From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DC8511AF0AE for ; Tue, 18 Feb 2025 20:10:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739909430; cv=none; b=dKKAM5CW97qtgQdxleyBrxToO9SCGzjsPJkhUPsP8qTbOgN9SYk5oMjalHiNdzIvm2gO3Iu2CJKRDiDkMOfDur2ZRJSFzZzz2HR4UhKLnL14C9FstK/B8YIuHLMGpWmME5V1hC6YJyx1GL/A4SZKuuhO5e/USG1MfOcNCpUCHWM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739909430; c=relaxed/simple; bh=kZShngn9jIbUZIaugn8hZzNQS9PC2VZpOMBNIyeWg5g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qIP1jdD9MEaffUGZmahISwKF8uZ/57mCCu7WaaNyF+3jD0D1YICA6fm30IBdp0dumytteZC1rgkFhANBifCKR9ED3zJjaHjYZY3FvlDId+K/TEGdi2+HsX0YGigV3VQty27KGdHlmFW30ojMehZQzOAQ6rg+4vdXDtj+ONbAh04= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JWiqJpF5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JWiqJpF5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59413C4CEE2; Tue, 18 Feb 2025 20:10:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739909430; bh=kZShngn9jIbUZIaugn8hZzNQS9PC2VZpOMBNIyeWg5g=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JWiqJpF5kok0WnaqvUloameKqtk1bJ1i/4URys5yWA78vHu4+YLmio0C9+2fkrwpu pnqka2JnBhpzS77DeTJseLkMAAdRgTSHQ2UASL5r1RNZpL6laAYW6CDZOCDKmtNh2a LORhzEg/yRCHn1+NaGtnAwJJoww8RpiHdh7swQdNkEat7koD9Q0C1UI4IjpB5Absgi bO+EfpDLd5fXBgNMVJOJaZuB+GC4nokPZJ6WgiJMBeh2wLvPvdJLHpyfVyEWD5ChWj xY/b45DuK1M8UWlIXcP3Ncop517zElIB4QT0mwREtwWLP+mUOo2D8eEXijfixgho0x 1RpaOcfuxydzQ== Date: Tue, 18 Feb 2025 12:10:29 -0800 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Carlos Maiolino , linux-xfs@vger.kernel.org Subject: Re: [PATCH 2/4] xfs: decouple buffer readahead from the normal buffer read path Message-ID: <20250218201029.GH21808@frogsfrogsfrogs> References: <20250217093207.3769550-1-hch@lst.de> <20250217093207.3769550-3-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250217093207.3769550-3-hch@lst.de> On Mon, Feb 17, 2025 at 10:31:27AM +0100, Christoph Hellwig wrote: > xfs_buf_readahead_map is the only caller of xfs_buf_read_map and thus > _xfs_buf_read that is not synchronous. Split it from xfs_buf_read_map > so that the asynchronous path is self-contained and the now purely > synchronous xfs_buf_read_map / _xfs_buf_read implementation can be > simplified. > > Signed-off-by: Christoph Hellwig Thanks for adding the ASSERT as a guardrail against misuse of xfs_buf_read. This appears to be a straightforward split, so Reviewed-by: "Darrick J. Wong" --D > --- > fs/xfs/xfs_buf.c | 41 ++++++++++++++++++++-------------------- > fs/xfs/xfs_buf.h | 2 +- > fs/xfs/xfs_log_recover.c | 2 +- > fs/xfs/xfs_trace.h | 1 + > 4 files changed, 23 insertions(+), 23 deletions(-) > > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index 050f2c2f6a40..52fb85c42e94 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -794,18 +794,13 @@ xfs_buf_get_map( > > int > _xfs_buf_read( > - struct xfs_buf *bp, > - xfs_buf_flags_t flags) > + struct xfs_buf *bp) > { > - ASSERT(!(flags & XBF_WRITE)); > ASSERT(bp->b_maps[0].bm_bn != XFS_BUF_DADDR_NULL); > > bp->b_flags &= ~(XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD | XBF_DONE); > - bp->b_flags |= flags & (XBF_READ | XBF_ASYNC | XBF_READ_AHEAD); > - > + bp->b_flags |= XBF_READ; > xfs_buf_submit(bp); > - if (flags & XBF_ASYNC) > - return 0; > return xfs_buf_iowait(bp); > } > > @@ -857,6 +852,8 @@ xfs_buf_read_map( > struct xfs_buf *bp; > int error; > > + ASSERT(!