btrfs: enhance transaction abort infrastructure
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index fb5cd5a..5a4999a 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -31,7 +31,7 @@
#define BTRFS_ROOT_TRANS_TAG 0
-static noinline void put_transaction(struct btrfs_transaction *transaction)
+void put_transaction(struct btrfs_transaction *transaction)
{
WARN_ON(atomic_read(&transaction->use_count) == 0);
if (atomic_dec_and_test(&transaction->use_count)) {
@@ -58,6 +58,12 @@
spin_lock(&root->fs_info->trans_lock);
loop:
+ /* The file system has been taken offline. No new transactions. */
+ if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ spin_unlock(&root->fs_info->trans_lock);
+ return -EROFS;
+ }
+
if (root->fs_info->trans_no_join) {
if (!nofail) {
spin_unlock(&root->fs_info->trans_lock);
@@ -67,6 +73,8 @@
cur_trans = root->fs_info->running_transaction;
if (cur_trans) {
+ if (cur_trans->aborted)
+ return cur_trans->aborted;
atomic_inc(&cur_trans->use_count);
atomic_inc(&cur_trans->num_writers);
cur_trans->num_joined++;
@@ -123,6 +131,7 @@
root->fs_info->generation++;
cur_trans->transid = root->fs_info->generation;
root->fs_info->running_transaction = cur_trans;
+ cur_trans->aborted = 0;
spin_unlock(&root->fs_info->trans_lock);
return 0;
@@ -318,6 +327,7 @@
h->use_count = 1;
h->block_rsv = NULL;
h->orig_rsv = NULL;
+ h->aborted = 0;
smp_mb();
if (cur_trans->blocked && may_wait_transaction(root, type)) {
@@ -440,6 +450,7 @@
struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_block_rsv *rsv = trans->block_rsv;
int updates;
+ int err;
smp_mb();
if (cur_trans->blocked || cur_trans->delayed_refs.flushing)
@@ -453,8 +464,11 @@
updates = trans->delayed_ref_updates;
trans->delayed_ref_updates = 0;
- if (updates)
- btrfs_run_delayed_refs(trans, root, updates);
+ if (updates) {
+ err = btrfs_run_delayed_refs(trans, root, updates);
+ if (err) /* Error code will also eval true */
+ return err;
+ }
trans->block_rsv = rsv;
@@ -525,6 +539,11 @@
if (throttle)
btrfs_run_delayed_iputs(root);
+ if (trans->aborted ||
+ root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ return -EIO;
+ }
+
return 0;
}
@@ -690,11 +709,13 @@
ret = btrfs_update_root(trans, tree_root,
&root->root_key,
&root->root_item);
- BUG_ON(ret);
+ if (ret)
+ return ret;
old_root_used = btrfs_root_used(&root->root_item);
ret = btrfs_write_dirty_block_groups(trans, root);
- BUG_ON(ret);
+ if (ret)
+ return ret;
}
if (root != root->fs_info->extent_root)
@@ -705,6 +726,10 @@
/*
* update all the cowonly tree roots on disk
+ *
+ * The error handling in this function may not be obvious. Any of the
+ * failures will cause the file system to go offline. We still need
+ * to clean up the delayed refs.
