txg.c File Reference

Pool-wide transaction groups. More...

#include <sys/zfs_context.h>
#include <sys/txg_impl.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_scan.h>
#include <sys/callb.h>

Include dependency graph for txg.c:

Go to the source code of this file.

Functions
static void	txg_sync_thread (void *arg)
static void	txg_quiesce_thread (void *arg)
	SYSCTL_DECL (_vfs_zfs)
	SYSCTL_NODE (_vfs_zfs, OID_AUTO, txg, CTLFLAG_RW, 0,"ZFS TXG")
	TUNABLE_INT ("vfs.zfs.txg.timeout",&zfs_txg_timeout)
	SYSCTL_INT (_vfs_zfs_txg, OID_AUTO, timeout, CTLFLAG_RW,&zfs_txg_timeout, 0,"Maximum seconds worth of delta per txg")
void	txg_init (dsl_pool_t *dp, uint64_t txg)
	Prepares the txg subsystem.
void	txg_fini (dsl_pool_t *dp)
	Closes down the txg subsystem.
void	txg_sync_start (dsl_pool_t *dp)
	Starts syncing transaction groups.
static void	txg_thread_enter (tx_state_t *tx, callb_cpr_t *cpr)
static void	txg_thread_exit (tx_state_t *tx, callb_cpr_t *cpr, kthread_t **tpp)
static void	txg_thread_wait (tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, uint64_t time)
void	txg_sync_stop (dsl_pool_t *dp)
	Stops syncing transaction groups.
uint64_t	txg_hold_open (dsl_pool_t *dp, txg_handle_t *th)
void	txg_rele_to_quiesce (txg_handle_t *th)
void	txg_register_callbacks (txg_handle_t *th, list_t *tx_callbacks)
void	txg_rele_to_sync (txg_handle_t *th)
static void	txg_quiesce (dsl_pool_t *dp, uint64_t txg)
	Blocks until all transactions in the group are released.
static void	txg_do_callbacks (void *arg)
static void	txg_dispatch_callbacks (dsl_pool_t *dp, uint64_t txg)
	Dispatch the commit callbacks registered on this txg.
void	txg_delay (dsl_pool_t *dp, uint64_t txg, int ticks)
	Delay this thread by 'ticks' if we are still in the open transaction group and there is already a waiting txg quiesing or quiesced.
void	txg_wait_synced (dsl_pool_t *dp, uint64_t txg)
	Wait until the given transaction group has finished syncing.
void	txg_wait_open (dsl_pool_t *dp, uint64_t txg)
	Wait until the given transaction group, or one after it, is the open transaction group.
boolean_t	txg_stalled (dsl_pool_t *dp)
	Are we waiting for the syncing transaction to complete?
boolean_t	txg_sync_waiting (dsl_pool_t *dp)
void	txg_list_create (txg_list_t *tl, size_t offset)
	Per-txg object lists.
void	txg_list_destroy (txg_list_t *tl)
boolean_t	txg_list_empty (txg_list_t *tl, uint64_t txg)
int	txg_list_add (txg_list_t *tl, void *p, uint64_t txg)
	Add an entry to the list.
int	txg_list_add_tail (txg_list_t *tl, void *p, uint64_t txg)
	Add an entry to the end of the list (walks list to find end).
void *	txg_list_remove (txg_list_t *tl, uint64_t txg)
	Remove the head of the list and return it.
void *	txg_list_remove_this (txg_list_t *tl, void *p, uint64_t txg)
	Remove a specific item from the list and return it.
int	txg_list_member (txg_list_t *tl, void *p, uint64_t txg)
void *	txg_list_head (txg_list_t *tl, uint64_t txg)
	Walk a txg list - only safe if you know it's not changing.
void *	txg_list_next (txg_list_t *tl, void *p, uint64_t txg)
Variables
int	zfs_txg_timeout = 5
	max seconds worth of delta per txg

---

Detailed Description

Pool-wide transaction groups.

Definition in file txg.c.

---

Function Documentation

SYSCTL_DECL

(

_vfs_zfs

)

SYSCTL_INT	(	_vfs_zfs_txg	,
		OID_AUTO	,
		timeout	,
		CTLFLAG_RW	,
		&	zfs_txg_timeout,
		0	,
		"Maximum seconds worth of delta per txg"
	)

SYSCTL_NODE	(	_vfs_zfs	,
		OID_AUTO	,
		txg	,
		CTLFLAG_RW	,
		0	,
		"ZFS TXG"
	)

TUNABLE_INT	(	"vfs.zfs.txg.timeout"	,
		&	zfs_txg_timeout
	)

void txg_delay	(	dsl_pool_t *	dp,
		uint64_t	txg,
		int	ticks
	)

Delay this thread by 'ticks' if we are still in the open transaction group and there is already a waiting txg quiesing or quiesced.

Delay the caller by the specified number of ticks or until the txg closes (whichever comes first).

Abort the delay if this txg stalls or enters the quiesing state.

Definition at line 509 of file txg.c.

static void txg_dispatch_callbacks	(	dsl_pool_t *	dp,
		uint64_t	txg
	)		[static]

Dispatch the commit callbacks registered on this txg.

