Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * zpool memory storage api
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2014 Dan Streetman
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * This is a common frontend for memory storage pool implementations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * Typically, this is used to store compressed memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/spinlock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/zpool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) struct zpool {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	struct zpool_driver *driver;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 	void *pool;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 	const struct zpool_ops *ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 	bool evictable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) static LIST_HEAD(drivers_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) static DEFINE_SPINLOCK(drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) static LIST_HEAD(pools_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static DEFINE_SPINLOCK(pools_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37)  * zpool_register_driver() - register a zpool implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38)  * @driver:	driver to register
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) void zpool_register_driver(struct zpool_driver *driver)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	spin_lock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	atomic_set(&driver->refcount, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	list_add(&driver->list, &drivers_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	spin_unlock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) EXPORT_SYMBOL(zpool_register_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50)  * zpool_unregister_driver() - unregister a zpool implementation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  * @driver:	driver to unregister.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)  * Module usage counting is used to prevent using a driver
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  * while/after unloading, so if this is called from module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55)  * exit function, this should never fail; if called from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56)  * other than the module exit function, and this returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57)  * failure, the driver is in use and must remain available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) int zpool_unregister_driver(struct zpool_driver *driver)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	int ret = 0, refcount;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	spin_lock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	refcount = atomic_read(&driver->refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	WARN_ON(refcount < 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	if (refcount > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		ret = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		list_del(&driver->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	spin_unlock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) EXPORT_SYMBOL(zpool_unregister_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) /* this assumes @type is null-terminated. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) static struct zpool_driver *zpool_get_driver(const char *type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	struct zpool_driver *driver;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	spin_lock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	list_for_each_entry(driver, &drivers_head, list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		if (!strcmp(driver->type, type)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			bool got = try_module_get(driver->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 			if (got)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 				atomic_inc(&driver->refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 			spin_unlock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 			return got ? driver : NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	spin_unlock(&drivers_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) static void zpool_put_driver(struct zpool_driver *driver)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	atomic_dec(&driver->refcount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	module_put(driver->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)  * zpool_has_pool() - Check if the pool driver is available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)  * @type:	The type of the zpool to check (e.g. zbud, zsmalloc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)  * This checks if the @type pool driver is available.  This will try to load
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)  * the requested module, if needed, but there is no guarantee the module will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)  * still be loaded and available immediately after calling.  If this returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)  * true, the caller should assume the pool is available, but must be prepared
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)  * to handle the @zpool_create_pool() returning failure.  However if this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)  * returns false, the caller should assume the requested pool type is not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)  * available; either the requested pool type module does not exist, or could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)  * not be loaded, and calling @zpool_create_pool() with the pool type will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)  * fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)  * The @type string must be null-terminated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)  * Returns: true if @type pool is available, false if not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) bool zpool_has_pool(char *type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	struct zpool_driver *driver = zpool_get_driver(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (!driver) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		request_module("zpool-%s", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		driver = zpool_get_driver(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	if (!driver)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	zpool_put_driver(driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) EXPORT_SYMBOL(zpool_has_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)  * zpool_create_pool() - Create a new zpool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * @type:	The type of the zpool to create (e.g. zbud, zsmalloc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * @name:	The name of the zpool (e.g. zram0, zswap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  * @gfp:	The GFP flags to use when allocating the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)  * @ops:	The optional ops callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)  * This creates a new zpool of the specified type.  The gfp flags will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)  * used when allocating memory, if the implementation supports it.  If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)  * ops param is NULL, then the created zpool will not be evictable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)  * Implementations must guarantee this to be thread-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)  * The @type and @name strings must be null-terminated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)  * Returns: New zpool on success, NULL on failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) struct zpool *zpool_create_pool(const char *type, const char *name, gfp_t gfp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		const struct zpool_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	struct zpool_driver *driver;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	struct zpool *zpool;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	pr_debug("creating pool type %s\n", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	driver = zpool_get_driver(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	if (!driver) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		request_module("zpool-%s", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		driver = zpool_get_driver(type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	if (!driver) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		pr_err("no driver for type %s\n", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	zpool = kmalloc(sizeof(*zpool), gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	if (!zpool) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 		pr_err("couldn't create zpool - out of memory\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		zpool_put_driver(driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	zpool->driver = driver;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	zpool->pool = driver->create(name, gfp, ops, zpool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	zpool->ops = ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	zpool->evictable = driver->shrink && ops && ops->evict;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	if (!zpool->pool) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		pr_err("couldn't create %s pool\n", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		zpool_put_driver(driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		kfree(zpool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	pr_debug("created pool type %s\n", type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	spin_lock(&pools_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	list_add(&zpool->list, &pools_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	spin_unlock(&pools_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	return zpool;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204)  * zpool_destroy_pool() - Destroy a zpool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)  * @zpool:	The zpool to destroy.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)  * Implementations must guarantee this to be thread-safe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208)  * however only when destroying different pools.  The same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)  * pool should only be destroyed once, and should not be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)  * after it is destroyed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)  * This destroys an existing zpool.  The zpool should not be in use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) void zpool_destroy_pool(struct zpool *zpool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	pr_debug("destroying pool type %s\n", zpool->driver->type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	spin_lock(&pools_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	list_del(&zpool->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	spin_unlock(&pools_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	zpool->driver->destroy(zpool->pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	zpool_put_driver(zpool->driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	kfree(zpool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)  * zpool_get_type() - Get the type of the zpool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)  * @zpool:	The zpool to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)  * This returns the type of the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)  * Implementations must guarantee this to be thread-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)  * Returns: The type of zpool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) const char *zpool_get_type(struct zpool *zpool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	return zpool->driver->type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)  * zpool_malloc_support_movable() - Check if the zpool supports
