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checkout: Add force_copy+SELinux options for checkout, use in deploy #797

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@cgwalters cgwalters commented Apr 14, 2017

This is a variant of the efforts in #741
Working on rpm-ostree livefs, I realized though I needed to just
check out new files directly into the live /etc (and possibly
delete obsolete files).

The way the current /etc merge works is fundamentally different from
that. So my plan currently is to probably do something like:

  • Compute diff
  • Check out each new file individually (as a copy)
  • Optionally delete obsolete files

Also, a few other things become more important - in the current deploy code, we
copy all of the files, then relabel them. But we shouldn't expose to live
systems the race conditions of doing that, plus we should only relabel files we
checked out.

By converting the deploy's /etc code to use this, we fix the same TODO item
there around atomically having the label set up as we create files. And further,
if we kill the /var relabeling which I think is unnecessary since Anaconda
does it, we could delete large chunks of code there.

@cgwalters cgwalters added the WIP label Apr 14, 2017
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WIP, needs more testing. Also I note that we should really make more use of setfscreatecon() for dealing with the SELinux xattr... and basically have glnx_set_xattrs_except_selinux().

@cgwalters cgwalters force-pushed the checkout-labeling branch 2 times, most recently from 79ea5ba to 3d14c7a Compare April 19, 2017 18:26
@cgwalters cgwalters removed the WIP label Apr 19, 2017
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OK, removing WIP. I've tested this manually on a F25AH host. Note this rolls in #801

@@ -767,14 +767,17 @@ typedef struct {
gboolean enable_fsync; /* Deprecated */
gboolean process_whiteouts;
gboolean no_copy_fallback;
gboolean unused_bools[7];
gboolean force_copy;
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I may break this out as a separate PR too with exposure via the cmdline as well.

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☔ The latest upstream changes (presumably 50ca653) made this pull request unmergeable. Please resolve the merge conflicts.

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🏄‍♂️ Rebased

This depends on #804 and #801

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This looks good. Though it'd be really nice if we had #771 as an added check here.

&label, cancellable, error))
return FALSE;
if (fsetxattr (temp_fd, "security.selinux", label, strlen (label), 0) < 0)
return glnx_throw_errno_prefix (error, "Setting security.selinux");
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Nit: would be helpful to include the name of the file in the error msg.

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We already do that via the
return g_prefix_error (error, "Checkout of %s to %s: ", checksum, destination_name), FALSE;
in the caller.

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Ahh, got it.

state.selabel_path_buf = buf;

/* Otherwise it'd just be corrupting things, and there's no use case */
g_assert (options->force_copy);
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Hmm, let's enforce this at the API entry point too.

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This was already very close to the entrypoint, but OK. Fixup ⬇️

@@ -579,22 +652,15 @@ checkout_tree_at (OstreeRepo *self,
(guint64)repo_dfd_stat.st_dev, (guint64)destination_stat.st_dev);

/* Set the xattrs now, so any derived labeling works */
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Can we update this comment as well since we might have done labeling already above?

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☔ The latest upstream changes (presumably 511b31c) made this pull request unmergeable. Please resolve the merge conflicts.

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jlebon commented Apr 25, 2017

Let's land #807 first before merging this one.

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jlebon commented Apr 25, 2017

🚄 @rh-atomic-bot r+ 8aefb93

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⌛ Testing commit 8aefb93 with merge dadb5f8...

rh-atomic-bot pushed a commit that referenced this pull request Apr 25, 2017
This is a variant of the efforts in #741
Working on `rpm-ostree livefs`, I realized though I needed to just
check out *new* files directly into the live `/etc` (and possibly
delete obsolete files).

The way the current `/etc` merge works is fundamentally different from
that.  So my plan currently is to probably do something like:

 - Compute diff
 - Check out each *new* file individually (as a copy)
 - Optionally delete obsolete files

Also, a few other things become more important - in the current deploy code, we
copy all of the files, then relabel them. But we shouldn't expose to *live*
systems the race conditions of doing that, plus we should only relabel files we
checked out.

By converting the deploy's /etc code to use this, we fix the same TODO item
there around atomically having the label set up as we create files. And further,
if we kill the `/var` relabeling which I think is unnecessary since Anaconda
does it, we could delete large chunks of code there.

