From: Herbert Xu <herbert@gondor.apana.org.au>
To: Alexander Aring <aahringo@redhat.com>
Cc: Network Development <netdev@vger.kernel.org>,
Pablo Neira Ayuso <pablo@netfilter.org>,
kadlec@netfilter.org, fw@strlen.de, gfs2@lists.linux.dev,
David Teigland <teigland@redhat.com>,
tgraf@suug.ch
Subject: Re: nft_rhash_walk, rhashtable and resize event
Date: Sat, 16 Sep 2023 11:37:51 +0800 [thread overview]
Message-ID: <ZQUjD0liUnH+ykKY@gondor.apana.org.au> (raw)
In-Reply-To: <CAK-6q+ghZRxrWQg3k0x1-SofoxfVfObJMg8wZ3UUMM4CU2oiWg@mail.gmail.com>
On Fri, Sep 15, 2023 at 10:05:06AM -0400, Alexander Aring wrote:
>
> My question is here? Is that allowed to do because a resize event may
> change the order how to iterate over a rhashtable.
Walking over an rhashtable should be a last resort. There is
no guarantee of stability.
If you skip entries after a resize then you may miss entries.
If you want a stable walk, allocate an extra 8 bytes and use
a linked list.
Cheers,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
next prev parent reply other threads:[~2023-09-16 3:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-15 14:05 nft_rhash_walk, rhashtable and resize event Alexander Aring
2023-09-16 3:37 ` Herbert Xu [this message]
2023-09-18 11:59 ` Pablo Neira Ayuso
2023-09-18 12:25 ` Herbert Xu
2023-09-18 12:38 ` Alexander Aring
2023-09-19 3:24 ` Herbert Xu
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