Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8543b1a..fcb3f04 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -29,12 +29,13 @@
 	AS_EXITING	= 4, 	/* final truncate in progress */
 	/* writeback related tags are not used */
 	AS_NO_WRITEBACK_TAGS = 5,
+	AS_THP_SUPPORT = 6,	/* THPs supported */
 };
 
 /**
  * mapping_set_error - record a writeback error in the address_space
- * @mapping - the mapping in which an error should be set
- * @error - the error to set in the mapping
+ * @mapping: the mapping in which an error should be set
+ * @error: the error to set in the mapping
  *
  * When writeback fails in some way, we must record that error so that
  * userspace can be informed when fsync and the like are called.  We endeavor
@@ -51,7 +52,11 @@
 		return;
 
 	/* Record in wb_err for checkers using errseq_t based tracking */
-	filemap_set_wb_err(mapping, error);
+	__filemap_set_wb_err(mapping, error);
+
+	/* Record it in superblock */
+	if (mapping->host)
+		errseq_set(&mapping->host->i_sb->s_wb_err, error);
 
 	/* Record it in flags for now, for legacy callers */
 	if (error == -ENOSPC)
@@ -70,11 +75,9 @@
 	clear_bit(AS_UNEVICTABLE, &mapping->flags);
 }
 
-static inline int mapping_unevictable(struct address_space *mapping)
+static inline bool mapping_unevictable(struct address_space *mapping)
 {
-	if (mapping)
-		return test_bit(AS_UNEVICTABLE, &mapping->flags);
-	return !!mapping;
+	return mapping && test_bit(AS_UNEVICTABLE, &mapping->flags);
 }
 
 static inline void mapping_set_exiting(struct address_space *mapping)
@@ -118,6 +121,40 @@
 	m->gfp_mask = mask;
 }
 
+static inline bool mapping_thp_support(struct address_space *mapping)
+{
+	return test_bit(AS_THP_SUPPORT, &mapping->flags);
+}
+
+static inline int filemap_nr_thps(struct address_space *mapping)
+{
+#ifdef CONFIG_READ_ONLY_THP_FOR_FS
+	return atomic_read(&mapping->nr_thps);
+#else
+	return 0;
+#endif
+}
+
+static inline void filemap_nr_thps_inc(struct address_space *mapping)
+{
+#ifdef CONFIG_READ_ONLY_THP_FOR_FS
+	if (!mapping_thp_support(mapping))
+		atomic_inc(&mapping->nr_thps);
+#else
+	WARN_ON_ONCE(1);
+#endif
+}
+
+static inline void filemap_nr_thps_dec(struct address_space *mapping)
+{
+#ifdef CONFIG_READ_ONLY_THP_FOR_FS
+	if (!mapping_thp_support(mapping))
+		atomic_dec(&mapping->nr_thps);
+#else
+	WARN_ON_ONCE(1);
+#endif
+}
+
 void release_pages(struct page **pages, int nr);
 
 /*
@@ -207,6 +244,43 @@
 	return __page_cache_add_speculative(page, count);
 }
 
+/**
+ * attach_page_private - Attach private data to a page.
+ * @page: Page to attach data to.
+ * @data: Data to attach to page.
+ *
+ * Attaching private data to a page increments the page's reference count.
+ * The data must be detached before the page will be freed.
+ */
+static inline void attach_page_private(struct page *page, void *data)
+{
+	get_page(page);
+	set_page_private(page, (unsigned long)data);
+	SetPagePrivate(page);
+}
+
+/**
+ * detach_page_private - Detach private data from a page.
+ * @page: Page to detach data from.
+ *
+ * Removes the data that was previously attached to the page and decrements
+ * the refcount on the page.
+ *
+ * Return: Data that was attached to the page.
+ */
+static inline void *detach_page_private(struct page *page)
+{
+	void *data = (void *)page_private(page);
+
+	if (!PagePrivate(page))
+		return NULL;
+	ClearPagePrivate(page);
+	set_page_private(page, 0);
+	put_page(page);
+
+	return data;
+}
+
 #ifdef CONFIG_NUMA
 extern struct page *__page_cache_alloc(gfp_t gfp);
 #else
@@ -240,6 +314,7 @@
 #define FGP_NOFS		0x00000010
 #define FGP_NOWAIT		0x00000020
 #define FGP_FOR_MMAP		0x00000040
+#define FGP_HEAD		0x00000080
 
