This ends up a lot better IMO. This commit is *mostly* just
`s/glnx_close_fd/glnx_autofd`, but there's also a number of hunks like:
```
- if (self->sysroot_fd != -1)
- {
- (void) close (self->sysroot_fd);
- self->sysroot_fd = -1;
- }
+ glnx_close_fd (&self->sysroot_fd);
```
Update submodule: libglnx
Closes: #1259
Approved by: jlebon
Buried in this large patch is a logical fix:
```
- if (!map)
- return glnx_throw_errno_prefix (error, "mmap");
+ if (map == (void*)-1)
+ return glnx_null_throw_errno_prefix (error, "mmap");
```
Which would have helped me debug another patch I was working
on. But it turns out that actually correctly checking for
errors from `mmap()` triggers lots of other bugs - basically
because we sometimes handle zero-length variants (in detached
metadata). When we start actually returning errors due to
this, things break. (It wasn't a problem in practice before
because most things looked at the zero size, not the data).
Anyways there's a bigger picture issue here - a while ago
we made a fix to only use `mmap()` for reading metadata from disk
only if it was large enough (i.e. `>16k`). But that didn't
help various other paths in the pull code and others that were
directly doing the `mmap()`.
Fix this by having a proper low level fs helper that does "read all data from
fd+offset into GBytes", which handles the size check. Then the `GVariant` bits
are just a clean layer on top of this. (At the small cost of an additional
allocation)
Side note: I had to remind myself, but the reason we can't just use
`GMappedFile` here is it doesn't support passing an offset into `mmap()`.
Closes: #1251
Approved by: jlebon
We added a `.dir-locals.el` in commit: 9a77017d87
There's no need to have it per-file, with that people might think
to add other editors, which is the wrong direction.
Closes: #1206
Approved by: jlebon
We have `ot_ensure_unlinked_at()` for the "ignore ENOENT" case, and
`glnx_unlinkat()` otherwise. Port all in-tree callers to one or the other as
appropriate.
Just noticed an unprefixed error in the refs case and decided to do a tree-wide
check.
Closes: #1142
Approved by: jlebon
I added `glnx_open_anonymous_tmpfile()`, but then later noticed
that the usage of this was really to be combined with `mmap()`,
and we had two versions of that in the delta code. Add a helper.
(Bigger picture...how is this different from glibc's "mmap() of /dev/zero"
approach for large chunks? One advantage is the storage can be "swapped" to
`/var/tmp`, but still deleted automatically, rather than requiring swap space)
Closes: #973
Approved by: jlebon
There's lots of mechanically replacing `OtTmpFile` with `GLnxTmpfile`;
the biggest changes are in the commit path. Symlink commits are now
very clearly separated from regular files. Symlinks are `OtCleanupUnlinkat`,
and regular files are `GLnxTmpfile`.
The commit codepath separates those as `_ostree_repo_commit_path_final()` and
`_ostree_repo_commit_tmpf_final()`. A nice aspect of all of this is that they
both *consume* the temporary on success. This avoids an extra spurious
`unlink()` call.
One of the biggest bits of code motion is in `commit_loose_regfile_object()`,
which no longer needs to care about symlinks. For the most parth though it's
just removing conditionals.
Update submodule: libglnx
Closes: #958
Approved by: jlebon
I saw a few instances of `glnx_set_error_from_errno() + return FALSE`,
and fixed them and did a bit of style conversion.
Closes: #895
Approved by: jlebon
It's hard right now to do a full port to the new libglnx tmpfile
API since there are complex cases in the commit path which deal
with symlinks as well.
Let's make things more gradual by introducing the important part (struct with
autocleanup) here in libotutil, port what we can. This will make a future
complete port easier.
Closes: #871
Approved by: jlebon
Follow up to a previous patch that addressed a double-close; I
realized we already had a helper for doing "open dfd iter, do nothing
if we get ENOENT". Raise it to libotuil, and port all consumers.
Closes: #863
Approved by: jlebon
`perf record ostree checkout ...` for a bare-user repo was telling
me we were spending a good 13% of our time in the depchain of `ot_lgexattrat()`.
The problem here is that traversing the `/proc` path turns out to be
somewhat expensive - there are LSM (SELinux) checks, etc.
For regular files, opening and just getting the xattr, then closing is still
quite cheap. For symlinks, we'll always need to open anyways.
This appears to shave about ~0.1 seconds off of a checkout of
`fedora-atomic/25/x86_64/docker-host` on my workstation.
Oh, and this was the last user of `ot_lgexattrat()` so we can kill it, which is
nice - the xattr code should really live in libglnx.
Closes: #796
Approved by: jlebon
Lots and lots of preparation led to this moment - when nothing
apparent changes for users! Woo!
But seriously, having the extra dependency is a minor annoyance, and
in the big picture I think the libgsystem idea was wrong - we need to
land things in GLib, and use git submodules for API-unstable or
Linux-specific sharing. For a lot of OSTree, the libgsystem `GFile*`
orientation was also wrong, we really want fd-relative.
Closes: #444
Approved by: jlebon
This kills another GSystem consumer...I think down the line I'd like
to do something like "detect whether file is > 1k if so, mmap,
otherwise just readall()" so we can use this helper in more places.
Closes: #319
Approved by: jlebon
⚠️ There is a notable spiked pit trap here around
`posix_fallocate()` and `errno`. This has bit other projects,
see e.g.
7bb87460e6
Otherwise the port was straightforward.
An OSTree user noticed that `ostree fsck` would produce `missing
object` errors in the case of interrupted pulls.
It's possible to do e.g. `ostree pull --subpath=/usr/share/rpm ...`,
which gets you just that portion of the commit. The use case for this
was being able to see what changes would appear in an update before
actually downloading all of it.
(I think this would be better covered by static deltas, but those
aren't final yet, and `--subpath` predates it)
Further, `.commitpartial` is used as a successor to the `transaction`
symlink for more precise knowledge in the case where a pull was
interrupted that we needed to resume scanning.
So it makes sense for `ostree fsck` to be aware of it.
This is just an efficiency optimization. We're getting fairly close
to all of the hot code paths using `*at()`.
Note that we end up maintaining a half-duplicate code path set here,
because we still need to support commits from an arbitrary GFile *,
which in a possible common case is an OSTree commit.
I think it's worth it though.
Colin Walters
Giuseppe Scrivano
Matthew Barnes
Daniel Svensson
Alexander Larsson