zio_inject.c File Reference

ZFS fault injection. More...

#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>

Include dependency graph for zio_inject.c:

Go to the source code of this file.

Data Structures
struct	inject_handler
Typedefs
typedef struct inject_handler	inject_handler_t
Functions
static boolean_t	zio_match_handler (zbookmark_t *zb, uint64_t type, zinject_record_t *record, int error)
	Returns true if the given record matches the I/O in progress.
void	zio_handle_panic_injection (spa_t *spa, char *tag, uint64_t type)
	Panic the system when a config change happens in the function specified by tag.
int	zio_handle_fault_injection (zio_t *zio, int error)
	Determine if the I/O in question should return failure.
int	zio_handle_label_injection (zio_t *zio, int error)
	Determine if the zio is part of a label update and has an injection handler associated with that portion of the label.
int	zio_handle_device_injection (vdev_t *vd, zio_t *zio, int error)
void	zio_handle_ignored_writes (zio_t *zio)
	Simulate hardware that ignores cache flushes.
void	spa_handle_ignored_writes (spa_t *spa)
	Called from spa_sync(), but primarily an injection handler.
int	zio_inject_fault (char *name, int flags, int *id, zinject_record_t *record)
	Create a new handler for the given record.
int	zio_inject_list_next (int *id, char *name, size_t buflen, zinject_record_t *record)
	Returns the next record with an ID greater than that supplied to the function.
int	zio_clear_fault (int id)
	Clear the fault handler with the given identifier, or return ENOENT if none exists.
void	zio_inject_init (void)
void	zio_inject_fini (void)
Variables
uint32_t	zio_injection_enabled
static list_t	inject_handlers
static krwlock_t	inject_lock
static int	inject_next_id = 1

---

Detailed Description

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.

Definition in file zio_inject.c.

---

Typedef Documentation

typedef struct inject_handler inject_handler_t

---

Function Documentation

void spa_handle_ignored_writes

(

spa_t *

spa

)

Called from spa_sync(), but primarily an injection handler.

Definition at line 347 of file zio_inject.c.

int zio_clear_fault

(

int

id

)

Clear the fault handler with the given identifier, or return ENOENT if none exists.

Definition at line 477 of file zio_inject.c.

int zio_handle_device_injection	(	vdev_t *	vd,
		zio_t *	zio,
		int	error
	)

Definition at line 228 of file zio_inject.c.

int zio_handle_fault_injection	(	zio_t *	zio,
		int	error
	)

Determine if the I/O in question should return failure.

Returns the errno to be returned to the caller.

Definition at line 129 of file zio_inject.c.

void zio_handle_ignored_writes

(

zio_t *

zio

)

Simulate hardware that ignores cache flushes.

For requested number of seconds nix the actual writing to disk.

Definition at line 310 of file zio_inject.c.

int zio_handle_label_injection	(	zio_t *	zio,
		int	error
	)

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.

Definition at line 182 of file zio_inject.c.

void zio_handle_panic_injection	(	spa_t *	spa,
		char *	tag,
		uint64_t	type
	)

Panic the system when a config change happens in the function specified by tag.

Definition at line 104 of file zio_inject.c.

int zio_inject_fault	(	char *	name,
		int	flags,
		int *	id,
		zinject_record_t *	record
	)

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.

Definition at line 389 of file zio_inject.c.

void zio_inject_fini

(

void

)

Definition at line 512 of file zio_inject.c.

void zio_inject_init

(

void

)

Definition at line 504 of file zio_inject.c.

int zio_inject_list_next	(	int *	id,
		char *	name,
		size_t	buflen,
		zinject_record_t *	record
	)

Returns the next record with an ID greater than that supplied to the function.

Used to iterate over all handlers in the system.

Definition at line 443 of file zio_inject.c.

static boolean_t zio_match_handler	(	zbookmark_t *	zb,
		uint64_t	type,
		zinject_record_t *	record,
		int	error
	)		[static]

Returns true if the given record matches the I/O in progress.

Definition at line 67 of file zio_inject.c.

---

Variable Documentation

list_t inject_handlers [static]

Definition at line 59 of file zio_inject.c.

krwlock_t inject_lock [static]

Definition at line 60 of file zio_inject.c.

int inject_next_id = 1 [static]

Definition at line 61 of file zio_inject.c.

uint32_t zio_injection_enabled

Definition at line 50 of file zio_inject.c.