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.

Also, when doing this, change kvm_arch_create_vcpu_debugfs() to return
void instead of an integer, as we should not care at all about if this
function actually does anything or not.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <x86@kernel.org>
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/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
index 9bd93e0d5f6385c53381627bc8a023ef8b7396fc..018aebce33ff407f764d17151c3d3647e8014263 100644 (file)
--- a/arch/x86/kvm/debugfs.c
+++ b/arch/x86/kvm/debugfs.c
@@ -43,37 +43,22 @@ static int vcpu_get_tsc_scaling_frac_bits(void *data, u64 *val)
 
 DEFINE_SIMPLE_ATTRIBUTE(vcpu_tsc_scaling_frac_fops, vcpu_get_tsc_scaling_frac_bits, NULL, "%llu\n");
 
-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
+void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 {
-       struct dentry *ret;
+       debugfs_create_file("tsc-offset", 0444, vcpu->debugfs_dentry, vcpu,
+                           &vcpu_tsc_offset_fops);
 
-       ret = debugfs_create_file("tsc-offset", 0444,
-                                                       vcpu->debugfs_dentry,
-                                                       vcpu, &vcpu_tsc_offset_fops);
-       if (!ret)
-               return -ENOMEM;
-
-       if (lapic_in_kernel(vcpu)) {
-               ret = debugfs_create_file("lapic_timer_advance_ns", 0444,
-                                                               vcpu->debugfs_dentry,
-                                                               vcpu, &vcpu_timer_advance_ns_fops);
-               if (!ret)
-                       return -ENOMEM;
-       }
+       if (lapic_in_kernel(vcpu))
+               debugfs_create_file("lapic_timer_advance_ns", 0444,
+                                   vcpu->debugfs_dentry, vcpu,
+                                   &vcpu_timer_advance_ns_fops);
 
        if (kvm_has_tsc_control) {
-               ret = debugfs_create_file("tsc-scaling-ratio", 0444,
-                                                       vcpu->debugfs_dentry,
-                                                       vcpu, &vcpu_tsc_scaling_fops);
-               if (!ret)
-                       return -ENOMEM;
-               ret = debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
-                                                       vcpu->debugfs_dentry,
-                                                       vcpu, &vcpu_tsc_scaling_frac_fops);
-               if (!ret)
-                       return -ENOMEM;
-
+               debugfs_create_file("tsc-scaling-ratio", 0444,
+                                   vcpu->debugfs_dentry, vcpu,
+                                   &vcpu_tsc_scaling_fops);
+               debugfs_create_file("tsc-scaling-ratio-frac-bits", 0444,
+                                   vcpu->debugfs_dentry, vcpu,
+                                   &vcpu_tsc_scaling_frac_fops);
        }
-
-       return 0;
 }

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8d34db3c8bc6886258cd49b411258100374f757f..fcb46b3374c60967993cf6123172c35a7cac4277 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -862,7 +862,7 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu);
 
 #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
-int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu);
+void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu);
 #endif
 
 int kvm_arch_hardware_enable(void);

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4afb1a234018bbb514ecb7f7d7a0f49f6eb8a5a7..4feceaa03fb1dcdb387c6297f66d43406e485b44 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2615,29 +2615,20 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu)
        return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC);
 }
 
-static int kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
+static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
 {
 #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS
        char dir_name[ITOA_MAX_LEN * 2];
-       int ret;
 
        if (!debugfs_initialized())
-               return 0;
+               return;
 
        snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id);
        vcpu->debugfs_dentry = debugfs_create_dir(dir_name,
-                                                               vcpu->kvm->debugfs_dentry);
-       if (!vcpu->debugfs_dentry)
-               return -ENOMEM;
+                                                 vcpu->kvm->debugfs_dentry);
 
-       ret = kvm_arch_create_vcpu_debugfs(vcpu);
-       if (ret < 0) {
-               debugfs_remove_recursive(vcpu->debugfs_dentry);
-               return ret;
-       }
+       kvm_arch_create_vcpu_debugfs(vcpu);
 #endif
-
-       return 0;
 }
 
 /*
@@ -2672,9 +2663,7 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
        if (r)
                goto vcpu_destroy;
 
-       r = kvm_create_vcpu_debugfs(vcpu);
-       if (r)
-               goto vcpu_destroy;
+       kvm_create_vcpu_debugfs(vcpu);
 
        mutex_lock(&kvm->lock);
        if (kvm_get_vcpu_by_id(kvm, id)) {