[PATCH 04/29] dax: simplify the dax_device <-> gendisk association
Replace the dax_host_hash with an xarray indexed by the pointer value
of the gendisk, and require explicitly calls from the block drivers that
want to associate their gendisk with a dax_device.
Signed-off-by: Christoph Hellwig
Acked-by: Mike Snitzer
---
drivers/dax/bus.c| 6 +-
drivers/dax/super.c | 109 +--
drivers/md/dm.c | 6 +-
drivers/nvdimm/pmem.c| 10 +++-
drivers/s390/block/dcssblk.c | 11 +++-
fs/fuse/virtio_fs.c | 2 +-
include/linux/dax.h | 19 --
7 files changed, 66 insertions(+), 97 deletions(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 6cc4da4c713d9..bd7af2f7c5b0a 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1323,10 +1323,10 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data
*data)
}
/*
-* No 'host' or dax_operations since there is no access to this
-* device outside of mmap of the resulting character device.
+* No dax_operations since there is no access to this device outside of
+* mmap of the resulting character device.
*/
- dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
+ dax_dev = alloc_dax(dev_dax, NULL, DAXDEV_F_SYNC);
if (IS_ERR(dax_dev)) {
rc = PTR_ERR(dax_dev);
goto err_alloc_dax;
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index e20d0cef10a18..bf77c3da5d56d 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -7,10 +7,8 @@
#include
#include
#include
-#include
#include
#include
-#include
#include
#include
#include
@@ -21,15 +19,12 @@
* 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;
@@ -42,10 +37,6 @@ static DEFINE_IDA(dax_minor_ida);
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(_srcu);
@@ -58,13 +49,22 @@ void dax_read_unlock(int id)
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
-static int dax_host_hash(const char *host)
+#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
+#include
+
+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(_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL);
}
+EXPORT_SYMBOL_GPL(dax_add_host);
-#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
-#include
+void dax_remove_host(struct gendisk *disk)
+{
+ xa_erase(_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)
@@ -81,41 +81,24 @@ int bdev_dax_pgoff(struct block_device *bdev, sector_t
sector, size_t size,
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(_host_lock);
- hlist_for_each_entry(dax_dev, _host_list[hash], list) {
- if (!dax_alive(dax_dev)
- || strcmp(host, dax_dev->host) != 0)
- continue;
-
- if (igrab(_dev->inode))
- found = dax_dev;
- break;
- }
- spin_unlock(_host_lock);
+ dax_dev = xa_load(_hosts, (unsigned long)bdev->bd_disk);
+ if (!dax_dev || !dax_alive(dax_dev) || !igrab(_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;
-
Re: [PATCH 04/29] dax: simplify the dax_device <-> gendisk association
On Mon, Nov 22, 2021 at 9:58 PM Christoph Hellwig wrote: > > On Mon, Nov 22, 2021 at 07:33:06PM -0800, Dan Williams wrote: > > Is it time to add a "DAX" symbol namespace? > > What would be the benefit? Just the small benefit of identifying DAX core users with a common grep line, and to indicate that DAX exports are more intertwined than standalone exports, but yeah those are minor. ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH 04/29] dax: simplify the dax_device <-> gendisk association
On Mon, Nov 22, 2021 at 07:33:06PM -0800, Dan Williams wrote: > Is it time to add a "DAX" symbol namespace? What would be the benefit? ___ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
Re: [PATCH 04/29] dax: simplify the dax_device <-> gendisk association
On Tue, Nov 9, 2021 at 12:33 AM Christoph Hellwig wrote:
>
> Replace the dax_host_hash with an xarray indexed by the pointer value
> of the gendisk, and require explicitly calls from the block drivers that
> want to associate their gendisk with a dax_device.
>
> Signed-off-by: Christoph Hellwig
> Acked-by: Mike Snitzer
> ---
> drivers/dax/bus.c| 6 +-
> drivers/dax/super.c | 106 +--
> drivers/md/dm.c | 6 +-
> drivers/nvdimm/pmem.c| 8 ++-
> drivers/s390/block/dcssblk.c | 11 +++-
> fs/fuse/virtio_fs.c | 2 +-
> include/linux/dax.h | 19 +--
> 7 files changed, 62 insertions(+), 96 deletions(-)
>
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 6cc4da4c713d9..bd7af2f7c5b0a 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -1323,10 +1323,10 @@ struct dev_dax *devm_create_dev_dax(struct
> dev_dax_data *data)
> }
>
> /*
> -* No 'host' or dax_operations since there is no access to this
> -* device outside of mmap of the resulting character device.
> +* No dax_operations since there is no access to this device outside
> of
> +* mmap of the resulting character device.
