Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-yx0-f174.google.com ([209.85.213.174]:41418 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932727Ab2F2S6X (ORCPT ); Fri, 29 Jun 2012 14:58:23 -0400 Received: by mail-yx0-f174.google.com with SMTP id l2so3038059yen.19 for ; Fri, 29 Jun 2012 11:58:23 -0700 (PDT) From: Jeff Layton To: viro@ZenIV.linux.org.uk Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, michael.brantley@deshaw.com, hch@infradead.org, miklos@szeredi.hu, pstaubach@exagrid.com Subject: [PATCH v3 11/17] vfs: fix linkat to retry on ESTALE errors Date: Fri, 29 Jun 2012 14:57:54 -0400 Message-Id: <1340996280-27123-12-git-send-email-jlayton@redhat.com> In-Reply-To: <1340996280-27123-1-git-send-email-jlayton@redhat.com> References: <1340996280-27123-1-git-send-email-jlayton@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Signed-off-by: Jeff Layton --- fs/namei.c | 67 ++++++++++++++++++++++++++++++++++++++--------------------- 1 files changed, 43 insertions(+), 24 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index a2d691a..e902770 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3138,6 +3138,8 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, struct path old_path, new_path; int how = 0; int error; + char *old, *new; + unsigned int try = 0; if ((flags & ~(AT_SYMLINK_FOLLOW | AT_EMPTY_PATH)) != 0) return -EINVAL; @@ -3155,34 +3157,51 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, if (flags & AT_SYMLINK_FOLLOW) how |= LOOKUP_FOLLOW; - error = user_path_at(olddfd, oldname, how, &old_path); - if (error) - return error; + old = getname_flags(oldname, how, NULL); + if (IS_ERR(old)) + return PTR_ERR(old); - new_dentry = user_path_create(newdfd, newname, &new_path, 0); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) - goto out; + new = getname(newname); + if (IS_ERR(new)) { + putname(old); + return PTR_ERR(new); + } - error = -EXDEV; - if (old_path.mnt != new_path.mnt) - goto out_dput; - error = mnt_want_write(new_path.mnt); - if (error) - goto out_dput; - error = security_path_link(old_path.dentry, &new_path, new_dentry); - if (error) - goto out_drop_write; - error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry); + do { + error = kern_path_at(olddfd, old, how, &old_path); + if (error) + break; + + new_dentry = kern_path_create(newdfd, new, &new_path, 0, try); + error = PTR_ERR(new_dentry); + if (IS_ERR(new_dentry)) { + path_put(&old_path); + break; + } + + error = -EXDEV; + if (old_path.mnt != new_path.mnt) + goto out_dput; + error = mnt_want_write(new_path.mnt); + if (error) + goto out_dput; + error = security_path_link(old_path.dentry, &new_path, + new_dentry); + if (error) + goto out_drop_write; + error = vfs_link(old_path.dentry, new_path.dentry->d_inode, + new_dentry); out_drop_write: - mnt_drop_write(new_path.mnt); + mnt_drop_write(new_path.mnt); out_dput: - dput(new_dentry); - mutex_unlock(&new_path.dentry->d_inode->i_mutex); - path_put(&new_path); -out: - path_put(&old_path); - + dput(new_dentry); + mutex_unlock(&new_path.dentry->d_inode->i_mutex); + path_put(&new_path); + path_put(&old_path); + how |= LOOKUP_REVAL; + } while (retry_estale(error, try++)); + putname(new); + putname(old); return error; } -- 1.7.7.6