[PATCH v5 16/17] treewide: remove PagePrivate() and PG_private from comments and docs
Zi Yan
ziy at nvidia.com
Sun Sep 20 19:28:12 PDT 2026
PG_private and PagePrivate() are no longer used. Adjust related comments
and documentations to refer to page/folio->private instead.
hugetlbfs_reserv.rst is outdated and left unchanged. It should be
rewritten.
Assisted-by: LLM
To: Ilya Dryomov <idryomov at gmail.com>
To: Alex Markuze <amarkuze at redhat.com>
To: Viacheslav Dubeyko <slava at dubeyko.com>
To: Trond Myklebust <trondmy at kernel.org>
To: Anna Schumaker <anna at kernel.org>
To: Richard Weinberger <richard at nod.at>
To: Andrew Morton <akpm at linux-foundation.org>
To: David Hildenbrand <david at kernel.org>
Cc: Zhihao Cheng <chengzhihao1 at huawei.com>
Cc: Lorenzo Stoakes <ljs at kernel.org>
Cc: "Liam R. Howlett" <liam at infradead.org>
Cc: Vlastimil Babka <vbabka at kernel.org>
Cc: Mike Rapoport <rppt at kernel.org>
Cc: Suren Baghdasaryan <surenb at google.com>
Cc: Michal Hocko <mhocko at suse.com>
Cc: ceph-devel at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-nfs at vger.kernel.org
Cc: linux-mtd at lists.infradead.org
Cc: linux-mm at kvack.org
Acked-by: David Hildenbrand (Arm) <david at kernel.org>
Signed-off-by: Zi Yan <ziy at nvidia.com>
---
Documentation/admin-guide/kdump/vmcoreinfo.rst | 2 +-
Documentation/filesystems/vfs.rst | 6 +++---
fs/nfs/file.c | 4 ++--
fs/ubifs/file.c | 8 ++++----
include/linux/mm.h | 15 ++++++++-------
include/linux/mm_types.h | 4 ++--
6 files changed, 20 insertions(+), 19 deletions(-)
diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
index 7663c610fe901..5f1df6d080508 100644
--- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
+++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
@@ -325,7 +325,7 @@ NR_FREE_PAGES
On linux-2.6.21 or later, the number of free pages is in
vm_stat[NR_FREE_PAGES]. Used to get the number of free pages.
-PG_lru|PG_private|PG_swapcache|PG_swapbacked|PG_hwpoison|PG_head_mask
+PG_lru|PG_swapcache|PG_swapbacked|PG_hwpoison|PG_head_mask
--------------------------------------------------------------------------
Page attributes. These flags are used to filter various unnecessary for
diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index d3a93eec3945f..dec7816303c6a 100644
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -649,8 +649,8 @@ Writeback.
The first can be used independently to the others. The VM can try to
release clean pages in order to reuse them. To do this it can call
-->release_folio on clean folios with the private
-flag set. Clean pages without PagePrivate and with no external references
+->release_folio on clean folios with folio->private set. Clean pages
+without folio->private set and with no external references
will be released without notice being given to the address_space.
To achieve this functionality, pages need to be placed on an LRU with
@@ -674,7 +674,7 @@ filemap_fdatawait_range, to wait for all writeback to complete.
An address_space handler may attach extra information to a page,
typically using the 'private' field in the 'struct page'. If such
-information is attached, the PG_Private flag should be set. This will
+information is attached, non-NULL 'private' field will
cause various VM routines to make extra calls into the address_space
handler to deal with that data.
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index e1bdd10b35f10..38f830a6467c9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -484,7 +484,7 @@ static int nfs_write_end(const struct kiocb *iocb,
* Partially or wholly invalidate a page
* - Release the private state associated with a page if undergoing complete
* page invalidation
- * - Called if either PG_private or PG_fscache is set on the page
+ * - Called if either folio->private or PG_fscache is set on the page
* - Caller holds page lock
*/
static void nfs_invalidate_folio(struct folio *folio, size_t offset,
@@ -555,7 +555,7 @@ static void nfs_check_dirty_writeback(struct folio *folio,
* Attempt to clear the private state associated with a page when an error
* occurs that requires the cached contents of an inode to be written back or
* destroyed
- * - Called if either PG_private or fscache is set on the page
+ * - Called if either page->private or fscache is set on the page
* - Caller holds page lock
* - Return 0 if successful, -error otherwise
*/
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index e73c28b12f97f..aa0298ce451ef 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -12,14 +12,14 @@
* This file implements VFS file and inode operations for regular files, device
* nodes and symlinks as well as address space operations.
