linux_stats.c revision 293592
1/*-
2 * Copyright (c) 1994-1995 S��ren Schmidt
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/10/sys/compat/linux/linux_stats.c 293592 2016-01-09 17:54:37Z dchagin $");
31
32#include "opt_compat.h"
33
34#include <sys/param.h>
35#include <sys/capsicum.h>
36#include <sys/dirent.h>
37#include <sys/file.h>
38#include <sys/filedesc.h>
39#include <sys/proc.h>
40#include <sys/malloc.h>
41#include <sys/mount.h>
42#include <sys/namei.h>
43#include <sys/stat.h>
44#include <sys/syscallsubr.h>
45#include <sys/systm.h>
46#include <sys/tty.h>
47#include <sys/vnode.h>
48#include <sys/conf.h>
49#include <sys/fcntl.h>
50
51#ifdef COMPAT_LINUX32
52#include <machine/../linux32/linux.h>
53#include <machine/../linux32/linux32_proto.h>
54#else
55#include <machine/../linux/linux.h>
56#include <machine/../linux/linux_proto.h>
57#endif
58
59#include <compat/linux/linux_util.h>
60#include <compat/linux/linux_file.h>
61
62
63static void
64translate_vnhook_major_minor(struct vnode *vp, struct stat *sb)
65{
66	int major, minor;
67
68	if (vp->v_type == VCHR && vp->v_rdev != NULL &&
69	    linux_driver_get_major_minor(devtoname(vp->v_rdev),
70	    &major, &minor) == 0) {
71		sb->st_rdev = (major << 8 | minor);
72	}
73}
74
75static int
76linux_kern_statat(struct thread *td, int flag, int fd, char *path,
77    enum uio_seg pathseg, struct stat *sbp)
78{
79
80	return (kern_statat_vnhook(td, flag, fd, path, pathseg, sbp,
81	    translate_vnhook_major_minor));
82}
83
84static int
85linux_kern_stat(struct thread *td, char *path, enum uio_seg pathseg,
86    struct stat *sbp)
87{
88
89	return (linux_kern_statat(td, 0, AT_FDCWD, path, pathseg, sbp));
90}
91
92static int
93linux_kern_lstat(struct thread *td, char *path, enum uio_seg pathseg,
94    struct stat *sbp)
95{
96
97	return (linux_kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, path,
98	    pathseg, sbp));
99}
100
101/*
102 * XXX: This was removed from newstat_copyout(), and almost identical
103 * XXX: code was in stat64_copyout().  findcdev() needs to be replaced
104 * XXX: with something that does lookup and locking properly.
105 * XXX: When somebody fixes this: please try to avoid duplicating it.
106 */
107#if 0
108static void
109disk_foo(struct somestat *tbuf)
110{
111	struct cdevsw *cdevsw;
112	struct cdev *dev;
113
114	/* Lie about disk drives which are character devices
115	 * in FreeBSD but block devices under Linux.
116	 */
117	if (S_ISCHR(tbuf.st_mode) &&
118	    (dev = findcdev(buf->st_rdev)) != NULL) {
119		cdevsw = dev_refthread(dev);
120		if (cdevsw != NULL) {
121			if (cdevsw->d_flags & D_DISK) {
122				tbuf.st_mode &= ~S_IFMT;
123				tbuf.st_mode |= S_IFBLK;
124
125				/* XXX this may not be quite right */
126				/* Map major number to 0 */
127				tbuf.st_dev = minor(buf->st_dev) & 0xf;
128				tbuf.st_rdev = buf->st_rdev & 0xff;
129			}
130			dev_relthread(dev);
131		}
132	}
133
134}
135#endif
136
137static void
138translate_fd_major_minor(struct thread *td, int fd, struct stat *buf)
139{
140	struct file *fp;
141	struct vnode *vp;
142	int major, minor;
143
144	/*
145	 * No capability rights required here.
