The patch titled
Subject: mm: migrate: move migrate_page_lock_buffers()
has been added to the -mm tree. Its filename is
mm-migrate-move-migrate_page_lock_buffers.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-migrate-move-migrate_page_lock_buffers.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-migrate-move-migrate_page_lock_buffers.patch
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------------------------------------------------------
From: Jan Kara <jack@xxxxxxx>
Subject: mm: migrate: move migrate_page_lock_buffers()
buffer_migrate_page() is the only caller of migrate_page_lock_buffers()
move it close to it and also drop the now unused stub for !CONFIG_BLOCK.
Link: http://lkml.kernel.org/r/20181211172143.7358-4-jack@xxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/mm/migrate.c~mm-migrate-move-migrate_page_lock_buffers
+++ a/mm/migrate.c
@@ -374,56 +374,6 @@ unlock:
}
#endif
-#ifdef CONFIG_BLOCK
-/* Returns true if all buffers are successfully locked */
-static bool buffer_migrate_lock_buffers(struct buffer_head *head,
- enum migrate_mode mode)
-{
- struct buffer_head *bh = head;
-
- /* Simple case, sync compaction */
- if (mode != MIGRATE_ASYNC) {
- do {
- get_bh(bh);
- lock_buffer(bh);
- bh = bh->b_this_page;
-
- } while (bh != head);
-
- return true;
- }
-
- /* async case, we cannot block on lock_buffer so use trylock_buffer */
- do {
- get_bh(bh);
- if (!trylock_buffer(bh)) {
- /*
- * We failed to lock the buffer and cannot stall in
- * async migration. Release the taken locks
- */
- struct buffer_head *failed_bh = bh;
- put_bh(failed_bh);
- bh = head;
- while (bh != failed_bh) {
- unlock_buffer(bh);
- put_bh(bh);
- bh = bh->b_this_page;
- }
- return false;
- }
-
- bh = bh->b_this_page;
- } while (bh != head);
- return true;
-}
-#else
-static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,
- enum migrate_mode mode)
-{
- return true;
-}
-#endif /* CONFIG_BLOCK */
-
static int expected_page_refs(struct page *page)
{
int expected_count = 1;
@@ -751,6 +701,48 @@ int migrate_page(struct address_space *m
EXPORT_SYMBOL(migrate_page);
#ifdef CONFIG_BLOCK
+/* Returns true if all buffers are successfully locked */
+static bool buffer_migrate_lock_buffers(struct buffer_head *head,
+ enum migrate_mode mode)
+{
+ struct buffer_head *bh = head;
+
+ /* Simple case, sync compaction */
+ if (mode != MIGRATE_ASYNC) {
+ do {
+ get_bh(bh);
+ lock_buffer(bh);
+ bh = bh->b_this_page;
+
+ } while (bh != head);
+
+ return true;
+ }
+
+ /* async case, we cannot block on lock_buffer so use trylock_buffer */
+ do {
+ get_bh(bh);
+ if (!trylock_buffer(bh)) {
+ /*
+ * We failed to lock the buffer and cannot stall in
+ * async migration. Release the taken locks
+ */
+ struct buffer_head *failed_bh = bh;
+ put_bh(failed_bh);
+ bh = head;
+ while (bh != failed_bh) {
+ unlock_buffer(bh);
+ put_bh(bh);
+ bh = bh->b_this_page;
+ }
+ return false;
+ }
+
+ bh = bh->b_this_page;
+ } while (bh != head);
+ return true;
+}
+
/*
* Migration function for pages with buffers. This function can only be used
* if the underlying filesystem guarantees that no other references to "page"
_
Patches currently in -mm which might be from jack@xxxxxxx are
mm-migration-factor-out-code-to-compute-expected-number-of-page-references.patch
mm-migrate-lock-buffers-before-migrate_page_move_mapping.patch
mm-migrate-move-migrate_page_lock_buffers.patch
mm-migrate-provide-buffer_migrate_page_norefs.patch
blkdev-avoid-migration-stalls-for-blkdev-pages.patch
mm-migrate-drop-unused-argument-of-migrate_page_move_mapping.patch
