All of lore.kernel.org
 help / color / mirror / Atom feed
From: Vlad Buslov <vladbu@mellanox.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Vlad Buslov <vladbu@mellanox.com>,
	Matthew Wilcox <willy@infradead.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH 29/38] cls_flower: Convert handle_idr to XArray
Date: Mon, 26 Aug 2019 10:11:49 +0000	[thread overview]
Message-ID: <vbfk1b08cd9.fsf@mellanox.com> (raw)
In-Reply-To: <CAM_iQpXXKwKUhzU1wwXrXqwXSEq-OJ4diBhSuR04kitLKs=g0g@mail.gmail.com>


On Sun 25 Aug 2019 at 21:32, Cong Wang <xiyou.wangcong@gmail.com> wrote:
> On Wed, Aug 21, 2019 at 11:27 AM Vlad Buslov <vladbu@mellanox.com> wrote:
>> At first I was confused why you bring up rtnl lock in commit message
>> (flower classifier has 'unlocked' flag set and can't rely on it anymore)
>> but looking at the code I see that we lost rcu read lock here in commit
>> d39d714969cd ("idr: introduce idr_for_each_entry_continue_ul()") and you
>> are correctly bringing it back. Adding Cong to advise if it is okay to
>> wait for this patch to be accepted or we need to proceed with fixing the
>> missing RCU lock as a standalone patch.
>
> Hmm? Isn't ->walk() still called with RTNL lock? tcf_chain_dump()
> calls __tcf_get_next_proto() which asserts RTNL.
>
> So why does it still need RCU read lock when having RTNL?

Individual filters can be deleted without obtaining rtnl lock. And
without rcu read lock, f can be deallocated in fl_walk() main loop
before refcount_inc_not_zero() obtains reference to it.

  reply	other threads:[~2019-08-26 10:11 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-20 22:32 [PATCH 00/38] Convert networking to use the XArray Matthew Wilcox
2019-08-20 22:32 ` [PATCH 01/38] mlx4: Convert cq_table->tree to XArray Matthew Wilcox
2019-08-20 22:32 ` [PATCH 02/38] mlx4: Convert srq_table->tree " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 03/38] mlx4: Convert qp_table_tree " Matthew Wilcox
2019-08-27 19:18   ` Saeed Mahameed
2019-08-20 22:32 ` [PATCH 04/38] mlx5: Convert cq_table " Matthew Wilcox
2019-08-27 19:22   ` Saeed Mahameed
2019-08-20 22:32 ` [PATCH 05/38] mlx5: Convert mlx5_qp_table " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 06/38] mlx5: Convert counters_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 07/38] mlx5: Convert fpga IDRs " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 08/38] nfp: Convert " Matthew Wilcox
2019-08-21  3:59   ` Jakub Kicinski
2019-08-20 22:32 ` [PATCH 09/38] ath10k: Convert pending_tx " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 10/38] ath10k: Convert mgmt_pending_tx IDR " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 11/38] mt76: Convert token " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 12/38] mwifiex: Convert ack_status_frames " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 13/38] ppp: Convert units_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 14/38] tap: Convert minor_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 15/38] nfp: Convert internal ports " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 16/38] qrtr: Convert qrtr_nodes " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 17/38] qrtr: Convert qrtr_ports " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 18/38] rxrpc: Convert " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 19/38] 9p: Convert reqs IDR " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 20/38] 9p: Convert fids " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 21/38] 9p: Move lock from client to trans_fd Matthew Wilcox
2019-08-20 22:32 ` [PATCH 22/38] sctp: Convert sctp_assocs_id to XArray Matthew Wilcox
2019-08-20 22:32 ` [PATCH 23/38] cls_api: Convert tcf_net " Matthew Wilcox
2019-08-20 23:57   ` David Miller
2019-08-21  0:52     ` Matthew Wilcox
2019-08-20 22:32 ` [PATCH 24/38] cls_u32: Convert tc_u_common->handle_idr " Matthew Wilcox
2019-08-21 21:13   ` Jakub Kicinski
2019-08-21 21:25     ` Matthew Wilcox
2019-08-21 21:38       ` Jakub Kicinski
2019-08-20 22:32 ` [PATCH 25/38] cls_u32: Convert tc_u_hnode->handle_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 26/38] cls_bpf: Convert handle_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 27/38] cls_bpf: Remove list of programs Matthew Wilcox
2019-08-20 22:32 ` [PATCH 28/38] cls_bpf: Use XArray marks to accelerate re-offload Matthew Wilcox
2019-08-20 22:32 ` [PATCH 29/38] cls_flower: Convert handle_idr to XArray Matthew Wilcox
2019-08-20 23:58   ` David Miller
2019-08-21  0:50     ` Matthew Wilcox
2019-08-21 18:27   ` Vlad Buslov
2019-08-25 18:32     ` Cong Wang
2019-08-26 10:11       ` Vlad Buslov [this message]
2019-08-20 22:32 ` [PATCH 30/38] cls_flower: Use XArray list of filters in fl_walk Matthew Wilcox
2019-08-21 18:32   ` Vlad Buslov
2019-08-20 22:32 ` [PATCH 31/38] cls_flower: Use XArray marks instead of separate list Matthew Wilcox
2019-08-21 19:12   ` Vlad Buslov
2019-08-20 22:32 ` [PATCH 32/38] cls_basic: Convert handle_idr to XArray Matthew Wilcox
2019-08-20 22:32 ` [PATCH 33/38] act_api: Convert action_idr " Matthew Wilcox
2019-08-21 19:41   ` Vlad Buslov
2019-08-21 20:35     ` Matthew Wilcox
2019-08-20 22:32 ` [PATCH 34/38] net_namespace: Convert netns_ids " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 35/38] tipc: Convert conn_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 36/38] netlink: Convert genl_fam_idr " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 37/38] mac80211: Convert ack_status_frames " Matthew Wilcox
2019-08-20 22:32 ` [PATCH 38/38] mac80211: Convert function_inst_ids " Matthew Wilcox

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=vbfk1b08cd9.fsf@mellanox.com \
    --to=vladbu@mellanox.com \
    --cc=netdev@vger.kernel.org \
    --cc=willy@infradead.org \
    --cc=xiyou.wangcong@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.