The quilt patch titled
Subject: mm: convert DAX lock/unlock page to lock/unlock folio
has been removed from the -mm tree. Its filename was
mm-convert-dax-lock-unlock-page-to-lock-unlock-folio.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: convert DAX lock/unlock page to lock/unlock folio
Date: Wed, 23 Aug 2023 00:13:14 +0100
The one caller of DAX lock/unlock page already calls compound_head(), so
use page_folio() instead, then use a folio throughout the DAX code to
remove uses of page->mapping and page->index.
[jane.chu@xxxxxxxxxx: add comment to mf_generic_kill_procss(), simplify mf_generic_kill_procs:folio initialization]
Link: https://lkml.kernel.org/r/20230908222336.186313-1-jane.chu@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230822231314.349200-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Jane Chu <jane.chu@xxxxxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dax.c | 24 ++++++++++++------------
include/linux/dax.h | 10 +++++-----
mm/memory-failure.c | 29 ++++++++++++++++-------------
3 files changed, 33 insertions(+), 30 deletions(-)
--- a/fs/dax.c~mm-convert-dax-lock-unlock-page-to-lock-unlock-folio
+++ a/fs/dax.c
@@ -412,23 +412,23 @@ static struct page *dax_busy_page(void *
return NULL;
}
-/*
- * dax_lock_page - Lock the DAX entry corresponding to a page
- * @page: The page whose entry we want to lock
+/**
+ * dax_lock_folio - Lock the DAX entry corresponding to a folio
+ * @folio: The folio whose entry we want to lock
*
* Context: Process context.
- * Return: A cookie to pass to dax_unlock_page() or 0 if the entry could
+ * Return: A cookie to pass to dax_unlock_folio() or 0 if the entry could
* not be locked.
*/
-dax_entry_t dax_lock_page(struct page *page)
+dax_entry_t dax_lock_folio(struct folio *folio)
{
XA_STATE(xas, NULL, 0);
void *entry;
- /* Ensure page->mapping isn't freed while we look at it */
+ /* Ensure folio->mapping isn't freed while we look at it */
rcu_read_lock();
for (;;) {
- struct address_space *mapping = READ_ONCE(page->mapping);
+ struct address_space *mapping = READ_ONCE(folio->mapping);
entry = NULL;
if (!mapping || !dax_mapping(mapping))
@@ -447,11 +447,11 @@ dax_entry_t dax_lock_page(struct page *p
xas.xa = &mapping->i_pages;
xas_lock_irq(&xas);
- if (mapping != page->mapping) {
+ if (mapping != folio->mapping) {
xas_unlock_irq(&xas);
continue;
}
- xas_set(&xas, page->index);
+ xas_set(&xas, folio->index);
entry = xas_load(&xas);
if (dax_is_locked(entry)) {
rcu_read_unlock();
@@ -467,10 +467,10 @@ dax_entry_t dax_lock_page(struct page *p
return (dax_entry_t)entry;
}
-void dax_unlock_page(struct page *page, dax_entry_t cookie)
+void dax_unlock_folio(struct folio *folio, dax_entry_t cookie)
{
- struct address_space *mapping = page->mapping;
- XA_STATE(xas, &mapping->i_pages, page->index);
+ struct address_space *mapping = folio->mapping;
+ XA_STATE(xas, &mapping->i_pages, folio->index);
if (S_ISCHR(mapping->host->i_mode))
return;
--- a/include/linux/dax.h~mm-convert-dax-lock-unlock-page-to-lock-unlock-folio
+++ a/include/linux/dax.h
@@ -159,8 +159,8 @@ int dax_writeback_mapping_range(struct a
struct page *dax_layout_busy_page(struct address_space *mapping);
struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end);
-dax_entry_t dax_lock_page(struct page *page);
-void dax_unlock_page(struct page *page, dax_entry_t cookie);
+dax_entry_t dax_lock_folio(struct folio *folio);
