fs/freevxfs/vxfs_immed.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2000-2001 Christoph Hellwig.
   4  */
   5
   6 /*
   7  * Veritas filesystem driver - support for 'immed' inodes.
   8  */
   9 #include <linux/fs.h>
  10 #include <linux/pagemap.h>
  11
  12 #include "vxfs.h"
  13 #include "vxfs_extern.h"
  14 #include "vxfs_inode.h"
  15
  16
  17 static int      vxfs_immed_read_folio(struct file *, struct folio *);
  18
  19 /*
  20  * Address space operations for immed files and directories.
  21  */
  22 const struct address_space_operations vxfs_immed_aops = {
  23         .read_folio =           vxfs_immed_read_folio,
  24 };
  25
  26 /**
  27  * vxfs_immed_read_folio - read part of an immed inode into pagecache
  28  * @file:       file context (unused)
  29  * @folio:      folio to fill in.
  30  *
  31  * Description:
  32  *   vxfs_immed_read_folio reads a part of the immed area of the
  33  *   file that hosts @pp into the pagecache.
  34  *
  35  * Returns:
  36  *   Zero on success, else a negative error code.
  37  *
  38  * Locking status:
  39  *   @folio is locked and will be unlocked.
  40  */
  41 static int
  42 vxfs_immed_read_folio(struct file *fp, struct folio *folio)
  43 {
  44         struct page *pp = &folio->page;
  45         struct vxfs_inode_info  *vip = VXFS_INO(pp->mapping->host);
  46         u_int64_t       offset = (u_int64_t)pp->index << PAGE_SHIFT;
  47         caddr_t         kaddr;
  48
  49         kaddr = kmap(pp);
  50         memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_SIZE);
  51         kunmap(pp);
  52
  53         flush_dcache_page(pp);
  54         SetPageUptodate(pp);
  55         unlock_page(pp);
  56
  57         return 0;
  58 }