Ejemplo n.º 1
0
static int control_mount(struct gfs2_sbd *sdp)
{
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	uint32_t start_gen, block_gen, mount_gen, lvb_gen;
	int mounted_mode;
	int retries = 0;
	int error;

	memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
	memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
	memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
	ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
	init_completion(&ls->ls_sync_wait);

	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
	if (error) {
		fs_err(sdp, "control_mount control_lock NL error %d\n", error);
		return error;
	}

	error = mounted_lock(sdp, DLM_LOCK_NL, 0);
	if (error) {
		fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
		control_unlock(sdp);
		return error;
	}
	mounted_mode = DLM_LOCK_NL;

restart:
	if (retries++ && signal_pending(current)) {
		error = -EINTR;
		goto fail;
	}

	/*
	 * We always start with both locks in NL. control_lock is
	 * demoted to NL below so we don't need to do it here.
	 */

	if (mounted_mode != DLM_LOCK_NL) {
		error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
		if (error)
			goto fail;
		mounted_mode = DLM_LOCK_NL;
	}

	/*
	 * Other nodes need to do some work in dlm recovery and gfs2_control
	 * before the recover_done and control_lock will be ready for us below.
	 * A delay here is not required but often avoids having to retry.
	 */

	msleep_interruptible(500);

	/*
	 * Acquire control_lock in EX and mounted_lock in either EX or PR.
	 * control_lock lvb keeps track of any pending journal recoveries.
	 * mounted_lock indicates if any other nodes have the fs mounted.
	 */

	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
	if (error == -EAGAIN) {
		goto restart;
	} else if (error) {
		fs_err(sdp, "control_mount control_lock EX error %d\n", error);
		goto fail;
	}

	error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
	if (!error) {
		mounted_mode = DLM_LOCK_EX;
		goto locks_done;
	} else if (error != -EAGAIN) {
		fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
		goto fail;
	}

	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
	if (!error) {
		mounted_mode = DLM_LOCK_PR;
		goto locks_done;
	} else {
		/* not even -EAGAIN should happen here */
		fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
		goto fail;
	}

locks_done:
	/*
	 * If we got both locks above in EX, then we're the first mounter.
	 * If not, then we need to wait for the control_lock lvb to be
	 * updated by other mounted nodes to reflect our mount generation.
	 *
	 * In simple first mounter cases, first mounter will see zero lvb_gen,
	 * but in cases where all existing nodes leave/fail before mounting
	 * nodes finish control_mount, then all nodes will be mounting and
	 * lvb_gen will be non-zero.
	 */

	control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits);

	if (lvb_gen == 0xFFFFFFFF) {
		/* special value to force mount attempts to fail */
		fs_err(sdp, "control_mount control_lock disabled\n");
		error = -EINVAL;
		goto fail;
	}

	if (mounted_mode == DLM_LOCK_EX) {
		/* first mounter, keep both EX while doing first recovery */
		spin_lock(&ls->ls_recover_spin);
		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
		set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
		set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
		return 0;
	}

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
	if (error)
		goto fail;

	/*
	 * We are not first mounter, now we need to wait for the control_lock
	 * lvb generation to be >= the generation from our first recover_done
	 * and all lvb bits to be clear (no pending journal recoveries.)
	 */

	if (!all_jid_bits_clear(ls->ls_lvb_bits)) {
		/* journals need recovery, wait until all are clear */
		fs_info(sdp, "control_mount wait for journal recovery\n");
		goto restart;
	}

	spin_lock(&ls->ls_recover_spin);
	block_gen = ls->ls_recover_block;
	start_gen = ls->ls_recover_start;
	mount_gen = ls->ls_recover_mount;

	if (lvb_gen < mount_gen) {
		/* wait for mounted nodes to update control_lock lvb to our
		   generation, which might include new recovery bits set */
		fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	if (lvb_gen != start_gen) {
		/* wait for mounted nodes to update control_lock lvb to the
		   latest recovery generation */
		fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	if (block_gen == start_gen) {
		/* dlm recovery in progress, wait for it to finish */
		fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
	set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
	spin_unlock(&ls->ls_recover_spin);
	return 0;

fail:
	mounted_unlock(sdp);
	control_unlock(sdp);
	return error;
}
Ejemplo n.º 2
0
static int control_mount(struct gfs2_sbd *sdp)
{
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	char lvb_bits[GDLM_LVB_SIZE];
	uint32_t start_gen, block_gen, mount_gen, lvb_gen;
	int mounted_mode;
	int retries = 0;
	int error;

	memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb));
	memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb));
	memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE);
	ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb;
	init_completion(&ls->ls_sync_wait);

	set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK);
	if (error) {
		fs_err(sdp, "control_mount control_lock NL error %d\n", error);
		return error;
	}

	error = mounted_lock(sdp, DLM_LOCK_NL, 0);
	if (error) {
		fs_err(sdp, "control_mount mounted_lock NL error %d\n", error);
		control_unlock(sdp);
		return error;
	}
	mounted_mode = DLM_LOCK_NL;

restart:
	if (retries++ && signal_pending(current)) {
		error = -EINTR;
		goto fail;
	}


	if (mounted_mode != DLM_LOCK_NL) {
		error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
		if (error)
			goto fail;
		mounted_mode = DLM_LOCK_NL;
	}


	msleep_interruptible(500);


	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK);
	if (error == -EAGAIN) {
		goto restart;
	} else if (error) {
		fs_err(sdp, "control_mount control_lock EX error %d\n", error);
		goto fail;
	}

	error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
	if (!error) {
		mounted_mode = DLM_LOCK_EX;
		goto locks_done;
	} else if (error != -EAGAIN) {
		fs_err(sdp, "control_mount mounted_lock EX error %d\n", error);
		goto fail;
	}

	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE);
	if (!error) {
		mounted_mode = DLM_LOCK_PR;
		goto locks_done;
	} else {
		
		fs_err(sdp, "control_mount mounted_lock PR error %d\n", error);
		goto fail;
	}

locks_done:

	control_lvb_read(ls, &lvb_gen, lvb_bits);

	if (lvb_gen == 0xFFFFFFFF) {
		
		fs_err(sdp, "control_mount control_lock disabled\n");
		error = -EINVAL;
		goto fail;
	}

	if (mounted_mode == DLM_LOCK_EX) {
		
		spin_lock(&ls->ls_recover_spin);
		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
		set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
		set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "first mounter control generation %u\n", lvb_gen);
		return 0;
	}

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
	if (error)
		goto fail;


	if (!all_jid_bits_clear(lvb_bits)) {
		
		fs_info(sdp, "control_mount wait for journal recovery\n");
		goto restart;
	}

	spin_lock(&ls->ls_recover_spin);
	block_gen = ls->ls_recover_block;
	start_gen = ls->ls_recover_start;
	mount_gen = ls->ls_recover_mount;

	if (lvb_gen < mount_gen) {
		fs_info(sdp, "control_mount wait1 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	if (lvb_gen != start_gen) {
		fs_info(sdp, "control_mount wait2 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	if (block_gen == start_gen) {
		
		fs_info(sdp, "control_mount wait3 block %u start %u mount %u "
			"lvb %u flags %lx\n", block_gen, start_gen, mount_gen,
			lvb_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		goto restart;
	}

	clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
	set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags);
	memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t));
	memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t));
	spin_unlock(&ls->ls_recover_spin);
	return 0;

fail:
	mounted_unlock(sdp);
	control_unlock(sdp);
	return error;
}