procfs: Push down the bkl from ioctl

Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.

v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
    handlers surgery.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>

1 files changed, 10 insertions, 4 deletions

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 39bddba53ba1..95690a8a4d80 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1331,12 +1331,18 @@ static unsigned int cache_poll_procfs(struct file *filp, poll_table *wait)
         return cache_poll(filp, wait, cd);
 }
 
-static int cache_ioctl_procfs(struct inode *inode, struct file *filp,
-                              unsigned int cmd, unsigned long arg)
+static long cache_ioctl_procfs(struct file *filp,
+                               unsigned int cmd, unsigned long arg)
 {
+        long ret;
+        struct inode *inode = filp->f_path.dentry->d_inode;
         struct cache_detail *cd = PDE(inode)->data;
 
-        return cache_ioctl(inode, filp, cmd, arg, cd);
+        lock_kernel();
+        ret = cache_ioctl(inode, filp, cmd, arg, cd);
+        unlock_kernel();
+
+        return ret;
 }
 
 static int cache_open_procfs(struct inode *inode, struct file *filp)
@@ -1359,7 +1365,7 @@ static const struct file_operations cache_file_operations_procfs = {
         .read           = cache_read_procfs,
         .write          = cache_write_procfs,
         .poll           = cache_poll_procfs,
-        .ioctl          = cache_ioctl_procfs, /* for FIONREAD */
+        .unlocked_ioctl = cache_ioctl_procfs, /* for FIONREAD */
         .open           = cache_open_procfs,
         .release        = cache_release_procfs,
 };