mirror of https://gitee.com/openkylin/linux.git
dax: Convert page fault handlers to XArray
This is the last part of DAX to be converted to the XArray so remove all the old helper functions. Signed-off-by: Matthew Wilcox <willy@infradead.org>
This commit is contained in:
Matthew Wilcox
parent
9f32d22130
commit
b15cd80068
433
fs/dax.c
433
fs/dax.c
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@ -93,12 +93,6 @@ static unsigned long dax_to_pfn(void *entry)
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return xa_to_value(entry) >> DAX_SHIFT;
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}
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static void *dax_make_locked(unsigned long pfn, unsigned long flags)
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{
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return xa_mk_value(flags | ((unsigned long)pfn << DAX_SHIFT) |
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DAX_LOCKED);
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}
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static void *dax_make_entry(pfn_t pfn, unsigned long flags)
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{
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return xa_mk_value(flags | (pfn_t_to_pfn(pfn) << DAX_SHIFT));
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@ -155,10 +149,11 @@ struct wait_exceptional_entry_queue {
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struct exceptional_entry_key key;
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};
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static wait_queue_head_t *dax_entry_waitqueue(struct xarray *xa,
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pgoff_t index, void *entry, struct exceptional_entry_key *key)
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static wait_queue_head_t *dax_entry_waitqueue(struct xa_state *xas,
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void *entry, struct exceptional_entry_key *key)
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{
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unsigned long hash;
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unsigned long index = xas->xa_index;
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/*
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* If 'entry' is a PMD, align the 'index' that we use for the wait
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@ -167,11 +162,10 @@ static wait_queue_head_t *dax_entry_waitqueue(struct xarray *xa,
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*/
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if (dax_is_pmd_entry(entry))
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index &= ~PG_PMD_COLOUR;
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key->xa = xa;
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key->xa = xas->xa;
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key->entry_start = index;
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hash = hash_long((unsigned long)xa ^ index, DAX_WAIT_TABLE_BITS);
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hash = hash_long((unsigned long)xas->xa ^ index, DAX_WAIT_TABLE_BITS);
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return wait_table + hash;
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}
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@ -193,13 +187,12 @@ static int wake_exceptional_entry_func(wait_queue_entry_t *wait,
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* The important information it's conveying is whether the entry at
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* this index used to be a PMD entry.
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*/
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static void dax_wake_mapping_entry_waiter(struct xarray *xa,
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pgoff_t index, void *entry, bool wake_all)
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static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all)
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{
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struct exceptional_entry_key key;
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wait_queue_head_t *wq;
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wq = dax_entry_waitqueue(xa, index, entry, &key);
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wq = dax_entry_waitqueue(xas, entry, &key);
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/*
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* Checking for locked entry and prepare_to_wait_exclusive() happens
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@ -211,12 +204,6 @@ static void dax_wake_mapping_entry_waiter(struct xarray *xa,
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__wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key);
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}
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static void dax_wake_entry(struct xa_state *xas, void *entry, bool wake_all)
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{
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return dax_wake_mapping_entry_waiter(xas->xa, xas->xa_index, entry,
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wake_all);
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}
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/*
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* Look up entry in page cache, wait for it to become unlocked if it
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* is a DAX entry and return it. The caller must subsequently call
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@ -241,8 +228,7 @@ static void *get_unlocked_entry(struct xa_state *xas)
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!dax_is_locked(entry))
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return entry;
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wq = dax_entry_waitqueue(xas->xa, xas->xa_index, entry,
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&ewait.key);
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wq = dax_entry_waitqueue(xas, entry, &ewait.key);
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prepare_to_wait_exclusive(wq, &ewait.wait,
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TASK_UNINTERRUPTIBLE);
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xas_unlock_irq(xas);
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@ -286,138 +272,6 @@ static void *dax_lock_entry(struct xa_state *xas, void *entry)
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return xas_store(xas, xa_mk_value(v | DAX_LOCKED));
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}
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/*
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* Check whether the given slot is locked. Must be called with the i_pages
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* lock held.
