Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
index 0caa151..8b7315c 100644
--- a/fs/tracefs/inode.c
+++ b/fs/tracefs/inode.c
@@ -159,6 +159,77 @@
 	struct tracefs_mount_opts mount_opts;
 };
 
+static void change_gid(struct dentry *dentry, kgid_t gid)
+{
+	if (!dentry->d_inode)
+		return;
+	dentry->d_inode->i_gid = gid;
+}
+
+/*
+ * Taken from d_walk, but without he need for handling renames.
+ * Nothing can be renamed while walking the list, as tracefs
+ * does not support renames. This is only called when mounting
+ * or remounting the file system, to set all the files to
+ * the given gid.
+ */
+static void set_gid(struct dentry *parent, kgid_t gid)
+{
+	struct dentry *this_parent;
+	struct list_head *next;
+
+	this_parent = parent;
+	spin_lock(&this_parent->d_lock);
+
+	change_gid(this_parent, gid);
+repeat:
+	next = this_parent->d_subdirs.next;
+resume:
+	while (next != &this_parent->d_subdirs) {
+		struct list_head *tmp = next;
+		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+		next = tmp->next;
+
+		spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+
+		change_gid(dentry, gid);
+
+		if (!list_empty(&dentry->d_subdirs)) {
+			spin_unlock(&this_parent->d_lock);
+			spin_release(&dentry->d_lock.dep_map, _RET_IP_);
+			this_parent = dentry;
+			spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_);
+			goto repeat;
+		}
+		spin_unlock(&dentry->d_lock);
+	}
+	/*
+	 * All done at this level ... ascend and resume the search.
+	 */
+	rcu_read_lock();
+ascend:
+	if (this_parent != parent) {
+		struct dentry *child = this_parent;
+		this_parent = child->d_parent;
+
+		spin_unlock(&child->d_lock);
+		spin_lock(&this_parent->d_lock);
+
+		/* go into the first sibling still alive */
+		do {
+			next = child->d_child.next;
+			if (next == &this_parent->d_subdirs)
+				goto ascend;
+			child = list_entry(next, struct dentry, d_child);
+		} while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED));
+		rcu_read_unlock();
+		goto resume;
+	}
+	rcu_read_unlock();
+	spin_unlock(&this_parent->d_lock);
+	return;
+}
+
 static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
 {
 	substring_t args[MAX_OPT_ARGS];
@@ -217,7 +288,9 @@
 	inode->i_mode |= opts->mode;
 
 	inode->i_uid = opts->uid;
-	inode->i_gid = opts->gid;
+
+	/* Set all the group ids to the mount option */
+	set_gid(sb->s_root, opts->gid);
 
 	return 0;
 }
@@ -330,7 +403,10 @@
 		parent = tracefs_mount->mnt_root;
 
 	inode_lock(parent->d_inode);
-	dentry = lookup_one_len(name, parent, strlen(name));
+	if (unlikely(IS_DEADDIR(parent->d_inode)))
+		dentry = ERR_PTR(-ENOENT);
+	else
+		dentry = lookup_one_len(name, parent, strlen(name));
 	if (!IS_ERR(dentry) && dentry->d_inode) {
 		dput(dentry);
 		dentry = ERR_PTR(-EEXIST);
@@ -409,6 +485,8 @@
 	inode->i_mode = mode;
 	inode->i_fop = fops ? fops : &tracefs_file_operations;
 	inode->i_private = data;
+	inode->i_uid = d_inode(dentry->d_parent)->i_uid;
+	inode->i_gid = d_inode(dentry->d_parent)->i_gid;
 	d_instantiate(dentry, inode);
 	fsnotify_create(dentry->d_parent->d_inode, dentry);
 	return end_creating(dentry);
@@ -427,9 +505,12 @@
 	if (unlikely(!inode))
 		return failed_creating(dentry);
 
-	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+	/* Do not set bits for OTH */
+	inode->i_mode = S_IFDIR | S_IRWXU | S_IRUSR| S_IRGRP | S_IXUSR | S_IXGRP;
 	inode->i_op = ops;
 	inode->i_fop = &simple_dir_operations;
+	inode->i_uid = d_inode(dentry->d_parent)->i_uid;
+	inode->i_gid = d_inode(dentry->d_parent)->i_gid;
 