 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
 		int fgp_flags, gfp_t cache_gfp_mask);
@@ -269,20 +344,39 @@
 /**
  * find_lock_page - locate, pin and lock a pagecache page
  * @mapping: the address_space to search
- * @offset: the page index
+ * @index: the page index
  *
- * Looks up the page cache slot at @mapping & @offset.  If there is a
+ * Looks up the page cache entry at @mapping & @index.  If there is a
  * page cache page, it is returned locked and with an increased
  * refcount.
  *
- * Otherwise, %NULL is returned.
- *
- * find_lock_page() may sleep.
+ * Context: May sleep.
+ * Return: A struct page or %NULL if there is no page in the cache for this
+ * index.
  */
 static inline struct page *find_lock_page(struct address_space *mapping,
-					pgoff_t offset)
+					pgoff_t index)
 {
-	return pagecache_get_page(mapping, offset, FGP_LOCK, 0);
+	return pagecache_get_page(mapping, index, FGP_LOCK, 0);
+}
+
+/**
+ * find_lock_head - Locate, pin and lock a pagecache page.
+ * @mapping: The address_space to search.
+ * @index: The page index.
+ *
+ * Looks up the page cache entry at @mapping & @index.  If there is a
+ * page cache page, its head page is returned locked and with an increased
+ * refcount.
+ *
+ * Context: May sleep.
+ * Return: A struct page which is !PageTail, or %NULL if there is no page
+ * in the cache for this index.
+ */
+static inline struct page *find_lock_head(struct address_space *mapping,
+					pgoff_t index)
+{
+	return pagecache_get_page(mapping, index, FGP_LOCK | FGP_HEAD, 0);
 }
 
 /**
@@ -305,9 +399,9 @@
  * atomic allocation!
  */
 static inline struct page *find_or_create_page(struct address_space *mapping,
-					pgoff_t offset, gfp_t gfp_mask)
+					pgoff_t index, gfp_t gfp_mask)
 {
-	return pagecache_get_page(mapping, offset,
+	return pagecache_get_page(mapping, index,
 					FGP_LOCK|FGP_ACCESSED|FGP_CREAT,
 					gfp_mask);
 }
@@ -333,18 +427,28 @@
 			mapping_gfp_mask(mapping));
 }
 
-static inline struct page *find_subpage(struct page *page, pgoff_t offset)
+/* Does this page contain this index? */
+static inline bool thp_contains(struct page *head, pgoff_t index)
 {
-	if (PageHuge(page))
-		return page;
-
-	VM_BUG_ON_PAGE(PageTail(page), page);
-
-	return page + (offset & (compound_nr(page) - 1));
+	/* HugeTLBfs indexes the page cache in units of hpage_size */
+	if (PageHuge(head))
+		return head->index == index;
+	return page_index(head) == (index & ~(thp_nr_pages(head) - 1UL));
 }
 
-struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
-struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
+/*
+ * Given the page we found in the page cache, return the page corresponding
+ * to this index in the file
+ */
+static inline struct page *find_subpage(struct page *head, pgoff_t index)
+{
+	/* HugeTLBfs wants the head page regardless */
+	if (PageHuge(head))
+		return head;
+
+	return head + (index & (thp_nr_pages(head) - 1));
+}
+
 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
 			  unsigned int nr_entries, struct page **entries,
 			  pgoff_t *indices);
@@ -456,8 +560,34 @@
 	return pgoff;
 }
 
+struct wait_page_key {
+	struct page *page;
+	int bit_nr;
+	int page_match;
+};
+
+struct wait_page_queue {
+	struct page *page;
+	int bit_nr;
+	wait_queue_entry_t wait;
+};
+
+static inline bool wake_page_match(struct wait_page_queue *wait_page,
+				  struct wait_page_key *key)
+{
+	if (wait_page->page != key->page)
+	       return false;
+	key->page_match = 1;
+
+	if (wait_page->bit_nr != key->bit_nr)
+		return false;
+
+	return true;
+}
+
 extern void __lock_page(struct page *page);
 extern int __lock_page_killable(struct page *page);
+extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);
 extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 				unsigned int flags);
 extern void unlock_page(struct page *page);
@@ -495,10 +625,26 @@
 }
 
 /*
+ * lock_page_async - Lock the page, unless this would block. If the page
+ * is already locked, then queue a callback when the page becomes unlocked.
+ * This callback can then retry the operation.
+ *
+ * Returns 0 if the page is locked successfully, or -EIOCBQUEUED if the page
+ * was already locked and the callback defined in 'wait' was queued.
+ */
+static inline int lock_page_async(struct page *page,
+				  struct wait_page_queue *wait)
+{
+	if (!trylock_page(page))
+		return __lock_page_async(page, wait);
+	return 0;
+}
+
+/*
  * lock_page_or_retry - Lock the page, unless this would block and the
  * caller indicated that it can handle a retry.
  *
- * Return value and mmap_sem implications depend on flags; see
+ * Return value and mmap_lock implications depend on flags; see
  * __lock_page_or_retry().
  */
 static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
@@ -631,10 +777,257 @@
 	return error;
 }
 
