As of now dax_writeback_mapping_range() takes "struct block_device" as a
parameter and dax_dev is searched from bdev name. This also involves taking
a fresh reference on dax_dev and putting that reference at the end of
function.
We are developing a new filesystem virtio-fs and using dax to access host
page cache directly. But there is no block device. IOW, we want to make
use of dax but want to get rid of this assumption that there is always
a block device associated with dax_dev.
So pass in "struct dax_device" as parameter instead of bdev.
ext2/ext4/xfs are current users and they already have a reference on
dax_device. So there is no need to take reference and drop reference to
dax_device on each call of this function.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Link: https://lore.kernel.org/r/20200103183307.GB13350@redhat.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* on persistent storage prior to completion of the operation.
*/
int dax_writeback_mapping_range(struct address_space *mapping,
- struct block_device *bdev, struct writeback_control *wbc)
+ struct dax_device *dax_dev, struct writeback_control *wbc)
{
XA_STATE(xas, &mapping->i_pages, wbc->range_start >> PAGE_SHIFT);
struct inode *inode = mapping->host;
pgoff_t end_index = wbc->range_end >> PAGE_SHIFT;
- struct dax_device *dax_dev;
void *entry;
int ret = 0;
unsigned int scanned = 0;
if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
return 0;
- dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
- if (!dax_dev)
- return -EIO;
-
trace_dax_writeback_range(inode, xas.xa_index, end_index);
tag_pages_for_writeback(mapping, xas.xa_index, end_index);
xas_lock_irq(&xas);
}
xas_unlock_irq(&xas);
- put_dax(dax_dev);
trace_dax_writeback_range_done(inode, xas.xa_index, end_index);
return ret;
}
static int
ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
- return dax_writeback_mapping_range(mapping,
- mapping->host->i_sb->s_bdev, wbc);
+ struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb);
+
+ return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc);
}
const struct address_space_operations ext2_aops = {
percpu_down_read(&sbi->s_journal_flag_rwsem);
trace_ext4_writepages(inode, wbc);
- ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc);
+ ret = dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc);
trace_ext4_writepages_result(inode, wbc, ret,
nr_to_write - wbc->nr_to_write);
percpu_up_read(&sbi->s_journal_flag_rwsem);
xfs_iflags_clear(ip, XFS_ITRUNCATED);
return dax_writeback_mapping_range(mapping,
- xfs_inode_buftarg(ip)->bt_bdev, wbc);
+ xfs_inode_buftarg(ip)->bt_daxdev, wbc);
}
STATIC sector_t
struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev);
int dax_writeback_mapping_range(struct address_space *mapping,
- struct block_device *bdev, struct writeback_control *wbc);
+ struct dax_device *dax_dev, struct writeback_control *wbc);
struct page *dax_layout_busy_page(struct address_space *mapping);
dax_entry_t dax_lock_page(struct page *page);
}
static inline int dax_writeback_mapping_range(struct address_space *mapping,
- struct block_device *bdev, struct writeback_control *wbc)
+ struct dax_device *dax_dev, struct writeback_control *wbc)
{
return -EOPNOTSUPP;
}