146	 */
147	if ((!S_ISCHR(buf->st_mode) && !S_ISBLK(buf->st_mode)) ||
148	    fget(td, fd, 0, &fp) != 0)
149		return;
150	vp = fp->f_vnode;
151	if (vp != NULL && vp->v_rdev != NULL &&
152	    linux_driver_get_major_minor(devtoname(vp->v_rdev),
153					 &major, &minor) == 0) {
154		buf->st_rdev = (major << 8 | minor);
155	} else if (fp->f_type == DTYPE_PTS) {
156		struct tty *tp = fp->f_data;
157
158		/* Convert the numbers for the slave device. */
159		if (linux_driver_get_major_minor(devtoname(tp->t_dev),
160					 &major, &minor) == 0) {
161			buf->st_rdev = (major << 8 | minor);
162		}
163	}
164	fdrop(fp, td);
165}
166
167static int
168newstat_copyout(struct stat *buf, void *ubuf)
169{
170	struct l_newstat tbuf;
171
172	bzero(&tbuf, sizeof(tbuf));
173	tbuf.st_dev = minor(buf->st_dev) | (major(buf->st_dev) << 8);
174	tbuf.st_ino = buf->st_ino;
175	tbuf.st_mode = buf->st_mode;
176	tbuf.st_nlink = buf->st_nlink;
177	tbuf.st_uid = buf->st_uid;
178	tbuf.st_gid = buf->st_gid;
179	tbuf.st_rdev = buf->st_rdev;
180	tbuf.st_size = buf->st_size;
181	tbuf.st_atim.tv_sec = buf->st_atim.tv_sec;
182	tbuf.st_atim.tv_nsec = buf->st_atim.tv_nsec;
183	tbuf.st_mtim.tv_sec = buf->st_mtim.tv_sec;
184	tbuf.st_mtim.tv_nsec = buf->st_mtim.tv_nsec;
185	tbuf.st_ctim.tv_sec = buf->st_ctim.tv_sec;
186	tbuf.st_ctim.tv_nsec = buf->st_ctim.tv_nsec;
187	tbuf.st_blksize = buf->st_blksize;
188	tbuf.st_blocks = buf->st_blocks;
189
190	return (copyout(&tbuf, ubuf, sizeof(tbuf)));
191}
192
193int
194linux_newstat(struct thread *td, struct linux_newstat_args *args)
195{
196	struct stat buf;
197	char *path;
198	int error;
199
200	LCONVPATHEXIST(td, args->path, &path);
201
202#ifdef DEBUG
203	if (ldebug(newstat))
204		printf(ARGS(newstat, "%s, *"), path);
205#endif
206
207	error = linux_kern_stat(td, path, UIO_SYSSPACE, &buf);
208	LFREEPATH(path);
209	if (error)
210		return (error);
211	return (newstat_copyout(&buf, args->buf));
212}
213
214int
215linux_newlstat(struct thread *td, struct linux_newlstat_args *args)
216{
217	struct stat sb;
218	char *path;
219	int error;
220
221	LCONVPATHEXIST(td, args->path, &path);
222
223#ifdef DEBUG
224	if (ldebug(newlstat))
225		printf(ARGS(newlstat, "%s, *"), path);
226#endif
227
228	error = linux_kern_lstat(td, path, UIO_SYSSPACE, &sb);
229	LFREEPATH(path);
230	if (error)
231		return (error);
232	return (newstat_copyout(&sb, args->buf));
233}
234
235int
236linux_newfstat(struct thread *td, struct linux_newfstat_args *args)
237{
238	struct stat buf;
239	int error;
240
241#ifdef DEBUG
242	if (ldebug(newfstat))
243		printf(ARGS(newfstat, "%d, *"), args->fd);
244#endif
245
246	error = kern_fstat(td, args->fd, &buf);
247	translate_fd_major_minor(td, args->fd, &buf);
248	if (!error)
249		error = newstat_copyout(&buf, args->buf);
250
251	return (error);
252}
253
254#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
255static int
256stat_copyout(struct stat *buf, void *ubuf)
257{
258	struct l_stat lbuf;
259
260	bzero(&lbuf, sizeof(lbuf));
261	lbuf.st_dev = buf->st_dev;
262	lbuf.st_ino = buf->st_ino;
263	lbuf.st_mode = buf->st_mode;
264	lbuf.st_nlink = buf->st_nlink;
265	lbuf.st_uid = buf->st_uid;
266	lbuf.st_gid = buf->st_gid;
267	lbuf.st_rdev = buf->st_rdev;
