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Commit 603ee2c8 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Jens Axboe
Browse files

drbd: separate out __al_write_transaction helper function 



To be able to "force out" an activity log transaction,
even if there are no pending updates.

This will be used to relocate the on-disk activity log,
if the on-disk offsets have to be changed,
without the need to empty the activity log first.

While at it, move the definition,
so we can drop the forward declaration of a static helper.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 7dbb4386

drivers/block/drbd/drbd_actlog.c

+156 −148
Original line number Diff line number Diff line
@@ -288,7 +288,162 @@ bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval * 
	return need_transaction;

}



static int al_write_transaction(struct drbd_device *device);

#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)

/* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT

 * are still coupled, or assume too much about their relation.

 * Code below will not work if this is violated.

 * Will be cleaned up with some followup patch.

 */

# error FIXME

#endif



static unsigned int al_extent_to_bm_page(unsigned int al_enr)

{

	return al_enr >>

		/* bit to page */

		((PAGE_SHIFT + 3) -

		/* al extent number to bit */

		 (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));

}



static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device)

{

	const unsigned int stripes = device->ldev->md.al_stripes;

	const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k;



	/* transaction number, modulo on-disk ring buffer wrap around */

	unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k);



	/* ... to aligned 4k on disk block */

	t = ((t % stripes) * stripe_size_4kB) + t/stripes;



	/* ... to 512 byte sector in activity log */

	t *= 8;



	/* ... plus offset to the on disk position */

	return device->ldev->md.md_offset + device->ldev->md.al_offset + t;

}



static int __al_write_transaction(struct drbd_device *device, struct al_transaction_on_disk *buffer)

{

	struct lc_element *e;

	sector_t sector;

	int i, mx;

	unsigned extent_nr;

	unsigned crc = 0;

	int err = 0;



	memset(buffer, 0, sizeof(*buffer));

	buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);

	buffer->tr_number = cpu_to_be32(device->al_tr_number);



	i = 0;



	/* Even though no one can start to change this list

	 * once we set the LC_LOCKED -- from drbd_al_begin_io(),

	 * lc_try_lock_for_transaction() --, someone may still

	 * be in the process of changing it. */

	spin_lock_irq(&device->al_lock);

	list_for_each_entry(e, &device->act_log->to_be_changed, list) {

		if (i == AL_UPDATES_PER_TRANSACTION) {

			i++;

			break;

		}

		buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);

		buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);

		if (e->lc_number != LC_FREE)

			drbd_bm_mark_for_writeout(device,

					al_extent_to_bm_page(e->lc_number));

		i++;

	}

	spin_unlock_irq(&device->al_lock);

	BUG_ON(i > AL_UPDATES_PER_TRANSACTION);



	buffer->n_updates = cpu_to_be16(i);

	for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {

		buffer->update_slot_nr[i] = cpu_to_be16(-1);

		buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);

	}



	buffer->context_size = cpu_to_be16(device->act_log->nr_elements);

	buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle);



	mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,

		   device->act_log->nr_elements - device->al_tr_cycle);

	for (i = 0; i < mx; i++) {

		unsigned idx = device->al_tr_cycle + i;

		extent_nr = lc_element_by_index(device->act_log, idx)->lc_number;

		buffer->context[i] = cpu_to_be32(extent_nr);

	}

	for (; i < AL_CONTEXT_PER_TRANSACTION; i++)

		buffer->context[i] = cpu_to_be32(LC_FREE);



	device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;

	if (device->al_tr_cycle >= device->act_log->nr_elements)

		device->al_tr_cycle = 0;



	sector = al_tr_number_to_on_disk_sector(device);



	crc = crc32c(0, buffer, 4096);

	buffer->crc32c = cpu_to_be32(crc);



	if (drbd_bm_write_hinted(device))

		err = -EIO;

	else {

		bool write_al_updates;

		rcu_read_lock();

		write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates;

		rcu_read_unlock();

		if (write_al_updates) {

			if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) {

				err = -EIO;

				drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);

			} else {

				device->al_tr_number++;

				device->al_writ_cnt++;

			}

		}

	}



	return err;

}



static int al_write_transaction(struct drbd_device *device)

{

	struct al_transaction_on_disk *buffer;

	int err;



	if (!get_ldev(device)) {

		drbd_err(device, "disk is %s, cannot start al transaction\n",

			drbd_disk_str(device->state.disk));

		return -EIO;

	}



	/* The bitmap write may have failed, causing a state change. */

	if (device->state.disk < D_INCONSISTENT) {

		drbd_err(device,

			"disk is %s, cannot write al transaction\n",

			drbd_disk_str(device->state.disk));

		put_ldev(device);

		return -EIO;

	}



	/* protects md_io_buffer, al_tr_cycle, ... */

	buffer = drbd_md_get_buffer(device, __func__);

	if (!buffer) {

		drbd_err(device, "disk failed while waiting for md_io buffer\n");

		put_ldev(device);

		return -ENODEV;

	}



	err = __al_write_transaction(device, buffer);



	drbd_md_put_buffer(device);

	put_ldev(device);



	return err;

}





void drbd_al_begin_io_commit(struct drbd_device *device)

{
@@ -420,153 +575,6 @@ void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i) 
	wake_up(&device->al_wait);

}



#if (PAGE_SHIFT + 3) < (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT)

/* Currently BM_BLOCK_SHIFT, BM_EXT_SHIFT and AL_EXTENT_SHIFT

 * are still coupled, or assume too much about their relation.

