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 btrfs 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: Josef Bacik <[email protected]> Signed-off-by: Johannes Thumshirn <[email protected]> Signed-off-by: Naohiro Aota <[email protected]> --- fs/btrfs/block-group.c | 2 ++ fs/btrfs/ctree.h | 2 ++ fs/btrfs/disk-io.c | 1 + fs/btrfs/extent-tree.c | 75 +++++++++++++++++++++++++++++++++++++++--- fs/btrfs/zoned.h | 14 ++++++++ 5 files changed, 90 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c index f5e9f560ce6d..5064be59dac5 100644 --- a/fs/btrfs/block-group.c +++ b/fs/btrfs/block-group.c @@ -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; diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1bb4f767966a..6f4b493625ef 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d2fa92526b3b..84c6650d5ef7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -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); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index e2b2abc42295..f8e8c17e5624 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -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); diff --git a/fs/btrfs/zoned.h b/fs/btrfs/zoned.h index 932ad9bc0de6..61e969652fe1 100644 --- a/fs/btrfs/zoned.h +++ b/fs/btrfs/zoned.h @@ -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 -- 2.30.0