svn commit: r208142 -
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs
Pawel Jakub Dawidek
pjd at FreeBSD.org
Sun May 16 11:56:43 UTC 2010
Author: pjd
Date: Sun May 16 11:56:42 2010
New Revision: 208142
URL: http://svn.freebsd.org/changeset/base/208142
Log:
The whole point of having dedicated worker thread for each leaf VDEV was to
avoid calling zio_interrupt() from geom_up thread context. It turns out that
when provider is forcibly removed from the system and we kill worker thread
there can still be some ZIOs pending. To complete pending ZIOs when there is
no worker thread anymore we still have to call zio_interrupt() from geom_up
context. To avoid this race just remove use of worker threads altogether.
This should be more or less fine, because I also thought that zio_interrupt()
does more work, but it only makes small UMA allocation with M_WAITOK.
It also saves one context switch per I/O request.
PR: kern/145339
Reported by: Alex Bakhtin <Alex.Bakhtin at gmail.com>
MFC after: 1 week
Modified:
head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c Sun May 16 11:17:21 2010 (r208141)
+++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c Sun May 16 11:56:42 2010 (r208142)
@@ -47,31 +47,6 @@ struct g_class zfs_vdev_class = {
DECLARE_GEOM_CLASS(zfs_vdev_class, zfs_vdev);
-typedef struct vdev_geom_ctx {
- struct g_consumer *gc_consumer;
- int gc_state;
- struct bio_queue_head gc_queue;
- struct mtx gc_queue_mtx;
-} vdev_geom_ctx_t;
-
-static void
-vdev_geom_release(vdev_t *vd)
-{
- vdev_geom_ctx_t *ctx;
-
- ctx = vd->vdev_tsd;
- vd->vdev_tsd = NULL;
-
- mtx_lock(&ctx->gc_queue_mtx);
- ctx->gc_state = 1;
- wakeup_one(&ctx->gc_queue);
- while (ctx->gc_state != 2)
- msleep(&ctx->gc_state, &ctx->gc_queue_mtx, 0, "vgeom:w", 0);
- mtx_unlock(&ctx->gc_queue_mtx);
- mtx_destroy(&ctx->gc_queue_mtx);
- kmem_free(ctx, sizeof(*ctx));
-}
-
static void
vdev_geom_orphan(struct g_consumer *cp)
{
@@ -96,8 +71,7 @@ vdev_geom_orphan(struct g_consumer *cp)
ZFS_LOG(1, "Destroyed geom %s.", gp->name);
g_wither_geom(gp, error);
}
- vdev_geom_release(vd);
-
+ vd->vdev_tsd = NULL;
vd->vdev_remove_wanted = B_TRUE;
spa_async_request(vd->vdev_spa, SPA_ASYNC_REMOVE);
}
@@ -188,52 +162,6 @@ vdev_geom_detach(void *arg, int flag __u
}
}
-static void
-vdev_geom_worker(void *arg)
-{
- vdev_geom_ctx_t *ctx;
- zio_t *zio;
- struct bio *bp;
-
- thread_lock(curthread);
- sched_prio(curthread, PRIBIO);
- thread_unlock(curthread);
-
- ctx = arg;
- for (;;) {
- mtx_lock(&ctx->gc_queue_mtx);
- bp = bioq_takefirst(&ctx->gc_queue);
- if (bp == NULL) {
- if (ctx->gc_state == 1) {
- ctx->gc_state = 2;
- wakeup_one(&ctx->gc_state);
- mtx_unlock(&ctx->gc_queue_mtx);
- kthread_exit();
- }
- msleep(&ctx->gc_queue, &ctx->gc_queue_mtx,
- PRIBIO | PDROP, "vgeom:io", 0);
- continue;
- }
- mtx_unlock(&ctx->gc_queue_mtx);
- zio = bp->bio_caller1;
- zio->io_error = bp->bio_error;
- if (bp->bio_cmd == BIO_FLUSH && bp->bio_error == ENOTSUP) {
- vdev_t *vd;
-
- /*
- * If we get ENOTSUP, we know that no future
- * attempts will ever succeed. In this case we
- * set a persistent bit so that we don't bother
- * with the ioctl in the future.
