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Groups > linux.kernel > #1624326
| From | Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3.18 094/145] dm: flush queued bios when process blocks to avoid deadlock |
| Date | 2017-04-16 13:10 +0200 |
| Message-ID | <twQe6-2WB-41@gated-at.bofh.it> (permalink) |
| References | <twQ4p-2E7-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mikulas Patocka <mpatocka@redhat.com>
commit d67a5f4b5947aba4bfe9a80a2b86079c215ca755 upstream.
Commit df2cb6daa4 ("block: Avoid deadlocks with bio allocation by
stacking drivers") created a workqueue for every bio set and code
in bio_alloc_bioset() that tries to resolve some low-memory deadlocks
by redirecting bios queued on current->bio_list to the workqueue if the
system is low on memory. However other deadlocks (see below **) may
happen, without any low memory condition, because generic_make_request
is queuing bios to current->bio_list (rather than submitting them).
** the related dm-snapshot deadlock is detailed here:
https://www.redhat.com/archives/dm-devel/2016-July/msg00065.html
Fix this deadlock by redirecting any bios on current->bio_list to the
bio_set's rescue workqueue on every schedule() call. Consequently,
when the process blocks on a mutex, the bios queued on
current->bio_list are dispatched to independent workqueus and they can
complete without waiting for the mutex to be available.
The structure blk_plug contains an entry cb_list and this list can contain
arbitrary callback functions that are called when the process blocks.
To implement this fix DM (ab)uses the onstack plug's cb_list interface
to get its flush_current_bio_list() called at schedule() time.
This fixes the snapshot deadlock - if the map method blocks,
flush_current_bio_list() will be called and it redirects bios waiting
on current->bio_list to appropriate workqueues.
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1267650
Depends-on: df2cb6daa4 ("block: Avoid deadlocks with bio allocation by stacking drivers")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/md/dm.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1300,11 +1300,62 @@ void dm_accept_partial_bio(struct bio *b
}
EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
+/*
+ * Flush current->bio_list when the target map method blocks.
+ * This fixes deadlocks in snapshot and possibly in other targets.
+ */
+struct dm_offload {
+ struct blk_plug plug;
+ struct blk_plug_cb cb;
+};
+
+static void flush_current_bio_list(struct blk_plug_cb *cb, bool from_schedule)
+{
+ struct dm_offload *o = container_of(cb, struct dm_offload, cb);
+ struct bio_list list;
+ struct bio *bio;
+
+ INIT_LIST_HEAD(&o->cb.list);
+
+ if (unlikely(!current->bio_list))
+ return;
+
+ list = *current->bio_list;
+ bio_list_init(current->bio_list);
+
+ while ((bio = bio_list_pop(&list))) {
+ struct bio_set *bs = bio->bi_pool;
+ if (unlikely(!bs) || bs == fs_bio_set) {
+ bio_list_add(current->bio_list, bio);
+ continue;
+ }
+
+ spin_lock(&bs->rescue_lock);
+ bio_list_add(&bs->rescue_list, bio);
+ queue_work(bs->rescue_workqueue, &bs->rescue_work);
+ spin_unlock(&bs->rescue_lock);
+ }
+}
+
+static void dm_offload_start(struct dm_offload *o)
+{
+ blk_start_plug(&o->plug);
+ o->cb.callback = flush_current_bio_list;
+ list_add(&o->cb.list, ¤t->plug->cb_list);
+}
+
+static void dm_offload_end(struct dm_offload *o)
+{
+ list_del(&o->cb.list);
+ blk_finish_plug(&o->plug);
+}
+
static void __map_bio(struct dm_target_io *tio)
{
int r;
sector_t sector;
struct mapped_device *md;
+ struct dm_offload o;
struct bio *clone = &tio->clone;
struct dm_target *ti = tio->ti;
@@ -1317,7 +1368,11 @@ static void __map_bio(struct dm_target_i
*/
atomic_inc(&tio->io->io_count);
sector = clone->bi_iter.bi_sector;
+
+ dm_offload_start(&o);
r = ti->type->map(ti, clone);
+ dm_offload_end(&o);
+
if (r == DM_MAPIO_REMAPPED) {
/* the bio has been remapped so dispatch it */
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[PATCH 3.18 000/145] 3.18.49-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 099/145] drm/ast: Fix AST2400 POST failure without BMC FW or VBIOS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 032/145] selinux: fix off-by-one in setprocattr Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 140/145] tcp: fix various issues for sockets morphing to listen state Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 041/145] [PATCH 087/760] net: pktgen: remove rcu locking in pktgen_change_name() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 084/145] usb: dwc3: gadget: make Set Endpoint Configuration macros safe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 143/145] uapi: fix linux/packet_diag.h userspace compilation error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:00 +0200
[PATCH 3.18 125/145] KVM: s390: Fix guest migration for huge guests resulting in panic Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 104/145] vxlan: correctly validate VXLAN ID against VXLAN_N_VID Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 095/145] padata: avoid race in reordering Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 083/145] usb: gadget: dummy_hcd: clear usb_gadget region before registration Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 129/145] USB: uss720: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 132/145] USB: wusbcore: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 109/145] dccp: Unlock sock before calling sk_free() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 141/145] net: fix socket refcounting in skb_complete_wifi_ack() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 101/145] cpmac: remove hopeless #warning Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 110/145] net/packet: fix overflow in check for priv area size Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 117/145] crypto: cryptd - Assign statesize properly Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 098/145] drm/ast: Call open_key before enable_mmio in POST code Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 078/145] libceph: use BUG() instead of BUG_ON(1) Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 123/145] s390: make setup_randomness work Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 075/145] nlm: Ensure callback code also checks that the files match Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 130/145] USB: lvtest: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 137/145] MIPS: DEC: Avoid la pseudo-instruction in delay slots Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 139/145] libceph: dont set weight to IN when OSD is destroyed Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 111/145] usb: hub: Wait for connection to be reestablished