mkjournal.c revision b23520d0501095dee715d0829c365933c216e612 
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_SYS_IOCTL_H
29#include <sys/ioctl.h>
30#endif
31#if HAVE_NETINET_IN_H
32#include <netinet/in.h>
33#endif
34
35#include "ext2_fs.h"
36#include "e2p/e2p.h"
37#include "ext2fs.h"
38#include "jfs_user.h"
39
40/*
41 * This function automatically sets up the journal superblock and
42 * returns it as an allocated block.
43 */
44errcode_t ext2fs_create_journal_superblock(ext2_filsys fs,
45					   __u32 size, int flags,
46					   char  **ret_jsb)
47{
48	errcode_t		retval;
49	journal_superblock_t	*jsb;
50
51	if (size < 1024)
52		return EXT2_ET_JOURNAL_TOO_SMALL;
53
54	if ((retval = ext2fs_get_mem(fs->blocksize, (void **) &jsb)))
55		return retval;
56
57	memset (jsb, 0, fs->blocksize);
58
59	jsb->s_header.h_magic = htonl(JFS_MAGIC_NUMBER);
60	if (flags & EXT2_MKJOURNAL_V1_SUPER)
61		jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V1);
62	else
63		jsb->s_header.h_blocktype = htonl(JFS_SUPERBLOCK_V2);
64	jsb->s_blocksize = htonl(fs->blocksize);
65	jsb->s_maxlen = htonl(size);
66	jsb->s_nr_users = htonl(1);
67	jsb->s_first = htonl(1);
68	jsb->s_sequence = htonl(1);
69	memcpy(jsb->s_uuid, fs->super->s_uuid, sizeof(fs->super->s_uuid));
70	/*
71	 * If we're creating an external journal device, we need to
72	 * adjust these fields.
73	 */
74	if (fs->super->s_feature_incompat &
75	    EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
76		jsb->s_nr_users = 0;
77
78	*ret_jsb = (char *) jsb;
79	return 0;
80}
81
82/*
83 * This function writes a journal using POSIX routines.  It is used
84 * for creating external journals and creating journals on live
85 * filesystems.
86 */
87static errcode_t write_journal_file(ext2_filsys fs, char *filename,
88				    blk_t size, int flags)
89{
90	errcode_t	retval;
91	char		*buf = 0;
92	int		i, fd, ret_size;
93
94	if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
95		return retval;
96
97	/* Open the device or journal file */
98	if ((fd = open(filename, O_WRONLY)) < 0) {
99		retval = errno;
100		goto errout;
101	}
102
103	/* Write the superblock out */
104	retval = EXT2_ET_SHORT_WRITE;
105	ret_size = write(fd, buf, fs->blocksize);
106	if (ret_size < 0) {
107		retval = errno;
108		goto errout;
109	}
110	if (ret_size != fs->blocksize)
111		goto errout;
112	memset(buf, 0, fs->blocksize);
113
114	for (i = 1; i < size; i++) {
115		ret_size = write(fd, buf, fs->blocksize);
116		if (ret_size < 0) {
117			retval = errno;
118			goto errout;
119		}
120		if (ret_size != fs->blocksize)
121			goto errout;
122	}
123	close(fd);
124
125	retval = 0;
126errout:
127	ext2fs_free_mem((void **) &buf);
128	return retval;
129}
130
131/*
132 * Helper function for creating the journal using direct I/O routines
133 */
134struct mkjournal_struct {
135	int		num_blocks;
136	int		newblocks;
137	char		*buf;
138	errcode_t	err;
139};
140
141static int mkjournal_proc(ext2_filsys		fs,
142			   blk_t		*blocknr,
143			   e2_blkcnt_t		blockcnt,
144			   blk_t		ref_block,
145			   int			ref_offset,
146			   void			*priv_data)
147{
148	struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
149	blk_t	new_blk;
150	static blk_t	last_blk = 0;
151	errcode_t	retval;
152	int		group;
153
154	if (*blocknr) {
155		last_blk = *blocknr;
156		return 0;
157	}
158	retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
159	if (retval) {
160		es->err = retval;
161		return BLOCK_ABORT;
162	}
163	if (blockcnt > 0)
164		es->num_blocks--;
165
166	es->newblocks++;
167	retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
168
169	if (blockcnt == 0)
170		memset(es->buf, 0, fs->blocksize);
171
172	if (retval) {
173		es->err = retval;
174		return BLOCK_ABORT;
175	}
176	*blocknr = new_blk;
177	ext2fs_mark_block_bitmap(fs->block_map, new_blk);
178	ext2fs_mark_bb_dirty(fs);
179	group = ext2fs_group_of_blk(fs, new_blk);
180	fs->group_desc[group].bg_free_blocks_count--;
181	fs->super->s_free_blocks_count--;
182	ext2fs_mark_super_dirty(fs);
183
184	if (es->num_blocks == 0)
185		return (BLOCK_CHANGED | BLOCK_ABORT);
186	else
187		return BLOCK_CHANGED;
188
189}
190
191/*
192 * This function creates a journal using direct I/O routines.
