ext4: call bdev_getblk() from sb_getblk_gfp()

Most of the callers of sb_getblk_gfp() already assumed that they were
passing the entire GFP flags to use.  Fix up the two callers that didn't,
and remove the __GFP_NOFAIL from them since they both appear to correctly
handle failure.

Link: https://lkml.kernel.org/r/20230914150011.843330-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Hui Zhu <teawater@antgroup.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Matthew Wilcox (Oracle)

fs/ext4/super.c

@@ -244,13 +244,19 @@ static struct buffer_head *__ext4_sb_bread_gfp(struct super_block *sb,
 struct buffer_head *ext4_sb_bread(struct super_block *sb, sector_t block,
 				   blk_opf_t op_flags)
 {
-	return __ext4_sb_bread_gfp(sb, block, op_flags, __GFP_MOVABLE);
+	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_inode->i_mapping,
+			~__GFP_FS) | __GFP_MOVABLE;
+
+	return __ext4_sb_bread_gfp(sb, block, op_flags, gfp);
 }
 
 struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
 					    sector_t block)
 {
-	return __ext4_sb_bread_gfp(sb, block, 0, 0);
+	gfp_t gfp = mapping_gfp_constraint(sb->s_bdev->bd_inode->i_mapping,
+			~__GFP_FS);
+
+	return __ext4_sb_bread_gfp(sb, block, 0, gfp);
 }
 
 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)

include/linux/buffer_head.h

@@ -368,10 +368,10 @@ static inline struct buffer_head *sb_getblk(struct super_block *sb,
 	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)
+static inline struct buffer_head *sb_getblk_gfp(struct super_block *sb,
+		sector_t block, gfp_t gfp)
 {
-	return __getblk_gfp(sb->s_bdev, block, sb->s_blocksize, gfp);
+	return bdev_getblk(sb->s_bdev, block, sb->s_blocksize, gfp);
 }
 
 static inline struct buffer_head *