ext4: fix wrong size computation in ext4_mb_normalize_request()

As the member fe_len defined in struct ext4_free_extent is expressed as
number of clusters, the variable "size" computation is wrong, we need to
first translate fe_len to block number, then to bytes.

Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 18a16191249a..0e9466f9e767 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -3075,8 +3075,9 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
                                                         (23 - bsbits)) << 23;
                 size = 8 * 1024 * 1024;
         } else {
-                start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
-                size      = ac->ac_o_ex.fe_len << bsbits;
+                start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
+                size      = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
+                                              ac->ac_o_ex.fe_len) << bsbits;
         }
         size = size >> bsbits;
         start = start_off >> bsbits;