mkjournal.c revision cdaf1fa78f6d63457eb5337c14b23e567d1346a7 
1/*
2 * mkjournal.c --- make a journal for a filesystem
3 *
4 * Copyright (C) 2000 Theodore Ts'o.
5 *
6 * %Begin-Header%
7 * This file may be redistributed under the terms of the GNU Public
8 * License.
9 * %End-Header%
10 */
11
12#include <stdio.h>
13#include <string.h>
14#if HAVE_UNISTD_H
15#include <unistd.h>
16#endif
17#if HAVE_ERRNO_H
18#include <errno.h>
19#endif
20#include <fcntl.h>
21#include <time.h>
22#if HAVE_SYS_STAT_H
23#include <sys/stat.h>
24#endif
25#if HAVE_SYS_TYPES_H
26#include <sys/types.h>
27#endif
28#if HAVE_NETINET_IN_H
29#include <netinet/in.h>
30#endif
31
32#if EXT2_FLAT_INCLUDES
33#include "ext2_fs.h"
34#else
35#include <linux/ext2_fs.h>
36#endif
37
38#include "e2p/e2p.h"
39#include "ext2fs.h"
40#include "jfs_user.h"
41
42static void init_journal_superblock(journal_superblock_t *jsb,
43				    __u32 blocksize, __u32 size, int flags)
44{
45	memset (jsb, 0, sizeof(*jsb));
46
47	jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
48	if (flags & EXT2_MKJOURNAL_V1_SUPER)
49		jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
50	else
51		jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
52	jsb->s_blocksize = htonl(blocksize);
53	jsb->s_maxlen = htonl(size);
54	jsb->s_first = htonl(1);
55	jsb->s_sequence = htonl(1);
56}
57
58/*
59 * This function writes a journal using POSIX routines.  It is used
60 * for creating external journals and creating journals on live
61 * filesystems.
62 */
63static errcode_t write_journal_file(ext2_filsys fs, char *device,
64				    blk_t size, int flags)
65{
66	errcode_t	retval;
67	char		*buf = 0;
68	journal_superblock_t	jsb;
69	int		i, fd, ret_size;
70
71	init_journal_superblock(&jsb, fs->blocksize, size, flags);
72
73	/* Create a block buffer */
74	buf = malloc(fs->blocksize);
75	if (!buf)
76		return ENOMEM;
77
78	/* Open the device */
79	if ((fd = open(device, O_WRONLY)) < 0) {
80		retval = errno;
81		goto errout;
82	}
83
84	/* Write the superblock out */
85	memset(buf, 0, fs->blocksize);
86	memcpy(buf, &jsb, sizeof(jsb));
87	retval = EXT2_ET_SHORT_WRITE;
88	ret_size = write(fd, buf, fs->blocksize);
89	if (ret_size < 0) {
90		errno = retval;
91		goto errout;
92	}
93	if (ret_size != fs->blocksize)
94		goto errout;
95	memset(buf, 0, fs->blocksize);
96
97	for (i = 1; i < size; i++) {
98		ret_size = write(fd, buf, fs->blocksize);
99		if (ret_size < 0) {
100			retval = errno;
101			goto errout;
102		}
103		if (ret_size != fs->blocksize)
104			goto errout;
105	}
106	close(fd);
107
108	retval = 0;
109errout:
110	free(buf);
111	return retval;
112}
113
114/*
115 * Helper function for creating the journal using direct I/O routines
116 */
117struct mkjournal_struct {
118	int		num_blocks;
119	int		newblocks;
120	char		*buf;
121	errcode_t	err;
122};
123
124static int mkjournal_proc(ext2_filsys		fs,
125			   blk_t		*blocknr,
126			   e2_blkcnt_t		blockcnt,
127			   blk_t		ref_block,
128			   int			ref_offset,
129			   void			*priv_data)
130{
131	struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
132	blk_t	new_blk;
133	static blk_t	last_blk = 0;
134	errcode_t	retval;
135	int		group;
136
137	if (*blocknr) {
138		last_blk = *blocknr;
139		return 0;
140	}
141	retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
142	if (retval) {
143		es->err = retval;
144		return BLOCK_ABORT;
145	}
146	if (blockcnt > 0)
147		es->num_blocks--;
148
149	es->newblocks++;
150	retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
151
152	if (blockcnt == 0)
153		memset(es->buf, 0, fs->blocksize);
154
155	if (retval) {
156		es->err = retval;
157		return BLOCK_ABORT;
158	}
159	*blocknr = new_blk;
160	ext2fs_mark_block_bitmap(fs->block_map, new_blk);
161	ext2fs_mark_bb_dirty(fs);
162	group = ext2fs_group_of_blk(fs, new_blk);
163	fs->group_desc[group].bg_free_blocks_count--;
164	fs->super->s_free_blocks_count--;
165	ext2fs_mark_super_dirty(fs);
166
167	if (es->num_blocks == 0)
168		return (BLOCK_CHANGED | BLOCK_ABORT);
169	else
170		return BLOCK_CHANGED;
171
172}
173
174/*
175 * This function creates a journal using direct I/O routines.
