[PATCH 3/6] ceph: use a folio in the READ_INLINE path of ceph_read_iter()

[Tal Zussman]

The inline data is read into a scratch buffer that never enters the page
cache, so allocate it with folio_alloc() instead of
__page_cache_alloc(). This drops the cpuset page spreading that
__page_cache_alloc() applies on NUMA systems, which only makes sense for
page cache pages. The temporary buffer here is better off node local.

The mismatched __free_page()/__free_pages() pair both become
folio_put(). The __ceph_do_getattr() locked page plumbing will be
converted in a later patch, so pass &folio->page for now.

Signed-off-by: Tal Zussman <tz2294@xxxxxxxxxxxx>
---
 fs/ceph/file.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index f322ba42102d..592e32d1e2d4 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -2264,21 +2264,22 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
 
 	if (retry_op > HAVE_RETRIED && ret >= 0) {
 		int statret;
-		struct page *page = NULL;
+		struct folio *folio = NULL;
 		loff_t i_size;
 		int mask = CEPH_STAT_CAP_SIZE;
 		if (retry_op == READ_INLINE) {
-			page = __page_cache_alloc(GFP_KERNEL);
-			if (!page)
+			folio = folio_alloc(GFP_KERNEL, 0);
+			if (!folio)
 				return -ENOMEM;
 
 			mask = CEPH_STAT_CAP_INLINE_DATA;
 		}
 
-		statret = __ceph_do_getattr(inode, page, mask, !!page);
+		statret = __ceph_do_getattr(inode, folio ? &folio->page : NULL,
+					    mask, !!folio);
 		if (statret < 0) {
-			if (page)
-				__free_page(page);
+			if (folio)
+				folio_put(folio);
 			if (statret == -ENODATA) {
 				BUG_ON(retry_op != READ_INLINE);
 				goto again;
@@ -2295,8 +2296,8 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
 						   iocb->ki_pos + len);
 				end = min_t(loff_t, end, PAGE_SIZE);
 				if (statret < end)
-					zero_user_segment(page, statret, end);
-				ret = copy_page_to_iter(page,
+					folio_zero_segment(folio, statret, end);
+				ret = copy_folio_to_iter(folio,
 						iocb->ki_pos & ~PAGE_MASK,
 						end - iocb->ki_pos, to);
 				iocb->ki_pos += ret;
@@ -2309,7 +2310,7 @@ static ssize_t ceph_read_iter(struct kiocb *iocb, struct iov_iter *to)
 				iocb->ki_pos += ret;
 				read += ret;
 			}
-			__free_pages(page, 0);
+			folio_put(folio);
 			return read;
 		}
 

-- 
2.39.5