xfs_log.c

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/*
 * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

/*
 * High level interface routines for log manager
 */

#include "xfs.h"
#include "xfs_macros.h"
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_ag.h"
#include "xfs_sb.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_dir.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_buf_item.h"
#include "xfs_alloc_btree.h"
#include "xfs_log_recover.h"
#include "xfs_bit.h"
#include "xfs_rw.h"
#include "xfs_trans_priv.h"


#define xlog_write_adv_cnt(ptr, len, off, bytes) \
	{ (ptr) += (bytes); \
	  (len) -= (bytes); \
	  (off) += (bytes);}

/* Local miscellaneous function prototypes */
STATIC int	 xlog_bdstrat_cb(struct xfs_buf *);
STATIC int	 xlog_commit_record(xfs_mount_t *mp, xlog_ticket_t *ticket,
				    xlog_in_core_t **, xfs_lsn_t *);
STATIC xlog_t *  xlog_alloc_log(xfs_mount_t	*mp,
				xfs_buftarg_t	*log_target,
				xfs_daddr_t	blk_offset,
				int		num_bblks);
STATIC int	 xlog_space_left(xlog_t *log, int cycle, int bytes);
STATIC int	 xlog_sync(xlog_t *log, xlog_in_core_t *iclog);
STATIC void	 xlog_unalloc_log(xlog_t *log);
STATIC int	 xlog_write(xfs_mount_t *mp, xfs_log_iovec_t region[],
			    int nentries, xfs_log_ticket_t tic,
			    xfs_lsn_t *start_lsn,
			    xlog_in_core_t **commit_iclog,
			    uint flags);

/* local state machine functions */
STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
STATIC void xlog_state_do_callback(xlog_t *log,int aborted, xlog_in_core_t *iclog);
STATIC int  xlog_state_get_iclog_space(xlog_t		*log,
				       int		len,
				       xlog_in_core_t	**iclog,
				       xlog_ticket_t	*ticket,
				       int		*continued_write,
				       int		*logoffsetp);
STATIC void xlog_state_put_ticket(xlog_t	*log,
				  xlog_ticket_t *tic);
STATIC int  xlog_state_release_iclog(xlog_t		*log,
				     xlog_in_core_t	*iclog);
STATIC void xlog_state_switch_iclogs(xlog_t		*log,
				     xlog_in_core_t *iclog,
				     int		eventual_size);
STATIC int  xlog_state_sync(xlog_t *log, xfs_lsn_t lsn, uint flags);
STATIC int  xlog_state_sync_all(xlog_t *log, uint flags);
STATIC void xlog_state_want_sync(xlog_t	*log, xlog_in_core_t *iclog);

/* local functions to manipulate grant head */
STATIC int  xlog_grant_log_space(xlog_t		*log,
				 xlog_ticket_t	*xtic);
STATIC void xlog_grant_push_ail(xfs_mount_t	*mp,
				int		need_bytes);
STATIC void xlog_regrant_reserve_log_space(xlog_t	 *log,
					   xlog_ticket_t *ticket);
STATIC int xlog_regrant_write_log_space(xlog_t		*log,
					 xlog_ticket_t  *ticket);
STATIC void xlog_ungrant_log_space(xlog_t	 *log,
				   xlog_ticket_t *ticket);


/* local ticket functions */
STATIC void		xlog_state_ticket_alloc(xlog_t *log);
STATIC xlog_ticket_t	*xlog_ticket_get(xlog_t *log,
					 int	unit_bytes,
					 int	count,
					 char	clientid,
					 uint	flags);
STATIC void		xlog_ticket_put(xlog_t *log, xlog_ticket_t *ticket);

/* local debug functions */
#if defined(DEBUG) && !defined(XLOG_NOLOG)
STATIC void	xlog_verify_dest_ptr(xlog_t *log, __psint_t ptr);
STATIC void	xlog_verify_grant_head(xlog_t *log, int equals);
STATIC void	xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
				  int count, boolean_t syncing);
STATIC void	xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog,
				     xfs_lsn_t tail_lsn);
#else
#define xlog_verify_dest_ptr(a,b)
#define xlog_verify_grant_head(a,b)
#define xlog_verify_iclog(a,b,c,d)
#define xlog_verify_tail_lsn(a,b,c)
#endif

int		xlog_iclogs_empty(xlog_t *log);

#ifdef DEBUG
int xlog_do_error = 0;
int xlog_req_num  = 0;
int xlog_error_mod = 33;
#endif

#define XLOG_FORCED_SHUTDOWN(log)	(log->l_flags & XLOG_IO_ERROR)

