Document what ->pde_unload_lock actually does.
Link: http://lkml.kernel.org/r/20180103185120.GB31849@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 
        atomic_t in_use;
        atomic_t count;         /* use count */
        struct list_head pde_openers;   /* who did ->open, but not ->release */
-       spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
+       /* protects ->pde_openers and all struct pde_opener instances */
+       spinlock_t pde_unload_lock;
        struct completion *pde_unload_completion;
        const struct inode_operations *proc_iops;
        const struct file_operations *proc_fops;