[PATCH net v2 2/2] Revert "sockfs: switch to ->free_inode()"

[SeongJae Park]

From: SeongJae Park <sjpark@xxxxxxxxx>

This reverts commit 6d7855c54e1e269275d7c504f8f62a0b7a5b3f18.

The commit 6d7855c54e1e ("sockfs: switch to ->free_inode()") made the
deallocation of 'socket_alloc' to be done asynchronously using RCU, as
same to 'sock.wq'.

The change made 'socket_alloc' live longer than before.  As a result,
user programs intensively repeating allocations and deallocations of
sockets could cause memory pressure on recent kernels.

To avoid the problem, this commit reverts the change.

Fixes: 6d7855c54e1e ("sockfs: switch to ->free_inode()")
Fixes: 333f7909a857 ("coallocate socket_sq with socket itself")
Signed-off-by: SeongJae Park <sjpark@xxxxxxxxx>
---
 net/socket.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index e274ae4b45e4..27174021f47f 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -273,12 +273,12 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void sock_free_inode(struct inode *inode)
+static void sock_destroy_inode(struct inode *inode)
 {
 	struct socket_alloc *ei;
 
 	ei = container_of(inode, struct socket_alloc, vfs_inode);
-	kfree(ei->socket.wq);
+	kfree_rcu(ei->socket.wq, rcu);
 	kmem_cache_free(sock_inode_cachep, ei);
 }
 
@@ -303,7 +303,7 @@ static void init_inodecache(void)
 
 static const struct super_operations sockfs_ops = {
 	.alloc_inode	= sock_alloc_inode,
-	.free_inode	= sock_free_inode,
+	.destroy_inode	= sock_destroy_inode,
 	.statfs		= simple_statfs,
 };
 
-- 
2.17.1