From: Christoph Hellwig <hch@lst.de>
Date: Tue, 10 Aug 2021 18:33:07 -0700
Subject: [PATCH] iomap: fix the iomap_readpage_actor return value for inline
 data
Git-commit: 740499c78408f75c4e76feac848177cb0d0ccf4f
Patch-mainline: v5.15-rc1
References: jsc#PED-1183

The actor should never return a larger value than the length that was
passed in.  The current code handles this gracefully, but the opcoming
iter model will be more picky.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 fs/iomap/buffered-io.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 0273aede8b1d..8418dffe8acf 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -205,7 +205,7 @@ struct iomap_readpage_ctx {
 	struct readahead_control *rac;
 };
 
-static int iomap_read_inline_data(struct inode *inode, struct page *page,
+static loff_t iomap_read_inline_data(struct inode *inode, struct page *page,
 		const struct iomap *iomap)
 {
 	size_t size = i_size_read(inode) - iomap->offset;
@@ -253,7 +253,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 	sector_t sector;
 
 	if (iomap->type == IOMAP_INLINE)
-		return iomap_read_inline_data(inode, page, iomap);
+		return min(iomap_read_inline_data(inode, page, iomap), length);
 
 	/* zero post-eof blocks as the page may be mapped */
 	iop = iomap_page_create(inode, page);
-- 
2.35.3