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*/
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static inline int slot_locked(struct address_space *mapping, void **slot)
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{
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unsigned long entry = xa_to_value(
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radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
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return entry & DAX_LOCKED;
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}
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/*
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* Mark the given slot as locked. Must be called with the i_pages lock held.
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*/
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static inline void *lock_slot(struct address_space *mapping, void **slot)
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{
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unsigned long v = xa_to_value(
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radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
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void *entry = xa_mk_value(v | DAX_LOCKED);
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radix_tree_replace_slot(&mapping->i_pages, slot, entry);
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return entry;
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}
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/*
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* Mark the given slot as unlocked. Must be called with the i_pages lock held.
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*/
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static inline void *unlock_slot(struct address_space *mapping, void **slot)
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{
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unsigned long v = xa_to_value(
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radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock));
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void *entry = xa_mk_value(v & ~DAX_LOCKED);
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radix_tree_replace_slot(&mapping->i_pages, slot, entry);
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return entry;
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}
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/*
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* Lookup entry in page cache, wait for it to become unlocked if it is
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* a DAX entry and return it. The caller must call
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* put_unlocked_mapping_entry() when he decided not to lock the entry or
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* put_locked_mapping_entry() when he locked the entry and now wants to
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* unlock it.
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*
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* Must be called with the i_pages lock held.
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*/
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static void *__get_unlocked_mapping_entry(struct address_space *mapping,
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pgoff_t index, void ***slotp, bool (*wait_fn)(void))
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{
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void *entry, **slot;
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struct wait_exceptional_entry_queue ewait;
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wait_queue_head_t *wq;
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init_wait(&ewait.wait);
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ewait.wait.func = wake_exceptional_entry_func;
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for (;;) {
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bool revalidate;
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entry = __radix_tree_lookup(&mapping->i_pages, index, NULL,
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&slot);
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if (!entry ||
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WARN_ON_ONCE(!xa_is_value(entry)) ||
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!slot_locked(mapping, slot)) {
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if (slotp)
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*slotp = slot;
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return entry;
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}
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wq = dax_entry_waitqueue(&mapping->i_pages, index, entry,
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&ewait.key);
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prepare_to_wait_exclusive(wq, &ewait.wait,
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TASK_UNINTERRUPTIBLE);
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xa_unlock_irq(&mapping->i_pages);
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revalidate = wait_fn();
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finish_wait(wq, &ewait.wait);
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xa_lock_irq(&mapping->i_pages);
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if (revalidate)
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return ERR_PTR(-EAGAIN);
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}
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}
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static bool entry_wait(void)
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{
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schedule();
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/*
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* Never return an ERR_PTR() from
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* __get_unlocked_mapping_entry(), just keep looping.
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*/
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return false;
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}
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static void *get_unlocked_mapping_entry(struct address_space *mapping,
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pgoff_t index, void ***slotp)
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{
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return __get_unlocked_mapping_entry(mapping, index, slotp, entry_wait);
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}
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static void unlock_mapping_entry(struct address_space *mapping, pgoff_t index)
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{
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void *entry, **slot;
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xa_lock_irq(&mapping->i_pages);
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entry = __radix_tree_lookup(&mapping->i_pages, index, NULL, &slot);
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if (WARN_ON_ONCE(!entry || !xa_is_value(entry) ||
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!slot_locked(mapping, slot))) {
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xa_unlock_irq(&mapping->i_pages);
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return;
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}
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unlock_slot(mapping, slot);
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xa_unlock_irq(&mapping->i_pages);
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dax_wake_mapping_entry_waiter(&mapping->i_pages, index, entry, false);
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}
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static void put_locked_mapping_entry(struct address_space *mapping,
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pgoff_t index)
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{
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unlock_mapping_entry(mapping, index);
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}
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/*
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* Called when we are done with page cache entry we looked up via
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* get_unlocked_mapping_entry() and which we didn't lock in the end.
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*/
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static void put_unlocked_mapping_entry(struct address_space *mapping,
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pgoff_t index, void *entry)
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{
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if (!entry)
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return;
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/* We have to wake up next waiter for the page cache entry lock */
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dax_wake_mapping_entry_waiter(&mapping->i_pages, index, entry, false);
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}
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static unsigned long dax_entry_size(void *entry)
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{
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if (dax_is_zero_entry(entry))
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@ -558,47 +412,52 @@ void dax_unlock_mapping_entry(struct page *page)
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* that index, add a locked empty entry.
