freebsd-dev/sys/geom/geom_vfs.c
Alexander Motin 3631c6382f Implement media change notification for DA and CD removable media devices.
It includes three parts:
 1) Modifications to CAM to detect media media changes and report them to
disk(9) layer. For modern SATA (and potentially UAS) devices it utilizes
Asynchronous Notification mechanism to receive events from hardware.
Active polling with TEST UNIT READY commands with 3 seconds period is used
for incapable hardware. After that both CD and DA drivers work the same way,
detecting two conditions: "NOT READY: Medium not present" after medium was
detected previously, and "UNIT ATTENTION: Not ready to ready change, medium
may have changed". First one reported to disk(9) as media removal, second
as media insert/change. To reliably receive second event new
AC_UNIT_ATTENTION async added to make UAs broadcasted to all periphs by
generic error handling code in cam_periph_error().
 2) Modifications to GEOM core to handle media remove and change events.
Media removal handled by spoiling all consumers attached to the provider.
Media change event also schedules provider retaste after spoiling to probe
new media. New flag G_CF_ORPHAN was added to consumers to reflect that
consumer is in process of destruction. It allows retaste to create new
geom instance of the same class, while previous one is still dying.
 3) Modifications to some GEOM classes: DEV -- to report media change
events to devd; VFS -- to handle spoiling same as orphan to prevent
accessing replaced media. PART class already handles spoiling alike to
orphan.

Reviewed by:	silence on geom@ and scsi@
Tested by:	avg
Sponsored by:	iXsystems, Inc. / PC-BSD
MFC after:	2 months
2012-07-29 11:51:48 +00:00

