[PATCH v2 01/25] staging: lustre: libcfs: restore UMP handling

[James Simmons]

With the cleanup of the libcfs SMP handling all UMP handling
was removed. In the process now various NULL pointers and
empty fields are return in the UMP case which causes lustre
to crash hard. Restore the proper UMP handling so Lustre can
properly function.

Signed-off-by: James Simmons <uja.ornl@xxxxxxxxx>
Signed-off-by: Amir Shehata <amir.shehata@xxxxxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7734
Reviewed-on: http://review.whamcloud.com/18916
Reviewed-by: Olaf Weber <olaf@xxxxxxx>
Reviewed-by: Doug Oucharek <dougso@xxxxxx>
Signed-off-by: James Simmons <jsimmons@xxxxxxxxxxxxx>
---
Changelog:

v1) New patch to handle the disappearence of UMP support

 .../lustre/include/linux/libcfs/libcfs_cpu.h       | 87 ++++++++++++++++------
 drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c    |  4 -
 drivers/staging/lustre/lnet/libcfs/module.c        |  4 +
 3 files changed, 69 insertions(+), 26 deletions(-)

diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h b/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
index 61641c4..2ad12a6 100644
--- a/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
+++ b/drivers/staging/lustre/include/linux/libcfs/libcfs_cpu.h
@@ -74,6 +74,7 @@
 
 #include <linux/cpu.h>
 #include <linux/cpuset.h>
+#include <linux/slab.h>
 #include <linux/topology.h>
 
 /* any CPU partition */
@@ -89,10 +90,11 @@ struct cfs_cpu_partition {
 	/* spread rotor for NUMA allocator */
 	unsigned int			cpt_spread_rotor;
 };
-
+#endif /* CONFIG_SMP */
 
 /** descriptor for CPU partitions */
 struct cfs_cpt_table {
+#ifdef CONFIG_SMP
 	/* version, reserved for hotplug */
 	unsigned int			ctb_version;
 	/* spread rotor for NUMA allocator */
@@ -103,14 +105,26 @@ struct cfs_cpt_table {
 	struct cfs_cpu_partition	*ctb_parts;
 	/* shadow HW CPU to CPU partition ID */
 	int				*ctb_cpu2cpt;
-	/* all cpus in this partition table */
-	cpumask_var_t			ctb_cpumask;
 	/* all nodes in this partition table */
 	nodemask_t			*ctb_nodemask;
+#else
+	nodemask_t			ctb_nodemask;
+#endif /* CONFIG_SMP */
+	/* all cpus in this partition table */
+	cpumask_var_t			ctb_cpumask;
 };
 
 extern struct cfs_cpt_table	*cfs_cpt_tab;
 
+#ifdef CONFIG_SMP
+/**
+ * destroy a CPU partition table
+ */
+void cfs_cpt_table_free(struct cfs_cpt_table *cptab);
+/**
+ * create a cfs_cpt_table with \a ncpt number of partitions
+ */
+struct cfs_cpt_table *cfs_cpt_table_alloc(unsigned int ncpt);
 /**
  * return cpumask of CPU partition \a cpt
  */
@@ -208,20 +222,52 @@ void cfs_cpt_unset_nodemask(struct cfs_cpt_table *cptab,
 void cfs_cpu_fini(void);
 
 #else /* !CONFIG_SMP */
-struct cfs_cpt_table;
-#define cfs_cpt_tab ((struct cfs_cpt_table *)NULL)
 
-static inline cpumask_var_t *
-cfs_cpt_cpumask(struct cfs_cpt_table *cptab, int cpt)
+static inline void cfs_cpt_table_free(struct cfs_cpt_table *cptab)
 {
-	return NULL;
+	kfree(cptab);
 }
 
