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 B8B503AC0C4 for ; Tue, 14 Apr 2026 08:20:51 +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=1776154854; cv=none; b=oQwMv4ego1K3aJrc/+JAHzdKjQS+x45EB8Bln9srOJXA1tSQGSLAqJ+5uLmHMZYbM9w2z5hVMV0qpivwOSTMyIEWx6ZahgWjTK6Jh9/fnQMnaK5VjdLeJDDcAwV3c0DIpbtUMqGBdkRIMDJjJwVpqApkmGiO8lIbwYTSySZuUps= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776154854; c=relaxed/simple; bh=0RD9WK7Z8b1cfNWJfuywH/XVdQi+DID7QaHnobdiupA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NLW41Ma7HcKrP+16eR+ZwwgT2Wb9fvB068CvaA9BAlHRnsePWRZkxLOHcMYy++bVBaAGM5aSjQXFepUYozIEnKWYRXY/B0B0+5A6U0EEG+GP/Yq0sDsuYGDCiPWwKzoJ0FvqQjy7vSapYeB9r4KRsqwhm0ubcV4uD7IVWYnRr3o= 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=UhQ7sEM7; 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="UhQ7sEM7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1776154850; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hwkDzJJVkIB8QUWldBqXDsmI02iLpH9t4nRKDWmeUI0=; b=UhQ7sEM7CzkfTp3mySP/6p6NK6Tu5kzW9UQTgxiydkCvwv813rm/k9HYKR0dS7PdBnvX7P XiN5TuDZQ38CHf+Vlmdkf0O8O1LJJOlsywebKRHHy1/MamZGFBKORCXIUgsuNmTII15tlY NkvKmaIuDu/irNGRrGeujeeN6C8uivY= Received: from mx-prod-mc-03.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-693-m_grForOOaqNqNBiknMCGQ-1; Tue, 14 Apr 2026 04:20:45 -0400 X-MC-Unique: m_grForOOaqNqNBiknMCGQ-1 X-Mimecast-MFC-AGG-ID: m_grForOOaqNqNBiknMCGQ_1776154844 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 235601956066; Tue, 14 Apr 2026 08:20:44 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.44.34.160]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7451C19560AB; Tue, 14 Apr 2026 08:20:40 +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, Paulo Alcantara , Matthew Wilcox Subject: [PATCH v2 6/7] netfs: Fix zeropoint update where i_size > remote_i_size Date: Tue, 14 Apr 2026 09:20:02 +0100 Message-ID: <20260414082004.3756080-7-dhowells@redhat.com> In-Reply-To: <20260414082004.3756080-1-dhowells@redhat.com> References: <20260414082004.3756080-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 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. 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 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index d8e8a4b59768..e386cf31eb1e 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -302,7 +302,7 @@ bool netfs_release_folio(struct folio *folio, gfp_t gfp) if (folio_test_dirty(folio)) return false; - end = umin(folio_next_pos(folio), i_size_read(&ctx->inode)); + end = umin(folio_next_pos(folio), ctx->remote_i_size); if (end > ctx->zero_point) ctx->zero_point = end;