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Btrfs: fix unprotected ->log_batch

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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>
This commit is contained in:
Miao Xie
2012-09-06 04:04:27 -06:00
committed by Chris Mason
parent 48c03c4bcf
commit 2ecb79239b
4 changed files with 9 additions and 11 deletions
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12
fs/btrfs/tree-log.c
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@@ -147,7 +147,7 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
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 @@ static int start_log_trans(struct btrfs_trans_handle *trans,
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 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
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 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
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 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
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 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
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 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
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();