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Diffstat (limited to 'module/zfs/zfs_sysfs.c')
| -rw-r--r-- | module/zfs/zfs_sysfs.c | 617 |
1 files changed, 617 insertions, 0 deletions
diff --git a/module/zfs/zfs_sysfs.c b/module/zfs/zfs_sysfs.c new file mode 100644 index 000000000..6bf2e23aa --- /dev/null +++ b/module/zfs/zfs_sysfs.c @@ -0,0 +1,617 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2018 by Delphix. All rights reserved. + */ + +#include <sys/types.h> +#include <sys/param.h> +#include <sys/zfeature.h> +#include <sys/zfs_ioctl.h> +#include <sys/zfs_sysfs.h> +#include <sys/kmem.h> +#include <sys/fs/zfs.h> +#include <linux/kobject.h> + +#include "zfs_prop.h" + +#if !defined(_KERNEL) +#error kernel builds only +#endif + +/* + * ZFS Module sysfs support + * + * This extends our sysfs '/sys/module/zfs' entry to include feature + * and property attributes. The primary consumer of this information + * is user processes, like the zfs CLI, that need to know what the + * current loaded ZFS module supports. The libzfs binary will consult + * this information when instantiating the zfs|zpool property tables + * and the pool features table. + * + * The added top-level directories are: + * /sys/module/zfs + * ├── features.kernel + * ├── features.pool + * ├── properties.dataset + * └── properties.pool + * + * The local interface for the zfs kobjects includes: + * zfs_kobj_init() + * zfs_kobj_add() + * zfs_kobj_release() + * zfs_kobj_add_attr() + * zfs_kobj_fini() + */ + +/* + * A zfs_mod_kobj_t represents a zfs kobject under '/sys/module/zfs' + */ +struct zfs_mod_kobj; +typedef struct zfs_mod_kobj zfs_mod_kobj_t; + +struct zfs_mod_kobj { + struct kobject zko_kobj; + struct kobj_type zko_kobj_type; + struct sysfs_ops zko_sysfs_ops; + size_t zko_attr_count; + struct attribute *zko_attr_list; /* allocated */ + struct attribute **zko_default_attrs; /* allocated */ + size_t zko_child_count; + zfs_mod_kobj_t *zko_children; /* allocated */ +}; + +#define ATTR_TABLE_SIZE(cnt) (sizeof (struct attribute) * (cnt)) +/* Note +1 for NULL terminator slot */ +#define DEFAULT_ATTR_SIZE(cnt) (sizeof (struct attribute *) * (cnt + 1)) +#define CHILD_TABLE_SIZE(cnt) (sizeof (zfs_mod_kobj_t) * (cnt)) + +/* + * These are the top-level kobjects under '/sys/module/zfs/' + */ +static zfs_mod_kobj_t kernel_features_kobj; +static zfs_mod_kobj_t pool_features_kobj; +static zfs_mod_kobj_t dataset_props_kobj; +static zfs_mod_kobj_t pool_props_kobj; + +/* + * The show function is used to provide the content + * of an attribute into a PAGE_SIZE buffer. + */ +typedef ssize_t (*sysfs_show_func)(struct kobject *, struct attribute *, + char *); + +static void +zfs_kobj_fini(zfs_mod_kobj_t *zkobj) +{ + /* finialize any child kobjects */ + if (zkobj->zko_child_count != 0) { + ASSERT(zkobj->zko_children); + for (int i = 0; i < zkobj->zko_child_count; i++) + zfs_kobj_fini(&zkobj->zko_children[i]); + } + + /* kobject_put() will call zfs_kobj_release() to release memory */ + kobject_del(&zkobj->zko_kobj); + kobject_put(&zkobj->zko_kobj); +} + +static void +zfs_kobj_release(struct kobject *kobj) +{ + zfs_mod_kobj_t *zkobj = container_of(kobj, zfs_mod_kobj_t, zko_kobj); + + if (zkobj->zko_attr_count != 