summaryrefslogtreecommitdiffstats
path: root/fs/xfs/linux-2.6/xfs_vnode.c
blob: 849c61c74f3cfbb19a4b29696380ec33b27dce3d (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
/*
 * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include "xfs.h"


uint64_t vn_generation;		/* vnode generation number */
DEFINE_SPINLOCK(vnumber_lock);

/*
 * Dedicated vnode inactive/reclaim sync semaphores.
 * Prime number of hash buckets since address is used as the key.
 */
#define NVSYNC                  37
#define vptosync(v)             (&vsync[((unsigned long)v) % NVSYNC])
sv_t vsync[NVSYNC];

/*
 * Translate stat(2) file types to vnode types and vice versa.
 * Aware of numeric order of S_IFMT and vnode type values.
 */
enum vtype iftovt_tab[] = {
	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VNON
};

u_short vttoif_tab[] = {
	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK, S_IFIFO, 0, S_IFSOCK
};


void
vn_init(void)
{
	register sv_t *svp;
	register int i;

	for (svp = vsync, i = 0; i < NVSYNC; i++, svp++)
		init_sv(svp, SV_DEFAULT, "vsy", i);
}

/*
 * Clean a vnode of filesystem-specific data and prepare it for reuse.
 */
STATIC int
vn_reclaim(
	struct vnode	*vp)
{
	int		error;

	XFS_STATS_INC(vn_reclaim);
	vn_trace_entry(vp, "vn_reclaim", (inst_t *)__return_address);

	/*
	 * Only make the VOP_RECLAIM call if there are behaviors
	 * to call.
	 */
	if (vp->v_fbhv) {
		VOP_RECLAIM(vp, error);
		if (error)
			return -error;
	}
	ASSERT(vp->v_fbhv == NULL);

	VN_LOCK(vp);
	vp->v_flag &= (VRECLM|VWAIT);
	VN_UNLOCK(vp, 0);

	vp->v_type = VNON;
	vp->v_fbhv = NULL;

#ifdef XFS_VNODE_TRACE
	ktrace_free(vp->v_trace);
	vp->v_trace = NULL;
#endif

	return 0;
}

STATIC void
vn_wakeup(
	struct vnode	*vp)
{
	VN_LOCK(vp);
	if (vp->v_flag & VWAIT)
		sv_broadcast(vptosync(vp));
	vp->v_flag &= ~(VRECLM|VWAIT|VMODIFIED);
	VN_UNLOCK(vp, 0);
}

int
vn_wait(
	struct vnode	*vp)
{
	VN_LOCK(vp);
	if (vp->v_flag & (VINACT | VRECLM)) {
		vp->v_flag |= VWAIT;
		sv_wait(vptosync(vp), PINOD, &vp->v_lock, 0);
		return 1;
	}
	VN_UNLOCK(vp, 0);
	return 0;
}

struct vnode *
vn_initialize(
	struct inode	*inode)
{
	struct vnode	*vp = LINVFS_GET_VP(inode);

	XFS_STATS_INC(vn_active);
	XFS_STATS_INC(vn_alloc);

	vp->v_flag = VMODIFIED;
	spinlock_init(&vp->v_lock, "v_lock");

	spin_lock(&vnumber_lock);
	if (!++vn_generation)	/* v_number shouldn't be zero */
		vn_generation++;
	vp->v_number = vn_generation;
	spin_unlock(&vnumber_lock);

	ASSERT(VN_CACHED(vp) == 0);

	/* Initialize the first behavior and the behavior chain head. */
	vn_bhv_head_init(VN_BHV_HEAD(vp), "vnode");

#ifdef	XFS_VNODE_TRACE
	vp->v_trace = ktrace_alloc(VNODE_TRACE_SIZE, KM_SLEEP);
	printk("Allocated VNODE_TRACE at 0x%p\n", vp->v_trace);
#endif	/* XFS_VNODE_TRACE */

	vn_trace_exit(vp, "vn_initialize", (inst_t *)__return_address);
	return vp;
}

/*
 * Get a reference on a vnode.
 */
vnode_t *
vn_get(
	struct vnode	*vp,
	vmap_t		*vmap)
{
	struct inode	*inode;

