On 14.09.23 11:25, Qu Wenruo wrote:
+static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
+ int num_stripes,
+ struct btrfs_io_context *bioc)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_key stripe_key;
+ struct btrfs_root *stripe_root = btrfs_stripe_tree_root(fs_info);
+ u8 encoding = btrfs_bg_type_to_raid_encoding(bioc->map_type);
+ struct btrfs_stripe_extent *stripe_extent;
+ size_t item_size;
+ int ret;
+
+ item_size = struct_size(stripe_extent, strides, num_stripes);
I guess David has already pointed out this can be done at initialization
and make it const.
Will do
+
+ stripe_extent = kzalloc(item_size, GFP_NOFS);
+ if (!stripe_extent) {
+ btrfs_abort_transaction(trans, -ENOMEM);
+ btrfs_end_transaction(trans);
+ return -ENOMEM;
+ }
+
+ btrfs_set_stack_stripe_extent_encoding(stripe_extent, encoding);
+ for (int i = 0; i < num_stripes; i++) {
+ u64 devid = bioc->stripes[i].dev->devid;
+ u64 physical = bioc->stripes[i].physical;
+ u64 length = bioc->stripes[i].length;
+ struct btrfs_raid_stride *raid_stride =
+ &stripe_extent->strides[i];
+
+ if (length == 0)
+ length = bioc->size;
+
+ btrfs_set_stack_raid_stride_devid(raid_stride, devid);
+ btrfs_set_stack_raid_stride_physical(raid_stride, physical);
+ btrfs_set_stack_raid_stride_length(raid_stride, length);
+ }
+
+ stripe_key.objectid = bioc->logical;
+ stripe_key.type = BTRFS_RAID_STRIPE_KEY;
+ stripe_key.offset = bioc->size;
+
+ ret = btrfs_insert_item(trans, stripe_root, &stripe_key, stripe_extent,
+ item_size);
Have you tested in near-real-world on how continous the RST items could
be for RAID0/RAID10?
My concern here is, we may want to try our best to reduce the size of
RST, due to the 64K BTRFS_STRIPE_LEN.
There are two things I can do for it. First is trying to merge contiguus
RST items
and second make BTRFS_STRIPE_LEN a mkfs time constant instead
of a compile time constant.
But both can be done in a second step.
+ switch (map_type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
+ case BTRFS_BLOCK_GROUP_DUP:
+ case BTRFS_BLOCK_GROUP_RAID1:
+ case BTRFS_BLOCK_GROUP_RAID1C3:
+ case BTRFS_BLOCK_GROUP_RAID1C4:
+ ret = btrfs_insert_mirrored_raid_extents(trans, ordered_extent,
+ map_type);
+ break;
+ case BTRFS_BLOCK_GROUP_RAID0:
+ ret = btrfs_insert_striped_raid_extents(trans, ordered_extent,
+ map_type);
+ break;
+ case BTRFS_BLOCK_GROUP_RAID10:
+ ret = btrfs_insert_striped_mirrored_raid_extents(trans, ordered_extent, map_type);
+ break;
+ default:
+ ret = -EINVAL;
Maybe we want to be a little more noisy?
OK.