diff options
Diffstat (limited to 'fs/dlm/user.c')
| -rw-r--r-- | fs/dlm/user.c | 77 |
1 files changed, 44 insertions, 33 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c index 27a75ce571c..c978c67b1ef 100644 --- a/fs/dlm/user.c +++ b/fs/dlm/user.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2006 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions @@ -128,35 +128,30 @@ static void compat_output(struct dlm_lock_result *res, } #endif +/* we could possibly check if the cancel of an orphan has resulted in the lkb + being removed and then remove that lkb from the orphans list and free it */ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) { struct dlm_ls *ls; struct dlm_user_args *ua; struct dlm_user_proc *proc; - int remove_ownqueue = 0; + int eol = 0, ast_type; - /* dlm_clear_proc_locks() sets ORPHAN/DEAD flag on each - lkb before dealing with it. We need to check this - flag before taking ls_clear_proc_locks mutex because if - it's set, dlm_clear_proc_locks() holds the mutex. */ - - if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { - /* log_print("user_add_ast skip1 %x", lkb->lkb_flags); */ + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) return; - } ls = lkb->lkb_resource->res_ls; mutex_lock(&ls->ls_clear_proc_locks); /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed - lkb->ua so we can't try to use it. */ + lkb->ua so we can't try to use it. This second check is necessary + for cases where a completion ast is received for an operation that + began before clear_proc_locks did its cancel/unlock. */ - if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) { - /* log_print("user_add_ast skip2 %x", lkb->lkb_flags); */ + if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) goto out; - } DLM_ASSERT(lkb->lkb_astparam, dlm_print_lkb(lkb);); ua = (struct dlm_user_args *)lkb->lkb_astparam; @@ -166,28 +161,42 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) goto out; spin_lock(&proc->asts_spin); - if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) { + + ast_type = lkb->lkb_ast_type; + lkb->lkb_ast_type |= type; + + if (!ast_type) { kref_get(&lkb->lkb_ref); list_add_tail(&lkb->lkb_astqueue, &proc->asts); - lkb->lkb_ast_type |= type; wake_up_interruptible(&proc->wait); } - - /* noqueue requests that fail may need to be removed from the - proc's locks list, there should be a better way of detecting - this situation than checking all these things... */ - - if (type == AST_COMP && lkb->lkb_grmode == DLM_LOCK_IV && - ua->lksb.sb_status == -EAGAIN && !list_empty(&lkb->lkb_ownqueue)) - remove_ownqueue = 1; - - /* unlocks or cancels of waiting requests need to be removed from the - proc's unlocking list, again there must be a better way... */ - - if (ua->lksb.sb_status == -DLM_EUNLOCK || + if (type == AST_COMP && (ast_type & AST_COMP)) + log_debug(ls, "ast overlap %x status %x %x", + lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags); + + /* Figure out if this lock is at the end of its life and no longer + available for the application to use. The lkb still exists until + the final ast is read. A lock becomes EOL in three situations: + 1. a noqueue request fails with EAGAIN + 2. an unlock completes with EUNLOCK + 3. a cancel of a waiting request completes with ECANCEL + An EOL lock needs to be removed from the process's list of locks. + And we can't allow any new operation on an EOL lock. This is + not related to the lifetime of the lkb struct which is managed + entirely by refcount. */ + + if (type == AST_COMP && + lkb->lkb_grmode == DLM_LOCK_IV && + ua->lksb.sb_status == -EAGAIN) + eol = 1; + else if (ua->lksb.sb_status == -DLM_EUNLOCK || (ua->lksb.sb_status == -DLM_ECANCEL && lkb->lkb_grmode == DLM_LOCK_IV)) - remove_ownqueue = 1; + eol = 1; + if (eol) { + lkb->lkb_ast_type &= ~AST_BAST; + lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; + } /* We want to copy the lvb to userspace when the completion ast is read if the status is 0, the lock has an lvb and @@ -204,11 +213,13 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type) spin_unlock(&proc->asts_spin); - if (remove_ownqueue) { + if (eol) { spin_lock(&ua->proc->locks_spin); - list_del_init(&lkb->lkb_ownqueue); + if (!list_empty(&lkb->lkb_ownqueue)) { + list_del_init(&lkb->lkb_ownqueue); + dlm_put_lkb(lkb); + } spin_unlock(&ua->proc->locks_spin); - dlm_put_lkb(lkb); } out: mutex_unlock(&ls->ls_clear_proc_locks); |