Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753864AbZIGPWR (ORCPT ); Mon, 7 Sep 2009 11:22:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753720AbZIGPWQ (ORCPT ); Mon, 7 Sep 2009 11:22:16 -0400 Received: from fxip-0047f.externet.hu ([88.209.222.127]:56461 "EHLO pomaz-ex.szeredi.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753527AbZIGPWQ (ORCPT ); Mon, 7 Sep 2009 11:22:16 -0400 To: akpm@linux-foundation.org CC: Valdis.Kletnieks@vt.edu, hugh.dickins@tiscali.co.uk, matthew@wil.cx, agruen@suse.de, viro@zeniv.linux.org.uk, hch@lst.de, linux-kernel@vger.kernel.org Subject: [patch] vfs: no "(unreachable)" prefix for SYSVIPC maps in /proc/PID/maps Message-Id: From: Miklos Szeredi Date: Mon, 07 Sep 2009 17:21:49 +0200 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3307 Lines: 100 Another fix for vfs-fix-d_path-for-unreachable-paths.patch in -mm. ---- From: Miklos Szeredi The patch "vfs: fix d_path() for unreachable paths" generally changed d_path() to report unreachable paths with a special prefix. This has an effect on /proc/${PID}/maps as well for memory maps set up with shmem_file_setup() or hugetlb_file_setup(). These functions set up unlinked files under a kernel-private vfsmount. Since this vfsmount is unreachable from userspace, these maps will be reported with the "(unreachable)" prefix. This is undesirable, because it changes the kernel ABI and might break applications for no good reason. Signed-off-by: Miklos Szeredi --- fs/hugetlbfs/inode.c | 17 +++++++++++++++++ mm/shmem.c | 17 +++++++++++++++++ 2 files changed, 34 insertions(+) Index: linux-2.6/mm/shmem.c =================================================================== --- linux-2.6.orig/mm/shmem.c 2009-09-07 16:27:57.000000000 +0200 +++ linux-2.6/mm/shmem.c 2009-09-07 16:46:41.000000000 +0200 @@ -2602,6 +2602,21 @@ int shmem_unuse(swp_entry_t entry, struc /* common code */ +/* + * Do a special d_dname function so that these are not prefixed by + * "(unreachable)". + */ +static char *shmem_unlinked_d_dname(struct dentry *dentry, char *buf, + int buflen) +{ + return dynamic_dname(dentry, buf, buflen, "/%s (deleted)", + dentry->d_name.name); +} + +static struct dentry_operations shmem_unlinked_dentry_operations = { + .d_dname = shmem_unlinked_d_dname, +}; + /** * shmem_file_setup - get an unlinked file living in tmpfs * @name: name for dentry (to be seen in /proc//maps @@ -2634,6 +2649,8 @@ struct file *shmem_file_setup(const char if (!dentry) goto put_memory; + dentry->d_op = &shmem_unlinked_dentry_operations; + error = -ENFILE; file = get_empty_filp(); if (!file) Index: linux-2.6/fs/hugetlbfs/inode.c =================================================================== --- linux-2.6.orig/fs/hugetlbfs/inode.c 2009-09-07 16:27:57.000000000 +0200 +++ linux-2.6/fs/hugetlbfs/inode.c 2009-09-07 16:46:51.000000000 +0200 @@ -930,6 +930,21 @@ static struct file_system_type hugetlbfs static struct vfsmount *hugetlbfs_vfsmount; +/* + * Do a special d_dname function so that these are not prefixed by + * "(unreachable)". + */ +static char *hugetlb_unlinked_d_dname(struct dentry *dentry, char *buf, + int buflen) +{ + return dynamic_dname(dentry, buf, buflen, "/%s (deleted)", + dentry->d_name.name); +} + +static struct dentry_operations hugetlb_unlinked_dentry_operations = { + .d_dname = hugetlb_unlinked_d_dname, +}; + static int can_do_hugetlb_shm(void) { return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); @@ -967,6 +982,8 @@ struct file *hugetlb_file_setup(const ch if (!dentry) goto out_shm_unlock; + dentry->d_op = &hugetlb_unlinked_dentry_operations; + error = -ENOSPC; inode = hugetlbfs_get_inode(root->d_sb, current_fsuid(), current_fsgid(), S_IFREG | S_IRWXUGO, 0); -- 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/