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authorMatthew Wilcox (Oracle) <willy@infradead.org>2022-06-06 10:20:31 -0400
committerMatthew Wilcox (Oracle) <willy@infradead.org>2022-08-02 12:34:03 -0400
commit67235182a41c1bd6b32806a1556a1d299b84212b (patch)
treeb57dbdb55adf121d6d7450446b3762551c7548f4 /mm
parent2be7fa10c028019f7b2fee11238987762567d41e (diff)
mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
Use a folio throughout __buffer_migrate_folio(), add kernel-doc for buffer_migrate_folio() and buffer_migrate_folio_norefs(), move their declarations to buffer.h and switch all filesystems that have wired them up. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'mm')
-rw-r--r--mm/migrate.c76
1 files changed, 46 insertions, 30 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 75b171425c45..ea5398d0f7f1 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -656,23 +656,23 @@ static bool buffer_migrate_lock_buffers(struct buffer_head *head,
return true;
}
-static int __buffer_migrate_page(struct address_space *mapping,
- struct page *newpage, struct page *page, enum migrate_mode mode,
+static int __buffer_migrate_folio(struct address_space *mapping,
+ struct folio *dst, struct folio *src, enum migrate_mode mode,
bool check_refs)
{
struct buffer_head *bh, *head;
int rc;
int expected_count;
- if (!page_has_buffers(page))
- return migrate_page(mapping, newpage, page, mode);
+ head = folio_buffers(src);
+ if (!head)
+ return migrate_page(mapping, &dst->page, &src->page, mode);
/* Check whether page does not have extra refs before we do more work */
- expected_count = expected_page_refs(mapping, page);
- if (page_count(page) != expected_count)
+ expected_count = expected_page_refs(mapping, &src->page);
+ if (folio_ref_count(src) != expected_count)
return -EAGAIN;
- head = page_buffers(page);
if (!buffer_migrate_lock_buffers(head, mode))
return -EAGAIN;
@@ -703,23 +703,22 @@ recheck_buffers:
}
}
- rc = migrate_page_move_mapping(mapping, newpage, page, 0);
+ rc = folio_migrate_mapping(mapping, dst, src, 0);
if (rc != MIGRATEPAGE_SUCCESS)
goto unlock_buffers;
- attach_page_private(newpage, detach_page_private(page));
+ folio_attach_private(dst, folio_detach_private(src));
bh = head;
do {
- set_bh_page(bh, newpage, bh_offset(bh));
+ set_bh_page(bh, &dst->page, bh_offset(bh));
bh = bh->b_this_page;
-
} while (bh != head);
if (mode != MIGRATE_SYNC_NO_COPY)
- migrate_page_copy(newpage, page);
+ folio_migrate_copy(dst, src);
else
- migrate_page_states(newpage, page);
+ folio_migrate_flags(dst, src);
rc = MIGRATEPAGE_SUCCESS;
unlock_buffers:
@@ -729,34 +728,51 @@ unlock_buffers:
do {
unlock_buffer(bh);
bh = bh->b_this_page;
-
} while (bh != head);
return rc;
}
-/*
- * Migration function for pages with buffers. This function can only be used
- * if the underlying filesystem guarantees that no other references to "page"
- * exist. For example attached buffer heads are accessed only under page lock.
+/**
+ * buffer_migrate_folio() - Migration function for folios with buffers.
+ * @mapping: The address space containing @src.
+ * @dst: The folio to migrate to.
+ * @src: The folio to migrate from.
+ * @mode: How to migrate the folio.
+ *
+ * This function can only be used if the underlying filesystem guarantees
+ * that no other references to @src exist. For example attached buffer
+ * heads are accessed only under the folio lock. If your filesystem cannot
+ * provide this guarantee, buffer_migrate_folio_norefs() may be more
+ * appropriate.
+ *
+ * Return: 0 on success or a negative errno on failure.
*/
-int buffer_migrate_page(struct address_space *mapping,
- struct page *newpage, struct page *page, enum migrate_mode mode)
+int buffer_migrate_folio(struct address_space *mapping,
+ struct folio *dst, struct folio *src, enum migrate_mode mode)
{
- return __buffer_migrate_page(mapping, newpage, page, mode, false);
+ return __buffer_migrate_folio(mapping, dst, src, mode, false);
}
-EXPORT_SYMBOL(buffer_migrate_page);
+EXPORT_SYMBOL(buffer_migrate_folio);
-/*
- * Same as above except that this variant is more careful and checks that there
- * are also no buffer head references. This function is the right one for
- * mappings where buffer heads are directly looked up and referenced (such as
- * block device mappings).
+/**
+ * buffer_migrate_folio_norefs() - Migration function for folios with buffers.
+ * @mapping: The address space containing @src.
+ * @dst: The folio to migrate to.
+ * @src: The folio to migrate from.
+ * @mode: How to migrate the folio.
+ *
+ * Like buffer_migrate_folio() except that this variant is more careful
+ * and checks that there are also no buffer head references. This function
+ * is the right one for mappings where buffer heads are directly looked
+ * up and referenced (such as block device mappings).
+ *
+ * Return: 0 on success or a negative errno on failure.
*/
-int buffer_migrate_page_norefs(struct address_space *mapping,
- struct page *newpage, struct page *page, enum migrate_mode mode)
+int buffer_migrate_folio_norefs(struct address_space *mapping,
+ struct folio *dst, struct folio *src, enum migrate_mode mode)
{
- return __buffer_migrate_page(mapping, newpage, page, mode, true);
+ return __buffer_migrate_folio(mapping, dst, src, mode, true);
}
#endif