aboutsummaryrefslogtreecommitdiff
path: root/fs/vboxsf/dir.c
blob: dd147b490982c198f034dce9d3d87f5599a13f83 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
// SPDX-License-Identifier: MIT
/*
 * VirtualBox Guest Shared Folders support: Directory inode and file operations
 *
 * Copyright (C) 2006-2018 Oracle Corporation
 */

#include <linux/namei.h>
#include <linux/vbox_utils.h>
#include "vfsmod.h"

static int vboxsf_dir_open(struct inode *inode, struct file *file)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(inode->i_sb);
	struct shfl_createparms params = {};
	struct vboxsf_dir_info *sf_d;
	int err;

	sf_d = vboxsf_dir_info_alloc();
	if (!sf_d)
		return -ENOMEM;

	params.handle = SHFL_HANDLE_NIL;
	params.create_flags = SHFL_CF_DIRECTORY | SHFL_CF_ACT_OPEN_IF_EXISTS |
			      SHFL_CF_ACT_FAIL_IF_NEW | SHFL_CF_ACCESS_READ;

	err = vboxsf_create_at_dentry(file_dentry(file), &params);
	if (err)
		goto err_free_dir_info;

	if (params.result != SHFL_FILE_EXISTS) {
		err = -ENOENT;
		goto err_close;
	}

	err = vboxsf_dir_read_all(sbi, sf_d, params.handle);
	if (err)
		goto err_close;

	vboxsf_close(sbi->root, params.handle);
	file->private_data = sf_d;
	return 0;

err_close:
	vboxsf_close(sbi->root, params.handle);
err_free_dir_info:
	vboxsf_dir_info_free(sf_d);
	return err;
}

static int vboxsf_dir_release(struct inode *inode, struct file *file)
{
	if (file->private_data)
		vboxsf_dir_info_free(file->private_data);

	return 0;
}

static unsigned int vboxsf_get_d_type(u32 mode)
{
	unsigned int d_type;

	switch (mode & SHFL_TYPE_MASK) {
	case SHFL_TYPE_FIFO:
		d_type = DT_FIFO;
		break;
	case SHFL_TYPE_DEV_CHAR:
		d_type = DT_CHR;
		break;
	case SHFL_TYPE_DIRECTORY:
		d_type = DT_DIR;
		break;
	case SHFL_TYPE_DEV_BLOCK:
		d_type = DT_BLK;
		break;
	case SHFL_TYPE_FILE:
		d_type = DT_REG;
		break;
	case SHFL_TYPE_SYMLINK:
		d_type = DT_LNK;
		break;
	case SHFL_TYPE_SOCKET:
		d_type = DT_SOCK;
		break;
	case SHFL_TYPE_WHITEOUT:
		d_type = DT_WHT;
		break;
	default:
		d_type = DT_UNKNOWN;
		break;
	}
	return d_type;
}

static bool vboxsf_dir_emit(struct file *dir, struct dir_context *ctx)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(file_inode(dir)->i_sb);
	struct vboxsf_dir_info *sf_d = dir->private_data;
	struct shfl_dirinfo *info;
	struct vboxsf_dir_buf *b;
	unsigned int d_type;
	loff_t i, cur = 0;
	ino_t fake_ino;
	void *end;
	int err;

	list_for_each_entry(b, &sf_d->info_list, head) {
try_next_entry:
		if (ctx->pos >= cur + b->entries) {
			cur += b->entries;
			continue;
		}

		/*
		 * Note the vboxsf_dir_info objects we are iterating over here
		 * are variable sized, so the info pointer may end up being
		 * unaligned. This is how we get the data from the host.
		 * Since vboxsf is only supported on x86 machines this is not
		 * a problem.
		 */
		for (i = 0, info = b->buf; i < ctx->pos - cur; i++) {
			end = &info->name.string.utf8[info->name.size];
			/* Only happens if the host gives us corrupt data */
			if (WARN_ON(end > (b->buf + b->used)))
				return false;
			info = end;
		}

		end = &info->name.string.utf8[info->name.size];
		if (WARN_ON(end > (b->buf + b->used)))
			return false;

		/* Info now points to the right entry, emit it. */
		d_type = vboxsf_get_d_type(info->info.attr.mode);

