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

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
...@@ -288,7 +288,162 @@ bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval * ...@@ -288,7 +288,162 @@ bool drbd_al_begin_io_prepare(struct drbd_device *device, struct drbd_interval *
return need_transaction; 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) 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) ...@@ -420,153 +575,6 @@ void drbd_al_complete_io(struct drbd_device *device, struct drbd_interval *i)
wake_up(&device->al_wait); 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) static int _try_lc_del(struct drbd_device *device, struct lc_element *al_ext)
{ {
int rv; int rv;
......
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