From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E547431AF0C; Fri, 29 Aug 2025 23:58:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756511921; cv=none; b=Vi+xIZ9MMgkuqGsXwmX+ZhFyUIZ1OKC/eigFkojuYgJeV2cz5KgfgiuTXx3WaIjwLl0VmvIDh2G2EvK3opggRVcwRv55KSyQAa2aV2tZ6alVhtUl+BqPY1NGzPwo6CgOcLs9wvYqdKFt5nSWwbmJCT292OzPVQuIAdn1jpQdbAU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756511921; c=relaxed/simple; bh=DIlpHFkPr9r2IcaB+pqFT4ySOzEm4lOta5iviaZTkeM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YmunxPq20fHq5oywnyJ+S2d5LQ/gSUxUilRG/2JIulZYFl/+5SCou2JlMKYVBeYPcfSaAaRGpXHdbLxpV0smolSiLc8rCZxcpEw/8EeZ233gIod6Jh7anS5F299z0R/JLOOUwg3VWr3koxBo74ZZ1K9pnsU+N8YNJo8WbQf39d8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Cp14i4Co; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Cp14i4Co" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-24a1274cfb1so157005ad.2; Fri, 29 Aug 2025 16:58:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1756511919; x=1757116719; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=zn8sDyIvTxrBue4t1ODFxInW7Pz/mV9YXc1UtehcE5A=; b=Cp14i4Co5EMEVimX8ruToLsPmaUPYhPKRbbgakqmM05hYMe9/9bkSS2KkQYbi3wNn5 +RknzORs6j6N0h84xsdN60sfBr3Yw0H4HkAdqG9XiHsfkdhcSVnbuaMcOvXgv9TQmGoY TUryUGOFQbX0j+29B3UxjvjQMB090AteO2VAa8TeifWYPK2tDqkhcuf8mn6R1vJOPadA EFK4Sp+cFTP5LZzFPNie/lqLic9Kv8lnhpoy+ceKojK1HQEgzGaa/8JqnDv38JmiOHJu +BR3WZguvfSH80s1Cat9Yc5oO/66I1Va1pfFBStXOSs6ie2TvpZBw8jwlGAbfdCpx462 rSYA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1756511919; x=1757116719; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zn8sDyIvTxrBue4t1ODFxInW7Pz/mV9YXc1UtehcE5A=; b=XmUUPd9PyxYVy4uFhEWv1upZNfw2bxlGpsKWzOuhHXNHze6Z0ggv6Ix0riUiM3yCYs Ym6ZqCVH3Sg1/vUqyKARukZ8XwC0qDl+JqfevCicF6BDsWZ7IRoZqnAAmri8u2jSW3QX YV2WPuwg/YaI6XrK9CaYMu1Au1LbuwB3sPsfay87BMdMWDTHaHYtDOExTf46CmD9mF6B J98G/6/hduQFl8iDGf6AcuxTQ4Mf23zTtSplZB5ibWadOd3pIOH9pP7dcHjYv+26RZB2 ChEadAFXfH0qi/OPVLyuJrd4yzvWAV5DmAKiqYLne5wIQPKVX8sIRh3hkbw1xpzdUw1+ AK3w== X-Forwarded-Encrypted: i=1; AJvYcCVnNbx4oFXjvNqdGsJHBt1QSatgEeoBOMliKG1pVFaQy+/YnpQDS2pPB+ptec4qG+o1kRUcfot8OVGp@vger.kernel.org, AJvYcCXBpGECya2Ie7D1zrSD6fDX30BDn+FNg6RRrWOtD/zWrSZeDbWR69TwG0JJAPuhUUIYI/f7vFtN8t8W3buwvQ==@vger.kernel.org, AJvYcCXC1KUvTr8QE6HRNZRqFJbFFipNZ3/YhJRWCAXfIjTCAXTW+l085b6OOb0qdXYCLD8bY4A9IYkQ74Y=@vger.kernel.org X-Gm-Message-State: AOJu0YwIVahtmuRNuYoesP0zCACIjXuNQ0uG+fncKXh+0ONnS/go8oVp Cm7nWkuIQSeAKAu8O1qXA+fDjgTpSNxXeNHbBHG38bW2N00VmZsMotWH X-Gm-Gg: ASbGncvKDSVYdB3F+B5nLUtkPILWuU3rCMtENhIW3tau8rFUj+aR9R1uzCFhOTKLVeR kefhAxaCpUkBKUvxunv9EYGSGnpHHqPkz5LwKdLrnul9LjJxX/AsOGNpsKxczs8wGkPbtkfNtUf cS/yQew2SxpiKt2G5zvOZ8UbKVIs4vRdWz7Q72dIw6hxOqakmOB4mz/eYeqO27ow7J6qvmiQoir R5xmmvAoWwK+jlDmu+wDovOVYimf+F4qL2DsmyymkmfsOGM+wtvvh1DYN4vzWZL45uwSoJV1aB6 jSvqhZjUSnrUx7AODDRRcdGB7EoiriyMnvTwg90bIWbQCs91bNaoLm6S7166jKFUFQM+tsmfNqU 1ybLSakks2vRZWiO5uQ== X-Google-Smtp-Source: AGHT+IHALHHB1104RJNmfTC5QM3Bbyxp+9H4chOY1TYOaWtmbav78Px1Oi5FPbpY9b7sZBnfKz3Ccg== X-Received: by 2002:a17:902:e80d:b0:248:9b4f:f688 with SMTP id d9443c01a7336-2494485db43mr4535705ad.4.1756511919164; Fri, 29 Aug 2025 16:58:39 -0700 (PDT) Received: from localhost ([2a03:2880:ff:41::]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-24906598815sm35229055ad.117.2025.08.29.16.58.