From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 57797212BF9B9 for ; Wed, 17 Jul 2019 15:56:36 -0700 (PDT) From: Vishal Verma Subject: [ndctl PATCH v6 04/13] libdaxctl: add a 'daxctl_memory' object for memory based operations Date: Wed, 17 Jul 2019 16:53:51 -0600 Message-Id: <20190717225400.9494-5-vishal.l.verma@intel.com> In-Reply-To: <20190717225400.9494-1-vishal.l.verma@intel.com> References: <20190717225400.9494-1-vishal.l.verma@intel.com> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: linux-nvdimm@lists.01.org Cc: Dave Hansen , Pavel Tatashin List-ID: Introduce a new 'daxctl_memory' object, which will be used for operations related to managing dax devices in 'system-memory' modes. Add libdaxctl APIs 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 device. This adds the following new interfaces: daxctl_dev_get_target_node daxctl_dev_get_memory; daxctl_memory_get_dev; daxctl_memory_get_node_path; daxctl_memory_get_block_size; daxctl_memory_set_online daxctl_memory_set_offline daxctl_memory_is_online Cc: Pavel Tatashin Cc: Dave Hansen Cc: Dan Williams [for the memblock-already-online TOCTOU hole] Reported-by: Fan Du Tested-by: Fan Du Signed-off-by: Vishal Verma --- daxctl/lib/libdaxctl-private.h | 14 ++ daxctl/lib/libdaxctl.c | 352 +++++++++++++++++++++++++++++++++ daxctl/lib/libdaxctl.sym | 8 + daxctl/libdaxctl.h | 10 + 4 files changed, 384 insertions(+) diff --git a/daxctl/lib/libdaxctl-private.h b/daxctl/lib/libdaxctl-private.h index eb7c1ec..673be0f 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 memory_state { + MEM_OFFLINE, + MEM_ONLINE, +}; + /** * struct daxctl_region - container for dax_devices */ @@ -64,8 +69,17 @@ struct daxctl_dev { struct kmod_module *module; struct kmod_list *kmod_list; struct daxctl_region *region; + struct daxctl_memory *mem; + int target_node; }; +struct daxctl_memory { +struct daxctl_dev *dev; + char *node_path; + unsigned long block_size; +}; + + static inline int check_kmod(struct kmod_ctx *kmod_ctx) { return kmod_ctx ? 0 : -ENXIO; diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c index 5431063..4c1cbf3 100644 --- a/daxctl/lib/libdaxctl.c +++ b/daxctl/lib/libdaxctl.c @@ -200,6 +200,12 @@ DAXCTL_EXPORT void daxctl_region_get_uuid(struct daxctl_region *region, uuid_t u uuid_copy(uu, region->uuid); } +static void free_mem(struct daxctl_memory *mem) +{ + free(mem->node_path); + free(mem); +} + static void free_dev(struct daxctl_dev *dev, struct list_head *head) { if (head) @@ -207,6 +213,7 @@ static void free_dev(struct daxctl_dev *dev, struct list_head *head) kmod_module_unref_list(dev->kmod_list); free(dev->dev_buf); free(dev->dev_path); + free_mem(dev->mem); free(dev); } @@ -343,6 +350,44 @@ static struct kmod_list *to_module_list(struct daxctl_ctx *ctx, return list; } +static struct daxctl_memory *daxctl_dev_init_mem(struct daxctl_dev *dev) +{ + const char *size_path = "/sys/devices/system/memory/block_size_bytes"; + const char *node_base = "/sys/devices/system/node/node"; + const char *devname = daxctl_dev_get_devname(dev); + struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + struct daxctl_memory *mem; + char buf[SYSFS_ATTR_SIZE]; + int node_num; + + mem = calloc(1, sizeof(*mem)); + if (!mem) + return NULL; + + mem->dev = dev; + + /* + * Everything here is best-effort, we won't fail the device add + * for anything other than the ENOMEM case above. + */ + if (sysfs_read_attr(ctx, size_path, buf) == 0) { + mem->block_size = strtoul(buf, NULL, 16); + if (mem->block_size == 0 || mem->block_size == ULONG_MAX) { + err(ctx, "%s: Unable to determine memblock size: %s\n", + devname, strerror(errno)); + mem->block_size = 0; + } + } + + node_num = daxctl_dev_get_target_node(dev); + if (node_num >= 0) { + if (asprintf(&mem->node_path, "%s%d", node_base, node_num) < 0) + err(ctx, "%s: Unable to set node_path\n", devname); + } + + return mem; +} + static void *add_dax_dev(void *parent, int id, const char *daxdev_base) { const char *devname = devpath_to_devname(daxdev_base); @@ -398,6 +443,16 @@ static void *add_dax_dev(void *parent, int id, const char *daxdev_base) if (rc == 0) dev->kmod_list = to_module_list(ctx, buf); + 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; + + dev->mem = daxctl_dev_init_mem(dev); + if (!dev->mem) + goto err_read; + daxctl_dev_foreach(region, dev_dup) if (dev_dup->id == dev->id) { free_dev(dev, NULL); @@ -894,3 +949,300 @@ 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; +} + +DAXCTL_EXPORT struct daxctl_memory *daxctl_dev_get_memory(struct daxctl_dev *dev) +{ + return dev->mem; +} + +DAXCTL_EXPORT struct daxctl_dev *daxctl_memory_get_dev(struct daxctl_memory *mem) +{ + return mem->dev; +} + +DAXCTL_EXPORT const char *daxctl_memory_get_node_path(struct daxctl_memory *mem) +{ + return mem->node_path; +} + +DAXCTL_EXPORT unsigned long daxctl_memory_get_block_size(struct daxctl_memory *mem) +{ + return mem->block_size; +} + +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 1; + + rc = sysfs_write_attr_quiet(ctx, path, mode); + if (rc) { + /* + * While we performed an already-online check above, there + * is still a TOCTOU hole where someone (such as a udev rule) + * may have raced to online the memory. In such a case, + * the sysfs store will fail, however we can check for this + * by simply reading the state again. If it changed to the + * desired state, then we don't have to error out. + */ + if(sysfs_read_attr(ctx, path, buf) == 0) { + if (strncmp(buf, "online", 6) == 0) + return 1; + } + 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", 7) == 0) + return 1; + + rc = sysfs_write_attr_quiet(ctx, path, mode); + if (rc) { + /* Close the TOCTOU hole like in online_one_memblock() above */ + if(sysfs_read_attr(ctx, path, buf) == 0) { + if (strncmp(buf, "offline", 7) == 0) + return 1; + } + err(ctx, "%s: Failed to offline %s: %s\n", + devname, path, strerror(-rc)); + } + return rc; +} + +static bool memblock_in_dev(struct daxctl_dev *dev, const char *memblock) +{ + struct daxctl_memory *mem = daxctl_dev_get_memory(dev); + const char *mem_base = "/sys/devices/system/memory/"; + unsigned long long memblock_res, dev_start, dev_end; + const char *devname = daxctl_dev_get_devname(dev); + struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + unsigned long memblock_size; + char buf[SYSFS_ATTR_SIZE]; + unsigned long phys_index; + char *index_path; + + if (asprintf(&index_path, "%s/%s/phys_index", mem_base, memblock) < 0) + return false; + + if (sysfs_read_attr(ctx, index_path, buf) == 0) { + phys_index = strtoul(buf, NULL, 16); + if (phys_index == 0 || phys_index == ULONG_MAX) { + err(ctx, "%s: %s: Unable to determine phys_index: %s\n", + devname, memblock, strerror(errno)); + goto out_err; + } + } else { + err(ctx, "%s: %s: Unable to determine phys_index: %s\n", + devname, memblock, strerror(errno)); + goto out_err; + } + + dev_start = daxctl_dev_get_resource(dev); + if (!dev_start) { + err(ctx, "%s: Unable to determine resource\n", devname); + goto out_err; + } + dev_end = dev_start + daxctl_dev_get_size(dev); + + memblock_size = daxctl_memory_get_block_size(mem); + if (!memblock_size) { + err(ctx, "%s: Unable to determine memory block size\n", + devname); + goto out_err; + } + memblock_res = phys_index * memblock_size; + + if (memblock_res >= dev_start && memblock_res <= dev_end) { + free(index_path); + return true; + } + +out_err: + free(index_path); + return