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/nfs/nfs4state.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 3e2f19b..96524c5 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -40,7 +40,7 @@ #include #include -#include +#include #include #include #include @@ -970,13 +970,13 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_ /* Guard against delegation returns and new lock/unlock calls */ down_write(&nfsi->rwsem); /* Protect inode->i_flock using the BKL */ - lock_kernel(); + lock_flocks(); for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK))) continue; if (nfs_file_open_context(fl->fl_file)->state != state) continue; - unlock_kernel(); + unlock_flocks(); status = ops->recover_lock(state, fl); switch (status) { case 0: @@ -1003,9 +1003,9 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_ /* kill_proc(fl->fl_pid, SIGLOST, 1); */ status = 0; } - lock_kernel(); + lock_flocks(); } - unlock_kernel(); + unlock_flocks(); out: up_write(&nfsi->rwsem); return status; -- cgit v1.1