176 */
177static errcode_t write_journal_inode(ext2_filsys fs, ino_t journal_ino,
178				     blk_t size, int flags)
179{
180	journal_superblock_t	jsb;
181	errcode_t		retval;
182	struct ext2_inode	inode;
183	struct mkjournal_struct	es;
184	char			*buf;
185
186	init_journal_superblock(&jsb, fs->blocksize, size, flags);
187
188	if ((retval = ext2fs_read_bitmaps(fs)))
189		return retval;
190
191	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
192		return retval;
193
194	if (inode.i_blocks > 0)
195		return EEXIST;
196
197	/* Create the block buffer */
198	buf = malloc(fs->blocksize);
199	if (!buf)
200		return ENOMEM;
201
202	memset(buf, 0, fs->blocksize);
203	memcpy(buf, &jsb, sizeof(jsb));
204
205	es.num_blocks = size;
206	es.newblocks = 0;
207	es.buf = buf;
208	es.err = 0;
209
210	retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
211				       0, mkjournal_proc, &es);
212	free(buf);
213	if (es.err)
214		return es.err;
215
216	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
217		return retval;
218
219 	inode.i_size += fs->blocksize * size;
220	inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
221	inode.i_mtime = inode.i_ctime = time(0);
222	inode.i_links_count = 1;
223	inode.i_mode = LINUX_S_IFREG | 0600;
224
225	if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
226		return retval;
227
228	return 0;
229}
230
231/*
232 * This function adds a journal device to a filesystem
233 */
234errcode_t ext2fs_add_journal_device(ext2_filsys fs, char *device,
235				    blk_t size, int flags)
236{
237	struct stat	st;
238	errcode_t	retval;
239	blk_t		dev_size;
240
241	/* Make sure the device exists and is a block device */
242	if (stat(device, &st) < 0)
243		return errno;
244	if (!S_ISBLK(st.st_mode))
245		return EXT2_JOURNAL_NOT_BLOCK;	/* Must be a block device */
246
247	/* Get the size of the device */
248	if ((retval = ext2fs_get_device_size(device, fs->blocksize,
249					     &dev_size)))
250		return retval;
251
252	if (!size)
253		size = dev_size; /* Default to the size of the device */
254	else if (size > dev_size)
255		return EINVAL;	/* Requested size bigger than device */
256
257	retval = write_journal_file(fs, device, size, flags);
258	if (retval)
259		return retval;
260
261	fs->super->s_journal_inum = 0;
262	fs->super->s_journal_dev = st.st_rdev;
263	memset(fs->super->s_journal_uuid, 0,
264	       sizeof(fs->super->s_journal_uuid));
265	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
266	ext2fs_mark_super_dirty(fs);
267	return 0;
268}
269
270/*
271 * This function adds a journal inode to a filesystem, using either
272 * POSIX routines if the filesystem is mounted, or using direct I/O
273 * functions if it is not.
274 */
275errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
276{
277	errcode_t		retval;
278	ino_t			journal_ino;
279	struct stat		st;
280	char			jfile[1024];
281	int			fd, mount_flags;
282
283	if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
284					       jfile, sizeof(jfile)-10)))
285		return retval;
286
287	if (mount_flags & EXT2_MF_MOUNTED) {
288		strcat(jfile, "/.journal");
289
290		/* Create the journal file */
291		if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
292			return errno;
293		close(fd);
294
295		if ((retval = write_journal_file(fs, jfile, size, flags)))
296			return retval;
297
298		/* Get inode number of the journal file */
299		if (stat(jfile, &st) < 0)
300			return errno;
301
302		if ((retval = fsetflags(jfile,
303					EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL)))
304			return retval;
305
306		journal_ino = st.st_ino;
307	} else {
308		journal_ino = EXT2_JOURNAL_INO;
309		if ((retval = write_journal_inode(fs, journal_ino,
310						  size, flags)))
311			return retval;
312	}
313
314	fs->super->s_journal_inum = journal_ino;
315	fs->super->s_journal_dev = 0;
316	memset(fs->super->s_journal_uuid, 0,
317	       sizeof(fs->super->s_journal_uuid));
318	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
319
320	ext2fs_mark_super_dirty(fs);
321	return 0;
322}
323
324#ifdef DEBUG
325main(int argc, char **argv)
326{
327	errcode_t	retval;
328	char		*device_name;
329	ext2_filsys 	fs;
330
331	if (argc < 2) {
332		fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
333		exit(1);
334	}
335	device_name = argv[1];
336
337	retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
338			      unix_io_manager, &fs);
339	if (retval) {
340		com_err(argv[0], retval, "while opening %s", device_name);
341		exit(1);
342	}
343
344	retval = ext2fs_add_journal_inode(fs, 1024);
345	if (retval) {
346		com_err(argv[0], retval, "while adding journal to %s",
347			device_name);
348		exit(1);
349	}
350	retval = ext2fs_flush(fs);
351	if (retval) {
352		printf("Warning, had trouble writing out superblocks.\n");
353	}
354	ext2fs_close(fs);
355	exit(0);
356
357}
358#endif
359