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Diffstat (limited to 'mm/filemap.c')
-rw-r--r--mm/filemap.c175
1 files changed, 94 insertions, 81 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 8a287dfc5372..68f1813fbdc3 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -110,36 +110,94 @@
* ->tasklist_lock (memory_failure, collect_procs_ao)
*/
+static int page_cache_tree_insert(struct address_space *mapping,
+ struct page *page, void **shadowp)
+{
+ struct radix_tree_node *node;
+ void **slot;
+ int error;
+
+ error = __radix_tree_create(&mapping->page_tree, page->index, 0,
+ &node, &slot);
+ if (error)
+ return error;
+ if (*slot) {
+ void *p;
+
+ p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
+ if (!radix_tree_exceptional_entry(p))
+ return -EEXIST;
+
+ mapping->nrexceptional--;
+ if (!dax_mapping(mapping)) {
+ if (shadowp)
+ *shadowp = p;
+ if (node)
+ workingset_node_shadows_dec(node);
+ } else {
+ /* DAX can replace empty locked entry with a hole */
+ WARN_ON_ONCE(p !=
+ (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
+ RADIX_DAX_ENTRY_LOCK));
+ /* DAX accounts exceptional entries as normal pages */
+ if (node)
+ workingset_node_pages_dec(node);
+ /* Wakeup waiters for exceptional entry lock */
+ dax_wake_mapping_entry_waiter(mapping, page->index,
+ false);
+ }
+ }
+ radix_tree_replace_slot(slot, page);
+ mapping->nrpages++;
+ if (node) {
+ workingset_node_pages_inc(node);
+ /*
+ * Don't track node that contains actual pages.
+ *
+ * Avoid acquiring the list_lru lock if already
+ * untracked. The list_empty() test is safe as
+ * node->private_list is protected by
+ * mapping->tree_lock.
+ */
+ if (!list_empty(&node->private_list))
+ list_lru_del(&workingset_shadow_nodes,
+ &node->private_list);
+ }
+ return 0;
+}
+
static void page_cache_tree_delete(struct address_space *mapping,
struct page *page, void *shadow)
{
- struct radix_tree_node *node;
int i, nr = PageHuge(page) ? 1 : hpage_nr_pages(page);
VM_BUG_ON_PAGE(!PageLocked(page), page);
VM_BUG_ON_PAGE(PageTail(page), page);
VM_BUG_ON_PAGE(nr != 1 && shadow, page);
- if (shadow) {
- mapping->nrexceptional += nr;
- /*
- * Make sure the nrexceptional update is committed before
- * the nrpages update so that final truncate racing
- * with reclaim does not see both counters 0 at the
- * same time and miss a shadow entry.
- */
- smp_wmb();
- }
- mapping->nrpages -= nr;
-
for (i = 0; i < nr; i++) {
- node = radix_tree_replace_clear_tags(&mapping->page_tree,
- page->index + i, shadow);
+ struct radix_tree_node *node;
+ void **slot;
+
+ __radix_tree_lookup(&mapping->page_tree, page->index + i,
+ &node, &slot);
+
+ radix_tree_clear_tags(&mapping->page_tree, node, slot);
+
if (!node) {
VM_BUG_ON_PAGE(nr != 1, page);
- return;
+ /*
+ * We need a node to properly account shadow
+ * entries. Don't plant any without. XXX
+ */
+ shadow = NULL;
}
+ radix_tree_replace_slot(slot, shadow);
+
+ if (!node)
+ break;
+
workingset_node_pages_dec(node);
if (shadow)
workingset_node_shadows_inc(node);
@@ -163,6 +221,18 @@ static void page_cache_tree_delete(struct address_space *mapping,
&node->private_list);
}
}
+
+ if (shadow) {
+ mapping->nrexceptional += nr;
+ /*
+ * Make sure the nrexceptional update is committed before
+ * the nrpages update so that final truncate racing
+ * with reclaim does not see both counters 0 at the
+ * same time and miss a shadow entry.
+ */
+ smp_wmb();
+ }
+ mapping->nrpages -= nr;
}
/*
@@ -561,9 +631,8 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
spin_lock_irqsave(&mapping->tree_lock, flags);
__delete_from_page_cache(old, NULL);
- error = radix_tree_insert(&mapping->page_tree, offset, new);
+ error = page_cache_tree_insert(mapping, new, NULL);
BUG_ON(error);
- mapping->nrpages++;
/*
* hugetlb pages do not participate in page cache accounting.
@@ -584,62 +653,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
}
EXPORT_SYMBOL_GPL(replace_page_cache_page);
-static int page_cache_tree_insert(struct address_space *mapping,
- struct page *page, void **shadowp)
-{
- struct radix_tree_node *node;
- void **slot;
- int error;
-
- error = __radix_tree_create(&mapping->page_tree, page->index, 0,
- &node, &slot);
- if (error)
- return error;
- if (*slot) {
- void *p;
-
- p = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
- if (!radix_tree_exceptional_entry(p))
- return -EEXIST;
-
- mapping->nrexceptional--;
- if (!dax_mapping(mapping)) {
- if (shadowp)
- *shadowp = p;
- if (node)
- workingset_node_shadows_dec(node);
- } else {
- /* DAX can replace empty locked entry with a hole */
- WARN_ON_ONCE(p !=
- (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY |
- RADIX_DAX_ENTRY_LOCK));
- /* DAX accounts exceptional entries as normal pages */
- if (node)
- workingset_node_pages_dec(node);
- /* Wakeup waiters for exceptional entry lock */
- dax_wake_mapping_entry_waiter(mapping, page->index,
- false);
- }
- }
- radix_tree_replace_slot(slot, page);
- mapping->nrpages++;
- if (node) {
- workingset_node_pages_inc(node);
- /*
- * Don't track node that contains actual pages.
- *
- * Avoid acquiring the list_lru lock if already
- * untracked. The list_empty() test is safe as
- * node->private_list is protected by
- * mapping->tree_lock.
- */
- if (!list_empty(&node->private_list))
- list_lru_del(&workingset_shadow_nodes,
- &node->private_list);
- }
- return 0;
-}
-
static int __add_to_page_cache_locked(struct page *page,
struct address_space *mapping,
pgoff_t offset, gfp_t gfp_mask,
@@ -1910,16 +1923,18 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
if (iocb->ki_flags & IOCB_DIRECT) {
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
+ struct iov_iter data = *iter;
loff_t size;
size = i_size_read(inode);
retval = filemap_write_and_wait_range(mapping, iocb->ki_pos,
iocb->ki_pos + count - 1);
- if (!retval) {
- struct iov_iter data = *iter;
- retval = mapping->a_ops->direct_IO(iocb, &data);
- }
+ if (retval < 0)
+ goto out;
+ file_accessed(file);
+
+ retval = mapping->a_ops->direct_IO(iocb, &data);
if (retval > 0) {
iocb->ki_pos += retval;
iov_iter_advance(iter, retval);
@@ -1935,10 +1950,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
* DAX files, so don't bother trying.
*/
if (retval < 0 || !iov_iter_count(iter) || iocb->ki_pos >= size ||
- IS_DAX(inode)) {
- file_accessed(file);
+ IS_DAX(inode))
goto out;
- }
}
retval = do_generic_file_read(file, &iocb->ki_pos, iter, retval);