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*
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* When requesting an entry with size DAX_PMD, grab_mapping_entry() will
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* either return that locked entry or will return an error. This error will
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* happen if there are any 4k entries within the 2MiB range that we are
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* requesting.
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* either return that locked entry or will return VM_FAULT_FALLBACK.
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* This will happen if there are any PTE entries within the PMD range
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* that we are requesting.
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*
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* We always favor 4k entries over 2MiB entries. There isn't a flow where we
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* evict 4k entries in order to 'upgrade' them to a 2MiB entry. A 2MiB
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* insertion will fail if it finds any 4k entries already in the tree, and a
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* 4k insertion will cause an existing 2MiB entry to be unmapped and
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* downgraded to 4k entries. This happens for both 2MiB huge zero pages as
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* well as 2MiB empty entries.
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* We always favor PTE entries over PMD entries. There isn't a flow where we
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* evict PTE entries in order to 'upgrade' them to a PMD entry. A PMD
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* insertion will fail if it finds any PTE entries already in the tree, and a
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* PTE insertion will cause an existing PMD entry to be unmapped and
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* downgraded to PTE entries. This happens for both PMD zero pages as
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* well as PMD empty entries.
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*
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* The exception to this downgrade path is for 2MiB DAX PMD entries that have
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* real storage backing them. We will leave these real 2MiB DAX entries in
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* the tree, and PTE writes will simply dirty the entire 2MiB DAX entry.
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* The exception to this downgrade path is for PMD entries that have
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* real storage backing them. We will leave these real PMD entries in
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* the tree, and PTE writes will simply dirty the entire PMD entry.
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*
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* Note: Unlike filemap_fault() we don't honor FAULT_FLAG_RETRY flags. For
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* persistent memory the benefit is doubtful. We can add that later if we can
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* show it helps.
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*
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* On error, this function does not return an ERR_PTR. Instead it returns
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* a VM_FAULT code, encoded as an xarray internal entry. The ERR_PTR values
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* overlap with xarray value entries.
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*/
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static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
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unsigned long size_flag)
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static void *grab_mapping_entry(struct xa_state *xas,
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struct address_space *mapping, unsigned long size_flag)
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{
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bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */
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void *entry, **slot;
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unsigned long index = xas->xa_index;
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bool pmd_downgrade = false; /* splitting PMD entry into PTE entries? */
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void *entry;
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restart:
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xa_lock_irq(&mapping->i_pages);
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entry = get_unlocked_mapping_entry(mapping, index, &slot);
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if (WARN_ON_ONCE(entry && !xa_is_value(entry))) {
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entry = ERR_PTR(-EIO);
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goto out_unlock;
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}
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retry:
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xas_lock_irq(xas);
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entry = get_unlocked_entry(xas);
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if (xa_is_internal(entry))
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goto fallback;
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if (entry) {
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if (WARN_ON_ONCE(!xa_is_value(entry))) {
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xas_set_err(xas, EIO);
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goto out_unlock;
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}
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if (size_flag & DAX_PMD) {
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if (dax_is_pte_entry(entry)) {
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put_unlocked_mapping_entry(mapping, index,
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entry);
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entry = ERR_PTR(-EEXIST);
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goto out_unlock;
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put_unlocked_entry(xas, entry);
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goto fallback;
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}
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} else { /* trying to grab a PTE entry */
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if (dax_is_pmd_entry(entry) &&
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@ -609,87 +468,57 @@ static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index,
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}
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}
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/* No entry for given index? Make sure radix tree is big enough. */
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if (!entry || pmd_downgrade) {
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int err;
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if (pmd_downgrade) {
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/*
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* Make sure 'entry' remains valid while we drop
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* the i_pages lock.
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*/
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dax_lock_entry(xas, entry);
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if (pmd_downgrade) {
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/*
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* Make sure 'entry' remains valid while we drop
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* the i_pages lock.
