[Bionic][PATCH 01/18] kvm: no need to check return value of debugfs_create functions
Jose Ricardo Ziviani
joserz at linux.ibm.com
Wed Oct 31 15:09:14 UTC 2018
From: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
BugLink: https://bugs.launchpad.net/qemu-kvm/+bug/1800649
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 at ozlabs.org>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Christoffer Dall <christoffer.dall at arm.com>
Cc: Marc Zyngier <marc.zyngier at arm.com>
Cc: Paolo Bonzini <pbonzini at redhat.com>
Cc: "Radim KrÄmář" <rkrcmar at redhat.com>
Cc: Arvind Yadav <arvind.yadav.cs at gmail.com>
Cc: Eric Auger <eric.auger at redhat.com>
Cc: Andre Przywara <andre.przywara at arm.com>
Cc: kvm-ppc at vger.kernel.org
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: kvmarm at lists.cs.columbia.edu
Cc: kvm at vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
(cherry picked from commit 929f45e32499171ce3e5a15db972256eac513ad7)
Signed-off-by: Jose Ricardo Ziviani <joserz at linux.ibm.com>
---
arch/powerpc/kvm/book3s_hv.c | 3 +--
virt/kvm/arm/vgic/vgic-debug.c | 17 ++++-----------
virt/kvm/arm/vgic/vgic.h | 4 ++--
virt/kvm/kvm_main.c | 40 +++++++---------------------------
4 files changed, 15 insertions(+), 49 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index dc9eb6b495ce..9f4da904ebee 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -3954,8 +3954,7 @@ 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 4ffc0b5e6105..c589d4c2b478 100644
--- 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 3742fa670c9c..661155686c81 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -218,8 +218,8 @@ 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 234d03abcb75..a25ae49d3e1c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -577,10 +577,7 @@ 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),
@@ -596,11 +593,8 @@ 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)
@@ -4065,20 +4048,13 @@ 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:
--
2.17.2
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