diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 9ce7d2872b554..b03bb91af24fb 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -27,7 +27,7 @@ static DEFINE_RWLOCK(kernfs_rename_lock); /* kn->parent and ->name */ */ static DEFINE_SPINLOCK(kernfs_pr_cont_lock); static char kernfs_pr_cont_buf[PATH_MAX]; /* protected by pr_cont_lock */ -static DEFINE_RAW_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */ +static DEFINE_SPINLOCK(kernfs_idr_lock); /* root->ino_idr */ #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) @@ -529,6 +529,20 @@ void kernfs_get(struct kernfs_node *kn) } EXPORT_SYMBOL_GPL(kernfs_get); +static void kernfs_free_rcu(struct rcu_head *rcu) +{ + struct kernfs_node *kn = container_of(rcu, struct kernfs_node, rcu); + + kfree_const(kn->name); + + if (kn->iattr) { + simple_xattrs_free(&kn->iattr->xattrs, NULL); + kmem_cache_free(kernfs_iattrs_cache, kn->iattr); + } + + kmem_cache_free(kernfs_node_cache, kn); +} + /** * kernfs_put - put a reference count on a kernfs_node * @kn: the target kernfs_node @@ -539,7 +553,6 @@ void kernfs_put(struct kernfs_node *kn) { struct kernfs_node *parent; struct kernfs_root *root; - unsigned long flags; if (!kn || !atomic_dec_and_test(&kn->count)) return; @@ -558,16 +571,11 @@ void kernfs_put(struct kernfs_node *kn) if (kernfs_type(kn) == KERNFS_LINK) kernfs_put(kn->symlink.target_kn); - kfree_const(kn->name); - - if (kn->iattr) { - simple_xattrs_free(&kn->iattr->xattrs, NULL); - kmem_cache_free(kernfs_iattrs_cache, kn->iattr); - } - raw_spin_lock_irqsave(&kernfs_idr_lock, flags); + spin_lock(&kernfs_idr_lock); idr_remove(&root->ino_idr, (u32)kernfs_ino(kn)); - raw_spin_unlock_irqrestore(&kernfs_idr_lock, flags); - kmem_cache_free(kernfs_node_cache, kn); + spin_unlock(&kernfs_idr_lock); + + call_rcu(&kn->rcu, kernfs_free_rcu); kn = parent; if (kn) { @@ -576,7 +584,7 @@ void kernfs_put(struct kernfs_node *kn) } else { /* just released the root kn, free @root too */ idr_destroy(&root->ino_idr); - kfree(root); + kfree_rcu(root, rcu); } } EXPORT_SYMBOL_GPL(kernfs_put); @@ -608,7 +616,6 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, struct kernfs_node *kn; u32 id_highbits; int ret; - unsigned long irqflags; name = kstrdup_const(name, GFP_KERNEL); if (!name) @@ -619,13 +626,13 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, goto err_out1; idr_preload(GFP_KERNEL); - raw_spin_lock_irqsave(&kernfs_idr_lock, irqflags); + spin_lock(&kernfs_idr_lock); ret = idr_alloc_cyclic(&root->ino_idr, kn, 1, 0, GFP_ATOMIC); if (ret >= 0 && ret < root->last_id_lowbits) root->id_highbits++; id_highbits = root->id_highbits; root->last_id_lowbits = ret; - raw_spin_unlock_irqrestore(&kernfs_idr_lock, irqflags); + spin_unlock(&kernfs_idr_lock); idr_preload_end(); if (ret < 0) goto err_out2; @@ -661,9 +668,9 @@ static struct kernfs_node *__kernfs_new_node(struct kernfs_root *root, return kn; err_out3: - raw_spin_lock_irqsave(&kernfs_idr_lock, irqflags); + spin_lock(&kernfs_idr_lock); idr_remove(&root->ino_idr, (u32)kernfs_ino(kn)); - raw_spin_unlock_irqrestore(&kernfs_idr_lock, irqflags); + spin_unlock(&kernfs_idr_lock); err_out2: kmem_cache_free(kernfs_node_cache, kn); err_out1: @@ -704,9 +711,8 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, struct kernfs_node *kn; ino_t ino = kernfs_id_ino(id); u32 gen = kernfs_id_gen(id); - unsigned long flags; - raw_spin_lock_irqsave(&kernfs_idr_lock, flags); + rcu_read_lock(); kn = idr_find(&root->ino_idr, (u32)ino); if (!kn) @@ -730,10 +736,10 @@ struct kernfs_node *kernfs_find_and_get_node_by_id(struct kernfs_root *root, if (unlikely(!__kernfs_active(kn) || !atomic_inc_not_zero(&kn->count))) goto err_unlock; - raw_spin_unlock_irqrestore(&kernfs_idr_lock, flags); + rcu_read_unlock(); return kn; err_unlock: - raw_spin_unlock_irqrestore(&kernfs_idr_lock, flags); + rcu_read_unlock(); return NULL; } diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 237f2764b9412..b42ee6547cdc1 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -49,6 +49,8 @@ struct kernfs_root { struct rw_semaphore kernfs_rwsem; struct rw_semaphore kernfs_iattr_rwsem; struct rw_semaphore kernfs_supers_rwsem; + + struct rcu_head rcu; }; /* +1 to avoid triggering overflow warning when negating it */ diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 99aaa050ccb76..05dcbae7ecbf2 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -206,6 +206,9 @@ struct kernfs_node { const void *ns; /* namespace tag */ unsigned int hash; /* ns + name hash */ + unsigned short flags; + umode_t mode; + union { struct kernfs_elem_dir dir; struct kernfs_elem_symlink symlink; @@ -220,9 +223,9 @@ struct kernfs_node { */ u64 id; - unsigned short flags; - umode_t mode; struct kernfs_iattrs *iattr; + + struct rcu_head rcu; }; /*