aboutsummaryrefslogtreecommitdiffstats
path: root/module/spl/spl-vnode.c
blob: 1e26b8e29a89e736f82e26a2a87e5606326bc889 (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
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
/*****************************************************************************\
 *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
 *  Copyright (C) 2007 The Regents of the University of California.
 *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
 *  UCRL-CODE-235197
 *
 *  This file is part of the SPL, Solaris Porting Layer.
 *  For details, see <http://zfsonlinux.org/>.
 *
 *  The SPL is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  The SPL is distributed in the hope that it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
 *****************************************************************************
 *  Solaris Porting Layer (SPL) Vnode Implementation.
\*****************************************************************************/

#include <sys/cred.h>
#include <sys/vnode.h>
#include <sys/kmem_cache.h>
#include <linux/falloc.h>
#include <linux/file_compat.h>

vnode_t *rootdir = (vnode_t *)0xabcd1234;
EXPORT_SYMBOL(rootdir);

static spl_kmem_cache_t *vn_cache;
static spl_kmem_cache_t *vn_file_cache;

static DEFINE_SPINLOCK(vn_file_lock);
static LIST_HEAD(vn_file_list);

vtype_t
vn_mode_to_vtype(mode_t mode)
{
	if (S_ISREG(mode))
		return VREG;

	if (S_ISDIR(mode))
		return VDIR;

	if (S_ISCHR(mode))
		return VCHR;

	if (S_ISBLK(mode))
		return VBLK;

	if (S_ISFIFO(mode))
		return VFIFO;

	if (S_ISLNK(mode))
		return VLNK;

	if (S_ISSOCK(mode))
		return VSOCK;

	if (S_ISCHR(mode))
		return VCHR;

	return VNON;
} /* vn_mode_to_vtype() */
EXPORT_SYMBOL(vn_mode_to_vtype);

mode_t
vn_vtype_to_mode(vtype_t vtype)
{
	if (vtype == VREG)
		return S_IFREG;

	if (vtype == VDIR)
		return S_IFDIR;

	if (vtype == VCHR)
		return S_IFCHR;

	if (vtype == VBLK)
		return S_IFBLK;

	if (vtype == VFIFO)
		return S_IFIFO;

	if (vtype == VLNK)
		return S_IFLNK;

	if (vtype == VSOCK)
		return S_IFSOCK;

	return VNON;
} /* vn_vtype_to_mode() */
EXPORT_SYMBOL(vn_vtype_to_mode);

vnode_t *
vn_alloc(int flag)
{
	vnode_t *vp;

	vp = kmem_cache_alloc(vn_cache, flag);
	if (vp != NULL) {
		vp->v_file = NULL;
		vp->v_type = 0;
	}

	return (vp);
} /* vn_alloc() */
EXPORT_SYMBOL(vn_alloc);

void
vn_free(vnode_t *vp)
{
	kmem_cache_free(vn_cache, vp);
} /* vn_free() */
EXPORT_SYMBOL(vn_free);

int
vn_open(const char *path, uio_seg_t seg, int flags, int mode,
	vnode_t **vpp, int x1, void *x2)
{
	struct file *fp;
	struct kstat stat;
	int rc, saved_umask = 0;
	gfp_t saved_gfp;
	vnode_t *vp;

	ASSERT(flags & (FWRITE | FREAD));
	ASSERT(seg == UIO_SYSSPACE);
	ASSERT(vpp);
	*vpp = NULL;

	if (!(flags & FCREAT) && (flags & FWRITE))
		flags |= FEXCL;

	/* Note for filp_open() the two low bits must be remapped to mean:
	 * 01 - read-only  -> 00 read-only
	 * 10 - write-only -> 01 write-only
	 * 11 - read-write -> 10 read-write
	 */
	flags--;

	if (flags & FCREAT)
		saved_umask = xchg(&current->fs->umask, 0);

	fp = filp_open(path, flags, mode);

	if (flags & FCREAT)
		(void)xchg(&current->fs->umask, saved_umask);

	if (IS_ERR(fp))
		return (-PTR_ERR(fp));

