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  * vxfs_immed_read_folio - read part of an immed inode into pagecache
  18  * @fp:         file context (unused)
  19  * @folio:      folio to fill in.
  20  *
  21  * Description:
  22  *   vxfs_immed_read_folio reads a part of the immed area of the
  23  *   file that hosts @folio into the pagecache.
  24  *
  25  * Returns:
  26  *   Zero on success, else a negative error code.
  27  *
  28  * Locking status:
  29  *   @folio is locked and will be unlocked.
  30  */
  31 static int vxfs_immed_read_folio(struct file *fp, struct folio *folio)
  32 {
  33         struct vxfs_inode_info *vip = VXFS_INO(folio->mapping->host);
  34         void *src = vip->vii_immed.vi_immed + folio_pos(folio);
  35         unsigned long i;
  36
  37         for (i = 0; i < folio_nr_pages(folio); i++) {
  38                 memcpy_to_page(folio_page(folio, i), 0, src, PAGE_SIZE);
  39                 src += PAGE_SIZE;
  40         }
  41
  42         folio_mark_uptodate(folio);
  43         folio_unlock(folio);
  44
  45         return 0;
  46 }
  47
  48 /*
  49  * Address space operations for immed files and directories.
  50  */
  51 const struct address_space_operations vxfs_immed_aops = {
  52         .read_folio =   vxfs_immed_read_folio,
  53 };