Hi Wang, On Thu, March 28, 2013 at 11:53 (+0100), Wang Shilong wrote: > From: Wang Shilong <[email protected]> > > This patch introduces mutex lock 'quota_lock', and makes > all the user change for quota protected by quota_lock.
Can you please add a few lines why this lock is needed? I.e., which ioctls fail without that kind of synchronization? > Signed-off-by: Wang Shilong <[email protected]> > Reviewed-by: Miao Xie <[email protected]> > --- > fs/btrfs/ctree.h | 3 +++ > fs/btrfs/disk-io.c | 1 + > fs/btrfs/ioctl.c | 16 ++++++++++++---- > 3 files changed, 16 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index 6e81860..a11a8ed 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -1584,6 +1584,9 @@ struct btrfs_fs_info { > struct rb_root qgroup_tree; > spinlock_t qgroup_lock; > > + /* protect user change operations for quota */ > + struct mutex quota_lock; Having fs_info->qgroup_lock and fs_info->quota_lock going to be a major source of confusion. I'd call the new one qgroup_ioctl_lock or ioctl_qgroup_lock instead. Furthermore, the term "quota" was intentionally left unused to leave room for other quota implementations later (user quota). And, please, use --thread with git send-email for related patches to get correct headers. Thanks, -Jan > [snip] -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
