From patchwork Thu Feb 22 20:30:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 13568061 Received: from fanzine2.igalia.com (fanzine2.igalia.com [213.97.179.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F325C29CEA; Thu, 22 Feb 2024 20:30:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.97.179.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708633843; cv=none; b=XTV5ZlyFKumEBfyILuZbHIPMMMc51vcPETUmQzOd3Waz9Qks+x4Q8MUsnDVuUbUL/LaQSJV/DLRVt0YaF4qeJfr8tz8yw/wPhbrzL9kXm4ZsimAIkOBe/NLRLiZ9ZaAW5qQOJwGGDknNV7n2fFHw+0+HPBLSLEok1XZ6mK8TG2I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708633843; c=relaxed/simple; bh=PGw/6elJRjzjT5oami1yJD74wKwg8urvYRLz170UPWU=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=a0gMP9lMZvuMcpFVCY6yzKw8SuTGC80XtmjIlCuWbBs7LzpMGoAtdxoI5gwFy5tRTNBAfFC/rTRtGnrgHFNwUOOrrvAGklvO0J96m5z4slSmOujeA7rlWktXYdEBLAFfErSUoPcdbyUwRlPiqCqnU/+vYr5Wjen8sEZe3dH8YEE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com; spf=pass smtp.mailfrom=igalia.com; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b=JGZc1gqk; arc=none smtp.client-ip=213.97.179.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=igalia.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=igalia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=igalia.com header.i=@igalia.com header.b="JGZc1gqk" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject: Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=uDD88zaVrMvSV7jyXIjccldv2PnZ3aOybLZ9ITuOEPM=; b=JGZc1gqkZdMeL5Y4Bsdn/FPyaq DFOTfRXZTGmrEQmBgQ5yBj0Dbf9dCT8o6LG1NZ7WjVclxxUFMHtPouewiUtOBODiJaaefLnY6LK74 wVx+P36s6ULKZM2OqnQX2+63eY3fP4Sda0nDOHVqFGm6/hTL2xwheMFdsp9jSvVN3jeqtddSS9kdS wdG7m+AgLId0wB3PGptDb5agHuynLsV9VSrPbxGJIp9pvk7TCbjMGCzM4zx4z6rfRAla3N6mFFSn3 OSSUPSWcdYyrEPhPB8qnL+l75+Sbcc26ihMXCNfye6Uyh3b391GsEFcx9TNbnV8zAQL5/a+U1wovK zRamh19Q==; Received: from 179-125-75-196-dinamico.pombonet.net.br ([179.125.75.196] helo=quatroqueijos.lan) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1rdFi4-002SRK-9F; Thu, 22 Feb 2024 21:30:24 +0100 From: Thadeu Lima de Souza Cascardo To: OGAWA Hirofumi Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Gwendal Grignou , dlunev@chromium.org, Thadeu Lima de Souza Cascardo Subject: [PATCH] fat: ignore .. subdir and always add a link to dirs Date: Thu, 22 Feb 2024 17:30:13 -0300 Message-Id: <20240222203013.2649457-1-cascardo@igalia.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The tools used for creating images for the Lego Mindstrom EV3 are not adding '.' and '..' entry in the 'Projects' directory. Without this fix, the kernel can not fill the inode structure for 'Projects' directory. See https://github.com/microsoft/pxt-ev3/issues/980 And https://github.com/microsoft/uf2-linux/issues/6 When counting the number of subdirs, ignore .. subdir and add one when setting the initial link count for directories. This way, when .. is present, it is still accounted for, and when neither . or .. are present, a single link is still done, as it should, since this link would be the one from the parent directory. With this fix applied, we can mount an image with such empty directories, access them, create subdirectories and remove them. Signed-off-by: Thadeu Lima de Souza Cascardo Cc: Gwendal Grignou Link: https://lore.kernel.org/all/20220204062232.3410036-1-gwendal@chromium.org/ Cc: dlunev@chromium.org --- fs/fat/dir.c | 3 ++- fs/fat/inode.c | 12 +++++++++--- 2 files changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/fat/dir.c b/fs/fat/dir.c index 00235b8a1823..fcdb652efc53 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -937,7 +937,8 @@ int fat_subdirs(struct inode *dir) bh = NULL; cpos = 0; while (fat_get_short_entry(dir, &cpos, &bh, &de) >= 0) { - if (de->attr & ATTR_DIR) + if (de->attr & ATTR_DIR && + strncmp(de->name, MSDOS_DOTDOT, MSDOS_NAME)) count++; } brelse(bh); diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 1fac3dabf130..9a3bd38a4494 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -494,8 +494,14 @@ static int fat_validate_dir(struct inode *dir) { struct super_block *sb = dir->i_sb; - if (dir->i_nlink < 2) { - /* Directory should have "."/".." entries at least. */ + if (dir->i_nlink < 1) { + /* + * Though it is expected that directories have at least + * "."/".." entries, there are filesystems in the field that + * don't have either. Even in those cases, at least one link + * is necessary, as otherwise, when trying to increment it, + * VFS would BUG. + */ fat_fs_error(sb, "corrupted directory (invalid entries)"); return -EIO; } @@ -534,7 +540,7 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de) return error; MSDOS_I(inode)->mmu_private = inode->i_size; - set_nlink(inode, fat_subdirs(inode)); + set_nlink(inode, fat_subdirs(inode) + 1); error = fat_validate_dir(inode); if (error < 0)