#ifdef HAVE_2ARGS_VFS_GETATTR
	rc = vfs_getattr(&fp->f_path, &stat);
#else
	rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
#endif
	if (rc) {
		filp_close(fp, 0);
		return (-rc);
	}

	vp = vn_alloc(KM_SLEEP);
	if (!vp) {
		filp_close(fp, 0);
		return (ENOMEM);
	}

	saved_gfp = mapping_gfp_mask(fp->f_mapping);
	mapping_set_gfp_mask(fp->f_mapping, saved_gfp & ~(__GFP_IO|__GFP_FS));

	mutex_enter(&vp->v_lock);
	vp->v_type = vn_mode_to_vtype(stat.mode);
	vp->v_file = fp;
	vp->v_gfp_mask = saved_gfp;
	*vpp = vp;
	mutex_exit(&vp->v_lock);

	return (0);
} /* vn_open() */
EXPORT_SYMBOL(vn_open);

int
vn_openat(const char *path, uio_seg_t seg, int flags, int mode,
	  vnode_t **vpp, int x1, void *x2, vnode_t *vp, int fd)
{
	char *realpath;
	int len, rc;

	ASSERT(vp == rootdir);

	len = strlen(path) + 2;
	realpath = kmalloc(len, kmem_flags_convert(KM_SLEEP));
	if (!realpath)
		return (ENOMEM);

	(void)snprintf(realpath, len, "/%s", path);
	rc = vn_open(realpath, seg, flags, mode, vpp, x1, x2);
	kfree(realpath);

	return (rc);
} /* vn_openat() */
EXPORT_SYMBOL(vn_openat);

int
vn_rdwr(uio_rw_t uio, vnode_t *vp, void *addr, ssize_t len, offset_t off,
	uio_seg_t seg, int ioflag, rlim64_t x2, void *x3, ssize_t *residp)
{
	loff_t offset;
	mm_segment_t saved_fs;
	struct file *fp;
	int rc;

	ASSERT(uio == UIO_WRITE || uio == UIO_READ);
	ASSERT(vp);
	ASSERT(vp->v_file);
	ASSERT(seg == UIO_SYSSPACE);
	ASSERT((ioflag & ~FAPPEND) == 0);
	ASSERT(x2 == RLIM64_INFINITY);

	fp = vp->v_file;

	offset = off;
	if (ioflag & FAPPEND)
		offset = fp->f_pos;

	/* Writable user data segment must be briefly increased for this
	 * process so we can use the user space read call paths to write
	 * in to memory allocated by the kernel. */
	saved_fs = get_fs();
        set_fs(get_ds());

	if (uio & UIO_WRITE)
		rc = vfs_write(fp, addr, len, &offset);
	else
		rc = vfs_read(fp, addr, len, &offset);

	set_fs(saved_fs);
	fp->f_pos = offset;

	if (rc < 0)
		return (-rc);

	if (residp) {
		*residp = len - rc;
	} else {
		if (rc != len)
			return (EIO);
	}

	return (0);
} /* vn_rdwr() */
EXPORT_SYMBOL(vn_rdwr);

int
vn_close(vnode_t *vp, int flags, int x1, int x2, void *x3, void *x4)
{
	int rc;

	ASSERT(vp);
	ASSERT(vp->v_file);

	mapping_set_gfp_mask(vp->v_file->f_mapping, vp->v_gfp_mask);
	rc = filp_close(vp->v_file, 0);
	vn_free(vp);

	return (-rc);
} /* vn_close() */
EXPORT_SYMBOL(vn_close);

/* vn_seek() does not actually seek it only performs bounds checking on the
 * proposed seek.  We perform minimal checking and allow vn_rdwr() to catch
 * anything more serious. */
int
vn_seek(vnode_t *vp, offset_t ooff, offset_t *noffp, void *ct)
{
	return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
}
EXPORT_SYMBOL(vn_seek);

/*
 * spl_basename() takes a NULL-terminated string s as input containing a path.
 * It returns a char pointer to a string and a length that describe the
 * basename of the path. If the basename is not "." or "/", it will be an index
 * into the string. While the string should be NULL terminated, the section
 * referring to the basename is not. spl_basename is dual-licensed GPLv2+ and
 * CC0. Anyone wishing to reuse it in another codebase may pick either license.
 */
static void
spl_basename(const char *s, const char **str, int *len)
{
	size_t i, end;