268	if (buf->st_size < (quad_t)1 << 32)
269		lbuf.st_size = buf->st_size;
270	else
271		lbuf.st_size = -2;
272	lbuf.st_atim.tv_sec = buf->st_atim.tv_sec;
273	lbuf.st_atim.tv_nsec = buf->st_atim.tv_nsec;
274	lbuf.st_mtim.tv_sec = buf->st_mtim.tv_sec;
275	lbuf.st_mtim.tv_nsec = buf->st_mtim.tv_nsec;
276	lbuf.st_ctim.tv_sec = buf->st_ctim.tv_sec;
277	lbuf.st_ctim.tv_nsec = buf->st_ctim.tv_nsec;
278	lbuf.st_blksize = buf->st_blksize;
279	lbuf.st_blocks = buf->st_blocks;
280	lbuf.st_flags = buf->st_flags;
281	lbuf.st_gen = buf->st_gen;
282
283	return (copyout(&lbuf, ubuf, sizeof(lbuf)));
284}
285
286int
287linux_stat(struct thread *td, struct linux_stat_args *args)
288{
289	struct stat buf;
290	char *path;
291	int error;
292
293	LCONVPATHEXIST(td, args->path, &path);
294
295#ifdef DEBUG
296	if (ldebug(stat))
297		printf(ARGS(stat, "%s, *"), path);
298#endif
299	error = linux_kern_stat(td, path, UIO_SYSSPACE, &buf);
300	if (error) {
301		LFREEPATH(path);
302		return (error);
303	}
304	LFREEPATH(path);
305	return(stat_copyout(&buf, args->up));
306}
307
308int
309linux_lstat(struct thread *td, struct linux_lstat_args *args)
310{
311	struct stat buf;
312	char *path;
313	int error;
314
315	LCONVPATHEXIST(td, args->path, &path);
316
317#ifdef DEBUG
318	if (ldebug(lstat))
319		printf(ARGS(lstat, "%s, *"), path);
320#endif
321	error = linux_kern_lstat(td, path, UIO_SYSSPACE, &buf);
322	if (error) {
323		LFREEPATH(path);
324		return (error);
325	}
326	LFREEPATH(path);
327	return(stat_copyout(&buf, args->up));
328}
329#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
330
331struct l_statfs {
332	l_long		f_type;
333	l_long		f_bsize;
334	l_long		f_blocks;
335	l_long		f_bfree;
336	l_long		f_bavail;
337	l_long		f_files;
338	l_long		f_ffree;
339	l_fsid_t	f_fsid;
340	l_long		f_namelen;
341	l_long		f_spare[6];
342};
343
344#define	LINUX_CODA_SUPER_MAGIC	0x73757245L
345#define	LINUX_EXT2_SUPER_MAGIC	0xEF53L
346#define	LINUX_HPFS_SUPER_MAGIC	0xf995e849L
347#define	LINUX_ISOFS_SUPER_MAGIC	0x9660L
348#define	LINUX_MSDOS_SUPER_MAGIC	0x4d44L
349#define	LINUX_NCP_SUPER_MAGIC	0x564cL
350#define	LINUX_NFS_SUPER_MAGIC	0x6969L
351#define	LINUX_NTFS_SUPER_MAGIC	0x5346544EL
352#define	LINUX_PROC_SUPER_MAGIC	0x9fa0L
353#define	LINUX_UFS_SUPER_MAGIC	0x00011954L	/* XXX - UFS_MAGIC in Linux */
354#define LINUX_DEVFS_SUPER_MAGIC	0x1373L
355#define	LINUX_SHMFS_MAGIC	0x01021994
356
357static long
358bsd_to_linux_ftype(const char *fstypename)
359{
360	int i;
361	static struct {const char *bsd_name; long linux_type;} b2l_tbl[] = {
362		{"ufs",     LINUX_UFS_SUPER_MAGIC},
363		{"cd9660",  LINUX_ISOFS_SUPER_MAGIC},
364		{"nfs",     LINUX_NFS_SUPER_MAGIC},
365		{"ext2fs",  LINUX_EXT2_SUPER_MAGIC},
366		{"procfs",  LINUX_PROC_SUPER_MAGIC},
367		{"msdosfs", LINUX_MSDOS_SUPER_MAGIC},
368		{"ntfs",    LINUX_NTFS_SUPER_MAGIC},
369		{"nwfs",    LINUX_NCP_SUPER_MAGIC},
370		{"hpfs",    LINUX_HPFS_SUPER_MAGIC},
371		{"coda",    LINUX_CODA_SUPER_MAGIC},
372		{"devfs",   LINUX_DEVFS_SUPER_MAGIC},
373		{"tmpfs",   LINUX_SHMFS_MAGIC},
374		{NULL,      0L}};
375
376	for (i = 0; b2l_tbl[i].bsd_name != NULL; i++)
377		if (strcmp(b2l_tbl[i].bsd_name, fstypename) == 0)
378			return (b2l_tbl[i].linux_type);
