fs/freevxfs/vxfs_immed.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (c) 2000-2001 Christoph Hellwig.
0004  */
0005
0006 /*
0007  * Veritas filesystem driver - support for 'immed' inodes.
0008  */
0009 #include <linux/fs.h>
0010 #include <linux/pagemap.h>
0011
0012 #include "vxfs.h"
0013 #include "vxfs_extern.h"
0014 #include "vxfs_inode.h"
0015
0016 /**
0017  * vxfs_immed_read_folio - read part of an immed inode into pagecache
0018  * @file:   file context (unused)
0019  * @folio:  folio to fill in.
0020  *
0021  * Description:
0022  *   vxfs_immed_read_folio reads a part of the immed area of the
0023  *   file that hosts @folio into the pagecache.
0024  *
0025  * Returns:
0026  *   Zero on success, else a negative error code.
0027  *
0028  * Locking status:
0029  *   @folio is locked and will be unlocked.
0030  */
0031 static int vxfs_immed_read_folio(struct file *fp, struct folio *folio)
0032 {
0033     struct vxfs_inode_info *vip = VXFS_INO(folio->mapping->host);
0034     void *src = vip->vii_immed.vi_immed + folio_pos(folio);
0035     unsigned long i;
0036
0037     for (i = 0; i < folio_nr_pages(folio); i++) {
0038         memcpy_to_page(folio_page(folio, i), 0, src, PAGE_SIZE);
0039         src += PAGE_SIZE;
0040     }
0041
0042     folio_mark_uptodate(folio);
0043     folio_unlock(folio);
0044
0045     return 0;
0046 }
0047
0048 /*
0049  * Address space operations for immed files and directories.
0050  */
0051 const struct address_space_operations vxfs_immed_aops = {
0052     .read_folio =   vxfs_immed_read_folio,
0053 };