(flags & (XBF_WRITE | XBF_ASYNC | XBF_READ_AHEAD))); > + > flags |= XBF_READ; > *bpp = NULL; > > @@ -870,21 +867,11 @@ xfs_buf_read_map( > /* Initiate the buffer read and wait. */ > XFS_STATS_INC(target->bt_mount, xb_get_read); > bp->b_ops = ops; > - error = _xfs_buf_read(bp, flags); > - > - /* Readahead iodone already dropped the buffer, so exit. */ > - if (flags & XBF_ASYNC) > - return 0; > + error = _xfs_buf_read(bp); > } else { > /* Buffer already read; all we need to do is check it. */ > error = xfs_buf_reverify(bp, ops); > > - /* Readahead already finished; drop the buffer and exit. */ > - if (flags & XBF_ASYNC) { > - xfs_buf_relse(bp); > - return 0; > - } > - > /* We do not want read in the flags */ > bp->b_flags &= ~XBF_READ; > ASSERT(bp->b_ops != NULL || ops == NULL); > @@ -936,6 +923,7 @@ xfs_buf_readahead_map( > int nmaps, > const struct xfs_buf_ops *ops) > { > + const xfs_buf_flags_t flags = XBF_READ | XBF_ASYNC | XBF_READ_AHEAD; > struct xfs_buf *bp; > > /* > @@ -945,9 +933,20 @@ xfs_buf_readahead_map( > if (xfs_buftarg_is_mem(target)) > return; > > - xfs_buf_read_map(target, map, nmaps, > - XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD, &bp, ops, > - __this_address); > + if (xfs_buf_get_map(target, map, nmaps, flags | XBF_TRYLOCK, &bp)) > + return; > + trace_xfs_buf_readahead(bp, 0, _RET_IP_); > + > + if (bp->b_flags & XBF_DONE) { > + xfs_buf_reverify(bp, ops); > + xfs_buf_relse(bp); > + return; > + } > + XFS_STATS_INC(target->bt_mount, xb_get_read); > + bp->b_ops = ops; > + bp->b_flags &= ~(XBF_WRITE | XBF_DONE); > + bp->b_flags |= flags; > + xfs_buf_submit(bp); > } > > /* > diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h > index 3b4ed42e11c0..2e747555ad3f 100644 > --- a/fs/xfs/xfs_buf.h > +++ b/fs/xfs/xfs_buf.h > @@ -291,7 +291,7 @@ int xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, > int xfs_buf_read_uncached(struct xfs_buftarg *target, xfs_daddr_t daddr, > size_t numblks, xfs_buf_flags_t flags, struct xfs_buf **bpp, > const struct xfs_buf_ops *ops); > -int _xfs_buf_read(struct xfs_buf *bp, xfs_buf_flags_t flags); > +int _xfs_buf_read(struct xfs_buf *bp); > void xfs_buf_hold(struct xfs_buf *bp); > > /* Releasing Buffers */ > diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c > index b3c27dbccce8..2f76531842f8 100644 > --- a/fs/xfs/xfs_log_recover.c > +++ b/fs/xfs/xfs_log_recover.c > @@ -3380,7 +3380,7 @@ xlog_do_recover( > */ > xfs_buf_lock(bp); > xfs_buf_hold(bp); > - error = _xfs_buf_read(bp, XBF_READ); > + error = _xfs_buf_read(bp); > if (error) { > if (!xlog_is_shutdown(log)) { > xfs_buf_ioerror_alert(bp, __this_address); > diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h > index b29462363b81..bfc2f1249022 100644 > --- a/fs/xfs/xfs_trace.h > +++ b/fs/xfs/xfs_trace.h > @@ -593,6 +593,7 @@ DEFINE_EVENT(xfs_buf_flags_class, name, \ > DEFINE_BUF_FLAGS_EVENT(xfs_buf_find); > DEFINE_BUF_FLAGS_EVENT(xfs_buf_get); > DEFINE_BUF_FLAGS_EVENT(xfs_buf_read); > +DEFINE_BUF_FLAGS_EVENT(xfs_buf_readahead); > > TRACE_EVENT(xfs_buf_ioerror, > TP_PROTO(struct xfs_buf *bp, int error, xfs_failaddr_t caller_ip), > -- > 2.45.2 > >