The commit 55ce74d4bfe1b9444436264c637f39a152d1e5ac (md/raid1: ensure
device failure recorded before write request returns) is causing crash in
the LVM2 testsuite test shell/lvchange-raid.sh. For me the crash is 100%
reproducible.
The reason for the crash is that the newly added code in raid1d moves the
list from conf->bio_end_io_list to tmp, then tests if tmp is non-empty and
then incorrectly pops the bio from conf->bio_end_io_list (which is empty
because the list was alrady moved).
Raid-10 has a similar bug.
Kernel Fault: Code=15 regs=000000006ccb8640 (Addr=0000000100000000)
CPU: 3 PID: 1930 Comm: mdX_raid1 Not tainted 4.2.0-rc5-bisect+ #35
task: 000000006cc1f258 ti: 000000006ccb8000 task.ti: 000000006ccb8000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001001111111000001111 Not tainted
r00-03 000000ff0804fe0f 000000001059d000 000000001059f818 000000007f16be38
r04-07 000000001059d000 000000007f16be08 0000000000200200 0000000000000001
r08-11 000000006ccb8260 000000007b7934d0 0000000000000001 0000000000000000
r12-15 000000004056f320 0000000000000000 0000000000013dd0 0000000000000000
r16-19 00000000f0d00ae0 0000000000000000 0000000000000000 0000000000000001
r20-23 000000000800000f 0000000042200390 0000000000000000 0000000000000000
r24-27 0000000000000001 000000000800000f 000000007f16be08 000000001059d000
r28-31 0000000100000000 000000006ccb8560 000000006ccb8640 0000000000000000
sr00-03 0000000000249800 0000000000000000 0000000000000000 0000000000249800
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 000000001059f61c 000000001059f620
IIR: 0f8010c6 ISR: 0000000000000000 IOR: 0000000100000000
CPU: 3 CR30: 000000006ccb8000 CR31: 0000000000000000
ORIG_R28: 000000001059d000
IAOQ[0]: call_bio_endio+0x34/0x1a8 [raid1]
IAOQ[1]: call_bio_endio+0x38/0x1a8 [raid1]
RP(r2): raid_end_bio_io+0x88/0x168 [raid1]
Backtrace:
[<000000001059f818>] raid_end_bio_io+0x88/0x168 [raid1]
[<00000000105a4f64>] raid1d+0x144/0x1640 [raid1]
[<000000004017fd5c>] kthread+0x144/0x160
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Fixes: 55ce74d4bfe1 ("md/raid1: ensure device failure recorded before write request returns.")
Fixes: 95af587e95aa ("md/raid10: ensure device failure recorded before write request returns.")
---
drivers/md/raid1.c | 4 ++--
drivers/md/raid10.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
Index: linux-2.6/drivers/md/raid1.c
===================================================================
--- linux-2.6.orig/drivers/md/raid1.c 2015-10-01 21:10:05.000000000 +0200
+++ linux-2.6/drivers/md/raid1.c 2015-10-01 21:10:58.000000000 +0200
@@ -2437,8 +2437,8 @@ static void raid1d(struct md_thread *thr
}
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
- r1_bio = list_first_entry(&conf->bio_end_io_list,
- struct r1bio, retry_list);
+ r1_bio = list_first_entry(&tmp, struct r1bio,
+ retry_list);
list_del(&r1_bio->retry_list);
raid_end_bio_io(r1_bio);
}
Index: linux-2.6/drivers/md/raid10.c
===================================================================
--- linux-2.6.orig/drivers/md/raid10.c 2015-10-01 21:11:02.000000000 +0200
+++ linux-2.6/drivers/md/raid10.c 2015-10-01 21:11:19.000000000 +0200
@@ -2804,8 +2804,8 @@ static void raid10d(struct md_thread *th
}
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
- r10_bio = list_first_entry(&conf->bio_end_io_list,
- struct r10bio, retry_list);
+ r10_bio = list_first_entry(&tmp, struct r10bio,
+ retry_list);
list_del(&r10_bio->retry_list);
raid_end_bio_io(r10_bio);
}
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