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From: Jeff King <peff@peff.net>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: "Duy Nguyen" <pclouds@gmail.com>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Johannes Sixt" <j6t@kdbg.org>,
	"Torsten Bögershausen" <tboegi@web.de>,
	git@vger.kernel.org
Subject: Re: [PATCH v4 19/32] commit_lock_file(): rollback lock file on failure to rename
Date: Wed, 10 Sep 2014 03:55:19 -0400	[thread overview]
Message-ID: <20140910075519.GA16413@peff.net> (raw)
In-Reply-To: <1409989846-22401-20-git-send-email-mhagger@alum.mit.edu>

On Sat, Sep 06, 2014 at 09:50:33AM +0200, Michael Haggerty wrote:

> If rename() fails, call rollback_lock_file() to delete the lock file
> (in case it is still present) and reset the filename field to the
> empty string so that the lockfile object is left in a valid state.

Unlike the previous patch, in this case the contents of the lockfile
_are_ defined. So in theory a caller could somehow retry.

I don't see any callers that want to do that, though (and besides, they
would not know if the error came from the close or the rename), so I
think we can consider that an uninteresting case until somebody
creates such a caller (at which point they can take responsibility for
extending the API).

BTW, while grepping for commit_lock_file calls, I notice we often commit
the shallow file without checking the return code. I'm not sure what we
should do in each case, but I imagine that calling die() is probably
better than continuing as if it succeeded. +cc Duy

-Peff

  reply	other threads:[~2014-09-10  7:55 UTC|newest]

Thread overview: 66+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-06  7:50 [PATCH v4 00/32] Lockfile correctness and refactoring Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 01/32] unable_to_lock_die(): rename function from unable_to_lock_index_die() Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 02/32] api-lockfile: expand the documentation Michael Haggerty
2014-09-09 22:40   ` Junio C Hamano
2014-09-06  7:50 ` [PATCH v4 03/32] rollback_lock_file(): do not clear filename redundantly Michael Haggerty
2014-09-11 19:13   ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 04/32] rollback_lock_file(): exit early if lock is not active Michael Haggerty
2014-09-11 19:13   ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 05/32] rollback_lock_file(): set fd to -1 Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 06/32] lockfile: unlock file if lockfile permissions cannot be adjusted Michael Haggerty
2014-09-09 22:39   ` Junio C Hamano
2014-09-12 11:03     ` Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 07/32] hold_lock_file_for_append(): release lock on errors Michael Haggerty
2014-09-09 22:41   ` Junio C Hamano
2014-09-12 11:04     ` Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 08/32] lock_file(): always add lock_file object to lock_file_list Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 09/32] lockfile.c: document the various states of lock_file objects Michael Haggerty
2014-09-11 19:57   ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 10/32] cache.h: define constants LOCK_SUFFIX and LOCK_SUFFIX_LEN Michael Haggerty
2014-09-11 22:15   ` Ronnie Sahlberg
2014-09-12 16:44     ` Michael Haggerty
2014-09-11 22:42   ` Ronnie Sahlberg
2014-09-12 17:13     ` Michael Haggerty
2014-09-12 17:32       ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 11/32] delete_ref_loose(): don't muck around in the lock_file's filename Michael Haggerty
2014-09-13  7:41   ` Johannes Sixt
2014-09-14  6:27     ` Michael Haggerty
2014-09-14  6:38       ` Michael Haggerty
2014-09-14 14:49         ` Johannes Sixt
2014-09-06  7:50 ` [PATCH v4 12/32] prepare_index(): declare return value to be (const char *) Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 13/32] write_packed_entry_fn(): convert cb_data into a (const int *) Michael Haggerty
2014-09-11 19:55   ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 14/32] lock_file(): exit early if lockfile cannot be opened Michael Haggerty
2014-09-11 22:49   ` Ronnie Sahlberg
2014-09-06  7:50 ` [PATCH v4 15/32] remove_lock_file(): call rollback_lock_file() Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 16/32] commit_lock_file(): inline temporary variable Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 17/32] commit_lock_file(): die() if called for unlocked lockfile object Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 18/32] commit_lock_file(): if close fails, roll back Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 19/32] commit_lock_file(): rollback lock file on failure to rename Michael Haggerty
2014-09-10  7:55   ` Jeff King [this message]
2014-09-10 12:55     ` Duy Nguyen
2014-09-06  7:50 ` [PATCH v4 20/32] api-lockfile: document edge cases Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 21/32] dump_marks(): remove a redundant call to rollback_lock_file() Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 22/32] git_config_set_multivar_in_file(): avoid " Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 23/32] lockfile: avoid transitory invalid states Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 24/32] struct lock_file: declare some fields volatile Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 25/32] try_merge_strategy(): remove redundant lock_file allocation Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 26/32] try_merge_strategy(): use a statically-allocated lock_file object Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 27/32] commit_lock_file(): use a strbuf to manage temporary space Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 28/32] Change lock_file::filename into a strbuf Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 29/32] resolve_symlink(): use a strbuf for internal scratch space Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 30/32] resolve_symlink(): take a strbuf parameter Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 31/32] trim_last_path_elm(): replace last_path_elm() Michael Haggerty
2014-09-06  7:50 ` [PATCH v4 32/32] Extract a function commit_lock_file_to() Michael Haggerty
2014-09-07 14:21 ` [PATCH v4 00/32] Lockfile correctness and refactoring Torsten Bögershausen
2014-09-12 12:50   ` Michael Haggerty
2014-09-08 22:35 ` Junio C Hamano
2014-09-10  8:13 ` Jeff King
2014-09-10 10:25   ` Duy Nguyen
2014-09-10 10:30     ` Jeff King
2014-09-10 16:51       ` Junio C Hamano
2014-09-10 19:11         ` Jeff King
2014-09-12 11:28           ` Michael Haggerty
2014-09-12 11:13         ` Michael Haggerty
2014-09-12 14:21   ` Michael Haggerty
2014-09-13 18:51     ` Jeff King

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