kvm: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

This cleans up the error handling a lot, as this code will never get
hit.

Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim KrÄmář" <rkrcmar@redhat.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.cs.columbia.edu
Cc: kvm@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 4d07fca5121c56270aafd6f820009561d399d628..67d7de1470ccb4253493ac5d4fcbc781747bc7d0 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3950,8 +3950,7 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
         */
        snprintf(buf, sizeof(buf), "vm%d", current->pid);
        kvm->arch.debugfs_dir = debugfs_create_dir(buf, kvm_debugfs_dir);
-       if (!IS_ERR_OR_NULL(kvm->arch.debugfs_dir))
-               kvmppc_mmu_debugfs_init(kvm);
+       kvmppc_mmu_debugfs_init(kvm);
 
        return 0;
 }

diff --git a/virt/kvm/arm/vgic/vgic-debug.c b/virt/kvm/arm/vgic/vgic-debug.c
index 4ffc0b5e610560c752c99de33d6f5857e7344773..c589d4c2b478b2df7ada6cee1837340c762a41b5 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-debug.c
+++ b/virt/kvm/arm/vgic/vgic-debug.c
@@ -264,21 +264,12 @@ static const struct file_operations vgic_debug_fops = {
        .release = seq_release
 };
 
-int vgic_debug_init(struct kvm *kvm)
+void vgic_debug_init(struct kvm *kvm)
 {
-       if (!kvm->debugfs_dentry)
-               return -ENOENT;
-
-       if (!debugfs_create_file("vgic-state", 0444,
-                                kvm->debugfs_dentry,
-                                kvm,
-                                &vgic_debug_fops))
-               return -ENOMEM;
-
-       return 0;
+       debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
+                           &vgic_debug_fops);
 }
 
-int vgic_debug_destroy(struct kvm *kvm)
+void vgic_debug_destroy(struct kvm *kvm)
 {
-       return 0;
 }

diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 6879cf48652a139b3f12641c35e7a184d2e7e02b..ead00b2072b260321c31330e20a8031b5ba362d8 100644 (file)
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -250,8 +250,8 @@ void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
 int vgic_lazy_init(struct kvm *kvm);
 int vgic_init(struct kvm *kvm);
 
-int vgic_debug_init(struct kvm *kvm);
-int vgic_debug_destroy(struct kvm *kvm);
+void vgic_debug_init(struct kvm *kvm);
+void vgic_debug_destroy(struct kvm *kvm);
 
 bool lock_all_vcpus(struct kvm *kvm);
 void unlock_all_vcpus(struct kvm *kvm);

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 8938c9e553df438603d90dea5f8d75a3e6ae2142..aa7da1d8ece2784a94dd15dcec6588b0e8a57466 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -590,10 +590,7 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
                return 0;
 
        snprintf(dir_name, sizeof(dir_name), "%d-%d", task_pid_nr(current), fd);
-       kvm->debugfs_dentry = debugfs_create_dir(dir_name,
-                                                kvm_debugfs_dir);
-       if (!kvm->debugfs_dentry)
-               return -ENOMEM;
+       kvm->debugfs_dentry = debugfs_create_dir(dir_name, kvm_debugfs_dir);
 
        kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries,
                                         sizeof(*kvm->debugfs_stat_data),
@@ -609,11 +606,8 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
                stat_data->kvm = kvm;
                stat_data->offset = p->offset;
                kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
-               if (!debugfs_create_file(p->name, 0644,
-                                        kvm->debugfs_dentry,
-                                        stat_data,
-                                        stat_fops_per_vm[p->kind]))
-                       return -ENOMEM;
+               debugfs_create_file(p->name, 0644, kvm->debugfs_dentry,
+                                   stat_data, stat_fops_per_vm[p->kind]);
        }
        return 0;
 }
@@ -3919,29 +3913,18 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
        kfree(env);
 }
 
-static int kvm_init_debug(void)
+static void kvm_init_debug(void)
 {
-       int r = -EEXIST;
        struct kvm_stats_debugfs_item *p;
 
        kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
-       if (kvm_debugfs_dir == NULL)
-               goto out;
 
        kvm_debugfs_num_entries = 0;
        for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
-               if (!debugfs_create_file(p->name, 0644, kvm_debugfs_dir,
-                                        (void *)(long)p->offset,
-                                        stat_fops[p->kind]))
-                       goto out_dir;
+               debugfs_create_file(p->name, 0644, kvm_debugfs_dir,
+                                   (void *)(long)p->offset,
+                                   stat_fops[p->kind]);
        }
-
-       return 0;
-
-out_dir:
-       debugfs_remove_recursive(kvm_debugfs_dir);
-out:
-       return r;
 }
 
 static int kvm_suspend(void)
@@ -4069,20 +4052,13 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
        kvm_preempt_ops.sched_in = kvm_sched_in;
        kvm_preempt_ops.sched_out = kvm_sched_out;
 
-       r = kvm_init_debug();
-       if (r) {
-               pr_err("kvm: create debugfs files failed\n");
-               goto out_undebugfs;
-       }
+       kvm_init_debug();
 
        r = kvm_vfio_ops_init();
        WARN_ON(r);
 
        return 0;
 
-out_undebugfs:
-       unregister_syscore_ops(&kvm_syscore_ops);
-       misc_deregister(&kvm_dev);
 out_unreg:
        kvm_async_pf_deinit();
 out_free: