Update Linux to v5.10.157
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.157.tar.xz
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I7b30d9e98d8c465d6b44de8e7433b4a40b3289ba
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 9aec80b..8b3c86a 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -19,7 +19,15 @@
DEFINE_MUTEX(kernfs_mutex);
static DEFINE_SPINLOCK(kernfs_rename_lock); /* kn->parent and ->name */
-static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by rename_lock */
+/*
+ * Don't use rename_lock to piggy back on pr_cont_buf. We don't want to
+ * call pr_cont() while holding rename_lock. Because sometimes pr_cont()
+ * will perform wakeups when releasing console_sem. Holding rename_lock
+ * will introduce deadlock if the scheduler reads the kernfs_name in the
+ * wakeup path.
+ */
+static DEFINE_SPINLOCK(kernfs_pr_cont_lock);
+static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by pr_cont_lock */
static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */
#define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb)
@@ -230,12 +238,12 @@
{
unsigned long flags;
- spin_lock_irqsave(&kernfs_rename_lock, flags);
+ spin_lock_irqsave(&kernfs_pr_cont_lock, flags);
- kernfs_name_locked(kn, kernfs_pr_cont_buf, sizeof(kernfs_pr_cont_buf));
+ kernfs_name(kn, kernfs_pr_cont_buf, sizeof(kernfs_pr_cont_buf));
pr_cont("%s", kernfs_pr_cont_buf);
- spin_unlock_irqrestore(&kernfs_rename_lock, flags);
+ spin_unlock_irqrestore(&kernfs_pr_cont_lock, flags);
}
/**
@@ -249,10 +257,10 @@
unsigned long flags;
int sz;
- spin_lock_irqsave(&kernfs_rename_lock, flags);
+ spin_lock_irqsave(&kernfs_pr_cont_lock, flags);
- sz = kernfs_path_from_node_locked(kn, NULL, kernfs_pr_cont_buf,
- sizeof(kernfs_pr_cont_buf));
+ sz = kernfs_path_from_node(kn, NULL, kernfs_pr_cont_buf,
+ sizeof(kernfs_pr_cont_buf));
if (sz < 0) {
pr_cont("(error)");
goto out;
@@ -266,7 +274,7 @@
pr_cont("%s", kernfs_pr_cont_buf);
out:
- spin_unlock_irqrestore(&kernfs_rename_lock, flags);
+ spin_unlock_irqrestore(&kernfs_pr_cont_lock, flags);
}
/**
@@ -864,13 +872,12 @@
lockdep_assert_held(&kernfs_mutex);
- /* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
- spin_lock_irq(&kernfs_rename_lock);
+ spin_lock_irq(&kernfs_pr_cont_lock);
len = strlcpy(kernfs_pr_cont_buf, path, sizeof(kernfs_pr_cont_buf));
if (len >= sizeof(kernfs_pr_cont_buf)) {
- spin_unlock_irq(&kernfs_rename_lock);
+ spin_unlock_irq(&kernfs_pr_cont_lock);
return NULL;
}
@@ -882,7 +889,7 @@
parent = kernfs_find_ns(parent, name, ns);
}
- spin_unlock_irq(&kernfs_rename_lock);
+ spin_unlock_irq(&kernfs_pr_cont_lock);
return parent;
}
@@ -1512,8 +1519,11 @@
mutex_lock(&kernfs_mutex);
kn = kernfs_find_ns(parent, name, ns);
- if (kn)
+ if (kn) {
+ kernfs_get(kn);
__kernfs_remove(kn);
+ kernfs_put(kn);
+ }
mutex_unlock(&kernfs_mutex);