diff options
Diffstat (limited to 'drivers/dax')
| -rw-r--r-- | drivers/dax/super.c | 191 |
1 files changed, 73 insertions, 118 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 44736cbd446e..fc89e91beea7 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -17,6 +17,24 @@ #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; @@ -40,6 +58,42 @@ void dax_read_unlock(int id) } 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> @@ -65,15 +119,13 @@ struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) 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; @@ -81,29 +133,25 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev, 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; } @@ -112,8 +160,8 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev, 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; } @@ -147,57 +195,32 @@ bool __generic_fsdax_supported(struct dax_device *dax_dev, 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 */ @@ -208,24 +231,6 @@ enum dax_device_flags { 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) { @@ -323,19 +328,6 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages, } 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) { @@ -423,11 +415,6 @@ bool dax_alive(struct dax_device *dax_dev) } 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 @@ -625,38 +612,6 @@ void put_dax(struct dax_device *dax_dev) 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 * |