summaryrefslogtreecommitdiff
path: root/fs/gfs2/ops_file.c
blob: faa07e4b97d025709cc246a22d51fd367e2c6d89 (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
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/pagemap.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/gfs2_ondisk.h>
#include <linux/ext2_fs.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
#include <linux/writeback.h>
#include <asm/uaccess.h>

#include "gfs2.h"
#include "incore.h"
#include "bmap.h"
#include "dir.h"
#include "glock.h"
#include "glops.h"
#include "inode.h"
#include "lm.h"
#include "log.h"
#include "meta_io.h"
#include "ops_file.h"
#include "ops_vm.h"
#include "quota.h"
#include "rgrp.h"
#include "trans.h"
#include "util.h"
#include "eaops.h"

/* For regular, non-NFS */
struct filldir_reg {
	struct gfs2_sbd *fdr_sbd;
	int fdr_prefetch;

	filldir_t fdr_filldir;
	void *fdr_opaque;
};

/*
 * Most fields left uninitialised to catch anybody who tries to
 * use them. f_flags set to prevent file_accessed() from touching
 * any other part of this. Its use is purely as a flag so that we
 * know (in readpage()) whether or not do to locking.
 */
struct file gfs2_internal_file_sentinel = {
	.f_flags = O_NOATIME|O_RDONLY,
};

static int gfs2_read_actor(read_descriptor_t *desc, struct page *page,
			   unsigned long offset, unsigned long size)
{
	char *kaddr;
	unsigned long count = desc->count;

	if (size > count)
		size = count;

	kaddr = kmap(page);
	memcpy(desc->arg.data, kaddr + offset, size);
	kunmap(page);

	desc->count = count - size;
	desc->written += size;
	desc->arg.buf += size;
	return size;
}

int gfs2_internal_read(struct gfs2_inode *ip, struct file_ra_state *ra_state,
		       char *buf, loff_t *pos, unsigned size)
{
	struct inode *inode = &ip->i_inode;
	read_descriptor_t desc;
	desc.written = 0;
	desc.arg.data = buf;
	desc.count = size;
	desc.error = 0;
	do_generic_mapping_read(inode->i_mapping, ra_state,
				&gfs2_internal_file_sentinel, pos, &desc,
				gfs2_read_actor);
	return desc.written ? desc.written : desc.error;
}

/**
 * gfs2_llseek - seek to a location in a file
 * @file: the file
 * @offset: the offset
 * @origin: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
 *
 * SEEK_END requires the glock for the file because it references the
 * file's size.
 *
 * Returns: The new offset, or errno
 */

static loff_t gfs2_llseek(struct file *file, loff_t offset, int origin)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_holder i_gh;
	loff_t error;

	if (origin == 2) {
		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (!error) {
			error = remote_llseek(file, offset, origin);
			gfs2_glock_dq_uninit(&i_gh);
		}
	} else
		error = remote_llseek(file, offset, origin);

	return error;
}

/**
 * filldir_func - Report a directory entry to the caller of gfs2_dir_read()
 * @opaque: opaque data used by the function
 * @name: the name of the directory entry
 * @length: the length of the name
 * @offset: the entry's offset in the directory
 * @inum: the inode number the entry points to
 * @type: the type of inode the entry points to
 *
 * Returns: 0 on success, 1 if buffer full
 */

static int filldir_func(void *opaque, const char *name, unsigned int length,
			u64 offset, struct gfs2_inum_host *inum,
			unsigned int type)
{
	struct filldir_reg *fdr = (struct filldir_reg *)opaque;
	struct gfs2_sbd *sdp = fdr->fdr_sbd;
	int error;

	error = fdr->fdr_filldir(fdr->fdr_opaque, name, length, offset,
				 inum->no_addr, type);
	if (error)
		return 1;