379
380	return (0L);
381}
382
383static void
384bsd_to_linux_statfs(struct statfs *bsd_statfs, struct l_statfs *linux_statfs)
385{
386
387	linux_statfs->f_type = bsd_to_linux_ftype(bsd_statfs->f_fstypename);
388	linux_statfs->f_bsize = bsd_statfs->f_bsize;
389	linux_statfs->f_blocks = bsd_statfs->f_blocks;
390	linux_statfs->f_bfree = bsd_statfs->f_bfree;
391	linux_statfs->f_bavail = bsd_statfs->f_bavail;
392	linux_statfs->f_ffree = bsd_statfs->f_ffree;
393	linux_statfs->f_files = bsd_statfs->f_files;
394	linux_statfs->f_fsid.val[0] = bsd_statfs->f_fsid.val[0];
395	linux_statfs->f_fsid.val[1] = bsd_statfs->f_fsid.val[1];
396	linux_statfs->f_namelen = MAXNAMLEN;
397}
398
399int
400linux_statfs(struct thread *td, struct linux_statfs_args *args)
401{
402	struct l_statfs linux_statfs;
403	struct statfs bsd_statfs;
404	char *path;
405	int error;
406
407	LCONVPATHEXIST(td, args->path, &path);
408
409#ifdef DEBUG
410	if (ldebug(statfs))
411		printf(ARGS(statfs, "%s, *"), path);
412#endif
413	error = kern_statfs(td, path, UIO_SYSSPACE, &bsd_statfs);
414	LFREEPATH(path);
415	if (error)
416		return (error);
417	bsd_to_linux_statfs(&bsd_statfs, &linux_statfs);
418	return copyout(&linux_statfs, args->buf, sizeof(linux_statfs));
419}
420
421#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
422static void
423bsd_to_linux_statfs64(struct statfs *bsd_statfs, struct l_statfs64 *linux_statfs)
424{
425
426	linux_statfs->f_type = bsd_to_linux_ftype(bsd_statfs->f_fstypename);
427	linux_statfs->f_bsize = bsd_statfs->f_bsize;
428	linux_statfs->f_blocks = bsd_statfs->f_blocks;
429	linux_statfs->f_bfree = bsd_statfs->f_bfree;
430	linux_statfs->f_bavail = bsd_statfs->f_bavail;
431	linux_statfs->f_ffree = bsd_statfs->f_ffree;
432	linux_statfs->f_files = bsd_statfs->f_files;
433	linux_statfs->f_fsid.val[0] = bsd_statfs->f_fsid.val[0];
434	linux_statfs->f_fsid.val[1] = bsd_statfs->f_fsid.val[1];
435	linux_statfs->f_namelen = MAXNAMLEN;
436}
437
438int
439linux_statfs64(struct thread *td, struct linux_statfs64_args *args)
440{
441	struct l_statfs64 linux_statfs;
442	struct statfs bsd_statfs;
443	char *path;
444	int error;
445
446	if (args->bufsize != sizeof(struct l_statfs64))
447		return EINVAL;
448
449	LCONVPATHEXIST(td, args->path, &path);
450
451#ifdef DEBUG
452	if (ldebug(statfs64))
453		printf(ARGS(statfs64, "%s, *"), path);
454#endif
455	error = kern_statfs(td, path, UIO_SYSSPACE, &bsd_statfs);
456	LFREEPATH(path);
457	if (error)
458		return (error);
459	bsd_to_linux_statfs64(&bsd_statfs, &linux_statfs);
460	return copyout(&linux_statfs, args->buf, sizeof(linux_statfs));
461}
462#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
463
464int
465linux_fstatfs(struct thread *td, struct linux_fstatfs_args *args)
466{
467	struct l_statfs linux_statfs;
468	struct statfs bsd_statfs;
469	int error;
470
471#ifdef DEBUG
472	if (ldebug(fstatfs))
473		printf(ARGS(fstatfs, "%d, *"), args->fd);
474#endif
475	error = kern_fstatfs(td, args->fd, &bsd_statfs);
476	if (error)
477		return error;
478	bsd_to_linux_statfs(&bsd_statfs, &linux_statfs);
479	return copyout(&linux_statfs, args->buf, sizeof(linux_statfs));
480}
481
482struct l_ustat
483{
484	l_daddr_t	f_tfree;
485	l_ino_t		f_tinode;
