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 383FE1FB8B1; Wed, 6 Nov 2024 12:54:30 +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=1730897670; cv=none; b=XvsaFvZuTq699xidQuZUwMESzKMQHUlmBPU+CTGO3c3aua1DBQlmu1k4l+PzBf1hsNSOZDFgwEm4znSVTE4dVZGsT5nOokm3VhRnQffPHxuHms6zYF1srZg288YgyyWAQvbMA7UXR7i0vEOSAmxof4KrPmiF8FDFw4wT+WRYwGA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730897670; c=relaxed/simple; bh=ncbGO4h92UUkd2BMrrJzJVcJ4lBFbkk3nXlfvy6fMW8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kFp2b/dxshMj4nuiSFa0+cijIIyrfp6pW7+6d5yjDB6uvXz4UIhaL+ra6MM1YaLPEPYUKTHvthOzLttdlXBQGd1ZHc2HA6XXmS8oNQ4kSwRxp0KVyimZ1QBgusBtmr/OPFyjf+57Odwj39nuRLpzDgJZs7vEuzEKAjJlpUCHW4Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IYCqEVGw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="IYCqEVGw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B14BDC4CECD; Wed, 6 Nov 2024 12:54:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730897670; bh=ncbGO4h92UUkd2BMrrJzJVcJ4lBFbkk3nXlfvy6fMW8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IYCqEVGwFlTJidr/hALagouO7M4itkUnLL/BTD4jRXigZc4SL1Vzax/NGWOZVPpPp 1YyXyptp/1np5ABssedOPqhPDqR6pdnFCAfD9oWoFglxntxGDC2ImYyLkikV93AVI/ zM6K9NVKkIlC6rpXVUNeT3qMFQtPqsWi2qOWkjEU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com, Christoph Hellwig , "Darrick J. Wong" , Carlos Maiolino , Sasha Levin Subject: [PATCH 6.6 131/151] xfs: fix finding a last resort AG in xfs_filestream_pick_ag Date: Wed, 6 Nov 2024 13:05:19 +0100 Message-ID: <20241106120312.465329693@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120308.841299741@linuxfoundation.org> References: <20241106120308.841299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoph Hellwig [ Upstream commit dc60992ce76fbc2f71c2674f435ff6bde2108028 ] 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 Fixes: f8f1ed1ab3baba ("xfs: return a referenced perag from filestreams allocator") Cc: # v6.3 Reviewed-by: Darrick J. Wong Signed-off-by: Carlos Maiolino Signed-off-by: Sasha Levin --- fs/xfs/xfs_filestream.c | 23 ++++++++++++----------- fs/xfs/xfs_trace.h | 15 +++++---------- 2 files changed, 17 insertions(+), 21 deletions(-) diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c index 2fc98d3137086..f62b023f274e9 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; int err; @@ -107,7 +107,6 @@ xfs_filestream_pick_ag( !(flags & XFS_PICK_USERDATA) || (flags & XFS_PICK_LOWSPACE))) { /* Break out, retaining the reference on the AG. */ - free = pag->pagf_freeblks; break; } } @@ -150,23 +149,25 @@ xfs_filestream_pick_ag( * 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); } else if (max_pag) { xfs_perag_rele(max_pag); } - trace_xfs_filestream_pick(pag, pino, free); + trace_xfs_filestream_pick(pag, pino); args->pag = pag; return 0; - } static struct xfs_inode * diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 3926cf7f2a6ed..d562028281f5c 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -672,8 +672,8 @@ DEFINE_FILESTREAM_EVENT(xfs_filestream_lookup); DEFINE_FILESTREAM_EVENT(xfs_filestream_scan); TRACE_EVENT(xfs_filestream_pick, - TP_PROTO(struct xfs_perag *pag, xfs_ino_t ino, xfs_extlen_t free), - TP_ARGS(pag, ino, free), + TP_PROTO(struct xfs_perag *pag, xfs_ino_t ino), + TP_ARGS(pag, ino), TP_STRUCT__entry( __field(dev_t, dev) __field(xfs_ino_t, ino) @@ -684,14 +684,9 @@ TRACE_EVENT(xfs_filestream_pick, TP_fast_assign( __entry->dev = pag->pag_mount->m_super->s_dev; __entry->ino = ino; - if (pag) { - __entry->agno = pag->pag_agno; - __entry->streams = atomic_read(&pag->pagf_fstrms); - } else { - __entry->agno = NULLAGNUMBER; - __entry->streams = 0; - } - __entry->free = free; + __entry->agno = pag->pag_agno; + __entry->streams = atomic_read(&pag->pagf_fstrms); + __entry->free = pag->pagf_freeblks; ), TP_printk("dev %d:%d ino 0x%llx agno 0x%x streams %d free %d", MAJOR(__entry->dev), MINOR(__entry->dev), -- 2.43.0