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*/
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entry = lock_slot(mapping, slot);
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}
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xa_unlock_irq(&mapping->i_pages);
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/*
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* Besides huge zero pages the only other thing that gets
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* downgraded are empty entries which don't need to be
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* unmapped.
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*/
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if (pmd_downgrade && dax_is_zero_entry(entry))
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unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR,
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PG_PMD_NR, false);
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err = radix_tree_preload(
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mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM);
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if (err) {
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if (pmd_downgrade)
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put_locked_mapping_entry(mapping, index);
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return ERR_PTR(err);
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}
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xa_lock_irq(&mapping->i_pages);
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if (!entry) {
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/*
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* We needed to drop the i_pages lock while calling
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* radix_tree_preload() and we didn't have an entry to
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* lock. See if another thread inserted an entry at
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* our index during this time.
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*/
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entry = __radix_tree_lookup(&mapping->i_pages, index,
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NULL, &slot);
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if (entry) {
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radix_tree_preload_end();
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xa_unlock_irq(&mapping->i_pages);
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goto restart;
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}
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if (dax_is_zero_entry(entry)) {
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xas_unlock_irq(xas);
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unmap_mapping_pages(mapping,
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xas->xa_index & ~PG_PMD_COLOUR,
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PG_PMD_NR, false);
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xas_reset(xas);
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xas_lock_irq(xas);
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}
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if (pmd_downgrade) {
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dax_disassociate_entry(entry, mapping, false);
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radix_tree_delete(&mapping->i_pages, index);
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mapping->nrexceptional--;
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dax_wake_mapping_entry_waiter(&mapping->i_pages,
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index, entry, true);
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}
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entry = dax_make_locked(0, size_flag | DAX_EMPTY);
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err = __radix_tree_insert(&mapping->i_pages, index,
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dax_entry_order(entry), entry);
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radix_tree_preload_end();
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if (err) {
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xa_unlock_irq(&mapping->i_pages);
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/*
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* Our insertion of a DAX entry failed, most likely
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* because we were inserting a PMD entry and it
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* collided with a PTE sized entry at a different
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* index in the PMD range. We haven't inserted
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* anything into the radix tree and have no waiters to
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* wake.
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*/
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return ERR_PTR(err);
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}
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/* Good, we have inserted empty locked entry into the tree. */
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mapping->nrexceptional++;
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xa_unlock_irq(&mapping->i_pages);
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return entry;
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dax_disassociate_entry(entry, mapping, false);
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xas_store(xas, NULL); /* undo the PMD join */
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dax_wake_entry(xas, entry, true);
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mapping->nrexceptional--;
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entry = NULL;
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xas_set(xas, index);
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}
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entry = lock_slot(mapping, slot);
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out_unlock:
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xa_unlock_irq(&mapping->i_pages);
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if (entry) {
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dax_lock_entry(xas, entry);
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} else {
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entry = dax_make_entry(pfn_to_pfn_t(0), size_flag | DAX_EMPTY);
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dax_lock_entry(xas, entry);
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if (xas_error(xas))
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goto out_unlock;
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mapping->nrexceptional++;
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}
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out_unlock:
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xas_unlock_irq(xas);
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if (xas_nomem(xas, mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM))
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goto retry;
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if (xas->xa_node == XA_ERROR(-ENOMEM))
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return xa_mk_internal(VM_FAULT_OOM);
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if (xas_error(xas))
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return xa_mk_internal(VM_FAULT_SIGBUS);
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return entry;
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fallback:
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xas_unlock_irq(xas);
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return xa_mk_internal(VM_FAULT_FALLBACK);
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}
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/**
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@ -847,29 +676,27 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev,
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* already in the tree, we will skip the insertion and just dirty the PMD as
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* appropriate.