/*
 * 0 => disable log manager
 * 1 => enable log manager
 * 2 => enable log manager and log debugging
 */
#if defined(XLOG_NOLOG) || defined(DEBUG)
int   xlog_debug = 1;
xfs_buftarg_t *xlog_target;
#endif

#if defined(XFS_LOG_TRACE)

void
xlog_trace_loggrant(xlog_t *log, xlog_ticket_t *tic, xfs_caddr_t string)
{
	if (! log->l_grant_trace) {
		log->l_grant_trace = ktrace_alloc(1024, KM_NOSLEEP);
		if (! log->l_grant_trace)
			return;
	}

	ktrace_enter(log->l_grant_trace,
		     (void *)tic,
		     (void *)log->l_reserve_headq,
		     (void *)log->l_write_headq,
		     (void *)((unsigned long)log->l_grant_reserve_cycle),
		     (void *)((unsigned long)log->l_grant_reserve_bytes),
		     (void *)((unsigned long)log->l_grant_write_cycle),
		     (void *)((unsigned long)log->l_grant_write_bytes),
		     (void *)((unsigned long)log->l_curr_cycle),
		     (void *)((unsigned long)log->l_curr_block),
		     (void *)((unsigned long)CYCLE_LSN(log->l_tail_lsn, ARCH_NOCONVERT)),
		     (void *)((unsigned long)BLOCK_LSN(log->l_tail_lsn, ARCH_NOCONVERT)),
		     (void *)string,
		     (void *)((unsigned long)13),
		     (void *)((unsigned long)14),
		     (void *)((unsigned long)15),
		     (void *)((unsigned long)16));
}

void
xlog_trace_iclog(xlog_in_core_t *iclog, uint state)
{
	pid_t pid;

	pid = current_pid();

	if (!iclog->ic_trace)
		iclog->ic_trace = ktrace_alloc(256, KM_SLEEP);
	ktrace_enter(iclog->ic_trace,
		     (void *)((unsigned long)state),
		     (void *)((unsigned long)pid),
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0,
		     (void *)0);
}

#else
#define	xlog_trace_loggrant(log,tic,string)
#define	xlog_trace_iclog(iclog,state)
#endif /* XFS_LOG_TRACE */

/*
 * NOTES:
 *
 *	1. currblock field gets updated at startup and after in-core logs
 *		marked as with WANT_SYNC.
 */

/*
 * This routine is called when a user of a log manager ticket is done with
 * the reservation.  If the ticket was ever used, then a commit record for
 * the associated transaction is written out as a log operation header with
 * no data.  The flag XLOG_TIC_INITED is set when the first write occurs with
 * a given ticket.  If the ticket was one with a permanent reservation, then
 * a few operations are done differently.  Permanent reservation tickets by
 * default don't release the reservation.  They just commit the current
 * transaction with the belief that the reservation is still needed.  A flag
 * must be passed in before permanent reservations are actually released.
 * When these type of tickets are not released, they need to be set into
 * the inited state again.  By doing this, a start record will be written
 * out when the next write occurs.
 */
xfs_lsn_t
xfs_log_done(xfs_mount_t	*mp,
	     xfs_log_ticket_t	xtic,
	     void		**iclog,
	     uint		flags)
{
	xlog_t		*log    = mp->m_log;
	xlog_ticket_t	*ticket = (xfs_log_ticket_t) xtic;
	xfs_lsn_t	lsn	= 0;

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ)
		return 0;
#endif

	if (XLOG_FORCED_SHUTDOWN(log) ||
	    /*
	     * If nothing was ever written, don't write out commit record.
	     * If we get an error, just continue and give back the log ticket.
	     */
	    (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
	     (xlog_commit_record(mp, ticket,
				 (xlog_in_core_t **)iclog, &lsn)))) {
		lsn = (xfs_lsn_t) -1;
		if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
			flags |= XFS_LOG_REL_PERM_RESERV;
		}
	}


	if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
	    (flags & XFS_LOG_REL_PERM_RESERV)) {
		/*
		 * Release ticket if not permanent reservation or a specifc
		 * request has been made to release a permanent reservation.
		 */
		xlog_ungrant_log_space(log, ticket);
		xlog_state_put_ticket(log, ticket);
	} else {
		xlog_regrant_reserve_log_space(log, ticket);
	}

