In preparation for converting DAX devices for use as system-ram via the
kernel's 'kmem' facility, add libndctl helpers to manipulate the sysfs
interfaces to get the target_node of a DAX device, and to online,
offline, and query the state of hotplugged memory sections associated
with a given node.
This adds the following new interfaces:
daxctl_dev_get_target_node
daxctl_dev_online_node
daxctl_dev_offline_node
daxctl_dev_node_is_online
Cc: Pavel Tatashin <pasha.tatas...@soleen.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Vishal Verma <vishal.l.ve...@intel.com>
---
daxctl/lib/libdaxctl-private.h | 6 +
daxctl/lib/libdaxctl.c | 228 +++++++++++++++++++++++++++++++++
daxctl/lib/libdaxctl.sym | 4 +
daxctl/libdaxctl.h | 4 +
4 files changed, 242 insertions(+)
diff --git a/daxctl/lib/libdaxctl-private.h b/daxctl/lib/libdaxctl-private.h
index e64d0a7..ef443aa 100644
--- a/daxctl/lib/libdaxctl-private.h
+++ b/daxctl/lib/libdaxctl-private.h
@@ -33,6 +33,11 @@ static const char *dax_modules[] = {
[DAXCTL_DEV_MODE_RAM] = "kmem",
};
+enum node_state {
+ NODE_OFFLINE,
+ NODE_ONLINE,
+};
+
/**
* struct daxctl_region - container for dax_devices
*/
@@ -63,6 +68,7 @@ struct daxctl_dev {
struct kmod_module *module;
struct kmod_list *kmod_list;
struct daxctl_region *region;
+ int target_node;
};
static inline int check_kmod(struct kmod_ctx *kmod_ctx)
diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c
index d50b321..aab2364 100644
--- a/daxctl/lib/libdaxctl.c
+++ b/daxctl/lib/libdaxctl.c
@@ -28,6 +28,7 @@
#include "libdaxctl-private.h"
static const char *attrs = "dax_region";
+static const char *node_base = "/sys/devices/system/node";
static void free_region(struct daxctl_region *region, struct list_head *head);
@@ -397,6 +398,12 @@ static void *add_dax_dev(void *parent, int id, const char
*daxdev_base)
} else
dbg(ctx, "%s: modalias attribute missing\n", devname);
+ sprintf(path, "%s/target_node", daxdev_base);
+ if (sysfs_read_attr(ctx, path, buf) == 0)
+ dev->target_node = strtol(buf, NULL, 0);
+ else
+ dev->target_node = -1;
+
daxctl_dev_foreach(region, dev_dup)
if (dev_dup->id == dev->id) {
free_dev(dev, NULL);
@@ -897,3 +904,224 @@ DAXCTL_EXPORT unsigned long long
daxctl_dev_get_size(struct daxctl_dev *dev)
{
return dev->size;
}
+
+DAXCTL_EXPORT int daxctl_dev_get_target_node(struct daxctl_dev *dev)
+{
+ return dev->target_node;
+}
+
+static int online_one_memblock(struct daxctl_dev *dev, char *path)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ const char *mode = "online_movable";
+ char buf[SYSFS_ATTR_SIZE];
+ int rc;
+
+ rc = sysfs_read_attr(ctx, path, buf);
+ if (rc) {
+ err(ctx, "%s: Failed to read %s: %s\n",
+ devname, path, strerror(-rc));
+ return rc;
+ }
+
+ /*
+ * if already online, possibly due to kernel config or a udev rule,
+ * there is nothing to do and we can skip over the memblock
+ */
+ if (strncmp(buf, "online", 6) == 0)
+ return 0;
+
+ rc = sysfs_write_attr_quiet(ctx, path, mode);
+ if (rc)
+ err(ctx, "%s: Failed to online %s: %s\n",
+ devname, path, strerror(-rc));
+ return rc;
+}
+
+static int offline_one_memblock(struct daxctl_dev *dev, char *path)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ const char *mode = "offline";
+ char buf[SYSFS_ATTR_SIZE];
+ int rc;
+
+ rc = sysfs_read_attr(ctx, path, buf);
+ if (rc) {
+ err(ctx, "%s: Failed to read %s: %s\n",
+ devname, path, strerror(-rc));
+ return rc;
+ }
+
+ /* if already offline, there is nothing to do */
+ if (strncmp(buf, "offline", 6) == 0)
+ return 0;
+
+ rc = sysfs_write_attr_quiet(ctx, path, mode);
+ if (rc)
+ err(ctx, "%s: Failed to offline %s: %s\n",
+ devname, path, strerror(-rc));
+ return rc;
+}
+
+static int daxctl_dev_node_set_state(struct daxctl_dev *dev,
+ enum node_state state)
+{
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ int target_node, rc, changed = 0;
+ struct dirent *de;
+ char *node_path;
+ DIR *node_dir;
+
+ target_node = daxctl_dev_get_target_node(dev);
+ if (target_node < 0) {
+ err(ctx, "%s: Unable to get target node\n",
+ daxctl_dev_get_devname(dev));
+ return -ENXIO;
+ }
+
+ rc = asprintf(&node_path, "%s/node%d", node_base, target_node);
+ if (rc < 0)
+ return -ENOMEM;
+
