Provide a folio-based replacement for aops->migratepage. Update the
documentation to document migrate_folio instead of migratepage.
Signed-off-by: Matthew Wilcox (Oracle)
---
Documentation/filesystems/locking.rst | 5 ++--
Documentation/filesystems/vfs.rst | 13 ++-
Documentation/vm/page_migration.rst | 33 ++-
include/linux/fs.h| 4 +++-
mm/compaction.c | 4 +++-
mm/migrate.c | 19 ++-
6 files changed, 46 insertions(+), 32 deletions(-)
diff --git a/Documentation/filesystems/locking.rst
b/Documentation/filesystems/locking.rst
index c0fe711f14d3..3d28b23676bd 100644
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -253,7 +253,8 @@ prototypes::
void (*free_folio)(struct folio *);
int (*direct_IO)(struct kiocb *, struct iov_iter *iter);
bool (*isolate_page) (struct page *, isolate_mode_t);
- int (*migratepage)(struct address_space *, struct page *, struct page
*);
+ int (*migrate_folio)(struct address_space *, struct folio *dst,
+ struct folio *src, enum migrate_mode);
void (*putback_page) (struct page *);
int (*launder_folio)(struct folio *);
bool (*is_partially_uptodate)(struct folio *, size_t from, size_t
count);
@@ -281,7 +282,7 @@ release_folio: yes
free_folio:yes
direct_IO:
isolate_page: yes
-migratepage: yes (both)
+migrate_folio: yes (both)
putback_page: yes
launder_folio: yes
is_partially_uptodate: yes
diff --git a/Documentation/filesystems/vfs.rst
b/Documentation/filesystems/vfs.rst
index a08c652467d7..3ae1b039b03f 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -740,7 +740,8 @@ cache in your filesystem. The following members are
defined:
/* isolate a page for migration */
bool (*isolate_page) (struct page *, isolate_mode_t);
/* migrate the contents of a page to the specified target */
- int (*migratepage) (struct page *, struct page *);
+ int (*migrate_folio)(struct mapping *, struct folio *dst,
+ struct folio *src, enum migrate_mode);
/* put migration-failed page back to right list */
void (*putback_page) (struct page *);
int (*launder_folio) (struct folio *);
@@ -935,12 +936,12 @@ cache in your filesystem. The following members are
defined:
is successfully isolated, VM marks the page as PG_isolated via
__SetPageIsolated.
-``migrate_page``
+``migrate_folio``
This is used to compact the physical memory usage. If the VM
- wants to relocate a page (maybe off a memory card that is
- signalling imminent failure) it will pass a new page and an old
- page to this function. migrate_page should transfer any private
- data across and update any references that it has to the page.
+ wants to relocate a folio (maybe from a memory device that is
+ signalling imminent failure) it will pass a new folio and an old
+ folio to this function. migrate_folio should transfer any private
+ data across and update any references that it has to the folio.
``putback_page``
Called by the VM when isolated page's migration fails.
diff --git a/Documentation/vm/page_migration.rst
b/Documentation/vm/page_migration.rst
index 8c5cb8147e55..e0f73ddfabb1 100644
--- a/Documentation/vm/page_migration.rst
+++ b/Documentation/vm/page_migration.rst
@@ -181,22 +181,23 @@ which are function pointers of struct
address_space_operations.
Once page is successfully isolated, VM uses page.lru fields so driver
shouldn't expect to preserve values in those fields.
-2. ``int (*migratepage) (struct address_space *mapping,``
-| ``struct page *newpage, struct page *oldpage, enum migrate_mode);``
-
- After isolation, VM calls migratepage() of driver with the isolated page.
- The function of migratepage() is to move the contents of the old page to the
- new page
- and set up fields of struct page newpage. Keep in mind that you should
- indicate to the VM the oldpage is no longer movable via __ClearPageMovable()
- under page_lock if you migrated the oldpage successfully and returned
- MIGRATEPAGE_SUCCESS. If driver cannot migrate the page at the moment, driver
- can return -EAGAIN. On -EAGAIN, VM will retry page migration in a short time
- because VM interprets -EAGAIN as "temporary migration failure". On returning
- any error except -EAGAIN, VM will give up the page migration without
- retrying.
-
- Driver shouldn't touch the page.lru field while in the migratepage()
function.
+2. ``int (*migrate_folio) (struct address_space *mapping,``
+| ``struct folio *dst, struct folio *src, enum migrate_mode);``
+
+
