From patchwork Wed Jan 22 13:34:30 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 13947284 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 CECE6211A3B for ; Wed, 22 Jan 2025 13:32:28 +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=1737552750; cv=none; b=B3OO6Wvg7PmYUMupF6Hgus02hhscyExXRt19LVoAOwVkZmnA58pcOSQ+NKLR2m4Y4Zv/eHoSv76iAgrS5Tfj9WQwSUzpn7LFLs2ggUnLWc3UlCVO0cbwKb9qLpHNa/NLJ+FC9I2gGJxS8lNdATCpAT3fV3vXYKEmKWGjAkVs8Wk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737552750; c=relaxed/simple; bh=TOr5oWgkH7Q9YZBsYXY+h3c0MXVUiTU0kiQvMSdB7rw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=c9ix8pNrXhKrYLwT1a9dJMd+70kJotisuJNTnDx1DHKADoHhJ0Y8BbSiiOVk0sImLmyo8u/uN40q0l7DHeYjrCWULAx534G+Qhn7CfOsveyzsFGJvZuNUWwIwgGX9CxCwRFtc7o8d+o612oCWS+Ae1C5sxs4VwsmhDjjNAptWdI= 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=eQktUS+X; 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="eQktUS+X" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1737552747; 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=JEoq9O+sN6/C9lYpYN4gpK7SEnLTWIvXxcVRZYusifI=; b=eQktUS+XJUeDRZY/ce2g9FRapw4qXnS7stvrosEPP8C9Vom+FYmg5u7qY3VzyLKi+R8Vui TSaPVZAAUhmB0/GV42fn8GjdHTdHXg7mZHhjjQB8JzaBLqi6TWvfKmAf8t9jf34y0pDljx gcpL7e+pSrMfMK12qH70HCfqOZtUOkY= 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-550-M8mAoWQNNl2FFwpSe2brZw-1; Wed, 22 Jan 2025 08:32:24 -0500 X-MC-Unique: M8mAoWQNNl2FFwpSe2brZw-1 X-Mimecast-MFC-AGG-ID: M8mAoWQNNl2FFwpSe2brZw 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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7C7C119560B4; Wed, 22 Jan 2025 13:32:23 +0000 (UTC) Received: from bfoster.redhat.com (unknown [10.22.80.118]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id EE5F419560A7; Wed, 22 Jan 2025 13:32:22 +0000 (UTC) From: Brian Foster To: linux-fsdevel@vger.kernel.org Cc: linux-xfs@vger.kernel.org Subject: [PATCH v2 3/7] iomap: refactor iter and advance continuation logic Date: Wed, 22 Jan 2025 08:34:30 -0500 Message-ID: <20250122133434.535192-4-bfoster@redhat.com> In-Reply-To: <20250122133434.535192-1-bfoster@redhat.com> References: <20250122133434.535192-1-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 3.0 on 10.30.177.12 In preparation for future changes and more generic use of iomap_iter_advance(), lift the high level iter continuation logic out of iomap_iter_advance() into the caller. Also add some comments and rework iomap_iter() to jump straight to ->iomap_begin() on the first iteration. Signed-off-by: Brian Foster --- fs/iomap/iter.c | 54 +++++++++++++++++++++++-------------------- include/linux/iomap.h | 1 + 2 files changed, 30 insertions(+), 25 deletions(-) diff --git a/fs/iomap/iter.c b/fs/iomap/iter.c index 731ea7267f27..260ec702ddd5 100644 --- a/fs/iomap/iter.c +++ b/fs/iomap/iter.c @@ -15,31 +15,19 @@ static inline void iomap_iter_reset_iomap(struct iomap_iter *iter) } /* - * Advance to the next range we need to map. - * - * If the iomap is marked IOMAP_F_STALE, it means the existing map was not fully - * processed - it was aborted because the extent the iomap spanned may have been - * changed during the operation. In this case, the iteration behaviour is to - * remap the unprocessed range of the iter, and that means we may need to remap - * even when we've made no progress (i.e. count = 0). Hence the "finished - * iterating" case needs to distinguish between (count = 0) meaning we are done - * and (count = 0 && stale) meaning we need to remap the entire remaining range. + * Advance the current iterator position and return the length remaining for the + * current mapping. */ -static inline int iomap_iter_advance(struct iomap_iter *iter, s64 count) +s64 iomap_iter_advance(struct iomap_iter *iter, s64 count) { - bool stale = iter->iomap.flags & IOMAP_F_STALE; - int ret = 1; - if (count < 0) return count; if (WARN_ON_ONCE(count > iomap_length(iter))) return -EIO; iter->pos += count; iter->len -= count; - if (!iter->len || (!count && !stale)) - ret = 0; - return ret; + return iomap_length(iter); } static inline void iomap_iter_done(struct iomap_iter *iter) @@ -71,9 +59,15 @@ static inline void iomap_iter_done(struct iomap_iter *iter) */ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) { - int ret; + s64 ret; + bool stale = iter->iomap.flags & IOMAP_F_STALE; - if (iter->iomap.length && ops->iomap_end) { + if (!iter->iomap.length) { + trace_iomap_iter(iter, ops, _RET_IP_); + goto begin; + } + + if (ops->iomap_end) { ret = ops->iomap_end(iter->inode, iter->pos, iomap_length(iter), iter->processed > 0 ? iter->processed : 0, iter->flags, &iter->iomap); @@ -81,15 +75,25 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops) return ret; } - /* advance and clear state from the previous iteration */ + /* + * Advance the iter and clear state from the previous iteration. The + * remaining length of the previous iteration should be zero by this + * point, so use iter->len to determine whether to continue onto the + * next mapping. Explicitly terminate in the case where 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. + */ trace_iomap_iter(iter, ops, _RET_IP_); - if (iter->iomap.length) { - ret = iomap_iter_advance(iter, iter->processed); - iomap_iter_reset_iomap(iter); - if (ret <= 0) - return ret; - } + ret = iomap_iter_advance(iter, iter->processed); + if (!ret) + ret = iter->len; + if (ret > 0 && !iter->processed && !stale) + ret = 0; + iomap_iter_reset_iomap(iter); + if (ret <= 0) + return ret; +begin: ret = ops->iomap_begin(iter->inode, iter->pos, iter->len, iter->flags, &iter->iomap, &iter->srcmap); if (ret < 0) diff --git a/include/linux/iomap.h b/include/linux/iomap.h index b6f7d96156f2..88bde0259035 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -229,6 +229,7 @@ struct iomap_iter { }; int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops); +s64 iomap_iter_advance(struct iomap_iter *iter, s64 count); static inline u64 iomap_length_trim(const struct iomap_iter *iter, loff_t pos, u64 len)