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author | Eric W. Biederman <ebiederm@xmission.com> | 2011-06-15 21:21:48 +0400 |
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committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-20 16:19:49 +0400 |
commit | 98f842e675f96ffac96e6c50315790912b2812be (patch) | |
tree | ed4dee9a6e54e3443e9f3f1614c8a2fcf9b31e0a /fs/ext4/inode.c | |
parent | bf056bfa80596a5d14b26b17276a56a0dcb080e5 (diff) | |
download | linux-98f842e675f96ffac96e6c50315790912b2812be.tar.xz |
proc: Usable inode numbers for the namespace file descriptors.
Assign a unique proc inode to each namespace, and use that
inode number to ensure we only allocate at most one proc
inode for every namespace in proc.
A single proc inode per namespace allows userspace to test
to see if two processes are in the same namespace.
This has been a long requested feature and only blocked because
a naive implementation would put the id in a global space and
would ultimately require having a namespace for the names of
namespaces, making migration and certain virtualization tricks
impossible.
We still don't have per superblock inode numbers for proc, which
appears necessary for application unaware checkpoint/restart and
migrations (if the application is using namespace file descriptors)
but that is now allowd by the design if it becomes important.
I have preallocated the ipc and uts initial proc inode numbers so
their structures can be statically initialized.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'fs/ext4/inode.c')
0 files changed, 0 insertions, 0 deletions