xfs_log.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,167 行 · 第 1/5 页

	}

	return retval;
}	/* xfs_log_reserve */


/*
 * Mount a log filesystem
 *
 * mp		- ubiquitous xfs mount point structure
 * log_target	- buftarg of on-disk log device
 * blk_offset	- Start block # where block size is 512 bytes (BBSIZE)
 * num_bblocks	- Number of BBSIZE blocks in on-disk log
 *
 * Return error or zero.
 */
int
xfs_log_mount(xfs_mount_t	*mp,
	      xfs_buftarg_t	*log_target,
	      xfs_daddr_t	blk_offset,
	      int		num_bblks)
{
	if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
		cmn_err(CE_NOTE, "XFS mounting filesystem %s", mp->m_fsname);
	else {
		cmn_err(CE_NOTE,
			"!Mounting filesystem \"%s\" in no-recovery mode.  Filesystem will be inconsistent.",
			mp->m_fsname);
		ASSERT(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY);
	}

	mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug) {
		cmn_err(CE_NOTE, "log dev: %s", XFS_BUFTARG_NAME(log_target));
		return 0;
	}
#endif
	/*
	 * skip log recovery on a norecovery mount.  pretend it all
	 * just worked.
	 */
	if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
		int	error;
		vfs_t	*vfsp = XFS_MTOVFS(mp);
		int	readonly = (vfsp->vfs_flag & VFS_RDONLY);

		if (readonly)
			vfsp->vfs_flag &= ~VFS_RDONLY;

		error = xlog_recover(mp->m_log, readonly);

		if (readonly)
			vfsp->vfs_flag |= VFS_RDONLY;
		if (error) {
			cmn_err(CE_WARN, "XFS: log mount/recovery failed: error %d", error);
			xlog_unalloc_log(mp->m_log);
			return error;
		}
	}

	/* Normal transactions can now occur */
	mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;

	/* End mounting message in xfs_log_mount_finish */
	return 0;
}	/* xfs_log_mount */

/*
 * Finish the recovery of the file system.  This is separate from
 * the xfs_log_mount() call, because it depends on the code in
 * xfs_mountfs() to read in the root and real-time bitmap inodes
 * between calling xfs_log_mount() and here.
 *
 * mp		- ubiquitous xfs mount point structure
 */
int
xfs_log_mount_finish(xfs_mount_t *mp, int mfsi_flags)
{
	int	error;

	if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
		error = xlog_recover_finish(mp->m_log, mfsi_flags);
	else {
		error = 0;
		ASSERT(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY);
	}

	return error;
}

/*
 * Unmount processing for the log.
 */
int
xfs_log_unmount(xfs_mount_t *mp)
{
	int		error;

	error = xfs_log_unmount_write(mp);
	xfs_log_unmount_dealloc(mp);
	return (error);
}

/*
 * Final log writes as part of unmount.
 *
 * Mark the filesystem clean as unmount happens.  Note that during relocation
 * this routine needs to be executed as part of source-bag while the
 * deallocation must not be done until source-end.
 */

/*
 * Unmount record used to have a string "Unmount filesystem--" in the
 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
 * We just write the magic number now since that particular field isn't
 * currently architecture converted and "nUmount" is a bit foo.
 * As far as I know, there weren't any dependencies on the old behaviour.
 */

int
xfs_log_unmount_write(xfs_mount_t *mp)
{
	xlog_t		 *log = mp->m_log;
	xlog_in_core_t	 *iclog;
#ifdef DEBUG
	xlog_in_core_t	 *first_iclog;
#endif
	xfs_log_iovec_t  reg[1];
	xfs_log_ticket_t tic = NULL;
	xfs_lsn_t	 lsn;
	int		 error;
	SPLDECL(s);

	/* the data section must be 32 bit size aligned */
	struct {
	    __uint16_t magic;
	    __uint16_t pad1;
	    __uint32_t pad2; /* may as well make it 64 bits */
	} magic = { XLOG_UNMOUNT_TYPE, 0, 0 };

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

	/*
	 * Don't write out unmount record on read-only mounts.
	 * Or, if we are doing a forced umount (typically because of IO errors).
	 */
	if (XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY)
		return 0;

	xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC);

