mkjournal.c revision 5bc28df0fa2544a08b65d9091fdc9fb23bdbce68 
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		if (fs->blocksize == 1024)
78			jsb->s_first = htonl(3);
79		else
80			jsb->s_first = htonl(2);
81	}
82
83	*ret_jsb = (char *) jsb;
84	return 0;
85}
86
87/*
88 * This function writes a journal using POSIX routines.  It is used
89 * for creating external journals and creating journals on live
90 * filesystems.
91 */
92static errcode_t write_journal_file(ext2_filsys fs, char *filename,
93				    blk_t size, int flags)
94{
95	errcode_t	retval;
96	char		*buf = 0;
97	int		i, fd, ret_size;
98
99	if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
100		return retval;
101
102	/* Open the device or journal file */
103	if ((fd = open(filename, O_WRONLY)) < 0) {
104		retval = errno;
105		goto errout;
106	}
107
108	/* Write the superblock out */
109	retval = EXT2_ET_SHORT_WRITE;
110	ret_size = write(fd, buf, fs->blocksize);
111	if (ret_size < 0) {
112		retval = errno;
113		goto errout;
114	}
115	if (ret_size != fs->blocksize)
116		goto errout;
117	memset(buf, 0, fs->blocksize);
118
119	for (i = 1; i < size; i++) {
120		ret_size = write(fd, buf, fs->blocksize);
121		if (ret_size < 0) {
122			retval = errno;
123			goto errout;
124		}
125		if (ret_size != fs->blocksize)
126			goto errout;
127	}
128	close(fd);
129
130	retval = 0;
131errout:
132	ext2fs_free_mem((void **) &buf);
133	return retval;
134}
135
136/*
137 * Helper function for creating the journal using direct I/O routines
138 */
139struct mkjournal_struct {
140	int		num_blocks;
141	int		newblocks;
142	char		*buf;
143	errcode_t	err;
144};
145
146static int mkjournal_proc(ext2_filsys		fs,
147			   blk_t		*blocknr,
148			   e2_blkcnt_t		blockcnt,
149			   blk_t		ref_block,
150			   int			ref_offset,
151			   void			*priv_data)
152{
153	struct mkjournal_struct *es = (struct mkjournal_struct *) priv_data;
154	blk_t	new_blk;
155	static blk_t	last_blk = 0;
156	errcode_t	retval;
157	int		group;
158
159	if (*blocknr) {
160		last_blk = *blocknr;
161		return 0;
162	}
163	retval = ext2fs_new_block(fs, last_blk, 0, &new_blk);
164	if (retval) {
165		es->err = retval;
166		return BLOCK_ABORT;
167	}
168	if (blockcnt > 0)
169		es->num_blocks--;
170
171	es->newblocks++;
172	retval = io_channel_write_blk(fs->io, new_blk, 1, es->buf);
173
174	if (blockcnt == 0)
175		memset(es->buf, 0, fs->blocksize);
176
177	if (retval) {
178		es->err = retval;
179		return BLOCK_ABORT;
180	}
181	*blocknr = new_blk;
182	last_blk = new_blk;
183	ext2fs_mark_block_bitmap(fs->block_map, new_blk);
184	ext2fs_mark_bb_dirty(fs);
185	group = ext2fs_group_of_blk(fs, new_blk);
186	fs->group_desc[group].bg_free_blocks_count--;
187	fs->super->s_free_blocks_count--;
188	ext2fs_mark_super_dirty(fs);
189
190	if (es->num_blocks == 0)
191		return (BLOCK_CHANGED | BLOCK_ABORT);
192	else
193		return BLOCK_CHANGED;
194
195}
196
197/*
198 * This function creates a journal using direct I/O routines.
199 */
200static errcode_t write_journal_inode(ext2_filsys fs, ext2_ino_t journal_ino,
201				     blk_t size, int flags)
202{
203	char			*buf;
204	errcode_t		retval;
205	struct ext2_inode	inode;
206	struct mkjournal_struct	es;
207
208	if ((retval = ext2fs_create_journal_superblock(fs, size, flags, &buf)))
209		return retval;
210
211	if ((retval = ext2fs_read_bitmaps(fs)))
212		return retval;
213
214	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
215		return retval;
216
217	if (inode.i_blocks > 0)
218		return EEXIST;
219
220	es.num_blocks = size;
221	es.newblocks = 0;
222	es.buf = buf;
223	es.err = 0;
224
225	retval = ext2fs_block_iterate2(fs, journal_ino, BLOCK_FLAG_APPEND,
226				       0, mkjournal_proc, &es);
227	if (es.err) {
228		retval = es.err;
229		goto errout;
230	}
231
232	if ((retval = ext2fs_read_inode(fs, journal_ino, &inode)))
233		goto errout;
234
235 	inode.i_size += fs->blocksize * size;
236	inode.i_blocks += (fs->blocksize / 512) * es.newblocks;
237	inode.i_mtime = inode.i_ctime = time(0);
238	inode.i_links_count = 1;
239	inode.i_mode = LINUX_S_IFREG | 0600;
240
241	if ((retval = ext2fs_write_inode(fs, journal_ino, &inode)))
242		goto errout;
243	retval = 0;
244
245errout:
246	ext2fs_free_mem((void **) &buf);
247	return retval;
248}
249
250/*
251 * This function adds a journal device to a filesystem
252 */
253errcode_t ext2fs_add_journal_device(ext2_filsys fs, ext2_filsys journal_dev)
254{
255	struct stat	st;
256	errcode_t	retval;
257	char		buf[1024];
258	journal_superblock_t	*jsb;
259	int		i, start;
260	__u32		nr_users;
261
