ext4: simplify list handling in ext4_do_flush_completed_IO()

The function splices i_completed_io_list to its private list
first.  From that moment on we don't need any lock for working with
io_end structures because all io_end structure on the list are only
our own. So we can remove the other two lists in the function and free
io_end immediately after we are done with it.

CC: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Jan Kara 2013-01-28 09:49:15 -05:00 committed by Theodore Ts'o
parent 84c17543ab
commit 002bd7fa3a
1 changed files with 1 additions and 17 deletions

View File

@ -160,14 +160,11 @@ void ext4_add_complete_io(ext4_io_end_t *io_end)
static int ext4_do_flush_completed_IO(struct inode *inode)
{
ext4_io_end_t *io;
struct list_head unwritten, complete, to_free;
struct list_head unwritten;
unsigned long flags;
struct ext4_inode_info *ei = EXT4_I(inode);
int err, ret = 0;
INIT_LIST_HEAD(&complete);
INIT_LIST_HEAD(&to_free);
spin_lock_irqsave(&ei->i_completed_io_lock, flags);
dump_completed_IO(inode);
list_replace_init(&ei->i_completed_io_list, &unwritten);
@ -181,20 +178,7 @@ static int ext4_do_flush_completed_IO(struct inode *inode)
err = ext4_end_io(io);
if (unlikely(!ret && err))
ret = err;
list_add_tail(&io->list, &complete);
}
spin_lock_irqsave(&ei->i_completed_io_lock, flags);
while (!list_empty(&complete)) {
io = list_entry(complete.next, ext4_io_end_t, list);
io->flag &= ~EXT4_IO_END_UNWRITTEN;
list_move(&io->list, &to_free);
}
spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
while (!list_empty(&to_free)) {
io = list_entry(to_free.next, ext4_io_end_t, list);
list_del_init(&io->list);
ext4_free_io_end(io);
}
return ret;