	ASSERT(str);
	ASSERT(len);

	if (!s || !*s) {
		*str = ".";
		*len = 1;
		return;
	}

	i = strlen(s) - 1;

	while (i && s[i--] == '/');

	if (i == 0) {
		*str = "/";
		*len = 1;
		return;
	}

	end = i;

	for (end = i; i; i--) {
		if (s[i] == '/') {
			*str = &s[i+1];
			*len = end - i + 1;
			return;
		}
	}

	*str = s;
	*len = end + 1;
}

static struct dentry *
spl_kern_path_locked(const char *name, struct path *path)
{
	struct path parent;
	struct dentry *dentry;
	const char *basename;
	int len;
	int rc;

	ASSERT(name);
	ASSERT(path);

	spl_basename(name, &basename, &len);

	/* We do not accept "." or ".." */
	if (len <= 2 && basename[0] == '.')
		if (len == 1 || basename[1] == '.')
			return (ERR_PTR(-EACCES));

	rc = kern_path(name, LOOKUP_PARENT, &parent);
	if (rc)
		return (ERR_PTR(rc));

	spl_inode_lock(parent.dentry->d_inode);

	dentry = lookup_one_len(basename, parent.dentry, len);
	if (IS_ERR(dentry)) {
		spl_inode_unlock(parent.dentry->d_inode);
		path_put(&parent);
	} else {
		*path = parent;
	}

	return (dentry);
}

/* Based on do_unlinkat() from linux/fs/namei.c */
int
vn_remove(const char *path, uio_seg_t seg, int flags)
{
	struct dentry *dentry;
	struct path parent;
	struct inode *inode = NULL;
	int rc = 0;

	ASSERT(seg == UIO_SYSSPACE);
	ASSERT(flags == RMFILE);

	dentry = spl_kern_path_locked(path, &parent);
	rc = PTR_ERR(dentry);
	if (!IS_ERR(dentry)) {
		if (parent.dentry->d_name.name[parent.dentry->d_name.len]) {
			rc = 0;
			goto slashes;
		}

		inode = dentry->d_inode;
		if (inode) {
			atomic_inc(&inode->i_count);
		} else {
			rc = 0;
			goto slashes;
		}

#ifdef HAVE_2ARGS_VFS_UNLINK
		rc = vfs_unlink(parent.dentry->d_inode, dentry);
#else
		rc = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
#endif /* HAVE_2ARGS_VFS_UNLINK */
exit1:
		dput(dentry);
	} else {
		return (-rc);
	}

	spl_inode_unlock(parent.dentry->d_inode);
	if (inode)
		iput(inode);    /* truncate the inode here */

	path_put(&parent);
	return (-rc);

slashes:
	rc = !dentry->d_inode ? -ENOENT :
	    S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR;
	goto exit1;
} /* vn_remove() */
EXPORT_SYMBOL(vn_remove);

/* Based on do_rename() from linux/fs/namei.c */
int
vn_rename(const char *oldname, const char *newname, int x1)
{
	struct dentry *old_dir, *new_dir;
	struct dentry *old_dentry, *new_dentry;
	struct dentry *trap;
	struct path old_parent, new_parent;
	int rc = 0;

	old_dentry = spl_kern_path_locked(oldname, &old_parent);
	if (IS_ERR(old_dentry)) {
		rc = PTR_ERR(old_dentry);
		goto exit;
	}

	spl_inode_unlock(old_parent.dentry->d_inode);

	new_dentry = spl_kern_path_locked(newname, &new_parent);
	if (IS_ERR(new_dentry)) {
		rc = PTR_ERR(new_dentry);
		goto exit2;
	}

	spl_inode_unlock(new_parent.dentry->d_inode);

	rc = -EXDEV;
	if (old_parent.mnt != new_parent.mnt)
		goto exit3;

	old_dir = old_parent.dentry;
	new_dir = new_parent.dentry;
	trap = lock_rename(new_dir, old_dir);

	/* source should not be ancestor of target */
	rc = -EINVAL;
	if (old_dentry == trap)
		goto exit4;

	/* target should not be an ancestor of source */
	rc = -ENOTEMPTY;
	if (new_dentry == trap)
		goto exit4;

