From 7c5162a9236379f86a56b7e1d685c9e182a6aaab Mon Sep 17 00:00:00 2001 From: Yunseong Kim Date: Sun, 17 Aug 2025 11:31:16 +0000 Subject: [PATCH] md/raid5-ppl: Fix invalid context sleep in ppl_io_unit_finished() on PREEMPT_RT 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. 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 --- 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 c0fb335311aa..c74809db6f01 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); 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); }