Linux sandbox: handle ENOSPC clone failure

Linux sandbox: handle ENOSPC clone failure

Linux 4.9 adds /proc/sys/user/max_user_namespaces to limit the number
of concurrent user namespaces.  Sometimes the limit is set to 0 in
which case clone() will return ENOSPC.  This CL avoids PCHECK()ing in
that case.

BUG=715138
R=mdempsky@chromium.org

Review-Url: https://codereview.chromium.org/2842033002
Cr-Commit-Position: refs/heads/master@{#467271}
Committed: https://chromium.googlesource.com/chromium/src/+/aebec0b4680564dfd5184cb288c07a2fd0ca50bd

[Tom (Use chromium acct), 2017-04-25 21:59:43]

mdempsky ptal

[mdempsky, 2017-04-26 06:56:37]

lgtm

[Tom (Use chromium acct), 2017-04-26 08:02:17]

The CQ bit was checked by thomasanderson@google.com

[commit-bot: I haz the power, 2017-04-26 08:02:28]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-26 08:50:19]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493193737915360, "parent_rev":
"3cba6ce1c4b98fb56f02556984813be8697b7729", "commit_rev":
"aebec0b4680564dfd5184cb288c07a2fd0ca50bd"}

[commit-bot: I haz the power, 2017-04-26 08:50:28]

Description was changed from

==========
Linux sandbox: handle ENOSPC clone failure

Linux 4.9 adds /proc/sys/user/max_user_namespaces to limit the number
of concurrent user namespaces.  Sometimes the limit is set to 0 in
which case clone() will return ENOSPC.  This CL avoids PCHECK()ing in
that case.

BUG=715138
R=mdempsky@chromium.org
==========

to

==========
Linux sandbox: handle ENOSPC clone failure

Linux 4.9 adds /proc/sys/user/max_user_namespaces to limit the number
of concurrent user namespaces.  Sometimes the limit is set to 0 in
which case clone() will return ENOSPC.  This CL avoids PCHECK()ing in
that case.

BUG=715138
R=mdempsky@chromium.org

Review-Url: https://codereview.chromium.org/2842033002
Cr-Commit-Position: refs/heads/master@{#467271}
Committed:
https://chromium.googlesource.com/chromium/src/+/aebec0b4680564dfd5184cb288c0...
==========

[commit-bot: I haz the power, 2017-04-26 08:50:29]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/aebec0b4680564dfd5184cb288c0...