lockd: nlmclnt_reclaim(): avoid stack overflow
Even though nlmclnt_reclaim() is only one call into the stack frame,
928 bytes on the stack seems like a lot. Recode to dynamically
allocate the request structure once from within the reclaimer task,
then pass this pointer into nlmclnt_reclaim() for reuse on
subsequent calls.
smatch analysis:
fs/lockd/clntproc.c:620 nlmclnt_reclaim() warn: 'reqst' puts
928 bytes on stack
Also remove redundant assignment of 0 after memset.
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 4885b53..6cd673d 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -220,10 +220,19 @@
{
struct nlm_host *host = (struct nlm_host *) ptr;
struct nlm_wait *block;
+ struct nlm_rqst *req;
struct file_lock *fl, *next;
u32 nsmstate;
struct net *net = host->net;
+ req = kmalloc(sizeof(*req), GFP_KERNEL);
+ if (!req) {
+ printk(KERN_ERR "lockd: reclaimer unable to alloc memory."
+ " Locks for %s won't be reclaimed!\n",
+ host->h_name);
+ return 0;
+ }
+
allow_signal(SIGKILL);
down_write(&host->h_rwsem);
@@ -253,7 +262,7 @@
*/
if (signalled())
continue;
- if (nlmclnt_reclaim(host, fl) != 0)
+ if (nlmclnt_reclaim(host, fl, req) != 0)
continue;
list_add_tail(&fl->fl_u.nfs_fl.list, &host->h_granted);
if (host->h_nsmstate != nsmstate) {
@@ -279,5 +288,6 @@
/* Release host handle after use */
nlmclnt_release_host(host);
lockd_down(net);
+ kfree(req);
return 0;
}