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@xxxxxxxxx>
>> ---
>> 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
