#include "kernfs-internal.h"
-DEFINE_MUTEX(kernfs_mutex);
+DECLARE_RWSEM(kernfs_rwsem);
static DEFINE_SPINLOCK(kernfs_rename_lock); /* kn->parent and ->name */
static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by rename_lock */
static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */
static bool kernfs_active(struct kernfs_node *kn)
{
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held(&kernfs_rwsem);
return atomic_read(&kn->active) >= 0;
}
* @kn->parent->dir.children.
*
* Locking:
- * mutex_lock(kernfs_mutex)
+ * kernfs_rwsem held exclusive
*
* RETURNS:
* 0 on susccess -EEXIST on failure.
* removed, %false if @kn wasn't on the rbtree.
*
* Locking:
- * mutex_lock(kernfs_mutex)
+ * kernfs_rwsem held exclusive
*/
static bool kernfs_unlink_sibling(struct kernfs_node *kn)
{
* return after draining is complete.
*/
static void kernfs_drain(struct kernfs_node *kn)
- __releases(&kernfs_mutex) __acquires(&kernfs_mutex)
+ __releases(&kernfs_rwsem) __acquires(&kernfs_rwsem)
{
struct kernfs_root *root = kernfs_root(kn);
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
WARN_ON_ONCE(kernfs_active(kn));
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (kernfs_lockdep(kn)) {
rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
kernfs_drain_open_files(kn);
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
}
/**
bool has_ns;
int ret;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
ret = -EINVAL;
has_ns = kernfs_ns_enabled(parent);
ps_iattr->ia_mtime = ps_iattr->ia_ctime;
}
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
/*
* Activate the new node unless CREATE_DEACTIVATED is requested.
return 0;
out_unlock:
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return ret;
}
bool has_ns = kernfs_ns_enabled(parent);
unsigned int hash;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held(&kernfs_rwsem);
if (has_ns != (bool)ns) {
WARN(1, KERN_WARNING "kernfs: ns %s in '%s' for '%s'\n",
size_t len;
char *p, *name;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_read(&kernfs_rwsem);
/* grab kernfs_rename_lock to piggy back on kernfs_pr_cont_buf */
spin_lock_irq(&kernfs_rename_lock);
{
struct kernfs_node *kn;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
kn = kernfs_find_ns(parent, name, ns);
kernfs_get(kn);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return kn;
}
{
struct kernfs_node *kn;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
kn = kernfs_walk_ns(parent, path, ns);
kernfs_get(kn);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return kn;
}
/* If the kernfs parent node has changed discard and
* proceed to ->lookup.
*/
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
spin_lock(&dentry->d_lock);
parent = kernfs_dentry_node(dentry->d_parent);
if (parent) {
if (kernfs_dir_changed(parent, dentry)) {
spin_unlock(&dentry->d_lock);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 0;
}
}
spin_unlock(&dentry->d_lock);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
/* The kernfs parent node hasn't changed, leave the
* dentry negative and return success.
}
kn = kernfs_dentry_node(dentry);
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
/* The kernfs node has been deactivated */
if (!kernfs_active(kn))
kernfs_info(dentry->d_sb)->ns != kn->ns)
goto out_bad;
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 1;
out_bad:
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return 0;
}
struct inode *inode = NULL;
const void *ns = NULL;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
if (kernfs_ns_enabled(parent))
ns = kernfs_info(dir->i_sb)->ns;
kernfs_set_rev(parent, dentry);
/* instantiate and hash (possibly negative) dentry */
ret = d_splice_alias(inode, dentry);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
return ret;
}
{
struct rb_node *rbn;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
/* if first iteration, visit leftmost descendant which may be root */
if (!pos)
{
struct kernfs_node *pos;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
pos = NULL;
while ((pos = kernfs_next_descendant_post(pos, kn))) {
pos->flags |= KERNFS_ACTIVATED;
}
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
static void __kernfs_remove(struct kernfs_node *kn)
{
struct kernfs_node *pos;
- lockdep_assert_held(&kernfs_mutex);
+ lockdep_assert_held_write(&kernfs_rwsem);
/*
* Short-circuit if non-root @kn has already finished removal.
pos = kernfs_leftmost_descendant(kn);
/*
- * kernfs_drain() drops kernfs_mutex temporarily and @pos's
+ * kernfs_drain() drops kernfs_rwsem temporarily and @pos's
* base ref could have been put by someone else by the time
* the function returns. Make sure it doesn't go away
* underneath us.
*/
void kernfs_remove(struct kernfs_node *kn)
{
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
__kernfs_remove(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
}
/**
{
bool ret;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kernfs_break_active_protection(kn);
/*
* SUICIDAL is used to arbitrate among competing invocations. Only
* the first one will actually perform removal. When the removal
* is complete, SUICIDED is set and the active ref is restored
- * while holding kernfs_mutex. The ones which lost arbitration
- * waits for SUICDED && drained which can happen only after the
- * enclosing kernfs operation which executed the winning instance
- * of kernfs_remove_self() finished.
+ * while kernfs_rwsem for held exclusive. The ones which lost
+ * arbitration waits for SUICIDED && drained which can happen only
+ * after the enclosing kernfs operation which executed the winning
+ * instance of kernfs_remove_self() finished.
*/
if (!(kn->flags & KERNFS_SUICIDAL)) {
kn->flags |= KERNFS_SUICIDAL;
atomic_read(&kn->active) == KN_DEACTIVATED_BIAS)
break;
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
schedule();
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
}
finish_wait(waitq, &wait);
WARN_ON_ONCE(!RB_EMPTY_NODE(&kn->rb));
}
/*
- * This must be done while holding kernfs_mutex; otherwise, waiting
- * for SUICIDED && deactivated could finish prematurely.
+ * This must be done while kernfs_rwsem held exclusive; otherwise,
+ * waiting for SUICIDED && deactivated could finish prematurely.
*/
kernfs_unbreak_active_protection(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return ret;
}
return -ENOENT;
}
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
kn = kernfs_find_ns(parent, name, ns);
if (kn)
__kernfs_remove(kn);
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
if (kn)
return 0;
if (!kn->parent)
return -EINVAL;
- mutex_lock(&kernfs_mutex);
+ down_write(&kernfs_rwsem);
error = -ENOENT;
if (!kernfs_active(kn) || !kernfs_active(new_parent) ||
error = 0;
out:
- mutex_unlock(&kernfs_mutex);
+ up_write(&kernfs_rwsem);
return error;
}
if (!dir_emit_dots(file, ctx))
return 0;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
if (kernfs_ns_enabled(parent))
ns = kernfs_info(dentry->d_sb)->ns;
file->private_data = pos;
kernfs_get(pos);
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
if (!dir_emit(ctx, name, len, ino, type))
return 0;
- mutex_lock(&kernfs_mutex);
+ down_read(&kernfs_rwsem);
}
- mutex_unlock(&kernfs_mutex);
+ up_read(&kernfs_rwsem);
file->private_data = NULL;
ctx->pos = INT_MAX;
return 0;
projects / linux.git / commitdiff