diff options
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 117 |
1 files changed, 35 insertions, 82 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c index 0d435c794d76..2a305c1a2d88 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -18,6 +18,7 @@ #include <linux/module.h> #include <linux/blkpg.h> #include <linux/magic.h> +#include <linux/dax.h> #include <linux/buffer_head.h> #include <linux/swap.h> #include <linux/pagevec.h> @@ -716,50 +717,18 @@ int bdev_write_page(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL_GPL(bdev_write_page); -/** - * bdev_direct_access() - Get the address for directly-accessibly memory - * @bdev: The device containing the memory - * @dax: control and output parameters for ->direct_access - * - * If a block device is made up of directly addressable memory, this function - * will tell the caller the PFN and the address of the memory. The address - * may be directly dereferenced within the kernel without the need to call - * ioremap(), kmap() or similar. The PFN is suitable for inserting into - * page tables. - * - * Return: negative errno if an error occurs, otherwise the number of bytes - * accessible at this address. - */ -long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax) +int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, + pgoff_t *pgoff) { - sector_t sector = dax->sector; - long avail, size = dax->size; - const struct block_device_operations *ops = bdev->bd_disk->fops; + phys_addr_t phys_off = (get_start_sect(bdev) + sector) * 512; - /* - * The device driver is allowed to sleep, in order to make the - * memory directly accessible. - */ - might_sleep(); - - if (size < 0) - return size; - if (!blk_queue_dax(bdev_get_queue(bdev)) || !ops->direct_access) - return -EOPNOTSUPP; - if ((sector + DIV_ROUND_UP(size, 512)) > - part_nr_sects_read(bdev->bd_part)) - return -ERANGE; - sector += get_start_sect(bdev); - if (sector % (PAGE_SIZE / 512)) + if (pgoff) + *pgoff = PHYS_PFN(phys_off); + if (phys_off % PAGE_SIZE || size % PAGE_SIZE) return -EINVAL; - avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size); - if (!avail) - return -ERANGE; - if (avail > 0 && avail & ~PAGE_MASK) - return -ENXIO; - return min(avail, size); + return 0; } -EXPORT_SYMBOL_GPL(bdev_direct_access); +EXPORT_SYMBOL(bdev_dax_pgoff); /** * bdev_dax_supported() - Check if the device supports dax for filesystem @@ -773,62 +742,46 @@ EXPORT_SYMBOL_GPL(bdev_direct_access); */ int bdev_dax_supported(struct super_block *sb, int blocksize) { - struct blk_dax_ctl dax = { - .sector = 0, - .size = PAGE_SIZE, - }; - int err; + struct block_device *bdev = sb->s_bdev; + struct dax_device *dax_dev; + pgoff_t pgoff; + int err, id; + void *kaddr; + pfn_t pfn; + long len; if (blocksize != PAGE_SIZE) { vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax"); return -EINVAL; } - err = bdev_direct_access(sb->s_bdev, &dax); - if (err < 0) { - switch (err) { - case -EOPNOTSUPP: - vfs_msg(sb, KERN_ERR, - "error: device does not support dax"); - break; - case -EINVAL: - vfs_msg(sb, KERN_ERR, - "error: unaligned partition for dax"); - break; - default: - vfs_msg(sb, KERN_ERR, - "error: dax access failed (%d)", err); - } + err = bdev_dax_pgoff(bdev, 0, PAGE_SIZE, &pgoff); + if (err) { + vfs_msg(sb, KERN_ERR, "error: unaligned partition for dax"); return err; } - return 0; -} -EXPORT_SYMBOL_GPL(bdev_dax_supported); - -/** - * bdev_dax_capable() - Return if the raw device is capable for dax - * @bdev: The device for raw block device access - */ -bool bdev_dax_capable(struct block_device *bdev) -{ - struct blk_dax_ctl dax = { - .size = PAGE_SIZE, - }; + dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); + if (!dax_dev) { + vfs_msg(sb, KERN_ERR, "error: device does not support dax"); + return -EOPNOTSUPP; + } - if (!IS_ENABLED(CONFIG_FS_DAX)) - return false; + id = dax_read_lock(); + len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); + dax_read_unlock(id); - dax.sector = 0; - if (bdev_direct_access(bdev, &dax) < 0) - return false; + put_dax(dax_dev); - dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512); - if (bdev_direct_access(bdev, &dax) < 0) - return false; + if (len < 1) { + vfs_msg(sb, KERN_ERR, + "error: dax access failed (%ld)", len); + return len < 0 ? len : -EIO; + } - return true; + return 0; } +EXPORT_SYMBOL_GPL(bdev_dax_supported); /* * pseudo-fs |