Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: be more polite in the async caching threads
Btrfs: preserve commit_root for async caching
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 215ef8c..837435c 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -825,6 +825,7 @@
struct mutex drop_mutex;
struct mutex volume_mutex;
struct mutex tree_reloc_mutex;
+ struct rw_semaphore extent_commit_sem;
/*
* this protects the ordered operations list only while we are
@@ -959,9 +960,6 @@
/* the node lock is held while changing the node pointer */
spinlock_t node_lock;
- /* taken when updating the commit root */
- struct rw_semaphore commit_root_sem;
-
struct extent_buffer *commit_root;
struct btrfs_root *log_root;
struct btrfs_root *reloc_root;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 7dcaa81..e83be2e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -909,7 +909,6 @@
spin_lock_init(&root->inode_lock);
mutex_init(&root->objectid_mutex);
mutex_init(&root->log_mutex);
- init_rwsem(&root->commit_root_sem);
init_waitqueue_head(&root->log_writer_wait);
init_waitqueue_head(&root->log_commit_wait[0]);
init_waitqueue_head(&root->log_commit_wait[1]);
@@ -1640,6 +1639,7 @@
mutex_init(&fs_info->cleaner_mutex);
mutex_init(&fs_info->volume_mutex);
mutex_init(&fs_info->tree_reloc_mutex);
+ init_rwsem(&fs_info->extent_commit_sem);
btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fadf69a..dc84dae 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -267,7 +267,7 @@
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
again:
/* need to make sure the commit_root doesn't disappear */
- down_read(&fs_info->extent_root->commit_root_sem);
+ down_read(&fs_info->extent_commit_sem);
/*
* We don't want to deadlock with somebody trying to allocate a new
@@ -302,10 +302,11 @@
else if (ret)
break;
- if (need_resched()) {
+ if (need_resched() ||
+ btrfs_transaction_in_commit(fs_info)) {
btrfs_release_path(fs_info->extent_root, path);
- up_read(&fs_info->extent_root->commit_root_sem);
- cond_resched();
+ up_read(&fs_info->extent_commit_sem);
+ schedule_timeout(1);
goto again;
}
@@ -345,7 +346,7 @@
err:
btrfs_free_path(path);
- up_read(&fs_info->extent_root->commit_root_sem);
+ up_read(&fs_info->extent_commit_sem);
atomic_dec(&block_group->space_info->caching_threads);
wake_up(&block_group->caching_q);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index e51d2bc..cdbb502 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -42,10 +42,8 @@
static noinline void switch_commit_root(struct btrfs_root *root)
{
- down_write(&root->commit_root_sem);
free_extent_buffer(root->commit_root);
root->commit_root = btrfs_root_node(root);
- up_write(&root->commit_root_sem);
}
/*
@@ -466,7 +464,10 @@
ret = btrfs_write_dirty_block_groups(trans, root);
BUG_ON(ret);
}
- switch_commit_root(root);
+
+ if (root != root->fs_info->extent_root)
+ switch_commit_root(root);
+
return 0;
}
@@ -499,6 +500,11 @@
update_cowonly_root(trans, root);
}
+
+ down_write(&fs_info->extent_commit_sem);
+ switch_commit_root(fs_info->extent_root);
+ up_write(&fs_info->extent_commit_sem);
+
return 0;
}
@@ -851,6 +857,16 @@
super->root_level = root_item->level;
}
+int btrfs_transaction_in_commit(struct btrfs_fs_info *info)
+{
+ int ret = 0;
+ spin_lock(&info->new_trans_lock);
+ if (info->running_transaction)
+ ret = info->running_transaction->in_commit;
+ spin_unlock(&info->new_trans_lock);
+ return ret;
+}
+
int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
{
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 961c3ee..663c674 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -107,4 +107,5 @@
struct btrfs_root *root);
int btrfs_write_and_wait_marked_extents(struct btrfs_root *root,
struct extent_io_tree *dirty_pages);
+int btrfs_transaction_in_commit(struct btrfs_fs_info *info);
#endif
