[PATCH v4 03/10] ceph: add ceph_folio_snap_context()

Add a folio-based counterpart to page_snap_context() that reads the
snap context from folio->private directly.

Convert the three writeback paths that passed &folio->page to
page_snap_context() to ceph_folio_snap_context(), removing three
open-coded folio-to-page conversions. No functional change.

Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Acked-by: Zi Yan <[email protected]>
Signed-off-by: Tal Zussman <[email protected]>
---
 fs/ceph/addr.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index f1f4caa8f9df..60955060dd1b 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -75,6 +75,12 @@ static inline struct ceph_snap_context *page_snap_context(struct page *page)
 	return NULL;
 }
 
+static inline
+struct ceph_snap_context *ceph_folio_snap_context(const struct folio *folio)
+{
+	return folio->private;
+}
+
 /*
  * Dirty a page.  Optimistically adjust accounting, on the assumption
  * that we won't race with invalidate.  If we do, readjust.
@@ -758,7 +764,7 @@ static int write_folio_nounlock(struct folio *folio,
 		return -EIO;
 
 	/* verify this is a writeable snap context */
-	snapc = page_snap_context(&folio->page);
+	snapc = ceph_folio_snap_context(folio);
 	if (!snapc) {
 		doutc(cl, "%llx.%llx folio %p not dirty?\n", ceph_vinop(inode),
 		      folio);
@@ -1183,7 +1189,7 @@ int ceph_check_page_before_write(struct address_space *mapping,
 	}
 
 	/* only if matching snap context */
-	pgsnapc = page_snap_context(&folio->page);
+	pgsnapc = ceph_folio_snap_context(folio);
 	if (pgsnapc != ceph_wbc->snapc) {
 		doutc(cl, "folio snapc %p %lld != oldest %p %lld\n",
 		      pgsnapc, pgsnapc->seq,
@@ -1851,7 +1857,7 @@ ceph_find_incompatible(struct folio *folio)
 
 		folio_wait_writeback(folio);
 
-		snapc = page_snap_context(&folio->page);
+		snapc = ceph_folio_snap_context(folio);
 		if (!snapc || snapc == ci->i_head_snapc)
 			break;
 

-- 
2.39.5