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)  *	allocating movable memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)  * @zpool:	The zpool to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)  * This returns if the zpool supports allocating movable memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)  * Implementations must guarantee this to be thread-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)  * Returns: true if the zpool supports allocating movable memory, false if not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) bool zpool_malloc_support_movable(struct zpool *zpool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	return zpool->driver->malloc_support_movable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)  * zpool_malloc() - Allocate memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)  * @zpool:	The zpool to allocate from.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  * @size:	The amount of memory to allocate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)  * @gfp:	The GFP flags to use when allocating memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)  * @handle:	Pointer to the handle to set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)  * This allocates the requested amount of memory from the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)  * The gfp flags will be used when allocating memory, if the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266)  * implementation supports it.  The provided @handle will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)  * set to the allocated object handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269)  * Implementations must guarantee this to be thread-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)  * Returns: 0 on success, negative value on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) int zpool_malloc(struct zpool *zpool, size_t size, gfp_t gfp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 			unsigned long *handle)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	return zpool->driver->malloc(zpool->pool, size, gfp, handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)  * zpool_free() - Free previously allocated memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)  * @zpool:	The zpool that allocated the memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)  * @handle:	The handle to the memory to free.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284)  * This frees previously allocated memory.  This does not guarantee
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)  * that the pool will actually free memory, only that the memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)  * in the pool will become available for use by the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)  * Implementations must guarantee this to be thread-safe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)  * however only when freeing different handles.  The same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)  * handle should only be freed once, and should not be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)  * after freeing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) void zpool_free(struct zpool *zpool, unsigned long handle)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	zpool->driver->free(zpool->pool, handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)  * zpool_shrink() - Shrink the pool size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)  * @zpool:	The zpool to shrink.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)  * @pages:	The number of pages to shrink the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)  * @reclaimed:	The number of pages successfully evicted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)  * This attempts to shrink the actual memory size of the pool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305)  * by evicting currently used handle(s).  If the pool was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306)  * created with no zpool_ops, or the evict call fails for any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)  * of the handles, this will fail.  If non-NULL, the @reclaimed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)  * parameter will be set to the number of pages reclaimed,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)  * which may be more than the number of pages requested.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)  * Implementations must guarantee this to be thread-safe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)  * Returns: 0 on success, negative value on error/failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) int zpool_shrink(struct zpool *zpool, unsigned int pages,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 			unsigned int *reclaimed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 	return zpool->driver->shrink ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	       zpool->driver->shrink(zpool->pool, pages, reclaimed) : -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)  * zpool_map_handle() - Map a previously allocated handle into memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324)  * @zpool:	The zpool that the handle was allocated from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)  * @handle:	The handle to map
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)  * @mapmode:	How the memory should be mapped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)  * This maps a previously allocated handle into memory.  The @mapmode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329)  * param indicates to the implementation how the memory will be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330)  * used, i.e. read-only, write-only, read-write.  If the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)  * implementation does not support it, the memory will be treated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)  * as read-write.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)  * This may hold locks, disable interrupts, and/or preemption,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335)  * and the zpool_unmap_handle() must be called to undo those
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336)  * actions.  The code that uses the mapped handle should complete
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)  * its operatons on the mapped handle memory quickly and unmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)  * as soon as possible.  As the implementation may use per-cpu
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)  * data, multiple handles should not be mapped concurrently on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)  * any cpu.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)  * Returns: A pointer to the handle's mapped memory area.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) void *zpool_map_handle(struct zpool *zpool, unsigned long handle,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 			enum zpool_mapmode mapmode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	return zpool->driver->map(zpool->pool, handle, mapmode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)  * zpool_unmap_handle() - Unmap a previously mapped handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352)  * @zpool:	The zpool that the handle was allocated from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)  * @handle:	The handle to unmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355)  * This unmaps a previously mapped handle.  Any locks or other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356)  * actions that the implementation took in zpool_map_handle()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)  * will be undone here.  The memory area returned from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)  * zpool_map_handle() should no longer be used after this.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) void zpool_unmap_handle(struct zpool *zpool, unsigned long handle)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	zpool->driver->unmap(zpool->pool, handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)  * zpool_get_total_size() - The total size of the pool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)  * @zpool:	The zpool to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)  * This returns the total size in bytes of the pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)  * Returns: Total size of the zpool in bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) u64 zpool_get_total_size(struct zpool *zpool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 	return zpool->driver->total_size(zpool->pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)  * zpool_evictable() - Test if zpool is potentially evictable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380)  * @zpool:	The zpool to test
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)  * Zpool is only potentially evictable when it's created with struct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)  * zpool_ops.evict and its driver implements struct zpool_driver.shrink.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)  * However, it doesn't necessarily mean driver will use zpool_ops.evict
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386)  * in its implementation of zpool_driver.shrink. It could do internal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387)  * defragmentation instead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)  * Returns: true if potentially evictable; false otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) bool zpool_evictable(struct zpool *zpool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 	return zpool->evictable;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) MODULE_DESCRIPTION("Common API for compressed memory storage");