ecryptfs: Fix refcnt leak on ecryptfs_follow_link() error path
[safe/jmp/linux-2.6] / fs / debugfs / inode.c
index 9c51a9f..b486169 100644 (file)
 #include <linux/debugfs.h>
 #include <linux/fsnotify.h>
 #include <linux/string.h>
-
-#define DEBUGFS_MAGIC  0x64626720
-
-/* declared over in file.c */
-extern struct file_operations debugfs_file_operations;
-extern struct inode_operations debugfs_link_operations;
+#include <linux/magic.h>
 
 static struct vfsmount *debugfs_mount;
 static int debugfs_mount_count;
+static bool debugfs_registered;
+
+static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev,
+                                      void *data, const struct file_operations *fops)
 
-static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev)
 {
        struct inode *inode = new_inode(sb);
 
        if (inode) {
                inode->i_mode = mode;
-               inode->i_uid = 0;
-               inode->i_gid = 0;
-               inode->i_blocks = 0;
                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
                switch (mode & S_IFMT) {
                default:
                        init_special_inode(inode, mode, dev);
                        break;
                case S_IFREG:
-                       inode->i_fop = &debugfs_file_operations;
+                       inode->i_fop = fops ? fops : &debugfs_file_operations;
+                       inode->i_private = data;
                        break;
                case S_IFLNK:
                        inode->i_op = &debugfs_link_operations;
+                       inode->i_fop = fops;
+                       inode->i_private = data;
                        break;
                case S_IFDIR:
                        inode->i_op = &simple_dir_inode_operations;
-                       inode->i_fop = &simple_dir_operations;
+                       inode->i_fop = fops ? fops : &simple_dir_operations;
+                       inode->i_private = data;
 
                        /* directory inodes start off with i_nlink == 2
                         * (for "." entry) */
@@ -71,7 +70,8 @@ static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t d
 
 /* SMP-safe */
 static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
-                        int mode, dev_t dev)
+                        int mode, dev_t dev, void *data,
+                        const struct file_operations *fops)
 {
        struct inode *inode;
        int error = -EPERM;
@@ -79,7 +79,7 @@ static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
        if (dentry->d_inode)
                return -EEXIST;
 
-       inode = debugfs_get_inode(dir->i_sb, mode, dev);
+       inode = debugfs_get_inode(dir->i_sb, mode, dev, data, fops);
        if (inode) {
                d_instantiate(dentry, inode);
                dget(dentry);
@@ -88,12 +88,13 @@ static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
        return error;
 }
 
-static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode,
+                        void *data, const struct file_operations *fops)
 {
        int res;
 
        mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
-       res = debugfs_mknod(dir, dentry, mode, 0);
+       res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
        if (!res) {
                inc_nlink(dir);
                fsnotify_mkdir(dir, dentry);
@@ -101,18 +102,20 @@ static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
        return res;
 }
 
-static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode)
+static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode,
+                       void *data, const struct file_operations *fops)
 {
        mode = (mode & S_IALLUGO) | S_IFLNK;
-       return debugfs_mknod(dir, dentry, mode, 0);
+       return debugfs_mknod(dir, dentry, mode, 0, data, fops);
 }
 
-static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode)
+static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode,
+                         void *data, const struct file_operations *fops)
 {
        int res;
 
        mode = (mode & S_IALLUGO) | S_IFREG;
-       res = debugfs_mknod(dir, dentry, mode, 0);
+       res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
        if (!res)
                fsnotify_create(dir, dentry);
        return res;
@@ -146,7 +149,9 @@ static struct file_system_type debug_fs_type = {
 
 static int debugfs_create_by_name(const char *name, mode_t mode,
                                  struct dentry *parent,
-                                 struct dentry **dentry)
+                                 struct dentry **dentry,
+                                 void *data,
+                                 const struct file_operations *fops)
 {
        int error = 0;
 
