geom_vfs.c revision 137184 
1/*-
2 * Copyright (c) 2004 Poul-Henning Kamp
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 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/geom/geom_vfs.c 137184 2004-11-04 07:17:08Z phk $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bio.h>
33#include <sys/kernel.h>
34#include <sys/malloc.h>
35#include <sys/vnode.h>
36
37#include <geom/geom.h>
38#include <geom/geom_vfs.h>
39
40/*
41 * subroutines for use by filesystems.
42 *
43 * XXX: should maybe live somewhere else ?
44 */
45#include <sys/buf.h>
46
47static struct buf_ops __g_vfs_bufops = {
48	.bop_name =	"GEOM_VFS",
49	.bop_write =	bufwrite,
50	.bop_strategy =	g_vfs_strategy,
51};
52
53struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
54
55static struct g_class g_vfs_class = {
56	.name =		"VFS",
57	.version =	G_VERSION,
58	.orphan =	g_vfs_orphan,
59};
60
61DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
62
63static void
64g_vfs_done(struct bio *bip)
65{
66	struct buf *bp;
67
68	if (bip->bio_error) {
69		printf("g_vfs_done():");
70		g_print_bio(bip);
71		printf("error = %d\n", bip->bio_error);
72	}
73	bp = bip->bio_caller2;
74	bp->b_error = bip->bio_error;
75	bp->b_ioflags = bip->bio_flags;
76	if (bip->bio_error)
77		bp->b_ioflags |= BIO_ERROR;
78	bp->b_resid = bp->b_bcount - bip->bio_completed;
79	g_destroy_bio(bip);
80	mtx_lock(&Giant);
81	bufdone(bp);
82	mtx_unlock(&Giant);
83}
84
85void
86g_vfs_strategy(struct bufobj *bo, struct buf *bp)
87{
88	struct g_consumer *cp;
89	struct bio *bip;
90
91	cp = bo->bo_private;
92	G_VALID_CONSUMER(cp);
93
94	bip = g_alloc_bio();
95	bip->bio_cmd = bp->b_iocmd;
96	bip->bio_offset = bp->b_iooffset;
97	bip->bio_data = bp->b_data;
98	bip->bio_done = g_vfs_done;
99	bip->bio_caller2 = bp;
100	bip->bio_length = bp->b_bcount;
101	g_io_request(bip, cp);
102}
103
104void
105g_vfs_orphan(struct g_consumer *cp)
106{
107
108	/*
109	 * Don't do anything here yet.
110	 *
111	 * Ideally we should detach the consumer already now, but that
112	 * leads to a locking requirement in the I/O path to see if we have
113	 * a consumer or not.  Considering how ugly things are going to get
114	 * anyway as none of our filesystems are graceful about i/o errors,
115	 * this is not important right now.
116	 *
117	 * Down the road, this is the place where we could give the user
118	 * a "Abort, Retry or Ignore" option to replace the media again.
119	 */
120}
121
122int
123g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
124{
125	struct g_geom *gp;
126	struct g_provider *pp;
127	struct g_consumer *cp;
128	struct bufobj *bo;
129	int error;
130
131	g_topology_assert();
132
133	*cpp = NULL;
134	pp = g_dev_getprovider(vp->v_rdev);
135	if (pp == NULL)
136		return (ENOENT);
137	gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
138	cp = g_new_consumer(gp);
139	g_attach(cp, pp);
140	error = g_access(cp, 1, wr, 1);
141	if (error) {
142		g_wither_geom(gp, ENXIO);
143		return (error);
144	}
145	*cpp = cp;
146	bo = &vp->v_bufobj;
147	bo->bo_ops = g_vfs_bufops;
148	bo->bo_private = cp;
149	bo->bo_bsize = pp->sectorsize;
150
151	return (error);
152}
153