On Tue, Sep 21, 2010 at 04:38:12PM -0400, Bryan Schumaker wrote:
> lockd: Mostly remove BKL from the server
I wish I had better file-locking tests: testing of cross-node gfs2
conflicts would be especially useful. This all looks right, though.
Applying.
--b.
>
> This patch removes all but one call to lock_kernel() from the server.
>
> Signed-off-by: Bryan Schumaker <bjschuma@xxxxxxxxxx>
> ---
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 031c656..a336e83 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -230,9 +230,7 @@ static void nlm4svc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlm4svc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlm4svc_callback_ops = {
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index 84055d3..6f1ef00 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -52,12 +52,13 @@ static const struct rpc_call_ops nlmsvc_grant_ops;
> * The list of blocked locks to retry
> */
> static LIST_HEAD(nlm_blocked);
> +static DEFINE_SPINLOCK(nlm_blocked_lock);
>
> /*
> * Insert a blocked lock into the global list
> */
> static void
> -nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +nlmsvc_insert_block_locked(struct nlm_block *block, unsigned long when)
> {
> struct nlm_block *b;
> struct list_head *pos;
> @@ -87,6 +88,13 @@ nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> block->b_when = when;
> }
>
> +static void nlmsvc_insert_block(struct nlm_block *block, unsigned long when)
> +{
> + spin_lock(&nlm_blocked_lock);
> + nlmsvc_insert_block_locked(block, when);
> + spin_unlock(&nlm_blocked_lock);
> +}
> +
> /*
> * Remove a block from the global list
> */
> @@ -94,7 +102,9 @@ static inline void
> nlmsvc_remove_block(struct nlm_block *block)
> {
> if (!list_empty(&block->b_list)) {
> + spin_lock(&nlm_blocked_lock);
> list_del_init(&block->b_list);
> + spin_unlock(&nlm_blocked_lock);
> nlmsvc_release_block(block);
> }
> }
> @@ -651,7 +661,7 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> struct nlm_block *block;
> int rc = -ENOENT;
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> list_for_each_entry(block, &nlm_blocked, b_list) {
> if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
> dprintk("lockd: nlmsvc_notify_blocked block %p flags %d\n",
> @@ -665,13 +675,13 @@ static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
> } else if (result == 0)
> block->b_granted = 1;
>
> - nlmsvc_insert_block(block, 0);
> + nlmsvc_insert_block_locked(block, 0);
> svc_wake_up(block->b_daemon);
> rc = 0;
> break;
> }
> }
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> if (rc == -ENOENT)
> printk(KERN_WARNING "lockd: grant for unknown block\n");
> return rc;
> @@ -803,7 +813,7 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
>
> dprintk("lockd: GRANT_MSG RPC callback\n");
>
> - lock_kernel();
> + spin_lock(&nlm_blocked_lock);
> /* if the block is not on a list at this point then it has
> * been invalidated. Don't try to requeue it.
> *
> @@ -825,19 +835,20 @@ static void nlmsvc_grant_callback(struct rpc_task *task, void *data)
> /* Call was successful, now wait for client callback */
> timeout = 60 * HZ;
> }
> - nlmsvc_insert_block(block, timeout);
> + nlmsvc_insert_block_locked(block, timeout);
> svc_wake_up(block->b_daemon);
> out:
> - unlock_kernel();
> + spin_unlock(&nlm_blocked_lock);
> }
>
> +/*
> + * FIXME: nlmsvc_release_block() grabs a mutex. This is not allowed for an
> + * .rpc_release rpc_call_op
> + */
> static void nlmsvc_grant_release(void *data)
> {
> struct nlm_rqst *call = data;
> -
> - lock_kernel();
> nlmsvc_release_block(call->a_block);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_grant_ops = {
> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index 0f2ab74..c3069f3 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -260,9 +260,7 @@ static void nlmsvc_callback_exit(struct rpc_task *task, void *data)
>
> static void nlmsvc_callback_release(void *data)
> {
> - lock_kernel();
> nlm_release_call(data);
> - unlock_kernel();
> }
>
> static const struct rpc_call_ops nlmsvc_callback_ops = {
--
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