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*/
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static void *dax_insert_entry(struct address_space *mapping,
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||||
struct vm_fault *vmf,
|
||||
void *entry, pfn_t pfn_t, unsigned long flags, bool dirty)
|
||||
static void *dax_insert_entry(struct xa_state *xas,
|
||||
struct address_space *mapping, struct vm_fault *vmf,
|
||||
void *entry, pfn_t pfn, unsigned long flags, bool dirty)
|
||||
{
|
||||
struct radix_tree_root *pages = &mapping->i_pages;
|
||||
unsigned long pfn = pfn_t_to_pfn(pfn_t);
|
||||
pgoff_t index = vmf->pgoff;
|
||||
void *new_entry;
|
||||
void *new_entry = dax_make_entry(pfn, flags);
|
||||
|
||||
if (dirty)
|
||||
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
|
||||
|
||||
if (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE)) {
|
||||
unsigned long index = xas->xa_index;
|
||||
/* we are replacing a zero page with block mapping */
|
||||
if (dax_is_pmd_entry(entry))
|
||||
unmap_mapping_pages(mapping, index & ~PG_PMD_COLOUR,
|
||||
PG_PMD_NR, false);
|
||||
PG_PMD_NR, false);
|
||||
else /* pte entry */
|
||||
unmap_mapping_pages(mapping, vmf->pgoff, 1, false);
|
||||
unmap_mapping_pages(mapping, index, 1, false);
|
||||
}
|
||||
|
||||
xa_lock_irq(pages);
|
||||
new_entry = dax_make_locked(pfn, flags);
|
||||
xas_reset(xas);
|
||||
xas_lock_irq(xas);
|
||||
if (dax_entry_size(entry) != dax_entry_size(new_entry)) {
|
||||
dax_disassociate_entry(entry, mapping, false);
|
||||
dax_associate_entry(new_entry, mapping, vmf->vma, vmf->address);
|
||||
|
|
@ -884,21 +711,18 @@ static void *dax_insert_entry(struct address_space *mapping,
|
|||
* existing entry is a PMD, we will just leave the PMD in the
|
||||
* tree and dirty it if necessary.
|
||||
*/
|
||||
struct radix_tree_node *node;
|
||||
void **slot;
|
||||
void *ret;
|
||||
|
||||
ret = __radix_tree_lookup(pages, index, &node, &slot);
|
||||
WARN_ON_ONCE(ret != entry);
|
||||
__radix_tree_replace(pages, node, slot,
|
||||
new_entry, NULL);
|
||||
void *old = dax_lock_entry(xas, new_entry);
|
||||
WARN_ON_ONCE(old != xa_mk_value(xa_to_value(entry) |
|
||||
DAX_LOCKED));
|
||||
entry = new_entry;
|
||||
} else {
|
||||
xas_load(xas); /* Walk the xa_state */
|
||||
}
|
||||
|
||||
if (dirty)
|
||||
radix_tree_tag_set(pages, index, PAGECACHE_TAG_DIRTY);
|
||||
xas_set_mark(xas, PAGECACHE_TAG_DIRTY);
|
||||
|
||||
xa_unlock_irq(pages);
|
||||
xas_unlock_irq(xas);
|
||||
return entry;
|
||||
}
|
||||
|
||||
|
|
@ -1166,15 +990,16 @@ static int dax_iomap_pfn(struct iomap *iomap, loff_t pos, size_t size,
|
|||
* If this page is ever written to we will re-fault and change the mapping to
|
||||
* point to real DAX storage instead.
