[PATCH 00/17] Initial conversion of NFS basic I/O to use folios

[PATCH 00/17] Initial conversion of NFS basic I/O to use folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

This set of patches represents an initial effort to convert the page
cache I/O in the NFS client to use native folio functionality. It should
allow the nfs_page structs and their helpers to carry folios (including
folios of order > 0) and to pass their data contents through to the RPC
layer.
Note that because O_DIRECT uses pages, we still need to support the
traditional page based I/O, and so the new struct nfs_page will carry
both types.
I did not touch the fscache code, but I expect that to be able to
continue to work with order 0 folios.

The plan is to merge this functionality with order 0 folios first, in
order to catch any regressions in existing functionality. Then we can
enable order n > 0 once we're happy about the stability (at least for
the non-fscache case).

At this point, the xfstests are all passing without any regressions on
my setup, so I'm throwing the patches over the fence to allow for wider
testing.
Please make sure, in particular to test pNFS if your server supports it.
I didn't have to make any changes to the pNFS code, and I don't expect
any trouble, but it would be good to have validation of that assumption.

Trond Myklebust (17):
  NFS: Fix for xfstests generic/208
  NFS: Add basic functionality for tracking folios in struct nfs_page
  NFS: Support folios in nfs_generic_pgio()
  NFS: Fix nfs_coalesce_size() to work with folios
  NFS: Add a helper to convert a struct nfs_page into an inode
  NFS: Convert the remaining pagelist helper functions to support folios
  NFS: Add a helper nfs_wb_folio()
  NFS: Convert buffered reads to use folios
  NFS: Convert the function nfs_wb_page() to use folios
  NFS: Convert buffered writes to use folios
  NFS: Remove unused function nfs_wb_page()
  NFS: Convert nfs_write_begin/end to use folios
  NFS: Fix up nfs_vm_page_mkwrite() for folios
  NFS: Clean up O_DIRECT request allocation
  NFS: fix up nfs_release_folio() to try to release the page
  NFS: Enable tracing of nfs_invalidate_folio() and nfs_launder_folio()
  NFS: Improve tracing of nfs_wb_folio()

 fs/nfs/direct.c          |  12 +-
 fs/nfs/file.c            | 124 +++++++------
 fs/nfs/internal.h        |  38 ++--
 fs/nfs/nfstrace.h        |  58 ++++--
 fs/nfs/pagelist.c        | 217 +++++++++++++++++-----
 fs/nfs/pnfs.h            |  10 +-
 fs/nfs/pnfs_nfs.c        |  18 +-
 fs/nfs/read.c            |  86 +++++----
 fs/nfs/write.c           | 380 ++++++++++++++++++++-------------------
 include/linux/nfs_fs.h   |   7 +-
 include/linux/nfs_page.h |  79 +++++++-
 11 files changed, 645 insertions(+), 384 deletions(-)

-- 
2.39.0

[PATCH 01/17] NFS: Fix for xfstests generic/208

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

If the same page and data is being used for multiple requests,
then ignore that when the request indicates we're reading from the start
of the page.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pagelist.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 317cedfa52bf..b4b3e80e64cd 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -920,6 +920,9 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 		req = nfs_list_entry(head->next);
 		nfs_list_move_request(req, &hdr->pages);
 
+		if (req->wb_pgbase == 0)
+			last_page = NULL;
+
 		if (!last_page || last_page != req->wb_page) {
 			pageused++;
 			if (pageused > pagecount)
-- 
2.39.0

[PATCH 02/17] NFS: Add basic functionality for tracking folios in struct nfs_page

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pagelist.c        |  5 +++--
 include/linux/nfs_page.h | 38 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index b4b3e80e64cd..f496774d9d97 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -500,9 +500,10 @@ nfs_create_subreq(struct nfs_page *req,
 {
 	struct nfs_page *last;
 	struct nfs_page *ret;
+	struct page *page = nfs_page_to_page(req, pgbase);
 
-	ret = __nfs_create_request(req->wb_lock_context, req->wb_page,
-			pgbase, offset, count);
+	ret = __nfs_create_request(req->wb_lock_context, page, pgbase, offset,
+				   count);
 	if (!IS_ERR(ret)) {
 		/* find the last request */
 		for (last = req->wb_head;
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index ba7e2e4b0926..d2ddc9a594c5 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -25,6 +25,7 @@
 enum {
 	PG_BUSY = 0,		/* nfs_{un}lock_request */
 	PG_MAPPED,		/* page private set for buffered io */
+	PG_FOLIO,		/* Tracking a folio (unset for O_DIRECT) */
 	PG_CLEAN,		/* write succeeded */
 	PG_COMMIT_TO_DS,	/* used by pnfs layouts */
 	PG_INODE_REF,		/* extra ref held by inode when in writeback */
@@ -41,7 +42,10 @@ enum {
 struct nfs_inode;
 struct nfs_page {
 	struct list_head	wb_list;	/* Defines state of page: */
-	struct page		*wb_page;	/* page to read in/write out */
+	union {
+		struct page	*wb_page;	/* page to read in/write out */
+		struct folio	*wb_folio;
+	};
 	struct nfs_lock_context	*wb_lock_context;	/* lock context info */
 	pgoff_t			wb_index;	/* Offset >> PAGE_SHIFT */
 	unsigned int		wb_offset,	/* Offset & ~PAGE_MASK */
@@ -153,6 +157,38 @@ extern	int nfs_page_set_headlock(struct nfs_page *req);
 extern void nfs_page_clear_headlock(struct nfs_page *req);
 extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *);
 
+/**
+ * nfs_page_to_folio - Retrieve a struct folio for the request
+ * @req: pointer to a struct nfs_page
+ *
+ * If a folio was assigned to @req, then return it, otherwise return NULL.
+ */
+static inline struct folio *nfs_page_to_folio(const struct nfs_page *req)
+{
+	if (test_bit(PG_FOLIO, &req->wb_flags))
+		return req->wb_folio;
+	return NULL;
+}
+
+/**
+ * nfs_page_to_page - Retrieve a struct page for the request
+ * @req: pointer to a struct nfs_page
+ * @pgbase: folio byte offset
+ *
+ * Return the page containing the byte that is at offset @pgbase relative
+ * to the start of the folio.
+ * Note: The request starts at offset @req->wb_pgbase.
+ */
+static inline struct page *nfs_page_to_page(const struct nfs_page *req,
+					    size_t pgbase)
+{
+	struct folio *folio = nfs_page_to_folio(req);
+
+	if (folio == NULL)
+		return req->wb_page;
+	return folio_page(folio, pgbase >> PAGE_SHIFT);
+}
+
 /*
  * Lock the page of an asynchronous request
  */
-- 
2.39.0

[PATCH 03/17] NFS: Support folios in nfs_generic_pgio()

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Add support for multi-page folios in the generic NFS i/o engine.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/internal.h |  7 +++--
 fs/nfs/pagelist.c | 68 +++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 60 insertions(+), 15 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index ae7d4a8c728c..6197b165c8c8 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -807,11 +807,10 @@ unsigned char nfs_umode_to_dtype(umode_t mode)
  * Determine the number of pages in an array of length 'len' and
  * with a base offset of 'base'
  */
-static inline
-unsigned int nfs_page_array_len(unsigned int base, size_t len)
+static inline unsigned int nfs_page_array_len(unsigned int base, size_t len)
 {
-	return ((unsigned long)len + (unsigned long)base +
-		PAGE_SIZE - 1) >> PAGE_SHIFT;
+	return ((unsigned long)len + (unsigned long)base + PAGE_SIZE - 1) >>
+	       PAGE_SHIFT;
 }
 
 /*
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index f496774d9d97..33b8d636dd78 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -31,6 +31,42 @@
 static struct kmem_cache *nfs_page_cachep;
 static const struct rpc_call_ops nfs_pgio_common_ops;
 
+struct nfs_page_iter_page {
+	const struct nfs_page *req;
+	size_t count;
+};
+
+static void nfs_page_iter_page_init(struct nfs_page_iter_page *i,
+				    const struct nfs_page *req)
+{
+	i->req = req;
+	i->count = 0;
+}
+
+static void nfs_page_iter_page_advance(struct nfs_page_iter_page *i, size_t sz)
+{
+	const struct nfs_page *req = i->req;
+	size_t tmp = i->count + sz;
+
+	i->count = (tmp < req->wb_bytes) ? tmp : req->wb_bytes;
+}
+
+static struct page *nfs_page_iter_page_get(struct nfs_page_iter_page *i)
+{
+	const struct nfs_page *req = i->req;
+	struct page *page;
+
+	if (i->count != req->wb_bytes) {
+		size_t base = i->count + req->wb_pgbase;
+		size_t len = PAGE_SIZE - offset_in_page(base);
+
+		page = nfs_page_to_page(req, base);
+		nfs_page_iter_page_advance(i, len);
+		return page;
+	}
+	return NULL;
+}
+
 static struct nfs_pgio_mirror *
 nfs_pgio_get_mirror(struct nfs_pageio_descriptor *desc, u32 idx)
 {
@@ -693,13 +729,14 @@ EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
 /**
  * nfs_pgio_rpcsetup - Set up arguments for a pageio call
  * @hdr: The pageio hdr
+ * @pgbase: base
  * @count: Number of bytes to read
  * @how: How to commit data (writes only)
  * @cinfo: Commit information for the call (writes only)
  */
-static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
-			      unsigned int count,
-			      int how, struct nfs_commit_info *cinfo)
+static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr, unsigned int pgbase,
+			      unsigned int count, int how,
+			      struct nfs_commit_info *cinfo)
 {
 	struct nfs_page *req = hdr->req;
 
@@ -710,7 +747,7 @@ static void nfs_pgio_rpcsetup(struct nfs_pgio_header *hdr,
 	hdr->args.offset = req_offset(req);
 	/* pnfs_set_layoutcommit needs this */
 	hdr->mds_offset = hdr->args.offset;
-	hdr->args.pgbase = req->wb_pgbase;
+	hdr->args.pgbase = pgbase;
 	hdr->args.pages  = hdr->page_array.pagevec;
 	hdr->args.count  = count;
 	hdr->args.context = get_nfs_open_context(nfs_req_openctx(req));
@@ -896,9 +933,10 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 	struct nfs_commit_info cinfo;
 	struct nfs_page_array *pg_array = &hdr->page_array;
 	unsigned int pagecount, pageused;
+	unsigned int pg_base = offset_in_page(mirror->pg_base);
 	gfp_t gfp_flags = nfs_io_gfp_mask();
 
-	pagecount = nfs_page_array_len(mirror->pg_base, mirror->pg_count);
+	pagecount = nfs_page_array_len(pg_base, mirror->pg_count);
 	pg_array->npages = pagecount;
 
 	if (pagecount <= ARRAY_SIZE(pg_array->page_array))
@@ -918,19 +956,26 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 	last_page = NULL;
 	pageused = 0;
 	while (!list_empty(head)) {
+		struct nfs_page_iter_page i;
+		struct page *page;
+
 		req = nfs_list_entry(head->next);
 		nfs_list_move_request(req, &hdr->pages);
 
 		if (req->wb_pgbase == 0)
 			last_page = NULL;
 
-		if (!last_page || last_page != req->wb_page) {
-			pageused++;
-			if (pageused > pagecount)
-				break;
-			*pages++ = last_page = req->wb_page;
+		nfs_page_iter_page_init(&i, req);
+		while ((page = nfs_page_iter_page_get(&i)) != NULL) {
+			if (last_page != page) {
+				pageused++;
+				if (pageused > pagecount)
+					goto full;
+				*pages++ = last_page = page;
+			}
 		}
 	}
+full:
 	if (WARN_ON_ONCE(pageused != pagecount)) {
 		nfs_pgio_error(hdr);
 		desc->pg_error = -EINVAL;
@@ -942,7 +987,8 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 		desc->pg_ioflags &= ~FLUSH_COND_STABLE;
 
 	/* Set up the argument struct */
-	nfs_pgio_rpcsetup(hdr, mirror->pg_count, desc->pg_ioflags, &cinfo);
+	nfs_pgio_rpcsetup(hdr, pg_base, mirror->pg_count, desc->pg_ioflags,
+			  &cinfo);
 	desc->pg_rpc_callops = &nfs_pgio_common_ops;
 	return 0;
 }
-- 
2.39.0

[PATCH 04/17] NFS: Fix nfs_coalesce_size() to work with folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Use the helper folio_size() where appropriate.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pagelist.c        | 28 +++++++++++++++++++---------
 include/linux/nfs_page.h | 15 +++++++++++++++
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 33b8d636dd78..30722cbcf5f4 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1084,6 +1084,24 @@ static bool nfs_match_lock_context(const struct nfs_lock_context *l1,
 	return l1->lockowner == l2->lockowner;
 }
 
