[PATCH 1/2] btrfs: add helper folio_end()

[David Sterba <dsterba@suse.com>]

There are several cases of folio_pos + folio_size, add a convenience
helper for that. Rename local variable in defrag_prepare_one_folio() to
avoid name clash.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/defrag.c | 8 ++++----
 fs/btrfs/misc.h   | 7 +++++++
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/defrag.c b/fs/btrfs/defrag.c
index 6dca263b224e87..e5739835ad02f0 100644
--- a/fs/btrfs/defrag.c
+++ b/fs/btrfs/defrag.c
@@ -849,7 +849,7 @@ static struct folio *defrag_prepare_one_folio(struct btrfs_inode *inode, pgoff_t
 	struct address_space *mapping = inode->vfs_inode.i_mapping;
 	gfp_t mask = btrfs_alloc_write_mask(mapping);
 	u64 folio_start;
-	u64 folio_end;
+	u64 folio_last;
 	struct extent_state *cached_state = NULL;
 	struct folio *folio;
 	int ret;
@@ -886,14 +886,14 @@ static struct folio *defrag_prepare_one_folio(struct btrfs_inode *inode, pgoff_t
 	}
 
 	folio_start = folio_pos(folio);
-	folio_end = folio_pos(folio) + folio_size(folio) - 1;
+	folio_last = folio_pos(folio) + folio_size(folio) - 1;
 	/* Wait for any existing ordered extent in the range */
 	while (1) {
 		struct btrfs_ordered_extent *ordered;
 
-		btrfs_lock_extent(&inode->io_tree, folio_start, folio_end, &cached_state);
+		btrfs_lock_extent(&inode->io_tree, folio_start, folio_last, &cached_state);
 		ordered = btrfs_lookup_ordered_range(inode, folio_start, folio_size(folio));
-		btrfs_unlock_extent(&inode->io_tree, folio_start, folio_end, &cached_state);
+		btrfs_unlock_extent(&inode->io_tree, folio_start, folio_last, &cached_state);
 		if (!ordered)
 			break;
 
diff --git a/fs/btrfs/misc.h b/fs/btrfs/misc.h
index 9cc292402696cc..ff5eac84d819d8 100644
--- a/fs/btrfs/misc.h
+++ b/fs/btrfs/misc.h
@@ -7,6 +7,8 @@
 #include <linux/bitmap.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
+#include <linux/mm.h>
+#include <linux/pagemap.h>
 #include <linux/math64.h>
 #include <linux/rbtree.h>
 
@@ -158,4 +160,9 @@ static inline bool bitmap_test_range_all_zero(const unsigned long *addr,
 	return (found_set == start + nbits);
 }
 
+static inline u64 folio_end(struct folio *folio)
+{
+	return folio_pos(folio) + folio_size(folio);
+}
+
 #endif
-- 
2.49.0