|
||||
*/
|
||||
static vm_fault_t dax_load_hole(struct address_space *mapping, void *entry,
|
||||
struct vm_fault *vmf)
|
||||
static vm_fault_t dax_load_hole(struct xa_state *xas,
|
||||
struct address_space *mapping, void **entry,
|
||||
struct vm_fault *vmf)
|
||||
{
|
||||
struct inode *inode = mapping->host;
|
||||
unsigned long vaddr = vmf->address;
|
||||
pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr));
|
||||
vm_fault_t ret;
|
||||
|
||||
dax_insert_entry(mapping, vmf, entry, pfn,
|
||||
*entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn,
|
||||
DAX_ZERO_PAGE, false);
|
||||
|
||||
ret = vmf_insert_mixed(vmf->vma, vaddr, pfn);
|
||||
|
|
@ -1384,6 +1209,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
{
|
||||
struct vm_area_struct *vma = vmf->vma;
|
||||
struct address_space *mapping = vma->vm_file->f_mapping;
|
||||
XA_STATE(xas, &mapping->i_pages, vmf->pgoff);
|
||||
struct inode *inode = mapping->host;
|
||||
unsigned long vaddr = vmf->address;
|
||||
loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT;
|
||||
|
|
@ -1410,9 +1236,9 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
if (write && !vmf->cow_page)
|
||||
flags |= IOMAP_WRITE;
|
||||
|
||||
entry = grab_mapping_entry(mapping, vmf->pgoff, 0);
|
||||
if (IS_ERR(entry)) {
|
||||
ret = dax_fault_return(PTR_ERR(entry));
|
||||
entry = grab_mapping_entry(&xas, mapping, 0);
|
||||
if (xa_is_internal(entry)) {
|
||||
ret = xa_to_internal(entry);
|
||||
goto out;
|
||||
}
|
||||
|
||||
|
|
@ -1485,7 +1311,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
if (error < 0)
|
||||
goto error_finish_iomap;
|
||||
|
||||
entry = dax_insert_entry(mapping, vmf, entry, pfn,
|
||||
entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn,
|
||||
0, write && !sync);
|
||||
|
||||
/*
|
||||
|
|
@ -1513,7 +1339,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
case IOMAP_UNWRITTEN:
|
||||
case IOMAP_HOLE:
|
||||
if (!write) {
|
||||
ret = dax_load_hole(mapping, entry, vmf);
|
||||
ret = dax_load_hole(&xas, mapping, &entry, vmf);
|
||||
goto finish_iomap;
|
||||
}
|
||||
/*FALLTHRU*/
|
||||
|
|
@ -1540,21 +1366,20 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap);
|
||||
}
|
||||
unlock_entry:
|
||||
put_locked_mapping_entry(mapping, vmf->pgoff);
|
||||
dax_unlock_entry(&xas, entry);
|
||||
out:
|
||||
trace_dax_pte_fault_done(inode, vmf, ret);
|
||||
return ret | major;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FS_DAX_PMD
|
||||
static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
|
||||
void *entry)
|
||||
static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
|
||||
struct iomap *iomap, void **entry)
|
||||
{
|
||||
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
|
||||
unsigned long pmd_addr = vmf->address & PMD_MASK;
|
||||
struct inode *inode = mapping->host;
|
||||
struct page *zero_page;
|
||||
void *ret = NULL;
|
||||
spinlock_t *ptl;
|
||||
pmd_t pmd_entry;
|
||||
pfn_t pfn;
|
||||
|
|
@ -1565,7 +1390,7 @@ static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
|
|||
goto fallback;
|
||||
|
||||
pfn = page_to_pfn_t(zero_page);
|
||||
ret = dax_insert_entry(mapping, vmf, entry, pfn,
|
||||
*entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn,
|
||||
DAX_PMD | DAX_ZERO_PAGE, false);
|
||||
|
||||
ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd);
|
||||
|
|
@ -1578,11 +1403,11 @@ static vm_fault_t dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap,
|
|||
pmd_entry = pmd_mkhuge(pmd_entry);
|
||||
set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry);
|
||||
spin_unlock(ptl);
|
||||
trace_dax_pmd_load_hole(inode, vmf, zero_page, ret);
|
||||
trace_dax_pmd_load_hole(inode, vmf, zero_page, *entry);
|
||||
return VM_FAULT_NOPAGE;
|
||||
|
||||
fallback:
|
||||
trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, ret);
|
||||
trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, *entry);
|
||||
return VM_FAULT_FALLBACK;
|
||||
}
|
||||
|
||||
|
|
@ -1591,6 +1416,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
{
|
||||
struct vm_area_struct *vma = vmf->vma;
|
||||
struct address_space *mapping = vma->vm_file->f_mapping;
|
||||
XA_STATE_ORDER(xas, &mapping->i_pages, vmf->pgoff, PMD_ORDER);
|
||||
unsigned long pmd_addr = vmf->address & PMD_MASK;
|
||||
bool write = vmf->flags & FAULT_FLAG_WRITE;
|
||||
bool sync;
|
||||
|
|
@ -1598,7 +1424,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
struct inode *inode = mapping->host;
|
||||
vm_fault_t result = VM_FAULT_FALLBACK;
|
||||
struct iomap iomap = { 0 };
|
||||
pgoff_t max_pgoff, pgoff;
|
||||
pgoff_t max_pgoff;
|
||||
void *entry;
|
||||
loff_t pos;
|
||||
int error;
|
||||
|
|
@ -1609,7 +1435,6 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
* supposed to hold locks serializing us with truncate / punch hole so
|
||||
* this is a reliable test.
