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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2013 by Delphix. All rights reserved.
*/
/*
* ZFS fault injection
*
* To handle fault injection, we keep track of a series of zinject_record_t
* structures which describe which logical block(s) should be injected with a
* fault. These are kept in a global list. Each record corresponds to a given
* spa_t and maintains a special hold on the spa_t so that it cannot be deleted
* or exported while the injection record exists.
*
* Device level injection is done using the 'zi_guid' field. If this is set, it
* means that the error is destined for a particular device, not a piece of
* data.
*
* This is a rather poor data structure and algorithm, but we don't expect more
* than a few faults at any one time, so it should be sufficient for our needs.
*/
#include <sys/arc.h>
#include <sys/zio_impl.h>
#include <sys/zfs_ioctl.h>
#include <sys/vdev_impl.h>
#include <sys/dmu_objset.h>
#include <sys/fs/zfs.h>
uint32_t zio_injection_enabled;
typedef struct inject_handler {
int zi_id;
spa_t *zi_spa;
zinject_record_t zi_record;
list_node_t zi_link;
} inject_handler_t;
static list_t inject_handlers;
static krwlock_t inject_lock;
static int inject_next_id = 1;
/*
* Returns true if the given record matches the I/O in progress.
*/
static boolean_t
zio_match_handler(zbookmark_t *zb, uint64_t type,
zinject_record_t *record, int error)
{
/*
* Check for a match against the MOS, which is based on type
*/
if (zb->zb_objset == DMU_META_OBJSET &&
record->zi_objset == DMU_META_OBJSET &&
record->zi_object == DMU_META_DNODE_OBJECT) {
if (record->zi_type == DMU_OT_NONE ||
type == record->zi_type)
return (record->zi_freq == 0 ||
spa_get_random(100) < record->zi_freq);
else
return (B_FALSE);
}
/*
* Check for an exact match.
*/
if (zb->zb_objset == record->zi_objset &&
zb->zb_object == record->zi_object &&
zb->zb_level == record->zi_level &&
zb->zb_blkid >= record->zi_start &&
zb->zb_blkid <= record->zi_end &&
error == record->zi_error)
return (record->zi_freq == 0 ||
spa_get_random(100) < record->zi_freq);
return (B_FALSE);
}
/*
* Panic the system when a config change happens in the function
* specified by tag.
*/
void
zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type)
{
inject_handler_t *handler;
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
if (spa != handler->zi_spa)
continue;
if (handler->zi_record.zi_type == type &&
strcmp(tag, handler->zi_record.zi_func) == 0)
panic("Panic requested in function %s\n", tag);
}
rw_exit(&inject_lock);
}
/*
* Determine if the I/O in question should return failure. Returns the errno
* to be returned to the caller.
*/
int
zio_handle_fault_injection(zio_t *zio, int error)
{
int ret = 0;
inject_handler_t *handler;
/*
* Ignore I/O not associated with any logical data.
*/
if (zio->io_logical == NULL)
return (0);
/*
* Currently, we only support fault injection on reads.
*/
if (zio->io_type != ZIO_TYPE_READ)
return (0);
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
if (zio->io_spa != handler->zi_spa ||
handler->zi_record.zi_cmd != ZINJECT_DATA_FAULT)
continue;
/* If this handler matches, return EIO */
if (zio_match_handler(&zio->io_logical->io_bookmark,
zio->io_bp ? BP_GET_TYPE(zio->io_bp) : DMU_OT_NONE,
&handler->zi_record, error)) {
ret = error;
break;
}
}
rw_exit(&inject_lock);
return (ret);
}
/*
* Determine if the zio is part of a label update and has an injection
* handler associated with that portion of the label. Currently, we
* allow error injection in either the nvlist or the uberblock region of
* of the vdev label.
