[PATCH] ufs: truncate should allocate block for last byte

This patch fixes buggy behaviour of UFS
in such kind of scenario:
open(, O_TRUNC...)
ftruncate(, 1024)
ftruncate(, 0)

Such a scenario causes ufs_panic and remount read-only.  This happen
because of according to specification UFS should always allocate block for
last byte, and many parts of our implementation rely on this, but
`ufs_truncate' doesn't care about this.

To make possible return error code and to know about old size, this patch
removes `truncate' from ufs inode_operations and uses `setattr' method to
call ufs_truncate.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 488b5ff..e7c8615 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -843,14 +843,17 @@ int ufs_sync_inode (struct inode *inode)
 
 void ufs_delete_inode (struct inode * inode)
 {
+	loff_t old_i_size;
+
 	truncate_inode_pages(&inode->i_data, 0);
 	/*UFS_I(inode)->i_dtime = CURRENT_TIME;*/
 	lock_kernel();
 	mark_inode_dirty(inode);
 	ufs_update_inode(inode, IS_SYNC(inode));
+	old_i_size = inode->i_size;
 	inode->i_size = 0;
-	if (inode->i_blocks)
-		ufs_truncate (inode);
+	if (inode->i_blocks && ufs_truncate(inode, old_i_size))
+		ufs_warning(inode->i_sb, __FUNCTION__, "ufs_truncate failed\n");
 	ufs_free_inode (inode);
 	unlock_kernel();
 }