dm crypt: use GFP_ATOMIC when allocating crypto requests from softirq
Commit 39d42fa9 ("dm crypt: add flags to optionally bypass kcryptd workqueues") made it possible for some code paths in dm-crypt to be executed in softirq context, when the underlying driver processes IO requests in interrupt/softirq context. In this case sometimes when allocating a new crypto request we may get a stacktrace like below: [ 210.103008][ C0] BUG: sleeping function called from invalid context at mm/mempool.c:381 [ 210.104746][ C0] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2602, name: fio [ 210.106599][ C0] CPU: 0 PID: 2602 Comm: fio Tainted: G W 5.10.0+ #50 [ 210.108331][ C0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 [ 210.110212][ C0] Call Trace: [ 210.110921][ C0] <IRQ> [ 210.111527][ C0] dump_stack+0x7d/0xa3 [ 210.112411][ C0] ___might_sleep.cold+0x122/0x151 [ 210.113527][ C0] mempool_alloc+0x16b/0x2f0 [ 210.114524][ C0] ? __queue_work+0x515/0xde0 [ 210.115553][ C0] ? mempool_resize+0x700/0x700 [ 210.116586][ C0] ? crypt_endio+0x91/0x180 [ 210.117479][ C0] ? blk_update_request+0x757/0x1150 [ 210.118513][ C0] ? blk_mq_end_request+0x4b/0x480 [ 210.119572][ C0] ? blk_done_softirq+0x21d/0x340 [ 210.120628][ C0] ? __do_softirq+0x190/0x611 [ 210.121626][ C0] crypt_convert+0x29f9/0x4c00 [ 210.122668][ C0] ? _raw_spin_lock_irqsave+0x87/0xe0 [ 210.123824][ C0] ? kasan_set_track+0x1c/0x30 [ 210.124858][ C0] ? crypt_iv_tcw_ctr+0x4a0/0x4a0 [ 210.125930][ C0] ? kmem_cache_free+0x104/0x470 [ 210.126973][ C0] ? crypt_endio+0x91/0x180 [ 210.127947][ C0] kcryptd_crypt_read_convert+0x30e/0x420 [ 210.129165][ C0] blk_update_request+0x757/0x1150 [ 210.130231][ C0] blk_mq_end_request+0x4b/0x480 [ 210.131294][ C0] blk_done_softirq+0x21d/0x340 [ 210.132332][ C0] ? _raw_spin_lock+0x81/0xd0 [ 210.133289][ C0] ? blk_mq_stop_hw_queue+0x30/0x30 [ 210.134399][ C0] ? _raw_read_lock_irq+0x40/0x40 [ 210.135458][ C0] __do_softirq+0x190/0x611 [ 210.136409][ C0] ? handle_edge_irq+0x221/0xb60 [ 210.137447][ C0] asm_call_irq_on_stack+0x12/0x20 [ 210.138507][ C0] </IRQ> [ 210.139118][ C0] do_softirq_own_stack+0x37/0x40 [ 210.140191][ C0] irq_exit_rcu+0x110/0x1b0 [ 210.141151][ C0] common_interrupt+0x74/0x120 [ 210.142171][ C0] asm_common_interrupt+0x1e/0x40 Fix this by allocating crypto requests with GFP_ATOMIC mask in interrupt context. Fixes: 39d42fa9 ("dm crypt: add flags to optionally bypass kcryptd workqueues") Cc: stable@vger.kernel.org # v5.9+ Reported-by:Maciej S. Szmigiero <mail@maciej.szmigiero.name> Signed-off-by:
Ignat Korchagin <ignat@cloudflare.com> Acked-by:
Mikulas Patocka <mpatocka@redhat.com> Signed-off-by:
Mike Snitzer <snitzer@redhat.com>
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8abec36d
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