RDMA/rxe: Do not call dev_mc_add/del() under a spinlock
These routines were not intended to be called under a spinlock and will
throw debugging warnings:
raw_local_irq_restore() called with IRQs enabled
WARNING: CPU: 13 PID: 3107 at kernel/locking/irqflag-debug.c:10 warn_bogus_irq_restore+0x2f/0x50
CPU: 13 PID: 3107 Comm: python3 Tainted: G E 5.18.0-rc1+ #7
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:warn_bogus_irq_restore+0x2f/0x50
Call Trace:
<TASK>
_raw_spin_unlock_irqrestore+0x75/0x80
rxe_attach_mcast+0x304/0x480 [rdma_rxe]
ib_attach_mcast+0x88/0xa0 [ib_core]
ib_uverbs_attach_mcast+0x186/0x1e0 [ib_uverbs]
ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xcd/0x140 [ib_uverbs]
ib_uverbs_cmd_verbs+0xdb0/0xea0 [ib_uverbs]
ib_uverbs_ioctl+0xd2/0x160 [ib_uverbs]
do_syscall_64+0x5c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Move them out of the spinlock, it is OK if there is some races setting up
the MC reception at the ethernet layer with rbtree lookups.
Fixes:
6090a0c4c7c6 ("RDMA/rxe: Cleanup rxe_mcast.c")
Link: https://lore.kernel.org/r/20220504202817.98247-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>