|
||||
*/
|
||||
pgoff = linear_page_index(vma, pmd_addr);
|
||||
max_pgoff = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
|
||||
|
||||
trace_dax_pmd_fault(inode, vmf, max_pgoff, 0);
|
||||
|
|
@ -1634,24 +1459,26 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
if ((pmd_addr + PMD_SIZE) > vma->vm_end)
|
||||
goto fallback;
|
||||
|
||||
if (pgoff >= max_pgoff) {
|
||||
if (xas.xa_index >= max_pgoff) {
|
||||
result = VM_FAULT_SIGBUS;
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* If the PMD would extend beyond the file size */
|
||||
if ((pgoff | PG_PMD_COLOUR) >= max_pgoff)
|
||||
if ((xas.xa_index | PG_PMD_COLOUR) >= max_pgoff)
|
||||
goto fallback;
|
||||
|
||||
/*
|
||||
* grab_mapping_entry() will make sure we get a 2MiB empty entry, a
|
||||
* 2MiB zero page entry or a DAX PMD. If it can't (because a 4k page
|
||||
* is already in the tree, for instance), it will return -EEXIST and
|
||||
* we just fall back to 4k entries.
|
||||
* grab_mapping_entry() will make sure we get an empty PMD entry,
|
||||
* a zero PMD entry or a DAX PMD. If it can't (because a PTE
|
||||
* entry is already in the array, for instance), it will return
|
||||
* VM_FAULT_FALLBACK.
|
||||
*/
|
||||
entry = grab_mapping_entry(mapping, pgoff, DAX_PMD);
|
||||
if (IS_ERR(entry))
|
||||
entry = grab_mapping_entry(&xas, mapping, DAX_PMD);
|
||||
if (xa_is_internal(entry)) {
|
||||
result = xa_to_internal(entry);
|
||||
goto fallback;
|
||||
}
|
||||
|
||||
/*
|
||||
* It is possible, particularly with mixed reads & writes to private
|
||||
|
|
@ -1670,7 +1497,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
* setting up a mapping, so really we're using iomap_begin() as a way
|
||||
* to look up our filesystem block.
|
||||
*/
|
||||
pos = (loff_t)pgoff << PAGE_SHIFT;
|
||||
pos = (loff_t)xas.xa_index << PAGE_SHIFT;
|
||||
error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap);
|
||||
if (error)
|
||||
goto unlock_entry;
|
||||
|
|
@ -1686,7 +1513,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
if (error < 0)
|
||||
goto finish_iomap;
|
||||
|
||||
entry = dax_insert_entry(mapping, vmf, entry, pfn,
|
||||
entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn,
|
||||
DAX_PMD, write && !sync);
|
||||
|
||||
/*
|
||||
|
|
@ -1711,7 +1538,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
case IOMAP_HOLE:
|
||||
if (WARN_ON_ONCE(write))
|
||||
break;
|
||||
result = dax_pmd_load_hole(vmf, &iomap, entry);
|
||||
result = dax_pmd_load_hole(&xas, vmf, &iomap, &entry);
|
||||
break;
|
||||
default:
|
||||
WARN_ON_ONCE(1);
|
||||
|
|
@ -1734,7 +1561,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
|
|||
&iomap);
|
||||
}
|
||||
unlock_entry:
|
||||
put_locked_mapping_entry(mapping, pgoff);
|
||||
dax_unlock_entry(&xas, entry);
|
||||
fallback:
|
||||
if (result == VM_FAULT_FALLBACK) {
|
||||
split_huge_pmd(vma, vmf->pmd, vmf->address);
|
||||
|
|
|
|||
Loading…
Reference in New Issue