#ifdef DEBUG
	first_iclog = iclog = log->l_iclog;
	do {
		if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
			ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
			ASSERT(iclog->ic_offset == 0);
		}
		iclog = iclog->ic_next;
	} while (iclog != first_iclog);
#endif
	if (! (XLOG_FORCED_SHUTDOWN(log))) {
		reg[0].i_addr = (void*)&magic;
		reg[0].i_len  = sizeof(magic);

		error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
		if (!error) {
			/* remove inited flag */
			((xlog_ticket_t *)tic)->t_flags = 0;
			error = xlog_write(mp, reg, 1, tic, &lsn,
					   NULL, XLOG_UNMOUNT_TRANS);
			/*
			 * At this point, we're umounting anyway,
			 * so there's no point in transitioning log state
			 * to IOERROR. Just continue...
			 */
		}

		if (error) {
			xfs_fs_cmn_err(CE_ALERT, mp,
				"xfs_log_unmount: unmount record failed");
		}


		s = LOG_LOCK(log);
		iclog = log->l_iclog;
		iclog->ic_refcnt++;
		LOG_UNLOCK(log, s);
		xlog_state_want_sync(log, iclog);
		(void) xlog_state_release_iclog(log, iclog);

		s = LOG_LOCK(log);
		if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
		      iclog->ic_state == XLOG_STATE_DIRTY)) {
			if (!XLOG_FORCED_SHUTDOWN(log)) {
				sv_wait(&iclog->ic_forcesema, PMEM,
					&log->l_icloglock, s);
			} else {
				LOG_UNLOCK(log, s);
			}
		} else {
			LOG_UNLOCK(log, s);
		}
		if (tic)
			xlog_state_put_ticket(log, tic);
	} else {
		/*
		 * We're already in forced_shutdown mode, couldn't
		 * even attempt to write out the unmount transaction.
		 *
		 * Go through the motions of sync'ing and releasing
		 * the iclog, even though no I/O will actually happen,
		 * we need to wait for other log I/O's that may already
		 * be in progress.  Do this as a separate section of
		 * code so we'll know if we ever get stuck here that
		 * we're in this odd situation of trying to unmount
		 * a file system that went into forced_shutdown as
		 * the result of an unmount..
		 */
		s = LOG_LOCK(log);
		iclog = log->l_iclog;
		iclog->ic_refcnt++;
		LOG_UNLOCK(log, s);

		xlog_state_want_sync(log, iclog);
		(void) xlog_state_release_iclog(log, iclog);

		s = LOG_LOCK(log);

		if ( ! (   iclog->ic_state == XLOG_STATE_ACTIVE
			|| iclog->ic_state == XLOG_STATE_DIRTY
			|| iclog->ic_state == XLOG_STATE_IOERROR) ) {

				sv_wait(&iclog->ic_forcesema, PMEM,
					&log->l_icloglock, s);
		} else {
			LOG_UNLOCK(log, s);
		}
	}

	return 0;
}	/* xfs_log_unmount_write */

/*
 * Deallocate log structures for unmount/relocation.
 */
void
xfs_log_unmount_dealloc(xfs_mount_t *mp)
{
	xlog_unalloc_log(mp->m_log);
}

/*
 * Write region vectors to log.  The write happens using the space reservation
 * of the ticket (tic).  It is not a requirement that all writes for a given
 * transaction occur with one call to xfs_log_write().
 */
int
xfs_log_write(xfs_mount_t *	mp,
	      xfs_log_iovec_t	reg[],
	      int		nentries,
	      xfs_log_ticket_t	tic,
	      xfs_lsn_t		*start_lsn)
{
	int	error;
	xlog_t *log = mp->m_log;

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ) {
		*start_lsn = 0;
		return 0;
	}
#endif
	if (XLOG_FORCED_SHUTDOWN(log))
		return XFS_ERROR(EIO);

	if ((error = xlog_write(mp, reg, nentries, tic, start_lsn, NULL, 0))) {
		xfs_force_shutdown(mp, XFS_LOG_IO_ERROR);
	}
	return (error);
}	/* xfs_log_write */


void
xfs_log_move_tail(xfs_mount_t	*mp,
		  xfs_lsn_t	tail_lsn)
{
	xlog_ticket_t	*tic;
	xlog_t		*log = mp->m_log;
	int		need_bytes, free_bytes, cycle, bytes;
	SPLDECL(s);

#if defined(DEBUG) || defined(XLOG_NOLOG)
	if (!xlog_debug && xlog_target == log->l_targ)
		return;
#endif
	/* XXXsup tmp */
	if (XLOG_FORCED_SHUTDOWN(log))
		return;
	ASSERT(!XFS_FORCED_SHUTDOWN(mp));

	if (tail_lsn == 0) {
		/* needed since sync_lsn is 64 bits */
		s = LOG_LOCK(log);
		tail_lsn = log->l_last_sync_lsn;
		LOG_UNLOCK(log, s);
	}

	s = GRANT_LOCK(log);

