Author: ken
Date: Tue Jun 21 20:18:19 2016
New Revision: 302069
URL: https://svnweb.freebsd.org/changeset/base/302069
Log:
Fix a bug that caused da(4) instances to hang around after the underlying
device is gone.
The problem was that when disk_gone() is called, if the GEOM disk
creation process has not yet happened, the withering process
couldn't start.
We didn't record any state in the GEOM disk code, and so the d_gone()
callback to the da(4) driver never happened.
The solution is to track the state of the creation process, and
initiate the withering process from g_disk_create() if the disk is
being created.
This change does add fields to struct disk, and so I have bumped
DISK_VERSION.
geom_disk.c: Track where we are in the disk creation process,
and check to see whether our underlying disk has
gone away or not.
In disk_gone(), set a new d_goneflag variable that
g_disk_create() can check to see if it needs to
clean up the disk instance.
geom_disk.h: Add a mutex to struct disk (for internal use) disk
init level, and a gone flag.
Bump DISK_VERSION because the size of struct disk has
changed and fields have been added at the beginning.
Sponsored by: Spectra Logic
Approved by: re (marius)
Modified:
head/sys/geom/geom_disk.c
head/sys/geom/geom_disk.h
Modified: head/sys/geom/geom_disk.c
==============================================================================
--- head/sys/geom/geom_disk.c Tue Jun 21 20:15:30 2016 (r302068)
+++ head/sys/geom/geom_disk.c Tue Jun 21 20:18:19 2016 (r302069)
@@ -669,6 +669,22 @@ g_disk_create(void *arg, int flag)
return;
g_topology_assert();
dp = arg;
+
+ mtx_lock(&dp->d_mtx);
+ dp->d_init_level = DISK_INIT_START;
+
+ /*
+ * If the disk has already gone away, we can just stop here and
+ * call the user's callback to tell him we've cleaned things up.
+ */
+ if (dp->d_goneflag != 0) {
+ mtx_unlock(&dp->d_mtx);
+ if (dp->d_gone != NULL)
+ dp->d_gone(dp);
+ return;
+ }
+ mtx_unlock(&dp->d_mtx);
+
sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
mtx_init(&sc->start_mtx, "g_disk_start", NULL, MTX_DEF);
mtx_init(&sc->done_mtx, "g_disk_done", NULL, MTX_DEF);
@@ -704,6 +720,21 @@ g_disk_create(void *arg, int flag)
pp->private = sc;
dp->d_geom = gp;
g_error_provider(pp, 0);
+
+ mtx_lock(&dp->d_mtx);
+ dp->d_init_level = DISK_INIT_DONE;
+
+ /*
+ * If the disk has gone away at this stage, start the withering
+ * process for it.
+ */
+ if (dp->d_goneflag != 0) {
+ mtx_unlock(&dp->d_mtx);
+ g_wither_provider(pp, ENXIO);
+ return;
+ }
+ mtx_unlock(&dp->d_mtx);
+
}
/*
@@ -754,6 +785,9 @@ g_disk_destroy(void *ptr, int flag)
dp->d_geom = NULL;
g_wither_geom(gp, ENXIO);
}
+
+ mtx_destroy(&dp->d_mtx);
+
g_free(dp);
}
@@ -817,6 +851,12 @@ disk_create(struct disk *dp, int version
dp->d_sectorsize, DEVSTAT_ALL_SUPPORTED,
DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
dp->d_geom = NULL;
+
+ snprintf(dp->d_mtx_name, sizeof(dp->d_mtx_name), "%s%ddlk",
+ dp->d_name, dp->d_unit);
+ mtx_init(&dp->d_mtx, dp->d_mtx_name, NULL, MTX_DEF);
+ dp->d_init_level = DISK_INIT_NONE;
+
g_disk_ident_adjust(dp->d_ident, sizeof(dp->d_ident));
g_post_event(g_disk_create, dp, M_WAITOK, dp, NULL);
}
@@ -838,6 +878,30 @@ disk_gone(struct disk *dp)
struct g_geom *gp;
struct g_provider *pp;
+ mtx_lock(&dp->d_mtx);
+ dp->d_goneflag = 1;
+
+ /*
+ * If we're still in the process of creating this disk (the
+ * g_disk_create() function is still queued, or is in
+ * progress), the init level will not yet be DISK_INIT_DONE.
+ *
+ * If that is the case, g_disk_create() will see d_goneflag
+ * and take care of cleaning things up.
+ *
+ * If the disk has already been created, we default to
+ * withering the provider as usual below.
+ *
+ * If the caller has not set a d_gone() callback, he will
+ * not be any worse off by returning here, because the geom
+ * has not been fully setup in any case.
+ */
+ if (dp->d_init_level < DISK_INIT_DONE) {
+ mtx_unlock(&dp->d_mtx);
+ return;
+ }
+ mtx_unlock(&dp->d_mtx);
+
gp = dp->d_geom;
if (gp != NULL) {
pp = LIST_FIRST(&gp->provider);
Modified: head/sys/geom/geom_disk.h
==============================================================================
--- head/sys/geom/geom_disk.h Tue Jun 21 20:15:30 2016 (r302068)
+++ head/sys/geom/geom_disk.h Tue Jun 21 20:18:19 2016 (r302069)
@@ -60,11 +60,21 @@ typedef int disk_ioctl_t(struct disk *,
struct g_geom;
struct devstat;
+typedef enum {
+ DISK_INIT_NONE,
+ DISK_INIT_START,
+ DISK_INIT_DONE
+} disk_init_level;
+
struct disk {
/* Fields which are private to geom_disk */
struct g_geom *d_geom;
struct devstat *d_devstat;
+ int d_goneflag;
int d_destroyed;
+ struct mtx d_mtx;
+ char d_mtx_name[24];
+ disk_init_level d_init_level;
/* Shared fields */
u_int d_flags;
@@ -125,7 +135,8 @@ int disk_resize(struct disk *dp, int fla
#define DISK_VERSION_02 0x5856105b
#define DISK_VERSION_03 0x5856105c
#define DISK_VERSION_04 0x5856105d
-#define DISK_VERSION DISK_VERSION_04
+#define DISK_VERSION_05 0x5856105e
+#define DISK_VERSION DISK_VERSION_05
#endif /* _KERNEL */
#endif /* _GEOM_GEOM_DISK_H_ */
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