From patchwork Wed Feb 19 17:50:48 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 13982586 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 6B881214A76 for ; Wed, 19 Feb 2025 17:48:31 +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=1739987313; cv=none; b=QSTIHIITeDpjO/nRdh8fVpY0qsmjvML9FefMbNbnvF2XezrwnpTjtcEbd1rdGXGPThlfYKxX67wxVdSCg3c6T5XMXitPgDEEVhl2/EMcK9Sz/XlT9nzZspJcxP73buK94s2tdctC4sz+riOuqfpR4G0PV5GkZc8HWNFncTe5xsQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739987313; c=relaxed/simple; bh=TnLo0J/eX0LfM1VhyElD5c/cWgJqUoCkZM7F07D2x+g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dl8475KYasEfWlBvzvJLYogyfk5sKHyLkw5GhVj8Jftf+8THqERB5vJIPnpbcQx8OUlcnUNqTPKW54bwzMQpmJYjwUI+x9XTpo0/Euqojc1K4wibhDaaEvVcC5Hm3aOTX3pliPK1Zq7vNIlbMI0iKrSzl8UHd45OTjE+/XhaIxc= 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=Uh0Wp73j; arc=none smtp.client-ip=170.10.129.124 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="Uh0Wp73j" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1739987310; 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=ILpaOuAT4xZuSYH/+f+G/YF6BNzFmb/rQwpJXAeyZKY=; b=Uh0Wp73jlcOpnsL38bC5/uuSjT699m9wvkPs6f2B8lV9nC27BmwYTU0LQ4sUOofCsude6l YDs0srIPBqt4PykkWGsZLFfx0dkHVHX6tEtqHkU1QSA3hB1yme++DsI4902hna68xeyxSx 7ngL8M8bR8atbTKR1I3s4M3vE6+c9u4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-261-cipLOEJnPe-XnciPl3jZxA-1; Wed, 19 Feb 2025 12:48:27 -0500 X-MC-Unique: cipLOEJnPe-XnciPl3jZxA-1 X-Mimecast-MFC-AGG-ID: cipLOEJnPe-XnciPl3jZxA_1739987306 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0C35E1800878; Wed, 19 Feb 2025 17:48:26 +0000 (UTC) Received: from bfoster.redhat.com (unknown [10.22.88.79]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 1EF461800265; Wed, 19 Feb 2025 17:48:24 +0000 (UTC) From: Brian Foster To: linux-fsdevel@vger.kernel.org Cc: linux-xfs@vger.kernel.org, Christoph Hellwig , "Darrick J . Wong" Subject: [PATCH v2 10/12] iomap: remove unnecessary advance from iomap_iter() Date: Wed, 19 Feb 2025 12:50:48 -0500 Message-ID: <20250219175050.83986-11-bfoster@redhat.com> In-Reply-To: <20250219175050.83986-1-bfoster@redhat.com> References: <20250219175050.83986-1-bfoster@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 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 Reviewed-by: "Darrick J. Wong" --- fs/iomap/iter.c | 39 +++++++++++++++------------------------ 1 file changed, 15 insertions(+), 24 deletions(-) diff --git a/fs/iomap/iter.c b/fs/iomap/iter.c index 0ebcabc7df52..e4dfe64029cc 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, @@ -89,27 +85,22 @@ 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) + if (iter->processed < 0) + ret = iter->processed; + else if (iter->len == 0 || (!advanced && !stale)) ret = 0; + else + ret = 1; iomap_iter_reset_iomap(iter); if (ret <= 0) return ret;