ext4: pass the inode to ext4_mpage_readpages

This function now only uses the mapping argument to look up the inode, and
both callers already have the inode, so just pass the inode instead of the
mapping.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-22-willy@infradead.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ext4/ext4.h

@@ -3317,7 +3317,7 @@ static inline void ext4_set_de_type(struct super_block *sb,
 }
 
 /* readpages.c */
-extern int ext4_mpage_readpages(struct address_space *mapping,
+extern int ext4_mpage_readpages(struct inode *inode,
 		struct readahead_control *rac, struct page *page);
 extern int __init ext4_init_post_read_processing(void);
 extern void ext4_exit_post_read_processing(void);

fs/ext4/inode.c

@@ -3224,7 +3224,7 @@ static int ext4_readpage(struct file *file, struct page *page)
 		ret = ext4_readpage_inline(inode, page);
 
 	if (ret == -EAGAIN)
-		return ext4_mpage_readpages(page->mapping, NULL, page);
+		return ext4_mpage_readpages(inode, NULL, page);
 
 	return ret;
 }
@@ -3237,7 +3237,7 @@ static void ext4_readahead(struct readahead_control *rac)
 	if (ext4_has_inline_data(inode))
 		return;
 
-	ext4_mpage_readpages(rac->mapping, rac, NULL);
+	ext4_mpage_readpages(inode, rac, NULL);
 }
 
 static void ext4_invalidatepage(struct page *page, unsigned int offset,

fs/ext4/readpage.c

@@ -221,13 +221,12 @@ static inline loff_t ext4_readpage_limit(struct inode *inode)
 	return i_size_read(inode);
 }
 
-int ext4_mpage_readpages(struct address_space *mapping,
+int ext4_mpage_readpages(struct inode *inode,
 		struct readahead_control *rac, struct page *page)
 {
 	struct bio *bio = NULL;
 	sector_t last_block_in_bio = 0;
 
-	struct inode *inode = mapping->host;
 	const unsigned blkbits = inode->i_blkbits;
 	const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
 	const unsigned blocksize = 1 << blkbits;