[PATCH v4 61/73] dax: Convert dax_writeback_one to XArray

From: Matthew Wilcox
Date: Tue Dec 05 2017 - 19:44:34 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

Likewise easy

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
fs/dax.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 66f6c4ea18f7..7bd94f1b61d0 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -633,8 +633,7 @@ static int dax_writeback_one(struct block_device *bdev,
struct dax_device *dax_dev, struct address_space *mapping,
pgoff_t index, void *entry)
{
- struct radix_tree_root *pages = &mapping->pages;
- XA_STATE(xas, pages, index);
+ XA_STATE(xas, &mapping->pages, index);
void *entry2, *kaddr;
long ret = 0, id;
sector_t sector;
@@ -649,7 +648,7 @@ static int dax_writeback_one(struct block_device *bdev,
if (WARN_ON(!xa_is_value(entry)))
return -EIO;

- xa_lock_irq(&mapping->pages);
+ xas_lock_irq(&xas);
entry2 = get_unlocked_mapping_entry(&xas);
/* Entry got punched out / reallocated? */
if (!entry2 || WARN_ON_ONCE(!xa_is_value(entry2)))
@@ -668,7 +667,7 @@ static int dax_writeback_one(struct block_device *bdev,
}

/* Another fsync thread may have already written back this entry */
- if (!radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE))
+ if (!xas_get_tag(&xas, PAGECACHE_TAG_TOWRITE))
goto put_unlocked;
/* Lock the entry to serialize with page faults */
entry = lock_slot(&xas);
@@ -679,8 +678,8 @@ static int dax_writeback_one(struct block_device *bdev,
* at the entry only under xa_lock and once they do that they will
* see the entry locked and wait for it to unlock.
*/
- radix_tree_tag_clear(pages, index, PAGECACHE_TAG_TOWRITE);
- xa_unlock_irq(&mapping->pages);
+ xas_clear_tag(&xas, PAGECACHE_TAG_TOWRITE);
+ xas_unlock_irq(&xas);

/*
* Even if dax_writeback_mapping_range() was given a wbc->range_start
@@ -718,9 +717,7 @@ static int dax_writeback_one(struct block_device *bdev,
* the pfn mappings are writeprotected and fault waits for mapping
* entry lock.
*/
- xa_lock_irq(&mapping->pages);
- radix_tree_tag_clear(pages, index, PAGECACHE_TAG_DIRTY);
- xa_unlock_irq(&mapping->pages);
+ xa_clear_tag(&mapping->pages, index, PAGECACHE_TAG_DIRTY);
trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT);
dax_unlock:
dax_read_unlock(id);
@@ -729,7 +726,7 @@ static int dax_writeback_one(struct block_device *bdev,

put_unlocked:
put_unlocked_mapping_entry(&xas, entry2);
- xa_unlock_irq(&mapping->pages);
+ xas_unlock_irq(&xas);
return ret;
}

--
2.15.0