static int control_first_done(struct gfs2_sbd *sdp)
{
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	char lvb_bits[GDLM_LVB_SIZE];
	uint32_t start_gen, block_gen;
	int error;

restart:
	spin_lock(&ls->ls_recover_spin);
	start_gen = ls->ls_recover_start;
	block_gen = ls->ls_recover_block;

	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
	    !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
	    !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
		/* sanity check, should not happen */
		fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
		       start_gen, block_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		control_unlock(sdp);
		return -1;
	}

	if (start_gen == block_gen) {
		/*
		 * Wait for the end of a dlm recovery cycle to switch from
		 * first mounter recovery.  We can ignore any recover_slot
		 * callbacks between the recover_prep and next recover_done
		 * because we are still the first mounter and any failed nodes
		 * have not fully mounted, so they don't need recovery.
		 */
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "control_first_done wait gen %u\n", start_gen);

		wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
			    dlm_recovery_wait, TASK_UNINTERRUPTIBLE);
		goto restart;
	}

	clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
	set_bit(DFL_FIRST_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);

	memset(lvb_bits, 0, sizeof(lvb_bits));
	control_lvb_write(ls, start_gen, lvb_bits);

	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
	if (error)
		fs_err(sdp, "control_first_done mounted PR error %d\n", error);

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
	if (error)
		fs_err(sdp, "control_first_done control NL error %d\n", error);

	return error;
}
static int control_first_done(struct gfs2_sbd *sdp)
{
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	char lvb_bits[GDLM_LVB_SIZE];
	uint32_t start_gen, block_gen;
	int error;

restart:
	spin_lock(&ls->ls_recover_spin);
	start_gen = ls->ls_recover_start;
	block_gen = ls->ls_recover_block;

	if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) ||
	    !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
	    !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
		/*                                 */
		fs_err(sdp, "control_first_done start %u block %u flags %lx\n",
		       start_gen, block_gen, ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		control_unlock(sdp);
		return -1;
	}

	if (start_gen == block_gen) {
		/*
                                                            
                                                            
                                                             
                                                                
                                                         
   */
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "control_first_done wait gen %u\n", start_gen);

		wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY,
			    dlm_recovery_wait, TASK_UNINTERRUPTIBLE);
		goto restart;
	}

	clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags);
	set_bit(DFL_FIRST_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);

	memset(lvb_bits, 0, sizeof(lvb_bits));
	control_lvb_write(ls, start_gen, lvb_bits);

	error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT);
	if (error)
		fs_err(sdp, "control_first_done mounted PR error %d\n", error);

	error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
	if (error)
		fs_err(sdp, "control_first_done control NL error %d\n", error);

	return error;
}
static void gfs2_control_func(struct work_struct *work)
{
	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	uint32_t block_gen, start_gen, lvb_gen, flags;
	int recover_set = 0;
	int write_lvb = 0;
	int recover_size;
	int i, error;

	spin_lock(&ls->ls_recover_spin);
	/*
	 * No MOUNT_DONE means we're still mounting; control_mount()
	 * will set this flag, after which this thread will take over
	 * all further clearing of BLOCK_LOCKS.
	 *
	 * FIRST_MOUNT means this node is doing first mounter recovery,
	 * for which recovery control is handled by
	 * control_mount()/control_first_done(), not this thread.
	 */
	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
		spin_unlock(&ls->ls_recover_spin);
		return;
	}
	block_gen = ls->ls_recover_block;
	start_gen = ls->ls_recover_start;
	spin_unlock(&ls->ls_recover_spin);

	/*
	 * Equal block_gen and start_gen implies we are between
	 * recover_prep and recover_done callbacks, which means
	 * dlm recovery is in progress and dlm locking is blocked.
	 * There's no point trying to do any work until recover_done.
	 */

	if (block_gen == start_gen)
		return;

	/*
	 * Propagate recover_submit[] and recover_result[] to lvb:
	 * dlm_recoverd adds to recover_submit[] jids needing recovery
	 * gfs2_recover adds to recover_result[] journal recovery results
	 *
	 * set lvb bit for jids in recover_submit[] if the lvb has not
	 * yet been updated for the generation of the failure
	 *
	 * clear lvb bit for jids in recover_result[] if the result of
	 * the journal recovery is SUCCESS
	 */

	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
	if (error) {
		fs_err(sdp, "control lock EX error %d\n", error);
		return;
	}

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

	spin_lock(&ls->ls_recover_spin);
	if (block_gen != ls->ls_recover_block ||
	    start_gen != ls->ls_recover_start) {
		fs_info(sdp, "recover generation %u block1 %u %u\n",
			start_gen, block_gen, ls->ls_recover_block);
		spin_unlock(&ls->ls_recover_spin);
		control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
		return;
	}

	recover_size = ls->ls_recover_size;

	if (lvb_gen <= start_gen) {
		/*
		 * Clear lvb bits for jids we've successfully recovered.
		 * Because all nodes attempt to recover failed journals,
		 * a journal can be recovered multiple times successfully
		 * in succession.  Only the first will really do recovery,
		 * the others find it clean, but still report a successful
		 * recovery.  So, another node may have already recovered
		 * the jid and cleared the lvb bit for it.
		 */
		for (i = 0; i < recover_size; i++) {
			if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
				continue;

			ls->ls_recover_result[i] = 0;

			if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET))
				continue;

