xref: /freebsd/sys/geom/geom_vfs.c (revision 1670a1c2a47d10ecccd001970b859caf93cd3b6e)
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 #include <sys/mount.h>	/* XXX Temporary for VFS_LOCK_GIANT */
37 
38 #include <geom/geom.h>
39 #include <geom/geom_vfs.h>
40 
41 /*
42  * subroutines for use by filesystems.
43  *
44  * XXX: should maybe live somewhere else ?
45  */
46 #include <sys/buf.h>
47 
48 static struct buf_ops __g_vfs_bufops = {
49 	.bop_name =	"GEOM_VFS",
50 	.bop_write =	bufwrite,
51 	.bop_strategy =	g_vfs_strategy,
52 	.bop_sync =	bufsync,
53 	.bop_bdflush =	bufbdflush
54 };
55 
56 struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
57 
58 static g_orphan_t g_vfs_orphan;
59 
60 static struct g_class g_vfs_class = {
61 	.name =		"VFS",
62 	.version =	G_VERSION,
63 	.orphan =	g_vfs_orphan,
64 };
65 
66 DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
67 
68 static void
69 g_vfs_done(struct bio *bip)
70 {
71 	struct buf *bp;
72 	int vfslocked;
73 
74 	/*
75 	 * Provider ('bio_to') could have withered away sometime
76 	 * between incrementing the 'nend' in g_io_deliver() and now,
77 	 * making 'bio_to' a dangling pointer.  We cannot do that
78 	 * in g_wither_geom(), as it would require going over
79 	 * the 'g_bio_run_up' list, resetting the pointer.
80 	 */
81 	if (bip->bio_from->provider == NULL)
82 		bip->bio_to = NULL;
83 
84 	if (bip->bio_error) {
85 		printf("g_vfs_done():");
86 		g_print_bio(bip);
87 		printf("error = %d\n", bip->bio_error);
88 	}
89 	bp = bip->bio_caller2;
90 	bp->b_error = bip->bio_error;
91 	bp->b_ioflags = bip->bio_flags;
92 	if (bip->bio_error)
93 		bp->b_ioflags |= BIO_ERROR;
94 	bp->b_resid = bp->b_bcount - bip->bio_completed;
95 	g_destroy_bio(bip);
96 	vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
97 	bufdone(bp);
98 	VFS_UNLOCK_GIANT(vfslocked);
99 }
100 
101 void
102 g_vfs_strategy(struct bufobj *bo, struct buf *bp)
103 {
104 	struct g_consumer *cp;
105 	struct bio *bip;
106 	int vfslocked;
107 
108 	cp = bo->bo_private;
109 	/* G_VALID_CONSUMER(cp); We likely lack topology lock */
110 
111 	/*
112 	 * If the the provider has orphaned us, just return EXIO.
113 	 */
114 	if (cp->provider == NULL) {
115 		bp->b_error = ENXIO;
116 		bp->b_ioflags |= BIO_ERROR;
117 		vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
118 		bufdone(bp);
119 		VFS_UNLOCK_GIANT(vfslocked);
120 		return;
121 	}
122 
123 	bip = g_alloc_bio();
124 	bip->bio_cmd = bp->b_iocmd;
125 	bip->bio_offset = bp->b_iooffset;
126 	bip->bio_data = bp->b_data;
127 	bip->bio_done = g_vfs_done;
128 	bip->bio_caller2 = bp;
129 	bip->bio_length = bp->b_bcount;
130 	g_io_request(bip, cp);
131 }
132 
133 static void
134 g_vfs_orphan(struct g_consumer *cp)
135 {
136 	struct g_geom *gp;
137 
138 	g_topology_assert();
139 
140 	gp = cp->geom;
141 	g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
142 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
143 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
144 	g_detach(cp);
145 
146 	/*
147 	 * Do not destroy the geom.  Filesystem will do that during unmount.
148 	 */
149 }
150 
151 int
152 g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
153 {
154 	struct g_geom *gp;
155 	struct g_provider *pp;
156 	struct g_consumer *cp;
157 	struct bufobj *bo;
158 	int vfslocked;
159 	int error;
160 
161 	g_topology_assert();
162 
163 	*cpp = NULL;
164 	bo = &vp->v_bufobj;
165 	if (bo->bo_private != vp)
166 		return (EBUSY);
167 
168 	pp = g_dev_getprovider(vp->v_rdev);
169 	if (pp == NULL)
170 		return (ENOENT);
171 	gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
172 	cp = g_new_consumer(gp);
173 	g_attach(cp, pp);
174 	error = g_access(cp, 1, wr, 1);
175 	if (error) {
176 		g_wither_geom(gp, ENXIO);
177 		return (error);
178 	}
179 	vfslocked = VFS_LOCK_GIANT(vp->v_mount);
180 	vnode_create_vobject(vp, pp->mediasize, curthread);
181 	VFS_UNLOCK_GIANT(vfslocked);
182 	*cpp = cp;
183 	cp->private = vp;
184 	bo->bo_ops = g_vfs_bufops;
185 	bo->bo_private = cp;
186 	bo->bo_bsize = pp->sectorsize;
187 	gp->softc = bo;
188 
189 	return (error);
190 }
191 
192 void
193 g_vfs_close(struct g_consumer *cp)
194 {
195 	struct g_geom *gp;
196 	struct bufobj *bo;
197 
198 	g_topology_assert();
199 
200 	gp = cp->geom;
201 	bo = gp->softc;
202 	bufobj_invalbuf(bo, V_SAVE, 0, 0);
203 	bo->bo_private = cp->private;
204 	g_wither_geom_close(gp, ENXIO);
205 }
206