321 lines
7.5 KiB
C

/*-
* Copyright (c) 2004 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/vnode.h>
#include <sys/mount.h> /* XXX Temporary for VFS_LOCK_GIANT */
#include <geom/geom.h>
#include <geom/geom_vfs.h>
/*
* subroutines for use by filesystems.
*
* XXX: should maybe live somewhere else ?
*/
#include <sys/buf.h>
struct g_vfs_softc {
struct mtx sc_mtx;
struct bufobj *sc_bo;
int sc_active;
int sc_orphaned;
};
static struct buf_ops __g_vfs_bufops = {
.bop_name = "GEOM_VFS",
.bop_write = bufwrite,
.bop_strategy = g_vfs_strategy,
.bop_sync = bufsync,
.bop_bdflush = bufbdflush
};
struct buf_ops *g_vfs_bufops = &__g_vfs_bufops;
static g_orphan_t g_vfs_orphan;
static g_spoiled_t g_vfs_spoiled;
static struct g_class g_vfs_class = {
.name = "VFS",
.version = G_VERSION,
.orphan = g_vfs_orphan,
.spoiled = g_vfs_spoiled,
};
DECLARE_GEOM_CLASS(g_vfs_class, g_vfs);
static void
g_vfs_destroy(void *arg, int flags __unused)
{
struct g_consumer *cp;
g_topology_assert();
cp = arg;
if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
g_access(cp, -cp->acr, -cp->acw, -cp->ace);
g_detach(cp);
if (cp->geom->softc == NULL)
g_wither_geom(cp->geom, ENXIO);
}
static void
g_vfs_done(struct bio *bip)
{
struct g_consumer *cp;
struct g_vfs_softc *sc;
struct buf *bp;
int vfslocked, destroy;
struct mount *mp;
struct vnode *vp;
struct cdev *cdevp;
/*
* Collect statistics on synchronous and asynchronous read
* and write counts for disks that have associated filesystems.
* Since this run by the g_up thread it is single threaded and
* we do not need to use atomic increments on the counters.
*/
bp = bip->bio_caller2;
vp = bp->b_vp;
if (vp == NULL) {
mp = NULL;
} else {
/*
* If not a disk vnode, use its associated mount point
* otherwise use the mountpoint associated with the disk.
*/
VI_LOCK(vp);
if (vp->v_type != VCHR ||
(cdevp = vp->v_rdev) == NULL ||
cdevp->si_devsw == NULL ||
(cdevp->si_devsw->d_flags & D_DISK) == 0)
mp = vp->v_mount;
else
mp = cdevp->si_mountpt;
VI_UNLOCK(vp);
}
if (mp != NULL) {
if (bp->b_iocmd == BIO_WRITE) {
if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
mp->mnt_stat.f_asyncwrites++;
else
mp->mnt_stat.f_syncwrites++;
} else {
if (LK_HOLDER(bp->b_lock.lk_lock) == LK_KERNPROC)
mp->mnt_stat.f_asyncreads++;
else
mp->mnt_stat.f_syncreads++;
}
}
cp = bip->bio_from;
sc = cp->geom->softc;
if (bip->bio_error) {
printf("g_vfs_done():");
g_print_bio(bip);
printf("error = %d\n", bip->bio_error);
}
bp->b_error = bip->bio_error;
bp->b_ioflags = bip->bio_flags;
if (bip->bio_error)
bp->b_ioflags |= BIO_ERROR;
bp->b_resid = bp->b_bcount - bip->bio_completed;
g_destroy_bio(bip);
mtx_lock(&sc->sc_mtx);
destroy = ((--sc->sc_active) == 0 && sc->sc_orphaned);
mtx_unlock(&sc->sc_mtx);
if (destroy)
g_post_event(g_vfs_destroy, cp, M_WAITOK, NULL);
vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
bufdone(bp);
VFS_UNLOCK_GIANT(vfslocked);
}
void
g_vfs_strategy(struct bufobj *bo, struct buf *bp)
{
struct g_vfs_softc *sc;
struct g_consumer *cp;
struct bio *bip;
int vfslocked;
cp = bo->bo_private;
sc = cp->geom->softc;
/*
* If the provider has orphaned us, just return EXIO.
*/
mtx_lock(&sc->sc_mtx);
if (sc->sc_orphaned) {
mtx_unlock(&sc->sc_mtx);
bp->b_error = ENXIO;
bp->b_ioflags |= BIO_ERROR;
vfslocked = VFS_LOCK_GIANT(((struct mount *)NULL));
bufdone(bp);
VFS_UNLOCK_GIANT(vfslocked);
return;
}
sc->sc_active++;
mtx_unlock(&sc->sc_mtx);
bip = g_alloc_bio();
bip->bio_cmd = bp->b_iocmd;
bip->bio_offset = bp->b_iooffset;
bip->bio_data = bp->b_data;
bip->bio_done = g_vfs_done;
bip->bio_caller2 = bp;
bip->bio_length = bp->b_bcount;
g_io_request(bip, cp);
}
static void
g_vfs_orphan(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_vfs_softc *sc;
int destroy;
g_topology_assert();
gp = cp->geom;
g_trace(G_T_TOPOLOGY, "g_vfs_orphan(%p(%s))", cp, gp->name);
sc = gp->softc;
if (sc == NULL)
return;
mtx_lock(&sc->sc_mtx);
destroy = (sc->sc_active == 0 && sc->sc_orphaned == 0);
sc->sc_orphaned = 1;
mtx_unlock(&sc->sc_mtx);
if (destroy)
g_vfs_destroy(cp, 0);
/*
* Do not destroy the geom. Filesystem will do that during unmount.
*/
}
static void
g_vfs_spoiled(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_vfs_softc *sc;
int destroy;
g_topology_assert();
gp = cp->geom;
g_trace(G_T_TOPOLOGY, "g_vfs_spoiled(%p(%s))", cp, gp->name);
cp->flags |= G_CF_ORPHAN;
sc = gp->softc;
if (sc == NULL)
return;
mtx_lock(&sc->sc_mtx);
destroy = (sc->sc_active == 0 && sc->sc_orphaned == 0);
sc->sc_orphaned = 1;
mtx_unlock(&sc->sc_mtx);
if (destroy)
g_vfs_destroy(cp, 0);
/*
* Do not destroy the geom. Filesystem will do that during unmount.
*/
}
int
g_vfs_open(struct vnode *vp, struct g_consumer **cpp, const char *fsname, int wr)
{
struct g_geom *gp;
struct g_provider *pp;
struct g_consumer *cp;
struct g_vfs_softc *sc;
struct bufobj *bo;
int vfslocked;
int error;
g_topology_assert();
*cpp = NULL;
bo = &vp->v_bufobj;
if (bo->bo_private != vp)
return (EBUSY);
pp = g_dev_getprovider(vp->v_rdev);
if (pp == NULL)
return (ENOENT);
gp = g_new_geomf(&g_vfs_class, "%s.%s", fsname, pp->name);
sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
mtx_init(&sc->sc_mtx, "g_vfs", NULL, MTX_DEF);
sc->sc_bo = bo;
gp->softc = sc;
cp = g_new_consumer(gp);
g_attach(cp, pp);
error = g_access(cp, 1, wr, wr);
if (error) {
g_wither_geom(gp, ENXIO);
return (error);
}
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vnode_create_vobject(vp, pp->mediasize, curthread);
VFS_UNLOCK_GIANT(vfslocked);
*cpp = cp;
cp->private = vp;
bo->bo_ops = g_vfs_bufops;
bo->bo_private = cp;
bo->bo_bsize = pp->sectorsize;
return (error);
}
void
g_vfs_close(struct g_consumer *cp)
{
struct g_geom *gp;
struct g_vfs_softc *sc;
g_topology_assert();
gp = cp->geom;
sc = gp->softc;
bufobj_invalbuf(sc->sc_bo, V_SAVE, 0, 0);
sc->sc_bo->bo_private = cp->private;
gp->softc = NULL;
mtx_destroy(&sc->sc_mtx);
if (!sc->sc_orphaned || cp->provider == NULL)
g_wither_geom_close(gp, ENXIO);
g_free(sc);
}