	XFS_STATS_INC(vn_get);
	inode = LINVFS_GET_IP(vp);
	if (inode->i_state & I_FREEING)
		return NULL;

	inode = ilookup(vmap->v_vfsp->vfs_super, vmap->v_ino);
	if (!inode)	/* Inode not present */
		return NULL;

	vn_trace_exit(vp, "vn_get", (inst_t *)__return_address);

	return vp;
}

/*
 * Revalidate the Linux inode from the vattr.
 * Note: i_size _not_ updated; we must hold the inode
 * semaphore when doing that - callers responsibility.
 */
void
vn_revalidate_core(
	struct vnode	*vp,
	vattr_t		*vap)
{
	struct inode	*inode = LINVFS_GET_IP(vp);

	inode->i_mode	    = VTTOIF(vap->va_type) | vap->va_mode;
	inode->i_nlink	    = vap->va_nlink;
	inode->i_uid	    = vap->va_uid;
	inode->i_gid	    = vap->va_gid;
	inode->i_blocks	    = vap->va_nblocks;
	inode->i_mtime	    = vap->va_mtime;
	inode->i_ctime	    = vap->va_ctime;
	inode->i_atime	    = vap->va_atime;
	if (vap->va_xflags & XFS_XFLAG_IMMUTABLE)
		inode->i_flags |= S_IMMUTABLE;
	else
		inode->i_flags &= ~S_IMMUTABLE;
	if (vap->va_xflags & XFS_XFLAG_APPEND)
		inode->i_flags |= S_APPEND;
	else
		inode->i_flags &= ~S_APPEND;
	if (vap->va_xflags & XFS_XFLAG_SYNC)
		inode->i_flags |= S_SYNC;
	else
		inode->i_flags &= ~S_SYNC;
	if (vap->va_xflags & XFS_XFLAG_NOATIME)
		inode->i_flags |= S_NOATIME;
	else
		inode->i_flags &= ~S_NOATIME;
}

/*
 * Revalidate the Linux inode from the vnode.
 */
int
vn_revalidate(
	struct vnode	*vp)
{
	vattr_t		va;
	int		error;

	vn_trace_entry(vp, "vn_revalidate", (inst_t *)__return_address);
	ASSERT(vp->v_fbhv != NULL);

	va.va_mask = XFS_AT_STAT|XFS_AT_XFLAGS;
	VOP_GETATTR(vp, &va, 0, NULL, error);
	if (!error) {
		vn_revalidate_core(vp, &va);
		VUNMODIFY(vp);
	}
	return -error;
}

/*
 * purge a vnode from the cache
 * At this point the vnode is guaranteed to have no references (vn_count == 0)
 * The caller has to make sure that there are no ways someone could
 * get a handle (via vn_get) on the vnode (usually done via a mount/vfs lock).
 */
void
vn_purge(
	struct vnode	*vp,
	vmap_t		*vmap)
{
	vn_trace_entry(vp, "vn_purge", (inst_t *)__return_address);

again:
	/*
	 * Check whether vp has already been reclaimed since our caller
	 * sampled its version while holding a filesystem cache lock that
	 * its VOP_RECLAIM function acquires.
	 */
	VN_LOCK(vp);
	if (vp->v_number != vmap->v_number) {
		VN_UNLOCK(vp, 0);
		return;
	}

	/*
	 * If vp is being reclaimed or inactivated, wait until it is inert,
	 * then proceed.  Can't assume that vnode is actually reclaimed
	 * just because the reclaimed flag is asserted -- a vn_alloc
	 * reclaim can fail.
	 */
	if (vp->v_flag & (VINACT | VRECLM)) {
		ASSERT(vn_count(vp) == 0);
		vp->v_flag |= VWAIT;
		sv_wait(vptosync(vp), PINOD, &vp->v_lock, 0);
		goto again;
	}

	/*
	 * Another process could have raced in and gotten this vnode...
	 */
	if (vn_count(vp) > 0) {
		VN_UNLOCK(vp, 0);
		return;
	}

	XFS_STATS_DEC(vn_active);
	vp->v_flag |= VRECLM;
	VN_UNLOCK(vp, 0);

	/*
	 * Call VOP_RECLAIM and clean vp. The FSYNC_INVAL flag tells
	 * vp's filesystem to flush and invalidate all cached resources.
	 * When vn_reclaim returns, vp should have no private data,
	 * either in a system cache or attached to v_data.
	 */
	if (vn_reclaim(vp) != 0)
		panic("vn_purge: cannot reclaim");