+static bool nfs_page_is_contiguous(const struct nfs_page *prev,
+				   const struct nfs_page *req)
+{
+	size_t prev_end = prev->wb_pgbase + prev->wb_bytes;
+
+	if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+		return false;
+	if (req->wb_pgbase == 0)
+		return prev_end == nfs_page_max_length(prev);
+	if (req->wb_pgbase == prev_end) {
+		struct folio *folio = nfs_page_to_folio(req);
+		if (folio)
+			return folio == nfs_page_to_folio(prev);
+		return req->wb_page == prev->wb_page;
+	}
+	return false;
+}
+
 /**
  * nfs_coalesce_size - test two requests for compatibility
  * @prev: pointer to nfs_page
@@ -1112,16 +1130,8 @@ static unsigned int nfs_coalesce_size(struct nfs_page *prev,
 		    !nfs_match_lock_context(req->wb_lock_context,
 					    prev->wb_lock_context))
 			return 0;
-		if (req_offset(req) != req_offset(prev) + prev->wb_bytes)
+		if (!nfs_page_is_contiguous(prev, req))
 			return 0;
-		if (req->wb_page == prev->wb_page) {
-			if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes)
-				return 0;
-		} else {
-			if (req->wb_pgbase != 0 ||
-			    prev->wb_pgbase + prev->wb_bytes != PAGE_SIZE)
-				return 0;
-		}
 	}
 	return pgio->pg_ops->pg_test(pgio, prev, req);
 }
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index d2ddc9a594c5..192071a6e5f6 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -189,6 +189,21 @@ static inline struct page *nfs_page_to_page(const struct nfs_page *req,
 	return folio_page(folio, pgbase >> PAGE_SHIFT);
 }
 
+/**
+ * nfs_page_max_length - Retrieve the maximum possible length for a request
+ * @req: pointer to a struct nfs_page
+ *
+ * Returns the maximum possible length of a request
+ */
+static inline size_t nfs_page_max_length(const struct nfs_page *req)
+{
+	struct folio *folio = nfs_page_to_folio(req);
+
+	if (folio == NULL)
+		return PAGE_SIZE;
+	return folio_size(folio);
+}
+
 /*
  * Lock the page of an asynchronous request
  */
-- 
2.39.0

[PATCH 05/17] NFS: Add a helper to convert a struct nfs_page into an inode

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Replace all the open coded calls to page_file_mapping(req->wb_page)->host.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pagelist.c        |  2 +-
 fs/nfs/write.c           |  7 +++----
 include/linux/nfs_page.h | 13 +++++++++++++
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 30722cbcf5f4..18a10f43612f 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -426,7 +426,7 @@ nfs_page_group_init(struct nfs_page *req, struct nfs_page *prev)
 		 * has extra ref from the write/commit path to handle handoff
 		 * between write and commit lists. */
 		if (test_bit(PG_INODE_REF, &prev->wb_head->wb_flags)) {
-			inode = page_file_mapping(req->wb_page)->host;
+			inode = nfs_page_to_inode(req);
 			set_bit(PG_INODE_REF, &req->wb_flags);
 			kref_get(&req->wb_kref);
 			atomic_long_inc(&NFS_I(inode)->nrequests);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f41d24b54fd1..f624b3d98cf7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -421,7 +421,7 @@ static void nfs_set_page_writeback(struct page *page)
 
 static void nfs_end_page_writeback(struct nfs_page *req)
 {
-	struct inode *inode = page_file_mapping(req->wb_page)->host;
+	struct inode *inode = nfs_page_to_inode(req);
 	struct nfs_server *nfss = NFS_SERVER(inode);
 	bool is_done;
 
@@ -592,8 +592,7 @@ nfs_lock_and_join_requests(struct page *page)
 
 static void nfs_write_error(struct nfs_page *req, int error)
 {
-	trace_nfs_write_error(page_file_mapping(req->wb_page)->host, req,
-			      error);
+	trace_nfs_write_error(nfs_page_to_inode(req), req, error);
 	nfs_mapping_set_error(req->wb_page, error);
 	nfs_inode_remove_request(req);
 	nfs_end_page_writeback(req);
@@ -1420,7 +1419,7 @@ static void nfs_initiate_write(struct nfs_pgio_header *hdr,
  */
 static void nfs_redirty_request(struct nfs_page *req)
 {
-	struct nfs_inode *nfsi = NFS_I(page_file_mapping(req->wb_page)->host);
+	struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req));
 
 	/* Bump the transmission count */
 	req->wb_nio++;
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 192071a6e5f6..b0b03ec4a209 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -189,6 +189,19 @@ static inline struct page *nfs_page_to_page(const struct nfs_page *req,
 	return folio_page(folio, pgbase >> PAGE_SHIFT);
 }
 
+/**
+ * nfs_page_to_inode - Retrieve an inode for the request
+ * @req: pointer to a struct nfs_page
+ */
+static inline struct inode *nfs_page_to_inode(const struct nfs_page *req)
+{
+	struct folio *folio = nfs_page_to_folio(req);
+
+	if (folio == NULL)
+		return page_file_mapping(req->wb_page)->host;
+	return folio_file_mapping(folio)->host;
+}
+
 /**
  * nfs_page_max_length - Retrieve the maximum possible length for a request
  * @req: pointer to a struct nfs_page
-- 
2.39.0

[PATCH 06/17] NFS: Convert the remaining pagelist helper functions to support folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Allow creation of subrequests from a request that is carrying a folio.
Add helpers to set up and tear down requests carrying folios.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/pagelist.c | 72 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 50 insertions(+), 22 deletions(-)

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 18a10f43612f..520556d6bfe2 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -466,10 +466,9 @@ nfs_page_group_destroy(struct kref *kref)
 		nfs_release_request(head);
 }
 
-static struct nfs_page *
-__nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
-		   unsigned int pgbase, unsigned int offset,
-		   unsigned int count)
+static struct nfs_page *nfs_page_create(struct nfs_lock_context *l_ctx,
+					unsigned int pgbase, pgoff_t index,
+					unsigned int offset, unsigned int count)
 {
 	struct nfs_page		*req;
 	struct nfs_open_context *ctx = l_ctx->open_context;
@@ -488,19 +487,32 @@ __nfs_create_request(struct nfs_lock_context *l_ctx, struct page *page,
 	/* Initialize the request struct. Initially, we assume a
 	 * long write-back delay. This will be adjusted in
 	 * update_nfs_request below if the region is not locked. */
-	req->wb_page    = page;
-	if (page) {
-		req->wb_index = page_index(page);
-		get_page(page);
-	}
-	req->wb_offset  = offset;
-	req->wb_pgbase	= pgbase;
-	req->wb_bytes   = count;
+	req->wb_pgbase = pgbase;
+	req->wb_index = index;
+	req->wb_offset = offset;
+	req->wb_bytes = count;
 	kref_init(&req->wb_kref);
 	req->wb_nio = 0;
 	return req;
 }
 
+static void nfs_page_assign_folio(struct nfs_page *req, struct folio *folio)
+{
+	if (folio != NULL) {
+		req->wb_folio = folio;
+		folio_get(folio);
+		set_bit(PG_FOLIO, &req->wb_flags);
+	}
+}
+
+static void nfs_page_assign_page(struct nfs_page *req, struct page *page)
+{
+	if (page != NULL) {
+		req->wb_page = page;
+		get_page(page);
+	}
+}
+
 /**
  * nfs_create_request - Create an NFS read/write request.
  * @ctx: open context to use
@@ -521,9 +533,11 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
 
 	if (IS_ERR(l_ctx))
 		return ERR_CAST(l_ctx);
-	ret = __nfs_create_request(l_ctx, page, offset, offset, count);
-	if (!IS_ERR(ret))
+	ret = nfs_page_create(l_ctx, offset, page_index(page), offset, count);
+	if (!IS_ERR(ret)) {
+		nfs_page_assign_page(ret, page);
 		nfs_page_group_init(ret, NULL);
+	}
 	nfs_put_lock_context(l_ctx);
 	return ret;
 }
@@ -536,11 +550,16 @@ nfs_create_subreq(struct nfs_page *req,
 {
 	struct nfs_page *last;
 	struct nfs_page *ret;
+	struct folio *folio = nfs_page_to_folio(req);
 	struct page *page = nfs_page_to_page(req, pgbase);
 
-	ret = __nfs_create_request(req->wb_lock_context, page, pgbase, offset,
-				   count);
+	ret = nfs_page_create(req->wb_lock_context, pgbase, req->wb_index,
+			      offset, count);
 	if (!IS_ERR(ret)) {
+		if (folio)
+			nfs_page_assign_folio(ret, folio);
+		else
+			nfs_page_assign_page(ret, page);
 		/* find the last request */
 		for (last = req->wb_head;
 		     last->wb_this_page != req->wb_head;
@@ -548,7 +567,6 @@ nfs_create_subreq(struct nfs_page *req,
 			;
 
 		nfs_lock_request(ret);
-		ret->wb_index = req->wb_index;
 		nfs_page_group_init(ret, last);
 		ret->wb_nio = req->wb_nio;
 	}
@@ -587,11 +605,16 @@ void nfs_unlock_and_release_request(struct nfs_page *req)
  */
 static void nfs_clear_request(struct nfs_page *req)
 {
+	struct folio *folio = nfs_page_to_folio(req);
 	struct page *page = req->wb_page;
 	struct nfs_lock_context *l_ctx = req->wb_lock_context;
 	struct nfs_open_context *ctx;
 
-	if (page != NULL) {
+	if (folio != NULL) {
+		folio_put(folio);
+		req->wb_folio = NULL;
+		clear_bit(PG_FOLIO, &req->wb_flags);
+	} else if (page != NULL) {
 		put_page(page);
 		req->wb_page = NULL;
 	}
@@ -1471,16 +1494,21 @@ void nfs_pageio_cond_complete(struct nfs_pageio_descriptor *desc, pgoff_t index)
 {
 	struct nfs_pgio_mirror *mirror;
 	struct nfs_page *prev;
+	struct folio *folio;
 	u32 midx;
 
 	for (midx = 0; midx < desc->pg_mirror_count; midx++) {
 		mirror = nfs_pgio_get_mirror(desc, midx);
 		if (!list_empty(&mirror->pg_list)) {
 			prev = nfs_list_entry(mirror->pg_list.prev);
-			if (index != prev->wb_index + 1) {
-				nfs_pageio_complete(desc);
-				break;
-			}
+			folio = nfs_page_to_folio(prev);
+			if (folio) {
+				if (index == folio_next_index(folio))
+					continue;
+			} else if (index == prev->wb_index + 1)
+				continue;
+			nfs_pageio_complete(desc);
+			break;
 		}
 	}
 }
-- 
2.39.0

[PATCH 07/17] NFS: Add a helper nfs_wb_folio()

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

...and use it in nfs_launder_folio().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c          |  2 +-
 fs/nfs/write.c         | 13 +++++++++++++
 include/linux/nfs_fs.h |  1 +
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index d8ec889a4b3f..8704bd071d3a 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -469,7 +469,7 @@ static int nfs_launder_folio(struct folio *folio)
 		inode->i_ino, folio_pos(folio));
 
 	folio_wait_fscache(folio);
-	return nfs_wb_page(inode, &folio->page);
+	return nfs_wb_folio(inode, folio);
 }
 
 static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index f624b3d98cf7..0fbb119022d9 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2106,6 +2106,19 @@ int nfs_wb_page(struct inode *inode, struct page *page)
 	return ret;
 }
 
+/**
+ * nfs_wb_folio - Write back all requests on one page
+ * @inode: pointer to page
+ * @folio: pointer to folio
+ *
+ * Assumes that the folio has been locked by the caller, and will
+ * not unlock it.
+ */
+int nfs_wb_folio(struct inode *inode, struct folio *folio)
+{
+	return nfs_wb_page(inode, &folio->page);
+}
+
 #ifdef CONFIG_MIGRATION
 int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
 		struct folio *src, enum migrate_mode mode)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index d92fdfd2444c..66b5de42f6b8 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -578,6 +578,7 @@ extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned
  */
 extern int nfs_sync_inode(struct inode *inode);
 extern int nfs_wb_all(struct inode *inode);
+extern int nfs_wb_folio(struct inode *inode, struct folio *folio);
 extern int nfs_wb_page(struct inode *inode, struct page *page);
 int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio);
 extern int  nfs_commit_inode(struct inode *, int);
-- 
2.39.0

[PATCH 08/17] NFS: Convert buffered reads to use folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/internal.h        | 18 +++++++++
 fs/nfs/nfstrace.h        | 12 +++---
 fs/nfs/pagelist.c        | 30 ++++++++++++++
 fs/nfs/read.c            | 86 ++++++++++++++++++++--------------------
 include/linux/nfs_page.h |  4 ++
 5 files changed, 100 insertions(+), 50 deletions(-)

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 6197b165c8c8..529b87336ffa 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -794,6 +794,24 @@ unsigned int nfs_page_length(struct page *page)
 	return 0;
 }
 
+/*
+ * Determine the number of bytes of data the page contains
+ */
+static inline size_t nfs_folio_length(struct folio *folio)
+{
+	loff_t i_size = i_size_read(folio_file_mapping(folio)->host);
+
+	if (i_size > 0) {
+		pgoff_t index = folio_index(folio) >> folio_order(folio);
+		pgoff_t end_index = (i_size - 1) >> folio_shift(folio);
+		if (index < end_index)
+			return folio_size(folio);
+		if (index == end_index)
+			return offset_in_folio(folio, i_size - 1) + 1;
+	}
+	return 0;
+}
+
 /*
  * Convert a umode to a dirent->d_type
  */
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 8c6cc58679ff..d83226e45335 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -936,10 +936,10 @@ TRACE_EVENT(nfs_sillyrename_unlink,
 TRACE_EVENT(nfs_aop_readpage,
 		TP_PROTO(
 			const struct inode *inode,
-			struct page *page
+			struct folio *folio
 		),
 
