From: René Scharfe Date: Fri, 10 Jun 2022 21:10:17 GMT Subject: Re: [PATCH v14 2/7] object-file.c: do fsync() and close() before post-write die() Message-ID: <0b9bc499-18c7-e8ab-5c89-f9e1a98685bc@web.de> In-Reply-To: Am 10.06.22 um 16:46 schrieb Han Xin: > From: Ævar Arnfjörð Bjarmason > > Change write_loose_object() to do an fsync() and close() before the > oideq() sanity check at the end. This change re-joins code that was > split up by the die() sanity check added in 748af44c63e (sha1_file: be > paranoid when creating loose objects, 2010-02-21). > > I don't think that this change matters in itself, if we called die() > it was possible that our data wouldn't fully make it to disk, but in > any case we were writing data that we'd consider corrupted. It's > possible that a subsequent "git fsck" will be less confused now. This is done before renaming the file, so git fsck is going to see (at most) a tmp_obj_?????? file, which it ignores in either case, right? > The real reason to make this change is that in a subsequent commit > we'll split this code in write_loose_object() into a utility function, > all its callers will want the preceding sanity checks, but not the > "oideq" check. By moving the close_loose_object() earlier it'll be > easier to reason about the introduction of the utility function. This sounds like a patch would move the close_loose_object() call to some other place, but that's not the case. The sequence below (starting from the close_loose_object() call) is still present after applying the whole series, so it seems this patch is not necessary. > > Signed-off-by: Ævar Arnfjörð Bjarmason > --- > object-file.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/object-file.c b/object-file.c > index 79eb8339b6..e4a83012ba 100644 > --- a/object-file.c > +++ b/object-file.c > @@ -2012,12 +2012,12 @@ static int write_loose_object(const struct object_id *oid, char *hdr, > die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid), > ret); > the_hash_algo->final_oid_fn(¶no_oid, &c); > + close_loose_object(fd, tmp_file.buf); > + > if (!oideq(oid, ¶no_oid)) > die(_("confused by unstable object source data for %s"), > oid_to_hex(oid)); > > - close_loose_object(fd, tmp_file.buf); > - > if (mtime) { > struct utimbuf utb; > utb.actime = mtime;