From patchwork Tue Oct 22 12:13:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13845660 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 BD3E619AD9B for ; Tue, 22 Oct 2024 12:14:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729599245; cv=none; b=ioAK2b1gRT6JdvzBtJrb7P4NmG+poi3hXUqeXtcGbKcpJIUJpjCRAvfl+MfFlvxWxAToO+4Q7Lo2yYU/CKaR/WMJU/ThVprfLaEApVeK94nlsbukk84gAOiqEJP0ROMMMx+bgqCsoXXMTt9mgyBUx8hghQNmm0ND99GKqQ/267M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729599245; c=relaxed/simple; bh=AaRepaf8xYjBUmYnBlGVUe3QxdUqaoTcI3WiZnKSkEI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kvFi2E/ZgBWbBR6iri1DBRpd30kt7eUCnPZMFbRx7LsYD5P5dad62/oET7+ZR4uIkQNgoCIHKaJAgMX3p40aCGQighs5bWn1k+dVlMob+myIwtCs2tUC4Ijx84zyIwDM7xbQo6HK8lqFAZk9R3XrWQ94Pu3q8Cz9wsK4hjtA5gs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=z+lkvTj2; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="z+lkvTj2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=xPxe9mIoVJyEi4Wa90Bzxq7uasxgy6x5YckTYolCQ1g=; b=z+lkvTj2dubFy/R3roUArRpB9v nXqMEY82v7FMaDe1Y8gxt3u1Uq0QUfg4sBqsGgljd1ZZqVZ55rb7x+5elfUudsHbPv9P7aJZvqCBQ EsZqhqBLqwJ4bjsex9m6C5KT1qnskPg24qSrOAlkbIi5ScXFq9Xaykyqy7ZAcd4joXEdZCukf9GuM RQB9geWHRc2DWQj4Lmom8hV5HDW+VOkI0G40T6IjTiepSuYBVHY+eEwAPDwniV7Q3UcbBXmdxDFKN M31HFjm1WcVehlGZ/hwfMidAXAfu/zlrxCkykdAHCdDfTnGropwT2G0iEkpmSpui86Vnu5W+LhcDY IY8b7G9w==; Received: from 2a02-8389-2341-5b80-1159-405c-1641-8dd9.cable.dynamic.v6.surfer.at ([2a02:8389:2341:5b80:1159:405c:1641:8dd9] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t3Dly-0000000Ao1o-39h0; Tue, 22 Oct 2024 12:14:03 +0000 From: Christoph Hellwig To: Carlos Maiolino Cc: "Darrick J. Wong" , linux-xfs@vger.kernel.org, syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com Subject: [PATCH 2/2] xfs: fix finding a last resort AG in xfs_filestream_pick_ag Date: Tue, 22 Oct 2024 14:13:38 +0200 Message-ID: <20241022121355.261836-3-hch@lst.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241022121355.261836-1-hch@lst.de> References: <20241022121355.261836-1-hch@lst.de> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html When the main loop in xfs_filestream_pick_ag fails to find a suitable AG it tries to just pick the online AG. But the loop for that uses args->pag as loop iterator while the later code expects pag to be set. Fix this by reusing the max_pag case for this last resort, and also add a check for impossible case of no AG just to make sure that the uninitialized pag doesn't even escape in theory. Reported-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig Tested-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com Reviewed-by: Darrick J. Wong --- fs/xfs/xfs_filestream.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c index f523027cc32586..ecf8a0f6c1362e 100644 --- a/fs/xfs/xfs_filestream.c +++ b/fs/xfs/xfs_filestream.c @@ -64,7 +64,7 @@ xfs_filestream_pick_ag( struct xfs_perag *pag; struct xfs_perag *max_pag = NULL; xfs_extlen_t minlen = *longest; - xfs_extlen_t free = 0, minfree, maxfree = 0; + xfs_extlen_t minfree, maxfree = 0; xfs_agnumber_t agno; bool first_pass = true; @@ -113,7 +113,6 @@ xfs_filestream_pick_ag( !(flags & XFS_PICK_USERDATA) || (flags & XFS_PICK_LOWSPACE))) { /* Break out, retaining the reference on the AG. */ - free = pag->pagf_freeblks; if (max_pag) xfs_perag_rele(max_pag); goto done; @@ -149,18 +148,19 @@ xfs_filestream_pick_ag( * filestream. It none suit, just use whatever AG we can grab. */ if (!max_pag) { - for_each_perag_wrap(args->mp, 0, start_agno, args->pag) + for_each_perag_wrap(args->mp, 0, start_agno, pag) { + max_pag = pag; break; - atomic_inc(&args->pag->pagf_fstrms); - *longest = 0; - } else { - pag = max_pag; - free = maxfree; - atomic_inc(&pag->pagf_fstrms); + } + /* Bail if there are no AGs at all to select from. */ + if (!max_pag) + return -ENOSPC; } + pag = max_pag; + atomic_inc(&pag->pagf_fstrms); done: - trace_xfs_filestream_pick(pag, pino, free); + trace_xfs_filestream_pick(pag, pino, pag->pagf_freeblks); args->pag = pag; return 0;