FatPkg/EnhancedFatDxe/Delete.c

   1 /** @file
   2   Function that deletes a file.
   3
   4 Copyright (c) 2005 - 2013, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials are licensed and made available
   6 under the terms and conditions of the BSD License which accompanies this
   7 distribution. The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13
  14 **/
  15
  16 #include "Fat.h"
  17
  18 /**
  19
  20   Deletes the file & Closes the file handle.
  21
  22   @param  FHand                    - Handle to the file to delete.
  23
  24   @retval EFI_SUCCESS              - Delete the file successfully.
  25   @retval EFI_WARN_DELETE_FAILURE  - Fail to delete the file.
  26
  27 **/
  28 EFI_STATUS
  29 EFIAPI
  30 FatDelete (
  31   IN EFI_FILE_PROTOCOL  *FHand
  32   )
  33 {
  34   FAT_IFILE   *IFile;
  35   FAT_OFILE   *OFile;
  36   FAT_DIRENT  *DirEnt;
  37   EFI_STATUS  Status;
  38   UINTN       Round;
  39
  40   IFile = IFILE_FROM_FHAND (FHand);
  41   OFile = IFile->OFile;
  42
  43   FatWaitNonblockingTask (IFile);
  44
  45   //
  46   // Lock the volume
  47   //
  48   FatAcquireLock ();
  49
  50   //
  51   // If the file is read-only, then don't delete it
  52   //
  53   if (IFile->ReadOnly) {
  54     Status = EFI_WRITE_PROTECTED;
  55     goto Done;
  56   }
  57   //
  58   // If the file is the root dir, then don't delete it
  59   //
  60   if (OFile->Parent == NULL) {
  61     Status = EFI_ACCESS_DENIED;
  62     goto Done;
  63   }
  64   //
  65   // If the file has a permanant error, skip the delete
  66   //
  67   Status = OFile->Error;
  68   if (!EFI_ERROR (Status)) {
  69     //
  70     // If this is a directory, make sure it's empty before
  71     // allowing it to be deleted
  72     //
  73     if (OFile->ODir != NULL) {
  74       //
  75       // We do not allow to delete nonempty directory
  76       //
  77       FatResetODirCursor (OFile);
  78       for (Round = 0; Round < 3; Round++) {
  79         Status = FatGetNextDirEnt (OFile, &DirEnt);
  80         if ((EFI_ERROR (Status)) ||
  81             ((Round < 2) && (DirEnt == NULL || !FatIsDotDirEnt (DirEnt))) ||
  82             ((Round == 2) && (DirEnt != NULL))
  83             ) {
  84           Status = EFI_ACCESS_DENIED;
  85           goto Done;
  86         }
  87       }
  88     }
  89     //
  90     // Return the file's space by setting its size to 0
  91     //
  92     FatTruncateOFile (OFile, 0);
  93     //
  94     // Free the directory entry for this file
  95     //
  96     Status = FatRemoveDirEnt (OFile->Parent, OFile->DirEnt);
  97     if (EFI_ERROR (Status)) {
  98       goto Done;
  99     }
 100     //
 101     // Set a permanent error for this OFile in case there
 102     // are still opened IFiles attached
 103     //
 104     OFile->Error = EFI_NOT_FOUND;
 105   } else if (OFile->Error == EFI_NOT_FOUND) {
 106     Status = EFI_SUCCESS;
 107   }
 108
 109 Done:
 110   //
 111   // Always close the handle
 112   //
 113   FatIFileClose (IFile);
 114   //
 115   // Done
 116   //
 117   Status = FatCleanupVolume (OFile->Volume, NULL, Status, NULL);
 118   FatReleaseLock ();
 119
 120   if (EFI_ERROR (Status)) {
 121     Status = EFI_WARN_DELETE_FAILURE;
 122   }
 123
 124   return Status;
 125 }