iomap: Add flags parameter to iomap_page_create()

Add the kiocb flags parameter to the function iomap_page_create().
Depending on the value of the flags parameter it enables different gfp
flags.

No intended functional changes in this patch.
Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-5-shr@fb.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/iomap/buffered-io.c

@@ -44,20 +44,28 @@ static inline struct iomap_page *to_iomap_page(struct folio *folio)
 static struct bio_set iomap_ioend_bioset;
 
 static struct iomap_page *
-iomap_page_create(struct inode *inode, struct folio *folio)
+iomap_page_create(struct inode *inode, struct folio *folio, unsigned int flags)
 {
 	struct iomap_page *iop = to_iomap_page(folio);
 	unsigned int nr_blocks = i_blocks_per_folio(inode, folio);
+	gfp_t gfp;
 
 	if (iop || nr_blocks <= 1)
 		return iop;
 
+	if (flags & IOMAP_NOWAIT)
+		gfp = GFP_NOWAIT;
+	else
+		gfp = GFP_NOFS | __GFP_NOFAIL;
+
 	iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)),
-			GFP_NOFS | __GFP_NOFAIL);
-	spin_lock_init(&iop->uptodate_lock);
-	if (folio_test_uptodate(folio))
-		bitmap_fill(iop->uptodate, nr_blocks);
-	folio_attach_private(folio, iop);
+		      gfp);
+	if (iop) {
+		spin_lock_init(&iop->uptodate_lock);
+		if (folio_test_uptodate(folio))
+			bitmap_fill(iop->uptodate, nr_blocks);
+		folio_attach_private(folio, iop);
+	}
 	return iop;
 }
 
@@ -226,7 +234,7 @@ static int iomap_read_inline_data(const struct iomap_iter *iter,
 	if (WARN_ON_ONCE(size > iomap->length))
 		return -EIO;
 	if (offset > 0)
-		iop = iomap_page_create(iter->inode, folio);
+		iop = iomap_page_create(iter->inode, folio, iter->flags);
 	else
 		iop = to_iomap_page(folio);
 
@@ -264,7 +272,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
 		return iomap_read_inline_data(iter, folio);
 
 	/* zero post-eof blocks as the page may be mapped */
-	iop = iomap_page_create(iter->inode, folio);
+	iop = iomap_page_create(iter->inode, folio, iter->flags);
 	iomap_adjust_read_range(iter->inode, folio, &pos, length, &poff, &plen);
 	if (plen == 0)
 		goto done;
@@ -547,7 +555,7 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
 		size_t len, struct folio *folio)
 {
 	const struct iomap *srcmap = iomap_iter_srcmap(iter);
-	struct iomap_page *iop = iomap_page_create(iter->inode, folio);
+	struct iomap_page *iop;
 	loff_t block_size = i_blocksize(iter->inode);
 	loff_t block_start = round_down(pos, block_size);
 	loff_t block_end = round_up(pos + len, block_size);
@@ -558,6 +566,8 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
 		return 0;
 	folio_clear_error(folio);
 
+	iop = iomap_page_create(iter->inode, folio, iter->flags);
+
 	do {
 		iomap_adjust_read_range(iter->inode, folio, &block_start,
 				block_end - block_start, &poff, &plen);
@@ -1329,7 +1339,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
 		struct writeback_control *wbc, struct inode *inode,
 		struct folio *folio, u64 end_pos)
 {
-	struct iomap_page *iop = iomap_page_create(inode, folio);
+	struct iomap_page *iop = iomap_page_create(inode, folio, 0);
 	struct iomap_ioend *ioend, *next;
 	unsigned len = i_blocksize(inode);
 	unsigned nblocks = i_blocks_per_folio(inode, folio);