+void dax_unlock_folio(struct folio *folio, dax_entry_t cookie);
dax_entry_t dax_lock_mapping_entry(struct address_space *mapping,
unsigned long index, struct page **page);
void dax_unlock_mapping_entry(struct address_space *mapping,
@@ -182,14 +182,14 @@ static inline int dax_writeback_mapping_
return -EOPNOTSUPP;
}
-static inline dax_entry_t dax_lock_page(struct page *page)
+static inline dax_entry_t dax_lock_folio(struct folio *folio)
{
- if (IS_DAX(page->mapping->host))
+ if (IS_DAX(folio->mapping->host))
return ~0UL;
return 0;
}
-static inline void dax_unlock_page(struct page *page, dax_entry_t cookie)
+static inline void dax_unlock_folio(struct folio *folio, dax_entry_t cookie)
{
}
--- a/mm/memory-failure.c~mm-convert-dax-lock-unlock-page-to-lock-unlock-folio
+++ a/mm/memory-failure.c
@@ -1713,32 +1713,35 @@ static void unmap_and_kill(struct list_h
kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags);
}
+/*
+ * Only dev_pagemap pages get here, such as fsdax when the filesystem
+ * either do not claim or fails to claim a hwpoison event, or devdax.
+ * The fsdax pages are initialized per base page, and the devdax pages
+ * could be initialized either as base pages, or as compound pages with
+ * vmemmap optimization enabled. Devdax is simplistic in its dealing with
+ * hwpoison, such that, if a subpage of a compound page is poisoned,
+ * simply mark the compound head page is by far sufficient.
+ */
static int mf_generic_kill_procs(unsigned long long pfn, int flags,
struct dev_pagemap *pgmap)
{
- struct page *page = pfn_to_page(pfn);
+ struct folio *folio = pfn_folio(pfn);
LIST_HEAD(to_kill);
dax_entry_t cookie;
int rc = 0;
/*
- * Pages instantiated by device-dax (not filesystem-dax)
- * may be compound pages.
- */
- page = compound_head(page);
-
- /*
* Prevent the inode from being freed while we are interrogating
* the address_space, typically this would be handled by
* lock_page(), but dax pages do not use the page lock. This
* also prevents changes to the mapping of this pfn until
* poison signaling is complete.
*/
- cookie = dax_lock_page(page);
+ cookie = dax_lock_folio(folio);
if (!cookie)
return -EBUSY;
- if (hwpoison_filter(page)) {
+ if (hwpoison_filter(&folio->page)) {
rc = -EOPNOTSUPP;
goto unlock;
}
@@ -1760,7 +1763,7 @@ static int mf_generic_kill_procs(unsigne
* Use this flag as an indication that the dax page has been
* remapped UC to prevent speculative consumption of poison.
*/
- SetPageHWPoison(page);
+ SetPageHWPoison(&folio->page);
/*
* Unlike System-RAM there is no possibility to swap in a
@@ -1769,11 +1772,11 @@ static int mf_generic_kill_procs(unsigne
* SIGBUS (i.e. MF_MUST_KILL)
*/
flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
- collect_procs(page, &to_kill, true);
+ collect_procs(&folio->page, &to_kill, true);
- unmap_and_kill(&to_kill, pfn, page->mapping, page->index, flags);
+ unmap_and_kill(&to_kill, pfn, folio->mapping, folio->index, flags);
unlock:
- dax_unlock_page(page, cookie);
+ dax_unlock_folio(folio, cookie);
return rc;
}
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-make-lock_folio_maybe_drop_mmap-vma-lock-aware.patch
mm-call-wp_page_copy-under-the-vma-lock.patch
mm-handle-shared-faults-under-the-vma-lock.patch
mm-handle-cow-faults-under-the-vma-lock.patch
mm-handle-read-faults-under-the-vma-lock.patch
mm-handle-write-faults-to-ro-pages-under-the-vma-lock.patch