	if (fdr->fdr_prefetch && !(length == 1 && *name == '.')) {
		gfs2_glock_prefetch_num(sdp, inum->no_addr, &gfs2_inode_glops,
				       LM_ST_SHARED, LM_FLAG_TRY | LM_FLAG_ANY);
		gfs2_glock_prefetch_num(sdp, inum->no_addr, &gfs2_iopen_glops,
				       LM_ST_SHARED, LM_FLAG_TRY);
	}

	return 0;
}

/**
 * gfs2_readdir - Read directory entries from a directory
 * @file: The directory to read from
 * @dirent: Buffer for dirents
 * @filldir: Function used to do the copying
 *
 * Returns: errno
 */

static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
{
	struct inode *dir = file->f_mapping->host;
	struct gfs2_inode *dip = GFS2_I(dir);
	struct filldir_reg fdr;
	struct gfs2_holder d_gh;
	u64 offset = file->f_pos;
	int error;

	fdr.fdr_sbd = GFS2_SB(dir);
	fdr.fdr_prefetch = 1;
	fdr.fdr_filldir = filldir;
	fdr.fdr_opaque = dirent;

	gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
	error = gfs2_glock_nq_atime(&d_gh);
	if (error) {
		gfs2_holder_uninit(&d_gh);
		return error;
	}

	error = gfs2_dir_read(dir, &offset, &fdr, filldir_func);

	gfs2_glock_dq_uninit(&d_gh);

	file->f_pos = offset;

	return error;
}

/**
 * fsflags_cvt
 * @table: A table of 32 u32 flags
 * @val: a 32 bit value to convert
 *
 * This function can be used to convert between fsflags values and
 * GFS2's own flags values.
 *
 * Returns: the converted flags
 */
static u32 fsflags_cvt(const u32 *table, u32 val)
{
	u32 res = 0;
	while(val) {
		if (val & 1)
			res |= *table;
		table++;
		val >>= 1;
	}
	return res;
}

static const u32 fsflags_to_gfs2[32] = {
	[3] = GFS2_DIF_SYNC,
	[4] = GFS2_DIF_IMMUTABLE,
	[5] = GFS2_DIF_APPENDONLY,
	[7] = GFS2_DIF_NOATIME,
	[12] = GFS2_DIF_EXHASH,
	[14] = GFS2_DIF_JDATA,
	[20] = GFS2_DIF_DIRECTIO,
};

static const u32 gfs2_to_fsflags[32] = {
	[gfs2fl_Sync] = FS_SYNC_FL,
	[gfs2fl_Immutable] = FS_IMMUTABLE_FL,
	[gfs2fl_AppendOnly] = FS_APPEND_FL,
	[gfs2fl_NoAtime] = FS_NOATIME_FL,
	[gfs2fl_ExHash] = FS_INDEX_FL,
	[gfs2fl_Jdata] = FS_JOURNAL_DATA_FL,
	[gfs2fl_Directio] = FS_DIRECTIO_FL,
	[gfs2fl_InheritDirectio] = FS_DIRECTIO_FL,
	[gfs2fl_InheritJdata] = FS_JOURNAL_DATA_FL,
};

static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int error;
	u32 fsflags;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
	error = gfs2_glock_nq_atime(&gh);
	if (error)
		return error;

	fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_di.di_flags);
	if (put_user(fsflags, ptr))
		error = -EFAULT;

	gfs2_glock_dq_m(1, &gh);
	gfs2_holder_uninit(&gh);
	return error;
}

void gfs2_set_inode_flags(struct inode *inode)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_dinode_host *di = &ip->i_di;
	unsigned int flags = inode->i_flags;

	flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
	if (di->di_flags & GFS2_DIF_IMMUTABLE)
		flags |= S_IMMUTABLE;
	if (di->di_flags & GFS2_DIF_APPENDONLY)
		flags |= S_APPEND;
	if (di->di_flags & GFS2_DIF_NOATIME)
		flags |= S_NOATIME;
	if (di->di_flags & GFS2_DIF_SYNC)
		flags |= S_SYNC;
	inode->i_flags = flags;
}

