From: Jens Axboe <axboe@kernel.dk>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, torvalds@linux-foundation.org
Subject: Re: [PATCH 2/4] fs: add support for LOOKUP_NONBLOCK
Date: Tue, 15 Dec 2020 20:32:14 -0700 [thread overview]
Message-ID: <d20ac786-9bdc-524b-41c1-e14d9d2cd42d@kernel.dk> (raw)
In-Reply-To: <20201216024315.GJ3579531@ZenIV.linux.org.uk>
On 12/15/20 7:43 PM, Al Viro wrote:
> On Mon, Dec 14, 2020 at 12:13:22PM -0700, Jens Axboe wrote:
>> @@ -3140,6 +3149,12 @@ static const char *open_last_lookups(struct nameidata *nd,
>> return ERR_CAST(dentry);
>> if (likely(dentry))
>> goto finish_lookup;
>> + /*
>> + * We can't guarantee nonblocking semantics beyond this, if
>> + * the fast lookup fails.
>> + */
>> + if (nd->flags & LOOKUP_NONBLOCK)
>> + return ERR_PTR(-EAGAIN);
>>
>> BUG_ON(nd->flags & LOOKUP_RCU);
>
> That can't be right - we already must have removed LOOKUP_RCU here
> (see BUG_ON() right after that point). What is that test supposed
> to catch?
>
> What am I missing here?
Nothing I think, doesn't look like it's needed. If we don't return
a valid dentry under LOOKUP_RCU, we will indeed have unlazied at
this point. So this hunk can go.
--
Jens Axboe
next prev parent reply other threads:[~2020-12-16 3:32 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-14 19:13 [PATCHSET v3 0/4] fs: Support for LOOKUP_NONBLOCK / RESOLVE_NONBLOCK Jens Axboe
2020-12-14 19:13 ` [PATCH 1/4] fs: make unlazy_walk() error handling consistent Jens Axboe
2020-12-14 19:13 ` [PATCH 2/4] fs: add support for LOOKUP_NONBLOCK Jens Axboe
2020-12-15 12:24 ` Matthew Wilcox
2020-12-15 15:29 ` Jens Axboe
2020-12-15 15:33 ` Matthew Wilcox
2020-12-15 15:37 ` Jens Axboe
2020-12-15 16:08 ` Jens Axboe
2020-12-15 16:14 ` Jens Axboe
2020-12-15 18:29 ` Linus Torvalds
2020-12-15 18:44 ` Jens Axboe
2020-12-15 18:47 ` Linus Torvalds
2020-12-15 19:03 ` Jens Axboe
2020-12-15 19:32 ` Linus Torvalds
2020-12-15 19:38 ` Jens Axboe
2020-12-16 2:36 ` Al Viro
2020-12-16 3:30 ` Jens Axboe
2020-12-16 2:43 ` Al Viro
2020-12-16 3:32 ` Jens Axboe [this message]
2020-12-14 19:13 ` [PATCH 3/4] fs: expose LOOKUP_NONBLOCK through openat2() RESOLVE_NONBLOCK Jens Axboe
2020-12-15 22:25 ` Dave Chinner
2020-12-15 22:31 ` Linus Torvalds
2020-12-15 23:25 ` Jens Axboe
2020-12-16 2:37 ` Al Viro
2020-12-16 3:39 ` Linus Torvalds
2020-12-14 19:13 ` [PATCH 4/4] io_uring: enable LOOKUP_NONBLOCK path resolution for filename lookups Jens Axboe
2020-12-15 3:06 ` [PATCHSET v3 0/4] fs: Support for LOOKUP_NONBLOCK / RESOLVE_NONBLOCK Linus Torvalds
2020-12-15 3:18 ` Jens Axboe
2020-12-15 6:11 ` Al Viro
2020-12-15 15:29 ` Jens Axboe
2021-01-04 5:31 ` Al Viro
2021-01-04 14:43 ` Jens Axboe
2021-01-04 16:54 ` Al Viro
2021-01-04 17:03 ` Jens Axboe
[not found] ` <m1lfbrwrgq.fsf@fess.ebiederm.org>
2021-02-14 16:38 ` [PATCHSET v3 0/4] fs: Support for LOOKUP_NONBLOCK / RESOLVE_NONBLOCK (Insufficiently faking current?) Jens Axboe
2021-02-14 20:30 ` Linus Torvalds
2021-02-14 21:24 ` Al Viro
2021-02-15 18:07 ` Eric W. Biederman
2021-02-15 18:24 ` Jens Axboe
2021-02-15 21:09 ` Jens Axboe
2021-02-15 22:41 ` Eric W. Biederman
2021-02-16 2:41 ` Jens Axboe
2021-02-17 1:18 ` Jens Axboe
2021-02-17 1:26 ` Jens Axboe
2021-02-17 3:11 ` Jens Axboe
2021-02-15 17:56 ` Eric W. Biederman
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