@@ -171,13 +176,16 @@ static int debugfs_create_by_name(const char *name, mode_t mode,
        if (!IS_ERR(*dentry)) {
                switch (mode & S_IFMT) {
                case S_IFDIR:
-                       error = debugfs_mkdir(parent->d_inode, *dentry, mode);
+                       error = debugfs_mkdir(parent->d_inode, *dentry, mode,
+                                             data, fops);
                        break;
                case S_IFLNK:
-                       error = debugfs_link(parent->d_inode, *dentry, mode);
+                       error = debugfs_link(parent->d_inode, *dentry, mode,
+                                            data, fops);
                        break;
                default:
-                       error = debugfs_create(parent->d_inode, *dentry, mode);
+                       error = debugfs_create(parent->d_inode, *dentry, mode,
+                                              data, fops);
                        break;
                }
                dput(*dentry);
@@ -191,7 +199,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode,
 /**
  * debugfs_create_file - create a file in the debugfs filesystem
  * @name: a pointer to a string containing the name of the file to create.
- * @mode: the permission that the file should have
+ * @mode: the permission that the file should have.
  * @parent: a pointer to the parent dentry for this file.  This should be a
  *          directory dentry if set.  If this paramater is NULL, then the
  *          file will be created in the root of the debugfs filesystem.
@@ -202,8 +210,8 @@ static int debugfs_create_by_name(const char *name, mode_t mode,
  *        this file.
  *
  * This is the basic "create a file" function for debugfs.  It allows for a
- * wide range of flexibility in createing a file, or a directory (if you
- * want to create a directory, the debugfs_create_dir() function is
+ * wide range of flexibility in creating a file, or a directory (if you want
+ * to create a directory, the debugfs_create_dir() function is
  * recommended to be used instead.)
  *
  * This function will return a pointer to a dentry if it succeeds.  This
@@ -212,9 +220,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode,
  * you are responsible here.)  If an error occurs, %NULL will be returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
- * returned.  It is not wise to check for this value, but rather, check for
- * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
- * code.
+ * returned.
  */
 struct dentry *debugfs_create_file(const char *name, mode_t mode,
                                   struct dentry *parent, void *data,
@@ -230,19 +236,13 @@ struct dentry *debugfs_create_file(const char *name, mode_t mode,
        if (error)
                goto exit;
 
-       error = debugfs_create_by_name(name, mode, parent, &dentry);
+       error = debugfs_create_by_name(name, mode, parent, &dentry,
+                                      data, fops);
        if (error) {
                dentry = NULL;
                simple_release_fs(&debugfs_mount, &debugfs_mount_count);
                goto exit;
        }
-
-       if (dentry->d_inode) {
-               if (data)
-                       dentry->d_inode->i_private = data;
-               if (fops)
-                       dentry->d_inode->i_fop = fops;
-       }
 exit:
        return dentry;
 }
@@ -264,9 +264,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file);
  * you are responsible here.)  If an error occurs, %NULL will be returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
- * returned.  It is not wise to check for this value, but rather, check for
- * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
- * code.
+ * returned.
  */
 struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 {
@@ -297,9 +295,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir);
  * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
- * returned.  It is not wise to check for this value, but rather, check for
- * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling
- * code.
+ * returned.
  */
 struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
                                      const char *target)
@@ -319,6 +315,31 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_symlink);
 
+static void __debugfs_remove(struct dentry *dentry, struct dentry *parent)
+{
+       int ret = 0;
+
+       if (debugfs_positive(dentry)) {
+               if (dentry->d_inode) {
+                       dget(dentry);
+                       switch (dentry->d_inode->i_mode & S_IFMT) {
+                       case S_IFDIR:
+                               ret = simple_rmdir(parent->d_inode, dentry);
+                               break;
+                       case S_IFLNK:
+                               kfree(dentry->d_inode->i_private);
+                               /* fall through */
+                       default:
+                               simple_unlink(parent->d_inode, dentry);
+                               break;
+                       }
+                       if (!ret)
+                               d_delete(dentry);
+                       dput(dentry);
+               }
+       }
+}
+
 /**
  * debugfs_remove - removes a file or directory from the debugfs filesystem
  * @dentry: a pointer to a the dentry of the file or directory to be
@@ -335,7 +356,6 @@ EXPORT_SYMBOL_GPL(debugfs_create_symlink);
 void debugfs_remove(struct dentry *dentry)
 {
        struct dentry *parent;
-       int ret = 0;
        