/* Flags that can be set by user space */
#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA|			\
			     GFS2_DIF_DIRECTIO|			\
			     GFS2_DIF_IMMUTABLE|		\
			     GFS2_DIF_APPENDONLY|		\
			     GFS2_DIF_NOATIME|			\
			     GFS2_DIF_SYNC|			\
			     GFS2_DIF_SYSTEM|			\
			     GFS2_DIF_INHERIT_DIRECTIO|		\
			     GFS2_DIF_INHERIT_JDATA)

/**
 * gfs2_set_flags - set flags on an inode
 * @inode: The inode
 * @flags: The flags to set
 * @mask: Indicates which flags are valid
 *
 */
static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct buffer_head *bh;
	struct gfs2_holder gh;
	int error;
	u32 new_flags, flags;

	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
	if (error)
		return error;

	flags = ip->i_di.di_flags;
	new_flags = (flags & ~mask) | (reqflags & mask);
	if ((new_flags ^ flags) == 0)
		goto out;

	if (S_ISDIR(inode->i_mode)) {
		if ((new_flags ^ flags) & GFS2_DIF_JDATA)
			new_flags ^= (GFS2_DIF_JDATA|GFS2_DIF_INHERIT_JDATA);
		if ((new_flags ^ flags) & GFS2_DIF_DIRECTIO)
			new_flags ^= (GFS2_DIF_DIRECTIO|GFS2_DIF_INHERIT_DIRECTIO);
	}

	error = -EINVAL;
	if ((new_flags ^ flags) & ~GFS2_FLAGS_USER_SET)
		goto out;

	error = -EPERM;
	if (IS_IMMUTABLE(inode) && (new_flags & GFS2_DIF_IMMUTABLE))
		goto out;
	if (IS_APPEND(inode) && (new_flags & GFS2_DIF_APPENDONLY))
		goto out;
	if (((new_flags ^ flags) & GFS2_DIF_IMMUTABLE) &&
	    !capable(CAP_LINUX_IMMUTABLE))
		goto out;
	if (!IS_IMMUTABLE(inode)) {
		error = permission(inode, MAY_WRITE, NULL);
		if (error)
			goto out;
	}

	error = gfs2_trans_begin(sdp, RES_DINODE, 0);
	if (error)
		goto out;
	error = gfs2_meta_inode_buffer(ip, &bh);
	if (error)
		goto out_trans_end;
	gfs2_trans_add_bh(ip->i_gl, bh, 1);
	ip->i_di.di_flags = new_flags;
	gfs2_dinode_out(ip, bh->b_data);
	brelse(bh);
	gfs2_set_inode_flags(inode);
out_trans_end:
	gfs2_trans_end(sdp);
out:
	gfs2_glock_dq_uninit(&gh);
	return error;
}

static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
{
	u32 fsflags, gfsflags;
	if (get_user(fsflags, ptr))
		return -EFAULT;
	gfsflags = fsflags_cvt(fsflags_to_gfs2, fsflags);
	return do_gfs2_set_flags(filp, gfsflags, ~0);
}

static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	switch(cmd) {
	case FS_IOC_GETFLAGS:
		return gfs2_get_flags(filp, (u32 __user *)arg);
	case FS_IOC_SETFLAGS:
		return gfs2_set_flags(filp, (u32 __user *)arg);
	}
	return -ENOTTY;
}


/**
 * gfs2_mmap -
 * @file: The file to map
 * @vma: The VMA which described the mapping
 *
 * Returns: 0 or error code
 */

static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_holder i_gh;
	int error;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
	error = gfs2_glock_nq_atime(&i_gh);
	if (error) {
		gfs2_holder_uninit(&i_gh);
		return error;
	}

