7 files changed, 69 insertions, 47 deletions

diff --git a/arch/avr32/kernel/ocd.c b/arch/avr32/kernel/ocd.c
index c4f023294d75..1b0245d4e0ca 100644
--- a/arch/avr32/kernel/ocd.c
+++ b/arch/avr32/kernel/ocd.c
@@ -90,25 +90,29 @@ static struct dentry *ocd_debugfs_DC;
 static struct dentry *ocd_debugfs_DS;
 static struct dentry *ocd_debugfs_count;
 
-static u64 ocd_DC_get(void *data)
+static int ocd_DC_get(void *data, u64 *val)
 {
-        return ocd_read(DC);
+        *val = ocd_read(DC);
+        return 0;
 }
-static void ocd_DC_set(void *data, u64 val)
+static int ocd_DC_set(void *data, u64 val)
 {
         ocd_write(DC, val);
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_DC, ocd_DC_get, ocd_DC_set, "0x%08llx\n");
 
-static u64 ocd_DS_get(void *data)
+static int ocd_DS_get(void *data, u64 *val)
 {
-        return ocd_read(DS);
+        *val = ocd_read(DS);
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_DS, ocd_DS_get, NULL, "0x%08llx\n");
 
-static u64 ocd_count_get(void *data)
+static int ocd_count_get(void *data, u64 *val)
 {
-        return ocd_count;
+        *val = ocd_count;
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_count, ocd_count_get, NULL, "%lld\n");
 
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 1018acd1746b..9326714717ca 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -460,7 +460,7 @@ static int spufs_cntl_open(struct inode *inode, struct file *file)
         if (!i->i_openers++)
                 ctx->cntl = inode->i_mapping;
         mutex_unlock(&ctx->mapping_lock);
-        return spufs_attr_open(inode, file, spufs_cntl_get,
+        return simple_attr_open(inode, file, spufs_cntl_get,
                                         spufs_cntl_set, "0x%08lx");
 }
 
@@ -470,7 +470,7 @@ spufs_cntl_release(struct inode *inode, struct file *file)
         struct spufs_inode_info *i = SPUFS_I(inode);
         struct spu_context *ctx = i->i_ctx;
 
-        spufs_attr_release(inode, file);
+        simple_attr_close(inode, file);
 
         mutex_lock(&ctx->mapping_lock);
         if (!--i->i_openers)
@@ -482,8 +482,8 @@ spufs_cntl_release(struct inode *inode, struct file *file)
 static const struct file_operations spufs_cntl_fops = {
         .open = spufs_cntl_open,
         .release = spufs_cntl_release,
-        .read = spufs_attr_read,
-        .write = spufs_attr_write,
+        .read = simple_attr_read,
+        .write = simple_attr_write,
         .mmap = spufs_cntl_mmap,
 };
 
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index fa6b7f7ff914..fddffe4851f5 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -56,13 +56,15 @@ const struct inode_operations debugfs_link_operations = {
         .follow_link    = debugfs_follow_link,
 };
 
-static void debugfs_u8_set(void *data, u64 val)
+static int debugfs_u8_set(void *data, u64 val)
 {
         *(u8 *)data = val;
+        return 0;
 }
-static u64 debugfs_u8_get(void *data)
+static int debugfs_u8_get(void *data, u64 *val)
 {
-        return *(u8 *)data;
+        *val = *(u8 *)data;
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
 
@@ -97,13 +99,15 @@ struct dentry *debugfs_create_u8(const char *name, mode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u8);
 
-static void debugfs_u16_set(void *data, u64 val)
+static int debugfs_u16_set(void *data, u64 val)
 {
         *(u16 *)data = val;
+        return 0;
 }
-static u64 debugfs_u16_get(void *data)
+static int debugfs_u16_get(void *data, u64 *val)
 {
-        return *(u16 *)data;
+        *val = *(u16 *)data;
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
 
@@ -138,13 +142,15 @@ struct dentry *debugfs_create_u16(const char *name, mode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u16);
 
-static void debugfs_u32_set(void *data, u64 val)
+static int debugfs_u32_set(void *data, u64 val)
 {
         *(u32 *)data = val;
+        return 0;
 }
-static u64 debugfs_u32_get(void *data)
+static int debugfs_u32_get(void *data, u64 *val)
 {
-        return *(u32 *)data;
+        *val = *(u32 *)data;
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
 
@@ -179,14 +185,16 @@ struct dentry *debugfs_create_u32(const char *name, mode_t mode,
 }
 EXPORT_SYMBOL_GPL(debugfs_create_u32);
 
-static void debugfs_u64_set(void *data, u64 val)
+static int debugfs_u64_set(void *data, u64 val)
 {
         *(u64 *)data = val;
+        return 0;
 }
 
