btrfs: zoned: wait for extent buffer IOs before finishing a zone

Before sending REQ_OP_ZONE_FINISH to a zone, we need to ensure that
ongoing IOs already finished. Or, we will see a "Zone Is Full" error for
the IOs, as the ZONE_FINISH command makes the zone full.

We ensure that with btrfs_wait_block_group_reservations() and
btrfs_wait_ordered_roots() for a data block group. And, for a metadata
block group, the comparison of alloc_offset vs meta_write_pointer mostly
ensures IOs for the allocated region already sent. However, there still
can be a little time frame where the IOs are sent but not yet completed.

Introduce wait_eb_writebacks() to ensure such IOs are completed for a
metadata block group. It walks the buffer_radix to find extent buffers in
the block group and calls wait_on_extent_buffer_writeback() on them.

Fixes: afba2bc036 ("btrfs: zoned: implement active zone tracking")
CC: stable@vger.kernel.org # 5.19+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Naohiro Aota 2022-09-09 15:59:55 +09:00 committed by David Sterba
parent a362bb864b
commit 2dd7e7bc02

View File

@ -1918,10 +1918,44 @@ out_unlock:
return ret;
}
static void wait_eb_writebacks(struct btrfs_block_group *block_group)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
const u64 end = block_group->start + block_group->length;
struct radix_tree_iter iter;
struct extent_buffer *eb;
void __rcu **slot;
rcu_read_lock();
radix_tree_for_each_slot(slot, &fs_info->buffer_radix, &iter,
block_group->start >> fs_info->sectorsize_bits) {
eb = radix_tree_deref_slot(slot);
if (!eb)
continue;
if (radix_tree_deref_retry(eb)) {
slot = radix_tree_iter_retry(&iter);
continue;
}
if (eb->start < block_group->start)
continue;
if (eb->start >= end)
break;
slot = radix_tree_iter_resume(slot, &iter);
rcu_read_unlock();
wait_on_extent_buffer_writeback(eb);
rcu_read_lock();
}
rcu_read_unlock();
}
static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_written)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct map_lookup *map;
const bool is_metadata = (block_group->flags &
(BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM));
int ret = 0;
int i;
@ -1932,8 +1966,7 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
}
/* Check if we have unwritten allocated space */
if ((block_group->flags &
(BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_SYSTEM)) &&
if (is_metadata &&
block_group->start + block_group->alloc_offset > block_group->meta_write_pointer) {
spin_unlock(&block_group->lock);
return -EAGAIN;
@ -1958,6 +1991,9 @@ static int do_zone_finish(struct btrfs_block_group *block_group, bool fully_writ
/* No need to wait for NOCOW writers. Zoned mode does not allow that */
btrfs_wait_ordered_roots(fs_info, U64_MAX, block_group->start,
block_group->length);
/* Wait for extent buffers to be written. */
if (is_metadata)
wait_eb_writebacks(block_group);
spin_lock(&block_group->lock);