Git Mailing List Archive on lore.kernel.org
 help / color / Atom feed
From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Johannes Sixt <j6t@kdbg.org>
Cc: git@vger.kernel.org, tytso@mit.edu,
	Junio C Hamano <gitster@pobox.com>,
	Christoph Hellwig <hch@lst.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [RFC PATCH 1/2] sha1-file: fsync() loose dir entry when core.fsyncObjectFiles
Date: Tue, 22 Sep 2020 10:24:51 +0200
Message-ID: <87a6xii5gs.fsf@evledraar.gmail.com> (raw)
In-Reply-To: <64358b70-4fff-5dc8-6e63-2fc916bea6af@kdbg.org>


On Thu, Sep 17 2020, Johannes Sixt wrote:

> Am 17.09.20 um 13:28 schrieb Ævar Arnfjörð Bjarmason:
>> Change the behavior of core.fsyncObjectFiles to also sync the
>> directory entry. I don't have a case where this broke, just going by
>> paranoia and the fsync(2) manual page's guarantees about its behavior.
>> 
>> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
>> ---
>>  sha1-file.c | 19 ++++++++++++++-----
>>  1 file changed, 14 insertions(+), 5 deletions(-)
>> 
>> diff --git a/sha1-file.c b/sha1-file.c
>> index dd65bd5c68..d286346921 100644
>> --- a/sha1-file.c
>> +++ b/sha1-file.c
>> @@ -1784,10 +1784,14 @@ int hash_object_file(const struct git_hash_algo *algo, const void *buf,
>>  }
>>  
>>  /* Finalize a file on disk, and close it. */
>> -static void close_loose_object(int fd)
>> +static void close_loose_object(int fd, const struct strbuf *dirname)
>>  {
>> -	if (fsync_object_files)
>> +	int dirfd;
>> +	if (fsync_object_files) {
>>  		fsync_or_die(fd, "loose object file");
>> +		dirfd = xopen(dirname->buf, O_RDONLY);
>> +		fsync_or_die(dirfd, "loose object directory");
>
> Did you have the opportunity to verify that this works on Windows?
> Opening a directory with open(2), I mean: It's disallowed according to
> the docs:
> https://docs.microsoft.com/en-us/cpp/c-runtime-library/reference/open-wopen?view=vs-2019#return-value

I did not, just did a quick hack for an RFC discussion (didn't even
close() that fd), but if I pursue this I'll do it properly.

Doing some research on it now reveals that we should probably have some
Windows-specific code here, e.g. browsing GNUlib's source code reveals
that it uses FlushFileBuffers(), and that code itself is taken from
sqlite. SQLite also has special-case code for some Unix warts,
e.g. OSX's and AIX's special fsync behaviors in its src/os_unix.c

>> +	}
>>  	if (close(fd) != 0)
>>  		die_errno(_("error when closing loose object file"));
>>  }
>
> -- Hannes


  reply index

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-17 18:48 [PATCH] enable core.fsyncObjectFiles by default Christoph Hellwig
2018-01-17 19:04 ` Junio C Hamano
2018-01-17 19:35   ` Christoph Hellwig
2018-01-17 20:05     ` Andreas Schwab
2018-01-17 19:37   ` Matthew Wilcox
2018-01-17 19:42     ` Christoph Hellwig
2018-01-17 21:44   ` Ævar Arnfjörð Bjarmason
2018-01-17 22:07     ` Linus Torvalds
2018-01-17 22:25       ` Linus Torvalds
2018-01-17 23:16       ` Ævar Arnfjörð Bjarmason
2018-01-17 23:42         ` Linus Torvalds
2018-01-17 23:52       ` Theodore Ts'o
2018-01-17 23:57         ` Linus Torvalds
2018-01-18 16:27           ` Christoph Hellwig
2018-01-19 19:08             ` Junio C Hamano
2018-01-20 22:14               ` Theodore Ts'o
2018-01-20 22:27                 ` Junio C Hamano
2018-01-22 15:09                   ` Ævar Arnfjörð Bjarmason
2018-01-22 18:09                     ` Theodore Ts'o
2018-01-23  0:47                       ` Jeff King
2018-01-23  5:45                         ` Theodore Ts'o
2018-01-23 16:17                           ` Jeff King
2018-01-23  0:25                     ` Jeff King
2018-01-21 21:32             ` Chris Mason
2020-09-17 11:06         ` Ævar Arnfjörð Bjarmason
2020-09-17 11:28           ` [RFC PATCH 0/2] should core.fsyncObjectFiles fsync the dir entry + docs Ævar Arnfjörð Bjarmason
2020-09-17 11:28           ` [RFC PATCH 1/2] sha1-file: fsync() loose dir entry when core.fsyncObjectFiles Ævar Arnfjörð Bjarmason
2020-09-17 13:16             ` Jeff King
2020-09-17 15:09               ` Christoph Hellwig
2020-09-17 14:09             ` Christoph Hellwig
2020-09-17 14:55               ` Jeff King
2020-09-17 14:56                 ` Christoph Hellwig
2020-09-17 15:37                   ` Junio C Hamano
2020-09-17 17:12                     ` Jeff King
2020-09-17 20:37                       ` Taylor Blau
2020-09-22 10:42               ` Ævar Arnfjörð Bjarmason
2020-09-17 20:21             ` Johannes Sixt
2020-09-22  8:24               ` Ævar Arnfjörð Bjarmason [this message]
2020-11-19 11:38                 ` Johannes Schindelin
2020-09-17 11:28           ` [RFC PATCH 2/2] core.fsyncObjectFiles: make the docs less flippant Ævar Arnfjörð Bjarmason
2020-09-17 14:12             ` Christoph Hellwig
2020-09-17 15:43             ` Junio C Hamano
2020-09-17 20:15               ` Johannes Sixt
2020-10-08  8:13               ` Johannes Schindelin
2020-10-08 15:57                 ` Ævar Arnfjörð Bjarmason
2020-10-08 18:53                   ` Junio C Hamano
2020-10-09 10:44                   ` Johannes Schindelin
2020-09-17 19:21             ` Marc Branchaud
2020-09-17 14:14           ` [PATCH] enable core.fsyncObjectFiles by default Christoph Hellwig
2020-09-17 15:30           ` Junio C Hamano
2018-01-17 20:55 ` Jeff King
2018-01-17 21:10   ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87a6xii5gs.fsf@evledraar.gmail.com \
    --to=avarab@gmail.com \
    --cc=git@vger.kernel.org \
    --cc=gitster@pobox.com \
    --cc=hch@lst.de \
    --cc=j6t@kdbg.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=tytso@mit.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Git Mailing List Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/git/0 git/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 git git/ https://lore.kernel.org/git \
		git@vger.kernel.org
	public-inbox-index git

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.git


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git