 	/* directory inodes start off with i_nlink == 2 (for "." entry) */
 	inc_nlink(inode);
@@ -499,122 +580,27 @@
 	return dentry;
 }
 
-static int __tracefs_remove(struct dentry *dentry, struct dentry *parent)
+static void remove_one(struct dentry *victim)
 {
-	int ret = 0;
-
-	if (simple_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)
-					fsnotify_rmdir(parent->d_inode, dentry);
-				break;
-			default:
-				simple_unlink(parent->d_inode, dentry);
-				fsnotify_unlink(parent->d_inode, dentry);
-				break;
-			}
-			if (!ret)
-				d_delete(dentry);
-			dput(dentry);
-		}
-	}
-	return ret;
+	simple_release_fs(&tracefs_mount, &tracefs_mount_count);
 }
 
 /**
- * tracefs_remove - removes a file or directory from the tracefs filesystem
- * @dentry: a pointer to a the dentry of the file or directory to be
- *          removed.
- *
- * This function removes a file or directory in tracefs that was previously
- * created with a call to another tracefs function (like
- * tracefs_create_file() or variants thereof.)
- */
-void tracefs_remove(struct dentry *dentry)
-{
-	struct dentry *parent;
-	int ret;
-
-	if (IS_ERR_OR_NULL(dentry))
-		return;
-
-	parent = dentry->d_parent;
-	inode_lock(parent->d_inode);
-	ret = __tracefs_remove(dentry, parent);
-	inode_unlock(parent->d_inode);
-	if (!ret)
-		simple_release_fs(&tracefs_mount, &tracefs_mount_count);
-}
-
-/**
- * tracefs_remove_recursive - recursively removes a directory
+ * tracefs_remove - 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 tracefs that
  * was previously created with a call to another tracefs function
  * (like tracefs_create_file() or variants thereof.)
  */
-void tracefs_remove_recursive(struct dentry *dentry)
+void tracefs_remove(struct dentry *dentry)
 {
-	struct dentry *child, *parent;
-
 	if (IS_ERR_OR_NULL(dentry))
 		return;
 
-	parent = dentry;
- down:
-	inode_lock(parent->d_inode);
- loop:
-	/*
-	 * The parent->d_subdirs is protected by the d_lock. Outside that
-	 * lock, the child can be unlinked and set to be freed which can
-	 * use the d_u.d_child as the rcu head and corrupt this list.
-	 */
-	spin_lock(&parent->d_lock);
-	list_for_each_entry(child, &parent->d_subdirs, d_child) {
-		if (!simple_positive(child))
-			continue;
-
-		/* perhaps simple_empty(child) makes more sense */
-		if (!list_empty(&child->d_subdirs)) {
-			spin_unlock(&parent->d_lock);
-			inode_unlock(parent->d_inode);
-			parent = child;
-			goto down;
-		}
-
-		spin_unlock(&parent->d_lock);
-
-		if (!__tracefs_remove(child, parent))
-			simple_release_fs(&tracefs_mount, &tracefs_mount_count);
-
-		/*
-		 * The parent->d_lock protects agaist child from unlinking
-		 * from d_subdirs. When releasing the parent->d_lock we can
-		 * no longer trust that the next pointer is valid.
-		 * Restart the loop. We'll skip this one with the
-		 * simple_positive() check.
-		 */
-		goto loop;
-	}
-	spin_unlock(&parent->d_lock);
-
-	inode_unlock(parent->d_inode);
-	child = parent;
-	parent = parent->d_parent;
-	inode_lock(parent->d_inode);
-
-	if (child != dentry)
-		/* go up */
-		goto loop;
-
-	if (!__tracefs_remove(child, parent))
-		simple_release_fs(&tracefs_mount, &tracefs_mount_count);
-	inode_unlock(parent->d_inode);
+	simple_pin_fs(&trace_fs_type, &tracefs_mount, &tracefs_mount_count);
+	simple_recursive_removal(dentry, remove_one);
+	simple_release_fs(&tracefs_mount, &tracefs_mount_count);
 }
 
 /**