	/*
	 * Wakeup anyone waiting for vp to be reclaimed.
	 */
	vn_wakeup(vp);
}

/*
 * Add a reference to a referenced vnode.
 */
struct vnode *
vn_hold(
	struct vnode	*vp)
{
	struct inode	*inode;

	XFS_STATS_INC(vn_hold);

	VN_LOCK(vp);
	inode = igrab(LINVFS_GET_IP(vp));
	ASSERT(inode);
	VN_UNLOCK(vp, 0);

	return vp;
}

/*
 *  Call VOP_INACTIVE on last reference.
 */
void
vn_rele(
	struct vnode	*vp)
{
	int		vcnt;
	int		cache;

	XFS_STATS_INC(vn_rele);

	VN_LOCK(vp);

	vn_trace_entry(vp, "vn_rele", (inst_t *)__return_address);
	vcnt = vn_count(vp);

	/*
	 * Since we always get called from put_inode we know
	 * that i_count won't be decremented after we
	 * return.
	 */
	if (!vcnt) {
		/*
		 * As soon as we turn this on, noone can find us in vn_get
		 * until we turn off VINACT or VRECLM
		 */
		vp->v_flag |= VINACT;
		VN_UNLOCK(vp, 0);

		/*
		 * Do not make the VOP_INACTIVE call if there
		 * are no behaviors attached to the vnode to call.
		 */
		if (vp->v_fbhv)
			VOP_INACTIVE(vp, NULL, cache);

		VN_LOCK(vp);
		if (vp->v_flag & VWAIT)
			sv_broadcast(vptosync(vp));

		vp->v_flag &= ~(VINACT|VWAIT|VRECLM|VMODIFIED);
	}

	VN_UNLOCK(vp, 0);

	vn_trace_exit(vp, "vn_rele", (inst_t *)__return_address);
}

/*
 * Finish the removal of a vnode.
 */
void
vn_remove(
	struct vnode	*vp)
{
	vmap_t		vmap;

	/* Make sure we don't do this to the same vnode twice */
	if (!(vp->v_fbhv))
		return;

	XFS_STATS_INC(vn_remove);
	vn_trace_exit(vp, "vn_remove", (inst_t *)__return_address);

	/*
	 * After the following purge the vnode
	 * will no longer exist.
	 */
	VMAP(vp, vmap);
	vn_purge(vp, &vmap);
}


#ifdef	XFS_VNODE_TRACE

#define KTRACE_ENTER(vp, vk, s, line, ra)			\
	ktrace_enter(	(vp)->v_trace,				\
/*  0 */		(void *)(__psint_t)(vk),		\
/*  1 */		(void *)(s),				\
/*  2 */		(void *)(__psint_t) line,		\
/*  3 */		(void *)(vn_count(vp)), \
/*  4 */		(void *)(ra),				\
/*  5 */		(void *)(__psunsigned_t)(vp)->v_flag,	\
/*  6 */		(void *)(__psint_t)current_cpu(),	\
/*  7 */		(void *)(__psint_t)current_pid(),	\
/*  8 */		(void *)__return_address,		\
/*  9 */		0, 0, 0, 0, 0, 0, 0)

/*
 * Vnode tracing code.
 */
void
vn_trace_entry(vnode_t *vp, char *func, inst_t *ra)
{
	KTRACE_ENTER(vp, VNODE_KTRACE_ENTRY, func, 0, ra);
}

void
vn_trace_exit(vnode_t *vp, char *func, inst_t *ra)
{
	KTRACE_ENTER(vp, VNODE_KTRACE_EXIT, func, 0, ra);
}

void
vn_trace_hold(vnode_t *vp, char *file, int line, inst_t *ra)
{
	KTRACE_ENTER(vp, VNODE_KTRACE_HOLD, file, line, ra);
}

void
vn_trace_ref(vnode_t *vp, char *file, int line, inst_t *ra)
{
	KTRACE_ENTER(vp, VNODE_KTRACE_REF, file, line, ra);
}

void
vn_trace_rele(vnode_t *vp, char *file, int line, inst_t *ra)
{
	KTRACE_ENTER(vp, VNODE_KTRACE_RELE, file, line, ra);
}
#endif	/* XFS_VNODE_TRACE */