If no callbacks are registered for a given TXG, nothing happens. This function creates a taskq for the associated pool, if needed.

Definition at line 343 of file txg.c.

static void txg_do_callbacks

(

void *

arg

)

[static]

Definition at line 325 of file txg.c.

void txg_fini

(

dsl_pool_t *

dp

)

Closes down the txg subsystem.

Definition at line 96 of file txg.c.

uint64_t txg_hold_open	(	dsl_pool_t *	dp,
		txg_handle_t *	th
	)

Definition at line 231 of file txg.c.

void txg_init	(	dsl_pool_t *	dp,
		uint64_t	txg
	)

Prepares the txg subsystem.

Definition at line 60 of file txg.c.

int txg_list_add	(	txg_list_t *	tl,
		void *	p,
		uint64_t	txg
	)

Add an entry to the list.

Returns:

0 if it's a new entry, 1 if it's already there.

Definition at line 631 of file txg.c.

int txg_list_add_tail	(	txg_list_t *	tl,
		void *	p,
		uint64_t	txg
	)

Add an entry to the end of the list (walks list to find end).

Returns:

0 if it's a new entry, 1 if it's already there.

Definition at line 655 of file txg.c.

void txg_list_create	(	txg_list_t *	tl,
		size_t	offset
	)

Per-txg object lists.

Definition at line 596 of file txg.c.

void txg_list_destroy

(

txg_list_t *

tl

)

Definition at line 609 of file txg.c.

boolean_t txg_list_empty	(	txg_list_t *	tl,
		uint64_t	txg
	)

Definition at line 620 of file txg.c.

void* txg_list_head	(	txg_list_t *	tl,
		uint64_t	txg
	)

Walk a txg list - only safe if you know it's not changing.

Definition at line 739 of file txg.c.

int txg_list_member	(	txg_list_t *	tl,
		void *	p,
		uint64_t	txg
	)

Definition at line 727 of file txg.c.

void* txg_list_next	(	txg_list_t *	tl,
		void *	p,
		uint64_t	txg
	)

Definition at line 748 of file txg.c.

void* txg_list_remove	(	txg_list_t *	tl,
		uint64_t	txg
	)

Remove the head of the list and return it.

Definition at line 682 of file txg.c.

void* txg_list_remove_this	(	txg_list_t *	tl,
		void *	p,
		uint64_t	txg
	)

Remove a specific item from the list and return it.

Definition at line 704 of file txg.c.

static void txg_quiesce	(	dsl_pool_t *	dp,
		uint64_t	txg
	)		[static]

Blocks until all transactions in the group are released.

On exit, the transaction group has reached a stable state in which it can then be passed off to the syncing context.

Definition at line 289 of file txg.c.

static void txg_quiesce_thread

(

void *

arg

)

[static]

Definition at line 459 of file txg.c.

void txg_register_callbacks	(	txg_handle_t *	th,
		list_t *	tx_callbacks
	)

Definition at line 257 of file txg.c.

void txg_rele_to_quiesce

(

txg_handle_t *

th

)

Definition at line 249 of file txg.c.

void txg_rele_to_sync

(

txg_handle_t *

th

)

Definition at line 268 of file txg.c.

boolean_t txg_stalled

(

struct dsl_pool *

dp

)

Are we waiting for the syncing transaction to complete?

Return values:

TRUE	We are "backed up" waiting for the syncing transaction to complete
FALSE	Otherwise

Definition at line 577 of file txg.c.

void txg_sync_start

(

dsl_pool_t *

dp

)

Starts syncing transaction groups.

Definition at line 133 of file txg.c.

void txg_sync_stop

(

dsl_pool_t *

dp

)

Stops syncing transaction groups.

Definition at line 194 of file txg.c.

static void txg_sync_thread

(

void *

arg

)

[static]

Definition at line 382 of file txg.c.

boolean_t txg_sync_waiting

(

struct dsl_pool *

dp

)

Returns:

TRUE if someone is waiting for the next txg to sync

Definition at line 584 of file txg.c.

static void txg_thread_enter	(	tx_state_t *	tx,
		callb_cpr_t *	cpr
	)		[static]

Definition at line 160 of file txg.c.

static void txg_thread_exit	(	tx_state_t *	tx,
		callb_cpr_t *	cpr,
		kthread_t **	tpp
	)		[static]

Definition at line 167 of file txg.c.

static void txg_thread_wait	(	tx_state_t *	tx,
		callb_cpr_t *	cpr,
		kcondvar_t *	cv,
		uint64_t	time
	)		[static]

Definition at line 178 of file txg.c.

void txg_wait_open	(	struct dsl_pool *	dp,
		uint64_t	txg
	)

Wait until the given transaction group, or one after it, is the open transaction group.

Try to make this happen as soon as possible (eg. kick off any necessary syncs immediately). If txg == 0, wait for the next open txg.

Definition at line 557 of file txg.c.

void txg_wait_synced	(	struct dsl_pool *	dp,
		uint64_t	txg
	)

Wait until the given transaction group has finished syncing.

Try to make this happen as soon as possible (eg. kick off any necessary syncs immediately). If txg==0, wait for the currently open txg to finish syncing.

Definition at line 534 of file txg.c.