*/
int
zio_handle_label_injection(zio_t *zio, int error)
{
inject_handler_t *handler;
vdev_t *vd = zio->io_vd;
uint64_t offset = zio->io_offset;
int label;
int ret = 0;
if (offset >= VDEV_LABEL_START_SIZE &&
offset < vd->vdev_psize - VDEV_LABEL_END_SIZE)
return (0);
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
uint64_t start = handler->zi_record.zi_start;
uint64_t end = handler->zi_record.zi_end;
if (handler->zi_record.zi_cmd != ZINJECT_LABEL_FAULT)
continue;
/*
* The injection region is the relative offsets within a
* vdev label. We must determine the label which is being
* updated and adjust our region accordingly.
*/
label = vdev_label_number(vd->vdev_psize, offset);
start = vdev_label_offset(vd->vdev_psize, label, start);
end = vdev_label_offset(vd->vdev_psize, label, end);
if (zio->io_vd->vdev_guid == handler->zi_record.zi_guid &&
(offset >= start && offset <= end)) {
ret = error;
break;
}
}
rw_exit(&inject_lock);
return (ret);
}
int
zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error)
{
inject_handler_t *handler;
int ret = 0;
/*
* We skip over faults in the labels unless it's during
* device open (i.e. zio == NULL).
*/
if (zio != NULL) {
uint64_t offset = zio->io_offset;
if (offset < VDEV_LABEL_START_SIZE ||
offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE)
return (0);
}
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
if (handler->zi_record.zi_cmd != ZINJECT_DEVICE_FAULT)
continue;
if (vd->vdev_guid == handler->zi_record.zi_guid) {
if (handler->zi_record.zi_failfast &&
(zio == NULL || (zio->io_flags &
(ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))) {
continue;
}
/* Handle type specific I/O failures */
if (zio != NULL &&
handler->zi_record.zi_iotype != ZIO_TYPES &&
handler->zi_record.zi_iotype != zio->io_type)
continue;
if (handler->zi_record.zi_error == error) {
/*
* For a failed open, pretend like the device
* has gone away.
*/
if (error == ENXIO)
vd->vdev_stat.vs_aux =
VDEV_AUX_OPEN_FAILED;
/*
* Treat these errors as if they had been
* retried so that all the appropriate stats
* and FMA events are generated.
*/
if (!handler->zi_record.zi_failfast &&
zio != NULL)
zio->io_flags |= ZIO_FLAG_IO_RETRY;
ret = error;
break;
}
if (handler->zi_record.zi_error == ENXIO) {
ret = SET_ERROR(EIO);
break;
}
}
}
rw_exit(&inject_lock);
return (ret);
}
/*
* Simulate hardware that ignores cache flushes. For requested number
* of seconds nix the actual writing to disk.
*/
void
zio_handle_ignored_writes(zio_t *zio)
{
inject_handler_t *handler;
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
/* Ignore errors not destined for this pool */
if (zio->io_spa != handler->zi_spa ||
handler->zi_record.zi_cmd != ZINJECT_IGNORED_WRITES)
continue;
/*
* Positive duration implies # of seconds, negative
* a number of txgs
*/
if (handler->zi_record.zi_timer == 0) {
if (handler->zi_record.zi_duration > 0)
handler->zi_record.zi_timer = ddi_get_lbolt64();
else
handler->zi_record.zi_timer = zio->io_txg;
}
/* Have a "problem" writing 60% of the time */
if (spa_get_random(100) < 60)
zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
break;
}
rw_exit(&inject_lock);
}
void
spa_handle_ignored_writes(spa_t *spa)
{
inject_handler_t *handler;
if (zio_injection_enabled == 0)
return;
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
if (spa != handler->zi_spa ||
handler->zi_record.zi_cmd != ZINJECT_IGNORED_WRITES)
continue;
if (handler->zi_record.zi_duration > 0) {
VERIFY(handler->zi_record.zi_timer == 0 ||
handler->zi_record.zi_timer +
handler->zi_record.zi_duration * hz >
ddi_get_lbolt64());
} else {
/* duration is negative so the subtraction here adds */
VERIFY(handler->zi_record.zi_timer == 0 ||
handler->zi_record.zi_timer -
handler->zi_record.zi_duration >=
spa_syncing_txg(spa));
}
}
rw_exit(&inject_lock);
}
uint64_t
zio_handle_io_delay(zio_t *zio)
{
vdev_t *vd = zio->io_vd;
inject_handler_t *handler;
uint64_t seconds = 0;
if (zio_injection_enabled == 0)
return (0);
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler)) {
if (handler->zi_record.zi_cmd != ZINJECT_DELAY_IO)
continue;
if (vd->vdev_guid == handler->zi_record.zi_guid) {
seconds = handler->zi_record.zi_timer;
break;
}
}
rw_exit(&inject_lock);
return (seconds);
}
/*
* Create a new handler for the given record. We add it to the list, adding
* a reference to the spa_t in the process. We increment zio_injection_enabled,
* which is the switch to trigger all fault injection.