+/**
+ * struct readahead_control - Describes a readahead request.
+ *
+ * A readahead request is for consecutive pages.  Filesystems which
+ * implement the ->readahead method should call readahead_page() or
+ * readahead_page_batch() in a loop and attempt to start I/O against
+ * each page in the request.
+ *
+ * Most of the fields in this struct are private and should be accessed
+ * by the functions below.
+ *
+ * @file: The file, used primarily by network filesystems for authentication.
+ *	  May be NULL if invoked internally by the filesystem.
+ * @mapping: Readahead this filesystem object.
+ */
+struct readahead_control {
+	struct file *file;
+	struct address_space *mapping;
+/* private: use the readahead_* accessors instead */
+	pgoff_t _index;
+	unsigned int _nr_pages;
+	unsigned int _batch_count;
+};
+
+#define DEFINE_READAHEAD(rac, f, m, i)					\
+	struct readahead_control rac = {				\
+		.file = f,						\
+		.mapping = m,						\
+		._index = i,						\
+	}
+
+#define VM_READAHEAD_PAGES	(SZ_128K / PAGE_SIZE)
+
+void page_cache_ra_unbounded(struct readahead_control *,
+		unsigned long nr_to_read, unsigned long lookahead_count);
+void page_cache_sync_ra(struct readahead_control *, struct file_ra_state *,
+		unsigned long req_count);
+void page_cache_async_ra(struct readahead_control *, struct file_ra_state *,
+		struct page *, unsigned long req_count);
+
+/**
+ * page_cache_sync_readahead - generic file readahead
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @file: Used by the filesystem for authentication.
+ * @index: Index of first page to be read.
+ * @req_count: Total number of pages being read by the caller.
+ *
+ * page_cache_sync_readahead() should be called when a cache miss happened:
+ * it will submit the read.  The readahead logic may decide to piggyback more
+ * pages onto the read request if access patterns suggest it will improve
+ * performance.
+ */
+static inline
+void page_cache_sync_readahead(struct address_space *mapping,
+		struct file_ra_state *ra, struct file *file, pgoff_t index,
+		unsigned long req_count)
+{
+	DEFINE_READAHEAD(ractl, file, mapping, index);
+	page_cache_sync_ra(&ractl, ra, req_count);
+}
+
+/**
+ * page_cache_async_readahead - file readahead for marked pages
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @file: Used by the filesystem for authentication.
+ * @page: The page at @index which triggered the readahead call.
+ * @index: Index of first page to be read.
+ * @req_count: Total number of pages being read by the caller.
+ *
+ * page_cache_async_readahead() should be called when a page is used which
+ * is marked as PageReadahead; this is a marker to suggest that the application
+ * has used up enough of the readahead window that we should start pulling in
+ * more pages.
+ */
+static inline
+void page_cache_async_readahead(struct address_space *mapping,
+		struct file_ra_state *ra, struct file *file,
+		struct page *page, pgoff_t index, unsigned long req_count)
+{
+	DEFINE_READAHEAD(ractl, file, mapping, index);
+	page_cache_async_ra(&ractl, ra, page, req_count);
+}
+
+/**
+ * readahead_page - Get the next page to read.
+ * @rac: The current readahead request.
+ *
+ * Context: The page is locked and has an elevated refcount.  The caller
+ * should decreases the refcount once the page has been submitted for I/O
+ * and unlock the page once all I/O to that page has completed.
+ * Return: A pointer to the next page, or %NULL if we are done.
+ */
+static inline struct page *readahead_page(struct readahead_control *rac)
+{
+	struct page *page;
+
+	BUG_ON(rac->_batch_count > rac->_nr_pages);
+	rac->_nr_pages -= rac->_batch_count;
+	rac->_index += rac->_batch_count;
+
+	if (!rac->_nr_pages) {
+		rac->_batch_count = 0;
+		return NULL;
+	}
+
+	page = xa_load(&rac->mapping->i_pages, rac->_index);
+	VM_BUG_ON_PAGE(!PageLocked(page), page);
+	rac->_batch_count = thp_nr_pages(page);
+
+	return page;
+}
+
+static inline unsigned int __readahead_batch(struct readahead_control *rac,
+		struct page **array, unsigned int array_sz)
+{
+	unsigned int i = 0;
+	XA_STATE(xas, &rac->mapping->i_pages, 0);
+	struct page *page;
+
+	BUG_ON(rac->_batch_count > rac->_nr_pages);
+	rac->_nr_pages -= rac->_batch_count;
+	rac->_index += rac->_batch_count;
+	rac->_batch_count = 0;
+
+	xas_set(&xas, rac->_index);
+	rcu_read_lock();
+	xas_for_each(&xas, page, rac->_index + rac->_nr_pages - 1) {
+		if (xas_retry(&xas, page))
+			continue;
+		VM_BUG_ON_PAGE(!PageLocked(page), page);
+		VM_BUG_ON_PAGE(PageTail(page), page);
+		array[i++] = page;
+		rac->_batch_count += thp_nr_pages(page);
+
+		/*
+		 * The page cache isn't using multi-index entries yet,
+		 * so the xas cursor needs to be manually moved to the
+		 * next index.  This can be removed once the page cache
+		 * is converted.
+		 */
+		if (PageHead(page))
+			xas_set(&xas, rac->_index + rac->_batch_count);
+
+		if (i == array_sz)
+			break;
+	}
+	rcu_read_unlock();
+
+	return i;
+}
+
+/**
+ * readahead_page_batch - Get a batch of pages to read.
+ * @rac: The current readahead request.
+ * @array: An array of pointers to struct page.
+ *
+ * Context: The pages are locked and have an elevated refcount.  The caller
+ * should decreases the refcount once the page has been submitted for I/O
+ * and unlock the page once all I/O to that page has completed.
+ * Return: The number of pages placed in the array.  0 indicates the request
+ * is complete.
+ */
+#define readahead_page_batch(rac, array)				\
+	__readahead_batch(rac, array, ARRAY_SIZE(array))
+
+/**
+ * readahead_pos - The byte offset into the file of this readahead request.
+ * @rac: The readahead request.
+ */
+static inline loff_t readahead_pos(struct readahead_control *rac)
+{
+	return (loff_t)rac->_index * PAGE_SIZE;
+}
+
+/**
+ * readahead_length - The number of bytes in this readahead request.
+ * @rac: The readahead request.
+ */
+static inline loff_t readahead_length(struct readahead_control *rac)
+{
+	return (loff_t)rac->_nr_pages * PAGE_SIZE;
+}
+
+/**
+ * readahead_index - The index of the first page in this readahead request.
+ * @rac: The readahead request.
+ */
+static inline pgoff_t readahead_index(struct readahead_control *rac)
+{
+	return rac->_index;
+}
+
+/**
+ * readahead_count - The number of pages in this readahead request.
+ * @rac: The readahead request.
+ */
+static inline unsigned int readahead_count(struct readahead_control *rac)
+{
+	return rac->_nr_pages;
+}
+
 static inline unsigned long dir_pages(struct inode *inode)
 {
 	return (unsigned long)(inode->i_size + PAGE_SIZE - 1) >>
 			       PAGE_SHIFT;
 }
 
