Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753553Ab3HaCmk (ORCPT ); Fri, 30 Aug 2013 22:42:40 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:35812 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752504Ab3HaCmj (ORCPT ); Fri, 30 Aug 2013 22:42:39 -0400 Date: Sat, 31 Aug 2013 03:42:33 +0100 From: Al Viro To: Waiman Long Cc: Linus Torvalds , Ingo Molnar , Benjamin Herrenschmidt , Jeff Layton , Miklos Szeredi , Ingo Molnar , Thomas Gleixner , linux-fsdevel , Linux Kernel Mailing List , Peter Zijlstra , Steven Rostedt , Andi Kleen , "Chandramouleeswaran, Aswin" , "Norton, Scott J" Subject: Re: [PATCH v7 1/4] spinlock: A new lockref structure for lockless update of refcount Message-ID: <20130831024233.GJ13318@ZenIV.linux.org.uk> References: <5220E56A.80603@hp.com> <5220F090.5050908@hp.com> <20130830194059.GC13318@ZenIV.linux.org.uk> <5220F811.9060902@hp.com> <20130830202608.GD13318@ZenIV.linux.org.uk> <52210225.60805@hp.com> <20130830204852.GE13318@ZenIV.linux.org.uk> <52214EBC.90100@hp.com> <20130831023516.GI13318@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130831023516.GI13318@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1866 Lines: 49 On Sat, Aug 31, 2013 at 03:35:16AM +0100, Al Viro wrote: > Aha... OK, I see what's going on. We end up with shm_mnt *not* marked > as long-living vfsmount, even though it lives forever. See if the > following helps; if it does (and I very much expect it to), we want to > put it in -stable. As it is, you get slow path in mntput() each time > a file created by shmem_file_setup() gets closed. For no reason whatsoever... We still want MS_NOUSER on shm_mnt, so we'd better make sure that shmem_fill_super() sets it on the internal instance... Fixed variant follows: Signed-off-by: Al Viro diff --git a/mm/shmem.c b/mm/shmem.c index e43dc55..5261498 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2615,13 +2615,15 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent) * tmpfs instance, limiting inodes to one per page of lowmem; * but the internal instance is left unlimited. */ - if (!(sb->s_flags & MS_NOUSER)) { + if (!(sb->s_flags & MS_KERNMOUNT)) { sbinfo->max_blocks = shmem_default_max_blocks(); sbinfo->max_inodes = shmem_default_max_inodes(); if (shmem_parse_options(data, sbinfo, false)) { err = -EINVAL; goto failed; } + } else { + sb->s_flags |= MS_NOUSER; } sb->s_export_op = &shmem_export_ops; sb->s_flags |= MS_NOSEC; @@ -2831,8 +2833,7 @@ int __init shmem_init(void) goto out2; } - shm_mnt = vfs_kern_mount(&shmem_fs_type, MS_NOUSER, - shmem_fs_type.name, NULL); + shm_mnt = kern_mount(&shmem_fs_type); if (IS_ERR(shm_mnt)) { error = PTR_ERR(shm_mnt); printk(KERN_ERR "Could not kern_mount tmpfs\n"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/