> */
> - dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
> + dax_dev = alloc_dax(dev_dax, NULL, DAXDEV_F_SYNC);
> if (IS_ERR(dax_dev)) {
> rc = PTR_ERR(dax_dev);
> goto err_alloc_dax;
> diff --git a/drivers/dax/super.c b/drivers/dax/super.c
> index e20d0cef10a18..9383c11b21853 100644
> --- a/drivers/dax/super.c
> +++ b/drivers/dax/super.c
> @@ -7,10 +7,8 @@
> #include
> #include
> #include
> -#include
> #include
> #include
> -#include
> #include
> #include
> #include
> @@ -26,10 +24,8 @@
> * @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;
> @@ -42,10 +38,6 @@ static DEFINE_IDA(dax_minor_ida);
> 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(_srcu);
> @@ -58,13 +50,22 @@ void dax_read_unlock(int id)
> }
> EXPORT_SYMBOL_GPL(dax_read_unlock);
>
> -static int dax_host_hash(const char *host)
> +#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
> +#include
> +
> +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(_hosts, (unsigned long)disk, dax_dev,
> GFP_KERNEL);
> }
> +EXPORT_SYMBOL_GPL(dax_add_host);
Is it time to add a "DAX" symbol namespace?
>
> -#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
> -#include
> +void dax_remove_host(struct gendisk *disk)
> +{
> + xa_erase(_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)
> @@ -82,40 +83,23 @@ 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
> + * @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(_host_lock);
> - hlist_for_each_entry(dax_dev, _host_list[hash], list) {
> - if (!dax_alive(dax_dev)
> - || strcmp(host, dax_dev->host) != 0)
> - continue;
> -
> - if (igrab(_dev->inode))
> - found = dax_dev;
> - break;
> - }
> - spin_unlock(_host_lock);
> + dax_dev = xa_load(_hosts, (unsigned long)bdev->bd_disk);
> + if (!dax_dev || !dax_alive(dax_dev) || !igrab(_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
[PATCH 04/29] dax: simplify the dax_device <-> gendisk association
Replace the dax_host_hash with an xarray indexed by the pointer value
of the gendisk, and require explicitly calls from the block drivers that
want to associate their gendisk with a dax_device.
Signed-off-by: Christoph Hellwig
Acked-by: Mike Snitzer
---
drivers/dax/bus.c| 6 +-
drivers/dax/super.c | 106 +--
drivers/md/dm.c | 6 +-
drivers/nvdimm/pmem.c| 8 ++-
drivers/s390/block/dcssblk.c | 11 +++-
fs/fuse/virtio_fs.c | 2 +-
include/linux/dax.h | 19 +--
7 files changed, 62 insertions(+), 96 deletions(-)
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 6cc4da4c713d9..bd7af2f7c5b0a 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1323,10 +1323,10 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data
*data)
}
/*
-* No 'host' or dax_operations since there is no access to this
-* device outside of mmap of the resulting character device.
+* No dax_operations since there is no access to this device outside of
+* mmap of the resulting character device.
*/
- dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
+ dax_dev = alloc_dax(dev_dax, NULL, DAXDEV_F_SYNC);
if (IS_ERR(dax_dev)) {
rc = PTR_ERR(dax_dev);
goto err_alloc_dax;
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index e20d0cef10a18..9383c11b21853 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -7,10 +7,8 @@
#include
#include
#include
-#include
#include
#include
-#include
#include
#include
#include
@@ -26,10 +24,8 @@
* @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;
@@ -42,10 +38,6 @@ static DEFINE_IDA(dax_minor_ida);
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(_srcu);
@@ -58,13 +50,22 @@ void dax_read_unlock(int id)
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
-static int dax_host_hash(const char *host)
+#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
+#include
+
+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(_hosts, (unsigned long)disk, dax_dev, GFP_KERNEL);
}
+EXPORT_SYMBOL_GPL(dax_add_host);
-#if defined(CONFIG_BLOCK) && defined(CONFIG_FS_DAX)
-#include
+void dax_remove_host(struct gendisk *disk)
+{
+ xa_erase(_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)
@@ -82,40 +83,23 @@ 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
+ * @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(_host_lock);
- hlist_for_each_entry(dax_dev, _host_list[hash], list) {
- if (!dax_alive(dax_dev)
- || strcmp(host, dax_dev->host) != 0)
- continue;
-
- if (igrab(_dev->inode))
- found = dax_dev;
- break;
- }
- spin_unlock(_host_lock);
+ dax_dev = xa_load(_hosts, (unsigned long)bdev->bd_disk);
+ if (!dax_dev || !dax_alive(dax_dev) || !igrab(_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);
@@ -361,12 +345,7 @@ void kill_dax(struct dax_device *dax_dev)
return;
clear_bit(DAXDEV_ALIVE, _dev->flags);
-
synchronize_srcu(_srcu);
-
- spin_lock(_host_lock);
- hlist_del_init(_dev->list);
- spin_unlock(_host_lock);
}
