xref: /openbmc/linux/fs/ntfs/usnjrnl.c (revision 9cfc5c90)
1 /*
2  * usnjrnl.h - NTFS kernel transaction log ($UsnJrnl) handling.  Part of the
3  *	       Linux-NTFS project.
4  *
5  * Copyright (c) 2005 Anton Altaparmakov
6  *
7  * This program/include file is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as published
9  * by the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program/include file is distributed in the hope that it will be
13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program (in the main directory of the Linux-NTFS
19  * distribution in the file COPYING); if not, write to the Free Software
20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21  */
22 
23 #ifdef NTFS_RW
24 
25 #include <linux/fs.h>
26 #include <linux/highmem.h>
27 #include <linux/mm.h>
28 
29 #include "aops.h"
30 #include "debug.h"
31 #include "endian.h"
32 #include "time.h"
33 #include "types.h"
34 #include "usnjrnl.h"
35 #include "volume.h"
36 
37 /**
38  * ntfs_stamp_usnjrnl - stamp the transaction log ($UsnJrnl) on an ntfs volume
39  * @vol:	ntfs volume on which to stamp the transaction log
40  *
41  * Stamp the transaction log ($UsnJrnl) on the ntfs volume @vol and return
42  * 'true' on success and 'false' on error.
43  *
44  * This function assumes that the transaction log has already been loaded and
45  * consistency checked by a call to fs/ntfs/super.c::load_and_init_usnjrnl().
46  */
47 bool ntfs_stamp_usnjrnl(ntfs_volume *vol)
48 {
49 	ntfs_debug("Entering.");
50 	if (likely(!NVolUsnJrnlStamped(vol))) {
51 		sle64 stamp;
52 		struct page *page;
53 		USN_HEADER *uh;
54 
55 		page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
56 		if (IS_ERR(page)) {
57 			ntfs_error(vol->sb, "Failed to read from "
58 					"$UsnJrnl/$DATA/$Max attribute.");
59 			return false;
60 		}
61 		uh = (USN_HEADER*)page_address(page);
62 		stamp = get_current_ntfs_time();
63 		ntfs_debug("Stamping transaction log ($UsnJrnl): old "
64 				"journal_id 0x%llx, old lowest_valid_usn "
65 				"0x%llx, new journal_id 0x%llx, new "
66 				"lowest_valid_usn 0x%llx.",
67 				(long long)sle64_to_cpu(uh->journal_id),
68 				(long long)sle64_to_cpu(uh->lowest_valid_usn),
69 				(long long)sle64_to_cpu(stamp),
70 				i_size_read(vol->usnjrnl_j_ino));
71 		uh->lowest_valid_usn =
72 				cpu_to_sle64(i_size_read(vol->usnjrnl_j_ino));
73 		uh->journal_id = stamp;
74 		flush_dcache_page(page);
75 		set_page_dirty(page);
76 		ntfs_unmap_page(page);
77 		/* Set the flag so we do not have to do it again on remount. */
78 		NVolSetUsnJrnlStamped(vol);
79 	}
80 	ntfs_debug("Done.");
81 	return true;
82 }
83 
84 #endif /* NTFS_RW */
85