From patchwork Mon Jun 26 14:53:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adhemerval Zanella Netto X-Patchwork-Id: 21266 Received: (qmail 77170 invoked by alias); 26 Jun 2017 14:53:55 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 77121 invoked by uid 89); 26 Jun 2017 14:53:54 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.4 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=3423, Hx-languages-length:5197 X-HELO: mail-qt0-f176.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ZlMDQLF92CKh2s8uEh0e7pjtgv2hhaYxpYvCB1ks+gk=; b=UodNfdi97lNhro1nYJY63gXtjHBgg03nTvjuil9BrEuOurlGUg0tpzC/hiTU7z+9KM ErlhubN5rBAVbBRTjzhkouzn5QM4yw5G4PSZbYCmGQaWYjxVg8x2yza4oy1kWSI949E4 BRewXLpaA4TtHGot2nRc7hCvQ2w6H6fYgwl3PP9+61zzZ6shz6y3lvLPZFmz1NPr5Afw ZpgXUazFprP+RdEEDUCxopQsI+u/gbxX1+miAlLtuAO0KbYYIO45+JCpCRdZ3znhDlIg XLmMRQXu5UOhxE1CgG+BjlzpCTxp1ScsQjmrYhxj2CJ3r9BiOAFL0MC7V0FrIsGWT9F4 Us1w== X-Gm-Message-State: AKS2vOxqJFLbdv3gJVX6o+tzAmZ1H+0DHdZVbtu1/zeGjyqCazISG4mq Ik2I5OfIGBF1124kASa+PQ== X-Received: by 10.237.61.47 with SMTP id g44mr816205qtf.60.1498488830082; Mon, 26 Jun 2017 07:53:50 -0700 (PDT) Subject: Re: [PATCH] Implement tmpfile with O_TMPFILE (bug 21530) To: libc-alpha@sourceware.org References: From: Adhemerval Zanella Message-ID: Date: Mon, 26 Jun 2017 11:53:47 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: On 26/06/2017 08:47, Andreas Schwab wrote: > If the kernel or the file system does not support O_TMPFILE fall back to > creating a temporary file based on tmpnam. > > [BZ #21530] > * stdio-common/tmpfile.c (tmpfile) [O_TMPFILE]: Try opening an > unnamed file first. > --- > stdio-common/tmpfile.c | 51 ++++++++++++++++++++++++++++++++++++-------------- > 1 file changed, 37 insertions(+), 14 deletions(-) I would prefer to compartmentalize Linuxism to linux sysdep folder, something like: diff --git a/include/stdio.h b/include/stdio.h index f68f633..92fc0e2 100644 --- a/include/stdio.h +++ b/include/stdio.h @@ -181,5 +181,8 @@ libc_hidden_proto (__obstack_vprintf_chk) extern FILE * __fmemopen (void *buf, size_t len, const char *mode); libc_hidden_proto (__fmemopen) +extern int __gen_tempfd (int flags); +libc_hidden_proto (__gen_tempfd) + # endif /* not _ISOMAC */ #endif /* stdio.h */ diff --git a/stdio-common/Makefile b/stdio-common/Makefile index 01a6dd0..cc6bb8f 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -39,7 +39,7 @@ routines := \ flockfile ftrylockfile funlockfile \ isoc99_scanf isoc99_vscanf isoc99_fscanf isoc99_vfscanf isoc99_sscanf \ isoc99_vsscanf \ - psiginfo + psiginfo gentempfd aux := errlist siglist printf-parsemb printf-parsewc fxprintf diff --git a/stdio-common/gentempfd.c b/stdio-common/gentempfd.c new file mode 100644 index 0000000..d40c57d --- /dev/null +++ b/stdio-common/gentempfd.c @@ -0,0 +1,26 @@ +/* Generate a temporary file descriptor. Generic/POSIX version. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include + +int +__gen_tempfd (int flags) +{ + return -1; +} +libc_hidden_def (__gen_tempfd) diff --git a/stdio-common/tmpfile.c b/stdio-common/tmpfile.c index e6030be..012659b 100644 --- a/stdio-common/tmpfile.c +++ b/stdio-common/tmpfile.c @@ -26,7 +26,6 @@ # define tmpfile __new_tmpfile #endif - /* This returns a new stream opened on a temporary file (generated by tmpnam). The file is opened with mode "w+b" (binary read/write). If we couldn't generate a unique filename or the file couldn't @@ -34,23 +33,34 @@ FILE * tmpfile (void) { - char buf[FILENAME_MAX]; int fd; FILE *f; - - if (__path_search (buf, FILENAME_MAX, NULL, "tmpf", 0)) - return NULL; int flags = 0; #ifdef FLAGS flags = FLAGS; #endif - fd = __gen_tempname (buf, 0, flags, __GT_FILE); + + /* First try a system specific method. */ + fd = __gen_tempfd (flags); + if (fd < 0) - return NULL; + { + char buf[FILENAME_MAX]; - /* Note that this relies on the Unix semantics that - a file is not really removed until it is closed. */ - (void) __unlink (buf); + if (__path_search (buf, sizeof buf, NULL, "tmpf", 0)) + return NULL; + + fd = __gen_tempname (buf, 0, flags, __GT_FILE); + if (fd < 0) + return NULL; + + /* Note that this relies on the Unix semantics that + a file is not really removed until it is closed. */ + (void) __unlink (buf); + } + + if (fd < 0) + return NULL; if ((f = __fdopen (fd, "w+b")) == NULL) __close (fd); diff --git a/sysdeps/unix/sysv/linux/gentempfd.c b/sysdeps/unix/sysv/linux/gentempfd.c new file mode 100644 index 0000000..902cbe2 --- /dev/null +++ b/sysdeps/unix/sysv/linux/gentempfd.c @@ -0,0 +1,34 @@ +/* Generate a temporary file descriptor. Linux version. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include + +int +__gen_tempfd (int flags) +{ + int fd = __open (P_tmpdir, O_RDWR | O_TMPFILE | O_EXCL | flags, + S_IRUSR | S_IWUSR); + if (fd < 0 && errno == ENOENT && strcmp (P_tmpdir, "/tmp") != 0) + fd = __open ("/tmp", O_RDWR | O_TMPFILE | O_EXCL | flags, + S_IRUSR | S_IWUSR); + + return fd; +} +libc_hidden_def (__gen_tempfd)