From patchwork Fri Jan 17 10:07:07 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Shilovsky X-Patchwork-Id: 3503281 Return-Path: X-Original-To: patchwork-cifs-client@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BA394C02DD for ; Fri, 17 Jan 2014 10:07:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D02CA20165 for ; Fri, 17 Jan 2014 10:07:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E13C120131 for ; Fri, 17 Jan 2014 10:07:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752331AbaAQKHf (ORCPT ); Fri, 17 Jan 2014 05:07:35 -0500 Received: from mail-la0-f42.google.com ([209.85.215.42]:52941 "EHLO mail-la0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752298AbaAQKHc (ORCPT ); Fri, 17 Jan 2014 05:07:32 -0500 Received: by mail-la0-f42.google.com with SMTP id hr13so1406476lab.29 for ; Fri, 17 Jan 2014 02:07:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=fuIpvHQpf5KWqzjyyO3JAAh+8/pDAv1oGvNVMgbRykk=; b=HXFY/R+VZGVb600kUFAxOt5v5sALXrzE/tMjXCFUEufwMVOzb0AZHVfS8nhe4GflH3 jTL/cOK623H5qR4Oly/lBN8lwo7KMAfGcdxG2qeabVJUDBa2NvID4epYaJim2EZLGSr5 mooKYfGNk4psYSEqS+wvvGlL4PMbBqrcZcGen1ox6uTTLx5Cl/IQFGOX98ucK3mMx6kP aG/fKoLloh7IbX5e4d0X2ub+IMOTU8IC9trZKzgf3s/3KdD8w1dpGfLU/T3zLA/arcfd ABEG07ujNYKG4hOavXMZF2Zvk/ZY4bZnH3ky7asy+JGWErmHQhAJLce1iNsXpkuEeXax Ovzg== X-Received: by 10.152.4.134 with SMTP id k6mr258665lak.68.1389953250649; Fri, 17 Jan 2014 02:07:30 -0800 (PST) Received: from localhost.localdomain ([92.43.3.2]) by mx.google.com with ESMTPSA id e6sm6430005lbs.3.2014.01.17.02.07.27 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 17 Jan 2014 02:07:29 -0800 (PST) From: Pavel Shilovsky To: linux-kernel@vger.kernel.org Cc: linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, wine-devel@winehq.org Subject: [PATCH v7 2/7] VFS: Add O_DENYDELETE support for VFS Date: Fri, 17 Jan 2014 14:07:07 +0400 Message-Id: <1389953232-9428-3-git-send-email-piastry@etersoft.ru> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1389953232-9428-1-git-send-email-piastry@etersoft.ru> References: <1389953232-9428-1-git-send-email-piastry@etersoft.ru> Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce new LOCK_DELETE flock flag that is suggested to be used internally only to map O_DENYDELETE open flag: !O_DENYDELETE -> LOCK_DELETE | LOCK_MAND. Signed-off-by: Pavel Shilovsky --- fs/locks.c | 56 ++++++++++++++++++++++++++++++++------ fs/namei.c | 3 ++ include/linux/fs.h | 6 ++++ include/uapi/asm-generic/fcntl.h | 1 + 4 files changed, 57 insertions(+), 9 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index ffde4d4..7ecc511 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -295,7 +295,7 @@ EXPORT_SYMBOL(locks_copy_lock); static inline int flock_translate_cmd(int cmd) { if (cmd & LOCK_MAND) - return cmd & (LOCK_MAND | LOCK_RW); + return cmd & (LOCK_MAND | LOCK_RW | LOCK_DELETE); switch (cmd) { case LOCK_SH: return F_RDLCK; @@ -717,6 +717,8 @@ deny_flags_to_cmd(unsigned int flags) cmd |= LOCK_READ; if (!(flags & O_DENYWRITE)) cmd |= LOCK_WRITE; + if (!(flags & O_DENYDELETE)) + cmd |= LOCK_DELETE; return cmd; } @@ -941,6 +943,34 @@ out: return error; } +int +sharelock_may_delete(struct dentry *dentry) +{ + struct file_lock **before; + struct inode *inode = dentry->d_inode; + int rc = 0; + + if (!IS_SHARELOCK(inode)) + return rc; + + spin_lock(&inode->i_lock); + for_each_lock(inode, before) { + struct file_lock *fl = *before; + if (IS_POSIX(fl)) + break; + if (IS_LEASE(fl)) + continue; + if (!