xref: /freebsd/sys/geom/geom_vfs.c (revision 6e0da4f753ed6b5d26395001a6194b4fdea70177)
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("$FreeBSD$");
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 
47 static struct buf_ops __g_vfs_bufops = {
48 	.bop_name =	"GEOM_VFS",
49 	.bop_write =	bufwrite,
50 	.bop_strategy =	g_vfs_strategy,
51 	.bop_sync =	bufsync,
52 };
53 
54 struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
55 
56 static struct g_class g_vfs_class = {
57 	.name =		"VFS",
58 	.version =	G_VERSION,
59 	.orphan =	g_vfs_orphan,
60 };
61 
62 DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
63 
64 static void
65 g_vfs_done(struct bio *bip)
66 {
67 	struct buf *bp;
68 
69 	if (bip->bio_error) {
70 		printf("g_vfs_done():");
71 		g_print_bio(bip);
72 		printf("error = %d\n", bip->bio_error);
73 	}
74 	bp = bip->bio_caller2;
75 	bp->b_error = bip->bio_error;
76 	bp->b_ioflags = bip->bio_flags;
77 	if (bip->bio_error)
78 		bp->b_ioflags |= BIO_ERROR;
79 	bp->b_resid = bp->b_bcount - bip->bio_completed;
80 	g_destroy_bio(bip);
81 	mtx_lock(&Giant);
82 	bufdone(bp);
83 	mtx_unlock(&Giant);
84 }
85 
86 void
87 g_vfs_strategy(struct bufobj *bo, struct buf *bp)
88 {
89 	struct g_consumer *cp;
90 	struct bio *bip;
91 
92 	cp = bo->bo_private;
93 	G_VALID_CONSUMER(cp);
94 
95 	bip = g_alloc_bio();
96 	bip->bio_cmd = bp->b_iocmd;
97 	bip->bio_offset = bp->b_iooffset;
98 	bip->bio_data = bp->b_data;
99 	bip->bio_done = g_vfs_done;
100 	bip->bio_caller2 = bp;
101 	bip->bio_length = bp->b_bcount;
102 	g_io_request(bip, cp);
103 }
104 
105 void
106 g_vfs_orphan(struct g_consumer *cp)
107 {
108 
109 	/*
110 	 * Don't do anything here yet.
111 	 *
112 	 * Ideally we should detach the consumer already now, but that
113 	 * leads to a locking requirement in the I/O path to see if we have
114 	 * a consumer or not.  Considering how ugly things are going to get
115 	 * anyway as none of our filesystems are graceful about i/o errors,
116 	 * this is not important right now.
117 	 *
118 	 * Down the road, this is the place where we could give the user
119 	 * a "Abort, Retry or Ignore" option to replace the media again.
120 	 */
121 }
122 
123 int
124 g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
125 {
126 	struct g_geom *gp;
127 	struct g_provider *pp;
128 	struct g_consumer *cp;
129 	struct bufobj *bo;
130 	int error;
131 
132 	g_topology_assert();
133 
134 	*cpp = NULL;
135 	pp = g_dev_getprovider(vp->v_rdev);
136 	if (pp == NULL)
137 		return (ENOENT);
138 	gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
139 	cp = g_new_consumer(gp);
140 	g_attach(cp, pp);
141 	error = g_access(cp, 1, wr, 1);
142 	if (error) {
143 		g_wither_geom(gp, ENXIO);
144 		return (error);
145 	}
146 	*cpp = cp;
147 	bo = &vp->v_bufobj;
148 	bo->bo_ops = g_vfs_bufops;
149 	bo->bo_private = cp;
150 	bo->bo_bsize = pp->sectorsize;
151 
152 	return (error);
153 }
154