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From:   "Matthew Wilcox (Oracle)" <willy@infradead.org>
To:     linux-mm@kvack.org
Cc:     "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Hugh Dickins <hughd@google.com>,
        William Kucharski <william.kucharski@oracle.com>,
        Johannes Weiner <hannes@cmpxchg.org>, Jan Kara <jack@suse.cz>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 6/7] mm: Pass pvec directly to find_get_entries
Date:   Wed, 19 Aug 2020 16:05:54 +0100
Message-Id: <20200819150555.31669-7-willy@infradead.org>
In-Reply-To: <20200819150555.31669-1-willy@infradead.org>
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All callers of find_get_entries() use a pvec, so pass it directly
instead of manipulating it in the caller.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/pagemap.h |  3 +--
 mm/filemap.c            | 14 ++++++--------
 mm/shmem.c              | 11 +++--------
 mm/swap.c               |  4 +---
 4 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 3f0dc8d00f2a..9d465dd8b379 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -387,8 +387,7 @@ static inline struct page *find_subpage(struct page *head, pgoff_t index)
 struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
 struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset);
 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
-		pgoff_t end, unsigned int nr_entries, struct page **entries,
-		pgoff_t *indices);
+		pgoff_t end, struct pagevec *pvec, pgoff_t *indices);
 unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
 			pgoff_t end, unsigned int nr_pages,
 			struct page **pages);
diff --git a/mm/filemap.c b/mm/filemap.c
index 159cf3d6f1ae..892c7beef392 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1743,8 +1743,7 @@ EXPORT_SYMBOL(pagecache_get_page);
  * @mapping:	The address_space to search
  * @start:	The starting page cache index
  * @end:	The highest page cache index to return.
- * @nr_entries:	The maximum number of entries
- * @entries:	Where the resulting entries are placed
+ * @pvec:	Where the resulting entries are placed
  * @indices:	The cache indices corresponding to the entries in @entries
  *
  * find_get_entries() will search for and return a group of up to
@@ -1767,15 +1766,12 @@ EXPORT_SYMBOL(pagecache_get_page);
  * Return: the number of pages and shadow entries which were found.
  */
 unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
-		pgoff_t end, unsigned int nr_entries, struct page **entries,
-		pgoff_t *indices)
+		pgoff_t end, struct pagevec *pvec, pgoff_t *indices)
 {
 	XA_STATE(xas, &mapping->i_pages, start);
 	struct page *page;
 	unsigned int ret = 0;
-
-	if (!nr_entries)
-		return 0;
+	unsigned nr_entries = PAGEVEC_SIZE;
 
 	rcu_read_lock();
 	xas_for_each(&xas, page, end) {
@@ -1806,7 +1802,7 @@ unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
 		}
 export:
 		indices[ret] = xas.xa_index;
-		entries[ret] = page;
+		pvec->pages[ret] = page;
 		if (++ret == nr_entries)
 			break;
 		continue;
@@ -1816,6 +1812,8 @@ unsigned find_get_entries(struct address_space *mapping, pgoff_t start,
 		xas_reset(&xas);
 	}
 	rcu_read_unlock();
+
+	pvec->nr = ret;
 	return ret;
 }
 
diff --git a/mm/shmem.c b/mm/shmem.c
index abdbe61a1aa7..e73c0b2ba99c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -905,11 +905,7 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 
 	pagevec_init(&pvec);
 	index = start;
-	while (index < end) {
-		pvec.nr = find_get_entries(mapping, index, end - 1,
-				PAGEVEC_SIZE, pvec.pages, indices);
-		if (!pvec.nr)
-			break;
+	while (find_get_entries(mapping, index, end - 1, &pvec, indices)) {
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
 
@@ -976,9 +972,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend,
 	while (index < end) {
 		cond_resched();
 
-		pvec.nr = find_get_entries(mapping, index, end - 1,
-				PAGEVEC_SIZE, pvec.pages, indices);
-		if (!pvec.nr) {
+		if (!find_get_entries(mapping, index, end - 1, &pvec,
+				indices)) {
 			/* If all gone or hole-punch or unfalloc, we're done */
 			if (index == start || end != -1)
 				break;
diff --git a/mm/swap.c b/mm/swap.c
index d4e3ba4c967c..40b23300d353 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -1060,9 +1060,7 @@ unsigned pagevec_lookup_entries(struct pagevec *pvec,
 		struct address_space *mapping, pgoff_t start, pgoff_t end,
 		pgoff_t *indices)
 {
-	pvec->nr = find_get_entries(mapping, start, end, PAGEVEC_SIZE,
-				    pvec->pages, indices);
-	return pagevec_count(pvec);
+	return find_get_entries(mapping, start, end, pvec, indices);
 }
 
 /**
-- 
2.28.0