Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html