From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: Michael Haggerty <mhagger@alum•mit.edu>, git@vger•kernel.org
Subject: Re: [PATCH 07/22] lock_file(): always add lock_file object to lock_file_list
Date: Wed, 02 Apr 2014 10:01:59 -0700 [thread overview]
Message-ID: <xmqqppkzwtq0.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <20140401201659.GE21715@sigill.intra.peff.net> (Jeff King's message of "Tue, 1 Apr 2014 16:16:59 -0400")
Jeff King <peff@peff•net> writes:
> So for a moment, lk->filename contains the name of the valuable file we
> are locking. If we get a signal at that moment, do we accidentally
> delete it in remove_lock_file?
>
> I think the answer is "no", because we check lk->owner before deleting,
> which will not match our pid (it should generally be zero due to xcalloc
> or static initialization, though perhaps we should clear it here).
That "generally be zero" no longer holds since 2/22, no?
> But that makes me wonder about the case of a reused lock. It will have
> lk->owner set from a previous invocation, and would potentially suffer
> from this problem. In other words, I think the change you are
> introducing does not have the problem, but the existing code does. :-/
Yes, I tend to agree.
> I didn't reproduce it experimentally, though. We should be able to just
>
> lk->owner = 0;
>
> before the initial strcpy to fix it, I would think.
>
> -Peff
next prev parent reply other threads:[~2014-04-03 10:01 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-01 15:58 [PATCH 00/22] Lockfile refactoring and pre-activation Michael Haggerty
2014-04-01 15:58 ` [PATCH 01/22] t3204: test deleting references when lock files already exist Michael Haggerty
2014-04-01 19:53 ` Jeff King
2014-04-02 10:28 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 02/22] try_merge_strategy(): remove redundant lock_file allocation Michael Haggerty
2014-04-01 19:56 ` Jeff King
2014-04-02 10:53 ` Michael Haggerty
2014-04-02 16:53 ` Junio C Hamano
2014-04-03 12:43 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 03/22] rollback_lock_file(): do not clear filename redundantly Michael Haggerty
2014-04-01 15:58 ` [PATCH 04/22] rollback_lock_file(): set fd to -1 Michael Haggerty
2014-04-01 19:59 ` Jeff King
2014-04-02 16:58 ` Junio C Hamano
2014-04-06 21:45 ` Michael Haggerty
2014-04-07 16:37 ` Junio C Hamano
2014-04-01 15:58 ` [PATCH 05/22] lockfile: unlock file if lockfile permissions cannot be adjusted Michael Haggerty
2014-04-01 20:02 ` Jeff King
2014-04-01 20:05 ` Jeff King
2014-04-02 6:47 ` Torsten Bögershausen
2014-04-06 22:02 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 06/22] hold_lock_file_for_append(): release lock on errors Michael Haggerty
2014-04-01 15:58 ` [PATCH 07/22] lock_file(): always add lock_file object to lock_file_list Michael Haggerty
2014-04-01 20:16 ` Jeff King
2014-04-02 17:01 ` Junio C Hamano [this message]
2014-04-06 21:54 ` Michael Haggerty
2014-04-07 9:36 ` Jeff King
2014-04-01 15:58 ` [PATCH 08/22] struct lock_file: replace on_list field with flags field Michael Haggerty
2014-04-01 15:58 ` [PATCH 09/22] api-lockfile: expand the documentation Michael Haggerty
2014-04-01 20:19 ` Jeff King
2014-04-02 11:36 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 10/22] lockfile.c: document the various states of lock_file objects Michael Haggerty
2014-04-01 15:58 ` [PATCH 11/22] lockfile: define a constant LOCK_SUFFIX_LEN Michael Haggerty
2014-04-02 17:27 ` Junio C Hamano
2014-04-01 15:58 ` [PATCH 12/22] delete_ref_loose(): don't muck around in the lock_file's filename Michael Haggerty
2014-04-01 20:21 ` Jeff King
2014-04-02 11:50 ` Michael Haggerty
2014-04-02 6:52 ` Torsten Bögershausen
2014-04-02 6:55 ` Jeff King
2014-04-01 15:58 ` [PATCH 13/22] config: change write_error() to take a (struct lock_file *) argument Michael Haggerty
2014-04-02 6:58 ` Torsten Bögershausen
2014-04-06 22:04 ` Michael Haggerty
2014-04-02 17:29 ` Junio C Hamano
2014-04-01 15:58 ` [PATCH 14/22] lockfile: use strbufs when handling (most) paths Michael Haggerty
2014-04-01 20:28 ` Jeff King
2014-04-02 17:16 ` Junio C Hamano
2014-04-01 15:58 ` [PATCH 15/22] resolve_symlink(): use a strbuf internally Michael Haggerty
2014-04-01 15:58 ` [PATCH 16/22] commit_lock_file(): don't work with a fixed-length buffer Michael Haggerty
2014-04-01 15:58 ` [PATCH 17/22] lock_file(): exit early if lockfile cannot be opened Michael Haggerty
2014-04-01 15:58 ` [PATCH 18/22] lockfile: also keep track of the filename of the file being locked Michael Haggerty
2014-04-02 17:19 ` Junio C Hamano
2014-04-06 22:05 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 19/22] struct lock_file: rename lock_filename field to staging_filename Michael Haggerty
2014-04-01 15:58 ` [PATCH 20/22] remove_lock_file(): call rollback_lock_file() Michael Haggerty
2014-04-01 15:58 ` [PATCH 21/22] lockfile: extract a function reset_lock_file() Michael Haggerty
2014-04-02 7:06 ` Eric Sunshine
2014-04-02 13:37 ` Michael Haggerty
2014-04-01 15:58 ` [PATCH 22/22] lockfile: allow new file contents to be written while retaining lock Michael Haggerty
2014-04-01 20:39 ` Jeff King
2014-04-02 7:20 ` Eric Sunshine
2014-04-02 17:26 ` Junio C Hamano
2014-04-01 20:44 ` [PATCH 00/22] Lockfile refactoring and pre-activation Jeff King
2014-04-03 11:42 ` Michael Haggerty
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