From: Matthew Wilcox <mawil...@microsoft.com>
Signed-off-by: Matthew Wilcox <mawil...@microsoft.com>
---
fs/dax.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 03bfa599f75c..d2007a17d257 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -188,15 +188,13 @@ static void dax_wake_mapping_entry_waiter(struct
address_space *mapping,
}
/*
- * Mark the given slot is locked. The function must be called with
- * mapping xa_lock held
+ * Mark the given slot as locked. Must be called with xa_lock held.
*/
-static inline void *lock_slot(struct address_space *mapping, void **slot)
+static inline void *lock_slot(struct xa_state *xas)
{
- unsigned long v = xa_to_value(
- radix_tree_deref_slot_protected(slot, &mapping->pages.xa_lock));
+ unsigned long v = xa_to_value(xas_load(xas));
void *entry = xa_mk_value(v | DAX_ENTRY_LOCK);
- radix_tree_replace_slot(&mapping->pages, slot, entry);
+ xas_store(xas, entry);
return entry;
}
@@ -247,7 +245,7 @@ static void dax_unlock_mapping_entry(struct address_space
*mapping,
xas_lock_irq(&xas);
entry = xas_load(&xas);
- if (WARN_ON_ONCE(!entry || !xa_is_value(entry) || !dax_locked(entry))) {
+ if (WARN_ON_ONCE(!xa_is_value(entry) || !dax_locked(entry))) {
xas_unlock_irq(&xas);
return;
}
@@ -306,6 +304,7 @@ static void put_unlocked_mapping_entry(struct address_space
*mapping,
static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
unsigned long size_flag)
{
+ XA_STATE(xas, &mapping->pages, index);
bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */
void *entry, **slot;
@@ -344,7 +343,7 @@ static void *grab_mapping_entry(struct address_space
*mapping, pgoff_t index,
* Make sure 'entry' remains valid while we drop
* mapping xa_lock.
*/
- entry = lock_slot(mapping, slot);
+ entry = lock_slot(&xas);
}
xa_unlock_irq(&mapping->pages);
@@ -411,7 +410,7 @@ static void *grab_mapping_entry(struct address_space
*mapping, pgoff_t index,
xa_unlock_irq(&mapping->pages);
return entry;
}
- entry = lock_slot(mapping, slot);
+ entry = lock_slot(&xas);
out_unlock:
xa_unlock_irq(&mapping->pages);
return entry;
@@ -643,6 +642,7 @@ static int dax_writeback_one(struct block_device *bdev,
pgoff_t index, void *entry)
{
struct radix_tree_root *pages = &mapping->pages;
+ XA_STATE(xas, pages, index);
void *entry2, **slot, *kaddr;
long ret = 0, id;
sector_t sector;
@@ -679,7 +679,7 @@ static int dax_writeback_one(struct block_device *bdev,
if (!radix_tree_tag_get(pages, index, PAGECACHE_TAG_TOWRITE))
goto put_unlocked;
/* Lock the entry to serialize with page faults */
- entry = lock_slot(mapping, slot);
+ entry = lock_slot(&xas);
/*
* We can clear the tag now but we have to be careful so that concurrent
* dax_writeback_one() calls for the same index cannot finish before we
@@ -1504,8 +1504,9 @@ static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
pfn_t pfn)
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
- void *entry, **slot;
pgoff_t index = vmf->pgoff;
+ XA_STATE(xas, &mapping->pages, index);
+ void *entry, **slot;
int vmf_ret, error;
xa_lock_irq(&mapping->pages);
@@ -1521,7 +1522,7 @@ static int dax_insert_pfn_mkwrite(struct vm_fault *vmf,
return VM_FAULT_NOPAGE;
}
radix_tree_tag_set(&mapping->pages, index, PAGECACHE_TAG_DIRTY);
- entry = lock_slot(mapping, slot);
+ entry = lock_slot(&xas);
xa_unlock_irq(&mapping->pages);
switch (pe_size) {
case PE_SIZE_PTE:
--
2.15.0
--
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