sdcardfs: Fix locking for permission fix up

Iterating over d_subdirs requires taking d_lock.
Removed several unneeded locks.

Change-Id: I5b1588e54c7e6ee19b756d6705171c7f829e2650
Signed-off-by: Daniel Rosenberg <drosen@google.com>

3 files changed, 3 insertions, 9 deletions

diff --git a/fs/sdcardfs/derived_perm.c b/fs/sdcardfs/derived_perm.c
index 41e0e11b3..bfe402b8c 100755
--- a/fs/sdcardfs/derived_perm.c
+++ b/fs/sdcardfs/derived_perm.c
@@ -111,15 +111,15 @@ void get_derived_permission(struct dentry *parent, struct dentry *dentry)
 
 void get_derive_permissions_recursive(struct dentry *parent) {
 	struct dentry *dentry;
+	spin_lock(&parent->d_lock);
 	list_for_each_entry(dentry, &parent->d_subdirs, d_child) {
 		if (dentry->d_inode) {
-			mutex_lock(&dentry->d_inode->i_mutex);
 			get_derived_permission(parent, dentry);
 			fix_derived_permission(dentry->d_inode);
 			get_derive_permissions_recursive(dentry);
-			mutex_unlock(&dentry->d_inode->i_mutex);
 		}
 	}
+	spin_unlock(&parent->d_lock);
 }
 
 /* main function for updating derived permission */
@@ -135,7 +135,6 @@ inline void update_derived_permission_lock(struct dentry *dentry)
 	 * 1. need to check whether the dentry is updated or not
 	 * 2. remove the root dentry update
 	 */
-	mutex_lock(&dentry->d_inode->i_mutex);
 	if(IS_ROOT(dentry)) {
 		//setup_default_pre_root_state(dentry->d_inode);
 	} else {
@@ -146,7 +145,6 @@ inline void update_derived_permission_lock(struct dentry *dentry)
 		}
 	}
 	fix_derived_permission(dentry->d_inode);
-	mutex_unlock(&dentry->d_inode->i_mutex);
 }
 
 int need_graft_path(struct dentry *dentry)
diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
index 0b2abbfbf..a61e8c821 100755
--- a/fs/sdcardfs/inode.c
+++ b/fs/sdcardfs/inode.c
@@ -512,11 +512,9 @@ static int sdcardfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	}
 	/* At this point, not all dentry information has been moved, so
 	 * we pass along new_dentry for the name.*/
-	mutex_lock(&old_dentry->d_inode->i_mutex);
 	get_derived_permission_new(new_dentry->d_parent, old_dentry, new_dentry);
 	fix_derived_permission(old_dentry->d_inode);
 	get_derive_permissions_recursive(old_dentry);
-	mutex_unlock(&old_dentry->d_inode->i_mutex);
 out:
 	unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
 	dput(lower_old_dir_dentry);
diff --git a/fs/sdcardfs/lookup.c b/fs/sdcardfs/lookup.c
index b5b48e52d..e5a202bf9 100755
--- a/fs/sdcardfs/lookup.c
+++ b/fs/sdcardfs/lookup.c
@@ -392,11 +392,9 @@ struct dentry *sdcardfs_lookup(struct inode *dir, struct dentry *dentry,
 	if (dentry->d_inode) {
 		fsstack_copy_attr_times(dentry->d_inode,
 					sdcardfs_lower_inode(dentry->d_inode));
-		/* get drived permission */
-		mutex_lock(&dentry->d_inode->i_mutex);
+		/* get derived permission */
 		get_derived_permission(parent, dentry);
 		fix_derived_permission(dentry->d_inode);
-		mutex_unlock(&dentry->d_inode->i_mutex);
 	}
 	/* update parent directory's atime */
 	fsstack_copy_attr_atime(parent->d_inode,