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Aug 2025 16:58:38 -0700 (PDT) From: Joanne Koong To: brauner@kernel.org, miklos@szeredi.hu Cc: hch@infradead.org, djwong@kernel.org, linux-fsdevel@vger.kernel.org, kernel-team@meta.com, linux-xfs@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v1 16/16] fuse: remove fuse_readpages_end() null mapping check Date: Fri, 29 Aug 2025 16:56:27 -0700 Message-ID: <20250829235627.4053234-17-joannelkoong@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20250829235627.4053234-1-joannelkoong@gmail.com> References: <20250829235627.4053234-1-joannelkoong@gmail.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Remove extra logic in fuse_readpages_end() that checks against null folio mappings. This was added in commit ce534fb05292 ("fuse: allow splice to move pages"): "Since the remove_from_page_cache() + add_to_page_cache_locked() are non-atomic it is possible that the page cache is repopulated in between the two and add_to_page_cache_locked() will fail. This could be fixed by creating a new atomic replace_page_cache_page() function. fuse_readpages_end() needed to be reworked so it works even if page->mapping is NULL for some or all pages which can happen if the add_to_page_cache_locked() failed." Commit ef6a3c63112e ("mm: add replace_page_cache_page() function") added atomic page cache replacement, which means the check against null mappings can be removed. Signed-off-by: Joanne Koong --- fs/fuse/file.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 1659603f4cb6..87078f40d446 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -981,22 +981,20 @@ static void fuse_readpages_end(struct fuse_mount *fm, struct fuse_args *args, struct fuse_args_pages *ap = &ia->ap; size_t count = ia->read.in.size; size_t num_read = args->out_args[0].size; - struct address_space *mapping = NULL; - - for (i = 0; mapping == NULL && i < ap->num_folios; i++) - mapping = ap->folios[i]->mapping; + struct address_space *mapping; + struct inode *inode; - if (mapping) { - struct inode *inode = mapping->host; + WARN_ON_ONCE(!ap->num_folios); + mapping = ap->folios[0]->mapping; + inode = mapping->host; - /* - * Short read means EOF. If file size is larger, truncate it - */ - if (!err && num_read < count) - fuse_short_read(inode, ia->read.attr_ver, num_read, ap); + /* + * Short read means EOF. If file size is larger, truncate it + */ + if (!err && num_read < count) + fuse_short_read(inode, ia->read.attr_ver, num_read, ap); - fuse_invalidate_atime(inode); - } + fuse_invalidate_atime(inode); for (i = 0; i < ap->num_folios; i++) { iomap_finish_folio_read(ap->folios[i], ap->descs[i].offset, -- 2.47.3