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From: Al Viro <viro@zeniv.linux.org.uk>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	"zhengbin (A)" <zhengbin13@huawei.com>, Jan Kara <jack@suse.cz>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	"zhangyi (F)" <yi.zhang@huawei.com>,
	renxudong1@huawei.com, Hou Tao <houtao1@huawei.com>
Subject: Re: [PATCH] Re: Possible FS race condition between iterate_dir and d_alloc_parallel
Date: Wed, 25 Sep 2019 13:22:06 +0100	[thread overview]
Message-ID: <20190925122206.GJ26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAOQ4uxh-FH7JZP9fVqHXYJkbLA+NK6fX7HQex-XwY0Sha-R_kw@mail.gmail.com>

On Wed, Sep 25, 2019 at 02:59:47PM +0300, Amir Goldstein wrote:
> On Mon, Sep 23, 2019 at 5:34 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > FWIW, #next.dcache has the straight conversion to hlist.
> 
> Note that this:
> @@ -108,8 +108,8 @@ struct dentry {
>                 struct list_head d_lru;         /* LRU list */
>                 wait_queue_head_t *d_wait;      /* in-lookup ones only */
>         };
> -       struct list_head d_child;       /* child of parent list */
> -       struct list_head d_subdirs;     /* our children */
> +       struct hlist_node d_sibling;    /* child of parent list */
> +       struct hlist_head d_children;   /* our children */
> 
> Changes the 'standard' struct dentry size from 192 to 184.
> 
> Does that matter for cache line alignment?
> 
> Should struct dentry be ____cacheline_aligned?

*shrug*

DNAME_INLINE_LEN would need to be adjusted; it's just that I think
it would make a lot of sense to represent cursors not by dentries and
hang those on an additional hlist_head in dentry...

  reply	other threads:[~2019-09-25 12:22 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-03 14:44 Possible FS race condition between iterate_dir and d_alloc_parallel zhengbin (A)
2019-09-03 15:40 ` Al Viro
2019-09-03 15:41   ` Al Viro
2019-09-04  6:15     ` zhengbin (A)
2019-09-05 17:47       ` Al Viro
2019-09-06  0:55         ` Jun Li
2019-09-06  2:00           ` Al Viro
2019-09-06  2:32         ` zhengbin (A)
2019-09-09 14:10       ` zhengbin (A)
2019-09-09 14:59         ` Al Viro
2019-09-09 15:10           ` zhengbin (A)
     [not found]             ` <7e32cda5-dc89-719d-9651-cf2bd06ae728@huawei.com>
2019-09-10 21:53               ` Al Viro
2019-09-10 22:17                 ` Al Viro
2019-09-14 16:16                 ` [PATCH] " Al Viro
2019-09-14 16:49                   ` Linus Torvalds
2019-09-14 17:01                     ` Al Viro
2019-09-14 17:15                       ` Linus Torvalds
2019-09-14 20:04                         ` Al Viro
2019-09-14 22:57                           ` Linus Torvalds
2019-09-15  0:50                             ` Al Viro
2019-09-15  1:41                               ` Linus Torvalds
2019-09-15 16:02                                 ` Al Viro
2019-09-15 17:58                                   ` Linus Torvalds
2019-09-21 14:07                                     ` Al Viro
2019-09-21 16:21                                       ` Linus Torvalds
2019-09-21 17:18                                         ` Al Viro
2019-09-21 17:38                                           ` Linus Torvalds
2019-09-24  2:52                                       ` Al Viro
2019-09-24 13:30                                         ` Josef Bacik
2019-09-24 14:51                                           ` Al Viro
2019-09-24 15:01                                             ` Josef Bacik
2019-09-24 15:11                                               ` Al Viro
2019-09-24 15:26                                                 ` Josef Bacik
2019-09-24 16:33                                                   ` Al Viro
     [not found]                                         ` <CAHk-=wiJ1eY7y6r_cFNRPCqD+BJZS7eJeQFO6OrXxRFjDAipsQ@mail.gmail.com>
2019-09-29  5:29                                           ` Al Viro
2019-09-25 11:59                                       ` Amir Goldstein
2019-09-25 12:22                                         ` Al Viro [this message]
2019-09-25 12:34                                           ` Amir Goldstein
2019-09-22 21:29                     ` Al Viro
2019-09-23  3:32                       ` zhengbin (A)
2019-09-23  5:08                         ` Al Viro
     [not found]                   ` <20190916020434.tutzwipgs4f6o3di@inn2.lkp.intel.com>
2019-09-16  2:58                     ` 266a9a8b41: WARNING:possible_recursive_locking_detected Al Viro
2019-09-16  3:03                       ` Al Viro
2019-09-16  3:44                         ` Linus Torvalds
2019-09-16 17:16                           ` Al Viro
2019-09-16 17:29                             ` Al Viro
     [not found]                             ` <bd707e64-9650-e9ed-a820-e2cabd02eaf8@huawei.com>
2019-09-17 12:01                               ` Al Viro
2019-09-19  3:36                                 ` zhengbin (A)
2019-09-19  3:55                                   ` Al Viro

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