			__clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
			write_lvb = 1;
		}
	}

	if (lvb_gen == start_gen) {
		/*
		 * Failed slots before start_gen are already set in lvb.
		 */
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])
				continue;
			if (ls->ls_recover_submit[i] < lvb_gen)
				ls->ls_recover_submit[i] = 0;
		}
	} else if (lvb_gen < start_gen) {
		/*
		 * Failed slots before start_gen are not yet set in lvb.
		 */
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])
				continue;
			if (ls->ls_recover_submit[i] < start_gen) {
				ls->ls_recover_submit[i] = 0;
				__set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET);
			}
		}
		/* even if there are no bits to set, we need to write the
		   latest generation to the lvb */
		write_lvb = 1;
	} else {
		/*
		 * we should be getting a recover_done() for lvb_gen soon
		 */
	}
	spin_unlock(&ls->ls_recover_spin);

	if (write_lvb) {
		control_lvb_write(ls, start_gen, ls->ls_lvb_bits);
		flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
	} else {
		flags = DLM_LKF_CONVERT;
	}

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

	/*
	 * Everyone will see jid bits set in the lvb, run gfs2_recover_set(),
	 * and clear a jid bit in the lvb if the recovery is a success.
	 * Eventually all journals will be recovered, all jid bits will
	 * be cleared in the lvb, and everyone will clear BLOCK_LOCKS.
	 */

	for (i = 0; i < recover_size; i++) {
		if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) {
			fs_info(sdp, "recover generation %u jid %d\n",
				start_gen, i);
			gfs2_recover_set(sdp, i);
			recover_set++;
		}
	}
	if (recover_set)
		return;

	/*
	 * No more jid bits set in lvb, all recovery is done, unblock locks
	 * (unless a new recover_prep callback has occured blocking locks
	 * again while working above)
	 */

	spin_lock(&ls->ls_recover_spin);
	if (ls->ls_recover_block == block_gen &&
	    ls->ls_recover_start == start_gen) {
		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "recover generation %u done\n", start_gen);
		gfs2_glock_thaw(sdp);
	} else {
		fs_info(sdp, "recover generation %u block2 %u %u\n",
			start_gen, block_gen, ls->ls_recover_block);
		spin_unlock(&ls->ls_recover_spin);
	}
}
static void gfs2_control_func(struct work_struct *work)
{
	struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work);
	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
	char lvb_bits[GDLM_LVB_SIZE];
	uint32_t block_gen, start_gen, lvb_gen, flags;
	int recover_set = 0;
	int write_lvb = 0;
	int recover_size;
	int i, error;

	spin_lock(&ls->ls_recover_spin);
	if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) ||
	     test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) {
		spin_unlock(&ls->ls_recover_spin);
		return;
	}
	block_gen = ls->ls_recover_block;
	start_gen = ls->ls_recover_start;
	spin_unlock(&ls->ls_recover_spin);


	if (block_gen == start_gen)
		return;


	error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
	if (error) {
		fs_err(sdp, "control lock EX error %d\n", error);
		return;
	}

	control_lvb_read(ls, &lvb_gen, lvb_bits);

	spin_lock(&ls->ls_recover_spin);
	if (block_gen != ls->ls_recover_block ||
	    start_gen != ls->ls_recover_start) {
		fs_info(sdp, "recover generation %u block1 %u %u\n",
			start_gen, block_gen, ls->ls_recover_block);
		spin_unlock(&ls->ls_recover_spin);
		control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT);
		return;
	}

	recover_size = ls->ls_recover_size;

	if (lvb_gen <= start_gen) {
		for (i = 0; i < recover_size; i++) {
			if (ls->ls_recover_result[i] != LM_RD_SUCCESS)
				continue;

			ls->ls_recover_result[i] = 0;

			if (!test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET))
				continue;

			__clear_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
			write_lvb = 1;
		}
	}

	if (lvb_gen == start_gen) {
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])
				continue;
			if (ls->ls_recover_submit[i] < lvb_gen)
				ls->ls_recover_submit[i] = 0;
		}
	} else if (lvb_gen < start_gen) {
		for (i = 0; i < recover_size; i++) {
			if (!ls->ls_recover_submit[i])
				continue;
			if (ls->ls_recover_submit[i] < start_gen) {
				ls->ls_recover_submit[i] = 0;
				__set_bit_le(i, lvb_bits + JID_BITMAP_OFFSET);
			}
		}
		write_lvb = 1;
	} else {
	}
	spin_unlock(&ls->ls_recover_spin);

	if (write_lvb) {
		control_lvb_write(ls, start_gen, lvb_bits);
		flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK;
	} else {
		flags = DLM_LKF_CONVERT;
	}

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


	for (i = 0; i < recover_size; i++) {
		if (test_bit_le(i, lvb_bits + JID_BITMAP_OFFSET)) {
			fs_info(sdp, "recover generation %u jid %d\n",
				start_gen, i);
			gfs2_recover_set(sdp, i);
			recover_set++;
		}
	}
	if (recover_set)
		return;


	spin_lock(&ls->ls_recover_spin);
	if (ls->ls_recover_block == block_gen &&
	    ls->ls_recover_start == start_gen) {
		clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags);
		spin_unlock(&ls->ls_recover_spin);
		fs_info(sdp, "recover generation %u done\n", start_gen);
		gfs2_glock_thaw(sdp);
	} else {
		fs_info(sdp, "recover generation %u block2 %u %u\n",
			start_gen, block_gen, ls->ls_recover_block);
		spin_unlock(&ls->ls_recover_spin);
	}
}