[PATCH v2] btrfs: Use btrfs_transaction::pinned_extents

Nikolay Borisov
2020-01-24T10:35:48Z

This commit flips the switch to start tracking/processing pinned
extents on a per-transaction basis. It mostly replaces all references
from btrfs_fs_info::(pinned_extents|freed_extents[]) to
btrfs_transaction::pinned_extents. Two notable modifications that
warrant explicit mention are changing clean_pinned_extents to get a
reference to the previously running transaction. The other one is
removal of call to btrfs_destroy_pinned_extent since transactions are
going to be cleaned in btrfs_cleanup_one_transaction.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---

V2:
* Properly release transaction in clean_pinned_extents [Josef]
* Only check for EXTENT_UPTODATE in add_new_free_space [Josef]

fs/btrfs/block-group.c | 43 +++++++++++++++++++++++-------------
fs/btrfs/ctree.h | 4 ++--
fs/btrfs/disk-io.c | 30 +++++--------------------
fs/btrfs/extent-io-tree.h | 3 +--
fs/btrfs/extent-tree.c | 31 +++++++-------------------
fs/btrfs/free-space-cache.c | 2 +-
fs/btrfs/tests/btrfs-tests.c | 7 ++----
fs/btrfs/transaction.c | 1 +
fs/btrfs/transaction.h | 1 +
include/trace/events/btrfs.h | 3 +--
10 files changed, 50 insertions(+), 75 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 48bb9e08f2e8..91054c32d88a 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -460,10 +460,9 @@ u64 add_new_free_space(struct btrfs_block_group *block_group, u64 start, u64 end
int ret;

while (start < end) {
- ret = find_first_extent_bit(info->pinned_extents, start,
+ ret = find_first_extent_bit(&info->excluded_extents, start,
&extent_start, &extent_end,
- EXTENT_DIRTY | EXTENT_UPTODATE,
- NULL);
+ EXTENT_UPTODATE, NULL);
if (ret)
break;

@@ -1233,32 +1232,46 @@ static int inc_block_group_ro(struct btrfs_block_group *cache, int force)
return ret;
}

-static bool clean_pinned_extents(struct btrfs_block_group *bg)
+static bool clean_pinned_extents(struct btrfs_trans_handle *trans,
+ struct btrfs_block_group *bg)
{
struct btrfs_fs_info *fs_info = bg->fs_info;
+ struct btrfs_transaction *prev_trans = NULL;
u64 start = bg->start;
u64 end = start + bg->length - 1;
int ret;

+ spin_lock(&fs_info->trans_lock);
+ if (trans->transaction->list.prev != &fs_info->trans_list) {
+ prev_trans = list_entry(trans->transaction->list.prev,
+ struct btrfs_transaction, list);
+ refcount_inc(&prev_trans->use_count);
+ }
+ spin_unlock(&fs_info->trans_lock);
+
/*
* Hold the unused_bg_unpin_mutex lock to avoid racing with
* btrfs_finish_extent_commit(). If we are at transaction N,
* another task might be running finish_extent_commit() for the
* previous transaction N - 1, and have seen a range belonging
- * to the block group in freed_extents[] before we were able to
- * clear the whole block group range from freed_extents[]. This
+ * to the block group in pinned_extents before we were able to
+ * clear the whole block group range from pinned_extents. This
* means that task can lookup for the block group after we
- * unpinned it from freed_extents[] and removed it, leading to
+ * unpinned it from pinned_extents[] and removed it, leading to
* a BUG_ON() at unpin_extent_range().
*/
mutex_lock(&fs_info->unused_bg_unpin_mutex);
- ret = clear_extent_bits(&fs_info->freed_extents[0], start, end,
- EXTENT_DIRTY);
- if (ret)
- goto failure;
+ if (prev_trans) {
+ ret = clear_extent_bits(&prev_trans->pinned_extents, start, end,
+ EXTENT_DIRTY);
+ if (ret)
+ goto failure;
+ }
+
+ btrfs_put_transaction(prev_trans);

- ret = clear_extent_bits(&fs_info->freed_extents[1], start, end,
- EXTENT_DIRTY);
+ ret = clear_extent_bits(&trans->transaction->pinned_extents, start, end,
+ EXTENT_DIRTY);
if (ret)
goto failure;
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
@@ -1367,7 +1380,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
* We could have pending pinned extents for this block group,
* just delete them, we don't care about them anymore.
*/
- if (!clean_pinned_extents(block_group))
+ if (!clean_pinned_extents(trans, block_group))
goto end_trans;

/*
@@ -2877,7 +2890,7 @@ int btrfs_update_block_group(struct btrfs_trans_handle *trans,
&cache->space_info->total_bytes_pinned,
num_bytes,
BTRFS_TOTAL_BYTES_PINNED_BATCH);
- set_extent_dirty(info->pinned_extents,
+ set_extent_dirty(&trans->transaction->pinned_extents,
bytenr, bytenr + num_bytes - 1,
GFP_NOFS | __GFP_NOFAIL);
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c6ce8c047814..a84072fbb4e7 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -596,8 +596,8 @@ struct btrfs_fs_info {
/* keep track of unallocated space */
atomic64_t free_chunk_space;

