All accesses to the event counters are serialized by rdmacg_mutex,
making the READ_ONCE() annotations unnecessary. Remove them.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

Add per-cgroup local event counters to track RDMA resource limit
exhaustion from the perspective of individual cgroups. The
rdma.events.local file reports two per-resource counters:

- max: number of times this cgroup's limit was the one that blocked
  an allocation in the subtree
- alloc_fail: number of allocation attempts originating from this
  cgroup that failed due to an ancestor's limit

This mirrors the design of pids.events.local, where events are
attributed to the cgroup that imposed the limit, not necessarily the
cgroup where the allocation was attempted.

Also extend rdma.events with a hierarchical alloc_fail counter that
tracks allocation failures propagating upward from the requesting
cgroup, complementing the existing max counter, so that rdma.events
and rdma.events.local share the same output format.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

Add per-device hierarchical event counters to track when RDMA resource
limits are exceeded. The rdma.events file reports max event counts
propagated upward from the cgroup whose limit was hit to all ancestors.

This mirrors the design of pids.events, where events are attributed to
the cgroup that imposed the limit, not necessarily the cgroup where the
allocation was attempted. Userspace can monitor this file via
poll/epoll for real-time notification of resource exhaustion.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

rdma.peak tracks the high watermark of resource usage per device,
giving a better baseline on which to set rdma.max. Polling
rdma.current isn't feasible since it would miss short-lived spikes.

This interface is analogous to memory.peak.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

Replace the hand-rolled strsep/strcmp/match_string parsing in
rdmacg_resource_set_max() with a match_table_t and match_token()
pattern, following the convention used by user_proactive_reclaim()
and ioc_cost_model_write().

The old strncmp(value, RDMACG_MAX_STR, strlen(value)) also had two
bugs that are fixed by this refactor:

  - It matched "ma" as "max" because strncmp only compared the
    shorter strlen(value) bytes.

  - It silently accepted "hca_handle=" (empty value) as "max"
    because strncmp with n=0 always returns 0.

The match_token() approach also robustly handles extra whitespace in
the input by splitting on " \t\n" and skipping empty tokens.

Suggested-by: "Michal Koutný" <mkoutny@suse.com>
Signed-off-by: Tao Cui <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

The expression `rpool->resources[index].usage + 1` is computed in int
arithmetic before being assigned to s64 variable `new`. When usage equals
INT_MAX (the default "max" value), the addition overflows to INT_MIN.
This negative value then passes the `new > max` check incorrectly,
allowing a charge that should be rejected and corrupting usage to
negative.

Fix by casting usage to s64 before the addition so the arithmetic is
done in 64-bit.

Fixes: 39d3e7584a68 ("rdmacg: Added rdma cgroup controller")
Signed-off-by: cuitao <cuitao@kylinos.cn>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

The format string says "device %p ... rdma cgroup %p" but the arguments
were passed as (cg, device), printing them in the wrong order.

Signed-off-by: cuitao <cuitao@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

Fix all kernel-doc warnings in rdmacg:

kernel/cgroup/rdma.c:209: warning: Function parameter or member 'cg'
not described in 'rdmacg_uncharge_hierarchy'
kernel/cgroup/rdma.c:230: warning: Function parameter or member 'cg'
not described in 'rdmacg_uncharge'

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>