Hello Jan, > Hi Wang, > > On Thu, March 28, 2013 at 11:53 (+0100), Wang Shilong wrote: >> From: Wang Shilong <wangsl-f...@cn.fujitsu.com> >> >> 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?
I have explained it clearly in [PATCH V2 0/6]. http://marc.info/?l=linux-btrfs&m=136446806332680&w=2 > >> Signed-off-by: Wang Shilong <wangsl-f...@cn.fujitsu.com> >> Reviewed-by: Miao Xie <mi...@cn.fujitsu.com> >> --- >> 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. It is reasonable, but i will move the mutex lock to group.c to avoid serialize operations. > > 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 for correcting me~. Thanks, Wang > > Thanks, > -Jan > >> [snip] -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
