From 2ecb79239bcd04c9d410f4cdce16adb6840b19da Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 6 Sep 2012 04:04:27 -0600 Subject: [PATCH] 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 --- 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 2990a7ea6248..6923b9e4f90d 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -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; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 0dcfb998229e..34717ac2416a 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 a9d7815cf58e..793bc89c660f 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -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 diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index f9b0fc911661..038a5229404a 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -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();