OvmfPkg/VirtioFsDxe: convert FUSE inode attributes to EFI_FILE_INFO

Introduce the VirtioFsFuseAttrToEfiFileInfo() function, for converting
FUSE inode attributes to EFI_FILE_INFO.

The EpochToEfiTime() function from EmbeddedPkg's TimeBaseLib proves
invaluable for converting the file access times.

This is the first time we consume TimeBaseLib in OvmfPkg, so add the
necessary lib class resolution. We need not modify any ArmVirtPkg DSC
files: see commit af5fed90bfbf ("ArmPlatformPkg,ArmVirtPkg: delete
redundant PL031 functions", 2017-05-10).

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: <20201216211125.19496-22-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

3 files changed, 128 insertions, 0 deletions

diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index 8ffdabfd40..e9582e46bd 100644
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -9,6 +9,7 @@
 #include <Library/BaseLib.h>             // StrLen()

 #include <Library/BaseMemoryLib.h>       // CopyMem()

 #include <Library/MemoryAllocationLib.h> // AllocatePool()

+#include <Library/TimeBaseLib.h>         // EpochToEfiTime()

 #include <Library/VirtioLib.h>           // Virtio10WriteFeatures()

 

 #include "VirtioFsDxe.h"

@@ -1589,3 +1590,121 @@ FreeRhsPath8:
   FreePool (RhsPath8);

   return Status;

 }

+

+/**

+  Convert select fields of a VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE object to

+  corresponding fields in EFI_FILE_INFO.

+

+  @param[in] FuseAttr   The VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE object to

+                        convert the relevant fields from.

+

+  @param[out] FileInfo  The EFI_FILE_INFO structure to modify. Importantly, the

+                        FileInfo->Size and FileInfo->FileName fields are not

+                        overwritten.

+

+  @retval EFI_SUCCESS      Conversion successful.

+

+  @retval EFI_UNSUPPORTED  The allocated size of the file is inexpressible in

+                           EFI_FILE_INFO.

+

+  @retval EFI_UNSUPPORTED  One of the file access times is inexpressible in

+                           EFI_FILE_INFO.

+

+  @retval EFI_UNSUPPORTED  The file type is inexpressible in EFI_FILE_INFO.

+

+  @retval EFI_UNSUPPORTED  The file is a regular file that has multiple names

+                           on the host side (i.e., its hard link count is

+                           greater than one).

+**/

+EFI_STATUS

+VirtioFsFuseAttrToEfiFileInfo (

+  IN     VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE *FuseAttr,

+     OUT EFI_FILE_INFO                      *FileInfo

+  )

+{

+  UINT64   EpochTime[3];

+  EFI_TIME *ConvertedTime[ARRAY_SIZE (EpochTime)];

+  UINTN    Idx;

+

+  FileInfo->FileSize = FuseAttr->Size;

+

+  //

+  // The unit for FuseAttr->Blocks is 512B.

+  //

+  if (FuseAttr->Blocks >= BIT55) {

+    return EFI_UNSUPPORTED;

+  }

+  FileInfo->PhysicalSize = LShiftU64 (FuseAttr->Blocks, 9);

+

+  //

+  // Convert the timestamps. File creation time is not tracked by the Virtio

+  // Filesystem device, so set FileInfo->CreateTime from FuseAttr->Mtime as

+  // well.

+  //

+  EpochTime[0]     = FuseAttr->Mtime;

+  EpochTime[1]     = FuseAttr->Atime;

+  EpochTime[2]     = FuseAttr->Mtime;

+  ConvertedTime[0] = &FileInfo->CreateTime;

+  ConvertedTime[1] = &FileInfo->LastAccessTime;

+  ConvertedTime[2] = &FileInfo->ModificationTime;

+

+  for (Idx = 0; Idx < ARRAY_SIZE (EpochTime); Idx++) {

+    //

+    // EpochToEfiTime() takes a UINTN for seconds.

+    //

+    if (EpochTime[Idx] > MAX_UINTN) {

+      return EFI_UNSUPPORTED;

+    }

+    //

+    // Set the following fields in the converted time: Year, Month, Day, Hour,

+    // Minute, Second, Nanosecond.

+    //

+    EpochToEfiTime ((UINTN)EpochTime[Idx], ConvertedTime[Idx]);

+    //

+    // The times are all expressed in UTC. Consequently, they are not affected

+    // by daylight saving.

+    //

+    ConvertedTime[Idx]->TimeZone = 0;

+    ConvertedTime[Idx]->Daylight = 0;

+    //

+    // Clear the padding fields.

+    //

+    ConvertedTime[Idx]->Pad1 = 0;

+    ConvertedTime[Idx]->Pad2 = 0;

+  }

+

+  //

+  // Set the attributes.

+  //

+  switch (FuseAttr->Mode & VIRTIO_FS_FUSE_MODE_TYPE_MASK) {

+  case VIRTIO_FS_FUSE_MODE_TYPE_DIR:

+    FileInfo->Attribute = EFI_FILE_DIRECTORY;

+    break;

+  case VIRTIO_FS_FUSE_MODE_TYPE_REG:

+    FileInfo->Attribute = 0;

+    break;

+  default:

+    //

+    // Other file types are not supported.

+    //

+    return EFI_UNSUPPORTED;

+  }

+  //

+  // Report the regular file or directory as read-only if all classes lack

+  // write permission.

+  //

+  if ((FuseAttr->Mode & (VIRTIO_FS_FUSE_MODE_PERM_WUSR |

+                         VIRTIO_FS_FUSE_MODE_PERM_WGRP |

+                         VIRTIO_FS_FUSE_MODE_PERM_WOTH)) == 0) {

+    FileInfo->Attribute |= EFI_FILE_READ_ONLY;

+  }

+

+  //

+  // A hard link count greater than 1 is not supported for regular files.

+  //

+  if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) == 0 && FuseAttr->Nlink > 1) {

+    return EFI_UNSUPPORTED;

+  }

+

+  return EFI_SUCCESS;

+}

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index 795cf4ee5d..6cc5257bab 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -11,6 +11,7 @@
 #define VIRTIO_FS_DXE_H_

 

 #include <Base.h>                      // SIGNATURE_64()

+#include <Guid/FileInfo.h>             // EFI_FILE_INFO

 #include <IndustryStandard/VirtioFs.h> // VIRTIO_FS_TAG_BYTES

 #include <Library/DebugLib.h>          // CR()

 #include <Protocol/SimpleFileSystem.h> // EFI_SIMPLE_FILE_SYSTEM_PROTOCOL

@@ -225,6 +226,12 @@ VirtioFsAppendPath (
      OUT BOOLEAN *RootEscape

   );

 

+EFI_STATUS

+VirtioFsFuseAttrToEfiFileInfo (

+  IN     VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE *FuseAttr,

+     OUT EFI_FILE_INFO                      *FileInfo

+  );

+

 //

 // Wrapper functions for FUSE commands (primitives).

 //

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
index b942baa4a7..7d72721884 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
@@ -77,6 +77,7 @@
   ENTRY_POINT                           = VirtioFsEntryPoint

 

 [Packages]

+  EmbeddedPkg/EmbeddedPkg.dec

   MdePkg/MdePkg.dec

   OvmfPkg/OvmfPkg.dec

 

@@ -110,6 +111,7 @@
   BaseMemoryLib

   DebugLib

   MemoryAllocationLib

+  TimeBaseLib

   UefiBootServicesTableLib

   UefiDriverEntryPoint

   VirtioLib