Commit 54d99381 authored by Trond Myklebust's avatar Trond Myklebust Committed by Anna Schumaker
Browse files

NFS: Convert nfs_write_begin/end to use folios 



Add a helper nfs_folio_grab_cache_write_begin() that can call
__filemap_get_folio() directly with the appropriate parameters.

Since write_begin()/write_end() take struct page arguments, just pass
the folio->page back for now.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 4cbf7694

fs/nfs/file.c

+41 −34
Original line number Diff line number Diff line
@@ -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,

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;

	}
@@ -351,9 +358,9 @@ static int nfs_write_end(struct file *file, struct address_space *mapping, 
			 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;