Btrfs: get forced transaction commits via workqueue

Signed-off-by: Chris Mason <chris.mason@oracle.com>

4 files changed, 27 insertions, 14 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 74e6aadf6bb7..e93ba1a5c812 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -283,6 +283,7 @@ struct btrfs_block_group_cache {
 struct crypto_hash;
 
 struct btrfs_fs_info {
+        spinlock_t hash_lock;
         struct btrfs_root *extent_root;
         struct btrfs_root *tree_root;
         struct btrfs_root *dev_root;
@@ -308,10 +309,11 @@ struct btrfs_fs_info {
         struct mutex trans_mutex;
         struct mutex fs_mutex;
         struct list_head trans_list;
+        struct list_head dead_roots;
         struct crypto_hash *hash_tfm;
         struct delayed_work trans_work;
-        spinlock_t hash_lock;
         int do_barriers;
+        int closing;
 };
 
 /*
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 048282f06afb..751069c0e9f5 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -563,6 +563,7 @@ struct btrfs_root *open_ctree(struct super_block *sb)
         INIT_RADIX_TREE(&fs_info->block_group_radix, GFP_KERNEL);
         INIT_RADIX_TREE(&fs_info->block_group_data_radix, GFP_KERNEL);
         INIT_LIST_HEAD(&fs_info->trans_list);
+        INIT_LIST_HEAD(&fs_info->dead_roots);
         sb_set_blocksize(sb, 4096);
         fs_info->running_transaction = NULL;
         fs_info->tree_root = tree_root;
@@ -577,6 +578,8 @@ struct btrfs_root *open_ctree(struct super_block *sb)
         fs_info->do_barriers = 1;
         fs_info->extent_tree_insert_nr = 0;
         fs_info->extent_tree_prealloc_nr = 0;
+        fs_info->closing = 0;
+
         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
         BTRFS_I(fs_info->btree_inode)->root = tree_root;
         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
@@ -746,6 +749,7 @@ int close_ctree(struct btrfs_root *root)
         struct btrfs_trans_handle *trans;
         struct btrfs_fs_info *fs_info = root->fs_info;
 
+        fs_info->closing = 1;
         btrfs_transaction_flush_work(root);
         mutex_lock(&fs_info->fs_mutex);
         trans = btrfs_start_transaction(root, 1);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index bf7eef67ba0b..b859db395fd5 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -12,12 +12,10 @@ static struct workqueue_struct *trans_wq;
 
 #define BTRFS_ROOT_TRANS_TAG 0
 
-#define TRANS_MAGIC 0xE1E10E
 static void put_transaction(struct btrfs_transaction *transaction)
 {
         WARN_ON(transaction->use_count == 0);
         transaction->use_count--;
-        WARN_ON(transaction->magic != TRANS_MAGIC);
         if (transaction->use_count == 0) {
                 WARN_ON(total_trans == 0);
                 total_trans--;
@@ -42,7 +40,6 @@ static int join_transaction(struct btrfs_root *root)
                 cur_trans->transid = root->fs_info->generation;
                 init_waitqueue_head(&cur_trans->writer_wait);
                 init_waitqueue_head(&cur_trans->commit_wait);
-                cur_trans->magic = TRANS_MAGIC;
                 cur_trans->in_commit = 0;
                 cur_trans->use_count = 1;
                 cur_trans->commit_done = 0;
@@ -83,7 +80,6 @@ struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
         h->block_group = NULL;
         root->fs_info->running_transaction->use_count++;
         mutex_unlock(&root->fs_info->trans_mutex);
-        h->magic = h->magic2 = TRANS_MAGIC;
         return h;
 }
 
@@ -92,8 +88,6 @@ int btrfs_end_transaction(struct btrfs_trans_handle *trans,
 {
         struct btrfs_transaction *cur_trans;
 
-        WARN_ON(trans->magic != TRANS_MAGIC);
-        WARN_ON(trans->magic2 != TRANS_MAGIC);
         mutex_lock(&root->fs_info->trans_mutex);
         cur_trans = root->fs_info->running_transaction;
         WARN_ON(cur_trans->num_writers < 1);
@@ -257,8 +251,8 @@ static int drop_dirty_roots(struct btrfs_root *tree_root,
         struct dirty_root *dirty;
         struct btrfs_trans_handle *trans;
         int ret;
-
         while(!list_empty(list)) {
+                mutex_lock(&tree_root->fs_info->fs_mutex);
                 dirty = list_entry(list->next, struct dirty_root, list);
                 list_del_init(&dirty->list);
                 trans = btrfs_start_transaction(tree_root, 1);
@@ -271,6 +265,7 @@ static int drop_dirty_roots(struct btrfs_root *tree_root,
                 ret = btrfs_end_transaction(trans, tree_root);
                 BUG_ON(ret);
                 kfree(dirty);
+                mutex_unlock(&tree_root->fs_info->fs_mutex);
         }
         return 0;
 }
@@ -346,10 +341,18 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans,
         wake_up(&cur_trans->commit_wait);
         put_transaction(cur_trans);
         put_transaction(cur_trans);
+        if (root->fs_info->closing)
+                list_splice_init(&root->fs_info->dead_roots, &dirty_fs_roots);
+        else
+                list_splice_init(&dirty_fs_roots, &root->fs_info->dead_roots);
         mutex_unlock(&root->fs_info->trans_mutex);
         kmem_cache_free(btrfs_trans_handle_cachep, trans);
 
-        drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
+        if (root->fs_info->closing) {
+                mutex_unlock(&root->fs_info->fs_mutex);
+                drop_dirty_roots(root->fs_info->tree_root, &dirty_fs_roots);
+                mutex_lock(&root->fs_info->fs_mutex);
+        }
         return ret;
 }
 
@@ -362,11 +365,19 @@ void btrfs_transaction_cleaner(struct work_struct *work)
         struct btrfs_root *root = fs_info->tree_root;
         struct btrfs_transaction *cur;
         struct btrfs_trans_handle *trans;
+        struct list_head dirty_roots;
         unsigned long now;
         unsigned long delay = HZ * 30;
         int ret;
 
-printk("btrfs transaction cleaner\n");
+        INIT_LIST_HEAD(&dirty_roots);
+        mutex_lock(&root->fs_info->trans_mutex);
+        list_splice_init(&root->fs_info->dead_roots, &dirty_roots);
+        mutex_unlock(&root->fs_info->trans_mutex);
+
+        if (!list_empty(&dirty_roots)) {
+                drop_dirty_roots(root, &dirty_roots);
+        }
         mutex_lock(&root->fs_info->fs_mutex);
         mutex_lock(&root->fs_info->trans_mutex);
         cur = root->fs_info->running_transaction;
@@ -381,7 +392,6 @@ printk("btrfs transaction cleaner\n");
                 goto out;
         }
         mutex_unlock(&root->fs_info->trans_mutex);
-printk("forcing commit\n");
         trans = btrfs_start_transaction(root, 1);
         ret = btrfs_commit_transaction(trans, root);
 out:
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 0b08208be853..f25b4900db45 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -8,7 +8,6 @@ struct btrfs_transaction {
         int in_commit;
         int use_count;
         int commit_done;
-        int magic;
         struct list_head list;
         struct radix_tree_root dirty_pages;
         unsigned long start_time;
@@ -17,13 +16,11 @@ struct btrfs_transaction {
 };
 
 struct btrfs_trans_handle {
-        int magic;
         u64 transid;
         unsigned long blocks_reserved;
         unsigned long blocks_used;
         struct btrfs_transaction *transaction;
         struct btrfs_block_group_cache *block_group;
-        int magic2;
 };