Commit 40ab3be1 authored by Naohiro Aota's avatar Naohiro Aota Committed by David Sterba

btrfs: zoned: extend zoned allocator to use dedicated tree-log block group

This is the 1/3 patch to enable tree log on zoned filesystems.

The tree-log feature does not work on a zoned filesystem as is. Blocks for
a tree-log tree are allocated mixed with other metadata blocks and btrfs
writes and syncs the tree-log blocks to devices at the time of fsync(),
which has a different timing than a global transaction commit. As a
result, both writing tree-log blocks and writing other metadata blocks
become non-sequential writes that zoned filesystems must avoid.

Introduce a dedicated block group for tree-log blocks, so that tree-log
blocks and other metadata blocks can be separate write streams.  As a
result, each write stream can now be written to devices separately.
"fs_info->treelog_bg" tracks the dedicated block group and assigns
"treelog_bg" on-demand on tree-log block allocation time.

This commit extends the zoned block allocator to use the block group.
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Signed-off-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6ab6ebb7
......@@ -901,6 +901,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&cluster->refill_lock);
btrfs_clear_treelog_bg(block_group);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
......
......@@ -976,6 +976,8 @@ struct btrfs_fs_info {
/* Max size to emit ZONE_APPEND write command */
u64 max_zone_append_size;
struct mutex zoned_meta_io_lock;
spinlock_t treelog_bg_lock;
u64 treelog_bg;
#ifdef CONFIG_BTRFS_FS_REF_VERIFY
spinlock_t ref_verify_lock;
......
......@@ -2787,6 +2787,7 @@ void btrfs_init_fs_info(struct btrfs_fs_info *fs_info)
spin_lock_init(&fs_info->super_lock);
spin_lock_init(&fs_info->buffer_lock);
spin_lock_init(&fs_info->unused_bgs_lock);
spin_lock_init(&fs_info->treelog_bg_lock);
rwlock_init(&fs_info->tree_mod_log_lock);
mutex_init(&fs_info->unused_bg_unpin_mutex);
mutex_init(&fs_info->delete_unused_bgs_mutex);
......
......@@ -3497,6 +3497,9 @@ struct find_free_extent_ctl {
bool have_caching_bg;
bool orig_have_caching_bg;
/* Allocation is called for tree-log */
bool for_treelog;
/* RAID index, converted from flags */
int index;
......@@ -3725,6 +3728,22 @@ static int do_allocation_clustered(struct btrfs_block_group *block_group,
return find_free_extent_unclustered(block_group, ffe_ctl);
}
/*
* Tree-log block group locking
* ============================
*
* fs_info::treelog_bg_lock protects the fs_info::treelog_bg which
* indicates the starting address of a block group, which is reserved only
* for tree-log metadata.
*
* Lock nesting
* ============
*
* space_info::lock
* block_group::lock
* fs_info::treelog_bg_lock
*/
/*
* Simple allocator for sequential-only block group. It only allows sequential
* allocation. No need to play with trees. This function also reserves the
......@@ -3734,23 +3753,54 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
struct find_free_extent_ctl *ffe_ctl,
struct btrfs_block_group **bg_ret)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct btrfs_space_info *space_info = block_group->space_info;
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
u64 start = block_group->start;
u64 num_bytes = ffe_ctl->num_bytes;
u64 avail;
u64 bytenr = block_group->start;
u64 log_bytenr;
int ret = 0;
bool skip;
ASSERT(btrfs_is_zoned(block_group->fs_info));
/*
* Do not allow non-tree-log blocks in the dedicated tree-log block
* group, and vice versa.
*/
spin_lock(&fs_info->treelog_bg_lock);
log_bytenr = fs_info->treelog_bg;
skip = log_bytenr && ((ffe_ctl->for_treelog && bytenr != log_bytenr) ||
(!ffe_ctl->for_treelog && bytenr == log_bytenr));
spin_unlock(&fs_info->treelog_bg_lock);
if (skip)
return 1;
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
spin_lock(&fs_info->treelog_bg_lock);
ASSERT(!ffe_ctl->for_treelog ||
block_group->start == fs_info->treelog_bg ||
fs_info->treelog_bg == 0);
if (block_group->ro) {
ret = 1;
goto out;
}
/*
* Do not allow currently using block group to be tree-log dedicated
* block group.
*/
if (ffe_ctl->for_treelog && !fs_info->treelog_bg &&
(block_group->used || block_group->reserved)) {
ret = 1;
goto out;
}
avail = block_group->length - block_group->alloc_offset;
if (avail < num_bytes) {
if (ffe_ctl->max_extent_size < avail) {
......@@ -3765,6 +3815,9 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
goto out;
}
if (ffe_ctl->for_treelog && !fs_info->treelog_bg)
fs_info->treelog_bg = block_group->start;
ffe_ctl->found_offset = start + block_group->alloc_offset;
block_group->alloc_offset += num_bytes;
spin_lock(&ctl->tree_lock);
......@@ -3779,6 +3832,9 @@ static int do_allocation_zoned(struct btrfs_block_group *block_group,
ffe_ctl->search_start = ffe_ctl->found_offset;
out:
if (ret && ffe_ctl->for_treelog)
fs_info->treelog_bg = 0;
spin_unlock(&fs_info->treelog_bg_lock);
spin_unlock(&block_group->lock);
spin_unlock(&space_info->lock);
return ret;
......@@ -4028,7 +4084,12 @@ static int prepare_allocation(struct btrfs_fs_info *fs_info,
return prepare_allocation_clustered(fs_info, ffe_ctl,
space_info, ins);
case BTRFS_EXTENT_ALLOC_ZONED:
/* Nothing to do */
if (ffe_ctl->for_treelog) {
spin_lock(&fs_info->treelog_bg_lock);
if (fs_info->treelog_bg)
ffe_ctl->hint_byte = fs_info->treelog_bg;
spin_unlock(&fs_info->treelog_bg_lock);
}
return 0;
default:
BUG();
......@@ -4072,6 +4133,7 @@ static noinline int find_free_extent(struct btrfs_root *root,
struct find_free_extent_ctl ffe_ctl = {0};
struct btrfs_space_info *space_info;
bool full_search = false;
bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
WARN_ON(num_bytes < fs_info->sectorsize);
......@@ -4085,6 +4147,7 @@ static noinline int find_free_extent(struct btrfs_root *root,
ffe_ctl.orig_have_caching_bg = false;
ffe_ctl.found_offset = 0;
ffe_ctl.hint_byte = hint_byte_orig;
ffe_ctl.for_treelog = for_treelog;
ffe_ctl.policy = BTRFS_EXTENT_ALLOC_CLUSTERED;
/* For clustered allocation */
......@@ -4159,8 +4222,11 @@ static noinline int find_free_extent(struct btrfs_root *root,
struct btrfs_block_group *bg_ret;
/* If the block group is read-only, we can skip it entirely. */
if (unlikely(block_group->ro))
if (unlikely(block_group->ro)) {
if (for_treelog)
btrfs_clear_treelog_bg(block_group);
continue;
}
btrfs_grab_block_group(block_group, delalloc);
ffe_ctl.search_start = block_group->start;
......@@ -4346,6 +4412,7 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
bool final_tried = num_bytes == min_alloc_size;
u64 flags;
int ret;
bool for_treelog = (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
flags = get_alloc_profile_by_root(root, is_data);
again:
......@@ -4369,8 +4436,8 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes,
sinfo = btrfs_find_space_info(fs_info, flags);
btrfs_err(fs_info,
"allocation failed flags %llu, wanted %llu",
flags, num_bytes);
"allocation failed flags %llu, wanted %llu tree-log %d",
flags, num_bytes, for_treelog);
if (sinfo)
btrfs_dump_space_info(fs_info, sinfo,
num_bytes, 1);
......
......@@ -7,6 +7,7 @@
#include <linux/blkdev.h>
#include "volumes.h"
#include "disk-io.h"
#include "block-group.h"
struct btrfs_zoned_device_info {
/*
......@@ -290,4 +291,17 @@ static inline void btrfs_zoned_meta_io_unlock(struct btrfs_fs_info *fs_info)
mutex_unlock(&fs_info->zoned_meta_io_lock);
}
static inline void btrfs_clear_treelog_bg(struct btrfs_block_group *bg)
{
struct btrfs_fs_info *fs_info = bg->fs_info;
if (!btrfs_is_zoned(fs_info))
return;
spin_lock(&fs_info->treelog_bg_lock);
if (fs_info->treelog_bg == bg->start)
fs_info->treelog_bg = 0;
spin_unlock(&fs_info->treelog_bg_lock);
}
#endif
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