Commit 2ecb7923 authored by Miao Xie's avatar Miao Xie Committed by Chris Mason
Browse files

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: default avatarMiao Xie <miaox@cn.fujitsu.com>
parent 48c03c4b

fs/btrfs/ctree.h

+1 −1
Original line number Diff line number Diff line
@@ -1491,9 +1491,9 @@ struct btrfs_root { 
	wait_queue_head_t log_commit_wait[2];

	atomic_t log_writers;

	atomic_t log_commit[2];

	atomic_t log_batch;

	unsigned long log_transid;

	unsigned long last_log_commit;

	unsigned long log_batch;

	pid_t log_start_pid;

	bool log_multiple_pids;

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -1168,8 +1168,8 @@ static void __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize, 
	atomic_set(&root->log_commit[0], 0);

	atomic_set(&root->log_commit[1], 0);

	atomic_set(&root->log_writers, 0);

	atomic_set(&root->log_batch, 0);

	atomic_set(&root->orphan_inodes, 0);

	root->log_batch = 0;

	root->log_transid = 0;

	root->last_log_commit = 0;

	extent_io_tree_init(&root->dirty_log_pages,

fs/btrfs/file.c

+2 −2
Original line number Diff line number Diff line
@@ -1551,9 +1551,9 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 
	 * ordered range does a filemape_write_and_wait_range which is why we

	 * don't do it above like other file systems.

	 */

	root->log_batch++;

	atomic_inc(&root->log_batch);

	btrfs_wait_ordered_range(inode, start, end);

	root->log_batch++;

	atomic_inc(&root->log_batch);



	/*

	 * check the transaction that last modified this inode

fs/btrfs/tree-log.c

+5 −7
Original line number Diff line number Diff line
@@ -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();

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