+ node_dir = opendir(node_path);
+ if (!node_dir) {
+ rc = -errno;
+ goto out_path;
+ }
+
+ errno = 0;
+ while ((de = readdir(node_dir)) != NULL) {
+ char *mem_path;
+
+ if (strcmp(de->d_name, ".") == 0 ||
+ strcmp(de->d_name, "..") == 0)
+ continue;
+ if (strncmp(de->d_name, "memory", 6) == 0) {
+ rc = asprintf(&mem_path, "%s/%s/state",
+ node_path, de->d_name);
+ if (rc < 0) {
+ rc = -ENOMEM;
+ goto out_dir;
+ }
+ if (state == NODE_ONLINE)
+ rc = online_one_memblock(dev, mem_path);
+ else if (state == NODE_OFFLINE)
+ rc = offline_one_memblock(dev, mem_path);
+ else
+ rc = -EINVAL;
+ free(mem_path);
+ if (rc)
+ goto out_dir;
+ changed++;
+ }
+ errno = 0;
+ }
+ if (errno) {
+ rc = -errno;
+ goto out_dir;
+ }
+ rc = changed;
+
+out_dir:
+ closedir(node_dir);
+out_path:
+ free(node_path);
+ return rc;
+}
+
+DAXCTL_EXPORT int daxctl_dev_online_node(struct daxctl_dev *dev)
+{
+ return daxctl_dev_node_set_state(dev, NODE_ONLINE);
+}
+
+DAXCTL_EXPORT int daxctl_dev_offline_node(struct daxctl_dev *dev)
+{
+ return daxctl_dev_node_set_state(dev, NODE_OFFLINE);
+}
+
+static int memblock_is_online(struct daxctl_dev *dev, char *path)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ char buf[SYSFS_ATTR_SIZE];
+ int rc;
+
+ rc = sysfs_read_attr(ctx, path, buf);
+ if (rc) {
+ err(ctx, "%s: Failed to read %s: %s\n",
+ devname, path, strerror(-rc));
+ return rc;
+ }
+
+ if (strncmp(buf, "online", 6) == 0)
+ return 1;
+
+ return 0;
+}
+
+DAXCTL_EXPORT int daxctl_dev_node_is_online(struct daxctl_dev *dev)
+{
+ const char *devname = daxctl_dev_get_devname(dev);
+ struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev);
+ int target_node, rc, num_online = 0;
+ struct dirent *de;
+ char *node_path;
+ DIR *node_dir;
+
+ target_node = daxctl_dev_get_target_node(dev);
+ if (target_node < 0) {
+ err(ctx, "%s: Unable to get target node\n", devname);
+ return -ENXIO;
+ }
+
+ rc = asprintf(&node_path, "%s/node%d", node_base, target_node);
+ if (rc < 0)
+ return -ENOMEM;
+
+ node_dir = opendir(node_path);
+ if (!node_dir) {
+ rc = -errno;
+ goto out_path;
+ }
+
+ errno = 0;
+ while ((de = readdir(node_dir)) != NULL) {
+ char *mem_path;
+
+ if (strcmp(de->d_name, ".") == 0 ||
+ strcmp(de->d_name, "..") == 0)
+ continue;
+ if (strncmp(de->d_name, "memory", 6) == 0) {
+ rc = asprintf(&mem_path, "%s/%s/state",
+ node_path, de->d_name);
+ if (rc < 0) {
+ rc = -ENOMEM;
+ goto out_dir;
+ }
+ rc = memblock_is_online(dev, mem_path);
+ if (rc < 0) {
+ err(ctx, "%s: Unable to determine state: %s\n",
+ devname, mem_path);
+ goto out_dir;
+ }
+ if (rc > 0)
+ num_online++;
+ free(mem_path);
+ }
+ errno = 0;
+ }
+ if (errno) {
+ rc = -errno;
+ goto out_dir;
+ }
+ rc = num_online;
+
+out_dir:
+ closedir(node_dir);
+out_path:
+ free(node_path);
+ return rc;
+
+}
diff --git a/daxctl/lib/libdaxctl.sym b/daxctl/lib/libdaxctl.sym
index 19904a2..cc47ed6 100644
--- a/daxctl/lib/libdaxctl.sym
+++ b/daxctl/lib/libdaxctl.sym
@@ -54,8 +54,12 @@ global:
LIBDAXCTL_6 {
global:
daxctl_dev_get_ctx;
+ daxctl_dev_get_target_node;
daxctl_dev_is_enabled;
daxctl_dev_disable;
daxctl_dev_enable_devdax;
daxctl_dev_enable_ram;
+ daxctl_dev_online_node;
+ daxctl_dev_offline_node;
+ daxctl_dev_node_is_online;
} LIBDAXCTL_5;
diff --git a/daxctl/libdaxctl.h b/daxctl/libdaxctl.h
index b80488e..db0d4ea 100644
--- a/daxctl/libdaxctl.h
+++ b/daxctl/libdaxctl.h
@@ -68,10 +68,14 @@ int daxctl_dev_get_major(struct daxctl_dev *dev);
int daxctl_dev_get_minor(struct daxctl_dev *dev);
unsigned long long daxctl_dev_get_size(struct daxctl_dev *dev);
struct daxctl_ctx *daxctl_dev_get_ctx(struct daxctl_dev *dev);
+int daxctl_dev_get_target_node(struct daxctl_dev *dev);
int daxctl_dev_is_enabled(struct daxctl_dev *dev);
int daxctl_dev_disable(struct daxctl_dev *dev);
int daxctl_dev_enable_devdax(struct daxctl_dev *dev);
int daxctl_dev_enable_ram(struct daxctl_dev *dev);
+int daxctl_dev_online_node(struct daxctl_dev *dev);
+int daxctl_dev_offline_node(struct daxctl_dev *dev);
+int daxctl_dev_node_is_online(struct daxctl_dev *dev);
#define daxctl_dev_foreach(region, dev) \
for (dev = daxctl_dev_get_first(region); \
--
2.20.1
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