-		TP_ARGS(inode, page),
+		TP_ARGS(inode, folio),
 
 		TP_STRUCT__entry(
 			__field(dev_t, dev)
@@ -956,7 +956,7 @@ TRACE_EVENT(nfs_aop_readpage,
 			__entry->fileid = nfsi->fileid;
 			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
 			__entry->version = inode_peek_iversion_raw(inode);
-			__entry->offset = page_index(page) << PAGE_SHIFT;
+			__entry->offset = folio_file_pos(folio);
 		),
 
 		TP_printk(
@@ -971,11 +971,11 @@ TRACE_EVENT(nfs_aop_readpage,
 TRACE_EVENT(nfs_aop_readpage_done,
 		TP_PROTO(
 			const struct inode *inode,
-			struct page *page,
+			struct folio *folio,
 			int ret
 		),
 
-		TP_ARGS(inode, page, ret),
+		TP_ARGS(inode, folio, ret),
 
 		TP_STRUCT__entry(
 			__field(dev_t, dev)
@@ -993,7 +993,7 @@ TRACE_EVENT(nfs_aop_readpage_done,
 			__entry->fileid = nfsi->fileid;
 			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
 			__entry->version = inode_peek_iversion_raw(inode);
-			__entry->offset = page_index(page) << PAGE_SHIFT;
+			__entry->offset = folio_file_pos(folio);
 			__entry->ret = ret;
 		),
 
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 520556d6bfe2..6706e0df1963 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -542,6 +542,36 @@ nfs_create_request(struct nfs_open_context *ctx, struct page *page,
 	return ret;
 }
 
+/**
+ * nfs_page_create_from_folio - Create an NFS read/write request.
+ * @ctx: open context to use
+ * @folio: folio to write
+ * @offset: starting offset within the folio for the write
+ * @count: number of bytes to read/write
+ *
+ * The page must be locked by the caller. This makes sure we never
+ * create two different requests for the same page.
+ * User should ensure it is safe to sleep in this function.
+ */
+struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
+					    struct folio *folio,
+					    unsigned int offset,
+					    unsigned int count)
+{
+	struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
+	struct nfs_page *ret;
+
+	if (IS_ERR(l_ctx))
+		return ERR_CAST(l_ctx);
+	ret = nfs_page_create(l_ctx, offset, folio_index(folio), offset, count);
+	if (!IS_ERR(ret)) {
+		nfs_page_assign_folio(ret, folio);
+		nfs_page_group_init(ret, NULL);
+	}
+	nfs_put_lock_context(l_ctx);
+	return ret;
+}
+
 static struct nfs_page *
 nfs_create_subreq(struct nfs_page *req,
 		  unsigned int pgbase,
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 8ae2c8d1219d..bf4154f9b48c 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -49,12 +49,11 @@ static void nfs_readhdr_free(struct nfs_pgio_header *rhdr)
 	kmem_cache_free(nfs_rdata_cachep, rhdr);
 }
 
-static
-int nfs_return_empty_page(struct page *page)
+static int nfs_return_empty_folio(struct folio *folio)
 {
-	zero_user(page, 0, PAGE_SIZE);
-	SetPageUptodate(page);
-	unlock_page(page);
+	folio_zero_segment(folio, 0, folio_size(folio));
+	folio_mark_uptodate(folio);
+	folio_unlock(folio);
 	return 0;
 }
 
@@ -111,18 +110,18 @@ EXPORT_SYMBOL_GPL(nfs_pageio_reset_read_mds);
 static void nfs_readpage_release(struct nfs_page *req, int error)
 {
 	struct inode *inode = d_inode(nfs_req_openctx(req)->dentry);
-	struct page *page = req->wb_page;
+	struct folio *folio = nfs_page_to_folio(req);
 
 	dprintk("NFS: read done (%s/%llu %d@%lld)\n", inode->i_sb->s_id,
 		(unsigned long long)NFS_FILEID(inode), req->wb_bytes,
 		(long long)req_offset(req));
 
 	if (nfs_error_is_fatal_on_server(error) && error != -ETIMEDOUT)
-		SetPageError(page);
+		folio_set_error(folio);
 	if (nfs_page_group_sync_on_bit(req, PG_UNLOCKPAGE)) {
-		if (PageUptodate(page))
-			nfs_fscache_write_page(inode, page);
-		unlock_page(page);
+		if (folio_test_uptodate(folio))
+			nfs_fscache_write_page(inode, &folio->page);
+		folio_unlock(folio);
 	}
 	nfs_release_request(req);
 }
@@ -135,7 +134,7 @@ struct nfs_readdesc {
 static void nfs_page_group_set_uptodate(struct nfs_page *req)
 {
 	if (nfs_page_group_sync_on_bit(req, PG_UPTODATE))
-		SetPageUptodate(req->wb_page);
+		folio_mark_uptodate(nfs_page_to_folio(req));
 }
 
 static void nfs_read_completion(struct nfs_pgio_header *hdr)
@@ -147,7 +146,7 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
 		goto out;
 	while (!list_empty(&hdr->pages)) {
 		struct nfs_page *req = nfs_list_entry(hdr->pages.next);
-		struct page *page = req->wb_page;
+		struct folio *folio = nfs_page_to_folio(req);
 		unsigned long start = req->wb_pgbase;
 		unsigned long end = req->wb_pgbase + req->wb_bytes;
 
@@ -157,14 +156,14 @@ static void nfs_read_completion(struct nfs_pgio_header *hdr)
 			if (bytes > hdr->good_bytes) {
 				/* nothing in this request was good, so zero
 				 * the full extent of the request */
-				zero_user_segment(page, start, end);
+				folio_zero_segment(folio, start, end);
 
 			} else if (hdr->good_bytes - bytes < req->wb_bytes) {
 				/* part of this request has good bytes, but
 				 * not all. zero the bad bytes */
 				start += hdr->good_bytes - bytes;
 				WARN_ON(start < req->wb_pgbase);
-				zero_user_segment(page, start, end);
+				folio_zero_segment(folio, start, end);
 			}
 		}
 		error = 0;
@@ -281,33 +280,34 @@ static void nfs_readpage_result(struct rpc_task *task,
 		nfs_readpage_retry(task, hdr);
 }
 
-static int
-readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
+static int readpage_async_filler(struct nfs_readdesc *desc, struct folio *folio)
 {
-	struct inode *inode = page_file_mapping(page)->host;
-	unsigned int rsize = NFS_SERVER(inode)->rsize;
+	struct inode *inode = folio_file_mapping(folio)->host;
+	struct nfs_server *server = NFS_SERVER(inode);
+	size_t fsize = folio_size(folio);
+	unsigned int rsize = server->rsize;
 	struct nfs_page *new;
 	unsigned int len, aligned_len;
 	int error;
 
-	len = nfs_page_length(page);
+	len = nfs_folio_length(folio);
 	if (len == 0)
-		return nfs_return_empty_page(page);
+		return nfs_return_empty_folio(folio);
 
-	aligned_len = min_t(unsigned int, ALIGN(len, rsize), PAGE_SIZE);
+	aligned_len = min_t(unsigned int, ALIGN(len, rsize), fsize);
 
-	if (!IS_SYNC(page->mapping->host)) {
-		error = nfs_fscache_read_page(page->mapping->host, page);
+	if (!IS_SYNC(inode)) {
+		error = nfs_fscache_read_page(inode, &folio->page);
 		if (error == 0)
 			goto out_unlock;
 	}
 
-	new = nfs_create_request(desc->ctx, page, 0, aligned_len);
+	new = nfs_page_create_from_folio(desc->ctx, folio, 0, aligned_len);
 	if (IS_ERR(new))
 		goto out_error;
 
-	if (len < PAGE_SIZE)
-		zero_user_segment(page, len, PAGE_SIZE);
+	if (len < fsize)
+		folio_zero_segment(folio, len, fsize);
 	if (!nfs_pageio_add_request(&desc->pgio, new)) {
 		nfs_list_remove_request(new);
 		error = desc->pgio.pg_error;
@@ -318,7 +318,7 @@ readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
 out_error:
 	error = PTR_ERR(new);
 out_unlock:
-	unlock_page(page);
+	folio_unlock(folio);
 out:
 	return error;
 }
@@ -331,25 +331,24 @@ readpage_async_filler(struct nfs_readdesc *desc, struct page *page)
  */
 int nfs_read_folio(struct file *file, struct folio *folio)
 {
-	struct page *page = &folio->page;
 	struct nfs_readdesc desc;
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = file_inode(file);
 	int ret;
 
-	trace_nfs_aop_readpage(inode, page);
+	trace_nfs_aop_readpage(inode, folio);
 	nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
 
 	/*
 	 * Try to flush any pending writes to the file..
 	 *
-	 * NOTE! Because we own the page lock, there cannot
+	 * NOTE! Because we own the folio lock, there cannot
 	 * be any new pending writes generated at this point
-	 * for this page (other pages can be written to).
+	 * for this folio (other folios can be written to).
 	 */
-	ret = nfs_wb_page(inode, page);
+	ret = nfs_wb_folio(inode, folio);
 	if (ret)
 		goto out_unlock;
-	if (PageUptodate(page))
+	if (folio_test_uptodate(folio))
 		goto out_unlock;
 
 	ret = -ESTALE;
@@ -368,24 +367,24 @@ int nfs_read_folio(struct file *file, struct folio *folio)
 	nfs_pageio_init_read(&desc.pgio, inode, false,
 			     &nfs_async_read_completion_ops);
 
-	ret = readpage_async_filler(&desc, page);
+	ret = readpage_async_filler(&desc, folio);
 	if (ret)
 		goto out;
 
 	nfs_pageio_complete_read(&desc.pgio);
 	ret = desc.pgio.pg_error < 0 ? desc.pgio.pg_error : 0;
 	if (!ret) {
-		ret = wait_on_page_locked_killable(page);
-		if (!PageUptodate(page) && !ret)
+		ret = folio_wait_locked_killable(folio);
+		if (!folio_test_uptodate(folio) && !ret)
 			ret = xchg(&desc.ctx->error, 0);
 	}
 out:
 	put_nfs_open_context(desc.ctx);
-	trace_nfs_aop_readpage_done(inode, page, ret);
+	trace_nfs_aop_readpage_done(inode, folio, ret);
 	return ret;
 out_unlock:
-	unlock_page(page);
-	trace_nfs_aop_readpage_done(inode, page, ret);
+	folio_unlock(folio);
+	trace_nfs_aop_readpage_done(inode, folio, ret);
 	return ret;
 }
 
@@ -395,7 +394,7 @@ void nfs_readahead(struct readahead_control *ractl)
 	struct file *file = ractl->file;
 	struct nfs_readdesc desc;
 	struct inode *inode = ractl->mapping->host;
-	struct page *page;
+	struct folio *folio;
 	int ret;
 
 	trace_nfs_aop_readahead(inode, readahead_pos(ractl), nr_pages);
@@ -416,9 +415,8 @@ void nfs_readahead(struct readahead_control *ractl)
 	nfs_pageio_init_read(&desc.pgio, inode, false,
 			     &nfs_async_read_completion_ops);
 
-	while ((page = readahead_page(ractl)) != NULL) {
-		ret = readpage_async_filler(&desc, page);
-		put_page(page);
+	while ((folio = readahead_folio(ractl)) != NULL) {
+		ret = readpage_async_filler(&desc, folio);
 		if (ret)
 			break;
 	}
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index b0b03ec4a209..3c71493d5cc3 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -125,6 +125,10 @@ extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
 					    struct page *page,
 					    unsigned int offset,
 					    unsigned int count);
+extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
+						   struct folio *folio,
+						   unsigned int offset,
+						   unsigned int count);
 extern	void nfs_release_request(struct nfs_page *);
 
 
-- 
2.39.0

[PATCH 09/17] NFS: Convert the function nfs_wb_page() to use folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/write.c | 35 ++++++++++++++++-------------------
 1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 0fbb119022d9..14f98c452595 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2069,13 +2069,18 @@ int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
 	return ret;
 }
 
-/*
- * Write back all requests on one page - we do this before reading it.
+/**
+ * nfs_wb_folio - Write back all requests on one page
+ * @inode: pointer to page
+ * @folio: pointer to folio
+ *
+ * Assumes that the folio has been locked by the caller, and will
+ * not unlock it.
  */
-int nfs_wb_page(struct inode *inode, struct page *page)
+int nfs_wb_folio(struct inode *inode, struct folio *folio)
 {
-	loff_t range_start = page_file_offset(page);
-	loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
+	loff_t range_start = folio_file_pos(folio);
+	loff_t range_end = range_start + (loff_t)folio_size(folio) - 1;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
 		.nr_to_write = 0,
@@ -2087,15 +2092,15 @@ int nfs_wb_page(struct inode *inode, struct page *page)
 	trace_nfs_writeback_page_enter(inode);
 
 	for (;;) {
-		wait_on_page_writeback(page);
-		if (clear_page_dirty_for_io(page)) {
-			ret = nfs_writepage_locked(page, &wbc);
+		folio_wait_writeback(folio);
+		if (folio_clear_dirty_for_io(folio)) {
+			ret = nfs_writepage_locked(folio, &wbc);
 			if (ret < 0)
 				goto out_error;
 			continue;
 		}
 		ret = 0;
-		if (!PagePrivate(page))
+		if (!folio_test_private(folio))
 			break;
 		ret = nfs_commit_inode(inode, FLUSH_SYNC);
 		if (ret < 0)
@@ -2106,17 +2111,9 @@ int nfs_wb_page(struct inode *inode, struct page *page)
 	return ret;
 }
 
