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From: hooanon05g@gmail.com
To: "NeilBrown" <neilb@suse.de>
Cc: trond.myklebust@hammerspace.com, linux-nfs@vger.kernel.org
Subject: Re: NFS, two d_delete() calls in nfs_unlink()
Date: Thu, 18 Aug 2022 12:31:31 +0900	[thread overview]
Message-ID: <9451.1660793491@jrobl> (raw)
In-Reply-To: <166079133167.5425.16635199337074058478@noble.neil.brown.name>

"NeilBrown":
> Thanks for the report.
> This possibility of calling d_delete() twice has been present
> since  9019fb391de0 in v5.16.

I don't think 9019fb391de0 is a problem.
Before v6.0-rc1, the target dentry was unhashed by __d_drop() call in
nfs_unlink(), and nfs_dentry_handle_enoent() skipped calling d_delete()
by simple_positive(). d_delete() was called only once via
nfs_dentry_remove_handle_error().

In v6.0-rc1, the dentry is not unhashed and nfs_dentry_handle_enoent()
doesn't skip calling d_delete().


> How did you discover this bug, and why do you think my patch
> caused it?

I met this problem during a stress test aiming a filesystem I am
developing.
And I think unhashing causes nfs_dentry_handle_enoent() to call
d_delete().


J. R. Okajima

  reply	other threads:[~2022-08-18  3:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-17  9:29 NFS, two d_delete() calls in nfs_unlink() J. R. Okajima
2022-08-18  2:55 ` NeilBrown
2022-08-18  3:31   ` hooanon05g [this message]
2022-08-18 18:38     ` Olga Kornievskaia
2022-08-18 23:05     ` NeilBrown
2022-08-18 23:23       ` Trond Myklebust

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