 * Code below will not work if this is violated.

 * Will be cleaned up with some followup patch.

 */

# error FIXME

#endif



static unsigned int al_extent_to_bm_page(unsigned int al_enr)

{

	return al_enr >>

		/* bit to page */

		((PAGE_SHIFT + 3) -

		/* al extent number to bit */

		 (AL_EXTENT_SHIFT - BM_BLOCK_SHIFT));

}



static sector_t al_tr_number_to_on_disk_sector(struct drbd_device *device)

{

	const unsigned int stripes = device->ldev->md.al_stripes;

	const unsigned int stripe_size_4kB = device->ldev->md.al_stripe_size_4k;



	/* transaction number, modulo on-disk ring buffer wrap around */

	unsigned int t = device->al_tr_number % (device->ldev->md.al_size_4k);



	/* ... to aligned 4k on disk block */

	t = ((t % stripes) * stripe_size_4kB) + t/stripes;



	/* ... to 512 byte sector in activity log */

	t *= 8;



	/* ... plus offset to the on disk position */

	return device->ldev->md.md_offset + device->ldev->md.al_offset + t;

}



int al_write_transaction(struct drbd_device *device)

{

	struct al_transaction_on_disk *buffer;

	struct lc_element *e;

	sector_t sector;

	int i, mx;

	unsigned extent_nr;

	unsigned crc = 0;

	int err = 0;



	if (!get_ldev(device)) {

		drbd_err(device, "disk is %s, cannot start al transaction\n",

			drbd_disk_str(device->state.disk));

		return -EIO;

	}



	/* The bitmap write may have failed, causing a state change. */

	if (device->state.disk < D_INCONSISTENT) {

		drbd_err(device,

			"disk is %s, cannot write al transaction\n",

			drbd_disk_str(device->state.disk));

		put_ldev(device);

		return -EIO;

	}



	/* protects md_io_buffer, al_tr_cycle, ... */

	buffer = drbd_md_get_buffer(device, __func__);

	if (!buffer) {

		drbd_err(device, "disk failed while waiting for md_io buffer\n");

		put_ldev(device);

		return -ENODEV;

	}



	memset(buffer, 0, sizeof(*buffer));

	buffer->magic = cpu_to_be32(DRBD_AL_MAGIC);

	buffer->tr_number = cpu_to_be32(device->al_tr_number);



	i = 0;



	/* Even though no one can start to change this list

	 * once we set the LC_LOCKED -- from drbd_al_begin_io(),

	 * lc_try_lock_for_transaction() --, someone may still

	 * be in the process of changing it. */

	spin_lock_irq(&device->al_lock);

	list_for_each_entry(e, &device->act_log->to_be_changed, list) {

		if (i == AL_UPDATES_PER_TRANSACTION) {

			i++;

			break;

		}

		buffer->update_slot_nr[i] = cpu_to_be16(e->lc_index);

		buffer->update_extent_nr[i] = cpu_to_be32(e->lc_new_number);

		if (e->lc_number != LC_FREE)

			drbd_bm_mark_for_writeout(device,

					al_extent_to_bm_page(e->lc_number));

		i++;

	}

	spin_unlock_irq(&device->al_lock);

	BUG_ON(i > AL_UPDATES_PER_TRANSACTION);



	buffer->n_updates = cpu_to_be16(i);

	for ( ; i < AL_UPDATES_PER_TRANSACTION; i++) {

		buffer->update_slot_nr[i] = cpu_to_be16(-1);

		buffer->update_extent_nr[i] = cpu_to_be32(LC_FREE);

	}



	buffer->context_size = cpu_to_be16(device->act_log->nr_elements);

	buffer->context_start_slot_nr = cpu_to_be16(device->al_tr_cycle);



	mx = min_t(int, AL_CONTEXT_PER_TRANSACTION,

		   device->act_log->nr_elements - device->al_tr_cycle);

	for (i = 0; i < mx; i++) {

		unsigned idx = device->al_tr_cycle + i;

		extent_nr = lc_element_by_index(device->act_log, idx)->lc_number;

		buffer->context[i] = cpu_to_be32(extent_nr);

	}

	for (; i < AL_CONTEXT_PER_TRANSACTION; i++)

		buffer->context[i] = cpu_to_be32(LC_FREE);



	device->al_tr_cycle += AL_CONTEXT_PER_TRANSACTION;

	if (device->al_tr_cycle >= device->act_log->nr_elements)

		device->al_tr_cycle = 0;



	sector = al_tr_number_to_on_disk_sector(device);



	crc = crc32c(0, buffer, 4096);

	buffer->crc32c = cpu_to_be32(crc);



	if (drbd_bm_write_hinted(device))

		err = -EIO;

	else {

		bool write_al_updates;

		rcu_read_lock();

		write_al_updates = rcu_dereference(device->ldev->disk_conf)->al_updates;

		rcu_read_unlock();

		if (write_al_updates) {

			if (drbd_md_sync_page_io(device, device->ldev, sector, WRITE)) {

				err = -EIO;

				drbd_chk_io_error(device, 1, DRBD_META_IO_ERROR);

			} else {

				device->al_tr_number++;

				device->al_writ_cnt++;

			}

		}

	}



	drbd_md_put_buffer(device);

	put_ldev(device);



	return err;

}



static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext)

{

	int rv;