In the implementation, there are two types of things: regular files, and
symlinks. For regular files, in the `O_TMPFILE` case, we have the ability to
do *everything* atomically (including SELinux labeling) before linking it into
place. So let's just use that. For symlinks, we use `setfscreatecon()`.

Closes: #797
Approved by: jlebon
This is a variant of the efforts in ostreedev#741
Working on `rpm-ostree livefs`, I realized though I needed to just
check out *new* files directly into the live `/etc` (and possibly
delete obsolete files).

The way the current `/etc` merge works is fundamentally different from
that.  So my plan currently is to probably do something like:

 - Compute diff
 - Check out each *new* file individually (as a copy)
 - Optionally delete obsolete files

Also, a few other things become more important - in the current deploy code, we
copy all of the files, then relabel them. But we shouldn't expose to *live*
systems the race conditions of doing that, plus we should only relabel files we
checked out.

By converting the deploy's /etc code to use this, we fix the same TODO item
there around atomically having the label set up as we create files. And further,
if we kill the `/var` relabeling which I think is unnecessary since Anaconda
does it, we could delete large chunks of code there.

In the implementation, there are two types of things: regular files, and
symlinks. For regular files, in the `O_TMPFILE` case, we have the ability to
do *everything* atomically (including SELinux labeling) before linking it into
place. So let's just use that. For symlinks, we use `setfscreatecon()`.
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jlebon commented Apr 25, 2017

Weird, the status did get reported.
@rh-atomic-bot retry

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jlebon commented Apr 25, 2017

@rh-atomic-bot retry

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jlebon commented Apr 25, 2017

Ohh I see.
@rh-atomic-bot r+ 2048b88

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⌛ Testing commit 2048b88 with merge e8efd1c...

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☀️ Test successful - status-atomicjenkins
Approved by: jlebon
Pushing e8efd1c to master...

cgwalters added a commit to cgwalters/ostree that referenced this pull request Apr 26, 2017
This fixes a regression from:
ostreedev#797
which is really due to an underlying bug in libselinux which
we're working around:
http://marc.info/?l=selinux&m=149323809332417&w=2

We drop the per-policy instance variable, since the SELinux state
is *really* per-kernel.
cgwalters added a commit to cgwalters/ostree that referenced this pull request Apr 26, 2017
This fixes a regression from:
ostreedev#797
which is really due to an underlying bug in libselinux which
we're working around:
http://marc.info/?l=selinux&m=149323809332417&w=2

We drop the per-policy instance variable, since the SELinux state
is *really* per-kernel.

Closes: ostreedev#814
stephensmalley pushed a commit to SELinuxProject/selinux that referenced this pull request Apr 27, 2017
This breaks every further call to e.g. `is_selinux_enabled()` after a policy
root has been set.  This tripped up some code landed in libostree:
ostreedev/ostree#797
Since in some cases we initialize a policy twice in process, and we'd
call `is_selinux_enabled()` each time.

More info in: http://marc.info/?l=selinux&m=149323809332417&w=2

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
rh-atomic-bot pushed a commit that referenced this pull request Apr 27, 2017
This fixes a regression from:
#797
which is really due to an underlying bug in libselinux which
we're working around:
http://marc.info/?l=selinux&m=149323809332417&w=2

We drop the per-policy instance variable, since the SELinux state
is *really* per-kernel.

Closes: #814

Closes: #815
Approved by: jlebon
cgwalters added a commit to cgwalters/ostree that referenced this pull request Apr 27, 2017
Rather than `g_output_stream_splice()`, where the input is a regular
file.

See GNOME/libglnx#44 for some more information.

I didn't try to measure the performance difference, but seeing the
read()/write() to/from userspace mixed in with the pointless `poll()` annoyed me
when reading strace.

As a bonus, we will again start using reflinks (if available) for `/etc`,
which is a regression from the ostreedev#797
changes (which before used `glnx_file_copy_at()`).