193 */
194static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
195				     blk_t size, int flags)
196{
197	char			*buf;
198	errcode_t		retval;
199	struct ext2_inode	inode;
200	struct mkjournal_struct	es;
201
202	if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
203		return retval;
204
205	if ((retval = ext2fs_read_bitmaps(fs)))
206		return retval;
207
208	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
209		return retval;
210
211	if (inode.i_blocks > 0)
212		return EEXIST;
213
214	es.num_blocks = size;
215	es.newblocks = 0;
216	es.buf = buf;
217	es.err = 0;
218
219	retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
220				       0, mkjournal_proc, &es);
221	if (es.err) {
222		retval = es.err;
223		goto errout;
224	}
225
226	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
227		goto errout;
228
229 	inode.i_size += fs->blocksize * size;
230	inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
231	inode.i_mtime = inode.i_ctime = time(0);
232	inode.i_links_count = 1;
233	inode.i_mode = LINUX_S_IFREG | 0600;
234
235	if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
236		goto errout;
237	retval = 0;
238
239errout:
240	ext2fs_free_mem((void **) &buf);
241	return retval;
242}
243
244/*
245 * This function adds a journal device to a filesystem
246 */
247errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
248{
249	struct stat	st;
250	errcode_t	retval;
251	char		buf[1024];
252	journal_superblock_t	*jsb;
253	int		i;
254	__u32		nr_users;
255
256	/* Make sure the device exists and is a block device */
257	if (stat(journal_dev->device_name, &st) < 0)
258		return errno;
259
260	if (!S_ISBLK(st.st_mode))
261		return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
262
263	/* Get the journal superblock */
264	if ((retval = io_channel_read_blk(journal_dev->io, 1, -1024, buf)))
265		return retval;
266
267	jsb = (journal_superblock_t *) buf;
268	if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
269	    (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
270		return EXT2_ET_NO_JOURNAL_SB;
271
272	if (ntohl(jsb->s_blocksize) != fs->blocksize)
273		return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
274
275	/* Check and see if this filesystem has already been added */
276	nr_users = ntohl(jsb->s_nr_users);
277	for (i=0; i < nr_users; i++) {
278		if (memcmp(fs->super->s_uuid,
279			   &jsb->s_users[i*16], 16) == 0)
280			break;
281	}
282	if (i >= nr_users) {
283		memcpy(&jsb->s_users[nr_users*16],
284		       fs->super->s_uuid, 16);
285		jsb->s_nr_users = htonl(nr_users+1);
286	}
287
288	/* Writeback the journal superblock */
289	if ((retval = io_channel_write_blk(journal_dev->io, 1, -1024, buf)))
290		return retval;
291
292	fs->super->s_journal_inum = 0;
293	fs->super->s_journal_dev = st.st_rdev;
294	memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
295	       sizeof(fs->super->s_journal_uuid));
296	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
297	ext2fs_mark_super_dirty(fs);
298	return 0;
299}
300
301/*
302 * This function adds a journal inode to a filesystem, using either
303 * POSIX routines if the filesystem is mounted, or using direct I/O
304 * functions if it is not.
305 */
306errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
307{
308	errcode_t		retval;
309	ext2_ino_t		journal_ino;
310	struct stat		st;
311	char			jfile[1024];
312	int			fd, mount_flags, f;
313
314	if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
315					       jfile, sizeof(jfile)-10)))
316		return retval;
317
318	if (mount_flags & EXT2_MF_MOUNTED) {
319		strcat(jfile, "/.journal");
320
321		/* Create the journal file */
322		if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
323			return errno;
324
325		if ((retval = write_journal_file(fs, jfile, size, flags)))
326			goto errout;
327
328		/* Get inode number of the journal file */
329		if (fstat(fd, &st) < 0)
330			goto errout;
331
332#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
333		retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
334#else
335#if HAVE_EXT2_IOCTLS
336		f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;;
337		retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
338#endif
339#endif
340		if (retval)
341			goto errout;
342
343		close(fd);
344		journal_ino = st.st_ino;
345	} else {
346		journal_ino = EXT2_JOURNAL_INO;
347		if ((retval = write_journal_inode(fs, journal_ino,
348						  size, flags)))
349			return retval;
350	}
351
352	fs->super->s_journal_inum = journal_ino;
353	fs->super->s_journal_dev = 0;
354	memset(fs->super->s_journal_uuid, 0,
355	       sizeof(fs->super->s_journal_uuid));
356	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
357
358	ext2fs_mark_super_dirty(fs);
359	return 0;
360errout:
361	close(fd);
362	return retval;
363}
364
365#ifdef DEBUG
366main(int argc, char **argv)
367{
368	errcode_t	retval;
369	char		*device_name;
370	ext2_filsys 	fs;
371
372	if (argc < 2) {
373		fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
374		exit(1);
375	}
376	device_name = argv[1];
377
378	retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
379			      unix_io_manager, &fs);
380	if (retval) {
381		com_err(argv[0], retval, "while opening %s", device_name);
382		exit(1);
383	}
384
385	retval = ext2fs_add_journal_inode(fs, 1024);
386	if (retval) {
387		com_err(argv[0], retval, "while adding journal to %s",
388			device_name);
389		exit(1);
390	}
391	retval = ext2fs_flush(fs);
392	if (retval) {
393		printf("Warning, had trouble writing out superblocks.\n");
394	}
395	ext2fs_close(fs);
396	exit(0);
397
398}
399#endif
400