after port reset Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 094/145] dm: flush queued bios when process blocks to avoid deadlock Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 082/145] mtd: pmcmsp: use kstrndup instead of kmalloc+strncpy Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 135/145] MIPS: ip27: Disable qlge driver in defconfig Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 091/145] USB: serial: io_ti: fix NULL-deref in interrupt callback Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 118/145] crypto: mcryptd - Fix load failure Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 122/145] s390: TASK_SIZE for kernel threads Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 115/145] futex: Fix potential use-after-free in FUTEX_REQUEUE_PI Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 106/145] ipv4: mask tos for input route Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 134/145] USB: fix linked-list corruption in rh_call_control() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 102/145] tracing: Add #undef to fix compile error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 136/145] MIPS: ip22: Fix ip28 build for modern gcc Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:10 +0200
[PATCH 3.18 052/145] drivers: staging: nvec: remove bogus reset command for PS/2 interface Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 042/145] [PATCH 091/760] ipv4: disable BH in set_ping_group_range() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 090/145] USB: iowarrior: fix NULL-deref in write Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 035/145] [PATCH 074/760] tcp: fix a compile error in DBGUNDO() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 060/145] lib/vsprintf.c: improve sanity check in vsnprintf() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 030/145] pwm: Unexport children before chip removal Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 068/145] staging: android: ashmem: lseek failed due to no FMODE_LSEEK. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 071/145] Bluetooth: Add another AR3012 04ca:3018 device Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 057/145] net/llc: avoid BUG_ON() in skb_orphan() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 087/145] USB: serial: safe_serial: fix information leak in completion handler Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 070/145] KVM: s390: Disable dirty log retrieval for UCONTROL guests Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 089/145] USB: iowarrior: fix NULL-deref at probe Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 046/145] [PATCH 083/760] netlink: do not enter direct reclaim from netlink_dump() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 065/145] xfrm: policy: init locks early Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 074/145] USB: serial: digi_acceleport: fix OOB-event processing Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 076/145] xtensa: move parse_tag_fdt out of #ifdef CONFIG_BLK_DEV_INITRD Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 007/145] ipv4: keep skb->dst around in presence of IP options Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 050/145] coredump: fix unfreezable coredumping task Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 043/145] [PATCH 093/760] net: sctp, forbid negative length Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 072/145] IB/ipoib: Fix deadlock between rmmod and set_mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 069/145] serial: 8250_pci: Add MKS Tenta SCOM-0800 and SCOM-0801 cards Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 047/145] ASoC: cs4270: fix DAPM stream name mismatch Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 054/145] USB: cdc-acm: fix TIOCMIWAIT Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 036/145] [PATCH 075/760] ip6_gre: fix flowi6_proto value in ip6gre_xmit_other() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 005/145] tcp: fix 0 divide in __tcp_select_window() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 085/145] usb: gadget: function: f_fs: pass companion descriptor along Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 063/145] cancel the setfilesize transation when io error happen Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 051/145] staging: iio: ad5933: avoid uninitialized variable in error case Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 064/145] raid10: increment write counter after bio is split Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 059/145] net: socket: fix recvmmsg not returning error from sock_error Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 037/145] [PATCH 076/760] ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 049/145] swapfile: fix memory corruption via malformed swapfile Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 062/145] tty: n_hdlc: get rid of racy n_hdlc.tbuf Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:20 +0200
[PATCH 3.18 028/145] smc91x: avoid self-comparison warning Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 015/145] [PATCH 084/760] ipv6: tcp: restore IP6CB for pktoptions skbs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 012/145] ping: fix a null pointer dereference Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 020/145] tcp: fix overflow in __tcp_retransmit_skb() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 019/145] usb: chipidea: move the lock initialization to core file Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 002/145] can: Fix kernel panic at security_sock_rcv_skb Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 031/145] HID: usbhid: add ATEN CS962 to list of quirky devices Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 027/145] drm/exynos: fix error handling in exynos_drm_subdrv_open Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 033/145] fbdev: color map copying bounds checking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
[PATCH 3.18 023/145] ALSA: usb-audio: Add quirk for Syntek STK1160 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-16 13:30 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Guenter Roeck <linux@roeck-us.net> - 2017-04-17 01:40 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-17 09:00 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Amit Pundir <amit.pundir@linaro.org> - 2017-04-17 10:10 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-17 10:30 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-04-17 20:20 +0200
Re: [PATCH 3.18 000/145] 3.18.49-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-04-18 07:00 +0200
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