Merge branch 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc dcache updates from Al Viro:
 "Most of this pile is putting name length into struct name_snapshot and
  making use of it.

  The beginning of this series ("ovl_lookup_real_one(): don't bother
  with strlen()") ought to have been split in two (separate switch of
  name_snapshot to struct qstr from overlayfs reaping the trivial
  benefits of that), but I wanted to avoid a rebase - by the time I'd
  spotted that it was (a) in -next and (b) close to 5.1-final ;-/"

* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit_compare_dname_path(): switch to const struct qstr *
  audit_update_watch(): switch to const struct qstr *
  inotify_handle_event(): don't bother with strlen()
  fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
  fsnotify(): switch to passing const struct qstr * for file_name
  switch fsnotify_move() to passing const struct qstr * for old_name
  ovl_lookup_real_one(): don't bother with strlen()
  sysv: bury the broken "quietly truncate the long filenames" logics
  nsfs: unobfuscate
  unexport d_alloc_pseudo()

Author: torvalds

Documentation/filesystems/porting

@@ -668,3 +668,8 @@ in your dentry operations instead.
 	DCACHE_RCUACCESS is gone; having an RCU delay on dentry freeing is the
 	default.  DCACHE_NORCU opts out, and only d_alloc_pseudo() has any
 	business doing so.
+--
+[mandatory]
+	d_alloc_pseudo() is internal-only; uses outside of alloc_file_pseudo() are
+	very suspect (and won't work in modules).  Such uses are very likely to
+	be misspelled d_alloc_anon().

fs/dcache.c

@@ -284,25 +284,23 @@ static inline int dname_external(const struct dentry *dentry)
 void take_dentry_name_snapshot(struct name_snapshot *name, struct dentry *dentry)
 {
 	spin_lock(&dentry->d_lock);
+	name->name = dentry->d_name;
 	if (unlikely(dname_external(dentry))) {
-		struct external_name *p = external_name(dentry);
-		atomic_inc(&p->u.count);
-		spin_unlock(&dentry->d_lock);
-		name->name = p->name;
+		atomic_inc(&external_name(dentry)->u.count);
 	} else {
 		memcpy(name->inline_name, dentry->d_iname,
 		       dentry->d_name.len + 1);
-		spin_unlock(&dentry->d_lock);
-		name->name = name->inline_name;
+		name->name.name = name->inline_name;
 	}
+	spin_unlock(&dentry->d_lock);
 }
 EXPORT_SYMBOL(take_dentry_name_snapshot);
 
 void release_dentry_name_snapshot(struct name_snapshot *name)
 {
-	if (unlikely(name->name != name->inline_name)) {
+	if (unlikely(name->name.name != name->inline_name)) {
 		struct external_name *p;
-		p = container_of(name->name, struct external_name, name[0]);
+		p = container_of(name->name.name, struct external_name, name[0]);
 		if (unlikely(atomic_dec_and_test(&p->u.count)))
 			kfree_rcu(p, u.head);
 	}
@@ -1742,6 +1740,9 @@ struct dentry *d_alloc_cursor(struct dentry * parent)
  * never be anyone's children or parents.  Unlike all other
  * dentries, these will not have RCU delay between dropping the
  * last reference and freeing them.
+ *
+ * The only user is alloc_file_pseudo() and that's what should
+ * be considered a public interface.  Don't use directly.
  */
 struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
 {
@@ -1750,7 +1751,6 @@ struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name)
 		dentry->d_flags |= DCACHE_NORCU;
 	return dentry;
 }
-EXPORT_SYMBOL(d_alloc_pseudo);
 
 struct dentry *d_alloc_name(struct dentry *parent, const char *name)
 {

fs/debugfs/inode.c

@@ -818,7 +818,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 		goto exit;
 	}
 	d_move(old_dentry, dentry);
-	fsnotify_move(d_inode(old_dir), d_inode(new_dir), old_name.name,
+	fsnotify_move(d_inode(old_dir), d_inode(new_dir), &old_name.name,
 		d_is_dir(old_dentry),
 		NULL, old_dentry);
 	release_dentry_name_snapshot(&old_name);

fs/internal.h

@@ -155,6 +155,7 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
 extern int d_set_mounted(struct dentry *dentry);
 extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
 extern struct dentry *d_alloc_cursor(struct dentry *);
+extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
 
