_INIT; /* O_PATH fd */ + g_auto(TempFd) rd_fd = TEMP_FD_INIT; /* O_RDONLY fd */ const char *name; char *mapped_name; struct lo_data *lo = lo_data(req); 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 = {}; @@ -3364,9 +3365,9 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, * setxattr() on the link's filename there. */ 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, &rd_fd); + if (ret < 0) { + saverr = -ret; goto out; } } else { @@ -3401,8 +3402,8 @@ static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, } switched_creds = true; } - if (fd >= 0) { - ret = fsetxattr(fd, name, value, size, flags); + if (rd_fd.fd >= 0) { + ret = fsetxattr(rd_fd.fd, name, value, size, flags); saverr = ret == -1 ? errno : 0; } else { char procname[64]; @@ -3424,10 +3425,6 @@ out: FCHDIR_NOFAIL(lo->root.fd); } - if (fd >= 0) { - close(fd); - } - lo_inode_put(lo, &inode); g_free(mapped_name); fuse_reply_err(req, saverr); @@ -3442,7 +3439,6 @@ 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); @@ -3478,12 +3474,14 @@ 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; + g_auto(TempFd) rd_fd = TEMP_FD_INIT; + + ret = lo_inode_open(lo, inode, O_RDONLY, &rd_fd); + if (ret < 0) { + saverr = -ret; goto out; } - ret = fremovexattr(fd, name); + ret = fremovexattr(rd_fd.fd, name); saverr = ret == -1 ? errno : 0; } else { g_auto(TempFd) path_fd = TEMP_FD_INIT; @@ -3502,10 +3500,6 @@ 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);