	/* If this ticket was a permanent reservation and we aren't
	 * trying to release it, reset the inited flags; so next time
	 * we write, a start record will be written out.
	 */
	if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) &&
	    (flags & XFS_LOG_REL_PERM_RESERV) == 0)
		ticket->t_flags |= XLOG_TIC_INITED;

	return lsn;
}	/* xfs_log_done */


/*
 * Force the in-core log to disk.  If flags == XFS_LOG_SYNC,
 *	the force is done synchronously.
 *
 * Asynchronous forces are implemented by setting the WANT_SYNC
 * bit in the appropriate in-core log and then returning.
 *
 * Synchronous forces are implemented with a semaphore.  All callers
 * to force a given lsn to disk will wait on a semaphore attached to the
 * specific in-core log.  When given in-core log finally completes its
 * write to disk, that thread will wake up all threads waiting on the
 * semaphore.
 */
int
xfs_log_force(xfs_mount_t *mp,
	      xfs_lsn_t	  lsn,
	      uint	  flags)
{
	int	rval;
	xlog_t *log = mp->m_log;

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ)
		return 0;
#endif

	ASSERT(flags & XFS_LOG_FORCE);

	XFS_STATS_INC(xs_log_force);

	if ((log->l_flags & XLOG_IO_ERROR) == 0) {
		if (lsn == 0)
			rval = xlog_state_sync_all(log, flags);
		else
			rval = xlog_state_sync(log, lsn, flags);
	} else {
		rval = XFS_ERROR(EIO);
	}

	return rval;

}	/* xfs_log_force */

/*
 * Attaches a new iclog I/O completion callback routine during
 * transaction commit.  If the log is in error state, a non-zero
 * return code is handed back and the caller is responsible for
 * executing the callback at an appropriate time.
 */
int
xfs_log_notify(xfs_mount_t	  *mp,		/* mount of partition */
	       void		  *iclog_hndl,	/* iclog to hang callback off */
	       xfs_log_callback_t *cb)
{
	xlog_t *log = mp->m_log;
	xlog_in_core_t	  *iclog = (xlog_in_core_t *)iclog_hndl;
	int	abortflg, spl;

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ)
		return 0;
#endif
	cb->cb_next = NULL;
	spl = LOG_LOCK(log);
	abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
	if (!abortflg) {
		ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
			      (iclog->ic_state == XLOG_STATE_WANT_SYNC));
		cb->cb_next = NULL;
		*(iclog->ic_callback_tail) = cb;
		iclog->ic_callback_tail = &(cb->cb_next);
	}
	LOG_UNLOCK(log, spl);
	return abortflg;
}	/* xfs_log_notify */

int
xfs_log_release_iclog(xfs_mount_t *mp,
		      void	  *iclog_hndl)
{
	xlog_t *log = mp->m_log;
	xlog_in_core_t	  *iclog = (xlog_in_core_t *)iclog_hndl;

	if (xlog_state_release_iclog(log, iclog)) {
		xfs_force_shutdown(mp, XFS_LOG_IO_ERROR);
		return(EIO);
	}

	return 0;
}

/*
 *  1. Reserve an amount of on-disk log space and return a ticket corresponding
 *	to the reservation.
 *  2. Potentially, push buffers at tail of log to disk.
 *
 * Each reservation is going to reserve extra space for a log record header.
 * When writes happen to the on-disk log, we don't subtract the length of the
 * log record header from any reservation.  By wasting space in each
 * reservation, we prevent over allocation problems.
 */
int
xfs_log_reserve(xfs_mount_t	 *mp,
		int		 unit_bytes,
		int		 cnt,
		xfs_log_ticket_t *ticket,
		__uint8_t	 client,
		uint		 flags)
{
	xlog_t		*log = mp->m_log;
	xlog_ticket_t	*internal_ticket;
	int		retval;

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ)
		return 0;
#endif
	retval = 0;
	ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
	ASSERT((flags & XFS_LOG_NOSLEEP) == 0);

	if (XLOG_FORCED_SHUTDOWN(log))
		return XFS_ERROR(EIO);

	XFS_STATS_INC(xs_try_logspace);

	if (*ticket != NULL) {
		ASSERT(flags & XFS_LOG_PERM_RESERV);
		internal_ticket = (xlog_ticket_t *)*ticket;
		xlog_grant_push_ail(mp, internal_ticket->t_unit_res);
		retval = xlog_regrant_write_log_space(log, internal_ticket);
	} else {
		/* may sleep if need to allocate more tickets */
		internal_ticket = xlog_ticket_get(log, unit_bytes, cnt,
						  client, flags);
		*ticket = internal_ticket;
		xlog_grant_push_ail(mp,
				    (internal_ticket->t_unit_res *
				     internal_ticket->t_cnt));
		retval = xlog_grant_log_space(log, internal_ticket);