[PATCH 15/15] mm: replace remaining &folio->page uses with folio_page() and helpers
From: Nilay Vaish
Date: Tue Sep 29 2026 - 18:01:16 EST
As part of the memdescs effort, struct folio will be allocated
separately from struct page and will no longer overlay the head page.
Convert the remaining &folio->page uses in mm/memory-failure.c,
mm/hwpoison-inject.c, mm/filemap.c, mm/gup_test.c, mm/memory_hotplug.c,
and mm/memremap.c to folio_page(folio, 0) (and folio_set_hwpoison() in
mf_generic_kill_procs()), and use ERR_CAST(folio) when returning an
error pointer as struct page * in do_read_cache_page() and
shmem_read_mapping_page_gfp().
In free_zone_device_folio() (mm/memremap.c), passing folio_page(folio, 0)
to wake_up_var() ensures the wake-up key continues to match the struct
page address that fs/dax.c waits on via ___wait_var_event(page, ...)
once struct folio is separated from struct page.
No functional change intended while struct folio overlays struct page.
Assisted-by: LLM
Signed-off-by: Nilay Vaish <nilayvaish@xxxxxxxxxx>
---
mm/filemap.c | 6 +++---
mm/gup_test.c | 6 ++++--
mm/hwpoison-inject.c | 2 +-
mm/memory-failure.c | 8 ++++----
mm/memory_hotplug.c | 2 +-
mm/memremap.c | 2 +-
mm/shmem.c | 2 +-
7 files changed, 15 insertions(+), 13 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index b74bc1e5015c..02e0c2af594c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -156,7 +156,7 @@ static void filemap_unaccount_folio(struct address_space *mapping,
if (!IS_ENABLED(CONFIG_DEBUG_VM) && unlikely(folio_mapped(folio))) {
pr_alert("BUG: Bad page cache in process %s pfn:%05lx\n",
current->comm, folio_pfn(folio));
- dump_page(&folio->page, "still mapped when deleted");
+ dump_page(folio_page(folio, 0), "still mapped when deleted");
dump_stack();
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
@@ -3888,7 +3888,7 @@ static vm_fault_t filemap_map_order0_folio(struct vm_fault *vmf,
unsigned long *rss)
{
vm_fault_t ret = 0;
- struct page *page = &folio->page;
+ struct page *page = folio_page(folio, 0);
if (PageHWPoison(page))
goto out;
@@ -4239,7 +4239,7 @@ static struct page *do_read_cache_page(struct address_space *mapping,
folio = do_read_cache_folio(mapping, index, filler, file, gfp);
if (IS_ERR(folio))
- return &folio->page;
+ return ERR_CAST(folio);
return folio_file_page(folio, index);
}
diff --git a/mm/gup_test.c b/mm/gup_test.c
index ba74bf3f4104..337b58221c79 100644
--- a/mm/gup_test.c
+++ b/mm/gup_test.c
@@ -59,13 +59,15 @@ static void verify_dma_pinned(unsigned int cmd, struct page **pages,
if (WARN(!folio_maybe_dma_pinned(folio),
"pages[%lu] is NOT dma-pinned\n", i)) {
- dump_page(&folio->page, "gup_test failure");
+ dump_page(folio_page(folio, 0),
+ "gup_test failure");
break;
} else if (cmd == PIN_LONGTERM_BENCHMARK &&
WARN(!folio_is_longterm_pinnable(folio),
"pages[%lu] is NOT pinnable but pinned\n",
i)) {
- dump_page(&folio->page, "gup_test failure");
+ dump_page(folio_page(folio, 0),
+ "gup_test failure");
break;
}
}
diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c
index a11222572f97..127e5d75aa0d 100644
--- a/mm/hwpoison-inject.c
+++ b/mm/hwpoison-inject.c
@@ -131,7 +131,7 @@ static int hwpoison_inject(void *data, u64 val)
* the targeted owner (or on a free page).
* memory_failure() will redo the check reliably inside page lock.
*/
- err = hwpoison_filter(&folio->page);
+ err = hwpoison_filter(folio_page(folio, 0));
if (err)
return 0;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 0c96eb511997..771a75eb5505 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1400,7 +1400,7 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags)
* unsupported type of folio in order to reduce the risk of unexpected
* races caused by taking a folio refcount.
*/
- if (!HWPoisonHandlable(&folio->page, flags))
+ if (!HWPoisonHandlable(folio_page(folio, 0), flags))
return -EBUSY;
if (folio_try_get(folio)) {
@@ -1777,7 +1777,7 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags,
if (!cookie)
return -EBUSY;
- if (hwpoison_filter(&folio->page)) {
+ if (hwpoison_filter(folio_page(folio, 0))) {
rc = -EOPNOTSUPP;
goto unlock;
}
@@ -1799,7 +1799,7 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags,
* Use this flag as an indication that the dax page has been
* remapped UC to prevent speculative consumption of poison.
*/
- SetPageHWPoison(&folio->page);
+ folio_set_hwpoison(folio);
/*
* Unlike System-RAM there is no possibility to swap in a
@@ -1808,7 +1808,7 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags,
* SIGBUS (i.e. MF_MUST_KILL)
*/
flags |= MF_ACTION_REQUIRED | MF_MUST_KILL;
- collect_procs(folio, &folio->page, &to_kill, true);
+ collect_procs(folio, folio_page(folio, 0), &to_kill, true);
unmap_and_kill(&to_kill, pfn, folio->mapping, folio->index, flags);
unlock:
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 796af1028ee2..47bf3b5d3ff2 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1952,7 +1952,7 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (__ratelimit(&migrate_rs)) {
pr_warn("migrating pfn %lx failed ret:%d\n",
folio_pfn(folio), ret);
- dump_page(&folio->page,
+ dump_page(folio_page(folio, 0),
"migration failure");
}
}
diff --git a/mm/memremap.c b/mm/memremap.c
index accba23aef28..70cfd3f05a25 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -467,7 +467,7 @@ void free_zone_device_folio(struct folio *folio)
break;
case MEMORY_DEVICE_FS_DAX:
- wake_up_var(&folio->page);
+ wake_up_var(folio_page(folio, 0));
break;
case MEMORY_DEVICE_PCI_P2PDMA:
diff --git a/mm/shmem.c b/mm/shmem.c
index 07b2855dfb7b..1dca70978ac9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -6195,7 +6195,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
struct page *page;
if (IS_ERR(folio))
- return &folio->page;
+ return ERR_CAST(folio);
page = folio_file_page(folio, index);
if (PageHWPoison(page)) {
--
2.56.0.rc1.315.gc6ed9934b7-goog