-static u64 debugfs_u64_get(void *data)
+static int debugfs_u64_get(void *data, u64 *val)
 {
-        return *(u64 *)data;
+        *val = *(u64 *)data;
+        return 0;
 }
 DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
 
diff --git a/fs/libfs.c b/fs/libfs.c
index 5523bde96387..2319415ddb5e 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -583,8 +583,8 @@ int simple_transaction_release(struct inode *inode, struct file *file)
 /* Simple attribute files */
 
 struct simple_attr {
-        u64 (*get)(void *);
-        void (*set)(void *, u64);
+        int (*get)(void *, u64 *);
+        int (*set)(void *, u64);
         char get_buf[24];       /* enough to store a u64 and "\n\0" */
         char set_buf[24];
         void *data;
@@ -595,7 +595,7 @@ struct simple_attr {
 /* simple_attr_open is called by an actual attribute open file operation
  * to set the attribute specific access operations. */
 int simple_attr_open(struct inode *inode, struct file *file,
-                     u64 (*get)(void *), void (*set)(void *, u64),
+                     int (*get)(void *, u64 *), int (*set)(void *, u64),
                      const char *fmt)
 {
         struct simple_attr *attr;
@@ -635,14 +635,20 @@ ssize_t simple_attr_read(struct file *file, char __user *buf,
                 return -EACCES;
 
         mutex_lock(&attr->mutex);
-        if (*ppos) /* continued read */
+        if (*ppos) {            /* continued read */
                 size = strlen(attr->get_buf);
-        else      /* first read */
+        } else {                /* first read */
+                u64 val;
+                ret = attr->get(attr->data, &val);
+                if (ret)
+                        goto out;
+
                 size = scnprintf(attr->get_buf, sizeof(attr->get_buf),
-                                 attr->fmt,
-                                 (unsigned long long)attr->get(attr->data));
+                                 attr->fmt, (unsigned long long)val);
+        }
 
         ret = simple_read_from_buffer(buf, len, ppos, attr->get_buf, size);
+out:
         mutex_unlock(&attr->mutex);
         return ret;
 }
@@ -657,7 +663,6 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
         ssize_t ret;
 
         attr = file->private_data;
-
         if (!attr->set)
                 return -EACCES;
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 36b7abefacbe..ebe996ac2589 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2068,7 +2068,7 @@ __simple_attr_check_format(const char *fmt, ...)
 }
 
 int simple_attr_open(struct inode *inode, struct file *file,
-                     u64 (*get)(void *), void (*set)(void *, u64),
+                     int (*get)(void *, u64 *), int (*set)(void *, u64),
                      const char *fmt);
 int simple_attr_close(struct inode *inode, struct file *file);
 ssize_t simple_attr_read(struct file *file, char __user *buf,
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 23985a278bbb..a50a311554cc 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -134,23 +134,26 @@ bool should_fail(struct fault_attr *attr, ssize_t size)
 
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
 
-static void debugfs_ul_set(void *data, u64 val)
+static int debugfs_ul_set(void *data, u64 val)
 {
         *(unsigned long *)data = val;
+        return 0;
 }
 
 #ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
-static void debugfs_ul_set_MAX_STACK_TRACE_DEPTH(void *data, u64 val)
+static int debugfs_ul_set_MAX_STACK_TRACE_DEPTH(void *data, u64 val)
 {
         *(unsigned long *)data =
                 val < MAX_STACK_TRACE_DEPTH ?
                 val : MAX_STACK_TRACE_DEPTH;
+        return 0;
 }
 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
 
-static u64 debugfs_ul_get(void *data)
+static int debugfs_ul_get(void *data, u64 *val)
 {
-        return *(unsigned long *)data;
+        *val = *(unsigned long *)data;
+        return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");
@@ -174,14 +177,16 @@ static struct dentry *debugfs_create_ul_MAX_STACK_TRACE_DEPTH(
 }
 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
 
-static void debugfs_atomic_t_set(void *data, u64 val)
+static int debugfs_atomic_t_set(void *data, u64 val)
 {
         atomic_set((atomic_t *)data, val);
+        return 0;
 }
 
-static u64 debugfs_atomic_t_get(void *data)
+static int debugfs_atomic_t_get(void *data, u64 *val)
 {
-        return atomic_read((atomic_t *)data);
+        *val = atomic_read((atomic_t *)data);
+        return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3c4fe26096fc..32fbf8006969 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1186,38 +1186,38 @@ static struct notifier_block kvm_cpu_notifier = {
         .priority = 20, /* must be > scheduler priority */
 };
 
-static u64 vm_stat_get(void *_offset)
+static int vm_stat_get(void *_offset, u64 *val)
 {
         unsigned offset = (long)_offset;
-        u64 total = 0;
         struct kvm *kvm;
 
+        *val = 0;
         spin_lock(&kvm_lock);
         list_for_each_entry(kvm, &vm_list, vm_list)
-                total += *(u32 *)((void *)kvm + offset);
+                *val += *(u32 *)((void *)kvm + offset);
         spin_unlock(&kvm_lock);
-        return total;
+        return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, NULL, "%llu\n");
 
-static u64 vcpu_stat_get(void *_offset)
+static int vcpu_stat_get(void *_offset, u64 *val)
 {
         unsigned offset = (long)_offset;
-        u64 total = 0;
         struct kvm *kvm;
         struct kvm_vcpu *vcpu;
         int i;
 
+        *val = 0;
         spin_lock(&kvm_lock);
         list_for_each_entry(kvm, &vm_list, vm_list)
                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                         vcpu = kvm->vcpus[i];
                         if (vcpu)
-                                total += *(u32 *)((void *)vcpu + offset);
+                                *val += *(u32 *)((void *)vcpu + offset);
                 }
         spin_unlock(&kvm_lock);
-        return total;
+        return 0;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, NULL, "%llu\n");