 /*
  * read_write.c

fs/kernfs/file.c

@@ -885,6 +885,7 @@ static void kernfs_notify_workfn(struct work_struct *work)
 	list_for_each_entry(info, &kernfs_root(kn)->supers, node) {
 		struct kernfs_node *parent;
 		struct inode *inode;
+		struct qstr name;
 
 		/*
 		 * We want fsnotify_modify() on @kn but as the
@@ -896,22 +897,23 @@ static void kernfs_notify_workfn(struct work_struct *work)
 		if (!inode)
 			continue;
 
+		name = (struct qstr)QSTR_INIT(kn->name, strlen(kn->name));
 		parent = kernfs_get_parent(kn);
 		if (parent) {
 			struct inode *p_inode;
 
 			p_inode = ilookup(info->sb, parent->id.ino);
 			if (p_inode) {
 				fsnotify(p_inode, FS_MODIFY | FS_EVENT_ON_CHILD,
-					 inode, FSNOTIFY_EVENT_INODE, kn->name, 0);
+					 inode, FSNOTIFY_EVENT_INODE, &name, 0);
 				iput(p_inode);
 			}
 
 			kernfs_put(parent);
 		}
 
 		fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE,
-			 kn->name, 0);
+			 &name, 0);
 		iput(inode);
 	}
 

fs/namei.c

@@ -4498,10 +4498,10 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 		inode_unlock(target);
 	dput(new_dentry);
 	if (!error) {
-		fsnotify_move(old_dir, new_dir, old_name.name, is_dir,
+		fsnotify_move(old_dir, new_dir, &old_name.name, is_dir,
 			      !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
 		if (flags & RENAME_EXCHANGE) {
-			fsnotify_move(new_dir, old_dir, old_dentry->d_name.name,
+			fsnotify_move(new_dir, old_dir, &old_dentry->d_name,
 				      new_is_dir, NULL, new_dentry);
 		}
 	}

fs/notify/dnotify/dnotify.c

@@ -81,7 +81,7 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark *fsn_mark)
 static int dnotify_handle_event(struct fsnotify_group *group,
 				struct inode *inode,
 				u32 mask, const void *data, int data_type,
-				const unsigned char *file_name, u32 cookie,
+				const struct qstr *file_name, u32 cookie,
 				struct fsnotify_iter_info *iter_info)
 {
 	struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);

fs/notify/fanotify/fanotify.c

@@ -367,7 +367,7 @@ static __kernel_fsid_t fanotify_get_fsid(struct fsnotify_iter_info *iter_info)
 static int fanotify_handle_event(struct fsnotify_group *group,
 				 struct inode *inode,
 				 u32 mask, const void *data, int data_type,
-				 const unsigned char *file_name, u32 cookie,
+				 const struct qstr *file_name, u32 cookie,
 				 struct fsnotify_iter_info *iter_info)
 {
 	int ret = 0;

fs/notify/fsnotify.c

@@ -179,10 +179,10 @@ int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask
 		take_dentry_name_snapshot(&name, dentry);
 		if (path)
 			ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
-				       name.name, 0);
+				       &name.name, 0);
 		else
 			ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
-				       name.name, 0);
+				       &name.name, 0);
 		release_dentry_name_snapshot(&name);
 	}
 
@@ -195,7 +195,7 @@ EXPORT_SYMBOL_GPL(__fsnotify_parent);
 static int send_to_group(struct inode *to_tell,
 			 __u32 mask, const void *data,
 			 int data_is, u32 cookie,
-			 const unsigned char *file_name,
+			 const struct qstr *file_name,
 			 struct fsnotify_iter_info *iter_info)
 {
 	struct fsnotify_group *group = NULL;
@@ -325,7 +325,7 @@ static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
  * notification event in whatever means they feel necessary.
  */
 int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
-	     const unsigned char *file_name, u32 cookie)
+	     const struct qstr *file_name, u32 cookie)
 {
 	struct fsnotify_iter_info iter_info = {};
 	struct super_block *sb = to_tell->i_sb;

fs/notify/inotify/inotify.h

@@ -27,7 +27,7 @@ extern void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
 extern int inotify_handle_event(struct fsnotify_group *group,
 				struct inode *inode,
 				u32 mask, const void *data, int data_type,
-				const unsigned char *file_name, u32 cookie,
+				const struct qstr *file_name, u32 cookie,
 				struct fsnotify_iter_info *iter_info);
 
 extern const struct fsnotify_ops inotify_fsnotify_ops;