[XFS] stop using uio in the readlink code

[deliverable/linux.git] / fs / xfs / linux-2.6 / xfs_ioctl.c

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index 5917808abbd6b0f9b1e98f3db6cc1c71c8ed0f67..47cfde6cfae2fc41adc3415143bcd6643a7b23a6 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -349,19 +349,44 @@ xfs_open_by_handle(
        return new_fd;
 }
 
+/*
+ * This is a copy from fs/namei.c:vfs_readlink(), except for removing it's
+ * unused first argument.
+ */
+STATIC int
+do_readlink(
+       char __user             *buffer,
+       int                     buflen,
+       const char              *link)
+{
+        int len;
+
+       len = PTR_ERR(link);
+       if (IS_ERR(link))
+               goto out;
+
+       len = strlen(link);
+       if (len > (unsigned) buflen)
+               len = buflen;
+       if (copy_to_user(buffer, link, len))
+               len = -EFAULT;
+ out:
+       return len;
+}
+
+
 STATIC int
 xfs_readlink_by_handle(
        xfs_mount_t             *mp,
        void                    __user *arg,
        struct inode            *parinode)
 {
-       int                     error;
-       struct iovec            aiov;
-       struct uio              auio;
        struct inode            *inode;
        xfs_fsop_handlereq_t    hreq;
        bhv_vnode_t             *vp;
        __u32                   olen;
+       void                    *link;
+       int                     error;
 
        if (!capable(CAP_SYS_ADMIN))
                return -XFS_ERROR(EPERM);
@@ -374,29 +399,31 @@ xfs_readlink_by_handle(
 
        /* Restrict this handle operation to symlinks only. */
        if (!S_ISLNK(inode->i_mode)) {
-               VN_RELE(vp);
-               return -XFS_ERROR(EINVAL);
+               error = -XFS_ERROR(EINVAL);
+               goto out_iput;
        }
 
        if (copy_from_user(&olen, hreq.ohandlen, sizeof(__u32))) {
-               VN_RELE(vp);
-               return -XFS_ERROR(EFAULT);
+               error = -XFS_ERROR(EFAULT);
+               goto out_iput;
        }
-       aiov.iov_len    = olen;
-       aiov.iov_base   = hreq.ohandle;
 
-       auio.uio_iov    = (struct kvec *)&aiov;
-       auio.uio_iovcnt = 1;
-       auio.uio_offset = 0;
-       auio.uio_segflg = UIO_USERSPACE;
-       auio.uio_resid  = olen;
+       link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
+       if (!link)
+               goto out_iput;
 
-       error = bhv_vop_readlink(vp, &auio, IO_INVIS, NULL);
-       VN_RELE(vp);
+       error = -bhv_vop_readlink(vp, link);
        if (error)
-               return -error;
+               goto out_kfree;
+       error = do_readlink(hreq.ohandle, olen, link);
+       if (error)
+               goto out_kfree;
 
-       return (olen - auio.uio_resid);
+ out_kfree:
+       kfree(link);
+ out_iput:
+       iput(inode);
+       return error;
 }
 
 STATIC int