[PATCH V4 10/12] Btrfs: fix unprotected ->log_batch
From: Miao Xie <hidden>
Date: 2012-09-06 10:44:52
Subsystem:
btrfs file system, filesystems (vfs and infrastructure), the rest · Maintainers:
Chris Mason, David Sterba, Alexander Viro, Christian Brauner, Linus Torvalds
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 <redacted> --- Changelog v1 -> v4: - new patch. --- fs/btrfs/ctree.h | 2 +- fs/btrfs/disk-io.c | 2 +- fs/btrfs/file.c | 4 ++-- fs/btrfs/tree-log.c | 12 +++++------- 4 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 171458a..dbb461f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h@@ -1490,9 +1490,9 @@ 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;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 0c0f8eb..7fb7069 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c@@ -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,
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 9aa01ec..af888da 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c@@ -1520,9 +1520,9 @@ 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
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index c86670f..71a2d19 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c@@ -146,7 +146,7 @@ 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;
@@ -165,7 +165,7 @@ 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;
@@ -2037,7 +2037,7 @@ 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);
@@ -2045,7 +2045,7 @@ 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; }
@@ -2074,7 +2074,6 @@ 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;
@@ -2087,7 +2086,7 @@ 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);
@@ -2157,7 +2156,6 @@ 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();
--
1.7.6.5