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authorZheng Liu <wenqing.lz@taobao.com>2013-03-10 21:20:23 -0400
committerBen Hutchings <ben@decadent.org.uk>2013-03-27 02:41:11 +0000
commitb875372a397f6df49af30c4db431a4a699cf40c1 (patch)
treed0276c1306f03a508e2ac40e23c0fe124503f3d3
parentb47085aa6c21a8d62b654c0369e615eb7bf167da (diff)
ext4: fix the wrong number of the allocated blocks in ext4_split_extent()
commit 3a2256702e47f68f921dfad41b1764d05c572329 upstream. This commit fixes a wrong return value of the number of the allocated blocks in ext4_split_extent. When the length of blocks we want to allocate is greater than the length of the current extent, we return a wrong number. Let's see what happens in the following case when we call ext4_split_extent(). map: [48, 72] ex: [32, 64, u] 'ex' will be split into two parts: ex1: [32, 47, u] ex2: [48, 64, w] 'map->m_len' is returned from this function, and the value is 24. But the real length is 16. So it should be fixed. Meanwhile in this commit we use right length of the allocated blocks when get_reserved_cluster_alloc in ext4_ext_handle_uninitialized_extents is called. Signed-off-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--fs/ext4/extents.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index b48e0dc2c22d..ce0bc25f45d0 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2960,6 +2960,7 @@ static int ext4_split_extent(handle_t *handle,
int err = 0;
int uninitialized;
int split_flag1, flags1;
+ int allocated = map->m_len;
depth = ext_depth(inode);
ex = path[depth].p_ext;
@@ -2979,6 +2980,8 @@ static int ext4_split_extent(handle_t *handle,
map->m_lblk + map->m_len, split_flag1, flags1);
if (err)
goto out;
+ } else {
+ allocated = ee_len - (map->m_lblk - ee_block);
}
ext4_ext_drop_refs(path);
@@ -3001,7 +3004,7 @@ static int ext4_split_extent(handle_t *handle,
ext4_ext_show_leaf(inode, path);
out:
- return err ? err : map->m_len;
+ return err ? err : allocated;
}
#define EXT4_EXT_ZERO_LEN 7
@@ -3663,6 +3666,7 @@ out:
allocated - map->m_len);
allocated = map->m_len;
}
+ map->m_len = allocated;
/*
* If we have done fallocate with the offset that is already