From: Matthew Wilcox <mawil...@microsoft.com>
Replace slot_locked() with dax_locked() and inline unlock_slot() into
its only caller.
Signed-off-by: Matthew Wilcox <mawil...@microsoft.com>
---
fs/dax.c | 48 ++++++++++++++++--------------------------------
1 file changed, 16 insertions(+), 32 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 5097a606da1a..f3463d93a6ce 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -73,6 +73,11 @@ fs_initcall(init_dax_wait_table);
#define DAX_ZERO_PAGE (1UL << 2)
#define DAX_EMPTY (1UL << 3)
+static bool dax_locked(void *entry)
+{
+ return xa_to_value(entry) & DAX_ENTRY_LOCK;
+}
+
static unsigned long dax_radix_sector(void *entry)
{
return xa_to_value(entry) >> DAX_SHIFT;
@@ -180,16 +185,6 @@ static void dax_wake_mapping_entry_waiter(struct
address_space *mapping,
__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
}
-/*
- * Check whether the given slot is locked. Must be called with xa_lock held.
- */
-static inline int slot_locked(struct address_space *mapping, void **slot)
-{
- unsigned long entry = xa_to_value(
- radix_tree_deref_slot_protected(slot, &mapping->pages.xa_lock));
- return entry & DAX_ENTRY_LOCK;
-}
-
/*
* Mark the given slot as locked. Must be called with xa_lock held.
*/
@@ -202,18 +197,6 @@ static inline void *lock_slot(struct address_space
*mapping, void **slot)
return entry;
}
-/*
- * Mark the given slot as unlocked. Must be called with xa_lock held.
- */
-static inline void *unlock_slot(struct address_space *mapping, void **slot)
-{
- unsigned long v = xa_to_value(
- radix_tree_deref_slot_protected(slot, &mapping->pages.xa_lock));
- void *entry = xa_mk_value(v & ~DAX_ENTRY_LOCK);
- radix_tree_replace_slot(&mapping->pages, slot, entry);
- return entry;
-}
-
/*
* Lookup entry in radix tree, wait for it to become unlocked if it is
* a DAX entry and return it. The caller must call
@@ -237,8 +220,7 @@ static void *get_unlocked_mapping_entry(struct
address_space *mapping,
entry = __radix_tree_lookup(&mapping->pages, index, NULL,
&slot);
if (!entry ||
- WARN_ON_ONCE(!xa_is_value(entry)) ||
- !slot_locked(mapping, slot)) {
+ WARN_ON_ONCE(!xa_is_value(entry)) || !dax_locked(entry)) {
if (slotp)
*slotp = slot;
return entry;
@@ -257,17 +239,19 @@ static void *get_unlocked_mapping_entry(struct
address_space *mapping,
static void dax_unlock_mapping_entry(struct address_space *mapping,
pgoff_t index)
{
- void *entry, **slot;
+ XA_STATE(xas, &mapping->pages, index);
+ void *entry;
- xa_lock_irq(&mapping->pages);
- entry = __radix_tree_lookup(&mapping->pages, index, NULL, &slot);
- if (WARN_ON_ONCE(!entry || !xa_is_value(entry) ||
- !slot_locked(mapping, slot))) {
- xa_unlock_irq(&mapping->pages);
+ xas_lock_irq(&xas);
+ entry = xas_load(&xas);
+ if (WARN_ON_ONCE(!entry || !xa_is_value(entry) || !dax_locked(entry))) {
+ xas_unlock_irq(&xas);
return;
}
- unlock_slot(mapping, slot);
- xa_unlock_irq(&mapping->pages);
+ entry = xa_mk_value(xa_to_value(entry) & ~DAX_ENTRY_LOCK);
+ xas_store(&xas, entry);
+ /* Safe to not call xas_pause here -- we don't touch the array after */
+ xas_unlock_irq(&xas);
dax_wake_mapping_entry_waiter(mapping, index, entry, false);
}
--
2.15.1
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