- struct extent_io_tree freed_extents[2];
- struct extent_io_tree *pinned_extents;
+ /* Tracks ranges which used by log trees blocks/logged data extents */
+ struct extent_io_tree excluded_extents;

/* logical->physical extent mapping */
struct extent_map_tree mapping_tree;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9209c7b0997c..3cb786463eb2 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2021,10 +2021,8 @@ void btrfs_free_fs_roots(struct btrfs_fs_info *fs_info)
btrfs_drop_and_free_fs_root(fs_info, gang[i]);
}

- if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
+ if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
btrfs_free_log_root_tree(NULL, fs_info);
- btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
- }
}

static void btrfs_init_scrub(struct btrfs_fs_info *fs_info)
@@ -2779,11 +2777,8 @@ int __cold open_ctree(struct super_block *sb,
fs_info->block_group_cache_tree = RB_ROOT;
fs_info->first_logical_byte = (u64)-1;

- extent_io_tree_init(fs_info, &fs_info->freed_extents[0],
- IO_TREE_FS_INFO_FREED_EXTENTS0, NULL);
- extent_io_tree_init(fs_info, &fs_info->freed_extents[1],
- IO_TREE_FS_INFO_FREED_EXTENTS1, NULL);
- fs_info->pinned_extents = &fs_info->freed_extents[0];
+ extent_io_tree_init(fs_info, &fs_info->excluded_extents,
+ IO_TREE_FS_INFO_EXCLUDED_EXTENTS, NULL);
set_bit(BTRFS_FS_BARRIER, &fs_info->flags);

mutex_init(&fs_info->ordered_operations_mutex);
@@ -4384,16 +4379,12 @@ static int btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
}

static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
- struct extent_io_tree *pinned_extents)
+ struct extent_io_tree *unpin)
{
- struct extent_io_tree *unpin;
u64 start;
u64 end;
int ret;
- bool loop = true;

- unpin = pinned_extents;
-again:
while (1) {
struct extent_state *cached_state = NULL;

@@ -4418,15 +4409,6 @@ static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
cond_resched();
}

- if (loop) {
- if (unpin == &fs_info->freed_extents[0])
- unpin = &fs_info->freed_extents[1];
- else
- unpin = &fs_info->freed_extents[0];
- loop = false;
- goto again;
- }
-
return 0;
}

@@ -4518,8 +4500,7 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,

btrfs_destroy_marked_extents(fs_info, &cur_trans->dirty_pages,
EXTENT_DIRTY);
- btrfs_destroy_pinned_extent(fs_info,
- fs_info->pinned_extents);
+ btrfs_destroy_pinned_extent(fs_info, &cur_trans->pinned_extents);

cur_trans->state =TRANS_STATE_COMPLETED;
wake_up(&cur_trans->commit_wait);
@@ -4571,7 +4552,6 @@ static int btrfs_cleanup_transaction(struct btrfs_fs_info *fs_info)
btrfs_destroy_all_ordered_extents(fs_info);
btrfs_destroy_delayed_inodes(fs_info);
btrfs_assert_delayed_root_empty(fs_info);
- btrfs_destroy_pinned_extent(fs_info, fs_info->pinned_extents);
btrfs_destroy_all_delalloc_inodes(fs_info);
mutex_unlock(&fs_info->transaction_kthread_mutex);

diff --git a/fs/btrfs/extent-io-tree.h b/fs/btrfs/extent-io-tree.h
index a3febe746c79..02c2e4e711bf 100644
--- a/fs/btrfs/extent-io-tree.h
+++ b/fs/btrfs/extent-io-tree.h
@@ -36,8 +36,7 @@ struct io_failure_record;
#define CHUNK_TRIMMED EXTENT_DEFRAG

enum {
- IO_TREE_FS_INFO_FREED_EXTENTS0,
- IO_TREE_FS_INFO_FREED_EXTENTS1,
+ IO_TREE_FS_INFO_EXCLUDED_EXTENTS,
IO_TREE_INODE_IO,
IO_TREE_INODE_IO_FAILURE,
IO_TREE_RELOC_BLOCKS,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d680f2ac336b..f7b89ab921e1 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -64,10 +64,8 @@ int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info,
u64 start, u64 num_bytes)
{
u64 end = start + num_bytes - 1;
- set_extent_bits(&fs_info->freed_extents[0],
- start, end, EXTENT_UPTODATE);
- set_extent_bits(&fs_info->freed_extents[1],
- start, end, EXTENT_UPTODATE);
+ set_extent_bits(&fs_info->excluded_extents, start, end,
+ EXTENT_UPTODATE);
return 0;
}

@@ -79,10 +77,8 @@ void btrfs_free_excluded_extents(struct btrfs_block_group *cache)
start = cache->start;
end = start + cache->length - 1;

