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lockd: Fix Oopses due to list manipulation errors.

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The patch "stop abusing file_lock_list introduces a couple of bugs since
the locks may be copied and need to be removed from the lists when they are
destroyed.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2006-03-20 13:44:41 -05:00
parent 26bcbf965f
commit 4c060b5310
3 changed files with 15 additions and 14 deletions
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7
fs/lockd/clntlock.c
View file

@ -213,11 +213,12 @@ reclaimer(void *ptr)
/* First, reclaim all locks that have been marked. */ /* First, reclaim all locks that have been marked. */
restart: restart:
list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) { list_for_each_entry_safe(fl, next, &host->h_reclaim, fl_u.nfs_fl.list) {
list_del(&fl->fl_u.nfs_fl.list); list_del_init(&fl->fl_u.nfs_fl.list);
nlmclnt_reclaim(host, fl);
if (signalled()) if (signalled())
break; continue;
if (nlmclnt_reclaim(host, fl) == 0)
list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
goto restart; goto restart;
} }

15
fs/lockd/clntproc.c
View file

@ -446,12 +446,14 @@ nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl) static void nlmclnt_locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{ {
memcpy(&new->fl_u.nfs_fl, &fl->fl_u.nfs_fl, sizeof(new->fl_u.nfs_fl)); new->fl_u.nfs_fl.state = fl->fl_u.nfs_fl.state;
nlm_get_lockowner(new->fl_u.nfs_fl.owner); new->fl_u.nfs_fl.owner = nlm_get_lockowner(fl->fl_u.nfs_fl.owner);
list_add_tail(&new->fl_u.nfs_fl.list, &fl->fl_u.nfs_fl.owner->host->h_granted);
} }
static void nlmclnt_locks_release_private(struct file_lock *fl) static void nlmclnt_locks_release_private(struct file_lock *fl)
{ {
list_del(&fl->fl_u.nfs_fl.list);
nlm_put_lockowner(fl->fl_u.nfs_fl.owner); nlm_put_lockowner(fl->fl_u.nfs_fl.owner);
fl->fl_ops = NULL; fl->fl_ops = NULL;
} }
@ -466,6 +468,7 @@ static void nlmclnt_locks_init_private(struct file_lock *fl, struct nlm_host *ho
BUG_ON(fl->fl_ops != NULL); BUG_ON(fl->fl_ops != NULL);
fl->fl_u.nfs_fl.state = 0; fl->fl_u.nfs_fl.state = 0;
fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner); fl->fl_u.nfs_fl.owner = nlm_find_lockowner(host, fl->fl_owner);
INIT_LIST_HEAD(&fl->fl_u.nfs_fl.list);
fl->fl_ops = &nlmclnt_lock_ops; fl->fl_ops = &nlmclnt_lock_ops;
} }
@ -552,7 +555,7 @@ nlmclnt_lock(struct nlm_rqst *req, struct file_lock *fl)
if (resp->status == NLM_LCK_GRANTED) { if (resp->status == NLM_LCK_GRANTED) {
fl->fl_u.nfs_fl.state = host->h_state; fl->fl_u.nfs_fl.state = host->h_state;
fl->fl_flags |= FL_SLEEP; fl->fl_flags |= FL_SLEEP;
list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted); /* Ensure the resulting lock will get added to granted list */
do_vfs_lock(fl); do_vfs_lock(fl);
} }
status = nlm_stat_to_errno(resp->status); status = nlm_stat_to_errno(resp->status);
@ -618,12 +621,6 @@ nlmclnt_unlock(struct nlm_rqst *req, struct file_lock *fl)
struct nlm_res *resp = &req->a_res; struct nlm_res *resp = &req->a_res;
int status; int status;
/*
* Remove from the granted list now so the lock doesn't get
* reclaimed while we're stuck in the unlock call.
*/
list_del(&fl->fl_u.nfs_fl.list);
/* /*
* Note: the server is supposed to either grant us the unlock * Note: the server is supposed to either grant us the unlock
* request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either * request, or to deny it with NLM_LCK_DENIED_GRACE_PERIOD. In either

7
fs/lockd/host.c
View file

@ -245,8 +245,12 @@ void nlm_release_host(struct nlm_host *host)
{ {
if (host != NULL) { if (host != NULL) {
dprintk("lockd: release host %s\n", host->h_name); dprintk("lockd: release host %s\n", host->h_name);
atomic_dec(&host->h_count);
BUG_ON(atomic_read(&host->h_count) < 0); BUG_ON(atomic_read(&host->h_count) < 0);
if (atomic_dec_and_test(&host->h_count)) {
BUG_ON(!list_empty(&host->h_lockowners));
BUG_ON(!list_empty(&host->h_granted));
BUG_ON(!list_empty(&host->h_reclaim));
}
} }
} }
@ -334,7 +338,6 @@ nlm_gc_hosts(void)
rpc_destroy_client(host->h_rpcclnt); rpc_destroy_client(host->h_rpcclnt);
} }
} }
BUG_ON(!list_empty(&host->h_lockowners));
kfree(host); kfree(host);
nrhosts--; nrhosts--;
} }