Mikulas Patocka 1f145073b1 dm: fix deadlock when swapping to encrypted device ... commit a666e5c05e upstream. The system would deadlock when swapping to a dm-crypt device. The reason is that for each incoming write bio, dm-crypt allocates memory that holds encrypted data. These excessive allocations exhaust all the memory and the result is either deadlock or OOM trigger. This patch limits the number of in-flight swap bios, so that the memory consumed by dm-crypt is limited. The limit is enforced if the target set the "limit_swap_bios" variable and if the bio has REQ_SWAP set. Non-swap bios are not affected becuase taking the semaphore would cause performance degradation. This is similar to request-based drivers - they will also block when the number of requests is over the limit. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-03-04 11:38:44 +01:00
..
acpi	ACPICA: Fix exception code class checks	2021-03-04 11:37:24 +01:00
asm-generic	vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y	2021-03-04 11:37:19 +01:00
clocksource
crypto
drm	drm/dp/mst: Export drm_dp_get_vc_payload_bw()	2021-02-10 09:29:18 +01:00
dt-bindings	ASoC: dt-bindings: lpass: Fix and common up lpass dai ids	2021-02-03 23:28:46 +01:00
keys
kunit	kunit: fix display of failed expectations for strings	2020-11-10 13:45:15 -07:00
kvm
linux	dm: fix deadlock when swapping to encrypted device	2021-03-04 11:38:44 +01:00
math-emu
media	media: v4l2-fwnode: v4l2_fwnode_endpoint_parse caller must init vep argument	2020-12-30 11:53:11 +01:00
memory
misc
net	tcp: fix SO_RCVLOWAT related hangs under mem pressure	2021-03-04 11:37:33 +01:00
pcmcia
ras
rdma	RDMA: Lift ibdev_to_node from rds to common code	2021-02-26 10:12:59 +01:00
scsi	scsi: libiscsi: Fix NOP race condition	2020-11-16 22:32:50 -05:00
soc	net: dsa: felix: implement port flushing on .phylink_mac_link_down	2021-02-17 11:02:27 +01:00
sound	ASoC: Fixes for v5.11	2020-11-19 19:56:29 +01:00
target
trace	trace: fix potenial dangerous pointer	2020-11-25 13:03:44 +01:00
uapi	drm/fourcc: fix Amlogic format modifier masks	2021-03-04 11:37:38 +01:00
vdso
video
xen	Xen/gntdev: correct error checking in gntdev_map_grant_pages()	2021-02-23 15:53:24 +01:00