*/
static noinline int commit_cowonly_roots(struct btrfs_trans_handle *trans,
struct btrfs_root *root)
@@ -715,22 +740,30 @@
int ret;
ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
- BUG_ON(ret);
+ if (ret)
+ return ret;
eb = btrfs_lock_root_node(fs_info->tree_root);
- btrfs_cow_block(trans, fs_info->tree_root, eb, NULL, 0, &eb);
+ ret = btrfs_cow_block(trans, fs_info->tree_root, eb, NULL,
+ 0, &eb);
btrfs_tree_unlock(eb);
free_extent_buffer(eb);
+ if (ret)
+ return ret;
+
ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
- BUG_ON(ret);
+ if (ret)
+ return ret;
while (!list_empty(&fs_info->dirty_cowonly_roots)) {
next = fs_info->dirty_cowonly_roots.next;
list_del_init(next);
root = list_entry(next, struct btrfs_root, dirty_list);
- update_cowonly_root(trans, root);
+ ret = update_cowonly_root(trans, root);
+ if (ret)
+ return ret;
}
down_write(&fs_info->extent_commit_sem);
@@ -874,7 +907,7 @@
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
if (!new_root_item) {
- pending->error = -ENOMEM;
+ ret = pending->error = -ENOMEM;
goto fail;
}
@@ -911,7 +944,7 @@
* insert the directory item
*/
ret = btrfs_set_inode_index(parent_inode, &index);
- BUG_ON(ret);
+ BUG_ON(ret); /* -ENOMEM */
ret = btrfs_insert_dir_item(trans, parent_root,
dentry->d_name.name, dentry->d_name.len,
parent_inode, &key,
@@ -920,12 +953,14 @@
pending->error = -EEXIST;
dput(parent);
goto fail;
- }
+ } else if (ret)
+ goto abort_trans;
btrfs_i_size_write(parent_inode, parent_inode->i_size +
dentry->d_name.len * 2);
ret = btrfs_update_inode(trans, parent_root, parent_inode);
- BUG_ON(ret);
+ if (ret)
+ goto abort_trans;
/*
* pull in the delayed directory update
@@ -934,7 +969,8 @@
* snapshot
*/
ret = btrfs_run_delayed_items(trans, root);
- BUG_ON(ret);
+ if (ret) /* Transaction aborted */
+ goto fail;
record_root_in_trans(trans, root);
btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
@@ -949,10 +985,16 @@
btrfs_set_root_flags(new_root_item, root_flags);
old = btrfs_lock_root_node(root);
- btrfs_cow_block(trans, root, old, NULL, 0, &old);
+ ret = btrfs_cow_block(trans, root, old, NULL, 0, &old);
+ if (ret)
+ goto abort_trans;
+
btrfs_set_lock_blocking(old);
- btrfs_copy_root(trans, root, old, &tmp, objectid);
+ ret = btrfs_copy_root(trans, root, old, &tmp, objectid);
+ if (ret)
+ goto abort_trans;
+
btrfs_tree_unlock(old);
free_extent_buffer(old);
@@ -966,7 +1008,8 @@
ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
btrfs_tree_unlock(tmp);
free_extent_buffer(tmp);
- BUG_ON(ret);
+ if (ret)
+ goto abort_trans;
/*
* insert root back/forward references
@@ -975,19 +1018,28 @@
parent_root->root_key.objectid,
btrfs_ino(parent_inode), index,
dentry->d_name.name, dentry->d_name.len);
- BUG_ON(ret);
+ if (ret)
+ goto fail;
dput(parent);
key.offset = (u64)-1;
pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
- BUG_ON(IS_ERR(pending->snap));
+ if (IS_ERR(pending->snap))
+ goto abort_trans;
- btrfs_reloc_post_snapshot(trans, pending);
+ ret = btrfs_reloc_post_snapshot(trans, pending);
+ if (ret)
+ goto abort_trans;
+ ret = 0;
fail:
kfree(new_root_item);
trans->block_rsv = rsv;
btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
- return 0;
+ return ret;
+
+abort_trans:
+ btrfs_abort_transaction(trans, root, ret);
+ goto fail;
}
/*
@@ -1124,6 +1176,33 @@
return 0;
}
+
+static void cleanup_transaction(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root)
+{
+ struct btrfs_transaction *cur_trans = trans->transaction;
+
+ WARN_ON(trans->use_count > 1);
+
+ spin_lock(&root->fs_info->trans_lock);
+ list_del_init(&cur_trans->list);
+ spin_unlock(&root->fs_info->trans_lock);
+
+ btrfs_cleanup_one_transaction(trans->transaction, root);
+
+ put_transaction(cur_trans);
+ put_transaction(cur_trans);
+
+ trace_btrfs_transaction_commit(root);
+
+ btrfs_scrub_continue(root);
+
+ if (current->journal_info == trans)
+ current->journal_info = NULL;
+
+ kmem_cache_free(btrfs_trans_handle_cachep, trans);
+}
+
/*
* btrfs_transaction state sequence:
* in_commit = 0, blocked = 0 (initial)
@@ -1135,10 +1214,10 @@
struct btrfs_root *root)
{
unsigned long joined = 0;
- struct btrfs_transaction *cur_trans;
+ struct btrfs_transaction *cur_trans = trans->transaction;
struct btrfs_transaction *prev_trans = NULL;
DEFINE_WAIT(wait);
- int ret;
+ int ret = -EIO;
int should_grow = 0;
unsigned long now = get_seconds();
int flush_on_commit = btrfs_test_opt(root, FLUSHONCOMMIT);
@@ -1148,13 +1227,18 @@
btrfs_trans_release_metadata(trans, root);
trans->block_rsv = NULL;
+ if (cur_trans->aborted)
+ goto cleanup_transaction;
+
/* make a pass through all the delayed refs we have so far
* any runnings procs may add more while we are here
*/
ret = btrfs_run_delayed_refs(trans, root, 0);
- BUG_ON(ret);
+ if (ret)
+ goto cleanup_transaction;
cur_trans = trans->transaction;
+
/*
* set the flushing flag so procs in this transaction have to
* start sending their work down.
