d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix a bug that caused da(4) instances to hang around after the underlying

Browse Source 
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)
This commit is contained in:
Kenneth D. Merry 2016-06-21 20:18:19 +00:00
parent 9c8809d77f
commit 1ff824e786
2 changed files with 76 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
sys/geom/geom_disk.c
View File

@ -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);

13
sys/geom/geom_disk.h
View File

@ -60,11 +60,21 @@ typedef int disk_ioctl_t(struct disk *, u_long cmd, void *data,
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 flag);
#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_ */