*
- * UBIFS uses 2 page flags: @PG_private and @PG_checked. @PG_private is set if
+ * UBIFS uses folio->private and page flag @PG_checked. folio->private is set if
* the page is dirty and is used for optimization purposes - dirty pages are
- * not budgeted so the flag shows that 'ubifs_write_end()' should not release
+ * not budgeted so it shows that 'ubifs_write_end()' should not release
* the budget for this page. The @PG_checked flag is set if full budgeting is
* required for the page e.g., when it corresponds to a file hole or it is
* beyond the file size. The budgeting is done in 'ubifs_write_begin()', because
* it is OK to fail in this function, and the budget is released in
- * 'ubifs_write_end()'. So the @PG_private and @PG_checked flags carry
+ * 'ubifs_write_end()'. So the folio->private and the @PG_checked flag carry
* information about how the page was budgeted, to make it possible to release
* the budget properly.
*
@@ -1509,7 +1509,7 @@ static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf)
*
* At the moment we do not know whether the folio is dirty or not, so we
* assume that it is not and budget for a new folio. We could look at
- * the @PG_private flag and figure this out, but we may race with write
+ * folio->private and figure this out, but we may race with write
* back and the folio state may change by the time we lock it, so this
* would need additional care. We do not bother with this at the
* moment, although it might be good idea to do. Instead, we allocate
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d9392ac8dff9f..262d1de5c1161 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2048,20 +2048,21 @@ vm_fault_t finish_fault(struct vm_fault *vmf);
*
* A pagecache page contains an opaque `private' member, which belongs to the
* page's address_space. Usually, this is the address of a circular list of
- * the page's disk buffers. PG_private must be set to tell the VM to call
- * into the filesystem to release these pages.
+ * the page's disk buffers. It tells the VM to call into the filesystem to
+ * release these pages.
*
* A folio may belong to an inode's memory mapping. In this case,
* folio->mapping points to the inode, and folio->index is the file
* offset of the folio, in units of PAGE_SIZE.
*
- * If pagecache pages are not associated with an inode, they are said to be
- * anonymous pages. These may become associated with the swapcache, and in that
- * case PG_swapcache is set, and page->private is an offset into the swapcache.
+ * If pagecache folios are not associated with an inode, they are said to be
+ * anonymous folios. These may become associated with the swapcache, and in that
+ * case PG_swapcache is set, and folio->private is an offset into the swapcache.
*
* In either case (swapcache or inode backed), the pagecache itself holds one
- * reference to the page. Setting PG_private should also increment the
- * refcount. The each user mapping also has a reference to the page.
+ * reference to the folio. Attaching filesystem private data via
+ * folio_attach_private() also increments the refcount. Each user mapping also
+ * has a reference to the folio.
*
* The pagecache pages are stored in a per-mapping radix tree, which is
* rooted at mapping->i_pages, and indexed by offset.
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 5413bd10fff2c..9d6c945ba4104 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -108,7 +108,7 @@ struct page {
};
/**
* @private: Mapping-private opaque data.
- * Usually used for buffer_heads if PagePrivate.
+ * Usually used for buffer_heads.
* Used for swp_entry_t if swapcache flag set.
* Indicates order in the buddy system if PageBuddy
* or on pcp_llist.
@@ -675,7 +675,7 @@ static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc)
#define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
/*
- * page_private can be used on tail pages. However, PagePrivate is only
+ * page_private can be used on tail pages. However, it is only
* checked by the VM on the head page. So page_private on the tail pages
* should be used for data that's ancillary to the head page (eg attaching
* buffer heads to tail pages after attaching buffer heads to the head page)
--
2.53.0
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