[PATCH 4.4 43/74] reiserfs: dont preallocate blocks for extended attributes

From: Greg Kroah-Hartman
Date: Mon Jan 29 2018 - 15:31:50 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jeff Mahoney <jeffm@xxxxxxxx>

commit 54930dfeb46e978b447af0fb8ab4e181c1bf9d7a upstream.

Most extended attributes will fit in a single block. More importantly,
we drop the reference to the inode while holding the transaction open
so the preallocated blocks aren't released. As a result, the inode
may be evicted before it's removed from the transaction's prealloc list
which can cause memory corruption.

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/reiserfs/bitmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -1136,7 +1136,7 @@ static int determine_prealloc_size(reise
hint->prealloc_size = 0;

if (!hint->formatted_node && hint->preallocate) {
- if (S_ISREG(hint->inode->i_mode)
+ if (S_ISREG(hint->inode->i_mode) && !IS_PRIVATE(hint->inode)
&& hint->inode->i_size >=
REISERFS_SB(hint->th->t_super)->s_alloc_options.
preallocmin * hint->inode->i_sb->s_blocksize)