		/*
		 * On 32 bit systems pos is 64 signed, while ino is 32 bit
		 * unsigned so fake_ino may overflow, check for this.
		 */
		if ((ino_t)(ctx->pos + 1) != (u64)(ctx->pos + 1)) {
			vbg_err("vboxsf: fake ino overflow, truncating dir\n");
			return false;
		}
		fake_ino = ctx->pos + 1;

		if (sbi->nls) {
			char d_name[NAME_MAX];

			err = vboxsf_nlscpy(sbi, d_name, NAME_MAX,
					    info->name.string.utf8,
					    info->name.length);
			if (err) {
				/* skip erroneous entry and proceed */
				ctx->pos += 1;
				goto try_next_entry;
			}

			return dir_emit(ctx, d_name, strlen(d_name),
					fake_ino, d_type);
		}

		return dir_emit(ctx, info->name.string.utf8, info->name.length,
				fake_ino, d_type);
	}

	return false;
}

static int vboxsf_dir_iterate(struct file *dir, struct dir_context *ctx)
{
	bool emitted;

	do {
		emitted = vboxsf_dir_emit(dir, ctx);
		if (emitted)
			ctx->pos += 1;
	} while (emitted);

	return 0;
}

const struct file_operations vboxsf_dir_fops = {
	.open = vboxsf_dir_open,
	.iterate = vboxsf_dir_iterate,
	.release = vboxsf_dir_release,
	.read = generic_read_dir,
	.llseek = generic_file_llseek,
};

/*
 * This is called during name resolution/lookup to check if the @dentry in
 * the cache is still valid. the job is handled by vboxsf_inode_revalidate.
 */
static int vboxsf_dentry_revalidate(struct dentry *dentry, unsigned int flags)
{
	if (flags & LOOKUP_RCU)
		return -ECHILD;

	if (d_really_is_positive(dentry))
		return vboxsf_inode_revalidate(dentry) == 0;
	else
		return vboxsf_stat_dentry(dentry, NULL) == -ENOENT;
}

const struct dentry_operations vboxsf_dentry_ops = {
	.d_revalidate = vboxsf_dentry_revalidate
};

/* iops */

static struct dentry *vboxsf_dir_lookup(struct inode *parent,
					struct dentry *dentry,
					unsigned int flags)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
	struct shfl_fsobjinfo fsinfo;
	struct inode *inode;
	int err;

	dentry->d_time = jiffies;

	err = vboxsf_stat_dentry(dentry, &fsinfo);
	if (err) {
		inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
	} else {
		inode = vboxsf_new_inode(parent->i_sb);
		if (!IS_ERR(inode))
			vboxsf_init_inode(sbi, inode, &fsinfo);
	}

	return d_splice_alias(inode, dentry);
}

static int vboxsf_dir_instantiate(struct inode *parent, struct dentry *dentry,
				  struct shfl_fsobjinfo *info)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
	struct vboxsf_inode *sf_i;
	struct inode *inode;

	inode = vboxsf_new_inode(parent->i_sb);
	if (IS_ERR(inode))
		return PTR_ERR(inode);

	sf_i = VBOXSF_I(inode);
	/* The host may have given us different attr then requested */
	sf_i->force_restat = 1;
	vboxsf_init_inode(sbi, inode, info);

	d_instantiate(dentry, inode);

	return 0;
}

static int vboxsf_dir_create(struct inode *parent, struct dentry *dentry,
			     umode_t mode, int is_dir)
{
	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
	struct shfl_createparms params = {};
	int err;

	params.handle = SHFL_HANDLE_NIL;
	params.create_flags = SHFL_CF_ACT_CREATE_IF_NEW |
			      SHFL_CF_ACT_FAIL_IF_EXISTS |
			      SHFL_CF_ACCESS_READWRITE |
			      (is_dir ? SHFL_CF_DIRECTORY : 0);
	params.info.attr.mode = (mode & 0777) |
				(is_dir ? SHFL_TYPE_DIRECTORY : SHFL_TYPE_FILE);
	params.info.attr.additional = SHFLFSOBJATTRADD_NOTHING;

	err = vboxsf_create_at_dentry(dentry, &params);
	if (err)
		return err;

	if (params.result != SHFL_FILE_CREATED)
		return -EPERM;

	vboxsf_close(sbi->root, params.handle);

	err = vboxsf_dir_instantiate(parent, dentry, &params.info);
	if (err)
		return err;

