OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_CREATE

Add the VirtioFsFuseOpenOrCreate() function, for sending the FUSE_CREATE
command to the Virtio Filesystem device.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-21-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

3 files changed, 165 insertions, 0 deletions

diff --git a/OvmfPkg/VirtioFsDxe/FuseOpenOrCreate.c b/OvmfPkg/VirtioFsDxe/FuseOpenOrCreate.c
new file mode 100644
index 0000000..60ab002
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/FuseOpenOrCreate.c
@@ -0,0 +1,155 @@
+/** @file

+  FUSE_CREATE wrapper for the Virtio Filesystem device.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include <Library/BaseLib.h> // AsciiStrSize()

+

+#include "VirtioFsDxe.h"

+

+/**

+  Send a FUSE_CREATE request to the Virtio Filesystem device, for opening a

+  regular file with (O_RDWR | O_CREAT) semantics.

+

+  The function may only be called after VirtioFsFuseInitSession() returns

+  successfully and before VirtioFsUninit() is called.

+

+  @param[in,out] VirtioFs  The Virtio Filesystem device to send the FUSE_CREATE

+                           request to. On output, the FUSE request counter

+                           "VirtioFs->RequestId" will have been incremented.

+

+  @param[in] ParentNodeId  The inode number of the direct parent directory of

+                           the regular file to open or create.

+

+  @param[in] Name          The single-component filename of the regular file to

+                           open or create, under the parent directory

+                           identified by ParentNodeId.

+

+  @param[out] NodeId       The inode number of the regular file, returned by

+                           the Virtio Filesystem device.

+

+  @param[out] FuseHandle   The open file handle returned by the Virtio

+                           Filesystem device.

+

+  @retval EFI_SUCCESS  The regular file has been opened, and (if necessary)

+                       created.

+

+  @return              The "errno" value mapped to an EFI_STATUS code, if the

+                       Virtio Filesystem device explicitly reported an error.

+

+  @return              Error codes propagated from VirtioFsSgListsValidate(),

+                       VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),

+                       VirtioFsFuseCheckResponse().

+**/

+EFI_STATUS

+VirtioFsFuseOpenOrCreate (

+  IN OUT VIRTIO_FS *VirtioFs,

+  IN     UINT64    ParentNodeId,

+  IN     CHAR8     *Name,

+     OUT UINT64    *NodeId,

+     OUT UINT64    *FuseHandle

+  )

+{

+  VIRTIO_FS_FUSE_REQUEST             CommonReq;

+  VIRTIO_FS_FUSE_CREATE_REQUEST      CreateReq;

+  VIRTIO_FS_IO_VECTOR                ReqIoVec[3];

+  VIRTIO_FS_SCATTER_GATHER_LIST      ReqSgList;

+  VIRTIO_FS_FUSE_RESPONSE            CommonResp;

+  VIRTIO_FS_FUSE_NODE_RESPONSE       NodeResp;

+  VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE AttrResp;

+  VIRTIO_FS_FUSE_OPEN_RESPONSE       OpenResp;

+  VIRTIO_FS_IO_VECTOR                RespIoVec[4];

+  VIRTIO_FS_SCATTER_GATHER_LIST      RespSgList;

+  EFI_STATUS                         Status;

+

+  //

+  // Set up the scatter-gather lists.

+  //

+  ReqIoVec[0].Buffer = &CommonReq;

+  ReqIoVec[0].Size   = sizeof CommonReq;

+  ReqIoVec[1].Buffer = &CreateReq;

+  ReqIoVec[1].Size   = sizeof CreateReq;

+  ReqIoVec[2].Buffer = Name;

+  ReqIoVec[2].Size   = AsciiStrSize (Name);

+  ReqSgList.IoVec    = ReqIoVec;

+  ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);

+

+  RespIoVec[0].Buffer = &CommonResp;

+  RespIoVec[0].Size   = sizeof CommonResp;

+  RespIoVec[1].Buffer = &NodeResp;

+  RespIoVec[1].Size   = sizeof NodeResp;

+  RespIoVec[2].Buffer = &AttrResp;

+  RespIoVec[2].Size   = sizeof AttrResp;

+  RespIoVec[3].Buffer = &OpenResp;

+  RespIoVec[3].Size   = sizeof OpenResp;

+  RespSgList.IoVec    = RespIoVec;

+  RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);

+

+  //

+  // Validate the scatter-gather lists; calculate the total transfer sizes.

+  //

+  Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Populate the common request header.

+  //

+  Status = VirtioFsFuseNewRequest (VirtioFs, &CommonReq, ReqSgList.TotalSize,

+             VirtioFsFuseOpCreate, ParentNodeId);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Populate the FUSE_CREATE-specific fields.

+  //

+  // VIRTIO_FS_FUSE_OPEN_REQ_F_RDWR is why this request can never open a

+  // directory (EISDIR). And VIRTIO_FS_FUSE_OPEN_REQ_F_RDWR is consistent with

+  // the only OpenMode of EFI_FILE_PROTOCOL.Open() that enables filesystem

+  // object creation -- that is, Create/Read/Write.

+  //

+  CreateReq.Flags   = VIRTIO_FS_FUSE_OPEN_REQ_F_RDWR;

+  CreateReq.Mode    = (VIRTIO_FS_FUSE_MODE_PERM_RUSR |

+                       VIRTIO_FS_FUSE_MODE_PERM_WUSR |

+                       VIRTIO_FS_FUSE_MODE_PERM_RGRP |

+                       VIRTIO_FS_FUSE_MODE_PERM_WGRP |

+                       VIRTIO_FS_FUSE_MODE_PERM_ROTH |

+                       VIRTIO_FS_FUSE_MODE_PERM_WOTH);

+  CreateReq.Umask   = 0;

+  CreateReq.Padding = 0;

+

+  //

+  // Submit the request.

+  //

+  Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Verify the response (all response buffers are fixed size).

+  //

+  Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);

+  if (EFI_ERROR (Status)) {

+    if (Status == EFI_DEVICE_ERROR) {

+      DEBUG ((DEBUG_ERROR, "%a: Label=\"%s\" ParentNodeId=%Lu Name=\"%a\" "

+        "Errno=%d\n", __FUNCTION__, VirtioFs->Label, ParentNodeId, Name,

+        CommonResp.Error));

+      Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);

+    }

+    return Status;

+  }

+

+  //

+  // Output the NodeId of the (possibly new) regular file. Also output the open

+  // file handle.

+  //

+  *NodeId     = NodeResp.NodeId;

+  *FuseHandle = OpenResp.FileHandle;

+  return EFI_SUCCESS;

+}

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index 8fd56bd..795cf4e 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -286,6 +286,15 @@ VirtioFsFuseOpenDir (
      OUT UINT64    *FuseHandle

   );

 

+EFI_STATUS

+VirtioFsFuseOpenOrCreate (

+  IN OUT VIRTIO_FS *VirtioFs,

+  IN     UINT64    ParentNodeId,

+  IN     CHAR8     *Name,

+     OUT UINT64    *NodeId,

+     OUT UINT64    *FuseHandle

+  );

+

 //

 // EFI_SIMPLE_FILE_SYSTEM_PROTOCOL member functions for the Virtio Filesystem

 // driver.

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
index eebb86f..b942baa 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
@@ -89,6 +89,7 @@
   FuseMkDir.c

   FuseOpen.c

   FuseOpenDir.c

+  FuseOpenOrCreate.c

   FuseRelease.c

   Helpers.c

   SimpleFsClose.c