Driver use spin lock without irqsave when it needs to acquire
a chain frame to protect chain frame allocation from multiple
submission threads. If there is any I/O queued from an interrupt
context and if that requires a chain frame and if the chain lock
is held by the CPU which got interrupted then there will
be a possible deadlock.
Signed-off-by: Ranjan Kumar <ranjan.kumar@xxxxxxxxxxxx>
---
drivers/scsi/mpi3mr/mpi3mr_os.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c
index 6d55698ea4d1..ee6af3d4d667 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_os.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_os.c
@@ -3311,19 +3311,19 @@ static int mpi3mr_get_chain_idx(struct mpi3mr_ioc *mrioc)
{
u8 retry_count = 5;
int cmd_idx = -1;
+ unsigned long flags;
+ spin_lock_irqsave(&mrioc->chain_buf_lock, flags);
do {
- spin_lock(&mrioc->chain_buf_lock);
cmd_idx = find_first_zero_bit(mrioc->chain_bitmap,
mrioc->chain_buf_count);
if (cmd_idx < mrioc->chain_buf_count) {
set_bit(cmd_idx, mrioc->chain_bitmap);
- spin_unlock(&mrioc->chain_buf_lock);
break;
}
- spin_unlock(&mrioc->chain_buf_lock);
cmd_idx = -1;
} while (retry_count--);
+ spin_unlock_irqrestore(&mrioc->chain_buf_lock, flags);
return cmd_idx;
}
--
2.31.1
Attachment:
smime.p7s
Description: S/MIME Cryptographic Signature
