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Commit 87709e28 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

fs/locks: Use percpu_down_read_preempt_disable() 



Avoid spurious preemption.

Signed-off-by: default avatarPeter 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: default avatarIngo Molnar <mingo@kernel.org>
parent 259d69b7

fs/locks.c

+12 −12
Original line number Diff line number Diff line
@@ -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 @@ static int flock_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);

	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 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) 
	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 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) 
	}

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 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr 
		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;

}