fs: dcache per-inode inode alias locking

dcache_inode_lock can be replaced with per-inode locking. Use existing
inode->i_lock for this. This is slightly non-trivial because we sometimes
need to find the inode from the dentry, which requires d_inode to be
stabilised (either with refcount or d_lock).

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index c3a5a1126833..5596c6a2881e 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -63,11 +63,11 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
                  * This again causes shrink_dcache_for_umount_subtree() to
                  * Oops, since the test for IS_ROOT() will fail.
                  */
-                spin_lock(&dcache_inode_lock);
+                spin_lock(&sb->s_root->d_inode->i_lock);
                 spin_lock(&sb->s_root->d_lock);
                 list_del_init(&sb->s_root->d_alias);
                 spin_unlock(&sb->s_root->d_lock);
-                spin_unlock(&dcache_inode_lock);
+                spin_unlock(&sb->s_root->d_inode->i_lock);
         }
         return 0;
 }