Hi,
在 2025/08/17 19:31, Yunseong Kim 写道:
The function ppl_io_unit_finished() uses a local_irq_save()/spin_lock()
sequence. On a PREEMPT_RT enabled kernel, spin_lock() can sleep. Calling it
with interrupts disabled creates an atomic context where sleeping is
forbidden.
What? I believe spin_lock can never sleep.
Ensuring that the interrupt state is managed atomically with the lock
itself. The change is applied to both the 'log->io_list_lock' and
'ppl_conf->no_mem_stripes_lock' critical sections within the function.
Signed-off-by: Yunseong Kim <ysk@xxxxxxxxxxx>
---
drivers/md/raid5-ppl.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index 56b234683ee6..650bd59ead72 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -553,15 +553,13 @@ static void ppl_io_unit_finished(struct ppl_io_unit *io)
pr_debug("%s: seq: %llu\n", __func__, io->seq);
- local_irq_save(flags);
-
- spin_lock(&log->io_list_lock);
+ spin_lock_irqsave(&log->io_list_lock, flags);
list_del(&io->log_sibling);
- spin_unlock(&log->io_list_lock);
+ spin_unlock_irqrestore(&log->io_list_lock, flags);
mempool_free(io, &ppl_conf->io_pool);
- spin_lock(&ppl_conf->no_mem_stripes_lock);
+ spin_lock_irqsave(&ppl_conf->no_mem_stripes_lock, flags);
Please notice, local_irq_save + spin_lock is the same as
spin_lock_irqsave, I don't think your changes have any functonal
chagnes.
Thanks,
Kuai
if (!list_empty(&ppl_conf->no_mem_stripes)) {
struct stripe_head *sh;
@@ -571,9 +569,7 @@ static void ppl_io_unit_finished(struct ppl_io_unit *io)
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
- spin_unlock(&ppl_conf->no_mem_stripes_lock);
-
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&ppl_conf->no_mem_stripes_lock, flags);
wake_up(&conf->wait_for_quiescent);
}
