Create a sysctl kern.cam.{,a,n}da.X.invalidate

kern.cam.{,a,n}da.X.invalidate=1 forces *daX to detach by calling
cam_periph_invalidate on the underlying periph. This is for testing
purposes only. Include only with options CAM_TEST_FAILURE and rename
the former [AN]DA_TEST_FAILURE, and fix nda to compile with it set.
We're using it at work to harden geom and the buffer cache to be
resilient in the face of drive failure. Today, it far too often
results in a panic. While much work was done on SIM initiated removal
for the USB thumnb drive removal work, little has been done for periph
initiated removal. This simulates what *daerror() does for some errors
nicely: we get the same panics with it that we do with failing drives.

Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D14581
This commit is contained in:
Warner Losh 2018-03-14 17:53:37 +00:00
parent 2a559cb8c8
commit d38677d23c
7 changed files with 54 additions and 5 deletions

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@ -238,7 +238,7 @@ struct ada_softc {
int write_cache;
int unmappedio;
int rotating;
#ifdef ADA_TEST_FAILURE
#ifdef CAM_TEST_FAILURE
int force_read_error;
int force_write_error;
int periodic_read_error;
@ -1475,7 +1475,7 @@ adasysctlinit(void *context, int pending)
"max_seq_zones", CTLFLAG_RD, &softc->max_seq_zones,
"Maximum Number of Open Sequential Write Required Zones");
#ifdef ADA_TEST_FAILURE
#ifdef CAM_TEST_FAILURE
/*
* Add a 'door bell' sysctl which allows one to set it from userland
* and cause something bad to happen. For the moment, we only allow
@ -1493,6 +1493,10 @@ adasysctlinit(void *context, int pending)
OID_AUTO, "periodic_read_error", CTLFLAG_RW | CTLFLAG_MPSAFE,
&softc->periodic_read_error, 0,
"Force a read error every N reads (don't set too low).");
SYSCTL_ADD_PROC(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
OID_AUTO, "invalidate", CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE,
periph, 0, cam_periph_invalidate_sysctl, "I",
"Write 1 to invalidate the drive immediately");
#endif
#ifdef CAM_IO_STATS
@ -2293,7 +2297,7 @@ adastart(struct cam_periph *periph, union ccb *start_ccb)
data_ptr = bp;
}
#ifdef ADA_TEST_FAILURE
#ifdef CAM_TEST_FAILURE
int fail = 0;
/*

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@ -2066,3 +2066,25 @@ cam_periph_devctl_notify(union ccb *ccb)
free(sbmsg, M_CAMPERIPH);
}
/*
* Sysctl to force an invalidation of the drive right now. Can be
* called with CTLFLAG_MPSAFE since we take periph lock.
*/
int
cam_periph_invalidate_sysctl(SYSCTL_HANDLER_ARGS)
{
struct cam_periph *periph;
int error, value;
periph = arg1;
value = 0;
error = sysctl_handle_int(oidp, &value, 0, req);
if (error != 0 || req->newptr == NULL || value != 1)
return (error);
cam_periph_lock(periph);
cam_periph_invalidate(periph);
cam_periph_unlock(periph);
return (0);
}

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@ -37,6 +37,7 @@
#include <cam/cam_sim.h>
#ifdef _KERNEL
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <cam/cam_xpt.h>
@ -198,6 +199,7 @@ void cam_periph_freeze_after_event(struct cam_periph *periph,
u_int duration_ms);
int cam_periph_error(union ccb *ccb, cam_flags camflags,
u_int32_t sense_flags);
int cam_periph_invalidate_sysctl(SYSCTL_HANDLER_ARGS);
static __inline struct mtx *
cam_periph_mtx(struct cam_periph *periph)

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@ -112,6 +112,12 @@ struct nda_softc {
struct task sysctl_task;
struct sysctl_ctx_list sysctl_ctx;
struct sysctl_oid *sysctl_tree;
#ifdef CAM_TEST_FAILURE
int force_read_error;
int force_write_error;
int periodic_read_error;
int periodic_read_count;
#endif
#ifdef CAM_IO_STATS
struct sysctl_ctx_list sysctl_stats_ctx;
struct sysctl_oid *sysctl_stats_tree;
@ -666,6 +672,13 @@ ndasysctlinit(void *context, int pending)
"Device pack invalidations.");
#endif
#ifdef CAM_TEST_FAILURE
SYSCTL_ADD_PROC(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
OID_AUTO, "invalidate", CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE,
periph, 0, cam_periph_invalidate_sysctl, "I",
"Write 1 to invalidate the drive immediately");
#endif
cam_iosched_sysctl_init(softc->cam_iosched, &softc->sysctl_ctx,
softc->sysctl_tree);
@ -876,7 +889,7 @@ ndastart(struct cam_periph *periph, union ccb *start_ccb)
/* FALLTHROUGH */
case BIO_READ:
{
#ifdef NDA_TEST_FAILURE
#ifdef CAM_TEST_FAILURE
int fail = 0;
/*

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@ -2203,6 +2203,13 @@ dasysctlinit(void *context, int pending)
0,
"Rotating media");
#ifdef CAM_TEST_FAILURE
SYSCTL_ADD_PROC(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
OID_AUTO, "invalidate", CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE,
periph, 0, cam_periph_invalidate_sysctl, "I",
"Write 1 to invalidate the drive immediately");
#endif
/*
* Add some addressing info.
*/

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@ -1356,6 +1356,7 @@ options SCSI_NO_SENSE_STRINGS
options SCSI_NO_OP_STRINGS
options SCSI_DELAY=5000 # Be pessimistic about Joe SCSI device
options CAM_IOSCHED_DYNAMIC
options CAM_TEST_FAILURE
# Options for the CAM CDROM driver:
# CHANGER_MIN_BUSY_SECONDS: Guaranteed minimum time quantum for a changer LUN

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@ -335,12 +335,12 @@ CAM_DEBUG_LUN opt_cam.h
CAM_DEBUG_FLAGS opt_cam.h
CAM_BOOT_DELAY opt_cam.h
CAM_IOSCHED_DYNAMIC opt_cam.h
CAM_TEST_FAILURE opt_cam.h
SCSI_DELAY opt_scsi.h
SCSI_NO_SENSE_STRINGS opt_scsi.h
SCSI_NO_OP_STRINGS opt_scsi.h
# Options used only in cam/ata/ata_da.c
ADA_TEST_FAILURE opt_ada.h
ATA_STATIC_ID opt_ada.h
# Options used only in cam/scsi/scsi_cd.c