PageRenderTime 113ms CodeModel.GetById 57ms app.highlight 42ms RepoModel.GetById 1ms app.codeStats 0ms

/fs/omfs/inode.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 585 lines | 462 code | 91 blank | 32 comment | 64 complexity | e9b4bb786c94c92f3a0dcd62a689c888 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
  1/*
  2 * Optimized MPEG FS - inode and super operations.
  3 * Copyright (C) 2006 Bob Copeland <me@bobcopeland.com>
  4 * Released under GPL v2.
  5 */
  6#include <linux/module.h>
  7#include <linux/sched.h>
  8#include <linux/slab.h>
  9#include <linux/fs.h>
 10#include <linux/vfs.h>
 11#include <linux/parser.h>
 12#include <linux/buffer_head.h>
 13#include <linux/vmalloc.h>
 14#include <linux/writeback.h>
 15#include <linux/crc-itu-t.h>
 16#include "omfs.h"
 17
 18MODULE_AUTHOR("Bob Copeland <me@bobcopeland.com>");
 19MODULE_DESCRIPTION("OMFS (ReplayTV/Karma) Filesystem for Linux");
 20MODULE_LICENSE("GPL");
 21
 22struct buffer_head *omfs_bread(struct super_block *sb, sector_t block)
 23{
 24	struct omfs_sb_info *sbi = OMFS_SB(sb);
 25	if (block >= sbi->s_num_blocks)
 26		return NULL;
 27
 28	return sb_bread(sb, clus_to_blk(sbi, block));
 29}
 30
 31struct inode *omfs_new_inode(struct inode *dir, int mode)
 32{
 33	struct inode *inode;
 34	u64 new_block;
 35	int err;
 36	int len;
 37	struct omfs_sb_info *sbi = OMFS_SB(dir->i_sb);
 38
 39	inode = new_inode(dir->i_sb);
 40	if (!inode)
 41		return ERR_PTR(-ENOMEM);
 42
 43	err = omfs_allocate_range(dir->i_sb, sbi->s_mirrors, sbi->s_mirrors,
 44			&new_block, &len);
 45	if (err)
 46		goto fail;
 47
 48	inode->i_ino = new_block;
 49	inode_init_owner(inode, NULL, mode);
 50	inode->i_mapping->a_ops = &omfs_aops;
 51
 52	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 53	switch (mode & S_IFMT) {
 54	case S_IFDIR:
 55		inode->i_op = &omfs_dir_inops;
 56		inode->i_fop = &omfs_dir_operations;
 57		inode->i_size = sbi->s_sys_blocksize;
 58		inc_nlink(inode);
 59		break;
 60	case S_IFREG:
 61		inode->i_op = &omfs_file_inops;
 62		inode->i_fop = &omfs_file_operations;
 63		inode->i_size = 0;
 64		break;
 65	}
 66
 67	insert_inode_hash(inode);
 68	mark_inode_dirty(inode);
 69	return inode;
 70fail:
 71	make_bad_inode(inode);
 72	iput(inode);
 73	return ERR_PTR(err);
 74}
 75
 76/*
 77 * Update the header checksums for a dirty inode based on its contents.
 78 * Caller is expected to hold the buffer head underlying oi and mark it
 79 * dirty.
 80 */
 81static void omfs_update_checksums(struct omfs_inode *oi)
 82{
 83	int xor, i, ofs = 0, count;
 84	u16 crc = 0;
 85	unsigned char *ptr = (unsigned char *) oi;
 86
 87	count = be32_to_cpu(oi->i_head.h_body_size);
 88	ofs = sizeof(struct omfs_header);
 89
 90	crc = crc_itu_t(crc, ptr + ofs, count);
 91	oi->i_head.h_crc = cpu_to_be16(crc);
 92
 93	xor = ptr[0];
 94	for (i = 1; i < OMFS_XOR_COUNT; i++)
 95		xor ^= ptr[i];
 96
 97	oi->i_head.h_check_xor = xor;
 98}
 99
100static int __omfs_write_inode(struct inode *inode, int wait)
101{
102	struct omfs_inode *oi;
103	struct omfs_sb_info *sbi = OMFS_SB(inode->i_sb);
104	struct buffer_head *bh, *bh2;
105	u64 ctime;
106	int i;
107	int ret = -EIO;
108	int sync_failed = 0;
109
110	/* get current inode since we may have written sibling ptrs etc. */
111	bh = omfs_bread(inode->i_sb, inode->i_ino);
112	if (!bh)
113		goto out;
114
115	oi = (struct omfs_inode *) bh->b_data;
116
117	oi->i_head.h_self = cpu_to_be64(inode->i_ino);
118	if (S_ISDIR(inode->i_mode))
119		oi->i_type = OMFS_DIR;
120	else if (S_ISREG(inode->i_mode))
121		oi->i_type = OMFS_FILE;
122	else {
123		printk(KERN_WARNING "omfs: unknown file type: %d\n",
124			inode->i_mode);
125		goto out_brelse;
126	}
127
128	oi->i_head.h_body_size = cpu_to_be32(sbi->s_sys_blocksize -
129		sizeof(struct omfs_header));
130	oi->i_head.h_version = 1;
131	oi->i_head.h_type = OMFS_INODE_NORMAL;
132	oi->i_head.h_magic = OMFS_IMAGIC;
133	oi->i_size = cpu_to_be64(inode->i_size);
134
135	ctime = inode->i_ctime.tv_sec * 1000LL +
136		((inode->i_ctime.tv_nsec + 999)/1000);
137	oi->i_ctime = cpu_to_be64(ctime);
138
139	omfs_update_checksums(oi);
140
141	mark_buffer_dirty(bh);
142	if (wait) {
143		sync_dirty_buffer(bh);
144		if (buffer_req(bh) && !buffer_uptodate(bh))
145			sync_failed = 1;
146	}
147
148	/* if mirroring writes, copy to next fsblock */
149	for (i = 1; i < sbi->s_mirrors; i++) {
150		bh2 = omfs_bread(inode->i_sb, inode->i_ino + i);
151		if (!bh2)
152			goto out_brelse;
153
154		memcpy(bh2->b_data, bh->b_data, bh->b_size);
155		mark_buffer_dirty(bh2);
156		if (wait) {
157			sync_dirty_buffer(bh2);
158			if (buffer_req(bh2) && !buffer_uptodate(bh2))
159				sync_failed = 1;
160		}
161		brelse(bh2);
162	}
163	ret = (sync_failed) ? -EIO : 0;
164out_brelse:
165	brelse(bh);
166out:
167	return ret;
168}
169
170static int omfs_write_inode(struct inode *inode, struct writeback_control *wbc)
171{
172	return __omfs_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
173}
174
175int omfs_sync_inode(struct inode *inode)
176{
177	return __omfs_write_inode(inode, 1);
178}
179
180/*
181 * called when an entry is deleted, need to clear the bits in the
182 * bitmaps.
183 */
184static void omfs_evict_inode(struct inode *inode)
185{
186	truncate_inode_pages(&inode->i_data, 0);
187	end_writeback(inode);
188
189	if (inode->i_nlink)
190		return;
191
192	if (S_ISREG(inode->i_mode)) {
193		inode->i_size = 0;
194		omfs_shrink_inode(inode);
195	}
196
197	omfs_clear_range(inode->i_sb, inode->i_ino, 2);
198}
199
200struct inode *omfs_iget(struct super_block *sb, ino_t ino)
201{
202	struct omfs_sb_info *sbi = OMFS_SB(sb);
203	struct omfs_inode *oi;
204	struct buffer_head *bh;
205	u64 ctime;
206	unsigned long nsecs;
207	struct inode *inode;
208
209	inode = iget_locked(sb, ino);
210	if (!inode)
211		return ERR_PTR(-ENOMEM);
212	if (!(inode->i_state & I_NEW))
213		return inode;
214
215	bh = omfs_bread(inode->i_sb, ino);
216	if (!bh)
217		goto iget_failed;
218
219	oi = (struct omfs_inode *)bh->b_data;
220
221	/* check self */
222	if (ino != be64_to_cpu(oi->i_head.h_self))
223		goto fail_bh;
224
225	inode->i_uid = sbi->s_uid;
226	inode->i_gid = sbi->s_gid;
227
228	ctime = be64_to_cpu(oi->i_ctime);
229	nsecs = do_div(ctime, 1000) * 1000L;
230
231	inode->i_atime.tv_sec = ctime;
232	inode->i_mtime.tv_sec = ctime;
233	inode->i_ctime.tv_sec = ctime;
234	inode->i_atime.tv_nsec = nsecs;
235	inode->i_mtime.tv_nsec = nsecs;
236	inode->i_ctime.tv_nsec = nsecs;
237
238	inode->i_mapping->a_ops = &omfs_aops;
239
240	switch (oi->i_type) {
241	case OMFS_DIR:
242		inode->i_mode = S_IFDIR | (S_IRWXUGO & ~sbi->s_dmask);
243		inode->i_op = &omfs_dir_inops;
244		inode->i_fop = &omfs_dir_operations;
245		inode->i_size = sbi->s_sys_blocksize;
246		inc_nlink(inode);
247		break;
248	case OMFS_FILE:
249		inode->i_mode = S_IFREG | (S_IRWXUGO & ~sbi->s_fmask);
250		inode->i_fop = &omfs_file_operations;
251		inode->i_size = be64_to_cpu(oi->i_size);
252		break;
253	}
254	brelse(bh);
255	unlock_new_inode(inode);
256	return inode;
257fail_bh:
258	brelse(bh);
259iget_failed:
260	iget_failed(inode);
261	return ERR_PTR(-EIO);
262}
263
264static void omfs_put_super(struct super_block *sb)
265{
266	struct omfs_sb_info *sbi = OMFS_SB(sb);
267	kfree(sbi->s_imap);
268	kfree(sbi);
269	sb->s_fs_info = NULL;
270}
271
272static int omfs_statfs(struct dentry *dentry, struct kstatfs *buf)
273{
274	struct super_block *s = dentry->d_sb;
275	struct omfs_sb_info *sbi = OMFS_SB(s);
276	u64 id = huge_encode_dev(s->s_bdev->bd_dev);
277
278	buf->f_type = OMFS_MAGIC;
279	buf->f_bsize = sbi->s_blocksize;
280	buf->f_blocks = sbi->s_num_blocks;
281	buf->f_files = sbi->s_num_blocks;
282	buf->f_namelen = OMFS_NAMELEN;
283	buf->f_fsid.val[0] = (u32)id;
284	buf->f_fsid.val[1] = (u32)(id >> 32);
285
286	buf->f_bfree = buf->f_bavail = buf->f_ffree =
287		omfs_count_free(s);
288
289	return 0;
290}
291
292static const struct super_operations omfs_sops = {
293	.write_inode	= omfs_write_inode,
294	.evict_inode	= omfs_evict_inode,
295	.put_super	= omfs_put_super,
296	.statfs		= omfs_statfs,
297	.show_options	= generic_show_options,
298};
299
300/*
301 * For Rio Karma, there is an on-disk free bitmap whose location is
302 * stored in the root block.  For ReplayTV, there is no such free bitmap
303 * so we have to walk the tree.  Both inodes and file data are allocated
304 * from the same map.  This array can be big (300k) so we allocate
305 * in units of the blocksize.
306 */
307static int omfs_get_imap(struct super_block *sb)
308{
309	int bitmap_size;
310	int array_size;
311	int count;
312	struct omfs_sb_info *sbi = OMFS_SB(sb);
313	struct buffer_head *bh;
314	unsigned long **ptr;
315	sector_t block;
316
317	bitmap_size = DIV_ROUND_UP(sbi->s_num_blocks, 8);
318	array_size = DIV_ROUND_UP(bitmap_size, sb->s_blocksize);
319
320	if (sbi->s_bitmap_ino == ~0ULL)
321		goto out;
322
323	sbi->s_imap_size = array_size;
324	sbi->s_imap = kzalloc(array_size * sizeof(unsigned long *), GFP_KERNEL);
325	if (!sbi->s_imap)
326		goto nomem;
327
328	block = clus_to_blk(sbi, sbi->s_bitmap_ino);
329	if (block >= sbi->s_num_blocks)
330		goto nomem;
331
332	ptr = sbi->s_imap;
333	for (count = bitmap_size; count > 0; count -= sb->s_blocksize) {
334		bh = sb_bread(sb, block++);
335		if (!bh)
336			goto nomem_free;
337		*ptr = kmalloc(sb->s_blocksize, GFP_KERNEL);
338		if (!*ptr) {
339			brelse(bh);
340			goto nomem_free;
341		}
342		memcpy(*ptr, bh->b_data, sb->s_blocksize);
343		if (count < sb->s_blocksize)
344			memset((void *)*ptr + count, 0xff,
345				sb->s_blocksize - count);
346		brelse(bh);
347		ptr++;
348	}
349out:
350	return 0;
351
352nomem_free:
353	for (count = 0; count < array_size; count++)
354		kfree(sbi->s_imap[count]);
355
356	kfree(sbi->s_imap);
357nomem:
358	sbi->s_imap = NULL;
359	sbi->s_imap_size = 0;
360	return -ENOMEM;
361}
362
363enum {
364	Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask
365};
366
367static const match_table_t tokens = {
368	{Opt_uid, "uid=%u"},
369	{Opt_gid, "gid=%u"},
370	{Opt_umask, "umask=%o"},
371	{Opt_dmask, "dmask=%o"},
372	{Opt_fmask, "fmask=%o"},
373};
374
375static int parse_options(char *options, struct omfs_sb_info *sbi)
376{
377	char *p;
378	substring_t args[MAX_OPT_ARGS];
379	int option;
380
381	if (!options)
382		return 1;
383
384	while ((p = strsep(&options, ",")) != NULL) {
385		int token;
386		if (!*p)
387			continue;
388
389		token = match_token(p, tokens, args);
390		switch (token) {
391		case Opt_uid:
392			if (match_int(&args[0], &option))
393				return 0;
394			sbi->s_uid = option;
395			break;
396		case Opt_gid:
397			if (match_int(&args[0], &option))
398				return 0;
399			sbi->s_gid = option;
400			break;
401		case Opt_umask:
402			if (match_octal(&args[0], &option))
403				return 0;
404			sbi->s_fmask = sbi->s_dmask = option;
405			break;
406		case Opt_dmask:
407			if (match_octal(&args[0], &option))
408				return 0;
409			sbi->s_dmask = option;
410			break;
411		case Opt_fmask:
412			if (match_octal(&args[0], &option))
413				return 0;
414			sbi->s_fmask = option;
415			break;
416		default:
417			return 0;
418		}
419	}
420	return 1;
421}
422
423static int omfs_fill_super(struct super_block *sb, void *data, int silent)
424{
425	struct buffer_head *bh, *bh2;
426	struct omfs_super_block *omfs_sb;
427	struct omfs_root_block *omfs_rb;
428	struct omfs_sb_info *sbi;
429	struct inode *root;
430	int ret = -EINVAL;
431
432	save_mount_options(sb, (char *) data);
433
434	sbi = kzalloc(sizeof(struct omfs_sb_info), GFP_KERNEL);
435	if (!sbi)
436		return -ENOMEM;
437
438	sb->s_fs_info = sbi;
439
440	sbi->s_uid = current_uid();
441	sbi->s_gid = current_gid();
442	sbi->s_dmask = sbi->s_fmask = current_umask();
443
444	if (!parse_options((char *) data, sbi))
445		goto end;
446
447	sb->s_maxbytes = 0xffffffff;
448
449	sb_set_blocksize(sb, 0x200);
450
451	bh = sb_bread(sb, 0);
452	if (!bh)
453		goto end;
454
455	omfs_sb = (struct omfs_super_block *)bh->b_data;
456
457	if (omfs_sb->s_magic != cpu_to_be32(OMFS_MAGIC)) {
458		if (!silent)
459			printk(KERN_ERR "omfs: Invalid superblock (%x)\n",
460				   omfs_sb->s_magic);
461		goto out_brelse_bh;
462	}
463	sb->s_magic = OMFS_MAGIC;
464
465	sbi->s_num_blocks = be64_to_cpu(omfs_sb->s_num_blocks);
466	sbi->s_blocksize = be32_to_cpu(omfs_sb->s_blocksize);
467	sbi->s_mirrors = be32_to_cpu(omfs_sb->s_mirrors);
468	sbi->s_root_ino = be64_to_cpu(omfs_sb->s_root_block);
469	sbi->s_sys_blocksize = be32_to_cpu(omfs_sb->s_sys_blocksize);
470	mutex_init(&sbi->s_bitmap_lock);
471
472	if (sbi->s_sys_blocksize > PAGE_SIZE) {
473		printk(KERN_ERR "omfs: sysblock size (%d) is out of range\n",
474			sbi->s_sys_blocksize);
475		goto out_brelse_bh;
476	}
477
478	if (sbi->s_blocksize < sbi->s_sys_blocksize ||
479	    sbi->s_blocksize > OMFS_MAX_BLOCK_SIZE) {
480		printk(KERN_ERR "omfs: block size (%d) is out of range\n",
481			sbi->s_blocksize);
482		goto out_brelse_bh;
483	}
484
485	/*
486	 * Use sys_blocksize as the fs block since it is smaller than a
487	 * page while the fs blocksize can be larger.