	/* parent directory access/change time changed */
	sf_parent_i->force_restat = 1;

	return 0;
}

static int vboxsf_dir_mkfile(struct inode *parent, struct dentry *dentry,
			     umode_t mode, bool excl)
{
	return vboxsf_dir_create(parent, dentry, mode, 0);
}

static int vboxsf_dir_mkdir(struct inode *parent, struct dentry *dentry,
			    umode_t mode)
{
	return vboxsf_dir_create(parent, dentry, mode, 1);
}

static int vboxsf_dir_unlink(struct inode *parent, struct dentry *dentry)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
	struct inode *inode = d_inode(dentry);
	struct shfl_string *path;
	u32 flags;
	int err;

	if (S_ISDIR(inode->i_mode))
		flags = SHFL_REMOVE_DIR;
	else
		flags = SHFL_REMOVE_FILE;

	if (S_ISLNK(inode->i_mode))
		flags |= SHFL_REMOVE_SYMLINK;

	path = vboxsf_path_from_dentry(sbi, dentry);
	if (IS_ERR(path))
		return PTR_ERR(path);

	err = vboxsf_remove(sbi->root, path, flags);
	__putname(path);
	if (err)
		return err;

	/* parent directory access/change time changed */
	sf_parent_i->force_restat = 1;

	return 0;
}

static int vboxsf_dir_rename(struct inode *old_parent,
			     struct dentry *old_dentry,
			     struct inode *new_parent,
			     struct dentry *new_dentry,
			     unsigned int flags)
{
	struct vboxsf_sbi *sbi = VBOXSF_SBI(old_parent->i_sb);
	struct vboxsf_inode *sf_old_parent_i = VBOXSF_I(old_parent);
	struct vboxsf_inode *sf_new_parent_i = VBOXSF_I(new_parent);
	u32 shfl_flags = SHFL_RENAME_FILE | SHFL_RENAME_REPLACE_IF_EXISTS;
	struct shfl_string *old_path, *new_path;
	int err;

	if (flags)
		return -EINVAL;

	old_path = vboxsf_path_from_dentry(sbi, old_dentry);
	if (IS_ERR(old_path))
		return PTR_ERR(old_path);

	new_path = vboxsf_path_from_dentry(sbi, new_dentry);
	if (IS_ERR(new_path)) {
		err = PTR_ERR(new_path);
		goto err_put_old_path;
	}

	if (d_inode(old_dentry)->i_mode & S_IFDIR)
		shfl_flags = 0;

	err = vboxsf_rename(sbi->root, old_path, new_path, shfl_flags);
	if (err == 0) {
		/* parent directories access/change time changed */
		sf_new_parent_i->force_restat = 1;
		sf_old_parent_i->force_restat = 1;
	}

	__putname(new_path);
err_put_old_path:
	__putname(old_path);
	return err;
}

static int vboxsf_dir_symlink(struct inode *parent, struct dentry *dentry,
			      const char *symname)
{
	struct vboxsf_inode *sf_parent_i = VBOXSF_I(parent);
	struct vboxsf_sbi *sbi = VBOXSF_SBI(parent->i_sb);
	int symname_size = strlen(symname) + 1;
	struct shfl_string *path, *ssymname;
	struct shfl_fsobjinfo info;
	int err;

	path = vboxsf_path_from_dentry(sbi, dentry);
	if (IS_ERR(path))
		return PTR_ERR(path);

	ssymname = kmalloc(SHFLSTRING_HEADER_SIZE + symname_size, GFP_KERNEL);
	if (!ssymname) {
		__putname(path);
		return -ENOMEM;
	}
	ssymname->length = symname_size - 1;
	ssymname->size = symname_size;
	memcpy(ssymname->string.utf8, symname, symname_size);

	err = vboxsf_symlink(sbi->root, path, ssymname, &info);
	kfree(ssymname);
	__putname(path);
	if (err) {
		/* -EROFS means symlinks are note support -> -EPERM */
		return (err == -EROFS) ? -EPERM : err;
	}

	err = vboxsf_dir_instantiate(parent, dentry, &info);
	if (err)
		return err;

	/* parent directory access/change time changed */
	sf_parent_i->force_restat = 1;
	return 0;
}

const struct inode_operations vboxsf_dir_iops = {
	.lookup  = vboxsf_dir_lookup,
	.create  = vboxsf_dir_mkfile,
	.mkdir   = vboxsf_dir_mkdir,
	.rmdir   = vboxsf_dir_unlink,
	.unlink  = vboxsf_dir_unlink,
	.rename  = vboxsf_dir_rename,
	.symlink = vboxsf_dir_symlink,
	.getattr = vboxsf_getattr,
	.setattr = vboxsf_setattr,
};