1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * usnjrnl.h - NTFS kernel transaction log ($UsnJrnl) handling.  Part of the
4  *	       Linux-NTFS project.
5  *
6  * Copyright (c) 2005 Anton Altaparmakov
7  */
8 
9 #ifdef NTFS_RW
10 
11 #include <linux/fs.h>
12 #include <linux/highmem.h>
13 #include <linux/mm.h>
14 
15 #include "aops.h"
16 #include "debug.h"
17 #include "endian.h"
18 #include "time.h"
19 #include "types.h"
20 #include "usnjrnl.h"
21 #include "volume.h"
22 
23 /**
24  * ntfs_stamp_usnjrnl - stamp the transaction log ($UsnJrnl) on an ntfs volume
25  * @vol:	ntfs volume on which to stamp the transaction log
26  *
27  * Stamp the transaction log ($UsnJrnl) on the ntfs volume @vol and return
28  * 'true' on success and 'false' on error.
29  *
30  * This function assumes that the transaction log has already been loaded and
31  * consistency checked by a call to fs/ntfs/super.c::load_and_init_usnjrnl().
32  */
ntfs_stamp_usnjrnl(ntfs_volume * vol)33 bool ntfs_stamp_usnjrnl(ntfs_volume *vol)
34 {
35 	ntfs_debug("Entering.");
36 	if (likely(!NVolUsnJrnlStamped(vol))) {
37 		sle64 stamp;
38 		struct page *page;
39 		USN_HEADER *uh;
40 
41 		page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
42 		if (IS_ERR(page)) {
43 			ntfs_error(vol->sb, "Failed to read from "
44 					"$UsnJrnl/$DATA/$Max attribute.");
45 			return false;
46 		}
47 		uh = (USN_HEADER*)page_address(page);
48 		stamp = get_current_ntfs_time();
49 		ntfs_debug("Stamping transaction log ($UsnJrnl): old "
50 				"journal_id 0x%llx, old lowest_valid_usn "
51 				"0x%llx, new journal_id 0x%llx, new "
52 				"lowest_valid_usn 0x%llx.",
53 				(long long)sle64_to_cpu(uh->journal_id),
54 				(long long)sle64_to_cpu(uh->lowest_valid_usn),
55 				(long long)sle64_to_cpu(stamp),
56 				i_size_read(vol->usnjrnl_j_ino));
57 		uh->lowest_valid_usn =
58 				cpu_to_sle64(i_size_read(vol->usnjrnl_j_ino));
59 		uh->journal_id = stamp;
60 		flush_dcache_page(page);
61 		set_page_dirty(page);
62 		ntfs_unmap_page(page);
63 		/* Set the flag so we do not have to do it again on remount. */
64 		NVolSetUsnJrnlStamped(vol);
65 	}
66 	ntfs_debug("Done.");
67 	return true;
68 }
69 
70 #endif /* NTFS_RW */
71