false; +} + +static int daxctl_memory_set_state(struct daxctl_memory *mem, + enum memory_state state) +{ + struct daxctl_dev *dev = daxctl_memory_get_dev(mem); + const char *devname = daxctl_dev_get_devname(dev); + struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + const char *node_path; + int rc, changed = 0; + struct dirent *de; + DIR *node_dir; + + node_path = daxctl_memory_get_node_path(mem); + if (!node_path) { + err(ctx, "%s: Failed to get node_path\n", devname); + return -ENXIO; + } + + node_dir = opendir(node_path); + if (!node_dir) + return -errno; + + errno = 0; + while ((de = readdir(node_dir)) != NULL) { + char *mem_path; + + if (strncmp(de->d_name, "memory", 6) == 0) { + if (!memblock_in_dev(dev, de->d_name)) + continue; + rc = asprintf(&mem_path, "%s/%s/state", + node_path, de->d_name); + if (rc < 0) { + rc = -ENOMEM; + goto out_dir; + } + if (state == MEM_ONLINE) + rc = online_one_memblock(dev, mem_path); + else if (state == MEM_OFFLINE) + rc = offline_one_memblock(dev, mem_path); + else + rc = -EINVAL; + free(mem_path); + if (rc < 0) + goto out_dir; + if (rc == 0) + changed++; + } + errno = 0; + } + if (errno) { + rc = -errno; + goto out_dir; + } + rc = changed; + +out_dir: + closedir(node_dir); + return rc; +} + +DAXCTL_EXPORT int daxctl_memory_set_online(struct daxctl_memory *mem) +{ + return daxctl_memory_set_state(mem, MEM_ONLINE); +} + +DAXCTL_EXPORT int daxctl_memory_set_offline(struct daxctl_memory *mem) +{ + return daxctl_memory_set_state(mem, MEM_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_memory_is_online(struct daxctl_memory *mem) +{ + struct daxctl_dev *dev = daxctl_memory_get_dev(mem); + const char *devname = daxctl_dev_get_devname(dev); + struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + int rc, num_online = 0; + const char *node_path; + struct dirent *de; + DIR *node_dir; + + node_path = daxctl_memory_get_node_path(mem); + if (!node_path) { + err(ctx, "%s: Failed to get node_path\n", devname); + return -ENXIO; + } + + node_dir = opendir(node_path); + if (!node_dir) + return -errno; + + errno = 0; + while ((de = readdir(node_dir)) != NULL) { + char *mem_path; + + if (strncmp(de->d_name, "memory", 6) == 0) { + if (!memblock_in_dev(dev, de->d_name)) + continue; + 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); + return rc; +} diff --git a/daxctl/lib/libdaxctl.sym b/daxctl/lib/libdaxctl.sym index 1692624..53eb700 100644 --- a/daxctl/lib/libdaxctl.sym +++ b/daxctl/lib/libdaxctl.sym @@ -59,4 +59,12 @@ global: daxctl_dev_enable_devdax; daxctl_dev_enable_ram; daxctl_dev_get_resource; + daxctl_dev_get_target_node; + daxctl_dev_get_memory; + daxctl_memory_get_dev; + daxctl_memory_get_node_path; + daxctl_memory_get_block_size; + daxctl_memory_set_online; + daxctl_memory_set_offline; + daxctl_memory_is_online; } LIBDAXCTL_5; diff --git a/daxctl/libdaxctl.h b/daxctl/libdaxctl.h index 7214cd3..a5a2bab 100644 --- a/daxctl/libdaxctl.h +++ b/daxctl/libdaxctl.h @@ -73,6 +73,16 @@ 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_get_target_node(struct daxctl_dev *dev); + +struct daxctl_memory; +struct daxctl_memory *daxctl_dev_get_memory(struct daxctl_dev *dev); +struct daxctl_dev *daxctl_memory_get_dev(struct daxctl_memory *mem); +const char *daxctl_memory_get_node_path(struct daxctl_memory *mem); +unsigned long daxctl_memory_get_block_size(struct daxctl_memory *mem); +int daxctl_memory_set_online(struct daxctl_memory *mem); +int daxctl_memory_set_offline(struct daxctl_memory *mem); +int daxctl_memory_is_online(struct daxctl_memory *mem); #define daxctl_dev_foreach(region, dev) \ for (dev = daxctl_dev_get_first(region); \ -- 2.20.1 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm