diff options
Diffstat (limited to 'fs/ocfs2/dlm/userdlm.c')
| -rw-r--r-- | fs/ocfs2/dlm/userdlm.c | 74 |
1 files changed, 56 insertions, 18 deletions
diff --git a/fs/ocfs2/dlm/userdlm.c b/fs/ocfs2/dlm/userdlm.c index c3764f4744ee..74ca4e5f9765 100644 --- a/fs/ocfs2/dlm/userdlm.c +++ b/fs/ocfs2/dlm/userdlm.c @@ -139,6 +139,10 @@ static void user_ast(void *opaque) return; } + mlog_bug_on_msg(lockres->l_requested == LKM_IVMODE, + "Lockres %s, requested ivmode. flags 0x%x\n", + lockres->l_name, lockres->l_flags); + /* we're downconverting. */ if (lockres->l_requested < lockres->l_level) { if (lockres->l_requested <= @@ -229,23 +233,42 @@ static void user_unlock_ast(void *opaque, enum dlm_status status) mlog(0, "UNLOCK AST called on lock %s\n", lockres->l_name); - if (status != DLM_NORMAL) + if (status != DLM_NORMAL && status != DLM_CANCELGRANT) mlog(ML_ERROR, "Dlm returns status %d\n", status); spin_lock(&lockres->l_lock); - if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) + /* The teardown flag gets set early during the unlock process, + * so test the cancel flag to make sure that this ast isn't + * for a concurrent cancel. */ + if (lockres->l_flags & USER_LOCK_IN_TEARDOWN + && !(lockres->l_flags & USER_LOCK_IN_CANCEL)) { lockres->l_level = LKM_IVMODE; - else { + } else if (status == DLM_CANCELGRANT) { + mlog(0, "Lock %s, cancel fails, flags 0x%x\n", + lockres->l_name, lockres->l_flags); + /* We tried to cancel a convert request, but it was + * already granted. Don't clear the busy flag - the + * ast should've done this already. */ + BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL)); + lockres->l_flags &= ~USER_LOCK_IN_CANCEL; + goto out_noclear; + } else { + BUG_ON(!(lockres->l_flags & USER_LOCK_IN_CANCEL)); + /* Cancel succeeded, we want to re-queue */ + mlog(0, "Lock %s, cancel succeeds, flags 0x%x\n", + lockres->l_name, lockres->l_flags); lockres->l_requested = LKM_IVMODE; /* cancel an * upconvert * request. */ lockres->l_flags &= ~USER_LOCK_IN_CANCEL; /* we want the unblock thread to look at it again * now. */ - __user_dlm_queue_lockres(lockres); + if (lockres->l_flags & USER_LOCK_BLOCKED) + __user_dlm_queue_lockres(lockres); } lockres->l_flags &= ~USER_LOCK_BUSY; +out_noclear: spin_unlock(&lockres->l_lock); wake_up(&lockres->l_event); @@ -268,13 +291,26 @@ static void user_dlm_unblock_lock(void *opaque) spin_lock(&lockres->l_lock); - BUG_ON(!(lockres->l_flags & USER_LOCK_BLOCKED)); - BUG_ON(!(lockres->l_flags & USER_LOCK_QUEUED)); + mlog_bug_on_msg(!(lockres->l_flags & USER_LOCK_QUEUED), + "Lockres %s, flags 0x%x\n", + lockres->l_name, lockres->l_flags); - /* notice that we don't clear USER_LOCK_BLOCKED here. That's - * for user_ast to do. */ + /* notice that we don't clear USER_LOCK_BLOCKED here. If it's + * set, we want user_ast clear it. */ lockres->l_flags &= ~USER_LOCK_QUEUED; + /* It's valid to get here and no longer be blocked - if we get + * several basts in a row, we might be queued by the first + * one, the unblock thread might run and clear the queued + * flag, and finally we might get another bast which re-queues + * us before our ast for the downconvert is called. */ + if (!(lockres->l_flags & USER_LOCK_BLOCKED)) { + mlog(0, "Lockres %s, flags 0x%x: queued but not blocking\n", + lockres->l_name, lockres->l_flags); + spin_unlock(&lockres->l_lock); + goto drop_ref; + } + if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) { mlog(0, "lock is in teardown so we do nothing\n"); spin_unlock(&lockres->l_lock); @@ -282,7 +318,9 @@ static void user_dlm_unblock_lock(void *opaque) } if (lockres->l_flags & USER_LOCK_BUSY) { - mlog(0, "BUSY flag detected...\n"); + mlog(0, "Cancel lock %s, flags 0x%x\n", + lockres->l_name, lockres->l_flags); + if (lockres->l_flags & USER_LOCK_IN_CANCEL) { spin_unlock(&lockres->l_lock); goto drop_ref; @@ -296,14 +334,7 @@ static void user_dlm_unblock_lock(void *opaque) LKM_CANCEL, user_unlock_ast, lockres); - if (status == DLM_CANCELGRANT) { - /* If we got this, then the ast was fired - * before we could cancel. We cleanup our - * state, and restart the function. */ - spin_lock(&lockres->l_lock); - lockres->l_flags &= ~USER_LOCK_IN_CANCEL; - spin_unlock(&lockres->l_lock); - } else if (status != DLM_NORMAL) + if (status != DLM_NORMAL) user_log_dlm_error("dlmunlock", status, lockres); goto drop_ref; } @@ -581,6 +612,14 @@ int user_dlm_destroy_lock(struct user_lock_res *lockres) mlog(0, "asked to destroy %s\n", lockres->l_name); spin_lock(&lockres->l_lock); + if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) { + mlog(0, "Lock is already torn down\n"); + spin_unlock(&lockres->l_lock); + return 0; + } + + lockres->l_flags |= USER_LOCK_IN_TEARDOWN; + while (lockres->l_flags & USER_LOCK_BUSY) { spin_unlock(&lockres->l_lock); @@ -606,7 +645,6 @@ int user_dlm_destroy_lock(struct user_lock_res *lockres) lockres->l_flags &= ~USER_LOCK_ATTACHED; lockres->l_flags |= USER_LOCK_BUSY; - lockres->l_flags |= USER_LOCK_IN_TEARDOWN; spin_unlock(&lockres->l_lock); mlog(0, "unlocking lockres %s\n", lockres->l_name); |