2011-05-10 18:13:08

by Eric Gouriou

Subject: [PATCH] ext4: fix unbalanced up_write() in ext4_ext_truncate() error path

ext4_ext_truncate() should not invoke up_write(&EXT4_I(inode)->i_data_sem)
when ext4_orphan_add() returns an error, as it hasn't performed a
down_write() yet. This trivial patch fixes this by moving the up_write()
invocation above the out_stop label.

Signed-off-by: Eric Gouriou <[email protected]>
---
fs/ext4/extents.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e363f21..ae3c9e6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3443,8 +3443,9 @@ void ext4_ext_truncate(struct inode *inode)
if (IS_SYNC(inode))
ext4_handle_sync(handle);

-out_stop:
up_write(&EXT4_I(inode)->i_data_sem);
+
+out_stop:
/*
* If this was a simple ftruncate() and the file will remain alive,
* then we need to clear up the orphan record which we created above.
--
1.7.3.1

2011-05-23 01:43:06

by Theodore Ts'o

Subject: Re: [PATCH] ext4: fix unbalanced up_write() in ext4_ext_truncate() error path

On Tue, May 10, 2011 at 11:12:57AM -0700, Eric Gouriou wrote:
> ext4_ext_truncate() should not invoke up_write(&EXT4_I(inode)->i_data_sem)
> when ext4_orphan_add() returns an error, as it hasn't performed a
> down_write() yet. This trivial patch fixes this by moving the up_write()
> invocation above the out_stop label.
>
> Signed-off-by: Eric Gouriou <[email protected]>

Thanks, applied to the ext4 tree!

- Ted