Messages in this thread | | | Date | Tue, 18 Feb 2014 18:12:42 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH] sysfs: fix namespace refcnt leak |
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Hey,
On Mon, Feb 17, 2014 at 11:54:59AM +0800, Li Zefan wrote: > I think we have to fix kernfs in order to fix refcnt leak in sysfs > and cgroupfs. This fix is for 3.14, but it creates conflicts for > cgroup-next. > > ==================== > > As mount() and kill_sb() is not a one-to-one match, we shoudn't get > ns refcnt unconditionally in sysfs_mount(), and instead we should > get the refcnt only when kernfs_mount() allocated a new superblock.
Ugh... nasty :(
> @@ -132,6 +132,7 @@ const void *kernfs_super_ns(struct super_block *sb) > * @flags: mount flags specified for the mount > * @root: kernfs_root of the hierarchy being mounted > * @ns: optional namespace tag of the mount > + * @new: tell the caller if we allocated a new superblock
Maybe something like @new_sb_created is better?
> struct super_block *sb; > struct kernfs_super_info *info; > int error; > > + *new_sb = false;
Can we make it optional so that users who don't care about it can ignore it?
> @@ -430,9 +431,9 @@ static inline int kernfs_rename(struct kernfs_node *kn, > > static inline struct dentry * > kernfs_mount(struct file_system_type *fs_type, int flags, > - struct kernfs_root *root) > + struct kernfs_root *root, bool *new_sb) > { > - return kernfs_mount_ns(fs_type, flags, root, NULL); > + return kernfs_mount_ns(fs_type, flags, root, NULL, new_sb);
And let kernfs_mount() just use NULL for the parameter?
Thanks.
-- tejun
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