[dpdk-dev] [PATCH v2] fbarray: fix attach deadlock

[Darek Stojaczyk]

rte_fbarray_attach() currently locks its internal
spinlock, but never releases it. Secondary processes
won't even start if there is more than one fbarray
to be attached to - the second rte_fbarray_attach()
would be just stuck.

Fix it by releasing the lock at the end of
rte_fbarray_attach(). I believe this was the original
intention.

Fixes: 5b61c62cfd76 ("fbarray: add internal tailq for mapped areas")
Cc: anatoly.burakov at intel.com
Cc: thomas at monjalon.net

Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk at intel.com>
Reviewed-by: Gavin Hu <gavin.hu at arm.com>
---
v2:
 - fixed one more case where we could unlock the spinlock
   before locking it


 lib/librte_eal/common/eal_common_fbarray.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_fbarray.c b/lib/librte_eal/common/eal_common_fbarray.c
index 0e7366e5e..31cce80a8 100644
--- a/lib/librte_eal/common/eal_common_fbarray.c
+++ b/lib/librte_eal/common/eal_common_fbarray.c
@@ -859,8 +859,10 @@ rte_fbarray_attach(struct rte_fbarray *arr)
 	}
 
 	page_sz = sysconf(_SC_PAGESIZE);
-	if (page_sz == (size_t)-1)
-		goto fail;
+	if (page_sz == (size_t)-1) {
+		free(ma);
+		return -1;
+	}
 
 	mmap_len = calc_data_size(page_sz, arr->elt_sz, arr->len);
 
@@ -906,6 +908,7 @@ rte_fbarray_attach(struct rte_fbarray *arr)
 
 	/* we're done */
 
+	rte_spinlock_unlock(&mem_area_lock);
 	return 0;
 fail:
 	if (data)
@@ -913,6 +916,7 @@ rte_fbarray_attach(struct rte_fbarray *arr)
 	if (fd >= 0)
 		close(fd);
 	free(ma);
+	rte_spinlock_unlock(&mem_area_lock);
 	return -1;
 }
 
-- 
2.17.1