ext4: update extent status tree after an extent is zeroed out

When we try to split an extent, this extent could be zeroed out and mark
as initialized.  But we don't know this in ext4_map_blocks because it
only returns a length of allocated extent.  Meanwhile we will mark this
extent as uninitialized because we only check m_flags.

This commit update extent status tree when we try to split an unwritten
extent.  We don't need to worry about the status of this extent because
we always mark it as initialized.

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>

1 files changed, 31 insertions, 4 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 110e85a1f82a..7e37018d1753 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2925,7 +2925,7 @@ static int ext4_split_extent_at(handle_t *handle,
 {
         ext4_fsblk_t newblock;
         ext4_lblk_t ee_block;
-        struct ext4_extent *ex, newex, orig_ex;
+        struct ext4_extent *ex, newex, orig_ex, zero_ex;
         struct ext4_extent *ex2 = NULL;
         unsigned int ee_len, depth;
         int err = 0;
@@ -2996,12 +2996,26 @@ static int ext4_split_extent_at(handle_t *handle,
         err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
         if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
                 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
-                        if (split_flag & EXT4_EXT_DATA_VALID1)
+                        if (split_flag & EXT4_EXT_DATA_VALID1) {
                                 err = ext4_ext_zeroout(inode, ex2);
-                        else
+                                zero_ex.ee_block = ex2->ee_block;
+                                zero_ex.ee_len = ext4_ext_get_actual_len(ex2);
+                                ext4_ext_store_pblock(&zero_ex,
+                                                      ext4_ext_pblock(ex2));
+                        } else {
                                 err = ext4_ext_zeroout(inode, ex);
-                } else
+                                zero_ex.ee_block = ex->ee_block;
+                                zero_ex.ee_len = ext4_ext_get_actual_len(ex);
+                                ext4_ext_store_pblock(&zero_ex,
+                                                      ext4_ext_pblock(ex));
+                        }
+                } else {
                         err = ext4_ext_zeroout(inode, &orig_ex);
+                        zero_ex.ee_block = orig_ex.ee_block;
+                        zero_ex.ee_len = ext4_ext_get_actual_len(&orig_ex);
+                        ext4_ext_store_pblock(&zero_ex,
+                                              ext4_ext_pblock(&orig_ex));
+                }
 
                 if (err)
                         goto fix_extent_len;
@@ -3009,6 +3023,12 @@ static int ext4_split_extent_at(handle_t *handle,
                 ex->ee_len = cpu_to_le16(ee_len);
                 ext4_ext_try_to_merge(handle, inode, path, ex);
                 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+                if (err)
+                        goto fix_extent_len;
+
+                /* update extent status tree */
+                err = ext4_es_zeroout(inode, &zero_ex);
+
                 goto out;
         } else if (err)
                 goto fix_extent_len;
@@ -3150,6 +3170,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
         ee_block = le32_to_cpu(ex->ee_block);
         ee_len = ext4_ext_get_actual_len(ex);
         allocated = ee_len - (map->m_lblk - ee_block);
+        zero_ex.ee_len = 0;
 
         trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
 
@@ -3247,6 +3268,9 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                 err = ext4_ext_zeroout(inode, ex);
                 if (err)
                         goto out;
+                zero_ex.ee_block = ex->ee_block;
+                zero_ex.ee_len = ext4_ext_get_actual_len(ex);
+                ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
 
                 err = ext4_ext_get_access(handle, inode, path + depth);
                 if (err)
@@ -3305,6 +3329,9 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
                 err = allocated;
 
 out:
+        /* If we have gotten a failure, don't zero out status tree */
+        if (!err)
+                err = ext4_es_zeroout(inode, &zero_ex);
         return err ? err : allocated;
 }