*/
int
zio_inject_fault(char *name, int flags, int *id, zinject_record_t *record)
{
inject_handler_t *handler;
int error;
spa_t *spa;
/*
* If this is pool-wide metadata, make sure we unload the corresponding
* spa_t, so that the next attempt to load it will trigger the fault.
* We call spa_reset() to unload the pool appropriately.
*/
if (flags & ZINJECT_UNLOAD_SPA)
if ((error = spa_reset(name)) != 0)
return (error);
if (!(flags & ZINJECT_NULL)) {
/*
* spa_inject_ref() will add an injection reference, which will
* prevent the pool from being removed from the namespace while
* still allowing it to be unloaded.
*/
if ((spa = spa_inject_addref(name)) == NULL)
return (SET_ERROR(ENOENT));
handler = kmem_alloc(sizeof (inject_handler_t), KM_SLEEP);
rw_enter(&inject_lock, RW_WRITER);
*id = handler->zi_id = inject_next_id++;
handler->zi_spa = spa;
handler->zi_record = *record;
list_insert_tail(&inject_handlers, handler);
atomic_add_32(&zio_injection_enabled, 1);
rw_exit(&inject_lock);
}
/*
* Flush the ARC, so that any attempts to read this data will end up
* going to the ZIO layer. Note that this is a little overkill, but
* we don't have the necessary ARC interfaces to do anything else, and
* fault injection isn't a performance critical path.
*/
if (flags & ZINJECT_FLUSH_ARC)
arc_flush(NULL);
return (0);
}
/*
* Returns the next record with an ID greater than that supplied to the
* function. Used to iterate over all handlers in the system.
*/
int
zio_inject_list_next(int *id, char *name, size_t buflen,
zinject_record_t *record)
{
inject_handler_t *handler;
int ret;
mutex_enter(&spa_namespace_lock);
rw_enter(&inject_lock, RW_READER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler))
if (handler->zi_id > *id)
break;
if (handler) {
*record = handler->zi_record;
*id = handler->zi_id;
(void) strncpy(name, spa_name(handler->zi_spa), buflen);
ret = 0;
} else {
ret = SET_ERROR(ENOENT);
}
rw_exit(&inject_lock);
mutex_exit(&spa_namespace_lock);
return (ret);
}
/*
* Clear the fault handler with the given identifier, or return ENOENT if none
* exists.
*/
int
zio_clear_fault(int id)
{
inject_handler_t *handler;
rw_enter(&inject_lock, RW_WRITER);
for (handler = list_head(&inject_handlers); handler != NULL;
handler = list_next(&inject_handlers, handler))
if (handler->zi_id == id)
break;
if (handler == NULL) {
rw_exit(&inject_lock);
return (SET_ERROR(ENOENT));
}
list_remove(&inject_handlers, handler);
rw_exit(&inject_lock);
spa_inject_delref(handler->zi_spa);
kmem_free(handler, sizeof (inject_handler_t));
atomic_add_32(&zio_injection_enabled, -1);
return (0);
}
void
zio_inject_init(void)
{
rw_init(&inject_lock, NULL, RW_DEFAULT, NULL);
list_create(&inject_handlers, sizeof (inject_handler_t),
offsetof(inject_handler_t, zi_link));
}
void
zio_inject_fini(void)
{
list_destroy(&inject_handlers);
rw_destroy(&inject_lock);
}
|