sysfs: reorganize sysfs_new_indoe() and sysfs_create()

Reorganize/clean up sysfs_new_inode() and sysfs_create().

* sysfs_init_inode() is separated out from sysfs_new_inode() and is
  responsible for basic initialization.
* sysfs_instantiate() replaces the last step of sysfs_create() and is
  responsible for dentry instantitaion.
* type-specific initialization is moved out to the callers.
* mode is specified only once when creating a sysfs_dirent.
* spurious list_del_init(&sd->s_sibling) dropped from create_dir()

This change is to

* prepare for inode allocation fix.
* separate alloc and init code for synchronization update.
* make dentry/inode initialization more flexible for later changes.

This patch doesn't introduce visible behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 57 insertions, 51 deletions

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 6ad47c13b94d..26d8503c8997 100644
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -133,62 +133,68 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
  */
 static struct lock_class_key sysfs_inode_imutex_key;
 
-struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd)
+void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
 {
-        struct inode * inode = new_inode(sysfs_sb);
-        if (inode) {
-                inode->i_blocks = 0;
-                inode->i_mapping->a_ops = &sysfs_aops;
-                inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
-                inode->i_op = &sysfs_inode_operations;
-                inode->i_ino = sd->s_ino;
-                lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
-
-                if (sd->s_iattr) {
-                        /* sysfs_dirent has non-default attributes
-                         * get them for the new inode from persistent copy
-                         * in sysfs_dirent
-                         */
-                        set_inode_attr(inode, sd->s_iattr);
-                } else
-                        set_default_inode_attr(inode, mode);
-        }
+        inode->i_blocks = 0;
+        inode->i_mapping->a_ops = &sysfs_aops;
+        inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
+        inode->i_op = &sysfs_inode_operations;
+        inode->i_ino = sd->s_ino;
+        lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
+
+        if (sd->s_iattr) {
+                /* sysfs_dirent has non-default attributes
+                 * get them for the new inode from persistent copy
+                 * in sysfs_dirent
+                 */
+                set_inode_attr(inode, sd->s_iattr);
+        } else
+                set_default_inode_attr(inode, sd->s_mode);
+}
+
+/**
+ *      sysfs_new_inode - allocate new inode for sysfs_dirent
+ *      @sd: sysfs_dirent to allocate inode for
+ *
+ *      Allocate inode for @sd and initialize basics.
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ *
+ *      RETURNS:
+ *      Pointer to allocated inode on success, NULL on failure.
+ */
+struct inode * sysfs_new_inode(struct sysfs_dirent *sd)
+{
+        struct inode *inode;
+
+        inode = new_inode(sysfs_sb);
+        if (inode)
+                sysfs_init_inode(sd, inode);
+
         return inode;
 }
 
-int sysfs_create(struct sysfs_dirent *sd, struct dentry *dentry, int mode,
-                 int (*init)(struct inode *))
+/**
+ *      sysfs_instantiate - instantiate dentry
+ *      @dentry: dentry to be instantiated
+ *      @inode: inode associated with @sd
+ *
+ *      Instantiate @dentry with @inode.
+ *
+ *      LOCKING:
+ *      None.
+ */
+void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
 {
-        int error = 0;
-        struct inode * inode = NULL;
-        if (dentry) {
-                if (!dentry->d_inode) {
-                        if ((inode = sysfs_new_inode(mode, sd))) {
-                                if (dentry->d_parent && dentry->d_parent->d_inode) {
-                                        struct inode *p_inode = dentry->d_parent->d_inode;
-                                        p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
-                                }
-                                goto Proceed;
-                        }
-                        else 
-                                error = -ENOMEM;
-                } else
-                        error = -EEXIST;
-        } else 
-                error = -ENOENT;
-        goto Done;
-
- Proceed:
-        if (init)
-                error = init(inode);
-        if (!error) {
-                d_instantiate(dentry, inode);
-                if (S_ISDIR(mode))
-                        dget(dentry);  /* pin only directory dentry in core */
-        } else
-                iput(inode);
- Done:
-        return error;
+        BUG_ON(!dentry || dentry->d_inode);
+
+        if (dentry->d_parent && dentry->d_parent->d_inode) {
+                struct inode *p_inode = dentry->d_parent->d_inode;
+                p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME;
+        }
+
+        d_instantiate(dentry, inode);
 }
 
 /**