2011-07-26 07:35:07

by Robin Dong

Subject: [PATCH] ext4: add action of moving index in ext4_ext_rm_idx for Punch Hole

From: Robin Dong <[email protected]>

The old function ext4_ext_rm_idx is used only for truncate case because
it just remove last index in extent-index-block. When punching hole,
it usually needed to remove "middle" index, therefore we must move indexes
which after it forward.

(I create a file with 1 depth extent tree and punch hole in the middle of it,
the last index in index-block strangly gone, so I find out this bug)

Signed-off-by: Robin Dong <[email protected]>
---
fs/ext4/extents.c | 9 +++++++--
1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 4d73e11..a25bbdc 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2101,8 +2101,6 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
/*
* ext4_ext_rm_idx:
* removes index from the index block.
- * It's used in truncate case only, thus all requests are for
- * last index in the block only.
*/
static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
@@ -2120,6 +2118,13 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
err = ext4_ext_get_access(handle, inode, path);
if (err)
return err;
+
+ if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
+ int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
+ len *= sizeof(struct ext4_extent_idx);
+ memmove(path->p_idx, path->p_idx + 1, len);
+ }
+
le16_add_cpu(&path->p_hdr->eh_entries, -1);
err = ext4_ext_dirty(handle, inode, path);
if (err)
--
1.7.3.2

2011-07-28 01:33:09

by Theodore Ts'o

Subject: Re: [PATCH] ext4: add action of moving index in ext4_ext_rm_idx for Punch Hole

On Tue, Jul 26, 2011 at 03:34:59PM +0800, Robin Dong wrote:
> From: Robin Dong <[email protected]>
>
> The old function ext4_ext_rm_idx is used only for truncate case because
> it just remove last index in extent-index-block. When punching hole,
> it usually needed to remove "middle" index, therefore we must move indexes
> which after it forward.
>
> (I create a file with 1 depth extent tree and punch hole in the middle of it,
> the last index in index-block strangly gone, so I find out this bug)
>
> Signed-off-by: Robin Dong <[email protected]>

Thanks, added to the ext4 tree.

- Ted