	/* Also an invalid lsn.  1 implies that we aren't passing in a valid
	 * tail_lsn.
	 */
	if (tail_lsn != 1) {
		log->l_tail_lsn = tail_lsn;
	}

	if ((tic = log->l_write_headq)) {
#ifdef DEBUG
		if (log->l_flags & XLOG_ACTIVE_RECOVERY)
			panic("Recovery problem");
#endif
		cycle = log->l_grant_write_cycle;
		bytes = log->l_grant_write_bytes;
		free_bytes = xlog_space_left(log, cycle, bytes);
		do {
			ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);

			if (free_bytes < tic->t_unit_res && tail_lsn != 1)
				break;
			tail_lsn = 0;
			free_bytes -= tic->t_unit_res;
			sv_signal(&tic->t_sema);
			tic = tic->t_next;
		} while (tic != log->l_write_headq);
	}
	if ((tic = log->l_reserve_headq)) {
#ifdef DEBUG
		if (log->l_flags & XLOG_ACTIVE_RECOVERY)
			panic("Recovery problem");
#endif
		cycle = log->l_grant_reserve_cycle;
		bytes = log->l_grant_reserve_bytes;
		free_bytes = xlog_space_left(log, cycle, bytes);
		do {
			if (tic->t_flags & XLOG_TIC_PERM_RESERV)
				need_bytes = tic->t_unit_res*tic->t_cnt;
			else
				need_bytes = tic->t_unit_res;
			if (free_bytes < need_bytes && tail_lsn != 1)
				break;
			tail_lsn = 0;
			free_bytes -= need_bytes;
			sv_signal(&tic->t_sema);
			tic = tic->t_next;
		} while (tic != log->l_reserve_headq);
	}
	GRANT_UNLOCK(log, s);
}	/* xfs_log_move_tail */

/*
 * Determine if we have a transaction that has gone to disk
 * that needs to be covered. Log activity needs to be idle (no AIL and
 * nothing in the iclogs). And, we need to be in the right state indicating
 * something has gone out.
 */
int
xfs_log_need_covered(xfs_mount_t *mp)
{
	SPLDECL(s);
	int		needed = 0, gen;
	xlog_t		*log = mp->m_log;
	vfs_t		*vfsp = XFS_MTOVFS(mp);

	if (fs_frozen(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
	    (vfsp->vfs_flag & VFS_RDONLY))
		return 0;

	s = LOG_LOCK(log);
	if (((log->l_covered_state == XLOG_STATE_COVER_NEED) ||
		(log->l_covered_state == XLOG_STATE_COVER_NEED2))
			&& !xfs_trans_first_ail(mp, &gen)
			&& xlog_iclogs_empty(log)) {
		if (log->l_covered_state == XLOG_STATE_COVER_NEED)
			log->l_covered_state = XLOG_STATE_COVER_DONE;
		else {
			ASSERT(log->l_covered_state == XLOG_STATE_COVER_NEED2);
			log->l_covered_state = XLOG_STATE_COVER_DONE2;
		}
		needed = 1;
	}
	LOG_UNLOCK(log, s);
	return(needed);
}

/******************************************************************************
 *
 *	local routines
 *
 ******************************************************************************
 */

/* xfs_trans_tail_ail returns 0 when there is nothing in the list.
 * The log manager must keep track of the last LR which was committed
 * to disk.  The lsn of this LR will become the new tail_lsn whenever
 * xfs_trans_tail_ail returns 0.  If we don't do this, we run into
 * the situation where stuff could be written into the log but nothing
 * was ever in the AIL when asked.  Eventually, we panic since the
 * tail hits the head.
 *
 * We may be holding the log iclog lock upon entering this routine.
 */
xfs_lsn_t
xlog_assign_tail_lsn(xfs_mount_t *mp)
{
	xfs_lsn_t tail_lsn;
	SPLDECL(s);
	xlog_t	  *log = mp->m_log;

	tail_lsn = xfs_trans_tail_ail(mp);
	s = GRANT_LOCK(log);
	if (tail_lsn != 0) {
		log->l_tail_lsn = tail_lsn;
	} else {
		tail_lsn = log->l_tail_lsn = log->l_last_sync_lsn;
	}
	GRANT_UNLOCK(log, s);

	return tail_lsn;