configfs: Add permission and ownership to configfs objects.

configfs always made item and attribute ownership root.root and
permissions based on a umask of 022.  Add ->setattr() to allow
chown(2)/chmod(2), and persist the changes for the lifetime of the
items and attributes.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 26 insertions, 10 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index b668ec61527e..ca60e3abef45 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -72,7 +72,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare
 {
         struct configfs_dirent * sd;
 
-        sd = kmalloc(sizeof(*sd), GFP_KERNEL);
+        sd = kmem_cache_alloc(configfs_dir_cachep, GFP_KERNEL);
         if (!sd)
                 return NULL;
 
@@ -136,13 +136,19 @@ static int create_dir(struct config_item * k, struct dentry * p,
         int error;
         umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
 
-        error = configfs_create(d, mode, init_dir);
+        error = configfs_make_dirent(p->d_fsdata, d, k, mode,
+                                     CONFIGFS_DIR);
         if (!error) {
-                error = configfs_make_dirent(p->d_fsdata, d, k, mode,
-                                           CONFIGFS_DIR);
+                error = configfs_create(d, mode, init_dir);
                 if (!error) {
                         p->d_inode->i_nlink++;
                         (d)->d_op = &configfs_dentry_ops;
+                } else {
+                        struct configfs_dirent *sd = d->d_fsdata;
+                        if (sd) {
+                                list_del_init(&sd->s_sibling);
+                                configfs_put(sd);
+                        }
                 }
         }
         return error;
@@ -182,12 +188,19 @@ int configfs_create_link(struct configfs_symlink *sl,
         int err = 0;
         umode_t mode = S_IFLNK | S_IRWXUGO;
 
-        err = configfs_create(dentry, mode, init_symlink);
+        err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
+                                   CONFIGFS_ITEM_LINK);
         if (!err) {
-                err = configfs_make_dirent(parent->d_fsdata, dentry, sl,
-                                         mode, CONFIGFS_ITEM_LINK);
+                err = configfs_create(dentry, mode, init_symlink);
                 if (!err)
                         dentry->d_op = &configfs_dentry_ops;
+                else {
+                        struct configfs_dirent *sd = dentry->d_fsdata;
+                        if (sd) {
+                                list_del_init(&sd->s_sibling);
+                                configfs_put(sd);
+                        }
+                }
         }
         return err;
 }
@@ -241,13 +254,15 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den
         struct configfs_attribute * attr = sd->s_element;
         int error;
 
+        dentry->d_fsdata = configfs_get(sd);
+        sd->s_dentry = dentry;
         error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
-        if (error)
+        if (error) {
+                configfs_put(sd);
                 return error;
+        }
 
         dentry->d_op = &configfs_dentry_ops;
-        dentry->d_fsdata = configfs_get(sd);
-        sd->s_dentry = dentry;
         d_rehash(dentry);
 
         return 0;
@@ -839,6 +854,7 @@ struct inode_operations configfs_dir_inode_operations = {
         .symlink        = configfs_symlink,
         .unlink         = configfs_unlink,
         .lookup         = configfs_lookup,
+        .setattr        = configfs_setattr,
 };
 
 #if 0