-/**
- * nfs_wb_folio - Write back all requests on one page
- * @inode: pointer to page
- * @folio: pointer to folio
- *
- * Assumes that the folio has been locked by the caller, and will
- * not unlock it.
- */
-int nfs_wb_folio(struct inode *inode, struct folio *folio)
+int nfs_wb_page(struct inode *inode, struct page *page)
 {
-	return nfs_wb_page(inode, &folio->page);
+	return nfs_wb_folio(inode, page_folio(page));
 }
 
 #ifdef CONFIG_MIGRATION
-- 
2.39.0

[PATCH 10/17] NFS: Convert buffered writes to use folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c          |  14 +-
 fs/nfs/internal.h      |  13 +-
 fs/nfs/pnfs.h          |  10 +-
 fs/nfs/pnfs_nfs.c      |  18 +--
 fs/nfs/write.c         | 348 +++++++++++++++++++++--------------------
 include/linux/nfs_fs.h |   5 +-
 6 files changed, 209 insertions(+), 199 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 8704bd071d3a..9fbe27214da0 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -319,6 +319,7 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 	int ret;
 	pgoff_t index = pos >> PAGE_SHIFT;
 	struct page *page;
+	struct folio *folio;
 	int once_thru = 0;
 
 	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
@@ -329,15 +330,16 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 	if (!page)
 		return -ENOMEM;
 	*pagep = page;
+	folio = page_folio(page);
 
-	ret = nfs_flush_incompatible(file, page);
+	ret = nfs_flush_incompatible(file, folio);
 	if (ret) {
 		unlock_page(page);
 		put_page(page);
 	} else if (!once_thru &&
 		   nfs_want_read_modify_write(file, page, pos, len)) {
 		once_thru = 1;
-		ret = nfs_read_folio(file, page_folio(page));
+		ret = nfs_read_folio(file, folio);
 		put_page(page);
 		if (!ret)
 			goto start;
@@ -351,6 +353,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 {
 	unsigned offset = pos & (PAGE_SIZE - 1);
 	struct nfs_open_context *ctx = nfs_file_open_context(file);
+	struct folio *folio = page_folio(page);
 	int status;
 
 	dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
@@ -376,7 +379,7 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 			zero_user_segment(page, pglen, PAGE_SIZE);
 	}
 
-	status = nfs_updatepage(file, page, offset, copied);
+	status = nfs_update_folio(file, folio, offset, copied);
 
 	unlock_page(page);
 	put_page(page);
@@ -552,6 +555,7 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 	unsigned pagelen;
 	vm_fault_t ret = VM_FAULT_NOPAGE;
 	struct address_space *mapping;
+	struct folio *folio = page_folio(page);
 
 	dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
 		filp, filp->f_mapping->host->i_ino,
@@ -582,8 +586,8 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 		goto out_unlock;
 
 	ret = VM_FAULT_LOCKED;
-	if (nfs_flush_incompatible(filp, page) == 0 &&
-	    nfs_updatepage(filp, page, 0, pagelen) == 0)
+	if (nfs_flush_incompatible(filp, folio) == 0 &&
+	    nfs_update_folio(filp, folio, 0, pagelen) == 0)
 		goto out;
 
 	ret = VM_FAULT_SIGBUS;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 529b87336ffa..239ae5084774 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -760,17 +760,18 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
  * Record the page as unstable (an extra writeback period) and mark its
  * inode as dirty.
  */
-static inline
-void nfs_mark_page_unstable(struct page *page, struct nfs_commit_info *cinfo)
+static inline void nfs_folio_mark_unstable(struct folio *folio,
+					   struct nfs_commit_info *cinfo)
 {
-	if (!cinfo->dreq) {
-		struct inode *inode = page_file_mapping(page)->host;
+	if (folio && !cinfo->dreq) {
+		struct inode *inode = folio_file_mapping(folio)->host;
+		long nr = folio_nr_pages(folio);
 
 		/* This page is really still in write-back - just that the
 		 * writeback is happening on the server now.
 		 */
-		inc_node_page_state(page, NR_WRITEBACK);
-		inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
+		node_stat_mod_folio(folio, NR_WRITEBACK, nr);
+		wb_stat_mod(&inode_to_bdi(inode)->wb, WB_WRITEBACK, nr);
 		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
 	}
 }
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index e3e6a41f19de..d886c8226d8f 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -193,7 +193,7 @@ struct pnfs_commit_ops {
 	void (*recover_commit_reqs) (struct list_head *list,
 				     struct nfs_commit_info *cinfo);
 	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
-						struct page *page);
+						struct folio *folio);
 };
 
 struct pnfs_layout_hdr {
@@ -395,7 +395,7 @@ void pnfs_generic_rw_release(void *data);
 void pnfs_generic_recover_commit_reqs(struct list_head *dst,
 				      struct nfs_commit_info *cinfo);
 struct nfs_page *pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo,
-						 struct page *page);
+						 struct folio *folio);
 int pnfs_generic_commit_pagelist(struct inode *inode,
 				 struct list_head *mds_pages,
 				 int how,
@@ -557,13 +557,13 @@ pnfs_recover_commit_reqs(struct list_head *head, struct nfs_commit_info *cinfo)
 
 static inline struct nfs_page *
 pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
-			struct page *page)
+			struct folio *folio)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 
 	if (!fl_cinfo->ops || !fl_cinfo->ops->search_commit_reqs)
 		return NULL;
-	return fl_cinfo->ops->search_commit_reqs(cinfo, page);
+	return fl_cinfo->ops->search_commit_reqs(cinfo, folio);
 }
 
 /* Should the pNFS client commit and return the layout upon a setattr */
@@ -864,7 +864,7 @@ pnfs_recover_commit_reqs(struct list_head *head, struct nfs_commit_info *cinfo)
 
 static inline struct nfs_page *
 pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
-			struct page *page)
+			struct folio *folio)
 {
 	return NULL;
 }
diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
index 5d035dd2d7bf..a0112ad4937a 100644
--- a/fs/nfs/pnfs_nfs.c
+++ b/fs/nfs/pnfs_nfs.c
@@ -353,7 +353,7 @@ EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
 
 static struct nfs_page *
 pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
-		unsigned int nbuckets, struct page *page)
+			       unsigned int nbuckets, struct folio *folio)
 {
 	struct nfs_page *req;
 	struct pnfs_commit_bucket *b;
@@ -363,11 +363,11 @@ pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
 	 * request is found */
 	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
 		list_for_each_entry(req, &b->written, wb_list) {
-			if (req->wb_page == page)
+			if (nfs_page_to_folio(req) == folio)
 				return req->wb_head;
 		}
 		list_for_each_entry(req, &b->committing, wb_list) {
-			if (req->wb_page == page)
+			if (nfs_page_to_folio(req) == folio)
 				return req->wb_head;
 		}
 	}
@@ -375,14 +375,14 @@ pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
 }
 
 /* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head request
- *				   for @page
+ *				   for @folio
  * @cinfo - commit info for current inode
- * @page - page to search for matching head request
+ * @folio - page to search for matching head request
  *
  * Return: the head request if one is found, otherwise %NULL.
  */
-struct nfs_page *
-pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+struct nfs_page *pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo,
+						 struct folio *folio)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 	struct pnfs_commit_array *array;
@@ -390,7 +390,7 @@ pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page
 
 	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
 		req = pnfs_bucket_search_commit_reqs(array->buckets,
-				array->nbuckets, page);
+						     array->nbuckets, folio);
 		if (req)
 			return req;
 	}
@@ -1180,7 +1180,7 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
 
 	nfs_request_add_commit_list_locked(req, list, cinfo);
 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
-	nfs_mark_page_unstable(req->wb_page, cinfo);
+	nfs_folio_mark_unstable(nfs_page_to_folio(req), cinfo);
 	return;
 out_resched:
 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 14f98c452595..581ad66636a7 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -63,7 +63,7 @@ static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
 				      struct inode *inode);
 static struct nfs_page *
 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
-						struct page *page);
+						struct folio *folio);
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;
@@ -170,31 +170,28 @@ nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode)
 	return 0;
 }
 
-static struct nfs_page *
-nfs_page_private_request(struct page *page)
+static struct nfs_page *nfs_folio_private_request(struct folio *folio)
 {
-	if (!PagePrivate(page))
-		return NULL;
-	return (struct nfs_page *)page_private(page);
+	return folio_get_private(folio);
 }
 
-/*
- * nfs_page_find_head_request_locked - find head request associated with @page
+/**
+ * nfs_folio_find_private_request - find head request associated with a folio
+ * @folio: pointer to folio
  *
  * must be called while holding the inode lock.
  *
  * returns matching head request with reference held, or NULL if not found.
  */
-static struct nfs_page *
-nfs_page_find_private_request(struct page *page)
+static struct nfs_page *nfs_folio_find_private_request(struct folio *folio)
 {
-	struct address_space *mapping = page_file_mapping(page);
+	struct address_space *mapping = folio_file_mapping(folio);
 	struct nfs_page *req;
 
-	if (!PagePrivate(page))
+	if (!folio_test_private(folio))
 		return NULL;
 	spin_lock(&mapping->private_lock);
-	req = nfs_page_private_request(page);
+	req = nfs_folio_private_request(folio);
 	if (req) {
 		WARN_ON_ONCE(req->wb_head != req);
 		kref_get(&req->wb_kref);
@@ -203,18 +200,17 @@ nfs_page_find_private_request(struct page *page)
 	return req;
 }
 
-static struct nfs_page *
-nfs_page_find_swap_request(struct page *page)
+static struct nfs_page *nfs_folio_find_swap_request(struct folio *folio)
 {
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = folio_file_mapping(folio)->host;
 	struct nfs_inode *nfsi = NFS_I(inode);
 	struct nfs_page *req = NULL;
-	if (!PageSwapCache(page))
+	if (!folio_test_swapcache(folio))
 		return NULL;
 	mutex_lock(&nfsi->commit_mutex);
-	if (PageSwapCache(page)) {
+	if (folio_test_swapcache(folio)) {
 		req = nfs_page_search_commits_for_head_request_locked(nfsi,
-			page);
+								      folio);
 		if (req) {
 			WARN_ON_ONCE(req->wb_head != req);
 			kref_get(&req->wb_kref);
@@ -224,29 +220,30 @@ nfs_page_find_swap_request(struct page *page)
 	return req;
 }
 
-/*
- * nfs_page_find_head_request - find head request associated with @page
+/**
+ * nfs_folio_find_head_request - find head request associated with a folio
+ * @folio: pointer to folio
  *
  * returns matching head request with reference held, or NULL if not found.
  */
-static struct nfs_page *nfs_page_find_head_request(struct page *page)
+static struct nfs_page *nfs_folio_find_head_request(struct folio *folio)
 {
 	struct nfs_page *req;
 
-	req = nfs_page_find_private_request(page);
+	req = nfs_folio_find_private_request(folio);
 	if (!req)
-		req = nfs_page_find_swap_request(page);
+		req = nfs_folio_find_swap_request(folio);
 	return req;
 }
 
-static struct nfs_page *nfs_find_and_lock_page_request(struct page *page)
+static struct nfs_page *nfs_folio_find_and_lock_request(struct folio *folio)
 {
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = folio_file_mapping(folio)->host;
 	struct nfs_page *req, *head;
 	int ret;
 
 	for (;;) {
-		req = nfs_page_find_head_request(page);
+		req = nfs_folio_find_head_request(folio);
 		if (!req)
 			return req;
 		head = nfs_page_group_lock_head(req);
@@ -260,9 +257,9 @@ static struct nfs_page *nfs_find_and_lock_page_request(struct page *page)
 			return ERR_PTR(ret);
 		}
 		/* Ensure that nobody removed the request before we locked it */
-		if (head == nfs_page_private_request(page))
+		if (head == nfs_folio_private_request(folio))
 			break;
-		if (PageSwapCache(page))
+		if (folio_test_swapcache(folio))
 			break;
 		nfs_unlock_and_release_request(head);
 	}
@@ -270,18 +267,19 @@ static struct nfs_page *nfs_find_and_lock_page_request(struct page *page)
 }
 
 /* Adjust the file length if we're writing beyond the end */
-static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count)
+static void nfs_grow_file(struct folio *folio, unsigned int offset,
+			  unsigned int count)
 {
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = folio_file_mapping(folio)->host;
 	loff_t end, i_size;
 	pgoff_t end_index;
 
 	spin_lock(&inode->i_lock);
 	i_size = i_size_read(inode);
-	end_index = (i_size - 1) >> PAGE_SHIFT;
-	if (i_size > 0 && page_index(page) < end_index)
+	end_index = ((i_size - 1) >> folio_shift(folio)) << folio_order(folio);
+	if (i_size > 0 && folio_index(folio) < end_index)
 		goto out;
-	end = page_file_offset(page) + ((loff_t)offset+count);
+	end = folio_file_pos(folio) + (loff_t)offset + (loff_t)count;
 	if (i_size >= end)
 		goto out;
 	trace_nfs_size_grow(inode, end);
@@ -307,11 +305,11 @@ static void nfs_set_pageerror(struct address_space *mapping)
 	spin_unlock(&inode->i_lock);
 }
 
