1 files changed, 107 insertions, 106 deletions

diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c
index c38b2b8ffd1d..737f185aad8d 100644
--- a/fs/dlm/plock.c
+++ b/fs/dlm/plock.c
@@ -13,26 +13,28 @@
 #include "dlm_internal.h"
 #include "lockspace.h"
 
-static spinlock_t ops_lock;
-static struct list_head send_list;
-static struct list_head recv_list;
-static wait_queue_head_t send_wq;
-static wait_queue_head_t recv_wq;
+static DEFINE_SPINLOCK(ops_lock);
+static LIST_HEAD(send_list);
+static LIST_HEAD(recv_list);
+static DECLARE_WAIT_QUEUE_HEAD(send_wq);
+static DECLARE_WAIT_QUEUE_HEAD(recv_wq);
 
-struct plock_op {
-	struct list_head list;
-	int done;
-	struct dlm_plock_info info;
-};
-
-struct plock_xop {
-	struct plock_op xop;
-	int (*callback)(struct file_lock *fl, int result);
+struct plock_async_data {
 	void *fl;
 	void *file;
 	struct file_lock flc;
+	int (*callback)(struct file_lock *fl, int result);
 };
 
+struct plock_op {
+	struct list_head list;
+	int done;
+	/* if lock op got interrupted while waiting dlm_controld reply */
+	bool sigint;
+	struct dlm_plock_info info;
+	/* if set indicates async handling */
+	struct plock_async_data *data;
+};
 
 static inline void set_version(struct dlm_plock_info *info)
 {
@@ -58,10 +60,15 @@ static int check_version(struct dlm_plock_info *info)
 	return 0;
 }
 
+static void dlm_release_plock_op(struct plock_op *op)
+{
+	kfree(op->data);
+	kfree(op);
+}
+
 static void send_op(struct plock_op *op)
 {
 	set_version(&op->info);
-	INIT_LIST_HEAD(&op->list);
 	spin_lock(&ops_lock);
 	list_add_tail(&op->list, &send_list);
 	spin_unlock(&ops_lock);
@@ -74,8 +81,7 @@ static void send_op(struct plock_op *op)
    abandoned waiter.  So, we have to insert the unlock-close when the
    lock call is interrupted. */
 
-static void do_unlock_close(struct dlm_ls *ls, u64 number,
-			    struct file *file, struct file_lock *fl)
+static void do_unlock_close(const struct dlm_plock_info *info)
 {
 	struct plock_op *op;
 
@@ -84,15 +90,12 @@ static void do_unlock_close(struct dlm_ls *ls, u64 number,
 		return;
 
 	op->info.optype		= DLM_PLOCK_OP_UNLOCK;
-	op->info.pid		= fl->fl_pid;
-	op->info.fsid		= ls->ls_global_id;
-	op->info.number		= number;
+	op->info.pid		= info->pid;
+	op->info.fsid		= info->fsid;
+	op->info.number		= info->number;
 	op->info.start		= 0;
 	op->info.end		= OFFSET_MAX;
-	if (fl->fl_lmops && fl->fl_lmops->lm_grant)
-		op->info.owner	= (__u64) fl->fl_pid;
-	else
-		op->info.owner	= (__u64)(long) fl->fl_owner;
+	op->info.owner		= info->owner;
 
 	op->info.flags |= DLM_PLOCK_FL_CLOSE;
 	send_op(op);
@@ -101,22 +104,21 @@ static void do_unlock_close(struct dlm_ls *ls, u64 number,
 int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 		   int cmd, struct file_lock *fl)
 {
+	struct plock_async_data *op_data;
 	struct dlm_ls *ls;
 	struct plock_op *op;
-	struct plock_xop *xop;
 	int rv;
 
 	ls = dlm_find_lockspace_local(lockspace);
 	if (!ls)
 		return -EINVAL;
 
-	xop = kzalloc(sizeof(*xop), GFP_NOFS);
-	if (!xop) {
+	op = kzalloc(sizeof(*op), GFP_NOFS);
+	if (!op) {
 		rv = -ENOMEM;
 		goto out;
 	}
 
