1 files changed, 54 insertions, 27 deletions

diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 44e9de51eedf..5f23ee599889 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -198,13 +198,11 @@ void touch_buffer(struct buffer_head *bh);
 void folio_set_bh(struct buffer_head *bh, struct folio *folio,
 		  unsigned long offset);
 struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size,
-					bool retry);
+					gfp_t gfp);
 struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
 		bool retry);
-void create_empty_buffers(struct page *, unsigned long,
-			unsigned long b_state);
-void folio_create_empty_buffers(struct folio *folio, unsigned long blocksize,
-				unsigned long b_state);
+struct buffer_head *create_empty_buffers(struct folio *folio,
+		unsigned long blocksize, unsigned long b_state);
 void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
 void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
 void end_buffer_async_write(struct buffer_head *bh, int uptodate);
@@ -227,8 +225,8 @@ void __wait_on_buffer(struct buffer_head *);
 wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
 struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
 			unsigned size);
-struct buffer_head *__getblk_gfp(struct block_device *bdev, sector_t block,
-				  unsigned size, gfp_t gfp);
+struct buffer_head *bdev_getblk(struct block_device *bdev, sector_t block,
+		unsigned size, gfp_t gfp);
 void __brelse(struct buffer_head *);
 void __bforget(struct buffer_head *);
 void __breadahead(struct block_device *, sector_t block, unsigned int size);
@@ -338,17 +336,38 @@ sb_breadahead(struct super_block *sb, sector_t block)
 	__breadahead(sb->s_bdev, block, sb->s_blocksize);
 }
 
-static inline struct buffer_head *
-sb_getblk(struct super_block *sb, sector_t block)
+static inline struct buffer_head *getblk_unmovable(struct block_device *bdev,
+		sector_t block, unsigned size)
 {
-	return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE);
+	gfp_t gfp;
+
+	gfp = mapping_gfp_constraint(bdev->bd_inode->i_mapping, ~__GFP_FS);
+	gfp |= __GFP_NOFAIL;
+
+	return bdev_getblk(bdev, block, size, gfp);
 }
 
+static inline struct buffer_head *__getblk(struct block_device *bdev,
+		sector_t block, unsigned size)
+{
+	gfp_t gfp;
 
-static inline struct buffer_head *
-sb_getblk_gfp(struct super_block *sb, sector_t block, gfp_t gfp)
+	gfp = mapping_gfp_constraint(bdev->bd_inode->i_mapping, ~__GFP_FS);
+	gfp |= __GFP_MOVABLE | __GFP_NOFAIL;
+
+	return bdev_getblk(bdev, block, size, gfp);
+}
+
+static inline struct buffer_head *sb_getblk(struct super_block *sb,
+		sector_t block)
 {
-	return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, gfp);
+	return __getblk(sb->s_bdev, block, sb->s_blocksize);
+}
+
+static inline struct buffer_head *sb_getblk_gfp(struct super_block *sb,
+		sector_t block, gfp_t gfp)
+{
+	return bdev_getblk(sb->s_bdev, block, sb->s_blocksize, gfp);
 }
 
 static inline struct buffer_head *
@@ -385,20 +404,6 @@ static inline void lock_buffer(struct buffer_head *bh)
 		__lock_buffer(bh);
 }
 
-static inline struct buffer_head *getblk_unmovable(struct block_device *bdev,
-						   sector_t block,
-						   unsigned size)
-{
-	return __getblk_gfp(bdev, block, size, 0);
-}
-
-static inline struct buffer_head *__getblk(struct block_device *bdev,
-					   sector_t block,
-					   unsigned size)
-{
-	return __getblk_gfp(bdev, block, size, __GFP_MOVABLE);
-}
-
 static inline void bh_readahead(struct buffer_head *bh, blk_opf_t op_flags)
 {
 	if (!buffer_uptodate(bh) && trylock_buffer(bh)) {
@@ -450,6 +455,28 @@ __bread(struct block_device *bdev, sector_t block, unsigned size)
 	return __bread_gfp(bdev, block, size, __GFP_MOVABLE);
 }
 
+/**
+ * get_nth_bh - Get a reference on the n'th buffer after this one.
+ * @bh: The buffer to start counting from.
+ * @count: How many buffers to skip.
+ *
+ * This is primarily useful for finding the nth buffer in a folio; in
+ * that case you pass the head buffer and the byte offset in the folio
+ * divided by the block size.  It can be used for other purposes, but
+ * it will wrap at the end of the folio rather than returning NULL or
+ * proceeding to the next folio for you.
+ *
+ * Return: The requested buffer with an elevated refcount.
+ */
+static inline __must_check
+struct buffer_head *get_nth_bh(struct buffer_head *bh, unsigned int count)
+{
+	while (count--)
+		bh = bh->b_this_page;
+	get_bh(bh);
+	return bh;
+}
+
 bool block_dirty_folio(struct address_space *mapping, struct folio *folio);
 
 #ifdef CONFIG_BUFFER_HEAD