-static void nfs_mapping_set_error(struct page *page, int error)
+static void nfs_mapping_set_error(struct folio *folio, int error)
 {
-	struct address_space *mapping = page_file_mapping(page);
+	struct address_space *mapping = folio_file_mapping(folio);
 
-	SetPageError(page);
+	folio_set_error(folio);
 	filemap_set_wb_err(mapping, error);
 	if (mapping->host)
 		errseq_set(&mapping->host->i_sb->s_wb_err,
@@ -358,9 +356,9 @@ nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset)
  */
 static bool nfs_page_group_covers_page(struct nfs_page *req)
 {
+	unsigned int len = nfs_folio_length(nfs_page_to_folio(req));
 	struct nfs_page *tmp;
 	unsigned int pos = 0;
-	unsigned int len = nfs_page_length(req->wb_page);
 
 	nfs_page_group_lock(req);
 
@@ -380,11 +378,13 @@ static bool nfs_page_group_covers_page(struct nfs_page *req)
  */
 static void nfs_mark_uptodate(struct nfs_page *req)
 {
-	if (PageUptodate(req->wb_page))
+	struct folio *folio = nfs_page_to_folio(req);
+
+	if (folio_test_uptodate(folio))
 		return;
 	if (!nfs_page_group_covers_page(req))
 		return;
-	SetPageUptodate(req->wb_page);
+	folio_mark_uptodate(folio);
 }
 
 static int wb_priority(struct writeback_control *wbc)
@@ -406,35 +406,34 @@ int nfs_congestion_kb;
 #define NFS_CONGESTION_OFF_THRESH	\
 	(NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2))
 
-static void nfs_set_page_writeback(struct page *page)
+static void nfs_folio_set_writeback(struct folio *folio)
 {
-	struct inode *inode = page_file_mapping(page)->host;
-	struct nfs_server *nfss = NFS_SERVER(inode);
-	int ret = test_set_page_writeback(page);
-
-	WARN_ON_ONCE(ret != 0);
+	struct nfs_server *nfss = NFS_SERVER(folio_file_mapping(folio)->host);
 
-	if (atomic_long_inc_return(&nfss->writeback) >
-			NFS_CONGESTION_ON_THRESH)
+	folio_start_writeback(folio);
+	if (atomic_long_inc_return(&nfss->writeback) > NFS_CONGESTION_ON_THRESH)
 		nfss->write_congested = 1;
 }
 
-static void nfs_end_page_writeback(struct nfs_page *req)
+static void nfs_folio_end_writeback(struct folio *folio)
 {
-	struct inode *inode = nfs_page_to_inode(req);
-	struct nfs_server *nfss = NFS_SERVER(inode);
-	bool is_done;
+	struct nfs_server *nfss = NFS_SERVER(folio_file_mapping(folio)->host);
 
-	is_done = nfs_page_group_sync_on_bit(req, PG_WB_END);
-	nfs_unlock_request(req);
-	if (!is_done)
-		return;
-
-	end_page_writeback(req->wb_page);
-	if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH)
+	folio_end_writeback(folio);
+	if (atomic_long_dec_return(&nfss->writeback) <
+	    NFS_CONGESTION_OFF_THRESH)
 		nfss->write_congested = 0;
 }
 
+static void nfs_page_end_writeback(struct nfs_page *req)
+{
+	if (nfs_page_group_sync_on_bit(req, PG_WB_END)) {
+		nfs_unlock_request(req);
+		nfs_folio_end_writeback(nfs_page_to_folio(req));
+	} else
+		nfs_unlock_request(req);
+}
+
 /*
  * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests
  *
@@ -549,7 +548,7 @@ nfs_join_page_group(struct nfs_page *head, struct inode *inode)
 
 /*
  * nfs_lock_and_join_requests - join all subreqs to the head req
- * @page: the page used to lookup the "page group" of nfs_page structures
+ * @folio: the folio used to lookup the "page group" of nfs_page structures
  *
  * This function joins all sub requests to the head request by first
  * locking all requests in the group, cancelling any pending operations
@@ -559,13 +558,12 @@ nfs_join_page_group(struct nfs_page *head, struct inode *inode)
  *
  * Returns a locked, referenced pointer to the head request - which after
  * this call is guaranteed to be the only request associated with the page.
- * Returns NULL if no requests are found for @page, or a ERR_PTR if an
+ * Returns NULL if no requests are found for @folio, or a ERR_PTR if an
  * error was encountered.
  */
-static struct nfs_page *
-nfs_lock_and_join_requests(struct page *page)
+static struct nfs_page *nfs_lock_and_join_requests(struct folio *folio)
 {
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = folio_file_mapping(folio)->host;
 	struct nfs_page *head;
 	int ret;
 
@@ -574,7 +572,7 @@ nfs_lock_and_join_requests(struct page *page)
 	 * reference to the whole page group - the group will not be destroyed
 	 * until the head reference is released.
 	 */
-	head = nfs_find_and_lock_page_request(page);
+	head = nfs_folio_find_and_lock_request(folio);
 	if (IS_ERR_OR_NULL(head))
 		return head;
 
@@ -593,9 +591,9 @@ nfs_lock_and_join_requests(struct page *page)
 static void nfs_write_error(struct nfs_page *req, int error)
 {
 	trace_nfs_write_error(nfs_page_to_inode(req), req, error);
-	nfs_mapping_set_error(req->wb_page, error);
+	nfs_mapping_set_error(nfs_page_to_folio(req), error);
 	nfs_inode_remove_request(req);
-	nfs_end_page_writeback(req);
+	nfs_page_end_writeback(req);
 	nfs_release_request(req);
 }
 
@@ -603,21 +601,21 @@ static void nfs_write_error(struct nfs_page *req, int error)
  * Find an associated nfs write request, and prepare to flush it out
  * May return an error if the user signalled nfs_wait_on_request().
  */
-static int nfs_page_async_flush(struct page *page,
+static int nfs_page_async_flush(struct folio *folio,
 				struct writeback_control *wbc,
 				struct nfs_pageio_descriptor *pgio)
 {
 	struct nfs_page *req;
 	int ret = 0;
 
-	req = nfs_lock_and_join_requests(page);
+	req = nfs_lock_and_join_requests(folio);
 	if (!req)
 		goto out;
 	ret = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out;
 
-	nfs_set_page_writeback(page);
+	nfs_folio_set_writeback(folio);
 	WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags));
 
 	/* If there is a fatal error that covers this write, just exit */
@@ -635,12 +633,12 @@ static int nfs_page_async_flush(struct page *page,
 			goto out_launder;
 		if (wbc->sync_mode == WB_SYNC_NONE)
 			ret = AOP_WRITEPAGE_ACTIVATE;
-		redirty_page_for_writepage(wbc, page);
+		folio_redirty_for_writepage(wbc, folio);
 		nfs_redirty_request(req);
 		pgio->pg_error = 0;
 	} else
-		nfs_add_stats(page_file_mapping(page)->host,
-				NFSIOS_WRITEPAGES, 1);
+		nfs_add_stats(folio_file_mapping(folio)->host,
+			      NFSIOS_WRITEPAGES, 1);
 out:
 	return ret;
 out_launder:
@@ -648,21 +646,21 @@ static int nfs_page_async_flush(struct page *page,
 	return 0;
 }
 
-static int nfs_do_writepage(struct page *page, struct writeback_control *wbc,
+static int nfs_do_writepage(struct folio *folio, struct writeback_control *wbc,
 			    struct nfs_pageio_descriptor *pgio)
 {
-	nfs_pageio_cond_complete(pgio, page_index(page));
-	return nfs_page_async_flush(page, wbc, pgio);
+	nfs_pageio_cond_complete(pgio, folio_index(folio));
+	return nfs_page_async_flush(folio, wbc, pgio);
 }
 
 /*
  * Write an mmapped page to the server.
  */
-static int nfs_writepage_locked(struct page *page,
+static int nfs_writepage_locked(struct folio *folio,
 				struct writeback_control *wbc)
 {
 	struct nfs_pageio_descriptor pgio;
-	struct inode *inode = page_file_mapping(page)->host;
+	struct inode *inode = folio_file_mapping(folio)->host;
 	int err;
 
 	if (wbc->sync_mode == WB_SYNC_NONE &&
@@ -670,9 +668,9 @@ static int nfs_writepage_locked(struct page *page,
 		return AOP_WRITEPAGE_ACTIVATE;
 
 	nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE);
-	nfs_pageio_init_write(&pgio, inode, 0,
-				false, &nfs_async_write_completion_ops);
-	err = nfs_do_writepage(page, wbc, &pgio);
+	nfs_pageio_init_write(&pgio, inode, 0, false,
+			      &nfs_async_write_completion_ops);
+	err = nfs_do_writepage(folio, wbc, &pgio);
 	pgio.pg_error = 0;
 	nfs_pageio_complete(&pgio);
 	return err;
@@ -680,19 +678,22 @@ static int nfs_writepage_locked(struct page *page,
 
 int nfs_writepage(struct page *page, struct writeback_control *wbc)
 {
+	struct folio *folio = page_folio(page);
 	int ret;
 
-	ret = nfs_writepage_locked(page, wbc);
+	ret = nfs_writepage_locked(folio, wbc);
 	if (ret != AOP_WRITEPAGE_ACTIVATE)
 		unlock_page(page);
 	return ret;
 }
 
-static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data)
+static int nfs_writepages_callback(struct page *page,
+				   struct writeback_control *wbc, void *data)
 {
+	struct folio *folio = page_folio(page);
 	int ret;
 
-	ret = nfs_do_writepage(page, wbc, data);
+	ret = nfs_do_writepage(folio, wbc, data);
 	if (ret != AOP_WRITEPAGE_ACTIVATE)
 		unlock_page(page);
 	return ret;
@@ -748,10 +749,11 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 /*
  * Insert a write request into an inode
  */
-static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
+static void nfs_inode_add_request(struct nfs_page *req)
 {
-	struct address_space *mapping = page_file_mapping(req->wb_page);
-	struct nfs_inode *nfsi = NFS_I(inode);
+	struct folio *folio = nfs_page_to_folio(req);
+	struct address_space *mapping = folio_file_mapping(folio);
+	struct nfs_inode *nfsi = NFS_I(mapping->host);
 
 	WARN_ON_ONCE(req->wb_this_page != req);
 
@@ -763,10 +765,10 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 	 * with invalidate/truncate.
 	 */
 	spin_lock(&mapping->private_lock);
-	if (likely(!PageSwapCache(req->wb_page))) {
+	if (likely(!folio_test_swapcache(folio))) {
 		set_bit(PG_MAPPED, &req->wb_flags);
-		SetPagePrivate(req->wb_page);
-		set_page_private(req->wb_page, (unsigned long)req);
+		folio_set_private(folio);
+		folio->private = req;
 	}
 	spin_unlock(&mapping->private_lock);
 	atomic_long_inc(&nfsi->nrequests);
@@ -783,47 +785,43 @@ static void nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
  */
 static void nfs_inode_remove_request(struct nfs_page *req)
 {
-	struct address_space *mapping = page_file_mapping(req->wb_page);
-	struct inode *inode = mapping->host;
-	struct nfs_inode *nfsi = NFS_I(inode);
-	struct nfs_page *head;
-
 	if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) {
-		head = req->wb_head;
+		struct folio *folio = nfs_page_to_folio(req->wb_head);
+		struct address_space *mapping = folio_file_mapping(folio);
 
 		spin_lock(&mapping->private_lock);
-		if (likely(head->wb_page && !PageSwapCache(head->wb_page))) {
-			set_page_private(head->wb_page, 0);
-			ClearPagePrivate(head->wb_page);
-			clear_bit(PG_MAPPED, &head->wb_flags);
+		if (likely(folio && !folio_test_swapcache(folio))) {
+			folio->private = NULL;
+			folio_clear_private(folio);
+			clear_bit(PG_MAPPED, &req->wb_head->wb_flags);
 		}
 		spin_unlock(&mapping->private_lock);
 	}
 
 	if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) {
 		nfs_release_request(req);
-		atomic_long_dec(&nfsi->nrequests);
+		atomic_long_dec(&NFS_I(nfs_page_to_inode(req))->nrequests);
 	}
 }
 
-static void
-nfs_mark_request_dirty(struct nfs_page *req)
+static void nfs_mark_request_dirty(struct nfs_page *req)
 {
-	if (req->wb_page)
-		__set_page_dirty_nobuffers(req->wb_page);
+	struct folio *folio = nfs_page_to_folio(req);
+	if (folio)
+		filemap_dirty_folio(folio_mapping(folio), folio);
 }
 
 /*
  * nfs_page_search_commits_for_head_request_locked
  *
- * Search through commit lists on @inode for the head request for @page.
+ * Search through commit lists on @inode for the head request for @folio.
  * Must be called while holding the inode (which is cinfo) lock.
  *
  * Returns the head request if found, or NULL if not found.
  */
 static struct nfs_page *
 nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
-						struct page *page)
+						struct folio *folio)
 {
 	struct nfs_page *freq, *t;
 	struct nfs_commit_info cinfo;
@@ -832,13 +830,13 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
 	nfs_init_cinfo_from_inode(&cinfo, inode);
 
