[PATCH 06/62] dma-buf: Handle all dma_resv_lock() errors

[Bart Van Assche <bart.vanassche@linux.dev>]

From: Bart Van Assche <bvanassche@acm.org>

Instead of assuming that dma_resv_lock() only returns 0 or -EDEADLK,
handle all possible dma_resv_lock() return values. This patch prepares
for enabling compile-time thread-safety analysis. This will cause the
compiler to check whether all dma_resv_lock() return values are handled.

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: linux-media@vger.kernel.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/dma-buf/dma-resv.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index bea3e9858aca..b4710f730e9b 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -792,6 +792,8 @@ static int __init dma_resv_lockdep(void)
 	ret = dma_resv_lock(&obj, &ctx);
 	if (ret == -EDEADLK)
 		dma_resv_lock_slow(&obj, &ctx);
+	else if (ret)
+		goto fini;
 	fs_reclaim_acquire(GFP_KERNEL);
 	/* for unmap_mapping_range on trylocked buffer objects in shrinkers */
 	i_mmap_lock_write(&mapping);
@@ -805,12 +807,14 @@ static int __init dma_resv_lockdep(void)
 #endif
 	fs_reclaim_release(GFP_KERNEL);
 	ww_mutex_unlock(&obj.lock);
+
+fini:
 	ww_acquire_fini(&ctx);
 	mmap_read_unlock(mm);
 
 	mmput(mm);
 
-	return 0;
+	return ret;
 }
 subsys_initcall(dma_resv_lockdep);
 #endif