Also, for the first time we'll use reflinks when doing commits from file-backed
content. This happens in `rpm-ostree compose tree` today for example.
bachradsusi pushed a commit to fedora-selinux/selinux that referenced this pull request Apr 28, 2017
This breaks every further call to e.g. `is_selinux_enabled()` after a policy
root has been set.  This tripped up some code landed in libostree:
ostreedev/ostree#797
Since in some cases we initialize a policy twice in process, and we'd
call `is_selinux_enabled()` each time.

More info in: http://marc.info/?l=selinux&m=149323809332417&w=2

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
(cherry picked from SELinuxProject commit f3a264c)
cgwalters added a commit to cgwalters/ostree that referenced this pull request May 1, 2017
Rather than `g_output_stream_splice()`, where the input is a regular
file.

See GNOME/libglnx#44 for some more information.

I didn't try to measure the performance difference, but seeing the
read()/write() to/from userspace mixed in with the pointless `poll()` annoyed me
when reading strace.

As a bonus, we will again start using reflinks (if available) for `/etc`,
which is a regression from the ostreedev#797
changes (which before used `glnx_file_copy_at()`).

Also, for the first time we'll use reflinks when doing commits from file-backed
content. This happens in `rpm-ostree compose tree` today for example.

Update submodule: libglnx
cgwalters added a commit to cgwalters/ostree that referenced this pull request May 1, 2017
Rather than `g_output_stream_splice()`, where the input is a regular
file.

See GNOME/libglnx#44 for some more information.

I didn't try to measure the performance difference, but seeing the
read()/write() to/from userspace mixed in with the pointless `poll()` annoyed me
when reading strace.

As a bonus, we will again start using reflinks (if available) for `/etc`,
which is a regression from the ostreedev#797
changes (which before used `glnx_file_copy_at()`).

Also, for the first time we'll use reflinks when doing commits from file-backed
content. This happens in `rpm-ostree compose tree` today for example.

Update submodule: libglnx
cgwalters added a commit to cgwalters/ostree that referenced this pull request May 1, 2017
Rather than `g_output_stream_splice()`, where the input is a regular
file.

See GNOME/libglnx#44 for some more information.

I didn't try to measure the performance difference, but seeing the
read()/write() to/from userspace mixed in with the pointless `poll()` annoyed me
when reading strace.

As a bonus, we will again start using reflinks (if available) for `/etc`,
which is a regression from the ostreedev#797
changes (which before used `glnx_file_copy_at()`).

Also, for the first time we'll use reflinks when doing commits from file-backed
content. This happens in `rpm-ostree compose tree` today for example.

Update submodule: libglnx
rh-atomic-bot pushed a commit that referenced this pull request May 10, 2017
Rather than `g_output_stream_splice()`, where the input is a regular
file.

See GNOME/libglnx#44 for some more information.

I didn't try to measure the performance difference, but seeing the
read()/write() to/from userspace mixed in with the pointless `poll()` annoyed me
when reading strace.

As a bonus, we will again start using reflinks (if available) for `/etc`,
which is a regression from the #797
changes (which before used `glnx_file_copy_at()`).

Also, for the first time we'll use reflinks when doing commits from file-backed
content. This happens in `rpm-ostree compose tree` today for example.

Update submodule: libglnx

Closes: #817
Approved by: jlebon
bachradsusi pushed a commit to fedora-selinux/selinux that referenced this pull request Jul 28, 2017
This breaks every further call to e.g. `is_selinux_enabled()` after a policy
root has been set.  This tripped up some code landed in libostree:
ostreedev/ostree#797
Since in some cases we initialize a policy twice in process, and we'd
call `is_selinux_enabled()` each time.

More info in: http://marc.info/?l=selinux&m=149323809332417&w=2

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
(cherry picked from SELinuxProject commit f3a264c)
chenyt9 pushed a commit to MotorolaMobilityLLC/external-selinux that referenced this pull request Jul 6, 2018
This breaks every further call to e.g. `is_selinux_enabled()` after a policy
root has been set.  This tripped up some code landed in libostree:
ostreedev/ostree#797
Since in some cases we initialize a policy twice in process, and we'd
call `is_selinux_enabled()` each time.

More info in: http://marc.info/?l=selinux&m=149323809332417&w=2

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
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