        if (!dentry)
                return;
@@ -345,57 +365,194 @@ void debugfs_remove(struct dentry *dentry)
                return;
 
        mutex_lock(&parent->d_inode->i_mutex);
-       if (debugfs_positive(dentry)) {
-               if (dentry->d_inode) {
-                       dget(dentry);
-                       switch (dentry->d_inode->i_mode & S_IFMT) {
-                       case S_IFDIR:
-                               ret = simple_rmdir(parent->d_inode, dentry);
-                               if (ret)
-                                       printk(KERN_ERR
-                                               "DebugFS rmdir on %s failed : "
-                                               "directory not empty.\n",
-                                               dentry->d_name.name);
-                               break;
-                       case S_IFLNK:
-                               kfree(dentry->d_inode->i_private);
-                               /* fall through */
-                       default:
-                               simple_unlink(parent->d_inode, dentry);
+       __debugfs_remove(dentry, parent);
+       mutex_unlock(&parent->d_inode->i_mutex);
+       simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+}
+EXPORT_SYMBOL_GPL(debugfs_remove);
+
+/**
+ * debugfs_remove_recursive - recursively removes a directory
+ * @dentry: a pointer to a the dentry of the directory to be removed.
+ *
+ * This function recursively removes a directory tree in debugfs that
+ * was previously created with a call to another debugfs function
+ * (like debugfs_create_file() or variants thereof.)
+ *
+ * This function is required to be called in order for the file to be
+ * removed, no automatic cleanup of files will happen when a module is
+ * removed, you are responsible here.
+ */
+void debugfs_remove_recursive(struct dentry *dentry)
+{
+       struct dentry *child;
+       struct dentry *parent;
+
+       if (!dentry)
+               return;
+
+       parent = dentry->d_parent;
+       if (!parent || !parent->d_inode)
+               return;
+
+       parent = dentry;
+       mutex_lock(&parent->d_inode->i_mutex);
+
+       while (1) {
+               /*
+                * When all dentries under "parent" has been removed,
+                * walk up the tree until we reach our starting point.
+                */
+               if (list_empty(&parent->d_subdirs)) {
+                       mutex_unlock(&parent->d_inode->i_mutex);
+                       if (parent == dentry)
                                break;
+                       parent = parent->d_parent;
+                       mutex_lock(&parent->d_inode->i_mutex);
+               }
+               child = list_entry(parent->d_subdirs.next, struct dentry,
+                               d_u.d_child);
+ next_sibling:
+
+               /*
+                * If "child" isn't empty, walk down the tree and
+                * remove all its descendants first.
+                */
+               if (!list_empty(&child->d_subdirs)) {
+                       mutex_unlock(&parent->d_inode->i_mutex);
+                       parent = child;
+                       mutex_lock(&parent->d_inode->i_mutex);
+                       continue;
+               }
+               __debugfs_remove(child, parent);
+               if (parent->d_subdirs.next == &child->d_u.d_child) {
+                       /*
+                        * Try the next sibling.
+                        */
+                       if (child->d_u.d_child.next != &parent->d_subdirs) {
+                               child = list_entry(child->d_u.d_child.next,
+                                                  struct dentry,
+                                                  d_u.d_child);
+                               goto next_sibling;
                        }
-                       if (!ret)
-                               d_delete(dentry);
-                       dput(dentry);
+
+                       /*
+                        * Avoid infinite loop if we fail to remove
+                        * one dentry.
+                        */
