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-rw-r--r--fs/btrfs/ctree.h1
-rw-r--r--fs/btrfs/extent-tree.c25
-rw-r--r--fs/btrfs/transaction.c42
3 files changed, 40 insertions, 28 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 5e628dbce111..2aa3d882aede 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2610,7 +2610,6 @@ int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info,
u64 start, u64 len, int delalloc);
int btrfs_pin_reserved_extent(struct btrfs_trans_handle *trans, u64 start,
u64 len);
-void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info);
int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans);
int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
struct btrfs_ref *generic_ref);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 0345f9d97964..27523e6b6c2d 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2708,31 +2708,6 @@ btrfs_inc_block_group_reservations(struct btrfs_block_group *bg)
atomic_inc(&bg->reservations);
}
-void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
-{
- struct btrfs_caching_control *next;
- struct btrfs_caching_control *caching_ctl;
- struct btrfs_block_group *cache;
-
- down_write(&fs_info->commit_root_sem);
-
- list_for_each_entry_safe(caching_ctl, next,
- &fs_info->caching_block_groups, list) {
- cache = caching_ctl->block_group;
- if (btrfs_block_group_done(cache)) {
- cache->last_byte_to_unpin = (u64)-1;
- list_del_init(&caching_ctl->list);
- btrfs_put_caching_control(caching_ctl);
- } else {
- cache->last_byte_to_unpin = caching_ctl->progress;
- }
- }
-
- up_write(&fs_info->commit_root_sem);
-
- btrfs_update_global_block_rsv(fs_info);
-}
-
/*
* Returns the free cluster for the given space info and sets empty_cluster to
* what it should be based on the mount options.
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 931bef8cdd4c..89597ea57115 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -155,6 +155,7 @@ static noinline void switch_commit_roots(struct btrfs_trans_handle *trans)
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_root *root, *tmp;
+ struct btrfs_caching_control *caching_ctl, *next;
down_write(&fs_info->commit_root_sem);
list_for_each_entry_safe(root, tmp, &cur_trans->switch_commits,
@@ -180,6 +181,45 @@ static noinline void switch_commit_roots(struct btrfs_trans_handle *trans)
spin_lock(&cur_trans->dropped_roots_lock);
}
spin_unlock(&cur_trans->dropped_roots_lock);
+
+ /*
+ * We have to update the last_byte_to_unpin under the commit_root_sem,
+ * at the same time we swap out the commit roots.
+ *
+ * This is because we must have a real view of the last spot the caching
+ * kthreads were while caching. Consider the following views of the
+ * extent tree for a block group
+ *
+ * commit root
+ * +----+----+----+----+----+----+----+
+ * |\\\\| |\\\\|\\\\| |\\\\|\\\\|
+ * +----+----+----+----+----+----+----+
+ * 0 1 2 3 4 5 6 7
+ *
+ * new commit root
+ * +----+----+----+----+----+----+----+
+ * | | | |\\\\| | |\\\\|
+ * +----+----+----+----+----+----+----+
+ * 0 1 2 3 4 5 6 7
+ *
+ * If the cache_ctl->progress was at 3, then we are only allowed to
+ * unpin [0,1) and [2,3], because the caching thread has already
+ * processed those extents. We are not allowed to unpin [5,6), because
+ * the caching thread will re-start it's search from 3, and thus find
+ * the hole from [4,6) to add to the free space cache.
+ */
+ list_for_each_entry_safe(caching_ctl, next,
+ &fs_info->caching_block_groups, list) {
+ struct btrfs_block_group *cache = caching_ctl->block_group;
+
+ if (btrfs_block_group_done(cache)) {
+ cache->last_byte_to_unpin = (u64)-1;
+ list_del_init(&caching_ctl->list);
+ btrfs_put_caching_control(caching_ctl);
+ } else {
+ cache->last_byte_to_unpin = caching_ctl->progress;
+ }
+ }
up_write(&fs_info->commit_root_sem);
}
@@ -2254,8 +2294,6 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
goto unlock_tree_log;
}
- btrfs_prepare_extent_commit(fs_info);
-
cur_trans = fs_info->running_transaction;
btrfs_set_root_node(&fs_info->tree_root->root_item,