486	char		f_fname[6];
487	char		f_fpack[6];
488};
489
490int
491linux_ustat(struct thread *td, struct linux_ustat_args *args)
492{
493#ifdef DEBUG
494	if (ldebug(ustat))
495		printf(ARGS(ustat, "%ju, *"), (uintmax_t)args->dev);
496#endif
497
498	return (EOPNOTSUPP);
499}
500
501#if defined(__i386__) || (defined(__amd64__) && defined(COMPAT_LINUX32))
502
503static int
504stat64_copyout(struct stat *buf, void *ubuf)
505{
506	struct l_stat64 lbuf;
507
508	bzero(&lbuf, sizeof(lbuf));
509	lbuf.st_dev = minor(buf->st_dev) | (major(buf->st_dev) << 8);
510	lbuf.st_ino = buf->st_ino;
511	lbuf.st_mode = buf->st_mode;
512	lbuf.st_nlink = buf->st_nlink;
513	lbuf.st_uid = buf->st_uid;
514	lbuf.st_gid = buf->st_gid;
515	lbuf.st_rdev = buf->st_rdev;
516	lbuf.st_size = buf->st_size;
517	lbuf.st_atim.tv_sec = buf->st_atim.tv_sec;
518	lbuf.st_atim.tv_nsec = buf->st_atim.tv_nsec;
519	lbuf.st_mtim.tv_sec = buf->st_mtim.tv_sec;
520	lbuf.st_mtim.tv_nsec = buf->st_mtim.tv_nsec;
521	lbuf.st_ctim.tv_sec = buf->st_ctim.tv_sec;
522	lbuf.st_ctim.tv_nsec = buf->st_ctim.tv_nsec;
523	lbuf.st_blksize = buf->st_blksize;
524	lbuf.st_blocks = buf->st_blocks;
525
526	/*
527	 * The __st_ino field makes all the difference. In the Linux kernel
528	 * it is conditionally compiled based on STAT64_HAS_BROKEN_ST_INO,
529	 * but without the assignment to __st_ino the runtime linker refuses
530	 * to mmap(2) any shared libraries. I guess it's broken alright :-)
531	 */
532	lbuf.__st_ino = buf->st_ino;
533
534	return (copyout(&lbuf, ubuf, sizeof(lbuf)));
535}
536
537int
538linux_stat64(struct thread *td, struct linux_stat64_args *args)
539{
540	struct stat buf;
541	char *filename;
542	int error;
543
544	LCONVPATHEXIST(td, args->filename, &filename);
545
546#ifdef DEBUG
547	if (ldebug(stat64))
548		printf(ARGS(stat64, "%s, *"), filename);
549#endif
550
551	error = linux_kern_stat(td, filename, UIO_SYSSPACE, &buf);
552	LFREEPATH(filename);
553	if (error)
554		return (error);
555	return (stat64_copyout(&buf, args->statbuf));
556}
557
558int
559linux_lstat64(struct thread *td, struct linux_lstat64_args *args)
560{
561	struct stat sb;
562	char *filename;
563	int error;
564
565	LCONVPATHEXIST(td, args->filename, &filename);
566
567#ifdef DEBUG
568	if (ldebug(lstat64))
569		printf(ARGS(lstat64, "%s, *"), args->filename);
570#endif
571
572	error = linux_kern_lstat(td, filename, UIO_SYSSPACE, &sb);
573	LFREEPATH(filename);
574	if (error)
575		return (error);
576	return (stat64_copyout(&sb, args->statbuf));
577}
578
579int
580linux_fstat64(struct thread *td, struct linux_fstat64_args *args)
581{
582	struct stat buf;
583	int error;
584
585#ifdef DEBUG
586	if (ldebug(fstat64))
587		printf(ARGS(fstat64, "%d, *"), args->fd);
588#endif
589
590	error = kern_fstat(td, args->fd, &buf);
591	translate_fd_major_minor(td, args->fd, &buf);
592	if (!error)
593		error = stat64_copyout(&buf, args->statbuf);
594
595	return (error);
596}
597
598int
599linux_fstatat64(struct thread *td, struct linux_fstatat64_args *args)
600{
601	char *path;
602	int error, dfd, flag;
603	struct stat buf;
604
605	if (args->flag & ~LINUX_AT_SYMLINK_NOFOLLOW)
606		return (EINVAL);
607	flag = (args->flag & LINUX_AT_SYMLINK_NOFOLLOW) ?
