From: Zheng Liu <wenqing.lz@xxxxxxxxxx>
We always assume that the return value of ext4_ext_map_blocks is equal
to map->m_len but when we try to convert an unwritten extent 'm_len'
value will break this assumption. It is harmless until we use status
tree as a extent cache because we need to update status tree according
to 'm_len' value.
Meanwhile this commit marks EXT4_MAP_MAPPED flag after unwritten extent
conversion. It shouldn't cause a bug because we update status tree
according to checking EXT4_MAP_UNWRITTEN flag. But it should be fixed.
After applied this commit, the following error message from self-testing
infrastructure disappears.
...
kernel: ES len assertation failed for inode: 230 retval 1 !=
map->m_len 3 in ext4_map_blocks (allocation)
...
Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/ext4/extents.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 25c86aa..110e85a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3650,6 +3650,10 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
path, map->m_len);
} else
err = ret;
+ map->m_flags |= EXT4_MAP_MAPPED;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
goto out2;
}
/* buffered IO case */
--
1.7.12.rc2.18.g61b472e
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