(fl->fl_type & LOCK_MAND)) + continue; + if (fl->fl_type & LOCK_DELETE) + continue; + rc = 1; + break; + } + spin_unlock(&inode->i_lock); + return rc; +} + /* * Determine if a file is allowed to be opened with specified access and share * modes. Lock the file and return 0 if checks passed, otherwise return @@ -955,10 +985,6 @@ sharelock_lock_file(struct file *filp) if (!IS_SHARELOCK(filp->f_path.dentry->d_inode)) return error; - /* Disable O_DENYDELETE support for now */ - if (filp->f_flags & O_DENYDELETE) - return -EINVAL; - error = flock_make_lock(filp, &lock, deny_flags_to_cmd(filp->f_flags)); if (error) return error; @@ -1872,6 +1898,12 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd) if (!f.file) goto out; + /* LOCK_DELETE is defined to be translated from O_DENYDELETE only */ + if (cmd & LOCK_DELETE) { + error = -EINVAL; + goto out; + } + can_sleep = !(cmd & LOCK_NB); cmd &= ~LOCK_NB; unlock = (cmd == LOCK_UN); @@ -2419,10 +2451,16 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, seq_printf(f, "UNKNOWN UNKNOWN "); } if (fl->fl_type & LOCK_MAND) { - seq_printf(f, "%s ", - (fl->fl_type & LOCK_READ) - ? (fl->fl_type & LOCK_WRITE) ? "RW " : "READ " - : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE "); + if (fl->fl_type & LOCK_DELETE) + seq_printf(f, "%s ", + (fl->fl_type & LOCK_READ) ? + (fl->fl_type & LOCK_WRITE) ? "RWDEL" : "RDDEL" : + (fl->fl_type & LOCK_WRITE) ? "WRDEL" : "DEL "); + else + seq_printf(f, "%s ", + (fl->fl_type & LOCK_READ) ? + (fl->fl_type & LOCK_WRITE) ? "RW " : "READ " : + (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE "); } else { seq_printf(f, "%s ", (lease_breaking(fl)) diff --git a/fs/namei.c b/fs/namei.c index 2b741a1..1643ab8 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2383,6 +2383,7 @@ static inline int check_sticky(struct inode *dir, struct inode *inode) * 9. We can't remove a root or mountpoint. * 10. We don't allow removal of NFS sillyrenamed files; it's handled by * nfs_async_unlink(). + * 11. We can't do it if victim is locked by O_DENYDELETE sharelock. */ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) { @@ -2416,6 +2417,8 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) return -ENOENT; if (victim->d_flags & DCACHE_NFSFS_RENAMED) return -EBUSY; + if (sharelock_may_delete(victim)) + return -ESHAREDENIED; return 0; } diff --git a/include/linux/fs.h b/include/linux/fs.h index aa061ca..6dc9275 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1030,6 +1030,7 @@ extern int lease_modify(struct file_lock **, int); extern int lock_may_read(struct inode *, loff_t start, unsigned long count); extern int lock_may_write(struct inode *, loff_t start, unsigned long count); extern int sharelock_lock_file(struct file *); +extern int sharelock_may_delete(struct dentry *); #else /* !CONFIG_FILE_LOCKING */ static inline int fcntl_getlk(struct file *file, struct flock __user *user) { @@ -1176,6 +1177,11 @@ static inline int sharelock_lock_file(struct file *filp) return 0; } +static inline int sharelock_may_delete(struct dentry *dentry) +{ + return 0; +} + #endif /* !CONFIG_FILE_LOCKING */ diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h index 9881cfe..41ba131 100644 --- a/include/uapi/asm-generic/fcntl.h +++ b/include/uapi/asm-generic/fcntl.h @@ -175,6 +175,7 @@ struct f_owner_ex { blocking */ #define LOCK_UN 8 /* remove lock */ +#define LOCK_DELETE 16 /* which allows to delete a file */ #define LOCK_MAND 32 /* This is a mandatory flock ... */ #define LOCK_READ 64 /* which allows concurrent read operations */ #define LOCK_WRITE 128 /* which allows concurrent write operations */