btrfs: move basic block_group definitions to their own header
This is prep work for moving all of the block group cache code into its
own file.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
new file mode 100644
index 0000000..0547450
--- /dev/null
+++ b/fs/btrfs/block-group.h
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_BLOCK_GROUP_H
+#define BTRFS_BLOCK_GROUP_H
+
+enum btrfs_disk_cache_state {
+ BTRFS_DC_WRITTEN,
+ BTRFS_DC_ERROR,
+ BTRFS_DC_CLEAR,
+ BTRFS_DC_SETUP,
+};
+
+struct btrfs_caching_control {
+ struct list_head list;
+ struct mutex mutex;
+ wait_queue_head_t wait;
+ struct btrfs_work work;
+ struct btrfs_block_group_cache *block_group;
+ u64 progress;
+ refcount_t count;
+};
+
+/* Once caching_thread() finds this much free space, it will wake up waiters. */
+#define CACHING_CTL_WAKE_UP SZ_2M
+
+struct btrfs_block_group_cache {
+ struct btrfs_key key;
+ struct btrfs_block_group_item item;
+ struct btrfs_fs_info *fs_info;
+ struct inode *inode;
+ spinlock_t lock;
+ u64 pinned;
+ u64 reserved;
+ u64 delalloc_bytes;
+ u64 bytes_super;
+ u64 flags;
+ u64 cache_generation;
+
+ /*
+ * If the free space extent count exceeds this number, convert the block
+ * group to bitmaps.
+ */
+ u32 bitmap_high_thresh;
+
+ /*
+ * If the free space extent count drops below this number, convert the
+ * block group back to extents.
+ */
+ u32 bitmap_low_thresh;
+
+ /*
+ * It is just used for the delayed data space allocation because
+ * only the data space allocation and the relative metadata update
+ * can be done cross the transaction.
+ */
+ struct rw_semaphore data_rwsem;
+
+ /* For raid56, this is a full stripe, without parity */
+ unsigned long full_stripe_len;
+
+ unsigned int ro;
+ unsigned int iref:1;
+ unsigned int has_caching_ctl:1;
+ unsigned int removed:1;
+
+ int disk_cache_state;
+
+ /* Cache tracking stuff */
+ int cached;
+ struct btrfs_caching_control *caching_ctl;
+ u64 last_byte_to_unpin;
+
+ struct btrfs_space_info *space_info;
+
+ /* Free space cache stuff */
+ struct btrfs_free_space_ctl *free_space_ctl;
+
+ /* Block group cache stuff */
+ struct rb_node cache_node;
+
+ /* For block groups in the same raid type */
+ struct list_head list;
+
+ /* Usage count */
+ atomic_t count;
+
+ /*
+ * List of struct btrfs_free_clusters for this block group.
+ * Today it will only have one thing on it, but that may change
+ */
+ struct list_head cluster_list;
+
+ /* For delayed block group creation or deletion of empty block groups */
+ struct list_head bg_list;
+
+ /* For read-only block groups */
+ struct list_head ro_list;
+
+ atomic_t trimming;
+
+ /* For dirty block groups */
+ struct list_head dirty_list;
+ struct list_head io_list;
+
+ struct btrfs_io_ctl io_ctl;
+
+ /*
+ * Incremented when doing extent allocations and holding a read lock
+ * on the space_info's groups_sem semaphore.
+ * Decremented when an ordered extent that represents an IO against this
+ * block group's range is created (after it's added to its inode's
+ * root's list of ordered extents) or immediately after the allocation
+ * if it's a metadata extent or fallocate extent (for these cases we
+ * don't create ordered extents).
+ */
+ atomic_t reservations;
+
+ /*
+ * Incremented while holding the spinlock *lock* by a task checking if
+ * it can perform a nocow write (incremented if the value for the *ro*
+ * field is 0). Decremented by such tasks once they create an ordered
+ * extent or before that if some error happens before reaching that step.
+ * This is to prevent races between block group relocation and nocow
+ * writes through direct IO.
+ */
+ atomic_t nocow_writers;
+
+ /* Lock for free space tree operations. */
+ struct mutex free_space_lock;
+
+ /*
+ * Does the block group need to be added to the free space tree?
+ * Protected by free_space_lock.
+ */
+ int needs_free_space;
+
+ /* Record locked full stripes for RAID5/6 block group */
+ struct btrfs_full_stripe_locks_tree full_stripe_locks_root;
+};
+
+#ifdef CONFIG_BTRFS_DEBUG
+static inline int btrfs_should_fragment_free_space(
+ struct btrfs_block_group_cache *block_group)
+{
+ struct btrfs_fs_info *fs_info = block_group->fs_info;
+
+ return (btrfs_test_opt(fs_info, FRAGMENT_METADATA) &&
+ block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
+ (btrfs_test_opt(fs_info, FRAGMENT_DATA) &&
+ block_group->flags & BTRFS_BLOCK_GROUP_DATA);
+}
+#endif
+
+#endif /* BTRFS_BLOCK_GROUP_H */