 	/* search through pnfs commit lists */
-	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	freq = pnfs_search_commit_reqs(inode, &cinfo, folio);
 	if (freq)
 		return freq->wb_head;
 
 	/* Linearly search the commit list for the correct request */
 	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
-		if (freq->wb_page == page)
+		if (nfs_page_to_folio(freq) == folio)
 			return freq->wb_head;
 	}
 
@@ -886,8 +884,7 @@ nfs_request_add_commit_list(struct nfs_page *req, struct nfs_commit_info *cinfo)
 	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
 	nfs_request_add_commit_list_locked(req, &cinfo->mds->list, cinfo);
 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
-	if (req->wb_page)
-		nfs_mark_page_unstable(req->wb_page, cinfo);
+	nfs_folio_mark_unstable(nfs_page_to_folio(req), cinfo);
 }
 EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
 
@@ -946,12 +943,15 @@ nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg,
 	nfs_request_add_commit_list(req, cinfo);
 }
 
-static void
-nfs_clear_page_commit(struct page *page)
+static void nfs_folio_clear_commit(struct folio *folio)
 {
-	dec_node_page_state(page, NR_WRITEBACK);
-	dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb,
-		    WB_WRITEBACK);
+	if (folio) {
+		long nr = folio_nr_pages(folio);
+
+		node_stat_mod_folio(folio, NR_WRITEBACK, -nr);
+		wb_stat_mod(&inode_to_bdi(folio_file_mapping(folio)->host)->wb,
+			    WB_WRITEBACK, -nr);
+	}
 }
 
 /* Called holding the request lock on @req */
@@ -969,7 +969,7 @@ nfs_clear_request_commit(struct nfs_page *req)
 			nfs_request_remove_commit_list(req, &cinfo);
 		}
 		mutex_unlock(&NFS_I(inode)->commit_mutex);
-		nfs_clear_page_commit(req->wb_page);
+		nfs_folio_clear_commit(nfs_page_to_folio(req));
 	}
 }
 
@@ -1001,7 +1001,8 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
 		if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) &&
 		    (hdr->good_bytes < bytes)) {
 			trace_nfs_comp_error(hdr->inode, req, hdr->error);
-			nfs_mapping_set_error(req->wb_page, hdr->error);
+			nfs_mapping_set_error(nfs_page_to_folio(req),
+					      hdr->error);
 			goto remove_req;
 		}
 		if (nfs_write_need_commit(hdr)) {
@@ -1015,7 +1016,7 @@ static void nfs_write_completion(struct nfs_pgio_header *hdr)
 remove_req:
 		nfs_inode_remove_request(req);
 next:
-		nfs_end_page_writeback(req);
+		nfs_page_end_writeback(req);
 		nfs_release_request(req);
 	}
 out:
@@ -1091,10 +1092,9 @@ nfs_scan_commit(struct inode *inode, struct list_head *dst,
  * If the attempt fails, then the existing request is flushed out
  * to disk.
  */
-static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
-		struct page *page,
-		unsigned int offset,
-		unsigned int bytes)
+static struct nfs_page *nfs_try_to_update_request(struct folio *folio,
+						  unsigned int offset,
+						  unsigned int bytes)
 {
 	struct nfs_page *req;
 	unsigned int rqend;
@@ -1103,7 +1103,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
 
 	end = offset + bytes;
 
-	req = nfs_lock_and_join_requests(page);
+	req = nfs_lock_and_join_requests(folio);
 	if (IS_ERR_OR_NULL(req))
 		return req;
 
@@ -1136,7 +1136,7 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
 	 */
 	nfs_mark_request_dirty(req);
 	nfs_unlock_and_release_request(req);
-	error = nfs_wb_page(inode, page);
+	error = nfs_wb_folio(folio_file_mapping(folio)->host, folio);
 	return (error < 0) ? ERR_PTR(error) : NULL;
 }
 
@@ -1147,40 +1147,42 @@ static struct nfs_page *nfs_try_to_update_request(struct inode *inode,
  * if we have to add a new request. Also assumes that the caller has
  * already called nfs_flush_incompatible() if necessary.
  */
-static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx,
-		struct page *page, unsigned int offset, unsigned int bytes)
+static struct nfs_page *nfs_setup_write_request(struct nfs_open_context *ctx,
+						struct folio *folio,
+						unsigned int offset,
+						unsigned int bytes)
 {
-	struct inode *inode = page_file_mapping(page)->host;
-	struct nfs_page	*req;
+	struct nfs_page *req;
 
-	req = nfs_try_to_update_request(inode, page, offset, bytes);
+	req = nfs_try_to_update_request(folio, offset, bytes);
 	if (req != NULL)
 		goto out;
-	req = nfs_create_request(ctx, page, offset, bytes);
+	req = nfs_page_create_from_folio(ctx, folio, offset, bytes);
 	if (IS_ERR(req))
 		goto out;
-	nfs_inode_add_request(inode, req);
+	nfs_inode_add_request(req);
 out:
 	return req;
 }
 
-static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page,
-		unsigned int offset, unsigned int count)
+static int nfs_writepage_setup(struct nfs_open_context *ctx,
+			       struct folio *folio, unsigned int offset,
+			       unsigned int count)
 {
-	struct nfs_page	*req;
+	struct nfs_page *req;
 
-	req = nfs_setup_write_request(ctx, page, offset, count);
+	req = nfs_setup_write_request(ctx, folio, offset, count);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 	/* Update file length */
-	nfs_grow_file(page, offset, count);
+	nfs_grow_file(folio, offset, count);
 	nfs_mark_uptodate(req);
 	nfs_mark_request_dirty(req);
 	nfs_unlock_and_release_request(req);
 	return 0;
 }
 
-int nfs_flush_incompatible(struct file *file, struct page *page)
+int nfs_flush_incompatible(struct file *file, struct folio *folio)
 {
 	struct nfs_open_context *ctx = nfs_file_open_context(file);
 	struct nfs_lock_context *l_ctx;
@@ -1196,12 +1198,12 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
 	 * dropped page.
 	 */
 	do {
-		req = nfs_page_find_head_request(page);
+		req = nfs_folio_find_head_request(folio);
 		if (req == NULL)
 			return 0;
 		l_ctx = req->wb_lock_context;
-		do_flush = req->wb_page != page ||
-			!nfs_match_open_context(nfs_req_openctx(req), ctx);
+		do_flush = nfs_page_to_folio(req) != folio ||
+			   !nfs_match_open_context(nfs_req_openctx(req), ctx);
 		if (l_ctx && flctx &&
 		    !(list_empty_careful(&flctx->flc_posix) &&
 		      list_empty_careful(&flctx->flc_flock))) {
@@ -1210,7 +1212,7 @@ int nfs_flush_incompatible(struct file *file, struct page *page)
 		nfs_release_request(req);
 		if (!do_flush)
 			return 0;
-		status = nfs_wb_page(page_file_mapping(page)->host, page);
+		status = nfs_wb_folio(folio_file_mapping(folio)->host, folio);
 	} while (status == 0);
 	return status;
 }
@@ -1282,9 +1284,9 @@ bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
  * the PageUptodate() flag. In this case, we will need to turn off
  * write optimisations that depend on the page contents being correct.
  */
-static bool nfs_write_pageuptodate(struct page *page, struct inode *inode,
-				   unsigned int pagelen)
+static bool nfs_folio_write_uptodate(struct folio *folio, unsigned int pagelen)
 {
+	struct inode *inode = folio_file_mapping(folio)->host;
 	struct nfs_inode *nfsi = NFS_I(inode);
 
 	if (nfs_have_delegated_attributes(inode))
@@ -1298,7 +1300,7 @@ static bool nfs_write_pageuptodate(struct page *page, struct inode *inode,
 out:
 	if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0)
 		return false;
-	return PageUptodate(page) != 0;
+	return folio_test_uptodate(folio) != 0;
 }
 
 static bool
@@ -1316,16 +1318,17 @@ is_whole_file_wrlock(struct file_lock *fl)
  * If the file is opened for synchronous writes then we can just skip the rest
  * of the checks.
  */
-static int nfs_can_extend_write(struct file *file, struct page *page,
-				struct inode *inode, unsigned int pagelen)
+static int nfs_can_extend_write(struct file *file, struct folio *folio,
+				unsigned int pagelen)
 {
-	int ret;
+	struct inode *inode = file_inode(file);
 	struct file_lock_context *flctx = inode->i_flctx;
 	struct file_lock *fl;
+	int ret;
 
 	if (file->f_flags & O_DSYNC)
 		return 0;
-	if (!nfs_write_pageuptodate(page, inode, pagelen))
+	if (!nfs_folio_write_uptodate(folio, pagelen))
 		return 0;
 	if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
 		return 1;
@@ -1357,33 +1360,33 @@ static int nfs_can_extend_write(struct file *file, struct page *page,
  * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad
  * things with a page scheduled for an RPC call (e.g. invalidate it).
  */
-int nfs_updatepage(struct file *file, struct page *page,
-		unsigned int offset, unsigned int count)
+int nfs_update_folio(struct file *file, struct folio *folio,
+		     unsigned int offset, unsigned int count)
 {
 	struct nfs_open_context *ctx = nfs_file_open_context(file);
-	struct address_space *mapping = page_file_mapping(page);
-	struct inode	*inode = mapping->host;
-	unsigned int	pagelen = nfs_page_length(page);
+	struct address_space *mapping = folio_file_mapping(folio);
+	struct inode *inode = mapping->host;
+	unsigned int pagelen = nfs_folio_length(folio);
 	int		status = 0;
 
 	nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
 
-	dprintk("NFS:       nfs_updatepage(%pD2 %d@%lld)\n",
-		file, count, (long long)(page_file_offset(page) + offset));
+	dprintk("NFS:       nfs_update_folio(%pD2 %d@%lld)\n", file, count,
+		(long long)(folio_file_pos(folio) + offset));
 
 	if (!count)
 		goto out;
 
-	if (nfs_can_extend_write(file, page, inode, pagelen)) {
+	if (nfs_can_extend_write(file, folio, pagelen)) {
 		count = max(count + offset, pagelen);
 		offset = 0;
 	}
 
-	status = nfs_writepage_setup(ctx, page, offset, count);
+	status = nfs_writepage_setup(ctx, folio, offset, count);
 	if (status < 0)
 		nfs_set_pageerror(mapping);
 out:
-	dprintk("NFS:       nfs_updatepage returns %d (isize %lld)\n",
+	dprintk("NFS:       nfs_update_folio returns %d (isize %lld)\n",
 			status, (long long)i_size_read(inode));
 	return status;
 }
@@ -1425,7 +1428,7 @@ static void nfs_redirty_request(struct nfs_page *req)
 	req->wb_nio++;
 	nfs_mark_request_dirty(req);
 	atomic_long_inc(&nfsi->redirtied_pages);
-	nfs_end_page_writeback(req);
+	nfs_page_end_writeback(req);
 	nfs_release_request(req);
 }
 
@@ -1783,18 +1786,18 @@ void nfs_retry_commit(struct list_head *page_list,
 		req = nfs_list_entry(page_list->next);
 		nfs_list_remove_request(req);
 		nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx);
-		if (!cinfo->dreq)
-			nfs_clear_page_commit(req->wb_page);
+		nfs_folio_clear_commit(nfs_page_to_folio(req));
 		nfs_unlock_and_release_request(req);
 	}
 }
 EXPORT_SYMBOL_GPL(nfs_retry_commit);
 
-static void
-nfs_commit_resched_write(struct nfs_commit_info *cinfo,
-		struct nfs_page *req)
+static void nfs_commit_resched_write(struct nfs_commit_info *cinfo,
+				     struct nfs_page *req)
 {
-	__set_page_dirty_nobuffers(req->wb_page);
+	struct folio *folio = nfs_page_to_folio(req);
+
+	filemap_dirty_folio(folio_mapping(folio), folio);
 }
 
 /*
@@ -1845,12 +1848,13 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
 	int status = data->task.tk_status;
 	struct nfs_commit_info cinfo;
 	struct nfs_server *nfss;
+	struct folio *folio;
 
 	while (!list_empty(&data->pages)) {
 		req = nfs_list_entry(data->pages.next);
 		nfs_list_remove_request(req);
-		if (req->wb_page)
-			nfs_clear_page_commit(req->wb_page);
+		folio = nfs_page_to_folio(req);
+		nfs_folio_clear_commit(folio);
 
 		dprintk("NFS:       commit (%s/%llu %d@%lld)",
 			nfs_req_openctx(req)->dentry->d_sb->s_id,
@@ -1858,10 +1862,10 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
 			req->wb_bytes,
 			(long long)req_offset(req));
 		if (status < 0) {
-			if (req->wb_page) {
+			if (folio) {
 				trace_nfs_commit_error(data->inode, req,
 						       status);
-				nfs_mapping_set_error(req->wb_page, status);
+				nfs_mapping_set_error(folio, status);
 				nfs_inode_remove_request(req);
 			}
 			dprintk_cont(", error = %d\n", status);
@@ -1872,7 +1876,7 @@ static void nfs_commit_release_pages(struct nfs_commit_data *data)
 		 * returned by the server against all stored verfs. */
 		if (nfs_write_match_verf(verf, req)) {
 			/* We have a match */
-			if (req->wb_page)
+			if (folio)
 				nfs_inode_remove_request(req);
 			dprintk_cont(" OK\n");
 			goto next;
@@ -2053,7 +2057,7 @@ int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
 
