Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751368AbaAMHwd (ORCPT ); Mon, 13 Jan 2014 02:52:33 -0500 Received: from cantor2.suse.de ([195.135.220.15]:53785 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751246AbaAMHwa (ORCPT ); Mon, 13 Jan 2014 02:52:30 -0500 Date: Mon, 13 Jan 2014 08:52:27 +0100 From: Jan Kara To: Miklos Szeredi Cc: viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, dhowells@redhat.com, zab@redhat.com, jack@suse.cz, luto@amacapital.net, mszeredi@suse.cz Subject: Re: [PATCH 07/11] vfs: add cross-rename Message-ID: <20140113075227.GG3837@quack.suse.cz> References: <1389219015-10980-1-git-send-email-miklos@szeredi.hu> <1389219015-10980-8-git-send-email-miklos@szeredi.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1389219015-10980-8-git-send-email-miklos@szeredi.hu> 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 On Wed 08-01-14 23:10:11, Miklos Szeredi wrote: > From: Miklos Szeredi > > If flags contain RENAME_EXCHANGE then exchange source and destination files. > There's no restriction on the type of the files; e.g. a directory can be > exchanged with a symlink. > > Signed-off-by: Miklos Szeredi > --- > fs/dcache.c | 46 +++++++++++++++++---- > fs/namei.c | 107 +++++++++++++++++++++++++++++++++--------------- > include/linux/dcache.h | 1 + > include/uapi/linux/fs.h | 1 + > security/security.c | 16 ++++++++ > 5 files changed, 131 insertions(+), 40 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 3fbc95c72e31..97c6dbb47eca 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -4020,6 +4020,8 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, > const unsigned char *old_name; > struct inode *source = old_dentry->d_inode; > struct inode *target = new_dentry->d_inode; > + bool new_is_dir = false; > + unsigned max_links = new_dir->i_sb->s_max_links; > > if (source == target) > return 0; > @@ -4028,10 +4030,16 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, > if (error) > return error; > > - if (!target) > + if (!target) { > error = may_create(new_dir, new_dentry); > - else > - error = may_delete(new_dir, new_dentry, is_dir); > + } else { > + new_is_dir = d_is_dir(new_dentry); > + > + if (!(flags & RENAME_EXCHANGE)) > + error = may_delete(new_dir, new_dentry, is_dir); > + else > + error = may_delete(new_dir, new_dentry, new_is_dir); > + } > if (error) > return error; > > @@ -4042,10 +4050,17 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, > * If we are going to change the parent - check write permissions, > * we'll need to flip '..'. > */ > - if (is_dir && new_dir != old_dir) { > - error = inode_permission(source, MAY_WRITE); > - if (error) > - return error; > + if (new_dir != old_dir) { > + if (is_dir) { > + error = inode_permission(source, MAY_WRITE); > + if (error) > + return error; > + } > + if ((flags & RENAME_EXCHANGE) && new_is_dir) { > + error = inode_permission(target, MAY_WRITE); > + if (error) > + return error; > + } > } > > error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry, > @@ -4055,25 +4070,24 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, > > old_name = fsnotify_oldname_init(old_dentry->d_name.name); > dget(new_dentry); > - if (!is_dir) > - lock_two_nondirectories(source, target); > - else if (target) > - mutex_lock(&target->i_mutex); > + if (!(flags & RENAME_EXCHANGE)) { > + if (!is_dir) > + lock_two_nondirectories(source, target); > + else if (target) > + mutex_lock(&target->i_mutex); > + } > > error = -EBUSY; > if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry)) > goto out; > > - if (is_dir) { > - unsigned max_links = new_dir->i_sb->s_max_links; > - > + if (max_links && new_dir != old_dir) { > error = -EMLINK; > - if (max_links && !target && new_dir != old_dir && > - new_dir->i_nlink >= max_links) > + if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links) > + goto out; > + if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir && > + old_dir->i_nlink > max_links) This should be >=, shouldn't it? > goto out; > - > - if (target) > - shrink_dcache_parent(new_dentry); > } else { > error = try_break_deleg(source, delegated_inode); > if (error) > @@ -4084,27 +4098,40 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, > goto out; > } > } > + if (is_dir && !(flags & RENAME_EXCHANGE) && target) > + shrink_dcache_parent(new_dentry); > error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry, > flags); > if (error) > goto out; > > - if (target) { > + if (!(flags & RENAME_EXCHANGE) && target) { > if (is_dir) > target->i_flags |= S_DEAD; > dont_mount(new_dentry); > } > - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) > - d_move(old_dentry, new_dentry); > + if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) { > + if (!(flags & RENAME_EXCHANGE)) > + d_move(old_dentry, new_dentry); > + else > + d_exchange(old_dentry, new_dentry); > + } > out: > - if (!is_dir) > - unlock_two_nondirectories(source, target); > - else if (target) > - mutex_unlock(&target->i_mutex); > + if (!(flags & RENAME_EXCHANGE)) { > + if (!is_dir) > + unlock_two_nondirectories(source, target); > + else if (target) > + mutex_unlock(&target->i_mutex); > + } > dput(new_dentry); > - if (!error) > + if (!error) { > fsnotify_move(old_dir, new_dir, old_name, is_dir, > - target, old_dentry); > + !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry); > + if (flags & RENAME_EXCHANGE) { > + fsnotify_move(new_dir, old_dir, old_dentry->d_name.name, > + new_is_dir, NULL, new_dentry); > + } > + } > fsnotify_oldname_free(old_name); > > return error; > @@ -4124,9 +4151,12 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, > bool should_retry = false; > int error; > > - if (flags & ~RENAME_NOREPLACE) > + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) > return -EOPNOTSUPP; > > + if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE)) > + return -EINVAL; > + > retry: > from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags); > if (IS_ERR(from)) { > @@ -4161,7 +4191,8 @@ retry: > > oldnd.flags &= ~LOOKUP_PARENT; > newnd.flags &= ~LOOKUP_PARENT; > - newnd.flags |= LOOKUP_RENAME_TARGET; > + if (!(flags & RENAME_EXCHANGE)) > + newnd.flags |= LOOKUP_RENAME_TARGET; > > retry_deleg: > trap = lock_rename(new_dir, old_dir); > @@ -4181,12 +4212,23 @@ retry_deleg: > error = -EEXIST; > if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) > goto exit5; > + if (flags & RENAME_EXCHANGE) { > + error = -ENOENT; > + if (!new_dentry->d_inode) > + goto exit5; Should this be d_is_positive()? Honza -- Jan Kara SUSE Labs, CR -- 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/