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 215ef8cae823ce53cf91e559ebfe7ed602eda214..837435ce84caa104dcb00ba9830df29a47e95923 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -825,6 +825,7 @@ struct btrfs_fs_info {
        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 @@ struct btrfs_root {
        /* 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 7dcaa8138864b455ea0314bcf78d17fe820c2f5d..e83be2e4602c256f959a2b9daf0c3da2b8e9bcab 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -909,7 +909,6 @@ static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
        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 @@ struct btrfs_root *open_ctree(struct super_block *sb,
        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 fadf69a2764b316828f82d31be8490c0dcf57739..dc84daee6bc472dbc480efd7ad179933277c5eb4 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -267,7 +267,7 @@ static int caching_kthread(void *data)
        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 @@ again:
                        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 @@ next:
 
 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 e51d2bc532f8fa95a0febf2ab4682547f133b746..cdbb5022da52df1e2b33593650401021077ba280 100644 (file)
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -42,10 +42,8 @@ static noinline void put_transaction(struct btrfs_transaction *transaction)
 
 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 @@ static int update_cowonly_root(struct btrfs_trans_handle *trans,
                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 @@ static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
 
                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 @@ static void update_super_roots(struct btrfs_root *root)
        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 961c3ee5a2e10697a120c2dbd7c0dd6d639f27ab..663c67404918dd30fb1c5cf0943b07b2455018bd 100644 (file)
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -107,4 +107,5 @@ int btrfs_record_root_in_trans(struct btrfs_trans_handle *trans,
                                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