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/10.0/sys/geom/geom_vfs.c 248508 2013-03-19 14:13:12Z kib $");
29
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bio.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/mutex.h>
37 #include <sys/vnode.h>
38 #include <sys/mount.h>
39
40 #include <geom/geom.h>
41 #include <geom/geom_vfs.h>
42
43 /*
44 * subroutines for use by filesystems.
45 *
46 * XXX: should maybe live somewhere else ?
47 */
48 #include <sys/buf.h>
49
50 struct g_vfs_softc {
51 struct mtx sc_mtx;
52 struct bufobj *sc_bo;
53 int sc_active;
54 int sc_orphaned;
55 };
56
57 static struct buf_ops __g_vfs_bufops = {
58 .bop_name = "GEOM_VFS",
59 .bop_write = bufwrite,
60 .bop_strategy = g_vfs_strategy,
61 .bop_sync = bufsync,
62 .bop_bdflush = bufbdflush
63 };
64
65 struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
66
67 static g_orphan_t g_vfs_orphan;
68
69 static struct g_class g_vfs_class = {
70 .name = "VFS",
71 .version = G_VERSION,
72 .orphan = g_vfs_orphan,
73 };
74
75 DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
76
77 static void
78 g_vfs_destroy(void *arg, int flags __unused)
79 {
80 struct g_consumer *cp;
81
82 g_topology_assert();
83 cp = arg;
84 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
85 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
86 g_detach(cp);
87 if (cp->geom->softc == NULL)
88 g_wither_geom(cp->geom, ENXIO);
89 }
90
91 static void
92 g_vfs_done(struct bio *bip)
93 {
94 struct g_consumer *cp;
95 struct g_vfs_softc *sc;
96 struct buf *bp;
97 int destroy;
98 struct mount *mp;
99 struct vnode *vp;
100 struct cdev *cdevp;
101
102 /*
103 * Collect statistics on synchronous and asynchronous read
104 * and write counts for disks that have associated filesystems.
105 * Since this run by the g_up thread it is single threaded and
106 * we do not need to use atomic increments on the counters.
107 */
108 bp = bip->bio_caller2;
109 vp = bp->b_vp;
110 if (vp == NULL) {
111 mp = NULL;
112 } else {
113 /*
114 * If not a disk vnode, use its associated mount point
115 * otherwise use the mountpoint associated with the disk.
116 */
117 VI_LOCK(vp);
118 if (vp->v_type != VCHR ||
119 (cdevp = vp->v_rdev) == NULL ||
120 cdevp->si_devsw == NULL ||
121 (cdevp->si_devsw->d_flags & D_DISK) == 0)
122 mp = vp->v_mount;
123 else
124 mp = cdevp->si_mountpt;
125 VI_UNLOCK(vp);
126 }
127 if (mp != NULL) {
128 if (bp->b_iocmd == BIO_WRITE) {
129 if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
130 mp->mnt_stat.f_asyncwrites++;
131 else
132 mp->mnt_stat.f_syncwrites++;
133 } else {
134 if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
135 mp->mnt_stat.f_asyncreads++;
136 else
137 mp->mnt_stat.f_syncreads++;
138 }
139 }
140
141 cp = bip->bio_from;
142 sc = cp->geom->softc;
143 if (bip->bio_error) {
144 printf("g_vfs_done():");
145 g_print_bio(bip);
146 printf("error = %d\n", bip->bio_error);
147 }
148 bp->b_error = bip->bio_error;
149 bp->b_ioflags = bip->bio_flags;
150 if (bip->bio_error)
151 bp->b_ioflags |= BIO_ERROR;
152 bp->b_resid = bp->b_bcount - bip->bio_completed;
153 g_destroy_bio(bip);
154
155 mtx_lock(&sc->sc_mtx);
156 destroy = ((--sc->sc_active) == 0 && sc->sc_orphaned);
157 mtx_unlock(&sc->sc_mtx);
158 if (destroy)
159 g_post_event(g_vfs_destroy, cp, M_WAITOK, NULL);
160
161 bufdone(bp);
162 }
163
164 void
165 g_vfs_strategy(struct bufobj *bo, struct buf *bp)
166 {
167 struct g_vfs_softc *sc;
168 struct g_consumer *cp;
169 struct bio *bip;
170
171 cp = bo->bo_private;
172 sc = cp->geom->softc;
173
174 /*
175 * If the provider has orphaned us, just return EXIO.
