FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_vfs.c
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: releng/9.0/sys/geom/geom_vfs.c 223900 2011-07-10 00:41:31Z mckusick $");
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 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, wr);
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 }
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