Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932543AbaAHWNm (ORCPT ); Wed, 8 Jan 2014 17:13:42 -0500 Received: from mail-ea0-f176.google.com ([209.85.215.176]:59254 "EHLO mail-ea0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932181AbaAHWJs (ORCPT ); Wed, 8 Jan 2014 17:09:48 -0500 From: Miklos Szeredi To: viro@ZenIV.linux.org.uk Cc: 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: [PATCH 03/11] vfs: rename: use common code for dir and non-dir Date: Wed, 8 Jan 2014 23:10:07 +0100 Message-Id: <1389219015-10980-4-git-send-email-miklos@szeredi.hu> X-Mailer: git-send-email 1.8.1.4 In-Reply-To: <1389219015-10980-1-git-send-email-miklos@szeredi.hu> References: <1389219015-10980-1-git-send-email-miklos@szeredi.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Miklos Szeredi There's actually very little difference between vfs_rename_dir() and vfs_rename_other() so move both inline into vfs_rename() which still stays reasonably readable. Signed-off-by: Miklos Szeredi --- fs/namei.c | 187 +++++++++++++++++++++++++------------------------------------ 1 file changed, 75 insertions(+), 112 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index d848b31a646e..f32a899fc039 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3962,7 +3962,27 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -/* +/** + * vfs_rename - rename a filesystem object + * @old_dir: parent of source + * @old_dentry: source + * @new_dir: parent of destination + * @new_dentry: destination + * @delegated_inode: returns an inode needing a delegation break + * + * The caller must hold multiple mutexes--see lock_rename()). + * + * If vfs_rename discovers a delegation in need of breaking at either + * the source or destination, it will return -EWOULDBLOCK and return a + * reference to the inode in delegated_inode. The caller should then + * break the delegation and retry. Because breaking a delegation may + * take a long time, the caller should drop all locks before doing + * so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + * * The worst of all namespace operations - renaming directory. "Perverted" * doesn't even start to describe it. Somebody in UCB had a heck of a trip... * Problems: @@ -3990,19 +4010,39 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ -static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode) { - int error = 0; + int error; + bool is_dir = d_is_dir(old_dentry); + const unsigned char *old_name; + struct inode *source = old_dentry->d_inode; struct inode *target = new_dentry->d_inode; - unsigned max_links = new_dir->i_sb->s_max_links; + + if (source == target) + return 0; + + error = may_delete(old_dir, old_dentry, is_dir); + if (error) + return error; + + if (!target) + error = may_create(new_dir, new_dentry); + else + error = may_delete(new_dir, new_dentry, is_dir); + if (error) + return error; + + if (!old_dir->i_op->rename) + return -EPERM; /* * If we are going to change the parent - check write permissions, * we'll need to flip '..'. */ - if (new_dir != old_dir) { - error = inode_permission(old_dentry->d_inode, MAY_WRITE); + if (is_dir && new_dir != old_dir) { + error = inode_permission(source, MAY_WRITE); if (error) return error; } @@ -4011,134 +4051,57 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, if (error) return error; + old_name = fsnotify_oldname_init(old_dentry->d_name.name); dget(new_dentry); - if (target) + 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; - error = -EMLINK; - if (max_links && !target && new_dir != old_dir && - new_dir->i_nlink >= max_links) - goto out; - - if (target) - shrink_dcache_parent(new_dentry); - error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - goto out; - - if (target) { - 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); -out: - if (target) - mutex_unlock(&target->i_mutex); - dput(new_dentry); - return error; -} - -static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - struct inode *target = new_dentry->d_inode; - struct inode *source = old_dentry->d_inode; - int error; - - error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - return error; - - dget(new_dentry); - lock_two_nondirectories(source, target); + if (is_dir) { + unsigned max_links = new_dir->i_sb->s_max_links; - error = -EBUSY; - if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) - goto out; + error = -EMLINK; + if (max_links && !target && new_dir != old_dir && + new_dir->i_nlink >= max_links) + goto out; - error = try_break_deleg(source, delegated_inode); - if (error) - goto out; - if (target) { - error = try_break_deleg(target, delegated_inode); + if (target) + shrink_dcache_parent(new_dentry); + } else { + error = try_break_deleg(source, delegated_inode); if (error) goto out; + if (target) { + error = try_break_deleg(target, delegated_inode); + if (error) + goto out; + } } error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); if (error) goto out; - if (target) + if (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); out: - unlock_two_nondirectories(source, target); + if (!is_dir) + unlock_two_nondirectories(source, target); + else if (target) + mutex_unlock(&target->i_mutex); dput(new_dentry); - return error; -} - -/** - * vfs_rename - rename a filesystem object - * @old_dir: parent of source - * @old_dentry: source - * @new_dir: parent of destination - * @new_dentry: destination - * @delegated_inode: returns an inode needing a delegation break - * - * The caller must hold multiple mutexes--see lock_rename()). - * - * If vfs_rename discovers a delegation in need of breaking at either - * the source or destination, it will return -EWOULDBLOCK and return a - * reference to the inode in delegated_inode. The caller should then - * break the delegation and retry. Because breaking a delegation may - * take a long time, the caller should drop all locks before doing - * so. - * - * Alternatively, a caller may pass NULL for delegated_inode. This may - * be appropriate for callers that expect the underlying filesystem not - * to be NFS exported. - */ -int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - int error; - int is_dir = d_is_dir(old_dentry); - const unsigned char *old_name; - - if (old_dentry->d_inode == new_dentry->d_inode) - return 0; - - error = may_delete(old_dir, old_dentry, is_dir); - if (error) - return error; - - if (!new_dentry->d_inode) - error = may_create(new_dir, new_dentry); - else - error = may_delete(new_dir, new_dentry, is_dir); - if (error) - return error; - - if (!old_dir->i_op->rename) - return -EPERM; - - old_name = fsnotify_oldname_init(old_dentry->d_name.name); - - if (is_dir) - error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); - else - error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode); if (!error) fsnotify_move(old_dir, new_dir, old_name, is_dir, - new_dentry->d_inode, old_dentry); + target, old_dentry); fsnotify_oldname_free(old_name); return error; -- 1.8.1.4 -- 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/