 	/* blocking call to cancel all requests and join to a single (head)
 	 * request */
-	req = nfs_lock_and_join_requests(&folio->page);
+	req = nfs_lock_and_join_requests(folio);
 
 	if (IS_ERR(req)) {
 		ret = PTR_ERR(req);
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 66b5de42f6b8..a61bfd52d551 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -569,8 +569,9 @@ extern void nfs_complete_unlink(struct dentry *dentry, struct inode *);
 extern int  nfs_congestion_kb;
 extern int  nfs_writepage(struct page *page, struct writeback_control *wbc);
 extern int  nfs_writepages(struct address_space *, struct writeback_control *);
-extern int  nfs_flush_incompatible(struct file *file, struct page *page);
-extern int  nfs_updatepage(struct file *, struct page *, unsigned int, unsigned int);
+extern int  nfs_flush_incompatible(struct file *file, struct folio *folio);
+extern int  nfs_update_folio(struct file *file, struct folio *folio,
+			     unsigned int offset, unsigned int count);
 
 /*
  * Try to write back everything synchronously (but check the
-- 
2.39.0

[PATCH 11/17] NFS: Remove unused function nfs_wb_page()

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/write.c         | 5 -----
 include/linux/nfs_fs.h | 1 -
 2 files changed, 6 deletions(-)

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 581ad66636a7..666e18e2ec3f 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2115,11 +2115,6 @@ int nfs_wb_folio(struct inode *inode, struct folio *folio)
 	return ret;
 }
 
-int nfs_wb_page(struct inode *inode, struct page *page)
-{
-	return nfs_wb_folio(inode, page_folio(page));
-}
-
 #ifdef CONFIG_MIGRATION
 int nfs_migrate_folio(struct address_space *mapping, struct folio *dst,
 		struct folio *src, enum migrate_mode mode)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index a61bfd52d551..45c44211e50e 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -580,7 +580,6 @@ extern int  nfs_update_folio(struct file *file, struct folio *folio,
 extern int nfs_sync_inode(struct inode *inode);
 extern int nfs_wb_all(struct inode *inode);
 extern int nfs_wb_folio(struct inode *inode, struct folio *folio);
-extern int nfs_wb_page(struct inode *inode, struct page *page);
 int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio);
 extern int  nfs_commit_inode(struct inode *, int);
 extern struct nfs_commit_data *nfs_commitdata_alloc(void);
-- 
2.39.0

[PATCH 12/17] NFS: Convert nfs_write_begin/end to use folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c | 75 ++++++++++++++++++++++++++++-----------------------
 1 file changed, 41 insertions(+), 34 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 9fbe27214da0..39ee7fb3f79f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -276,27 +276,28 @@ EXPORT_SYMBOL_GPL(nfs_file_fsync);
  * and that the new data won't completely replace the old data in
  * that range of the file.
  */
-static bool nfs_full_page_write(struct page *page, loff_t pos, unsigned int len)
+static bool nfs_folio_is_full_write(struct folio *folio, loff_t pos,
+				    unsigned int len)
 {
-	unsigned int pglen = nfs_page_length(page);
-	unsigned int offset = pos & (PAGE_SIZE - 1);
+	unsigned int pglen = nfs_folio_length(folio);
+	unsigned int offset = offset_in_folio(folio, pos);
 	unsigned int end = offset + len;
 
 	return !pglen || (end >= pglen && !offset);
 }
 
-static bool nfs_want_read_modify_write(struct file *file, struct page *page,
-			loff_t pos, unsigned int len)
+static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
+				       loff_t pos, unsigned int len)
 {
 	/*
 	 * Up-to-date pages, those with ongoing or full-page write
 	 * don't need read/modify/write
 	 */
-	if (PageUptodate(page) || PagePrivate(page) ||
-	    nfs_full_page_write(page, pos, len))
+	if (folio_test_uptodate(folio) || folio_test_private(folio) ||
+	    nfs_folio_is_full_write(folio, pos, len))
 		return false;
 
-	if (pnfs_ld_read_whole_page(file->f_mapping->host))
+	if (pnfs_ld_read_whole_page(file_inode(file)))
 		return true;
 	/* Open for reading too? */
 	if (file->f_mode & FMODE_READ)
@@ -304,6 +305,15 @@ static bool nfs_want_read_modify_write(struct file *file, struct page *page,
 	return false;
 }
 
+static struct folio *
+nfs_folio_grab_cache_write_begin(struct address_space *mapping, pgoff_t index)
+{
+	unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
+
+	return __filemap_get_folio(mapping, index, fgp_flags,
+				   mapping_gfp_mask(mapping));
+}
+
 /*
  * This does the "real" work of the write. We must allocate and lock the
  * page to be sent back to the generic routine, which then copies the
@@ -313,34 +323,31 @@ static bool nfs_want_read_modify_write(struct file *file, struct page *page,
  * increment the page use counts until he is done with the page.
  */
 static int nfs_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len,
-			struct page **pagep, void **fsdata)
+			   loff_t pos, unsigned len, struct page **pagep,
+			   void **fsdata)
 {
-	int ret;
-	pgoff_t index = pos >> PAGE_SHIFT;
-	struct page *page;
 	struct folio *folio;
 	int once_thru = 0;
+	int ret;
 
 	dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
 		file, mapping->host->i_ino, len, (long long) pos);
 
 start:
-	page = grab_cache_page_write_begin(mapping, index);
-	if (!page)
+	folio = nfs_folio_grab_cache_write_begin(mapping, pos >> PAGE_SHIFT);
+	if (!folio)
 		return -ENOMEM;
-	*pagep = page;
-	folio = page_folio(page);
+	*pagep = &folio->page;
 
 	ret = nfs_flush_incompatible(file, folio);
 	if (ret) {
-		unlock_page(page);
-		put_page(page);
+		folio_unlock(folio);
+		folio_put(folio);
 	} else if (!once_thru &&
-		   nfs_want_read_modify_write(file, page, pos, len)) {
+		   nfs_want_read_modify_write(file, folio, pos, len)) {
 		once_thru = 1;
 		ret = nfs_read_folio(file, folio);
-		put_page(page);
+		folio_put(folio);
 		if (!ret)
 			goto start;
 	}
@@ -348,12 +355,12 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
 }
 
 static int nfs_write_end(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned copied,
-			struct page *page, void *fsdata)
+			 loff_t pos, unsigned len, unsigned copied,
+			 struct page *page, void *fsdata)
 {
-	unsigned offset = pos & (PAGE_SIZE - 1);
 	struct nfs_open_context *ctx = nfs_file_open_context(file);
 	struct folio *folio = page_folio(page);
+	unsigned offset = offset_in_folio(folio, pos);
 	int status;
 
 	dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n",
@@ -363,26 +370,26 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 	 * Zero any uninitialised parts of the page, and then mark the page
 	 * as up to date if it turns out that we're extending the file.
 	 */
-	if (!PageUptodate(page)) {
-		unsigned pglen = nfs_page_length(page);
+	if (!folio_test_uptodate(folio)) {
+		size_t fsize = folio_size(folio);
+		unsigned pglen = nfs_folio_length(folio);
 		unsigned end = offset + copied;
 
 		if (pglen == 0) {
-			zero_user_segments(page, 0, offset,
-					end, PAGE_SIZE);
-			SetPageUptodate(page);
+			folio_zero_segments(folio, 0, offset, end, fsize);
+			folio_mark_uptodate(folio);
 		} else if (end >= pglen) {
-			zero_user_segment(page, end, PAGE_SIZE);
+			folio_zero_segment(folio, end, fsize);
 			if (offset == 0)
-				SetPageUptodate(page);
+				folio_mark_uptodate(folio);
 		} else
-			zero_user_segment(page, pglen, PAGE_SIZE);
+			folio_zero_segment(folio, pglen, fsize);
 	}
 
 	status = nfs_update_folio(file, folio, offset, copied);
 
-	unlock_page(page);
-	put_page(page);
+	folio_unlock(folio);
+	folio_put(folio);
 
 	if (status < 0)
 		return status;
-- 
2.39.0

[PATCH 13/17] NFS: Fix up nfs_vm_page_mkwrite() for folios

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 39ee7fb3f79f..563c5e0c55e8 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -556,23 +556,22 @@ const struct address_space_operations nfs_file_aops = {
  */
 static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 {
-	struct page *page = vmf->page;
 	struct file *filp = vmf->vma->vm_file;
 	struct inode *inode = file_inode(filp);
 	unsigned pagelen;
 	vm_fault_t ret = VM_FAULT_NOPAGE;
 	struct address_space *mapping;
-	struct folio *folio = page_folio(page);
+	struct folio *folio = page_folio(vmf->page);
 
 	dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
-		filp, filp->f_mapping->host->i_ino,
-		(long long)page_offset(page));
+		 filp, filp->f_mapping->host->i_ino,
+		 (long long)folio_file_pos(folio));
 
 	sb_start_pagefault(inode->i_sb);
 
 	/* make sure the cache has finished storing the page */
-	if (PageFsCache(page) &&
-	    wait_on_page_fscache_killable(vmf->page) < 0) {
+	if (folio_test_fscache(folio) &&
+	    folio_wait_fscache_killable(folio) < 0) {
 		ret = VM_FAULT_RETRY;
 		goto out;
 	}
@@ -581,14 +580,14 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 			   nfs_wait_bit_killable,
 			   TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
 
-	lock_page(page);
-	mapping = page_file_mapping(page);
+	folio_lock(folio);
+	mapping = folio_file_mapping(folio);
 	if (mapping != inode->i_mapping)
 		goto out_unlock;
 
-	wait_on_page_writeback(page);
+	folio_wait_writeback(folio);
 
-	pagelen = nfs_page_length(page);
+	pagelen = nfs_folio_length(folio);
 	if (pagelen == 0)
 		goto out_unlock;
 
@@ -599,7 +598,7 @@ static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf)
 
 	ret = VM_FAULT_SIGBUS;
 out_unlock:
-	unlock_page(page);
+	folio_unlock(folio);
 out:
 	sb_end_pagefault(inode->i_sb);
 	return ret;
-- 
2.39.0

[PATCH 14/17] NFS: Clean up O_DIRECT request allocation

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/direct.c          | 12 ++++--------
 fs/nfs/pagelist.c        | 15 +++++++++------
 include/linux/nfs_page.h |  9 +++++----
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 1707f46b1335..9a18c5a69ace 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -343,14 +343,12 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 			struct nfs_page *req;
 			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
 			/* XXX do we need to do the eof zeroing found in async_filler? */
-			req = nfs_create_request(dreq->ctx, pagevec[i],
-						 pgbase, req_len);
+			req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
+							pgbase, pos, req_len);
 			if (IS_ERR(req)) {
 				result = PTR_ERR(req);
 				break;
 			}
-			req->wb_index = pos >> PAGE_SHIFT;
-			req->wb_offset = pos & ~PAGE_MASK;
 			if (!nfs_pageio_add_request(&desc, req)) {
 				result = desc.pg_error;
 				nfs_release_request(req);
@@ -802,8 +800,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			struct nfs_page *req;
 			unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
 
-			req = nfs_create_request(dreq->ctx, pagevec[i],
-						 pgbase, req_len);
+			req = nfs_page_create_from_page(dreq->ctx, pagevec[i],
+							pgbase, pos, req_len);
 			if (IS_ERR(req)) {
 				result = PTR_ERR(req);
 				break;
@@ -816,8 +814,6 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			}
 
 			nfs_lock_request(req);
-			req->wb_index = pos >> PAGE_SHIFT;
-			req->wb_offset = pos & ~PAGE_MASK;
 			if (!nfs_pageio_add_request(&desc, req)) {
 				result = desc.pg_error;
 				nfs_unlock_and_release_request(req);
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 6706e0df1963..27fe7c07ec72 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -514,26 +514,29 @@ static void nfs_page_assign_page(struct nfs_page *req, struct page *page)
 }
 
 /**
- * nfs_create_request - Create an NFS read/write request.
+ * nfs_page_create_from_page - Create an NFS read/write request.
  * @ctx: open context to use
  * @page: page to write
- * @offset: starting offset within the page for the write
+ * @pgbase: starting offset within the page for the write
+ * @offset: file offset for the write
  * @count: number of bytes to read/write
  *
  * The page must be locked by the caller. This makes sure we never
  * create two different requests for the same page.
  * User should ensure it is safe to sleep in this function.
  */
-struct nfs_page *
-nfs_create_request(struct nfs_open_context *ctx, struct page *page,
-		   unsigned int offset, unsigned int count)
+struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
+					   struct page *page,
+					   unsigned int pgbase, loff_t offset,
+					   unsigned int count)
 {
 	struct nfs_lock_context *l_ctx = nfs_get_lock_context(ctx);
 	struct nfs_page *ret;
 
 	if (IS_ERR(l_ctx))
 		return ERR_CAST(l_ctx);
-	ret = nfs_page_create(l_ctx, offset, page_index(page), offset, count);
+	ret = nfs_page_create(l_ctx, pgbase, offset >> PAGE_SHIFT,
+			      offset_in_page(offset), count);
 	if (!IS_ERR(ret)) {
 		nfs_page_assign_page(ret, page);
 		nfs_page_group_init(ret, NULL);
diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h
index 3c71493d5cc3..a2f1ca657623 100644
--- a/include/linux/nfs_page.h
+++ b/include/linux/nfs_page.h
@@ -121,10 +121,11 @@ struct nfs_pageio_descriptor {
 
