From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: [PATCH v5 11/19] vfs: fix linkat to retry on ESTALE errors Date: Wed, 8 Aug 2012 09:21:34 -0400 Message-ID: <1344432102-22312-12-git-send-email-jlayton@redhat.com> References: <1344432102-22312-1-git-send-email-jlayton@redhat.com> 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 To: viro@ZenIV.linux.org.uk Return-path: In-Reply-To: <1344432102-22312-1-git-send-email-jlayton@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Signed-off-by: Jeff Layton --- fs/namei.c | 60 ++++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 40 insertions(+), 20 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 9986117..d6e9754 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3565,6 +3565,8 @@ 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; @@ -3582,30 +3584,48 @@ 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 = may_linkat(&old_path); - if (unlikely(error)) - goto out_dput; - error = security_path_link(old_path.dentry, &new_path, new_dentry); - if (error) - goto out_dput; - 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 = may_linkat(&old_path); + if (unlikely(error)) + goto out_dput; + error = security_path_link(old_path.dentry, &new_path, + new_dentry); + if (error) + goto out_dput; + error = vfs_link(old_path.dentry, new_path.dentry->d_inode, + new_dentry); out_dput: - done_path_create(&new_path, new_dentry); + done_path_create(&new_path, new_dentry); out: - path_put(&old_path); - + path_put(&old_path); + how |= LOOKUP_REVAL; + } while (retry_estale(error, try++)); + putname(new); + putname(old); return error; } -- 1.7.11.2