From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 51C234DA530 for ; Tue, 12 May 2026 12:34:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778589295; cv=none; b=ZwemlPSr9nPtztz1rQ17Hfy4X22n/0q42UoG+IK6XoIznXdK++/IG9LjTf8KYBjFyWKhyUicDO7rgDS5p54/NyJWVEOF7bnvF4JlymK2di0ureEjfkTsi0xj4Xssgl1fcXGrndmO66R7QXkKkc/YPNiBkxVYcUjTnaXOa9cqTLA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778589295; c=relaxed/simple; bh=kH2BSvmx5Q1EY9F+RZfYnqXBcDlpAxhRJhPQmFL2Vos=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:content-type; b=kEuWxdT4cXqhmtENSwdExFnBBI3OSXdOoNzlkivceHZQjmVmzHdd4ehWz/2rMZbsgNf6EiQ1h5WCICcFv6m1e/I0zU8dtc9uMzl52PtL8X3Fn8LdbtAZFb4grvev6vWmOreyVBzhH8RKsh8GFPHCWHwV1wlB4Axplyrm5liMrVU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=EVkEzHK3; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EVkEzHK3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778589283; 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=dKFEhcvCtkYMIbqpl8EHYZ581sy2cf3WKNpQ3LTNaCY=; b=EVkEzHK3yCSqBP8mfE8C9thDZ2SvT4vPWPbpTdt8Huxl73Bwvvo3wTb6qVAYnPLaodj4uE /DDDlX3C774SSFC9K4S9QuhuE3BV0gh+6gQYilSDsr1KLLyxSyj3fg3vCpL/xpJKtid1Nc QA2qfV7CcCUk2Ai21WHL0/NgQUp8A0Q= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-669-TDHRvqUWNCubhmtN7ABLcQ-1; Tue, 12 May 2026 08:34:42 -0400 X-MC-Unique: TDHRvqUWNCubhmtN7ABLcQ-1 X-Mimecast-MFC-AGG-ID: TDHRvqUWNCubhmtN7ABLcQ_1778589280 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3E986195608A; Tue, 12 May 2026 12:34:40 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.48.83]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 29F2C180034E; Tue, 12 May 2026 12:34:36 +0000 (UTC) From: David Howells To: Christian Brauner Cc: David Howells , Paulo Alcantara , netfs@lists.linux.dev, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Matthew Wilcox Subject: [PATCH v6 06/24] netfs: Fix zeropoint update where i_size > remote_i_size Date: Tue, 12 May 2026 13:33:43 +0100 Message-ID: <20260512123404.719402-7-dhowells@redhat.com> In-Reply-To: <20260512123404.719402-1-dhowells@redhat.com> References: <20260512123404.719402-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: netfs@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: D4S2CgJ8cs4RHsNQcTOfayHXX5q9cJvg5In7rP_Gy9A_1778589280 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit content-type: text/plain; charset="US-ASCII"; x-default=true Fix the update of the zero point[*] by netfs_release_folio() when there is uncommitted data in the pagecache beyond the folio being released but the on-server EOF is in this folio (ie. i_size > remote_i_size). The update needs to limit zero_point to remote_i_size, not i_size as i_size is a local phenomenon reflecting updates made locally to the pagecache, not stuff written to the server. remote_i_size tracks the server's i_size. [*] The zero point is the file position from which we can assume that the server will just return zeros, so we can avoid generating reads. Note that netfs_invalidate_folio() probably doesn't need fixing as zero_point should be updated by setattr after truncation or fallocate. Found with: fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \ /xfstest.test/junk --replay-ops=junk.fsxops using the following as junk.fsxops: truncate 0x0 0x1bbae 0x82864 write 0x3ef2e 0xf9c8 0x1bbae write 0x67e05 0xcb5a 0x4e8f6 mapread 0x57781 0x85b6 0x7495f copy_range 0x5d3d 0x10329 0x54fac 0x7495f write 0x64710 0x1c2b 0x7495f mapread 0x64000 0x1000 0x7495f on cifs with the default cache option. It shows read-gaps on folio 0x64 failing with a short read (ie. it hits EOF) if the FMODE_READ check is commented out in netfs_perform_write(): if (//(file->f_mode & FMODE_READ) || netfs_is_cache_enabled(ctx)) { and no fscache. This was initially found with the generic/522 xfstest. Fixes: cce6bfa6ca0e ("netfs: Fix trimming of streaming-write folios in netfs_inval_folio()") Signed-off-by: David Howells cc: Paulo Alcantara cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org --- fs/netfs/misc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index bad661ff2bec..723571ca1b88 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -307,10 +307,10 @@ bool netfs_release_folio(struct folio *folio, gfp_t gfp) return false; netfs_read_sizes(inode, &i_size, &remote_i_size, &zero_point); - end = umin(folio_next_pos(folio), i_size); + end = folio_next_pos(folio); if (end > zero_point) { spin_lock(&inode->i_lock); - end = umin(folio_next_pos(folio), inode->i_size); + end = umin(end, ctx->_remote_i_size); if (end > ctx->_zero_point) netfs_write_zero_point(inode, end); spin_unlock(&inode->i_lock);