488	 */
489	sb_set_blocksize(sb, sbi->s_sys_blocksize);
490
491	/*
492	 * ...and the difference goes into a shift.  sys_blocksize is always
493	 * a power of two factor of blocksize.
494	 */
495	sbi->s_block_shift = get_bitmask_order(sbi->s_blocksize) -
496		get_bitmask_order(sbi->s_sys_blocksize);
497
498	bh2 = omfs_bread(sb, be64_to_cpu(omfs_sb->s_root_block));
499	if (!bh2)
500		goto out_brelse_bh;
501
502	omfs_rb = (struct omfs_root_block *)bh2->b_data;
503
504	sbi->s_bitmap_ino = be64_to_cpu(omfs_rb->r_bitmap);
505	sbi->s_clustersize = be32_to_cpu(omfs_rb->r_clustersize);
506
507	if (sbi->s_num_blocks != be64_to_cpu(omfs_rb->r_num_blocks)) {
508		printk(KERN_ERR "omfs: block count discrepancy between "
509			"super and root blocks (%llx, %llx)\n",
510			(unsigned long long)sbi->s_num_blocks,
511			(unsigned long long)be64_to_cpu(omfs_rb->r_num_blocks));
512		goto out_brelse_bh2;
513	}
514
515	if (sbi->s_bitmap_ino != ~0ULL &&
516	    sbi->s_bitmap_ino > sbi->s_num_blocks) {
517		printk(KERN_ERR "omfs: free space bitmap location is corrupt "
518			"(%llx, total blocks %llx)\n",
519			(unsigned long long) sbi->s_bitmap_ino,
520			(unsigned long long) sbi->s_num_blocks);
521		goto out_brelse_bh2;
522	}
523	if (sbi->s_clustersize < 1 ||
524	    sbi->s_clustersize > OMFS_MAX_CLUSTER_SIZE) {
525		printk(KERN_ERR "omfs: cluster size out of range (%d)",
526			sbi->s_clustersize);
527		goto out_brelse_bh2;
528	}
529
530	ret = omfs_get_imap(sb);
531	if (ret)
532		goto out_brelse_bh2;
533
534	sb->s_op = &omfs_sops;
535
536	root = omfs_iget(sb, be64_to_cpu(omfs_rb->r_root_dir));
537	if (IS_ERR(root)) {
538		ret = PTR_ERR(root);
539		goto out_brelse_bh2;
540	}
541
542	sb->s_root = d_alloc_root(root);
543	if (!sb->s_root) {
544		iput(root);
545		goto out_brelse_bh2;
546	}
547	printk(KERN_DEBUG "omfs: Mounted volume %s\n", omfs_rb->r_name);
548
549	ret = 0;
550out_brelse_bh2:
551	brelse(bh2);
552out_brelse_bh:
553	brelse(bh);
554end:
555	if (ret)
556		kfree(sbi);
557	return ret;
558}
559
560static struct dentry *omfs_mount(struct file_system_type *fs_type,
561			int flags, const char *dev_name, void *data)
562{
563	return mount_bdev(fs_type, flags, dev_name, data, omfs_fill_super);
564}
565
566static struct file_system_type omfs_fs_type = {
567	.owner = THIS_MODULE,
568	.name = "omfs",
569	.mount = omfs_mount,
570	.kill_sb = kill_block_super,
571	.fs_flags = FS_REQUIRES_DEV,
572};
573
574static int __init init_omfs_fs(void)
575{
576	return register_filesystem(&omfs_fs_type);
577}
578
579static void __exit exit_omfs_fs(void)
580{
581	unregister_filesystem(&omfs_fs_type);
582}
583
584module_init(init_omfs_fs);
585module_exit(exit_omfs_fs);