 #define NFS_WBACK_BUSY(req)	(test_bit(PG_BUSY,&(req)->wb_flags))
 
-extern	struct nfs_page *nfs_create_request(struct nfs_open_context *ctx,
-					    struct page *page,
-					    unsigned int offset,
-					    unsigned int count);
+extern struct nfs_page *nfs_page_create_from_page(struct nfs_open_context *ctx,
+						  struct page *page,
+						  unsigned int pgbase,
+						  loff_t offset,
+						  unsigned int count);
 extern struct nfs_page *nfs_page_create_from_folio(struct nfs_open_context *ctx,
 						   struct folio *folio,
 						   unsigned int offset,
-- 
2.39.0

[PATCH 15/17] NFS: fix up nfs_release_folio() to try to release the page

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

If the gfp context allows it, and we're not kswapd, then try to write
out the folio that has private data.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 563c5e0c55e8..3bed75c5250b 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -432,8 +432,13 @@ static bool nfs_release_folio(struct folio *folio, gfp_t gfp)
 	dfprintk(PAGECACHE, "NFS: release_folio(%p)\n", folio);
 
 	/* If the private flag is set, then the folio is not freeable */
-	if (folio_test_private(folio))
-		return false;
+	if (folio_test_private(folio)) {
+		if ((current_gfp_context(gfp) & GFP_KERNEL) != GFP_KERNEL ||
+		    current_is_kswapd())
+			return false;
+		if (nfs_wb_folio(folio_file_mapping(folio)->host, folio) < 0)
+			return false;
+	}
 	return nfs_fscache_release_folio(folio, gfp);
 }
 
-- 
2.39.0

[PATCH 16/17] NFS: Enable tracing of nfs_invalidate_folio() and nfs_launder_folio()

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/file.c     |  9 +++++++--
 fs/nfs/nfstrace.h | 41 +++++++++++++++++++++++++++++++++++------
 2 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 3bed75c5250b..bcade290605a 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -411,14 +411,16 @@ static int nfs_write_end(struct file *file, struct address_space *mapping,
 static void nfs_invalidate_folio(struct folio *folio, size_t offset,
 				size_t length)
 {
+	struct inode *inode = folio_file_mapping(folio)->host;
 	dfprintk(PAGECACHE, "NFS: invalidate_folio(%lu, %zu, %zu)\n",
 		 folio->index, offset, length);
 
 	if (offset != 0 || length < folio_size(folio))
 		return;
 	/* Cancel any unstarted writes on this page */
-	nfs_wb_folio_cancel(folio->mapping->host, folio);
+	nfs_wb_folio_cancel(inode, folio);
 	folio_wait_fscache(folio);
+	trace_nfs_invalidate_folio(inode, folio);
 }
 
 /*
@@ -479,12 +481,15 @@ static void nfs_check_dirty_writeback(struct folio *folio,
 static int nfs_launder_folio(struct folio *folio)
 {
 	struct inode *inode = folio->mapping->host;
+	int ret;
 
 	dfprintk(PAGECACHE, "NFS: launder_folio(%ld, %llu)\n",
 		inode->i_ino, folio_pos(folio));
 
 	folio_wait_fscache(folio);
-	return nfs_wb_folio(inode, folio);
+	ret = nfs_wb_folio(inode, folio);
+	trace_nfs_launder_folio_done(inode, folio, ret);
+	return ret;
 }
 
 static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index d83226e45335..988f2c9b607f 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -933,7 +933,7 @@ TRACE_EVENT(nfs_sillyrename_unlink,
 		)
 );
 
-TRACE_EVENT(nfs_aop_readpage,
+DECLARE_EVENT_CLASS(nfs_folio_event,
 		TP_PROTO(
 			const struct inode *inode,
 			struct folio *folio
@@ -947,6 +947,7 @@ TRACE_EVENT(nfs_aop_readpage,
 			__field(u64, fileid)
 			__field(u64, version)
 			__field(loff_t, offset)
+			__field(u32, count)
 		),
 
 		TP_fast_assign(
@@ -957,18 +958,28 @@ TRACE_EVENT(nfs_aop_readpage,
 			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
 			__entry->version = inode_peek_iversion_raw(inode);
 			__entry->offset = folio_file_pos(folio);
+			__entry->count = nfs_folio_length(folio);
 		),
 
 		TP_printk(
-			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu offset=%lld",
+			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu "
+			"offset=%lld count=%u",
 			MAJOR(__entry->dev), MINOR(__entry->dev),
 			(unsigned long long)__entry->fileid,
 			__entry->fhandle, __entry->version,
-			__entry->offset
+			__entry->offset, __entry->count
 		)
 );
 
-TRACE_EVENT(nfs_aop_readpage_done,
+#define DEFINE_NFS_FOLIO_EVENT(name) \
+	DEFINE_EVENT(nfs_folio_event, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				struct folio *folio \
+			), \
+			TP_ARGS(inode, folio))
+
+DECLARE_EVENT_CLASS(nfs_folio_event_done,
 		TP_PROTO(
 			const struct inode *inode,
 			struct folio *folio,
@@ -984,6 +995,7 @@ TRACE_EVENT(nfs_aop_readpage_done,
 			__field(u64, fileid)
 			__field(u64, version)
 			__field(loff_t, offset)
+			__field(u32, count)
 		),
 
 		TP_fast_assign(
@@ -994,18 +1006,35 @@ TRACE_EVENT(nfs_aop_readpage_done,
 			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
 			__entry->version = inode_peek_iversion_raw(inode);
 			__entry->offset = folio_file_pos(folio);
+			__entry->count = nfs_folio_length(folio);
 			__entry->ret = ret;
 		),
 
 		TP_printk(
-			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu offset=%lld ret=%d",
+			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu "
+			"offset=%lld count=%u ret=%d",
 			MAJOR(__entry->dev), MINOR(__entry->dev),
 			(unsigned long long)__entry->fileid,
 			__entry->fhandle, __entry->version,
-			__entry->offset, __entry->ret
+			__entry->offset, __entry->count, __entry->ret
 		)
 );
 
+#define DEFINE_NFS_FOLIO_EVENT_DONE(name) \
+	DEFINE_EVENT(nfs_folio_event_done, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				struct folio *folio, \
+				int ret \
+			), \
+			TP_ARGS(inode, folio, ret))
+
+DEFINE_NFS_FOLIO_EVENT(nfs_aop_readpage);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_aop_readpage_done);
+
+DEFINE_NFS_FOLIO_EVENT(nfs_invalidate_folio);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_launder_folio_done);
+
 TRACE_EVENT(nfs_aop_readahead,
 		TP_PROTO(
 			const struct inode *inode,
-- 
2.39.0

[PATCH 17/17] NFS: Improve tracing of nfs_wb_folio()

[trondmy]

From: Trond Myklebust <trond.myklebust@hammerspace.com>

Include info about which folio is being traced.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/nfstrace.h | 5 +++--
 fs/nfs/write.c    | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 988f2c9b607f..624333ac1325 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -152,8 +152,6 @@ DEFINE_NFS_INODE_EVENT(nfs_getattr_enter);
 DEFINE_NFS_INODE_EVENT_DONE(nfs_getattr_exit);
 DEFINE_NFS_INODE_EVENT(nfs_setattr_enter);
 DEFINE_NFS_INODE_EVENT_DONE(nfs_setattr_exit);
-DEFINE_NFS_INODE_EVENT(nfs_writeback_page_enter);
-DEFINE_NFS_INODE_EVENT_DONE(nfs_writeback_page_exit);
 DEFINE_NFS_INODE_EVENT(nfs_writeback_inode_enter);
 DEFINE_NFS_INODE_EVENT_DONE(nfs_writeback_inode_exit);
 DEFINE_NFS_INODE_EVENT(nfs_fsync_enter);
@@ -1032,6 +1030,9 @@ DECLARE_EVENT_CLASS(nfs_folio_event_done,
 DEFINE_NFS_FOLIO_EVENT(nfs_aop_readpage);
 DEFINE_NFS_FOLIO_EVENT_DONE(nfs_aop_readpage_done);
 
+DEFINE_NFS_FOLIO_EVENT(nfs_writeback_folio);
+DEFINE_NFS_FOLIO_EVENT_DONE(nfs_writeback_folio_done);
+
 DEFINE_NFS_FOLIO_EVENT(nfs_invalidate_folio);
 DEFINE_NFS_FOLIO_EVENT_DONE(nfs_launder_folio_done);
 
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 666e18e2ec3f..d47247411877 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -2093,7 +2093,7 @@ int nfs_wb_folio(struct inode *inode, struct folio *folio)
 	};
 	int ret;
 
-	trace_nfs_writeback_page_enter(inode);
+	trace_nfs_writeback_folio(inode, folio);
 
 	for (;;) {
 		folio_wait_writeback(folio);
@@ -2111,7 +2111,7 @@ int nfs_wb_folio(struct inode *inode, struct folio *folio)
 			goto out_error;
 	}
 out_error:
-	trace_nfs_writeback_page_exit(inode, ret);
+	trace_nfs_writeback_folio_done(inode, folio, ret);
 	return ret;
 }
 
-- 
2.39.0

Re: [PATCH 09/17] NFS: Convert the function nfs_wb_page() to use folios

[Anna Schumaker]

Hi Trond,

On Sat, Jan 7, 2023 at 12:43 PM <trondmy@kernel.org> wrote:
>
> From: Trond Myklebust <trond.myklebust@hammerspace.com>
>
> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> ---
>  fs/nfs/write.c | 35 ++++++++++++++++-------------------
>  1 file changed, 16 insertions(+), 19 deletions(-)
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index 0fbb119022d9..14f98c452595 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -2069,13 +2069,18 @@ int nfs_wb_folio_cancel(struct inode *inode, struct folio *folio)
>         return ret;
>  }
>
> -/*
> - * Write back all requests on one page - we do this before reading it.
> +/**
> + * nfs_wb_folio - Write back all requests on one page
> + * @inode: pointer to page
> + * @folio: pointer to folio
> + *
> + * Assumes that the folio has been locked by the caller, and will
> + * not unlock it.
>   */
> -int nfs_wb_page(struct inode *inode, struct page *page)
> +int nfs_wb_folio(struct inode *inode, struct folio *folio)
>  {
> -       loff_t range_start = page_file_offset(page);
> -       loff_t range_end = range_start + (loff_t)(PAGE_SIZE - 1);
> +       loff_t range_start = folio_file_pos(folio);
> +       loff_t range_end = range_start + (loff_t)folio_size(folio) - 1;
>         struct writeback_control wbc = {
>                 .sync_mode = WB_SYNC_ALL,
>                 .nr_to_write = 0,
> @@ -2087,15 +2092,15 @@ int nfs_wb_page(struct inode *inode, struct page *page)
>         trace_nfs_writeback_page_enter(inode);
>
>         for (;;) {
> -               wait_on_page_writeback(page);
> -               if (clear_page_dirty_for_io(page)) {
> -                       ret = nfs_writepage_locked(page, &wbc);
> +               folio_wait_writeback(folio);
> +               if (folio_clear_dirty_for_io(folio)) {
> +                       ret = nfs_writepage_locked(folio, &wbc);

nfs_writepage_locked() still takes a "struct page *" until the next
patch (NFS: Convert buffered writes to use folios), so I'm seeing this
when I try to compile:

fs/nfs/write.c:2097:31: error: incompatible pointer types passing
'struct folio *' to parameter of type 'struct page *'
[-Werror,-Wincompatible-pointer-types]
                        ret = nfs_writepage_locked(folio, &wbc);
                                                   ^~~~~
fs/nfs/write.c:661:46: note: passing argument to parameter 'page' here
static int nfs_writepage_locked(struct page *page,
                                             ^
1 error generated.
make[3]: *** [scripts/Makefile.build:252: fs/nfs/write.o] Error 1
make[2]: *** [scripts/Makefile.build:504: fs/nfs] Error 2
make[1]: *** [scripts/Makefile.build:504: fs] Error 2
make: *** [Makefile:2008: .] Error 2


>                         if (ret < 0)
>                                 goto out_error;
>                         continue;
>                 }
>                 ret = 0;
> -               if (!PagePrivate(page))
> +               if (!folio_test_private(folio))
>                         break;
>                 ret = nfs_commit_inode(inode, FLUSH_SYNC);
>                 if (ret < 0)
> @@ -2106,17 +2111,9 @@ int nfs_wb_page(struct inode *inode, struct page *page)
>         return ret;
>  }
>
> -/**
> - * nfs_wb_folio - Write back all requests on one page
> - * @inode: pointer to page
> - * @folio: pointer to folio
> - *
> - * Assumes that the folio has been locked by the caller, and will
> - * not unlock it.
> - */
> -int nfs_wb_folio(struct inode *inode, struct folio *folio)
> +int nfs_wb_page(struct inode *inode, struct page *page)
>  {
> -       return nfs_wb_page(inode, &folio->page);
> +       return nfs_wb_folio(inode, page_folio(page));
>  }
>
>  #ifdef CONFIG_MIGRATION
> --
> 2.39.0
>