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From: Al Viro <viro@zeniv.linux.org.uk>
To: "zhengbin (A)" <zhengbin13@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	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: Mon, 23 Sep 2019 06:08:58 +0100	[thread overview]
Message-ID: <20190923050858.GB26530@ZenIV.linux.org.uk> (raw)
In-Reply-To: <0848b6c7-386c-21fb-233f-be8d9965fbf7@huawei.com>

On Mon, Sep 23, 2019 at 11:32:43AM +0800, zhengbin (A) wrote:

> 
> Is it possible to trigger ABBA deadlock? In next_positive, the lock order is (parent, dentry),
> 
> while in dput, the lock order is (dentry, parent). Cause we use spin_trylock(parent), so the ABBA deadlock will not open.
> 
> dput
> 
>     fast_dput
> 
>        spin_lock(&dentry->d_lock)
> 
>    dentry_kill
> 
>        spin_trylock(&parent->d_lock))
> 
> Is there any other scene like dput, but do not use spin_trylock? I am looking for the code, till now do not find this

There should be none.  The order is parent, then child.  And
all changes of the tree topology are serialized by rename_lock.

  reply	other threads:[~2019-09-23  5:09 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
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 [this message]
     [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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