| From foo@baz Mon Apr 9 17:09:24 CEST 2018 |
| From: Julia Cartwright <julia@ni.com> |
| Date: Fri, 28 Apr 2017 12:41:02 -0500 |
| Subject: md/raid5: make use of spin_lock_irq over local_irq_disable + spin_lock |
| |
| From: Julia Cartwright <julia@ni.com> |
| |
| |
| [ Upstream commit 3d05f3aed5d721c2c77d20288c29ab26c6193ed5 ] |
| |
| On mainline, there is no functional difference, just less code, and |
| symmetric lock/unlock paths. |
| |
| On PREEMPT_RT builds, this fixes the following warning, seen by |
| Alexander GQ Gerasiov, due to the sleeping nature of spinlocks. |
| |
| BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993 |
| in_atomic(): 0, irqs_disabled(): 1, pid: 58, name: kworker/u12:1 |
| CPU: 5 PID: 58 Comm: kworker/u12:1 Tainted: G W 4.9.20-rt16-stand6-686 #1 |
| Hardware name: Supermicro SYS-5027R-WRF/X9SRW-F, BIOS 3.2a 10/28/2015 |
| Workqueue: writeback wb_workfn (flush-253:0) |
| Call Trace: |
| dump_stack+0x47/0x68 |
| ? migrate_enable+0x4a/0xf0 |
| ___might_sleep+0x101/0x180 |
| rt_spin_lock+0x17/0x40 |
| add_stripe_bio+0x4e3/0x6c0 [raid456] |
| ? preempt_count_add+0x42/0xb0 |
| raid5_make_request+0x737/0xdd0 [raid456] |
| |
| Reported-by: Alexander GQ Gerasiov <gq@redlab-i.ru> |
| Tested-by: Alexander GQ Gerasiov <gq@redlab-i.ru> |
| Signed-off-by: Julia Cartwright <julia@ni.com> |
| Signed-off-by: Shaohua Li <shli@fb.com> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/md/raid5.c | 17 +++++++---------- |
| 1 file changed, 7 insertions(+), 10 deletions(-) |
| |
| --- a/drivers/md/raid5.c |
| +++ b/drivers/md/raid5.c |
| @@ -110,8 +110,7 @@ static inline void unlock_device_hash_lo |
| static inline void lock_all_device_hash_locks_irq(struct r5conf *conf) |
| { |
| int i; |
| - local_irq_disable(); |
| - spin_lock(conf->hash_locks); |
| + spin_lock_irq(conf->hash_locks); |
| for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++) |
| spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks); |
| spin_lock(&conf->device_lock); |
| @@ -121,9 +120,9 @@ static inline void unlock_all_device_has |
| { |
| int i; |
| spin_unlock(&conf->device_lock); |
| - for (i = NR_STRIPE_HASH_LOCKS; i; i--) |
| - spin_unlock(conf->hash_locks + i - 1); |
| - local_irq_enable(); |
| + for (i = NR_STRIPE_HASH_LOCKS - 1; i; i--) |
| + spin_unlock(conf->hash_locks + i); |
| + spin_unlock_irq(conf->hash_locks); |
| } |
| |
| /* bio's attached to a stripe+device for I/O are linked together in bi_sector |
| @@ -732,12 +731,11 @@ static bool is_full_stripe_write(struct |
| |
| static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2) |
| { |
| - local_irq_disable(); |
| if (sh1 > sh2) { |
| - spin_lock(&sh2->stripe_lock); |
| + spin_lock_irq(&sh2->stripe_lock); |
| spin_lock_nested(&sh1->stripe_lock, 1); |
| } else { |
| - spin_lock(&sh1->stripe_lock); |
| + spin_lock_irq(&sh1->stripe_lock); |
| spin_lock_nested(&sh2->stripe_lock, 1); |
| } |
| } |
| @@ -745,8 +743,7 @@ static void lock_two_stripes(struct stri |
| static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2) |
| { |
| spin_unlock(&sh1->stripe_lock); |
| - spin_unlock(&sh2->stripe_lock); |
| - local_irq_enable(); |
| + spin_unlock_irq(&sh2->stripe_lock); |
| } |
| |
| /* Only freshly new full stripe normal write stripe can be added to a batch list */ |