-static inline int
-cfs_cpt_table_print(struct cfs_cpt_table *cptab, char *buf, int len)
+static inline struct cfs_cpt_table *cfs_cpt_table_alloc(int ncpt)
 {
-	return 0;
+	struct cfs_cpt_table *cptab;
+
+	if (ncpt != 1)
+		return NULL;
+
+	cptab = kzalloc(sizeof(*cptab), GFP_NOFS);
+	if (!cptab)
+		return NULL;
+
+	if (!zalloc_cpumask_var(&cptab->ctb_cpumask, GFP_NOFS)) {
+		kfree(cptab);
+		return NULL;
+	}
+	cpumask_set_cpu(0, cptab->ctb_cpumask);
+	node_set(0, cptab->ctb_nodemask);
+
+	return cptab;
+}
+
+static inline int cfs_cpt_table_print(struct cfs_cpt_table *cptab,
+				      char *buf, int len)
+{
+	int rc;
+
+	rc = snprintf(buf, len, "0\t: 0\n");
+	len -= rc;
+	if (len <= 0)
+		return -EFBIG;
+
+	return rc;
 }
+
+static inline cpumask_var_t *
+cfs_cpt_cpumask(struct cfs_cpt_table *cptab, int cpt)
+{
+	return &cptab->ctb_cpumask;
+}
+
 static inline int
 cfs_cpt_number(struct cfs_cpt_table *cptab)
 {
@@ -243,7 +289,7 @@ void cfs_cpt_unset_nodemask(struct cfs_cpt_table *cptab,
 static inline nodemask_t *
 cfs_cpt_nodemask(struct cfs_cpt_table *cptab, int cpt)
 {
-	return NULL;
+	return &cptab->ctb_nodemask;
 }
 
 static inline int
@@ -328,24 +374,21 @@ void cfs_cpt_unset_nodemask(struct cfs_cpt_table *cptab,
 static inline int
 cfs_cpu_init(void)
 {
-	return 0;
+	cfs_cpt_tab = cfs_cpt_table_alloc(1);
+
+	return cfs_cpt_tab ? 0 : -1;
 }
 
 static inline void cfs_cpu_fini(void)
 {
+	if (cfs_cpt_tab) {
+		cfs_cpt_table_free(cfs_cpt_tab);
+		cfs_cpt_tab = NULL;
+	}
 }
 
 #endif /* CONFIG_SMP */
 
-/**
- * destroy a CPU partition table
- */
-void cfs_cpt_table_free(struct cfs_cpt_table *cptab);
-/**
- * create a cfs_cpt_table with \a ncpt number of partitions
- */
-struct cfs_cpt_table *cfs_cpt_table_alloc(unsigned int ncpt);
-
 /*
  * allocate per-cpu-partition data, returned value is an array of pointers,
  * variable can be indexed by CPU ID.
diff --git a/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c b/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
index 3d1cf45..803fc58 100644
--- a/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
+++ b/drivers/staging/lustre/lnet/libcfs/libcfs_cpu.c
@@ -41,10 +41,6 @@
 #include <linux/libcfs/libcfs_string.h>
 #include <linux/libcfs/libcfs.h>
 
-/** Global CPU partition table */
-struct cfs_cpt_table   *cfs_cpt_tab __read_mostly;
-EXPORT_SYMBOL(cfs_cpt_tab);
-
 /**
  * modparam for setting number of partitions
  *
diff --git a/drivers/staging/lustre/lnet/libcfs/module.c b/drivers/staging/lustre/lnet/libcfs/module.c
index 5dc7de9..b438d456 100644
--- a/drivers/staging/lustre/lnet/libcfs/module.c
+++ b/drivers/staging/lustre/lnet/libcfs/module.c
@@ -66,6 +66,10 @@ struct lnet_debugfs_symlink_def {
 
 static struct dentry *lnet_debugfs_root;
 
+/** Global CPU partition table */
+struct cfs_cpt_table  *cfs_cpt_tab __read_mostly;
+EXPORT_SYMBOL(cfs_cpt_tab);
+
 BLOCKING_NOTIFIER_HEAD(libcfs_ioctl_list);
 EXPORT_SYMBOL(libcfs_ioctl_list);
 
-- 
1.8.3.1