- */
- vd = zio->io_vd;
- vd->vdev_nowritecache = B_TRUE;
- }
- g_destroy_bio(bp);
- zio_interrupt(zio);
- }
-}
-
static uint64_t
nvlist_get_guid(nvlist_t *list)
{
@@ -488,7 +416,6 @@ vdev_geom_open_by_path(vdev_t *vd, int c
static int
vdev_geom_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
{
- vdev_geom_ctx_t *ctx;
struct g_provider *pp;
struct g_consumer *cp;
int error, owned;
@@ -557,19 +484,9 @@ vdev_geom_open(vdev_t *vd, uint64_t *psi
}
cp->private = vd;
-
- ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP);
- bioq_init(&ctx->gc_queue);
- mtx_init(&ctx->gc_queue_mtx, "zfs:vdev:geom:queue", NULL, MTX_DEF);
- ctx->gc_consumer = cp;
- ctx->gc_state = 0;
-
- vd->vdev_tsd = ctx;
+ vd->vdev_tsd = cp;
pp = cp->provider;
- kproc_kthread_add(vdev_geom_worker, ctx, &zfsproc, NULL, 0, 0,
- "zfskern", "vdev %s", pp->name);
-
/*
* Determine the actual size of the device.
*/
@@ -592,50 +509,49 @@ vdev_geom_open(vdev_t *vd, uint64_t *psi
static void
vdev_geom_close(vdev_t *vd)
{
- vdev_geom_ctx_t *ctx;
struct g_consumer *cp;
- if ((ctx = vd->vdev_tsd) == NULL)
- return;
- if ((cp = ctx->gc_consumer) == NULL)
+ cp = vd->vdev_tsd;
+ if (cp == NULL)
return;
- vdev_geom_release(vd);
+ vd->vdev_tsd = NULL;
g_post_event(vdev_geom_detach, cp, M_WAITOK, NULL);
}
static void
vdev_geom_io_intr(struct bio *bp)
{
- vdev_geom_ctx_t *ctx;
zio_t *zio;
zio = bp->bio_caller1;
- ctx = zio->io_vd->vdev_tsd;
-
- if ((zio->io_error = bp->bio_error) == 0 && bp->bio_resid != 0)
+ zio->io_error = bp->bio_error;
+ if (zio->io_error == 0 && bp->bio_resid != 0)
zio->io_error = EIO;
+ if (bp->bio_cmd == BIO_FLUSH && bp->bio_error == ENOTSUP) {
+ vdev_t *vd;
- mtx_lock(&ctx->gc_queue_mtx);
- bioq_insert_tail(&ctx->gc_queue, bp);
- wakeup_one(&ctx->gc_queue);
- mtx_unlock(&ctx->gc_queue_mtx);
+ /*
+ * If we get ENOTSUP, we know that no future
+ * attempts will ever succeed. In this case we
+ * set a persistent bit so that we don't bother
+ * with the ioctl in the future.
+ */
+ vd = zio->io_vd;
+ vd->vdev_nowritecache = B_TRUE;
+ }
+ g_destroy_bio(bp);
+ zio_interrupt(zio);
}
static int
vdev_geom_io_start(zio_t *zio)
{
vdev_t *vd;
- vdev_geom_ctx_t *ctx;
struct g_consumer *cp;
struct bio *bp;
int error;
- cp = NULL;
-
vd = zio->io_vd;
- ctx = vd->vdev_tsd;
- if (ctx != NULL)
- cp = ctx->gc_consumer;
if (zio->io_type == ZIO_TYPE_IOCTL) {
/* XXPOLICY */
@@ -664,6 +580,7 @@ vdev_geom_io_start(zio_t *zio)
return (ZIO_PIPELINE_CONTINUE);
}
sendreq:
+ cp = vd->vdev_tsd;
if (cp == NULL) {
zio->io_error = ENXIO;
return (ZIO_PIPELINE_CONTINUE);
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