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| author | Liu Bo <bo.li.liu@oracle.com> | 2013-02-27 13:28:25 +0000 |
|---|---|---|
| committer | Josef Bacik <jbacik@fusionio.com> | 2013-02-28 13:33:52 -0500 |
| commit | f094ac32aba3a51c00e970a2ea029339af2ca048 (patch) | |
| tree | 88330927384b9ff597f6330a000e463079c02846 | |
| parent | 3321719ed67440bba1b0c5ae19c30d640263ccc8 (diff) | |
| download | blackbird-op-linux-f094ac32aba3a51c00e970a2ea029339af2ca048.tar.gz blackbird-op-linux-f094ac32aba3a51c00e970a2ea029339af2ca048.zip | |
Btrfs: fix NULL pointer after aborting a transaction
While doing cleanup work on an aborted transaction, we've set
the global running transaction pointer to NULL _before_ waiting all
other transaction handles to finish, so others'd hit NULL pointer
crash when referencing the global running transaction pointer.
This first sets a hint to avoid new transaction handle joining, then
waits other existing handles to abort or finish so that we can safely
set the above global pointer to NULL.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
| -rw-r--r-- | fs/btrfs/transaction.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 4330433b7b4f..3733c4939a27 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1447,6 +1447,7 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans, struct btrfs_root *root, int err) { struct btrfs_transaction *cur_trans = trans->transaction; + DEFINE_WAIT(wait); WARN_ON(trans->use_count > 1); @@ -1455,8 +1456,13 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans, spin_lock(&root->fs_info->trans_lock); list_del_init(&cur_trans->list); if (cur_trans == root->fs_info->running_transaction) { + root->fs_info->trans_no_join = 1; + spin_unlock(&root->fs_info->trans_lock); + wait_event(cur_trans->writer_wait, + atomic_read(&cur_trans->num_writers) == 1); + + spin_lock(&root->fs_info->trans_lock); root->fs_info->running_transaction = NULL; - root->fs_info->trans_no_join = 0; } spin_unlock(&root->fs_info->trans_lock); |
