To avoid unnecessary warnings and errors in the future I'd like to
propose building all cgo related sources with `-Wall -Werror`. This
commit fixes some warnings which came up in `shm_lock.c`, too.
Signed-off-by: Sascha Grunert <sgrunert@suse.com>
After a reboot, when we refresh Podman's state, we retrieved the
lock from the fresh SHM instance, but we did not mark it as
allocated to prevent it being handed out to other containers and
pods.
Provide a method for marking locks as in-use, and use it when we
refresh Podman state after a reboot.
Fixes#2900
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
The original intent behind the requirement was to ensure that, if
two SHM lock structs were open at the same time, we should not
make such a runtime available to the user, and should clean it up
instead.
It turns out that we don't even need to open a second SHM lock
struct - if we get an error mapping the first one due to a lock
count mismatch, we can just delete it, and it cleans itself up
when it errors. So there's no reason not to return a valid
runtime.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
When we're renumbering locks, we're destroying all existing
allocations anyways, so destroying the old lock struct is not a
particularly big deal. Existing long-lived libpod instances will
continue to use the old locks, but that will be solved in a
followon.
Also, solve an issue with returning error values in the C code.
There were a few places where we return ERRNO where it was not
set, so make them return actual error codes).
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
Renumber is a way of renumbering container locks after the number
of locks available has changed.
For now, renumber only works with containers.
Signed-off-by: Matthew Heon <matthew.heon@pm.me>
This patch makes the path unigue to each UID.
Also cleans up some return code to return the path it is trying to lock.
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Remove runtime's lockDir as it is no longer needed after the lock
rework.
Add a trivial in-memory lock manager for unit testing
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Golint wants to rename the struct. I think the name is fine. I
can disable golint. Golint will no longer complain about the
name.
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Move SHM specific code into a subpackage. Within the main locks
package, move the manager to be linux-only and add a non-Linux
unsupported build file.
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Check value of semaphores when incrementing to ensure we never go
beyond 1, preserving mutex invariants.
Also, add cleanup code to the lock tests, ensuring that we never
leave the locks in a bad state after a test. We aren't destroying
and recreating the SHM every time, so we have to be careful not
to leak state between test runs.
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