	/* source must exist */
	rc = -ENOENT;
	if (!old_dentry->d_inode)
		goto exit4;

	/* unless the source is a directory trailing slashes give -ENOTDIR */
	if (!S_ISDIR(old_dentry->d_inode->i_mode)) {
		rc = -ENOTDIR;
		if (old_dentry->d_name.name[old_dentry->d_name.len])
			goto exit4;
		if (new_dentry->d_name.name[new_dentry->d_name.len])
			goto exit4;
	}

#if defined(HAVE_4ARGS_VFS_RENAME)
	rc = vfs_rename(old_dir->d_inode, old_dentry,
	    new_dir->d_inode, new_dentry);
#elif defined(HAVE_5ARGS_VFS_RENAME)
	rc = vfs_rename(old_dir->d_inode, old_dentry,
	    new_dir->d_inode, new_dentry, NULL);
#else
	rc = vfs_rename(old_dir->d_inode, old_dentry,
	    new_dir->d_inode, new_dentry, NULL, 0);
#endif
exit4:
	unlock_rename(new_dir, old_dir);
exit3:
	dput(new_dentry);
	path_put(&new_parent);
exit2:
	dput(old_dentry);
	path_put(&old_parent);
exit:
	return (-rc);
}
EXPORT_SYMBOL(vn_rename);

int
vn_getattr(vnode_t *vp, vattr_t *vap, int flags, void *x3, void *x4)
{
	struct file *fp;
	struct kstat stat;
	int rc;

	ASSERT(vp);
	ASSERT(vp->v_file);
	ASSERT(vap);

	fp = vp->v_file;

#ifdef HAVE_2ARGS_VFS_GETATTR
	rc = vfs_getattr(&fp->f_path, &stat);
#else
	rc = vfs_getattr(fp->f_path.mnt, fp->f_dentry, &stat);
#endif
	if (rc)
		return (-rc);

	vap->va_type          = vn_mode_to_vtype(stat.mode);
	vap->va_mode          = stat.mode;
	vap->va_uid           = KUID_TO_SUID(stat.uid);
	vap->va_gid           = KGID_TO_SGID(stat.gid);
	vap->va_fsid          = 0;
	vap->va_nodeid        = stat.ino;
	vap->va_nlink         = stat.nlink;
        vap->va_size          = stat.size;
	vap->va_blksize       = stat.blksize;
	vap->va_atime         = stat.atime;
	vap->va_mtime         = stat.mtime;
	vap->va_ctime         = stat.ctime;
	vap->va_rdev          = stat.rdev;
	vap->va_nblocks       = stat.blocks;

	return (0);
}
EXPORT_SYMBOL(vn_getattr);

int vn_fsync(vnode_t *vp, int flags, void *x3, void *x4)
{
	int datasync = 0;
	int error;
	int fstrans;

	ASSERT(vp);
	ASSERT(vp->v_file);

	if (flags & FDSYNC)
		datasync = 1;

	/*
	 * May enter XFS which generates a warning when PF_FSTRANS is set.
	 * To avoid this the flag is cleared over vfs_sync() and then reset.
	 */
	fstrans = spl_fstrans_check();
	if (fstrans)
		current->flags &= ~(PF_FSTRANS);

	error = -spl_filp_fsync(vp->v_file, datasync);
	if (fstrans)
		current->flags |= PF_FSTRANS;

	return (error);
} /* vn_fsync() */
EXPORT_SYMBOL(vn_fsync);

int vn_space(vnode_t *vp, int cmd, struct flock *bfp, int flag,
    offset_t offset, void *x6, void *x7)
{
	int error = EOPNOTSUPP;

	if (cmd != F_FREESP || bfp->l_whence != 0)
		return (EOPNOTSUPP);

	ASSERT(vp);
	ASSERT(vp->v_file);
	ASSERT(bfp->l_start >= 0 && bfp->l_len > 0);

#ifdef FALLOC_FL_PUNCH_HOLE
	/*
	 * When supported by the underlying file system preferentially
	 * use the fallocate() callback to preallocate the space.
	 */
	error = -spl_filp_fallocate(vp->v_file,
	    FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE,
	    bfp->l_start, bfp->l_len);
	if (error == 0)
		return (0);
#endif