608	    AT_SYMLINK_NOFOLLOW : 0;
609
610	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
611	LCONVPATHEXIST_AT(td, args->pathname, &path, dfd);
612
613#ifdef DEBUG
614	if (ldebug(fstatat64))
615		printf(ARGS(fstatat64, "%i, %s, %i"), args->dfd, path, args->flag);
616#endif
617
618	error = linux_kern_statat(td, flag, dfd, path, UIO_SYSSPACE, &buf);
619	if (!error)
620		error = stat64_copyout(&buf, args->statbuf);
621	LFREEPATH(path);
622
623	return (error);
624}
625
626#else /* __amd64__ && !COMPAT_LINUX32 */
627
628int
629linux_newfstatat(struct thread *td, struct linux_newfstatat_args *args)
630{
631	char *path;
632	int error, dfd, flag;
633	struct stat buf;
634
635	if (args->flag & ~LINUX_AT_SYMLINK_NOFOLLOW)
636		return (EINVAL);
637	flag = (args->flag & LINUX_AT_SYMLINK_NOFOLLOW) ?
638	    AT_SYMLINK_NOFOLLOW : 0;
639
640	dfd = (args->dfd == LINUX_AT_FDCWD) ? AT_FDCWD : args->dfd;
641	LCONVPATHEXIST_AT(td, args->pathname, &path, dfd);
642
643#ifdef DEBUG
644	if (ldebug(newfstatat))
645		printf(ARGS(newfstatat, "%i, %s, %i"), args->dfd, path, args->flag);
646#endif
647
648	error = linux_kern_statat(td, flag, dfd, path, UIO_SYSSPACE, &buf);
649	if (error == 0)
650		error = newstat_copyout(&buf, args->statbuf);
651	LFREEPATH(path);
652
653	return (error);
654}
655
656#endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
657
658int
659linux_syncfs(struct thread *td, struct linux_syncfs_args *args)
660{
661	cap_rights_t rights;
662	struct mount *mp;
663	struct vnode *vp;
664	int error, save;
665
666	error = fgetvp(td, args->fd, cap_rights_init(&rights, CAP_FSYNC), &vp);
667	if (error != 0)
668		/*
669		 * Linux syncfs() returns only EBADF, however fgetvp()
670		 * can return EINVAL in case of file descriptor does
671		 * not represent a vnode. XXX.
672		 */
673		return (error);
674
675	mp = vp->v_mount;
676	mtx_lock(&mountlist_mtx);
677	error = vfs_busy(mp, MBF_MNTLSTLOCK);
678	if (error != 0) {
679		/* See comment above. */
680		mtx_unlock(&mountlist_mtx);
681		goto out;
682	}
683	if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
684	    vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
685		save = curthread_pflags_set(TDP_SYNCIO);
686		vfs_msync(mp, MNT_NOWAIT);
687		VFS_SYNC(mp, MNT_NOWAIT);
688		curthread_pflags_restore(save);
689		vn_finished_write(mp);
690	}
691	vfs_unbusy(mp);
692
693 out:
694	vrele(vp);
695	return (error);
696}
697