@@ -1162,19 +1246,20 @@
cur_trans->delayed_refs.flushing = 1;
ret = btrfs_run_delayed_refs(trans, root, 0);
- BUG_ON(ret);
+ if (ret)
+ goto cleanup_transaction;
spin_lock(&cur_trans->commit_lock);
if (cur_trans->in_commit) {
spin_unlock(&cur_trans->commit_lock);
atomic_inc(&cur_trans->use_count);
- btrfs_end_transaction(trans, root);
+ ret = btrfs_end_transaction(trans, root);
wait_for_commit(root, cur_trans);
put_transaction(cur_trans);
- return 0;
+ return ret;
}
trans->transaction->in_commit = 1;
@@ -1218,7 +1303,8 @@
}
ret = btrfs_run_delayed_items(trans, root);
- BUG_ON(ret);
+ if (ret)
+ goto cleanup_transaction;
/*
* rename don't use btrfs_join_transaction, so, once we
@@ -1260,13 +1346,22 @@
mutex_lock(&root->fs_info->reloc_mutex);
ret = btrfs_run_delayed_items(trans, root);
- BUG_ON(ret);
+ if (ret) {
+ mutex_unlock(&root->fs_info->reloc_mutex);
+ goto cleanup_transaction;
+ }
ret = create_pending_snapshots(trans, root->fs_info);
- BUG_ON(ret);
+ if (ret) {
+ mutex_unlock(&root->fs_info->reloc_mutex);
+ goto cleanup_transaction;
+ }
ret = btrfs_run_delayed_refs(trans, root, (unsigned long)-1);
- BUG_ON(ret);
+ if (ret) {
+ mutex_unlock(&root->fs_info->reloc_mutex);
+ goto cleanup_transaction;
+ }
/*
* make sure none of the code above managed to slip in a
@@ -1293,7 +1388,10 @@
mutex_lock(&root->fs_info->tree_log_mutex);
ret = commit_fs_roots(trans, root);
- BUG_ON(ret);
+ if (ret) {
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ goto cleanup_transaction;
+ }
/* commit_fs_roots gets rid of all the tree log roots, it is now
* safe to free the root of tree log roots
@@ -1301,7 +1399,10 @@
btrfs_free_log_root_tree(trans, root->fs_info);
ret = commit_cowonly_roots(trans, root);
- BUG_ON(ret);
+ if (ret) {
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ goto cleanup_transaction;
+ }
btrfs_prepare_extent_commit(trans, root);
@@ -1335,8 +1436,18 @@
wake_up(&root->fs_info->transaction_wait);
ret = btrfs_write_and_wait_transaction(trans, root);
- BUG_ON(ret);
- write_ctree_super(trans, root, 0);
+ if (ret) {
+ btrfs_error(root->fs_info, ret,
+ "Error while writing out transaction.");
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ goto cleanup_transaction;
+ }
+
+ ret = write_ctree_super(trans, root, 0);
+ if (ret) {
+ mutex_unlock(&root->fs_info->tree_log_mutex);
+ goto cleanup_transaction;
+ }
/*
* the super is written, we can safely allow the tree-loggers
@@ -1372,6 +1483,15 @@
btrfs_run_delayed_iputs(root);
return ret;
+
+cleanup_transaction:
+ btrfs_printk(root->fs_info, "Skipping commit of aborted transaction.\n");
+// WARN_ON(1);
+ if (current->journal_info == trans)
+ current->journal_info = NULL;
+ cleanup_transaction(trans, root);
+
+ return ret;
}
/*