#ifdef HAVE_INODE_TRUNCATE_RANGE
	if (vp->v_file->f_dentry && vp->v_file->f_dentry->d_inode &&
	    vp->v_file->f_dentry->d_inode->i_op &&
	    vp->v_file->f_dentry->d_inode->i_op->truncate_range) {
		off_t end = bfp->l_start + bfp->l_len;
		/*
		 * Judging from the code in shmem_truncate_range(),
		 * it seems the kernel expects the end offset to be
		 * inclusive and aligned to the end of a page.
		 */
		if (end % PAGE_SIZE != 0) {
			end &= ~(off_t)(PAGE_SIZE - 1);
			if (end <= bfp->l_start)
				return (0);
		}
		--end;

		vp->v_file->f_dentry->d_inode->i_op->truncate_range(
			vp->v_file->f_dentry->d_inode,
			bfp->l_start, end
		);
		return (0);
	}
#endif

	return (error);
}
EXPORT_SYMBOL(vn_space);

/* Function must be called while holding the vn_file_lock */
static file_t *
file_find(int fd)
{
        file_t *fp;

	ASSERT(spin_is_locked(&vn_file_lock));

        list_for_each_entry(fp, &vn_file_list,  f_list) {
		if (fd == fp->f_fd && fp->f_task == current) {
			ASSERT(atomic_read(&fp->f_ref) != 0);
                        return fp;
		}
	}

        return NULL;
} /* file_find() */

file_t *
vn_getf(int fd)
{
        struct kstat stat;
	struct file *lfp;
	file_t *fp;
	vnode_t *vp;
	int rc = 0;

	/* Already open just take an extra reference */
	spin_lock(&vn_file_lock);

	fp = file_find(fd);
	if (fp) {
		atomic_inc(&fp->f_ref);
		spin_unlock(&vn_file_lock);
		return (fp);
	}

	spin_unlock(&vn_file_lock);

	/* File was not yet opened create the object and setup */
	fp = kmem_cache_alloc(vn_file_cache, KM_SLEEP);
	if (fp == NULL)
		goto out;

	mutex_enter(&fp->f_lock);

	fp->f_fd = fd;
	fp->f_task = current;
	fp->f_offset = 0;
	atomic_inc(&fp->f_ref);

	lfp = fget(fd);
	if (lfp == NULL)
		goto out_mutex;

	vp = vn_alloc(KM_SLEEP);
	if (vp == NULL)
		goto out_fget;

#ifdef HAVE_2ARGS_VFS_GETATTR
	rc = vfs_getattr(&lfp->f_path, &stat);
#else
	rc = vfs_getattr(lfp->f_path.mnt, lfp->f_dentry, &stat);
#endif
        if (rc)
		goto out_vnode;

	mutex_enter(&vp->v_lock);
	vp->v_type = vn_mode_to_vtype(stat.mode);
	vp->v_file = lfp;
	mutex_exit(&vp->v_lock);

	fp->f_vnode = vp;
	fp->f_file = lfp;

	/* Put it on the tracking list */
	spin_lock(&vn_file_lock);
	list_add(&fp->f_list, &vn_file_list);
	spin_unlock(&vn_file_lock);

	mutex_exit(&fp->f_lock);
	return (fp);

out_vnode:
	vn_free(vp);
out_fget:
	fput(lfp);
out_mutex:
	mutex_exit(&fp->f_lock);
	kmem_cache_free(vn_file_cache, fp);
out:
        return (NULL);
} /* getf() */
EXPORT_SYMBOL(getf);

static void releasef_locked(file_t *fp)
{
	ASSERT(fp->f_file);
	ASSERT(fp->f_vnode);