- clear_extent_bits(&fs_info->freed_extents[0],
- start, end, EXTENT_UPTODATE);
- clear_extent_bits(&fs_info->freed_extents[1],
- start, end, EXTENT_UPTODATE);
+ clear_extent_bits(&fs_info->excluded_extents, start, end,
+ EXTENT_UPTODATE);
}

static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
@@ -2606,7 +2602,7 @@ static int pin_down_extent(struct btrfs_trans_handle *trans,

percpu_counter_add_batch(&cache->space_info->total_bytes_pinned,
num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH);
- set_extent_dirty(fs_info->pinned_extents, bytenr,
+ set_extent_dirty(&trans->transaction->pinned_extents, bytenr,
bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL);
return 0;
}
@@ -2762,11 +2758,6 @@ void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
}
}

- if (fs_info->pinned_extents == &fs_info->freed_extents[0])
- fs_info->pinned_extents = &fs_info->freed_extents[1];
- else
- fs_info->pinned_extents = &fs_info->freed_extents[0];
-
up_write(&fs_info->commit_root_sem);

btrfs_update_global_block_rsv(fs_info);
@@ -2907,10 +2898,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
u64 end;
int ret;

- if (fs_info->pinned_extents == &fs_info->freed_extents[0])
- unpin = &fs_info->freed_extents[1];
- else
- unpin = &fs_info->freed_extents[0];
+ unpin = &trans->transaction->pinned_extents;

while (!trans->aborted) {
struct extent_state *cached_state = NULL;
@@ -2922,12 +2910,9 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans)
mutex_unlock(&fs_info->unused_bg_unpin_mutex);
break;
}
- if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
- clear_extent_bits(&fs_info->freed_extents[0], start,
+ if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
+ clear_extent_bits(&fs_info->excluded_extents, start,
end, EXTENT_UPTODATE);
- clear_extent_bits(&fs_info->freed_extents[1], start,
- end, EXTENT_UPTODATE);
- }

if (btrfs_test_opt(fs_info, DISCARD_SYNC))
ret = btrfs_discard_extent(fs_info, start,
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 9d6372139547..bd9c4b5da549 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1086,7 +1086,7 @@ static noinline_for_stack int write_pinned_extent_entries(
* We shouldn't have switched the pinned extents yet so this is the
* right one
*/
- unpin = block_group->fs_info->pinned_extents;
+ unpin = &trans->transaction->pinned_extents;

start = block_group->start;

diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index c12b91ff5f56..2f7514068c3f 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -156,12 +156,9 @@ struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize)
INIT_LIST_HEAD(&fs_info->fs_devices->devices);
INIT_RADIX_TREE(&fs_info->buffer_radix, GFP_ATOMIC);
INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
- extent_io_tree_init(fs_info, &fs_info->freed_extents[0],
- IO_TREE_FS_INFO_FREED_EXTENTS0, NULL);
- extent_io_tree_init(fs_info, &fs_info->freed_extents[1],
- IO_TREE_FS_INFO_FREED_EXTENTS1, NULL);
+ extent_io_tree_init(fs_info, &fs_info->excluded_extents,
+ IO_TREE_FS_INFO_EXCLUDED_EXTENTS, NULL);
extent_map_tree_init(&fs_info->mapping_tree);
- fs_info->pinned_extents = &fs_info->freed_extents[0];
set_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);

test_mnt->mnt_sb->s_fs_info = fs_info;
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 55d8fd68775a..4b9091582ec4 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -334,6 +334,7 @@ static noinline int join_transaction(struct btrfs_fs_info *fs_info,
list_add_tail(&cur_trans->list, &fs_info->trans_list);
extent_io_tree_init(fs_info, &cur_trans->dirty_pages,
IO_TREE_TRANS_DIRTY_PAGES, fs_info->btree_inode);
+ extent_io_tree_init(fs_info, &cur_trans->pinned_extents, 0, NULL);
fs_info->generation++;
cur_trans->transid = fs_info->generation;
fs_info->running_transaction = cur_trans;
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 49f7196368f5..2a046a0155c1 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -71,6 +71,7 @@ struct btrfs_transaction {
*/
struct list_head io_bgs;
struct list_head dropped_roots;
+ struct extent_io_tree pinned_extents;

/*
* we need to make sure block group deletion doesn't race with
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index 17088a112ed0..f4fa3e15297d 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -81,8 +81,7 @@ TRACE_DEFINE_ENUM(COMMIT_TRANS);

#define show_extent_io_tree_owner(owner) \
__print_symbolic(owner, \
- { IO_TREE_FS_INFO_FREED_EXTENTS0, "FREED_EXTENTS0" }, \
- { IO_TREE_FS_INFO_FREED_EXTENTS1, "FREED_EXTENTS1" }, \
+ { IO_TREE_FS_INFO_EXCLUDED_EXTENTS, "EXCLUDED_EXTENTS" }, \
{ IO_TREE_INODE_IO, "INODE_IO" }, \
{ IO_TREE_INODE_IO_FAILURE, "INODE_IO_FAILURE" }, \
{ IO_TREE_RELOC_BLOCKS, "RELOC_BLOCKS" }, \
--
2.17.1