#include <linux/mount.h>
#include <linux/pseudo_fs.h>
#include <linux/magic.h>
-#include <linux/genhd.h>
#include <linux/pfn_t.h>
#include <linux/cdev.h>
-#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/uio.h>
#include <linux/dax.h>
* struct dax_device - anchor object for dax services
* @inode: core vfs
* @cdev: optional character interface for "device dax"
- * @host: optional name for lookups where the device path is not available
* @private: dax driver private data
* @flags: state and boolean properties
*/
struct dax_device {
- struct hlist_node list;
struct inode inode;
struct cdev cdev;
- const char *host;
void *private;
unsigned long flags;
const struct dax_operations *ops;
static struct kmem_cache *dax_cache __read_mostly;
static struct super_block *dax_superblock __read_mostly;
-#define DAX_HASH_SIZE (PAGE_SIZE / sizeof(struct hlist_head))
-static struct hlist_head dax_host_list[DAX_HASH_SIZE];
-static DEFINE_SPINLOCK(dax_host_lock);
-
int dax_read_lock(void)
{
return srcu_read_lock(&dax_srcu);
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
-static int dax_host_hash(const char *host)
+#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
+#include <linux/blkdev.h>
+
+static DEFINE_XARRAY(dax_hosts);
+
+int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk)
{
- return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE;
+ return xa_insert(&dax_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL);
}
+EXPORT_SYMBOL_GPL(dax_add_host);
-#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
-#include <linux/blkdev.h>
+void dax_remove_host(struct gendisk *disk)
+{
+ xa_erase(&dax_hosts, (unsigned long)disk);
+}
+EXPORT_SYMBOL_GPL(dax_remove_host);
int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size,
pgoff_t *pgoff)
EXPORT_SYMBOL(bdev_dax_pgoff);
/**
- * dax_get_by_host() - temporary lookup mechanism for filesystem-dax
- * @host: alternate name for the device registered by a dax driver
+ * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax
+ * @bdev: block device to find a dax_device for
*/
-static struct dax_device *dax_get_by_host(const char *host)
+struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
{
- struct dax_device *dax_dev, *found = NULL;
- int hash, id;
+ struct dax_device *dax_dev;
+ int id;
- if (!host)
+ if (!blk_queue_dax(bdev->bd_disk->queue))
return NULL;
- hash = dax_host_hash(host);
-
id = dax_read_lock();
- spin_lock(&dax_host_lock);
- hlist_for_each_entry(dax_dev, &dax_host_list[hash], list) {
- if (!dax_alive(dax_dev)
- || strcmp(host, dax_dev->host) != 0)
- continue;
-
- if (igrab(&dax_dev->inode))
- found = dax_dev;
- break;
- }
- spin_unlock(&dax_host_lock);
+ dax_dev = xa_load(&dax_hosts, (unsigned long)bdev->bd_disk);
+ if (!dax_dev || !dax_alive(dax_dev) || !igrab(&dax_dev->inode))
+ dax_dev = NULL;
dax_read_unlock(id);
- return found;
-}
-
-struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
-{
- if (!blk_queue_dax(bdev->bd_disk->queue))
- return NULL;
- return dax_get_by_host(bdev->bd_disk->disk_name);
+ return dax_dev;
}
EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
return;
clear_bit(DAXDEV_ALIVE, &dax_dev->flags);
-
synchronize_srcu(&dax_srcu);
-
- spin_lock(&dax_host_lock);
- hlist_del_init(&dax_dev->list);
- spin_unlock(&dax_host_lock);
}
EXPORT_SYMBOL_GPL(kill_dax);
static void dax_free_inode(struct inode *inode)
{
struct dax_device *dax_dev = to_dax_dev(inode);
- kfree(dax_dev->host);
- dax_dev->host = NULL;
if (inode->i_rdev)
ida_simple_remove(&dax_minor_ida, iminor(inode));
kmem_cache_free(dax_cache, dax_dev);
return dax_dev;
}
-static void dax_add_host(struct dax_device *dax_dev, const char *host)
-{
- int hash;
-
- /*
- * Unconditionally init dax_dev since it's coming from a
- * non-zeroed slab cache
- */
- INIT_HLIST_NODE(&dax_dev->list);
- dax_dev->host = host;
- if (!host)
- return;
-
- hash = dax_host_hash(host);
- spin_lock(&dax_host_lock);
- hlist_add_head(&dax_dev->list, &dax_host_list[hash]);
- spin_unlock(&dax_host_lock);
-}
-
-struct dax_device *alloc_dax(void *private, const char *__host,
- const struct dax_operations *ops, unsigned long flags)
+struct dax_device *alloc_dax(void *private, const struct dax_operations *ops,
+ unsigned long flags)
{
struct dax_device *dax_dev;
- const char *host;
dev_t devt;
int minor;
- if (ops && !ops->zero_page_range) {
- pr_debug("%s: error: device does not provide dax"
- " operation zero_page_range()\n",
- __host ? __host : "Unknown");
+ if (WARN_ON_ONCE(ops && !ops->zero_page_range))
return ERR_PTR(-EINVAL);
- }
-
- host = kstrdup(__host, GFP_KERNEL);
- if (__host && !host)
- return ERR_PTR(-ENOMEM);
minor = ida_simple_get(&dax_minor_ida, 0, MINORMASK+1, GFP_KERNEL);
if (minor < 0)
- goto err_minor;
+ return ERR_PTR(-ENOMEM);
devt = MKDEV(MAJOR(dax_devt), minor);
dax_dev = dax_dev_get(devt);
if (!dax_dev)
goto err_dev;
- dax_add_host(dax_dev, host);
dax_dev->ops = ops;
dax_dev->private = private;
if (flags & DAXDEV_F_SYNC)
err_dev:
ida_simple_remove(&dax_minor_ida, minor);
- err_minor:
- kfree(host);
return ERR_PTR(-ENOMEM);
}
EXPORT_SYMBOL_GPL(alloc_dax);
typedef unsigned long dax_entry_t;
+struct dax_device;
+struct gendisk;
struct iomap_ops;
struct iomap;
-struct dax_device;
+
struct dax_operations {
/*
* direct_access: translate a device-relative
};
#if IS_ENABLED(CONFIG_DAX)
-struct dax_device *alloc_dax(void *private, const char *host,
- const struct dax_operations *ops, unsigned long flags);
+struct dax_device *alloc_dax(void *private, const struct dax_operations *ops,
+ unsigned long flags);
void put_dax(struct dax_device *dax_dev);
void kill_dax(struct dax_device *dax_dev);
void dax_write_cache(struct dax_device *dax_dev, bool wc);
return dax_synchronous(dax_dev);
}
#else
-static inline struct dax_device *alloc_dax(void *private, const char *host,
+static inline struct dax_device *alloc_dax(void *private,
const struct dax_operations *ops, unsigned long flags)
{
/*
struct writeback_control;
int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff);
#if IS_ENABLED(CONFIG_FS_DAX)
+int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk);
+void dax_remove_host(struct gendisk *disk);
bool generic_fsdax_supported(struct dax_device *dax_dev,
struct block_device *bdev, int blocksize, sector_t start,
sector_t sectors);
dax_entry_t dax_lock_page(struct page *page);
void dax_unlock_page(struct page *page, dax_entry_t cookie);
#else
+static inline int dax_add_host(struct dax_device *dax_dev, struct gendisk *disk)
+{
+ return 0;
+}
+static inline void dax_remove_host(struct gendisk *disk)
+{
+}
#define generic_fsdax_supported NULL
static inline bool dax_supported(struct dax_device *dax_dev,