	/* Unlinked from list, no refs, safe to free outside mutex */
	fput(fp->f_file);
	vn_free(fp->f_vnode);

	kmem_cache_free(vn_file_cache, fp);
}

void
vn_releasef(int fd)
{
	file_t *fp;

	spin_lock(&vn_file_lock);
	fp = file_find(fd);
	if (fp) {
		atomic_dec(&fp->f_ref);
		if (atomic_read(&fp->f_ref) > 0) {
			spin_unlock(&vn_file_lock);
			return;
		}

	        list_del(&fp->f_list);
		releasef_locked(fp);
	}
	spin_unlock(&vn_file_lock);

	return;
} /* releasef() */
EXPORT_SYMBOL(releasef);

static void
#ifdef HAVE_SET_FS_PWD_WITH_CONST
vn_set_fs_pwd(struct fs_struct *fs, const struct path *path)
#else
vn_set_fs_pwd(struct fs_struct *fs, struct path *path)
#endif /* HAVE_SET_FS_PWD_WITH_CONST */
{
	struct path old_pwd;

#ifdef HAVE_FS_STRUCT_SPINLOCK
	spin_lock(&fs->lock);
	old_pwd = fs->pwd;
	fs->pwd = *path;
	path_get(path);
	spin_unlock(&fs->lock);
#else
	write_lock(&fs->lock);
	old_pwd = fs->pwd;
	fs->pwd = *path;
	path_get(path);
	write_unlock(&fs->lock);
#endif /* HAVE_FS_STRUCT_SPINLOCK */

	if (old_pwd.dentry)
		path_put(&old_pwd);
}

int
vn_set_pwd(const char *filename)
{
        struct path path;
        mm_segment_t saved_fs;
        int rc;

        /*
         * user_path_dir() and __user_walk() both expect 'filename' to be
         * a user space address so we must briefly increase the data segment
         * size to ensure strncpy_from_user() does not fail with -EFAULT.
         */
        saved_fs = get_fs();
        set_fs(get_ds());

        rc = user_path_dir(filename, &path);
        if (rc)
		goto out;

        rc = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_ACCESS);
        if (rc)
		goto dput_and_out;

        vn_set_fs_pwd(current->fs, &path);

dput_and_out:
        path_put(&path);
out:
	set_fs(saved_fs);

        return (-rc);
} /* vn_set_pwd() */
EXPORT_SYMBOL(vn_set_pwd);

static int
vn_cache_constructor(void *buf, void *cdrarg, int kmflags)
{
	struct vnode *vp = buf;

	mutex_init(&vp->v_lock, NULL, MUTEX_DEFAULT, NULL);

	return (0);
} /* vn_cache_constructor() */

static void
vn_cache_destructor(void *buf, void *cdrarg)
{
	struct vnode *vp = buf;

	mutex_destroy(&vp->v_lock);
} /* vn_cache_destructor() */

static int
vn_file_cache_constructor(void *buf, void *cdrarg, int kmflags)
{
	file_t *fp = buf;

	atomic_set(&fp->f_ref, 0);
        mutex_init(&fp->f_lock, NULL, MUTEX_DEFAULT, NULL);
	INIT_LIST_HEAD(&fp->f_list);

        return (0);
} /* file_cache_constructor() */

static void
vn_file_cache_destructor(void *buf, void *cdrarg)
{
	file_t *fp = buf;

	mutex_destroy(&fp->f_lock);
} /* vn_file_cache_destructor() */

int
spl_vn_init(void)
{
	vn_cache = kmem_cache_create("spl_vn_cache",
				     sizeof(struct vnode), 64,
	                             vn_cache_constructor,
				     vn_cache_destructor,
				     NULL, NULL, NULL, KMC_KMEM);

	vn_file_cache = kmem_cache_create("spl_vn_file_cache",
					  sizeof(file_t), 64,
				          vn_file_cache_constructor,
				          vn_file_cache_destructor,
				          NULL, NULL, NULL, KMC_KMEM);
	return (0);
} /* vn_init() */

void
spl_vn_fini(void)
{
        file_t *fp, *next_fp;
	int leaked = 0;

	spin_lock(&vn_file_lock);

        list_for_each_entry_safe(fp, next_fp, &vn_file_list,  f_list) {
	        list_del(&fp->f_list);
		releasef_locked(fp);
		leaked++;
	}

	spin_unlock(&vn_file_lock);

	if (leaked > 0)
		printk(KERN_WARNING "WARNING: %d vnode files leaked\n", leaked);

	kmem_cache_destroy(vn_file_cache);
	kmem_cache_destroy(vn_cache);

	return;
} /* vn_fini() */