[PATCH 1/1] ext4: Fix bs < ps issue reported with dioread_nolock mount opt

[Ritesh Harjani <riteshh@linux.ibm.com>]

left shifting m_lblk by blkbits was causing value overflow and hence
it was not able to convert unwritten to written extent.
So, make sure we typecast it to loff_t before do left shift operation.
Also in func ext4_convert_unwritten_io_end_vec(), make sure to initialize
ret variable to avoid accidentally returning an uninitialized ret.

This patch fixes the issue reported in ext4 for bs < ps with
dioread_nolock mount option.

Fixes: c8cc88163f40df39e50c ("ext4: Add support for blocksize < pagesize in dioread_nolock")
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
---
 fs/ext4/extents.c | 2 +-
 fs/ext4/inode.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a0481582187a..32d610cc896d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4769,7 +4769,7 @@ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
 
 int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
 {
-	int ret, err = 0;
+	int ret = 0, err = 0;
 	struct ext4_io_end_vec *io_end_vec;
 
 	/*
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index bf596467c234..3021235deaa1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2254,7 +2254,7 @@ static int mpage_process_page(struct mpage_da_data *mpd, struct page *page,
 					err = PTR_ERR(io_end_vec);
 					goto out;
 				}
-				io_end_vec->offset = mpd->map.m_lblk << blkbits;
+				io_end_vec->offset = (loff_t)mpd->map.m_lblk << blkbits;
 			}
 			*map_bh = true;
 			goto out;
-- 
2.26.2