fs/locks: Use percpu_down_read_preempt_disable()

Avoid spurious preemption.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: paulmck@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: tj@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/fs/locks.c b/fs/locks.c
index c33aa77..133fb25 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -930,7 +930,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request)
                        return -ENOMEM;
        }
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
        if (request->fl_flags & FL_ACCESS)
                goto find_conflict;
@@ -971,7 +971,7 @@ find_conflict:
 
 out:
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
        if (new_fl)
                locks_free_lock(new_fl);
        locks_dispose_list(&dispose);
@@ -1008,7 +1008,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
                new_fl2 = locks_alloc_lock();
        }
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
        /*
         * New lock request. Walk all POSIX locks and look for conflicts. If
@@ -1180,7 +1180,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request,
        }
  out:
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
        /*
         * Free any unused locks.
         */
@@ -1455,7 +1455,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
                return error;
        }
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
 
        time_out_leases(inode, &dispose);
@@ -1507,13 +1507,13 @@ restart:
        locks_insert_block(fl, new_fl);
        trace_break_lease_block(inode, new_fl);
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
 
        locks_dispose_list(&dispose);
        error = wait_event_interruptible_timeout(new_fl->fl_wait,
                                                !new_fl->fl_next, break_time);
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
        trace_break_lease_unblock(inode, new_fl);
        locks_delete_block(new_fl);
@@ -1530,7 +1530,7 @@ restart:
        }
 out:
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
        locks_dispose_list(&dispose);
        locks_free_lock(new_fl);
        return error;
@@ -1685,7 +1685,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr
                return -EINVAL;
        }
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
        time_out_leases(inode, &dispose);
        error = check_conflicting_open(dentry, arg, lease->fl_flags);
@@ -1756,7 +1756,7 @@ out_setup:
                lease->fl_lmops->lm_setup(lease, priv);
 out:
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
        locks_dispose_list(&dispose);
        if (is_deleg)
                inode_unlock(inode);
@@ -1779,7 +1779,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
                return error;
        }
 
-       percpu_down_read(&file_rwsem);
+       percpu_down_read_preempt_disable(&file_rwsem);
        spin_lock(&ctx->flc_lock);
        list_for_each_entry(fl, &ctx->flc_lease, fl_list) {
                if (fl->fl_file == filp &&
@@ -1792,7 +1792,7 @@ static int generic_delete_lease(struct file *filp, void *owner)
        if (victim)
                error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose);
        spin_unlock(&ctx->flc_lock);
-       percpu_up_read(&file_rwsem);
+       percpu_up_read_preempt_enable(&file_rwsem);
        locks_dispose_list(&dispose);
        return error;
 }