+                       mutex_unlock(&parent->d_inode->i_mutex);
+                       break;
                }
+               simple_release_fs(&debugfs_mount, &debugfs_mount_count);
        }
+
+       parent = dentry->d_parent;
+       mutex_lock(&parent->d_inode->i_mutex);
+       __debugfs_remove(dentry, parent);
        mutex_unlock(&parent->d_inode->i_mutex);
        simple_release_fs(&debugfs_mount, &debugfs_mount_count);
 }
-EXPORT_SYMBOL_GPL(debugfs_remove);
+EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
+
+/**
+ * debugfs_rename - rename a file/directory in the debugfs filesystem
+ * @old_dir: a pointer to the parent dentry for the renamed object. This
+ *          should be a directory dentry.
+ * @old_dentry: dentry of an object to be renamed.
+ * @new_dir: a pointer to the parent dentry where the object should be
+ *          moved. This should be a directory dentry.
+ * @new_name: a pointer to a string containing the target name.
+ *
+ * This function renames a file/directory in debugfs.  The target must not
+ * exist for rename to succeed.
+ *
+ * This function will return a pointer to old_dentry (which is updated to
+ * reflect renaming) if it succeeds. If an error occurs, %NULL will be
+ * returned.
+ *
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
+ * returned.
+ */
+struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
+               struct dentry *new_dir, const char *new_name)
+{
+       int error;
+       struct dentry *dentry = NULL, *trap;
+       const char *old_name;
+
+       trap = lock_rename(new_dir, old_dir);
+       /* Source or destination directories don't exist? */
+       if (!old_dir->d_inode || !new_dir->d_inode)
+               goto exit;
+       /* Source does not exist, cyclic rename, or mountpoint? */
+       if (!old_dentry->d_inode || old_dentry == trap ||
+           d_mountpoint(old_dentry))
+               goto exit;
+       dentry = lookup_one_len(new_name, new_dir, strlen(new_name));
+       /* Lookup failed, cyclic rename or target exists? */
+       if (IS_ERR(dentry) || dentry == trap || dentry->d_inode)
+               goto exit;
+
+       old_name = fsnotify_oldname_init(old_dentry->d_name.name);
+
+       error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode,
+               dentry);
+       if (error) {
+               fsnotify_oldname_free(old_name);
+               goto exit;
+       }
+       d_move(old_dentry, dentry);
+       fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name,
+               old_dentry->d_name.name, S_ISDIR(old_dentry->d_inode->i_mode),
+               NULL, old_dentry);
+       fsnotify_oldname_free(old_name);
+       unlock_rename(new_dir, old_dir);
+       dput(dentry);
+       return old_dentry;
+exit:
+       if (dentry && !IS_ERR(dentry))
+               dput(dentry);
+       unlock_rename(new_dir, old_dir);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(debugfs_rename);
+
+/**
+ * debugfs_initialized - Tells whether debugfs has been registered
+ */
+bool debugfs_initialized(void)
+{
+       return debugfs_registered;
+}
+EXPORT_SYMBOL_GPL(debugfs_initialized);
+
 
-static decl_subsys(debug, NULL, NULL);
+static struct kobject *debug_kobj;
 
 static int __init debugfs_init(void)
 {
        int retval;
 
-       kset_set_kset_s(&debug_subsys, kernel_subsys);
-       retval = subsystem_register(&debug_subsys);
-       if (retval)
-               return retval;
+       debug_kobj = kobject_create_and_add("debug", kernel_kobj);
+       if (!debug_kobj)
+               return -EINVAL;
 
        retval = register_filesystem(&debug_fs_type);
        if (retval)
-               subsystem_unregister(&debug_subsys);
+               kobject_put(debug_kobj);
+       else
+               debugfs_registered = true;
+
        return retval;
 }
 
 static void __exit debugfs_exit(void)
 {
+       debugfs_registered = false;
+
        simple_release_fs(&debugfs_mount, &debugfs_mount_count);
        unregister_filesystem(&debug_fs_type);
-       subsystem_unregister(&debug_subsys);
+       kobject_put(debug_kobj);
 }
 
 core_initcall(debugfs_init);