ext4: fix bs < ps issue reported with dioread_nolock mount opt

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")
Cc: stable@kernel.org
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/af902b5db99e8b73980c795d84ad7bb417487e76.1602168865.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 2baf0de..e46f338 100644 (file)
--- 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 2ac294f..09096fe 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2258,7 +2258,7 @@ 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;