From b89f432133851a01c0d28822f11cbdcc15781a75 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sat, 18 Sep 2010 15:09:31 +0200 Subject: fs/locks.c: prepare for BKL removal This prepares the removal of the big kernel lock from the file locking code. We still use the BKL as long as fs/lockd uses it and ceph might sleep, but we can flip the definition to a private spinlock as soon as that's done. All users outside of fs/lockd get converted to use lock_flocks() instead of lock_kernel() where appropriate. Based on an earlier patch to use a spinlock from Matthew Wilcox, who has attempted this a few times before, the earliest patch from over 10 years ago turned it into a semaphore, which ended up being slower than the BKL and was subsequently reverted. Someone should do some serious performance testing when this becomes a spinlock, since this has caused problems before. Using a spinlock should be at least as good as the BKL in theory, but who knows... Signed-off-by: Arnd Bergmann Acked-by: Matthew Wilcox Cc: Christoph Hellwig Cc: Trond Myklebust Cc: "J. Bruce Fields" Cc: Andrew Morton Cc: Miklos Szeredi Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: John Kacur Cc: Sage Weil Cc: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org --- fs/cifs/cifsfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 4e273f7793f6..50208c15309a 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -562,8 +562,8 @@ static loff_t cifs_llseek(struct file *file, loff_t offset, int origin) static int cifs_setlease(struct file *file, long arg, struct file_lock **lease) { - /* note that this is called by vfs setlease with the BKL held - although I doubt that BKL is needed here in cifs */ + /* note that this is called by vfs setlease with lock_flocks held + to protect *lease from going away */ struct inode *inode = file->f_path.dentry->d_inode; if (!(S_ISREG(inode->i_mode))) -- cgit v1.2.3