262	/* Make sure the device exists and is a block device */
263	if (stat(journal_dev->device_name, &st) < 0)
264		return errno;
265
266	if (!S_ISBLK(st.st_mode))
267		return EXT2_ET_JOURNAL_NOT_BLOCK; /* Must be a block device */
268
269	/* Get the journal superblock */
270	start = 1;
271	if (journal_dev->blocksize == 1024)
272		start++;
273	if ((retval = io_channel_read_blk(journal_dev->io, start, -1024, buf)))
274		return retval;
275
276	jsb = (journal_superblock_t *) buf;
277	if ((jsb->s_header.h_magic != (unsigned) ntohl(JFS_MAGIC_NUMBER)) ||
278	    (jsb->s_header.h_blocktype != (unsigned) ntohl(JFS_SUPERBLOCK_V2)))
279		return EXT2_ET_NO_JOURNAL_SB;
280
281	if (ntohl(jsb->s_blocksize) != fs->blocksize)
282		return EXT2_ET_UNEXPECTED_BLOCK_SIZE;
283
284	/* Check and see if this filesystem has already been added */
285	nr_users = ntohl(jsb->s_nr_users);
286	for (i=0; i < nr_users; i++) {
287		if (memcmp(fs->super->s_uuid,
288			   &jsb->s_users[i*16], 16) == 0)
289			break;
290	}
291	if (i >= nr_users) {
292		memcpy(&jsb->s_users[nr_users*16],
293		       fs->super->s_uuid, 16);
294		jsb->s_nr_users = htonl(nr_users+1);
295	}
296
297	/* Writeback the journal superblock */
298	if ((retval = io_channel_write_blk(journal_dev->io, start, -1024, buf)))
299		return retval;
300
301	fs->super->s_journal_inum = 0;
302	fs->super->s_journal_dev = st.st_rdev;
303	memcpy(fs->super->s_journal_uuid, jsb->s_uuid,
304	       sizeof(fs->super->s_journal_uuid));
305	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
306	ext2fs_mark_super_dirty(fs);
307	return 0;
308}
309
310/*
311 * This function adds a journal inode to a filesystem, using either
312 * POSIX routines if the filesystem is mounted, or using direct I/O
313 * functions if it is not.
314 */
315errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size, int flags)
316{
317	errcode_t		retval;
318	ext2_ino_t		journal_ino;
319	struct stat		st;
320	char			jfile[1024];
321	int			fd, mount_flags, f;
322
323	if ((retval = ext2fs_check_mount_point(fs->device_name, &mount_flags,
324					       jfile, sizeof(jfile)-10)))
325		return retval;
326
327	if (mount_flags & EXT2_MF_MOUNTED) {
328		strcat(jfile, "/.journal");
329
330		/*
331		 * If .../.journal already exists, make sure any
332		 * immutable or append-only flags are cleared.
333		 */
334#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
335		(void) chflags (jfile, 0);
336#else
337#if HAVE_EXT2_IOCTLS
338		fd = open(jfile, O_RDONLY);
339		if (fd >= 0) {
340			f = 0;
341			ioctl(fd, EXT2_IOC_SETFLAGS, &f);
342			close(fd);
343		}
344#endif
345#endif
346
347		/* Create the journal file */
348		if ((fd = open(jfile, O_CREAT|O_WRONLY, 0600)) < 0)
349			return errno;
350
351		if ((retval = write_journal_file(fs, jfile, size, flags)))
352			goto errout;
353
354		/* Get inode number of the journal file */
355		if (fstat(fd, &st) < 0)
356			goto errout;
357
358#if defined(HAVE_CHFLAGS) && defined(UF_NODUMP)
359		retval = fchflags (fd, UF_NODUMP|UF_IMMUTABLE);
360#else
361#if HAVE_EXT2_IOCTLS
362		f = EXT2_NODUMP_FL | EXT2_IMMUTABLE_FL;
363		retval = ioctl(fd, EXT2_IOC_SETFLAGS, &f);
364#endif
365#endif
366		if (retval)
367			goto errout;
368
369		close(fd);
370		journal_ino = st.st_ino;
371	} else {
372		journal_ino = EXT2_JOURNAL_INO;
373		if ((retval = write_journal_inode(fs, journal_ino,
374						  size, flags)))
375			return retval;
376	}
377
378	fs->super->s_journal_inum = journal_ino;
379	fs->super->s_journal_dev = 0;
380	memset(fs->super->s_journal_uuid, 0,
381	       sizeof(fs->super->s_journal_uuid));
382	fs->super->s_feature_compat |= EXT3_FEATURE_COMPAT_HAS_JOURNAL;
383
384	ext2fs_mark_super_dirty(fs);
385	return 0;
386errout:
387	close(fd);
388	return retval;
389}
390
391#ifdef DEBUG
392main(int argc, char **argv)
393{
394	errcode_t	retval;
395	char		*device_name;
396	ext2_filsys 	fs;
397
398	if (argc < 2) {
399		fprintf(stderr, "Usage: %s filesystem\n", argv[0]);
400		exit(1);
401	}
402	device_name = argv[1];
403
404	retval = ext2fs_open (device_name, EXT2_FLAG_RW, 0, 0,
405			      unix_io_manager, &fs);
406	if (retval) {
407		com_err(argv[0], retval, "while opening %s", device_name);
408		exit(1);
409	}
410
411	retval = ext2fs_add_journal_inode(fs, 1024);
412	if (retval) {
413		com_err(argv[0], retval, "while adding journal to %s",
414			device_name);
415		exit(1);
416	}
417	retval = ext2fs_flush(fs);
418	if (retval) {
419		printf("Warning, had trouble writing out superblocks.\n");
420	}
421	ext2fs_close(fs);
422	exit(0);
423
424}
425#endif
426