1 files changed, 25 insertions, 20 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index aac41adf4743..c435398f2c81 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * fs/dcache.c
  *
@@ -18,6 +19,7 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
+#include <linux/fscrypt.h>
 #include <linux/fsnotify.h>
 #include <linux/slab.h>
 #include <linux/init.h>
@@ -284,25 +286,23 @@ 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);
 	}
@@ -344,7 +344,7 @@ static void dentry_free(struct dentry *dentry)
 		}
 	}
 	/* if dentry was never visible to RCU, immediate free is OK */
-	if (!(dentry->d_flags & DCACHE_RCUACCESS))
+	if (dentry->d_flags & DCACHE_NORCU)
 		__d_free(&dentry->d_u.d_rcu);
 	else
 		call_rcu(&dentry->d_u.d_rcu, __d_free);
@@ -1701,7 +1701,6 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 	struct dentry *dentry = __d_alloc(parent->d_sb, name);
 	if (!dentry)
 		return NULL;
-	dentry->d_flags |= DCACHE_RCUACCESS;
 	spin_lock(&parent->d_lock);
 	/*
 	 * don't need child lock because it is not subject
@@ -1726,7 +1725,7 @@ struct dentry *d_alloc_cursor(struct dentry * parent)
 {
 	struct dentry *dentry = d_alloc_anon(parent->d_sb);
 	if (dentry) {
-		dentry->d_flags |= DCACHE_RCUACCESS | DCACHE_DENTRY_CURSOR;
+		dentry->d_flags |= DCACHE_DENTRY_CURSOR;
 		dentry->d_parent = dget(parent);
 	}
 	return dentry;
@@ -1739,12 +1738,21 @@ struct dentry *d_alloc_cursor(struct dentry * parent)
  *
  * For a filesystem that just pins its dentries in memory and never
  * performs lookups at all, return an unhashed IS_ROOT dentry.
+ * This is used for pipes, sockets et.al. - the stuff that should
+ * 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)
 {
-	return __d_alloc(sb, name);
+	struct dentry *dentry = __d_alloc(sb, name);
+	if (likely(dentry))
+		dentry->d_flags |= DCACHE_NORCU;
+	return dentry;
 }
-EXPORT_SYMBOL(d_alloc_pseudo);
 
 struct dentry *d_alloc_name(struct dentry *parent, const char *name)
 {
@@ -1911,12 +1919,10 @@ struct dentry *d_make_root(struct inode *root_inode)
 
 	if (root_inode) {
 		res = d_alloc_anon(root_inode->i_sb);
-		if (res) {
-			res->d_flags |= DCACHE_RCUACCESS;
+		if (res)
 			d_instantiate(res, root_inode);
-		} else {
+		else
 			iput(root_inode);
-		}
 	}
 	return res;
 }
@@ -2781,9 +2787,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
 		copy_name(dentry, target);
 		target->d_hash.pprev = NULL;
 		dentry->d_parent->d_lockref.count++;
-		if (dentry == old_parent)
-			dentry->d_flags |= DCACHE_RCUACCESS;
-		else
+		if (dentry != old_parent) /* wasn't IS_ROOT */
 			WARN_ON(!--old_parent->d_lockref.count);
 	} else {
 		target->d_parent = old_parent;
@@ -2795,6 +2799,7 @@ static void __d_move(struct dentry *dentry, struct dentry *target,
 	list_move(&dentry->d_child, &dentry->d_parent->d_subdirs);
 	__d_rehash(dentry);
 	fsnotify_update_flags(dentry);
+	fscrypt_handle_d_move(dentry);
 
 	write_seqcount_end(&target->d_seq);
 	write_seqcount_end(&dentry->d_seq);