From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90CE6C433E0 for ; Fri, 26 Feb 2021 06:51:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 314C664ECE for ; Fri, 26 Feb 2021 06:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229586AbhBZGvR (ORCPT ); Fri, 26 Feb 2021 01:51:17 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:12583 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbhBZGvR (ORCPT ); Fri, 26 Feb 2021 01:51:17 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Dn0by6MRJzMfMs; Fri, 26 Feb 2021 14:48:30 +0800 (CST) Received: from huawei.com (10.151.151.241) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.498.0; Fri, 26 Feb 2021 14:50:25 +0800 From: Luo Longjun To: , , CC: , , , , Subject: [PATCH v3] fs/locks: print full locks information Date: Thu, 25 Feb 2021 22:58:29 -0500 Message-ID: <685386c2840b76c49b060bf7dcea1fefacf18176.1614322182.git.luolongjun@huawei.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210221201024.GB15975@fieldses.org> References: <20210221201024.GB15975@fieldses.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.151.151.241] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Commit fd7732e033e3 ("fs/locks: create a tree of dependent requests.") has put blocked locks into a tree. So, with a for loop, we can't check all locks information. To solve this problem, we should traverse the tree. Signed-off-by: Luo Longjun --- fs/locks.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 56 insertions(+), 9 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index 99ca97e81b7a..ecaecd1f1b58 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2828,7 +2828,7 @@ struct locks_iterator { }; static void lock_get_status(struct seq_file *f, struct file_lock *fl, - loff_t id, char *pfx) + loff_t id, char *pfx, int repeat) { struct inode *inode = NULL; unsigned int fl_pid; @@ -2844,7 +2844,11 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, if (fl->fl_file != NULL) inode = locks_inode(fl->fl_file); - seq_printf(f, "%lld:%s ", id, pfx); + seq_printf(f, "%lld: ", id); + + if (repeat) + seq_printf(f, "%*s", repeat - 1 + (int)strlen(pfx), pfx); + if (IS_POSIX(fl)) { if (fl->fl_flags & FL_ACCESS) seq_puts(f, "ACCESS"); @@ -2906,21 +2910,64 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, } } +static struct file_lock *get_next_blocked_member(struct file_lock *node) +{ + struct file_lock *tmp; + + /* NULL node or root node */ + if (node == NULL || node->fl_blocker == NULL) + return NULL; + + /* Next member in the linked list could be itself */ + tmp = list_next_entry(node, fl_blocked_member); + if (list_entry_is_head(tmp, &node->fl_blocker->fl_blocked_requests, fl_blocked_member) + || tmp == node) { + return NULL; + } + + return tmp; +} + static int locks_show(struct seq_file *f, void *v) { struct locks_iterator *iter = f->private; - struct file_lock *fl, *bfl; + struct file_lock *cur, *tmp; struct pid_namespace *proc_pidns = proc_pid_ns(file_inode(f->file)->i_sb); + int level = 0; - fl = hlist_entry(v, struct file_lock, fl_link); + cur = hlist_entry(v, struct file_lock, fl_link); - if (locks_translate_pid(fl, proc_pidns) == 0) + if (locks_translate_pid(cur, proc_pidns) == 0) return 0; - lock_get_status(f, fl, iter->li_pos, ""); + /* View this crossed linked list as a binary tree, the first member of fl_blocked_requests + * is the left child of current node, the next silibing in fl_blocked_member is the + * right child, we can alse get the parent of current node from fl_blocker, so this + * question becomes traversal of a binary tree + */ + while (cur != NULL) { + if (level) + lock_get_status(f, cur, iter->li_pos, "-> ", level); + else + lock_get_status(f, cur, iter->li_pos, "", level); - list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member) - lock_get_status(f, bfl, iter->li_pos, " ->"); + if (!list_empty(&cur->fl_blocked_requests)) { + /* Turn left */ + cur = list_first_entry_or_null(&cur->fl_blocked_requests, + struct file_lock, fl_blocked_member); + level++; + } else { + /* Turn right */ + tmp = get_next_blocked_member(cur); + /* Fall back to parent node */ + while (tmp == NULL && cur->fl_blocker != NULL) { + cur = cur->fl_blocker; + level--; + tmp = get_next_blocked_member(cur); + } + cur = tmp; + } + } return 0; } @@ -2941,7 +2988,7 @@ static void __show_fd_locks(struct seq_file *f, (*id)++; seq_puts(f, "lock:\t"); - lock_get_status(f, fl, *id, ""); + lock_get_status(f, fl, *id, "", 0); } } -- 2.17.1