[PATCH 09/11] btrfs: Mark pinned log extents as excluded

Nikolay Borisov
2020-01-20T14:09:29Z

In preparation to making pinned extents per-transaction ensure that
log such extents are always excluded from caching. To achieve this in
addition to marking them via btrfs_pin_extent_for_log_replay they also
need to be marked with btrfs_add_excluded_extent to prevent log tree
extent buffer being loaded by the free space caching thread. That's
required since log treeblocks are not recorded in the extent tree, hence
they always look free.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
fs/btrfs/extent-tree.c | 8 ++++++++
fs/btrfs/tree-log.c | 2 +-
2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 7dcf9217a622..d680f2ac336b 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2634,6 +2634,8 @@ int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
struct btrfs_block_group *cache;
int ret;

+ btrfs_add_excluded_extent(trans->fs_info, bytenr, num_bytes);
+
cache = btrfs_lookup_block_group(trans->fs_info, bytenr);
if (!cache)
return -EINVAL;
@@ -2920,6 +2922,12 @@ 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,
+ 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/tree-log.c b/fs/btrfs/tree-log.c
index b535d409a728..f89de24838d5 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2994,7 +2994,7 @@ static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
mutex_unlock(&root->log_mutex);
}

-/*
+/*
* Invoked in log mutex context, or be sure there is no other task which
* can access the list.
*/
--
2.17.1