0) { + ASSERT(zkobj->zko_attr_list); + ASSERT(zkobj->zko_default_attrs); + + kmem_free(zkobj->zko_attr_list, + ATTR_TABLE_SIZE(zkobj->zko_attr_count)); + kmem_free(zkobj->zko_default_attrs, + DEFAULT_ATTR_SIZE(zkobj->zko_attr_count)); + zkobj->zko_attr_count = 0; + zkobj->zko_attr_list = NULL; + zkobj->zko_default_attrs = NULL; + } + if (zkobj->zko_child_count != 0) { + ASSERT(zkobj->zko_children); + + kmem_free(zkobj->zko_children, + CHILD_TABLE_SIZE(zkobj->zko_child_count)); + zkobj->zko_child_count = 0; + zkobj->zko_children = NULL; + } +} + +static void +zfs_kobj_add_attr(zfs_mod_kobj_t *zkobj, int attr_num, const char *attr_name) +{ + VERIFY3U(attr_num, <, zkobj->zko_attr_count); + ASSERT(zkobj->zko_attr_list); + ASSERT(zkobj->zko_default_attrs); + + zkobj->zko_attr_list[attr_num].name = attr_name; + zkobj->zko_attr_list[attr_num].mode = 0444; + zkobj->zko_default_attrs[attr_num] = &zkobj->zko_attr_list[attr_num]; +} + +static int +zfs_kobj_init(zfs_mod_kobj_t *zkobj, int attr_cnt, int child_cnt, + sysfs_show_func show_func) +{ + /* + * Initialize object's attributes. Count can be zero. + */ + if (attr_cnt > 0) { + zkobj->zko_attr_list = kmem_zalloc(ATTR_TABLE_SIZE(attr_cnt), + KM_SLEEP); + if (zkobj->zko_attr_list == NULL) + return (ENOMEM); + } + /* this will always have at least one slot for NULL termination */ + zkobj->zko_default_attrs = kmem_zalloc(DEFAULT_ATTR_SIZE(attr_cnt), + KM_SLEEP); + if (zkobj->zko_default_attrs == NULL) { + if (zkobj->zko_attr_list) { + kmem_free(zkobj->zko_attr_list, + ATTR_TABLE_SIZE(attr_cnt)); + } + return (ENOMEM); + } + zkobj->zko_attr_count = attr_cnt; + zkobj->zko_kobj_type.default_attrs = zkobj->zko_default_attrs; + + if (child_cnt > 0) { + zkobj->zko_children = kmem_zalloc(CHILD_TABLE_SIZE(child_cnt), + KM_SLEEP); + if (zkobj->zko_children == NULL) { + if (attr_cnt > 0) { + kmem_free(zkobj->zko_attr_list, + DEFAULT_ATTR_SIZE(attr_cnt)); + kmem_free(zkobj->zko_attr_list, + ATTR_TABLE_SIZE(attr_cnt)); + } + return (ENOMEM); + } + zkobj->zko_child_count = child_cnt; + } + + zkobj->zko_sysfs_ops.show = show_func; + zkobj->zko_kobj_type.sysfs_ops = &zkobj->zko_sysfs_ops; + zkobj->zko_kobj_type.release = zfs_kobj_release; + + return (0); +} + +static int +zfs_kobj_add(zfs_mod_kobj_t *zkobj, struct kobject *parent, const char *name) +{ + /* zko_default_attrs must be NULL terminated */ + ASSERT(zkobj->zko_default_attrs != NULL); + ASSERT(zkobj->zko_default_attrs[zkobj->zko_attr_count] == NULL); + + kobject_init(&zkobj->zko_kobj, &zkobj->zko_kobj_type); + return (kobject_add(&zkobj->zko_kobj, parent, name)); +} + +/* + * Each zfs property has these common attributes + */ +static const char *zprop_attrs[] = { + "type", + "readonly", + "setonce", + "visible", + "values", + "default", + "datasets" /* zfs properties only */ +}; + +#define ZFS_PROP_ATTR_COUNT ARRAY_SIZE(zprop_attrs) +#define ZPOOL_PROP_ATTR_COUNT (ZFS_PROP_ATTR_COUNT - 1) + +static const char *zprop_types[] = { + "number", + "string", + "index", +}; + +typedef struct zfs_type_map { + zfs_type_t ztm_type; + const char *ztm_name; +} zfs_type_map_t; + +static zfs_type_map_t type_map[] = { + {ZFS_TYPE_FILESYSTEM, "filesystem"}, + {ZFS_TYPE_SNAPSHOT, "snapshot"}, + {ZFS_TYPE_VOLUME, "volume"}, + {ZFS_TYPE_BOOKMARK, "bookmark"} +}; + +/* + * Show