Btrfs: add basic infrastructure for selective balancing
This allows to have a separate set of filters for each chunk type
(data,meta,sys). The code however is generic and switch on chunk type
is only done once.
This commit also adds a type filter: it allows to balance for example
meta and system chunks w/o touching data ones.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9fc06e6b..91bbf6e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2102,6 +2102,30 @@
kfree(bctl);
}
+static int should_balance_chunk(struct btrfs_root *root,
+ struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk, u64 chunk_offset)
+{
+ struct btrfs_balance_control *bctl = root->fs_info->balance_ctl;
+ struct btrfs_balance_args *bargs = NULL;
+ u64 chunk_type = btrfs_chunk_type(leaf, chunk);
+
+ /* type filter */
+ if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) &
+ (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) {
+ return 0;
+ }
+
+ if (chunk_type & BTRFS_BLOCK_GROUP_DATA)
+ bargs = &bctl->data;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM)
+ bargs = &bctl->sys;
+ else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA)
+ bargs = &bctl->meta;
+
+ return 1;
+}
+
static u64 div_factor(u64 num, int factor)
{
if (factor == 10)
@@ -2119,10 +2143,13 @@
struct btrfs_device *device;
u64 old_size;
u64 size_to_free;
+ struct btrfs_chunk *chunk;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_trans_handle *trans;
+ struct extent_buffer *leaf;
+ int slot;
int ret;
int enospc_errors = 0;
@@ -2179,8 +2206,10 @@
break;
}
- btrfs_item_key_to_cpu(path->nodes[0], &found_key,
- path->slots[0]);
+ leaf = path->nodes[0];
+ slot = path->slots[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, slot);
+
if (found_key.objectid != key.objectid)
break;
@@ -2188,7 +2217,14 @@
if (found_key.offset == 0)
break;
+ chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
+
+ ret = should_balance_chunk(chunk_root, leaf, chunk,
+ found_key.offset);
btrfs_release_path(path);
+ if (!ret)
+ goto loop;
+
ret = btrfs_relocate_chunk(chunk_root,
chunk_root->root_key.objectid,
found_key.objectid,
@@ -2197,6 +2233,7 @@
goto error;
if (ret == -ENOSPC)
enospc_errors++;
+loop:
key.offset = found_key.offset - 1;
}
@@ -2227,6 +2264,7 @@
struct btrfs_ioctl_balance_args *bargs)
{
struct btrfs_fs_info *fs_info = bctl->fs_info;
+ u64 allowed;
int ret;
if (btrfs_fs_closing(fs_info)) {
@@ -2234,6 +2272,23 @@
goto out;
}
+ /*
+ * In case of mixed groups both data and meta should be picked,
+ * and identical options should be given for both of them.
+ */
+ allowed = btrfs_super_incompat_flags(fs_info->super_copy);
+ if ((allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) &&
+ (bctl->flags & (BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA))) {
+ if (!(bctl->flags & BTRFS_BALANCE_DATA) ||
+ !(bctl->flags & BTRFS_BALANCE_METADATA) ||
+ memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) {
+ printk(KERN_ERR "btrfs: with mixed groups data and "
+ "metadata balance options must be the same\n");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
set_balance_control(bctl);
mutex_unlock(&fs_info->balance_mutex);