	/* This is VM_MAYWRITE instead of VM_WRITE because a call
	   to mprotect() can turn on VM_WRITE later. */

	if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
	    (VM_MAYSHARE | VM_MAYWRITE))
		vma->vm_ops = &gfs2_vm_ops_sharewrite;
	else
		vma->vm_ops = &gfs2_vm_ops_private;

	gfs2_glock_dq_uninit(&i_gh);

	return error;
}

/**
 * gfs2_open - open a file
 * @inode: the inode to open
 * @file: the struct file for this opening
 *
 * Returns: errno
 */

static int gfs2_open(struct inode *inode, struct file *file)
{
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder i_gh;
	struct gfs2_file *fp;
	int error;

	fp = kzalloc(sizeof(struct gfs2_file), GFP_KERNEL);
	if (!fp)
		return -ENOMEM;

	mutex_init(&fp->f_fl_mutex);

	gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
	file->private_data = fp;

	if (S_ISREG(ip->i_inode.i_mode)) {
		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
					   &i_gh);
		if (error)
			goto fail;

		if (!(file->f_flags & O_LARGEFILE) &&
		    ip->i_di.di_size > MAX_NON_LFS) {
			error = -EFBIG;
			goto fail_gunlock;
		}

		/* Listen to the Direct I/O flag */

		if (ip->i_di.di_flags & GFS2_DIF_DIRECTIO)
			file->f_flags |= O_DIRECT;

		gfs2_glock_dq_uninit(&i_gh);
	}

	return 0;

fail_gunlock:
	gfs2_glock_dq_uninit(&i_gh);
fail:
	file->private_data = NULL;
	kfree(fp);
	return error;
}

/**
 * gfs2_close - called to close a struct file
 * @inode: the inode the struct file belongs to
 * @file: the struct file being closed
 *
 * Returns: errno
 */

static int gfs2_close(struct inode *inode, struct file *file)
{
	struct gfs2_sbd *sdp = inode->i_sb->s_fs_info;
	struct gfs2_file *fp;

	fp = file->private_data;
	file->private_data = NULL;

	if (gfs2_assert_warn(sdp, fp))
		return -EIO;

	kfree(fp);

	return 0;
}

/**
 * gfs2_fsync - sync the dirty data for a file (across the cluster)
 * @file: the file that points to the dentry (we ignore this)
 * @dentry: the dentry that points to the inode to sync
 *
 * The VFS will flush "normal" data for us. We only need to worry
 * about metadata here. For journaled data, we just do a log flush
 * as we can't avoid it. Otherwise we can just bale out if datasync
 * is set. For stuffed inodes we must flush the log in order to
 * ensure that all data is on disk.
 *
 * The call to write_inode_now() is there to write back metadata and
 * the inode itself. It does also try and write the data, but thats
 * (hopefully) a no-op due to the VFS having already called filemap_fdatawrite()
 * for us.
 *
 * Returns: errno
 */

static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
{
	struct inode *inode = dentry->d_inode;
	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
	int ret = 0;

	if (gfs2_is_jdata(GFS2_I(inode))) {
		gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
		return 0;
	}

	if (sync_state != 0) {
		if (!datasync)
			ret = write_inode_now(inode, 0);

		if (gfs2_is_stuffed(GFS2_I(inode)))
			gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
	}

	return ret;
}

/**
 * gfs2_lock - acquire/release a posix lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
	struct lm_lockname name =
		{ .ln_number = ip->i_num.no_addr,
		  .ln_type = LM_TYPE_PLOCK };

	if (!(fl->fl_flags & FL_POSIX))
		return -ENOLCK;
	if ((ip->i_inode.i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
		return -ENOLCK;

	if (sdp->sd_args.ar_localflocks) {
		if (IS_GETLK(cmd)) {
			struct file_lock tmp;
			int ret;
			ret = posix_test_lock(file, fl, &tmp);
			fl->fl_type = F_UNLCK;
			if (ret)
				memcpy(fl, &tmp, sizeof(struct file_lock));
			return 0;
		} else {
			return posix_lock_file_wait(file, fl);
		}
	}