+/**
+ * page_mkwrite_check_truncate - check if page was truncated
+ * @page: the page to check
+ * @inode: the inode to check the page against
+ *
+ * Returns the number of bytes in the page up to EOF,
+ * or -EFAULT if the page was truncated.
+ */
+static inline int page_mkwrite_check_truncate(struct page *page,
+					      struct inode *inode)
+{
+	loff_t size = i_size_read(inode);
+	pgoff_t index = size >> PAGE_SHIFT;
+	int offset = offset_in_page(size);
+
+	if (page->mapping != inode->i_mapping)
+		return -EFAULT;
+
+	/* page is wholly inside EOF */
+	if (page->index < index)
+		return PAGE_SIZE;
+	/* page is wholly past EOF */
+	if (page->index > index || !offset)
+		return -EFAULT;
+	/* page is partially inside EOF */
+	return offset;
+}
+
+/**
+ * i_blocks_per_page - How many blocks fit in this page.
+ * @inode: The inode which contains the blocks.
+ * @page: The page (head page if the page is a THP).
+ *
+ * If the block size is larger than the size of this page, return zero.
+ *
+ * Context: The caller should hold a refcount on the page to prevent it
+ * from being split.
+ * Return: The number of filesystem blocks covered by this page.
+ */
+static inline
+unsigned int i_blocks_per_page(struct inode *inode, struct page *page)
+{
+	return thp_size(page) >> inode->i_blkbits;
+}
 #endif /* _LINUX_PAGEMAP_H */