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: stable/9/sys/geom/geom_vfs.c 251897 2013-06-18 05:21:40Z scottl $");
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> /* XXX Temporary for VFS_LOCK_GIANT */
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
g_vfs_destroy(void * arg,int flags __unused)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
g_vfs_done(struct bio * bip)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 vfslocked, destroy;
98 struct mount *mp;
99 struct vnode *vp;
100 struct cdev *cdevp;
101
102 cp = bip->bio_from;
103 sc = cp->geom->softc;
104 /*
105 * Collect statistics on synchronous and asynchronous read
106 * and write counts for disks that have associated filesystems.
107 * Since this is run by the g_up thread it is single threaded and
108 * we do not need to use atomic increments on the counters.
109 */
110 bp = bip->bio_caller2;
111 vp = bp->b_vp;
112 if (vp == NULL) {
113 mp = NULL;
114 } else {
115 /*
116 * If not a disk vnode, use its associated mount point
117 * otherwise use the mountpoint associated with the disk.
118 */
119 VI_LOCK(vp);
120 if (vp->v_type != VCHR ||
121 (cdevp = vp->v_rdev) == NULL ||
122 cdevp->si_devsw == NULL ||
123 (cdevp->si_devsw->d_flags & D_DISK) == 0)
124 mp = vp->v_mount;
125 else
126 mp = cdevp->si_mountpt;
127 VI_UNLOCK(vp);
128 }
129 if (mp != NULL) {
130 if (bp->b_iocmd == BIO_WRITE) {
131 if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
132 mp->mnt_stat.f_asyncwrites++;
133 else
134 mp->mnt_stat.f_syncwrites++;
135 } else {
136 if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
137 mp->mnt_stat.f_asyncreads++;
138 else
139 mp->mnt_stat.f_syncreads++;
140 }
141 }
142
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 vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
162 bufdone(bp);
163 VFS_UNLOCK_GIANT(vfslocked);
164 }
165
166 void
g_vfs_strategy(struct bufobj * bo,struct buf * bp)167 g_vfs_strategy(struct bufobj *bo, struct buf *bp)
168 {
169 struct g_vfs_softc *sc;
170 struct g_consumer *cp;
171 struct bio *bip;
172 int vfslocked;
173
174 cp = bo->bo_private;
175 sc = cp->geom->softc;
176
177 /*
178 * If the provider has orphaned us, just return EXIO.
179 */
180 mtx_lock(&sc->sc_mtx);
181 if (sc->sc_orphaned) {
182 mtx_unlock(&sc->sc_mtx);
183 bp->b_error = ENXIO;
184 bp->b_ioflags |= BIO_ERROR;
185 vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
186 bufdone(bp);
187 VFS_UNLOCK_GIANT(vfslocked);
188 return;
189 }
190 sc->sc_active++;
191 mtx_unlock(&sc->sc_mtx);
192
193 bip = g_alloc_bio();
194 bip->bio_cmd = bp->b_iocmd;
195 bip->bio_offset = bp->b_iooffset;
196 bip->bio_length = bp->b_bcount;
197 bdata2bio(bp, bip);
198 if ((bp->b_flags & B_BARRIER) != 0) {
199 bip->bio_flags |= BIO_ORDERED;
200 bp->b_flags &= ~B_BARRIER;
201 }
202 bip->bio_done = g_vfs_done;
203 bip->bio_caller2 = bp;
204 g_io_request(bip, cp);
205 }
206
207 static void
g_vfs_orphan(struct g_consumer * cp)208 g_vfs_orphan(struct g_consumer *cp)
209 {
210 struct g_geom *gp;
211 struct g_vfs_softc *sc;
212 int destroy;
213
214 g_topology_assert();
215
216 gp = cp->geom;
217 g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
218 sc = gp->softc;
219 if (sc == NULL)
220 return;
221 mtx_lock(&sc->sc_mtx);
222 sc->sc_orphaned = 1;
223 destroy = (sc->sc_active == 0);
224 mtx_unlock(&sc->sc_mtx);
225 if (destroy)
226 g_vfs_destroy(cp, 0);
227
228 /*
229 * Do not destroy the geom. Filesystem will do that during unmount.
230 */
231 }
232
233 int
g_vfs_open(struct vnode * vp,struct g_consumer ** cpp,const char * fsname,int wr)234 g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
235 {
236 struct g_geom *gp;
237 struct g_provider *pp;
238 struct g_consumer *cp;
239 struct g_vfs_softc *sc;
240 struct bufobj *bo;
241 int vfslocked;
242 int error;
243
244 g_topology_assert();
245
246 *cpp = NULL;
247 bo = &vp->v_bufobj;
248 if (bo->bo_private != vp)
249 return (EBUSY);
250
251 pp = g_dev_getprovider(vp->v_rdev);
252 if (pp == NULL)
253 return (ENOENT);
254 gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
255 sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
256 mtx_init(&sc->sc_mtx, "g_vfs", NULL, MTX_DEF);
257 sc->sc_bo = bo;
258 gp->softc = sc;
259 cp = g_new_consumer(gp);
260 g_attach(cp, pp);
261 error = g_access(cp, 1, wr, wr);
262 if (error) {
263 g_wither_geom(gp, ENXIO);
264 return (error);
265 }
266 vfslocked = VFS_LOCK_GIANT(vp->v_mount);
267 vnode_create_vobject(vp, pp->mediasize, curthread);
268 VFS_UNLOCK_GIANT(vfslocked);
269 *cpp = cp;
270 cp->private = vp;
271 bo->bo_ops = g_vfs_bufops;
272 bo->bo_private = cp;
273 bo->bo_bsize = pp->sectorsize;
274
275 return (error);
276 }
277
278 void
g_vfs_close(struct g_consumer * cp)279 g_vfs_close(struct g_consumer *cp)
280 {
281 struct g_geom *gp;
282 struct g_vfs_softc *sc;
283
284 g_topology_assert();
285
286 gp = cp->geom;
287 sc = gp->softc;
288 bufobj_invalbuf(sc->sc_bo, V_SAVE, 0, 0);
289 sc->sc_bo->bo_private = cp->private;
290 gp->softc = NULL;
291 mtx_destroy(&sc->sc_mtx);
292 if (!sc->sc_orphaned || cp->provider == NULL)
293 g_wither_geom_close(gp, ENXIO);
294 g_free(sc);
295 }
296