Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751600AbdFFUp2 (ORCPT ); Tue, 6 Jun 2017 16:45:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42608 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751474AbdFFUpZ (ORCPT ); Tue, 6 Jun 2017 16:45:25 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 6F6D16522 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=bcodding@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 6F6D16522 From: Benjamin Coddington To: Jeff Layton , bfields@fieldses.org, Alexander Viro Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] fs/locks: Remove fl_nspid Date: Tue, 6 Jun 2017 16:45:22 -0400 Message-Id: In-Reply-To: References: In-Reply-To: References: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 06 Jun 2017 20:45:24 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4304 Lines: 131 Since commit c69899a17ca4 "NFSv4: Update of VFS byte range lock must be atomic with the stateid update", NFSv4 has been inserting locks in rpciod worker context. The result is that the file_lock's fl_nspid is the kworker's pid instead of the original userspace pid. The fl_nspid is only used to represent the namespaced virtual pid number when displaying locks or returning from F_GETLK. There's no reason to set it for every inserted lock, since we can usually just look it up from fl_pid. So, instead of looking up and holding struct pid for every lock, let's just look up the virtual pid number from fl_pid when it is needed. That means we can remove fl_nspid entirely. Signed-off-by: Benjamin Coddington --- fs/locks.c | 52 +++++++++++++++++++++++++++++----------------------- include/linux/fs.h | 1 - 2 files changed, 29 insertions(+), 24 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index d7daa6c8932f..8d48e4c42ed3 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -733,7 +733,6 @@ static void locks_wake_up_blocks(struct file_lock *blocker) static void locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before) { - fl->fl_nspid = get_pid(task_tgid(current)); list_add_tail(&fl->fl_list, before); locks_insert_global_locks(fl); } @@ -743,10 +742,6 @@ locks_unlink_lock_ctx(struct file_lock *fl) { locks_delete_global_locks(fl); list_del_init(&fl->fl_list); - if (fl->fl_nspid) { - put_pid(fl->fl_nspid); - fl->fl_nspid = NULL; - } locks_wake_up_blocks(fl); } @@ -823,8 +818,6 @@ posix_test_lock(struct file *filp, struct file_lock *fl) list_for_each_entry(cfl, &ctx->flc_posix, fl_list) { if (posix_locks_conflict(fl, cfl)) { locks_copy_conflock(fl, cfl); - if (cfl->fl_nspid) - fl->fl_pid = pid_vnr(cfl->fl_nspid); goto out; } } @@ -2048,6 +2041,25 @@ int vfs_test_lock(struct file *filp, struct file_lock *fl) } EXPORT_SYMBOL_GPL(vfs_test_lock); +/** + * locks_translate_pid - translate a pid number into a namespace + * @nr: The pid number in the init_pid_ns + * @ns: The namespace into which the pid should be translated + * + * Used to tranlate a fl_pid into a namespace virtual pid number + */ +static pid_t locks_translate_pid(int init_nr, struct pid_namespace *ns) +{ + pid_t vnr; + struct pid *pid; + + rcu_read_lock(); + pid = find_pid_ns(init_nr, &init_pid_ns); + vnr = pid_nr_ns(pid, ns); + rcu_read_unlock(); + return vnr; +} + static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl) { flock->l_pid = IS_OFDLCK(fl) ? -1 : fl->fl_pid; @@ -2584,22 +2596,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, { struct inode *inode = NULL; unsigned int fl_pid; + struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; - if (fl->fl_nspid) { - struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; - - /* Don't let fl_pid change based on who is reading the file */ - fl_pid = pid_nr_ns(fl->fl_nspid, proc_pidns); - - /* - * If there isn't a fl_pid don't display who is waiting on - * the lock if we are called from locks_show, or if we are - * called from __show_fd_info - skip lock entirely - */ - if (fl_pid == 0) - return; - } else - fl_pid = fl->fl_pid; + fl_pid = locks_translate_pid(fl->fl_pid, proc_pidns); + /* + * If there isn't a fl_pid don't display who is waiting on + * the lock if we are called from locks_show, or if we are + * called from __show_fd_info - skip lock entirely + */ + if (fl_pid == 0) + return; if (fl->fl_file != NULL) inode = locks_inode(fl->fl_file); @@ -2674,7 +2680,7 @@ static int locks_show(struct seq_file *f, void *v) fl = hlist_entry(v, struct file_lock, fl_link); - if (fl->fl_nspid && !pid_nr_ns(fl->fl_nspid, proc_pidns)) + if (locks_translate_pid(fl->fl_pid, proc_pidns) == 0) return 0; lock_get_status(f, fl, iter->li_pos, ""); diff --git a/include/linux/fs.h b/include/linux/fs.h index aa4affb38c39..b013fac515f7 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -984,7 +984,6 @@ struct file_lock { unsigned char fl_type; unsigned int fl_pid; int fl_link_cpu; /* what cpu's list is this on? */ - struct pid *fl_nspid; wait_queue_head_t fl_wait; struct file *fl_file; loff_t fl_start; -- 2.9.3