Btrfs: fix unprotected ->log_batch
We forget to protect ->log_batch when syncing a file, this patch fix
this problem by atomic operation. And ->log_batch is used to check
if there are parallel sync operations or not, so it is unnecessary to
reset it to 0 after the sync operation of the current log tree complete.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f9b0fc9..038a522 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -147,7 +147,7 @@
root->log_multiple_pids = true;
}
- root->log_batch++;
+ atomic_inc(&root->log_batch);
atomic_inc(&root->log_writers);
mutex_unlock(&root->log_mutex);
return 0;
@@ -166,7 +166,7 @@
err = ret;
}
mutex_unlock(&root->fs_info->tree_log_mutex);
- root->log_batch++;
+ atomic_inc(&root->log_batch);
atomic_inc(&root->log_writers);
mutex_unlock(&root->log_mutex);
return err;
@@ -2036,7 +2036,7 @@
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
wait_log_commit(trans, root, root->log_transid - 1);
while (1) {
- unsigned long batch = root->log_batch;
+ int batch = atomic_read(&root->log_batch);
/* when we're on an ssd, just kick the log commit out */
if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
mutex_unlock(&root->log_mutex);
@@ -2044,7 +2044,7 @@
mutex_lock(&root->log_mutex);
}
wait_for_writer(trans, root);
- if (batch == root->log_batch)
+ if (batch == atomic_read(&root->log_batch))
break;
}
@@ -2073,7 +2073,6 @@
btrfs_set_root_node(&log->root_item, log->node);
- root->log_batch = 0;
root->log_transid++;
log->log_transid = root->log_transid;
root->log_start_pid = 0;
@@ -2086,7 +2085,7 @@
mutex_unlock(&root->log_mutex);
mutex_lock(&log_root_tree->log_mutex);
- log_root_tree->log_batch++;
+ atomic_inc(&log_root_tree->log_batch);
atomic_inc(&log_root_tree->log_writers);
mutex_unlock(&log_root_tree->log_mutex);
@@ -2156,7 +2155,6 @@
btrfs_set_super_log_root_level(root->fs_info->super_for_commit,
btrfs_header_level(log_root_tree->node));
- log_root_tree->log_batch = 0;
log_root_tree->log_transid++;
smp_mb();