From patchwork Wed Feb 12 13:57:11 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 13971678 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 B916E20F08D for ; Wed, 12 Feb 2025 13:55:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739368504; cv=none; b=PsL6EGKJurVuUBLsvnLytu39pdyASCJd+JmCeHxDrSmHhfzNHI0tQbQxQeGlJkQjMuXYLWUNmr142KoAxVqUifWyecVvvnFs8LXynRQy1YhOYCSgc8MO5XOonod2UdzMfPKbt6qind7mIWKDw/qtwaKKgMEG0FV/89ONSsO0cbg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739368504; c=relaxed/simple; bh=wZocs5mOUOJ+TlTcBxDM69hLj9fXjrxceDAHj/K5GIQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=eCy0HEiyZP/lYopWEbBElrCtltNOoXbUIySPOGkwJ7sYNOU2lgtj6u+P7zrRz+2nWS3ZyiuwtMdzseB+1KCHq018LncGaD+ziCxLoTRY9zoYzzuLhuzYc2tUscHSO/3HHrsg4LFMGtvP8Au0GIw6AQmgGxfdevN5SOeq0Kjms9E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none 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=ed94YXJx; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none 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="ed94YXJx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739368502; 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=muK/bdU+k1VahRDlOLNbg1jEYHDNB8xWcVNTZs/j96M=; b=ed94YXJxgcrYxvGOHkmAa56YJ/Usmq4bl6sdWrOKd+H4MpuVrWqwZ9rw48genP4xbo+/xK 4q3wGzYSpW32F9dmc5rP5tUUZnSN/cQEWYYkePl25JwOAKss7eNBuKysIRp09cheJiWfxP 2xNykQ+ibmYtYGRvabVzNd/YApXfZ8w= Received: from mx-prod-mc-04.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-556-msijBRnCPpyl8NnfBctznQ-1; Wed, 12 Feb 2025 08:54:58 -0500 X-MC-Unique: msijBRnCPpyl8NnfBctznQ-1 X-Mimecast-MFC-AGG-ID: msijBRnCPpyl8NnfBctznQ Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9C80C1955D82; Wed, 12 Feb 2025 13:54:57 +0000 (UTC) Received: from bfoster.redhat.com (unknown [10.22.88.88]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A90AA3001D10; Wed, 12 Feb 2025 13:54:56 +0000 (UTC) From: Brian Foster To: linux-fsdevel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, Christoph Hellwig , "Darrick J . Wong" Subject: [PATCH 09/10] iomap: remove unnecessary advance from iomap_iter() Date: Wed, 12 Feb 2025 08:57:11 -0500 Message-ID: <20250212135712.506987-10-bfoster@redhat.com> In-Reply-To: <20250212135712.506987-1-bfoster@redhat.com> References: <20250212135712.506987-1-bfoster@redhat.com> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 At this point, all iomap operations have been updated to advance the iomap_iter directly before returning to iomap_iter(). Therefore, the complexity of handling both the old and new semantics is no longer required and can be removed from iomap_iter(). Update iomap_iter() to expect success or failure status in iter.processed. As a precaution and developer hint to prevent inadvertent use of old semantics, warn on a positive return code and fail the operation. Remove the unnecessary advance and simplify the termination logic. Signed-off-by: Brian Foster --- fs/iomap/iter.c | 38 ++++++++++++++------------------------ 1 file changed, 14 insertions(+), 24 deletions(-) diff --git a/fs/iomap/iter.c b/fs/iomap/iter.c index 0ebcabc7df52..1e2e5c834582 100644 --- a/fs/iomap/iter.c +++ b/fs/iomap/iter.c @@ -60,9 +60,8 @@ static inline void iomap_iter_done(struct iomap_iter *iter) int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) { bool stale = iter->iomap.flags & IOMAP_F_STALE; - ssize_t advanced = iter->processed > 0 ? iter->processed : 0; - u64 olen = iter->len; - s64 processed; + ssize_t advanced; + u64 olen; int ret; trace_iomap_iter(iter, ops, _RET_IP_); @@ -71,14 +70,11 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) goto begin; /* - * If iter.processed is zero, the op may still have advanced the iter - * itself. Calculate the advanced and original length bytes based on how - * far pos has advanced for ->iomap_end(). + * Calculate how far the iter was advanced and the original length bytes + * for ->iomap_end(). */ - if (!advanced) { - advanced = iter->pos - iter->iter_start_pos; - olen += advanced; - } + advanced = iter->pos - iter->iter_start_pos; + olen = iter->len + advanced; if (ops->iomap_end) { ret = ops->iomap_end(iter->inode, iter->iter_start_pos, @@ -89,26 +85,20 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) return ret; } - processed = iter->processed; - if (processed < 0) { - iomap_iter_reset_iomap(iter); - return processed; - } + /* detect old return semantics where this would advance */ + if (WARN_ON_ONCE(iter->processed > 0)) + iter->processed = -EIO; /* - * Advance the iter and clear state from the previous iteration. This - * passes iter->processed because that reflects the bytes processed but - * not yet advanced by the iter handler. - * * Use iter->len to determine whether to continue onto the next mapping. - * Explicitly terminate in the case where the current iter has not + * Explicitly terminate on error status or if the current iter has not * advanced at all (i.e. no work was done for some reason) unless the * mapping has been marked stale and needs to be reprocessed. */ - ret = iomap_iter_advance(iter, &processed); - if (!ret && iter->len > 0) - ret = 1; - if (ret > 0 && !advanced && !stale) + ret = (iter->len > 0) ? 1 : 0; + if (iter->processed < 0) + ret = iter->processed; + else if (!advanced && !stale) ret = 0; iomap_iter_reset_iomap(iter); if (ret <= 0)