[PATCH v2 13/30] dax: Pass dax_dev to dax_writeback_mapping_range()

From: Vivek Goyal
Date: Wed May 15 2019 - 15:32:56 EST


Right now dax_writeback_mapping_range() is passed a bdev and dax_dev
is searched from that bdev name.

virtio-fs does not have a bdev. So pass in dax_dev also to
dax_writeback_mapping_range(). If dax_dev is passed in, bdev is not
used otherwise dax_dev is searched using bdev.

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
fs/dax.c | 16 ++++++++++------
fs/ext2/inode.c | 2 +-
fs/ext4/inode.c | 2 +-
fs/xfs/xfs_aops.c | 2 +-
include/linux/dax.h | 6 ++++--
5 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 815bc32fd967..c944c1efc78f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -932,12 +932,12 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev,
* 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 block_device *bdev, 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;
@@ -948,9 +948,12 @@ int dax_writeback_mapping_range(struct address_space *mapping,
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;
+ if (bdev) {
+ WARN_ON(dax_dev);
+ 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);

@@ -972,7 +975,8 @@ int dax_writeback_mapping_range(struct address_space *mapping,
xas_lock_irq(&xas);
}
xas_unlock_irq(&xas);
- put_dax(dax_dev);
+ if (bdev)
+ put_dax(dax_dev);
trace_dax_writeback_range_done(inode, xas.xa_index, end_index);
return ret;
}
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index c27c27300d95..9b0131c53429 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -956,7 +956,7 @@ 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);
+ mapping->host->i_sb->s_bdev, NULL, wbc);
}

const struct address_space_operations ext2_aops = {
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b32a57bc5d5d..cb8cf5eddd9b 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2972,7 +2972,7 @@ static int ext4_dax_writepages(struct address_space *mapping,
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, inode->i_sb->s_bdev, NULL, wbc);
trace_ext4_writepages_result(inode, wbc, ret,
nr_to_write - wbc->nr_to_write);
percpu_up_read(&sbi->s_journal_flag_rwsem);
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 3619e9e8d359..27f71ff55096 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -994,7 +994,7 @@ xfs_dax_writepages(
{
xfs_iflags_clear(XFS_I(mapping->host), XFS_ITRUNCATED);
return dax_writeback_mapping_range(mapping,
- xfs_find_bdev_for_inode(mapping->host), wbc);
+ xfs_find_bdev_for_inode(mapping->host), NULL, wbc);
}

STATIC int
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 0dd316a74a29..bf3b00b5f0bf 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -87,7 +87,8 @@ static inline void fs_put_dax(struct dax_device *dax_dev)

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 block_device *bdev, 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);
@@ -119,7 +120,8 @@ static inline struct page *dax_layout_busy_page(struct address_space *mapping)
}

static inline int dax_writeback_mapping_range(struct address_space *mapping,
- struct block_device *bdev, struct writeback_control *wbc)
+ struct block_device *bdev, struct dax_device *dax_dev,
+ struct writeback_control *wbc)
{
return -EOPNOTSUPP;
}
--
2.20.1