176 */
177 mtx_lock(&sc->sc_mtx);
178 if (sc->sc_orphaned) {
179 mtx_unlock(&sc->sc_mtx);
180 bp->b_error = ENXIO;
181 bp->b_ioflags |= BIO_ERROR;
182 bufdone(bp);
183 return;
184 }
185 sc->sc_active++;
186 mtx_unlock(&sc->sc_mtx);
187
188 bip = g_alloc_bio();
189 bip->bio_cmd = bp->b_iocmd;
190 bip->bio_offset = bp->b_iooffset;
191 bip->bio_length = bp->b_bcount;
192 bdata2bio(bp, bip);
193 if ((bp->b_flags & B_BARRIER) != 0) {
194 bip->bio_flags |= BIO_ORDERED;
195 bp->b_flags &= ~B_BARRIER;
196 }
197 bip->bio_done = g_vfs_done;
198 bip->bio_caller2 = bp;
199 g_io_request(bip, cp);
200 }
201
202 static void
203 g_vfs_orphan(struct g_consumer *cp)
204 {
205 struct g_geom *gp;
206 struct g_vfs_softc *sc;
207 int destroy;
208
209 g_topology_assert();
210
211 gp = cp->geom;
212 g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
213 sc = gp->softc;
214 if (sc == NULL)
215 return;
216 mtx_lock(&sc->sc_mtx);
217 sc->sc_orphaned = 1;
218 destroy = (sc->sc_active == 0);
219 mtx_unlock(&sc->sc_mtx);
220 if (destroy)
221 g_vfs_destroy(cp, 0);
222
223 /*
224 * Do not destroy the geom. Filesystem will do that during unmount.
225 */
226 }
227
228 int
229 g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
230 {
231 struct g_geom *gp;
232 struct g_provider *pp;
233 struct g_consumer *cp;
234 struct g_vfs_softc *sc;
235 struct bufobj *bo;
236 int error;
237
238 g_topology_assert();
239
240 *cpp = NULL;
241 bo = &vp->v_bufobj;
242 if (bo->bo_private != vp)
243 return (EBUSY);
244
245 pp = g_dev_getprovider(vp->v_rdev);
246 if (pp == NULL)
247 return (ENOENT);
248 gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
249 sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
250 mtx_init(&sc->sc_mtx, "g_vfs", NULL, MTX_DEF);
251 sc->sc_bo = bo;
252 gp->softc = sc;
253 cp = g_new_consumer(gp);
254 g_attach(cp, pp);
255 error = g_access(cp, 1, wr, wr);
256 if (error) {
257 g_wither_geom(gp, ENXIO);
258 return (error);
259 }
260 vnode_create_vobject(vp, pp->mediasize, curthread);
261 *cpp = cp;
262 cp->private = vp;
263 bo->bo_ops = g_vfs_bufops;
264 bo->bo_private = cp;
265 bo->bo_bsize = pp->sectorsize;
266
267 return (error);
268 }
269
270 void
271 g_vfs_close(struct g_consumer *cp)
272 {
273 struct g_geom *gp;
274 struct g_vfs_softc *sc;
275
276 g_topology_assert();
277
278 gp = cp->geom;
279 sc = gp->softc;
280 bufobj_invalbuf(sc->sc_bo, V_SAVE, 0, 0);
281 sc->sc_bo->bo_private = cp->private;
282 gp->softc = NULL;
283 mtx_destroy(&sc->sc_mtx);
284 if (!sc->sc_orphaned || cp->provider == NULL)
285 g_wither_geom_close(gp, ENXIO);
286 g_free(sc);
287 }
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