From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D28B2C43334 for ; Mon, 11 Jul 2022 13:20:28 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id A8EA13CA6EF for ; Mon, 11 Jul 2022 15:20:26 +0200 (CEST) Received: from in-5.smtp.seeweb.it (in-5.smtp.seeweb.it [217.194.8.5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id A34F53CA4A5 for ; Mon, 11 Jul 2022 15:20:16 +0200 (CEST) Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-5.smtp.seeweb.it (Postfix) with ESMTPS id E46E360076D for ; Mon, 11 Jul 2022 15:20:15 +0200 (CEST) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id DC89B22888; Mon, 11 Jul 2022 13:20:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1657545614; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nX/qIF24sIotylGD4es/nvhZByqYs6L1OONQfuxDWVk=; b=yvqBgeFhUmwYKN6ALQ8+rwcaKPen1InvHyOv8bNSdFa1PgY7mXSugxCKKl8/cUzGGxyond /57YZFRxEAcR7VGMFZ3A8KH15sPdZSX/naTEVt78WIDwx9tb2O6t3saDJw8SuhkhHYHM8P ZKmVjGqzTjFf43GcmcsU1vjv9gd9acQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1657545614; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nX/qIF24sIotylGD4es/nvhZByqYs6L1OONQfuxDWVk=; b=QvZYIbmmDoGZFZvE8LHmW1uMxf+UaCyzGZ4Wpztxye3vsvqP5ZsQdGkdZbnbYwpiGkP54F 2+Mnkdq9hpSa7UAw== Received: from g78 (unknown [10.163.24.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 9EDA42C141; Mon, 11 Jul 2022 13:20:14 +0000 (UTC) References: <87fsj7onim.fsf@suse.de> User-agent: mu4e 1.6.10; emacs 28.1 From: Richard Palethorpe To: Jan Stancek Date: Mon, 11 Jul 2022 14:11:44 +0100 In-reply-to: Message-ID: <87bktvokfl.fsf@suse.de> MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-5.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] tst_find_backing_dev: fix logic in matching mount point X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: rpalethorpe@suse.de Cc: LTP List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Hello, Jan Stancek writes: > On Mon, Jul 11, 2022 at 2:13 PM Richard Palethorpe wrote: >> >> Hello, >> >> Jan Stancek writes: >> >> > If backing dev is btrfs root device, then starting best_match_len >> > from 1 creates an issue, because root (/) is never matched. >> > Also we should check that entire mount point string is present in >> > path we are matching against. >> > >> > In case there's error also dump /proc/self/mountinfo before tst_brk. >> > >> > This fixes test with following partition layout (TMPDIR is on /): >> > # cat /proc/self/mountinfo | grep btrfs >> > 59 1 0:29 /root / rw,relatime shared:1 - btrfs /dev/dasda2 rw,seclabel,compress=zstd:1,ssd,space_cache=v2,subvolid=257,subvol=/root >> > 93 59 0:29 /home /home rw,relatime shared:47 - btrfs /dev/dasda2 rw,seclabel,compress=zstd:1,ssd,space_cache=v2,subvolid=256,subvol=/home >> > >> > Signed-off-by: Jan Stancek >> > --- >> > lib/tst_device.c | 17 ++++++++++++----- >> > 1 file changed, 12 insertions(+), 5 deletions(-) >> > >> > diff --git a/lib/tst_device.c b/lib/tst_device.c >> > index c34cbe6d1f56..414bf0eea816 100644 >> > --- a/lib/tst_device.c >> > +++ b/lib/tst_device.c >> > @@ -506,12 +506,17 @@ unsigned long tst_dev_bytes_written(const char *dev) >> > return dev_bytes_written; >> > } >> > >> > -static int count_match_len(const char *first, const char *second) >> > +static int str_starts_with(const char *str, const char *prefix) >> > { >> > int len = 0; >> > >> > - while (*first && *first++ == *second++) >> > + while (*prefix) { >> > + if (!*str) >> > + return 0; >> > + if (*str++ != *prefix++) >> > + return 0; >> > len++; >> > + } >> >> I'm not sure this is better than the original. It's a seperate cleanup >> in any case. > > The difference is that partial matches now returns 0. Previously it did not, > it only counted number of matching characters. So for example ("/foobar" "/foo") > appeared as better match than ("/foobar", "/") Ah, sorry. > >> >> > >> > return len; >> > } >> > @@ -524,7 +529,7 @@ void tst_find_backing_dev(const char *path, char *dev) >> > char *pre = NULL; >> > char *next = NULL; >> > unsigned int dev_major, dev_minor, line_mjr, line_mnr; >> > - unsigned int len, best_match_len = 1; >> > + unsigned int len, best_match_len = 0; >> > char mnt_point[PATH_MAX]; >> > >> > if (stat(path, &buf) < 0) >> > @@ -550,7 +555,7 @@ void tst_find_backing_dev(const char *path, char *dev) >> > break; >> > } >> > >> > - len = count_match_len(path, mnt_point); >> > + len = str_starts_with(path, mnt_point); >> > if (len > best_match_len) { >> > strcpy(dev, pre); >> > best_match_len = len; >> > @@ -559,8 +564,10 @@ void tst_find_backing_dev(const char *path, char *dev) >> > >> > SAFE_FCLOSE(NULL, file); >> > >> > - if (!*dev) >> > + if (!*dev) { >> > + tst_system("cat /proc/self/mountinfo"); >> > tst_brkm(TBROK, NULL, "Cannot find block device for %s", path); >> > + } >> > >> > if (stat(dev, &buf) < 0) >> > tst_brkm(TWARN | TERRNO, NULL, "stat(%s) failed", dev); >> > -- >> > 2.27.0 >> >> Makes sense. However I suspect this function can be replaced with the >> standard library method used in tst_stat_mount_dev. I didn't try this >> before because I'm not sure why it scans mountinfo instead of mounts. > > /proc/self/mounts doesn't contain major/minor numbers, which is primarily what > tst_find_backing_dev is using. Does anyone know a situation where checking the mount path doesn't work? It seems like we are just checking the device numbers first for historical reasons and not because it is necessary. I haven't seen any failure reports for io_control01 which only checks the path with tst_stat_mount_dev. However this test only runs if you have CG v2 enabled by default. > >> >> >> -- >> Thank you, >> Richard. >> -- Thank you, Richard. -- Mailing list info: https://lists.linux.it/listinfo/ltp