linux/fs/btrfs/space-info.h
Nikolay Borisov db161806dc btrfs: account ticket size at add/delete time
Instead of iterating all pending tickets on the normal/priority list to
sum their total size the cost can be amortized across ticket addition/
removal. This turns O(n) + O(m) (where n is the size of the normal list
and m of the priority list) into O(1). This will mostly have effect in
workloads that experience heavy flushing.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:55 +01:00

153 lines
4.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BTRFS_SPACE_INFO_H
#define BTRFS_SPACE_INFO_H
struct btrfs_space_info {
spinlock_t lock;
u64 total_bytes; /* total bytes in the space,
this doesn't take mirrors into account */
u64 bytes_used; /* total bytes used,
this doesn't take mirrors into account */
u64 bytes_pinned; /* total bytes pinned, will be freed when the
transaction finishes */
u64 bytes_reserved; /* total bytes the allocator has reserved for
current allocations */
u64 bytes_may_use; /* number of bytes that may be used for
delalloc/allocations */
u64 bytes_readonly; /* total bytes that are read only */
u64 max_extent_size; /* This will hold the maximum extent size of
the space info if we had an ENOSPC in the
allocator. */
unsigned int full:1; /* indicates that we cannot allocate any more
chunks for this space */
unsigned int chunk_alloc:1; /* set if we are allocating a chunk */
unsigned int flush:1; /* set if we are trying to make space */
unsigned int force_alloc; /* set if we need to force a chunk
alloc for this space */
u64 disk_used; /* total bytes used on disk */
u64 disk_total; /* total bytes on disk, takes mirrors into
account */
u64 flags;
/*
* bytes_pinned is kept in line with what is actually pinned, as in
* we've called update_block_group and dropped the bytes_used counter
* and increased the bytes_pinned counter. However this means that
* bytes_pinned does not reflect the bytes that will be pinned once the
* delayed refs are flushed, so this counter is inc'ed every time we
* call btrfs_free_extent so it is a realtime count of what will be
* freed once the transaction is committed. It will be zeroed every
* time the transaction commits.
*/
struct percpu_counter total_bytes_pinned;
struct list_head list;
/* Protected by the spinlock 'lock'. */
struct list_head ro_bgs;
struct list_head priority_tickets;
struct list_head tickets;
/*
* Size of space that needs to be reclaimed in order to satisfy pending
* tickets
*/
u64 reclaim_size;
/*
* tickets_id just indicates the next ticket will be handled, so note
* it's not stored per ticket.
*/
u64 tickets_id;
struct rw_semaphore groups_sem;
/* for block groups in our same type */
struct list_head block_groups[BTRFS_NR_RAID_TYPES];
struct kobject kobj;
struct kobject *block_group_kobjs[BTRFS_NR_RAID_TYPES];
};
struct reserve_ticket {
u64 bytes;
int error;
struct list_head list;
wait_queue_head_t wait;
};
static inline bool btrfs_mixed_space_info(struct btrfs_space_info *space_info)
{
return ((space_info->flags & BTRFS_BLOCK_GROUP_METADATA) &&
(space_info->flags & BTRFS_BLOCK_GROUP_DATA));
}
/*
*
* Declare a helper function to detect underflow of various space info members
*/
#define DECLARE_SPACE_INFO_UPDATE(name, trace_name) \
static inline void \
btrfs_space_info_update_##name(struct btrfs_fs_info *fs_info, \
struct btrfs_space_info *sinfo, \
s64 bytes) \
{ \
const u64 abs_bytes = (bytes < 0) ? -bytes : bytes; \
lockdep_assert_held(&sinfo->lock); \
trace_update_##name(fs_info, sinfo, sinfo->name, bytes); \
trace_btrfs_space_reservation(fs_info, trace_name, \
sinfo->flags, abs_bytes, \
bytes > 0); \
if (bytes < 0 && sinfo->name < -bytes) { \
WARN_ON(1); \
sinfo->name = 0; \
return; \
} \
sinfo->name += bytes; \
}
DECLARE_SPACE_INFO_UPDATE(bytes_may_use, "space_info");
DECLARE_SPACE_INFO_UPDATE(bytes_pinned, "pinned");
int btrfs_init_space_info(struct btrfs_fs_info *fs_info);
void btrfs_update_space_info(struct btrfs_fs_info *info, u64 flags,
u64 total_bytes, u64 bytes_used,
u64 bytes_readonly,
struct btrfs_space_info **space_info);
struct btrfs_space_info *btrfs_find_space_info(struct btrfs_fs_info *info,
u64 flags);
u64 __pure btrfs_space_info_used(struct btrfs_space_info *s_info,
bool may_use_included);
void btrfs_clear_space_info_full(struct btrfs_fs_info *info);
void btrfs_dump_space_info(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *info, u64 bytes,
int dump_block_groups);
int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
struct btrfs_block_rsv *block_rsv,
u64 orig_bytes,
enum btrfs_reserve_flush_enum flush);
void btrfs_try_granting_tickets(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info);
int btrfs_can_overcommit(struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info, u64 bytes,
enum btrfs_reserve_flush_enum flush);
static inline void btrfs_space_info_free_bytes_may_use(
struct btrfs_fs_info *fs_info,
struct btrfs_space_info *space_info,
u64 num_bytes)
{
spin_lock(&space_info->lock);
btrfs_space_info_update_bytes_may_use(fs_info, space_info, -num_bytes);
btrfs_try_granting_tickets(fs_info, space_info);
spin_unlock(&space_info->lock);
}
#endif /* BTRFS_SPACE_INFO_H */