We have to update extent's state after first ext4_split_extent_at otherwise this result
in following trace:
->ext4_ext_handle_uninitialized_extents (ex=[1000:20:uninit], lblock 1000, max_blocks 10)
->ext4_split_extent_at(ex=[1000,128], lblk 10010) /// First split
->ext4_ext_split() -> ENOSPC
->ext4_ext_zeroout
->ext4_ext_dirty -> ex=[1000:20:init]
->ext4_split_extent_at(ex=[1000,128], lblk 10000) /// Second split
if(split == ee_block)
if (split_flag & EXT4_EXT_MARK_UNINIT2)
ext4_ext_mark_uninitialized(ex); ex=[1000:20:uninit] /// The bug!
->ext4_ext_dirty ->ex=[1000:20:uninit]
At the end ext4_convert_unwritten_extents_endio() will findout large uninitialized
extent.
TESTCASE: https://github.com/dmonakhov/xfstests/commit/1a1c4f337d4d198803436c63a56625b1a78d8a5e
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/ext4/extents.c | 14 ++++++++++----
1 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 97cac01..7a3f679 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3091,18 +3091,24 @@ static int ext4_split_extent(handle_t *handle,
if (err)
goto out;
}
-
+ /* Update path is required because previous ext4_split_extent_at() may
+ * result in split of original leaf or extent zeroout.
+ */
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode, map->m_lblk, path);
if (IS_ERR(path))
return PTR_ERR(path);
+ depth = ext_depth(inode);
+ ex = path[depth].p_ext;
+ uninitialized = ext4_ext_is_uninitialized(ex);
if (map->m_lblk >= ee_block) {
split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
- if (uninitialized)
+ if (uninitialized) {
split_flag1 |= EXT4_EXT_MARK_UNINIT1;
- if (split_flag & EXT4_EXT_MARK_UNINIT2)
- split_flag1 |= EXT4_EXT_MARK_UNINIT2;
+ if (split_flag & EXT4_EXT_MARK_UNINIT2)
+ split_flag1 |= EXT4_EXT_MARK_UNINIT2;
+ }
err = ext4_split_extent_at(handle, inode, path,
map->m_lblk, split_flag1, flags);
if (err)
--
1.7.1
--
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