	if (IS_GETLK(cmd))
		return gfs2_lm_plock_get(sdp, &name, file, fl);
	else if (fl->fl_type == F_UNLCK)
		return gfs2_lm_punlock(sdp, &name, file, fl);
	else
		return gfs2_lm_plock(sdp, &name, file, cmd, fl);
}

static int do_flock(struct file *file, int cmd, struct file_lock *fl)
{
	struct gfs2_file *fp = file->private_data;
	struct gfs2_holder *fl_gh = &fp->f_fl_gh;
	struct gfs2_inode *ip = GFS2_I(file->f_path.dentry->d_inode);
	struct gfs2_glock *gl;
	unsigned int state;
	int flags;
	int error = 0;

	state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
	flags = (IS_SETLKW(cmd) ? 0 : LM_FLAG_TRY) | GL_EXACT | GL_NOCACHE;

	mutex_lock(&fp->f_fl_mutex);

	gl = fl_gh->gh_gl;
	if (gl) {
		if (fl_gh->gh_state == state)
			goto out;
		gfs2_glock_hold(gl);
		flock_lock_file_wait(file,
				     &(struct file_lock){.fl_type = F_UNLCK});
		gfs2_glock_dq_uninit(fl_gh);
	} else {
		error = gfs2_glock_get(GFS2_SB(&ip->i_inode),
				      ip->i_num.no_addr, &gfs2_flock_glops,
				      CREATE, &gl);
		if (error)
			goto out;
	}

	gfs2_holder_init(gl, state, flags, fl_gh);
	gfs2_glock_put(gl);

	error = gfs2_glock_nq(fl_gh);
	if (error) {
		gfs2_holder_uninit(fl_gh);
		if (error == GLR_TRYFAILED)
			error = -EAGAIN;
	} else {
		error = flock_lock_file_wait(file, fl);
		gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
	}

out:
	mutex_unlock(&fp->f_fl_mutex);
	return error;
}

static void do_unflock(struct file *file, struct file_lock *fl)
{
	struct gfs2_file *fp = file->private_data;
	struct gfs2_holder *fl_gh = &fp->f_fl_gh;

	mutex_lock(&fp->f_fl_mutex);
	flock_lock_file_wait(file, fl);
	if (fl_gh->gh_gl)
		gfs2_glock_dq_uninit(fl_gh);
	mutex_unlock(&fp->f_fl_mutex);
}

/**
 * gfs2_flock - acquire/release a flock lock on a file
 * @file: the file pointer
 * @cmd: either modify or retrieve lock state, possibly wait
 * @fl: type and range of lock
 *
 * Returns: errno
 */

static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);

	if (!(fl->fl_flags & FL_FLOCK))
		return -ENOLCK;
	if ((ip->i_inode.i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
		return -ENOLCK;

	if (sdp->sd_args.ar_localflocks)
		return flock_lock_file_wait(file, fl);

	if (fl->fl_type == F_UNLCK) {
		do_unflock(file, fl);
		return 0;
	} else {
		return do_flock(file, cmd, fl);
	}
}

const struct file_operations gfs2_file_fops = {
	.llseek		= gfs2_llseek,
	.read		= do_sync_read,
	.aio_read	= generic_file_aio_read,
	.write		= do_sync_write,
	.aio_write	= generic_file_aio_write,
	.unlocked_ioctl	= gfs2_ioctl,
	.mmap		= gfs2_mmap,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.sendfile	= generic_file_sendfile,
	.flock		= gfs2_flock,
	.splice_read	= generic_file_splice_read,
	.splice_write	= generic_file_splice_write,
};

const struct file_operations gfs2_dir_fops = {
	.readdir	= gfs2_readdir,
	.unlocked_ioctl	= gfs2_ioctl,
	.open		= gfs2_open,
	.release	= gfs2_close,
	.fsync		= gfs2_fsync,
	.lock		= gfs2_lock,
	.flock		= gfs2_flock,
};