#include <linux/fs.h>
#include "dax-private.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 dev_t dax_devt;
DEFINE_STATIC_SRCU(dax_srcu);
static struct vfsmount *dax_mnt;
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
+static int dax_host_hash(const char *host)
+{
+ return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE;
+}
+
+/**
+ * dax_get_by_host() - temporary lookup mechanism for filesystem-dax
+ * @host: alternate name for the device registered by a dax driver
+ */
+static struct dax_device *dax_get_by_host(const char *host)
+{
+ struct dax_device *dax_dev, *found = NULL;
+ int hash, id;
+
+ if (!host)
+ 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_read_unlock(id);
+
+ return found;
+}
+
#ifdef CONFIG_BLOCK
#include <linux/blkdev.h>
return dax_get_by_host(bdev->bd_disk->disk_name);
}
EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
-#endif
-bool __generic_fsdax_supported(struct dax_device *dax_dev,
+bool generic_fsdax_supported(struct dax_device *dax_dev,
struct block_device *bdev, int blocksize, sector_t start,
sector_t sectors)
{
bool dax_enabled = false;
pgoff_t pgoff, pgoff_end;
- char buf[BDEVNAME_SIZE];
void *kaddr, *end_kaddr;
pfn_t pfn, end_pfn;
sector_t last_page;
int err, id;
if (blocksize != PAGE_SIZE) {
- pr_info("%s: error: unsupported blocksize for dax\n",
- bdevname(bdev, buf));
+ pr_info("%pg: error: unsupported blocksize for dax\n", bdev);
return false;
}
if (!dax_dev) {
- pr_debug("%s: error: dax unsupported by block device\n",
- bdevname(bdev, buf));
+ pr_debug("%pg: error: dax unsupported by block device\n", bdev);
return false;
}
err = bdev_dax_pgoff(bdev, start, PAGE_SIZE, &pgoff);
if (err) {
- pr_info("%s: error: unaligned partition for dax\n",
- bdevname(bdev, buf));
+ pr_info("%pg: error: unaligned partition for dax\n", bdev);
return false;
}
last_page = PFN_DOWN((start + sectors - 1) * 512) * PAGE_SIZE / 512;
err = bdev_dax_pgoff(bdev, last_page, PAGE_SIZE, &pgoff_end);
if (err) {
- pr_info("%s: error: unaligned partition for dax\n",
- bdevname(bdev, buf));
+ pr_info("%pg: error: unaligned partition for dax\n", bdev);
return false;
}
len2 = dax_direct_access(dax_dev, pgoff_end, 1, &end_kaddr, &end_pfn);
if (len < 1 || len2 < 1) {
- pr_info("%s: error: dax access failed (%ld)\n",
- bdevname(bdev, buf), len < 1 ? len : len2);
+ pr_info("%pg: error: dax access failed (%ld)\n",
+ bdev, len < 1 ? len : len2);
dax_read_unlock(id);
return false;
}
dax_read_unlock(id);
if (!dax_enabled) {
- pr_info("%s: error: dax support not enabled\n",
- bdevname(bdev, buf));
+ pr_info("%pg: error: dax support not enabled\n", bdev);
return false;
}
return true;
}
-EXPORT_SYMBOL_GPL(__generic_fsdax_supported);
+EXPORT_SYMBOL_GPL(generic_fsdax_supported);
-/**
- * __bdev_dax_supported() - Check if the device supports dax for filesystem
- * @bdev: block device to check
- * @blocksize: The block size of the device
- *
- * This is a library function for filesystems to check if the block device
- * can be mounted with dax option.
- *
- * Return: true if supported, false if unsupported
- */
-bool __bdev_dax_supported(struct block_device *bdev, int blocksize)
+bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
+ int blocksize, sector_t start, sector_t len)
{
- struct dax_device *dax_dev;
- struct request_queue *q;
- char buf[BDEVNAME_SIZE];
- bool ret;
+ bool ret = false;
int id;
- q = bdev_get_queue(bdev);
- if (!q || !blk_queue_dax(q)) {
- pr_debug("%s: error: request queue doesn't support dax\n",
- bdevname(bdev, buf));
- return false;
- }
-
- dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
- if (!dax_dev) {
- pr_debug("%s: error: device does not support dax\n",
- bdevname(bdev, buf));
+ if (!dax_dev)
return false;
- }
id = dax_read_lock();
- ret = dax_supported(dax_dev, bdev, blocksize, 0,
- i_size_read(bdev->bd_inode) / 512);
+ if (dax_alive(dax_dev) && dax_dev->ops->dax_supported)
+ ret = dax_dev->ops->dax_supported(dax_dev, bdev, blocksize,
+ start, len);
dax_read_unlock(id);
-
- put_dax(dax_dev);
-
return ret;
}
-EXPORT_SYMBOL_GPL(__bdev_dax_supported);
-#endif
+EXPORT_SYMBOL_GPL(dax_supported);
+#endif /* CONFIG_FS_DAX */
+#endif /* CONFIG_BLOCK */
enum dax_device_flags {
/* !alive + rcu grace period == no new operations / mappings */
DAXDEV_SYNC,
};
-/**
- * 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 ssize_t write_cache_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
}
EXPORT_SYMBOL_GPL(dax_direct_access);
-bool dax_supported(struct dax_device *dax_dev, struct block_device *bdev,
- int blocksize, sector_t start, sector_t len)
-{
- if (!dax_dev)
- return false;
-
- if (!dax_alive(dax_dev))
- return false;
-
- return dax_dev->ops->dax_supported(dax_dev, bdev, blocksize, start, len);
-}
-EXPORT_SYMBOL_GPL(dax_supported);
-
size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
size_t bytes, struct iov_iter *i)
{
}
EXPORT_SYMBOL_GPL(dax_alive);
-static int dax_host_hash(const char *host)
-{
- return hashlen_hash(hashlen_string("DAX", host)) % DAX_HASH_SIZE;
-}
-
/*
* Note, rcu is not protecting the liveness of dax_dev, rcu is ensuring
* that any fault handlers or operations that might have seen
}
EXPORT_SYMBOL_GPL(put_dax);
-/**
- * dax_get_by_host() - temporary lookup mechanism for filesystem-dax
- * @host: alternate name for the device registered by a dax driver
- */
-struct dax_device *dax_get_by_host(const char *host)
-{
- struct dax_device *dax_dev, *found = NULL;
- int hash, id;
-
- if (!host)
- 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_read_unlock(id);
-
- return found;
-}
-EXPORT_SYMBOL_GPL(dax_get_by_host);
-
/**
* inode_dax: convert a public inode into its dax_dev
* @inode: An inode with i_cdev pointing to a dax_dev
projects / linux-2.6-microblaze.git / blobdiff