the content for a zfs property attribute + */ +static ssize_t +zprop_sysfs_show(const char *attr_name, const zprop_desc_t *property, + char *buf, size_t buflen) +{ + const char *show_str; + + /* For dataset properties list the dataset types that apply */ + if (strcmp(attr_name, "datasets") == 0 && + property->pd_types != ZFS_TYPE_POOL) { + int len = 0; + + for (int i = 0; i < ARRAY_SIZE(type_map); i++) { + if (type_map[i].ztm_type & property->pd_types) { + len += snprintf(buf + len, buflen - len, "%s ", + type_map[i].ztm_name); + } + } + len += snprintf(buf + len, buflen - len, "\n"); + return (len); + } + + if (strcmp(attr_name, "type") == 0) { + show_str = zprop_types[property->pd_proptype]; + } else if (strcmp(attr_name, "readonly") == 0) { + show_str = property->pd_attr == PROP_READONLY ? "1" : "0"; + } else if (strcmp(attr_name, "setonce") == 0) { + show_str = property->pd_attr == PROP_ONETIME ? "1" : "0"; + } else if (strcmp(attr_name, "visible") == 0) { + show_str = property->pd_visible ? "1" : "0"; + } else if (strcmp(attr_name, "values") == 0) { + show_str = property->pd_values ? property->pd_values : ""; + } else if (strcmp(attr_name, "default") == 0) { + char number[32]; + + switch (property->pd_proptype) { + case PROP_TYPE_NUMBER: + (void) snprintf(number, sizeof (number), "%llu", + (u_longlong_t)property->pd_numdefault); + show_str = number; + break; + case PROP_TYPE_STRING: + show_str = property->pd_strdefault ? + property->pd_strdefault : ""; + break; + case PROP_TYPE_INDEX: + (void) zprop_index_to_string(property->pd_propnum, + property->pd_numdefault, &show_str, + property->pd_types); + break; + default: + return (0); + } + } else { + return (0); + } + + return (snprintf(buf, buflen, "%s\n", show_str)); +} + +static ssize_t +dataset_property_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + zfs_prop_t prop = zfs_name_to_prop(kobject_name(kobj)); + zprop_desc_t *prop_tbl = zfs_prop_get_table(); + ssize_t len; + + ASSERT3U(prop, <, ZFS_NUM_PROPS); + + len = zprop_sysfs_show(attr->name, &prop_tbl[prop], buf, PAGE_SIZE); + + return (len); +} + +static ssize_t +pool_property_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + zpool_prop_t prop = zpool_name_to_prop(kobject_name(kobj)); + zprop_desc_t *prop_tbl = zpool_prop_get_table(); + ssize_t len; + + ASSERT3U(prop, <, ZPOOL_NUM_PROPS); + + len = zprop_sysfs_show(attr->name, &prop_tbl[prop], buf, PAGE_SIZE); + + return (len); +} + +/* + * ZFS kernel feature attributes for '/sys/module/zfs/features.kernel' + * + * This list is intended for kernel features that don't have a pool feature + * association or that extend existing user kernel interfaces. + * + * A user processes can easily check if the running zfs kernel module + * supports the new feature. + * + * For example, the initial channel_program feature was extended to support + * async calls (i.e. a sync flag). If this mechanism were in place at that + * time, we could have added a 'channel_program_async' to this list. + */ +static const char *zfs_features[] = { + /* --> Add new kernel features here (post ZoL 0.8.0) */ +}; + +#define ZFS_FEATURE_COUNT ARRAY_SIZE(zfs_features) + +static ssize_t +kernel_feature_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + return (snprintf(buf, PAGE_SIZE, "supported\n")); +} + +static int +zfs_kernel_features_init(zfs_mod_kobj_t *zfs_kobj, struct kobject *parent) +{ + int err; + + err = zfs_kobj_init(zfs_kobj, ZFS_FEATURE_COUNT, 0, + kernel_feature_show); + if (err) + return (err); + + for (int f = 0; f < ZFS_FEATURE_COUNT; f++) + zfs_kobj_add_attr(zfs_kobj, f, zfs_features[f]); + + err = zfs_kobj_add(zfs_kobj, parent, ZFS_SYSFS_KERNEL_FEATURES); + if (err) + zfs_kobj_release(&zfs_kobj->zko_kobj); + + return (err); +} + +/* + * Each pool feature has these common attributes + */ +static const char *pool_feature_attrs[] = { + "description", + "guid", + "uname", + "readonly_compatible", + "required_for_mos", + "activate_on_enable", + "per_dataset" +}; + +#define ZPOOL_FEATURE_ATTR_COUNT ARRAY_SIZE(pool_feature_attrs) + +/* + * Show the content for the given zfs pool feature attribute + */ +static ssize_t +pool_feature_show(struct kobject *kobj, struct attribute *attr, char *buf) +{ + spa_feature_t fid; + + if (zfeature_lookup_guid(kobject_name(kobj), &fid) != 0) + return (0); + + ASSERT3U(fid, <, SPA_FEATURES); + + zfeature_flags_t flags = spa_feature_table[fid].fi_flags; + const char *show_str = NULL; + + if (strcmp(attr->name, "description") == 0) { + show_str = spa_feature_table[fid].fi_desc; + } else if (strcmp(attr->name, "guid") == 0) { + show_str = spa_feature_table[fid].fi_guid; + } else if (strcmp(attr->name, "uname") == 0) { + show_str = spa_feature_table[fid].fi_uname; + } else if (strcmp(attr->name, "readonly_compatible") == 0) { + show_str = flags & ZFEATURE_FLAG_READONLY_COMPAT ? "1" : "0"; + } else if (strcmp(attr->name, "required_for_mos") == 0) { + show_str = flags & ZFEATURE_FLAG_MOS ? "1" : "0"; + } else if (strcmp(attr->name, "activate_on_enable") == 0) { + show_str = flags & ZFEATURE_FLAG_ACTIVATE_ON_ENABLE ? "1" : "0"; + } else if (strcmp(attr->name, "per_dataset") == 0) { + show_str = flags & ZFEATURE_FLAG_PER_DATASET ? "1" : "0"; + } + if (show_str == NULL) + return (0); + + return (snprintf(buf, PAGE_SIZE, "%s\n", show_str)); +} + +static void +pool_feature_to_kobj(zfs_mod_kobj_t *parent, spa_feature_t fid, + const char *name) +{ + zfs_mod_kobj_t *zfs_kobj = &parent->zko_children[fid]; + + ASSERT3U(fid, <, SPA_FEATURES); + ASSERT(name); + + int err = zfs_kobj_init(zfs_kobj, ZPOOL_FEATURE_ATTR_COUNT, 0, + pool_feature_show); + if (err) + return; + + for (int i = 0; i < ZPOOL_FEATURE_ATTR_COUNT; i++) + zfs_kobj_add_attr(zfs_kobj, i, pool_feature_attrs[i]); + + err = zfs_kobj_add(zfs_kobj, &parent->zko_kobj, name); + if (err) + zfs_kobj_release(&zfs_kobj->zko_kobj); +} + +static int +zfs_pool_features_init(zfs_mod_kobj_t *zfs_kobj, struct kobject *parent) +{ + /* + * Create a parent kobject to host pool features. + * + * '/sys/module/zfs/features.pool' + */ + int err = zfs_kobj_init(zfs_kobj, 0, SPA_FEATURES, pool_feature_show); + if (err) + return (err); + err = zfs_kobj_add(zfs_kobj, parent, ZFS_SYSFS_POOL_FEATURES); + if (err) { + zfs_kobj_release(&zfs_kobj->zko_kobj); + return (err); + } + + /* + * Now create a kobject for each feature. + * + * '/sys/module/zfs/features.pool/<feature>' + */ + for (spa_feature_t i = 0; i < SPA_FEATURES; i++) + pool_feature_to_kobj(zfs_kobj, i, spa_feature_table[i].fi_guid); + + return (0); +} + +typedef struct prop_to_kobj_arg { + zprop_desc_t *p2k_table; + zfs_mod_kobj_t *p2k_parent; + sysfs_show_func p2k_show_func; + int p2k_attr_count; +} prop_to_kobj_arg_t; + +static int +zprop_to_kobj(int prop, void *args) +{ + prop_to_kobj_arg_t *data = args; + zfs_mod_kobj_t *parent = data->p2k_parent; + zfs_mod_kobj_t *zfs_kobj = &parent->zko_children[prop]; + const char *name = data->p2k_table[prop].pd_name; + int err; + + ASSERT(name); + + err = zfs_kobj_init(zfs_kobj, data->p2k_attr_count, 0, + data->p2k_show_func); + if (err) + return (ZPROP_CONT); + + for (int i = 0; i < data->p2k_attr_count; i++) + zfs_kobj_add_attr(zfs_kobj, i, zprop_attrs[i]); + + err = zfs_kobj_add(zfs_kobj, &parent->zko_kobj, name); + if (err) + zfs_kobj_release(&zfs_kobj->zko_kobj); + + return (ZPROP_CONT); +} + +static int +zfs_sysfs_properties_init(zfs_mod_kobj_t *zfs_kobj, struct kobject *parent, + zfs_type_t type) +{ + prop_to_kobj_arg_t context; + const char *name; + int err; + + /* + * Create a parent kobject to host properties. + * + * '/sys/module/zfs/properties.<type>' + */ + if (type == ZFS_TYPE_POOL) { + name = ZFS_SYSFS_POOL_PROPERTIES; + context.p2k_table = zpool_prop_get_table(); + context.p2k_attr_count = ZPOOL_PROP_ATTR_COUNT; + context.p2k_parent = zfs_kobj; + context.p2k_show_func = pool_property_show; + err = zfs_kobj_init(zfs_kobj, 0, ZPOOL_NUM_PROPS, + pool_property_show); + } else { + name = ZFS_SYSFS_DATASET_PROPERTIES; + context.p2k_table = zfs_prop_get_table(); + context.p2k_attr_count = ZFS_PROP_ATTR_COUNT; + context.p2k_parent = zfs_kobj; + context.p2k_show_func = dataset_property_show; + err = zfs_kobj_init(zfs_kobj, 0, ZFS_NUM_PROPS, + dataset_property_show); + } + + if (err) + return (err); + + err = zfs_kobj_add(zfs_kobj, parent, name); + if (err) { + zfs_kobj_release(&zfs_kobj->zko_kobj); + return (err); + } + + /* + * Create a kobject for each property. + * + * '/sys/module/zfs/properties.<type>/<property>' + */ + (void) zprop_iter_common(zprop_to_kobj, &context, B_TRUE, + B_FALSE, type); + + return (err); +} + +void +zfs_sysfs_init(void) +{ + struct kobject *parent = + &(((struct module *)(THIS_MODULE))->mkobj).kobj; + int err; + + ASSERT(parent != NULL); + + err = zfs_kernel_features_init(&kernel_features_kobj, parent); + if (err) + return; + + err = zfs_pool_features_init(&pool_features_kobj, parent); + if (err) { + zfs_kobj_fini(&kernel_features_kobj); + return; + } + + err = zfs_sysfs_properties_init(&pool_props_kobj, parent, + ZFS_TYPE_POOL); + if (err) { + zfs_kobj_fini(&kernel_features_kobj); + zfs_kobj_fini(&pool_features_kobj); + return; + } + + err = zfs_sysfs_properties_init(&dataset_props_kobj, parent, + ZFS_TYPE_FILESYSTEM); + if (err) { + zfs_kobj_fini(&kernel_features_kobj); + zfs_kobj_fini(&pool_features_kobj); + zfs_kobj_fini(&pool_props_kobj); + return; + } +} + +void +zfs_sysfs_fini(void) +{ + /* + * Remove top-level kobjects; each will remove any children kobjects + */ + zfs_kobj_fini(&kernel_features_kobj); + zfs_kobj_fini(&pool_features_kobj); + zfs_kobj_fini(&dataset_props_kobj); + zfs_kobj_fini(&pool_props_kobj); +} |