vmstat_text is only available when PROC_FS or SYSFS is enabled. This

causes build errors in drivers/base/node.c when they are both disabled:

drivers/built-in.o: In function `node_read_vmstat':
node.c:(.text+0x10e28f): undefined reference to `vmstat_text'

Rather than litter drivers/base/node.c with #ifdef/#endif around the
affected lines of code, add macros for optional sysdev attributes so that
those lines of code will be ignored, without using #ifdef/#endif in the .c
file(s).  I.e., the ifdeffery is done only in a header file with
sysdev_create_file_optional() and sysdev_remove_file_optional().

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 793f796c4da3e1cd20143e1266d41246f2289b73..9e58e71911b3b7170e95200bc8d6d2bc9f6628ea 100644 (file)
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -176,6 +176,7 @@ static ssize_t node_read_numastat(struct sys_device * dev,
 }
 static SYSDEV_ATTR(numastat, S_IRUGO, node_read_numastat, NULL);
 
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS)
 static ssize_t node_read_vmstat(struct sys_device *dev,
                                struct sysdev_attribute *attr, char *buf)
 {
@@ -190,6 +191,7 @@ static ssize_t node_read_vmstat(struct sys_device *dev,
        return n;
 }
 static SYSDEV_ATTR(vmstat, S_IRUGO, node_read_vmstat, NULL);
+#endif
 
 static ssize_t node_read_distance(struct sys_device * dev,
                        struct sysdev_attribute *attr, char * buf)
@@ -274,7 +276,7 @@ int register_node(struct node *node, int num, struct node *parent)
                sysdev_create_file(&node->sysdev, &attr_meminfo);
                sysdev_create_file(&node->sysdev, &attr_numastat);
                sysdev_create_file(&node->sysdev, &attr_distance);
-               sysdev_create_file(&node->sysdev, &attr_vmstat);
+               sysdev_create_file_optional(&node->sysdev, &attr_vmstat);
 
                scan_unevictable_register_node(node);
 
@@ -299,7 +301,7 @@ void unregister_node(struct node *node)
        sysdev_remove_file(&node->sysdev, &attr_meminfo);
        sysdev_remove_file(&node->sysdev, &attr_numastat);
        sysdev_remove_file(&node->sysdev, &attr_distance);
-       sysdev_remove_file(&node->sysdev, &attr_vmstat);
+       sysdev_remove_file_optional(&node->sysdev, &attr_vmstat);
 
        scan_unevictable_unregister_node(node);
        hugetlb_unregister_node(node);          /* no-op, if memoryless node */

diff --git a/include/linux/sysdev.h b/include/linux/sysdev.h
index 20f63d3e6144654f0124170827eab474a1b41faa..6692a8e50eeaa3f7bf1205b6f03fb77af0884801 100644 (file)
--- a/include/linux/sysdev.h
+++ b/include/linux/sysdev.h
@@ -114,6 +114,20 @@ struct sysdev_attribute {
 extern int sysdev_create_file(struct sys_device *, struct sysdev_attribute *);
 extern void sysdev_remove_file(struct sys_device *, struct sysdev_attribute *);
 
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS)
+#define sysdev_create_file_optional(sysdev, sysdevattr)        \
+       return sysdev_create_file(sysdev, sysdevattr);
+
+#define sysdev_remove_file_optional(sysdev, sysdevattr)        \
+               sysdev_remove_file(sysdev, sysdevattr);
+#else
+#define sysdev_create_file_optional(sysdev, sysdevattr)        \
+               (0)
+
+#define sysdev_remove_file_optional(sysdev, sysdevattr)        \
+               do {} while (0)
+#endif
+
 /* Create/remove NULL terminated attribute list */
 static inline int
 sysdev_create_files(struct sys_device *d, struct sysdev_attribute **a)

diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 65efb92da996cecfcd1c3648e7ee4a450fe8dd01..b3b17ac0ad65c7e46522847347fd58f55cbd2060 100644 (file)
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -258,6 +258,8 @@ static inline void refresh_zone_stat_thresholds(void) { }
 
 #endif         /* CONFIG_SMP */
 
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS)
 extern const char * const vmstat_text[];
+#endif
 
 #endif /* _LINUX_VMSTAT_H */