-	op = &xop->xop;
 	op->info.optype		= DLM_PLOCK_OP_LOCK;
 	op->info.pid		= fl->fl_pid;
 	op->info.ex		= (fl->fl_type == F_WRLCK);
@@ -125,46 +127,57 @@ int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 	op->info.number		= number;
 	op->info.start		= fl->fl_start;
 	op->info.end		= fl->fl_end;
+	/* async handling */
 	if (fl->fl_lmops && fl->fl_lmops->lm_grant) {
+		op_data = kzalloc(sizeof(*op_data), GFP_NOFS);
+		if (!op_data) {
+			dlm_release_plock_op(op);
+			rv = -ENOMEM;
+			goto out;
+		}
+
 		/* fl_owner is lockd which doesn't distinguish
 		   processes on the nfs client */
 		op->info.owner	= (__u64) fl->fl_pid;
-		xop->callback	= fl->fl_lmops->lm_grant;
-		locks_init_lock(&xop->flc);
-		locks_copy_lock(&xop->flc, fl);
-		xop->fl		= fl;
-		xop->file	= file;
+		op_data->callback = fl->fl_lmops->lm_grant;
+		locks_init_lock(&op_data->flc);
+		locks_copy_lock(&op_data->flc, fl);
+		op_data->fl		= fl;
+		op_data->file	= file;
+
+		op->data = op_data;
+
+		send_op(op);
+		rv = FILE_LOCK_DEFERRED;
+		goto out;
 	} else {
 		op->info.owner	= (__u64)(long) fl->fl_owner;
-		xop->callback	= NULL;
 	}
 
 	send_op(op);
 
-	if (xop->callback == NULL) {
-		rv = wait_event_interruptible(recv_wq, (op->done != 0));
-		if (rv == -ERESTARTSYS) {
-			log_debug(ls, "dlm_posix_lock: wait killed %llx",
-				  (unsigned long long)number);
-			spin_lock(&ops_lock);
-			list_del(&op->list);
+	rv = wait_event_interruptible(recv_wq, (op->done != 0));
+	if (rv == -ERESTARTSYS) {
+		spin_lock(&ops_lock);
+		/* recheck under ops_lock if we got a done != 0,
+		 * if so this interrupt case should be ignored
+		 */
+		if (op->done != 0) {
 			spin_unlock(&ops_lock);
-			kfree(xop);
-			do_unlock_close(ls, number, file, fl);
-			goto out;
+			goto do_lock_wait;
 		}
-	} else {
-		rv = FILE_LOCK_DEFERRED;
+
+		op->sigint = true;
+		spin_unlock(&ops_lock);
+		log_debug(ls, "%s: wait interrupted %x %llx pid %d",
+			  __func__, ls->ls_global_id,
+			  (unsigned long long)number, op->info.pid);
 		goto out;
 	}
 
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		log_error(ls, "dlm_posix_lock: op on list %llx",
-			  (unsigned long long)number);
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
+do_lock_wait:
+
+	WARN_ON(!list_empty(&op->list));
 
 	rv = op->info.rv;
 
@@ -174,7 +187,7 @@ int dlm_posix_lock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 				  (unsigned long long)number);
 	}
 
-	kfree(xop);
+	dlm_release_plock_op(op);
 out:
 	dlm_put_lockspace(ls);
 	return rv;
@@ -184,26 +197,20 @@ EXPORT_SYMBOL_GPL(dlm_posix_lock);
 /* Returns failure iff a successful lock operation should be canceled */
 static int dlm_plock_callback(struct plock_op *op)
 {
+	struct plock_async_data *op_data = op->data;
 	struct file *file;
 	struct file_lock *fl;
 	struct file_lock *flc;
 	int (*notify)(struct file_lock *fl, int result) = NULL;
-	struct plock_xop *xop = (struct plock_xop *)op;
 	int rv = 0;
 
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		log_print("dlm_plock_callback: op on list %llx",
-			  (unsigned long long)op->info.number);
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
+	WARN_ON(!list_empty(&op->list));
 
 	/* check if the following 2 are still valid or make a copy */
-	file = xop->file;
-	flc = &xop->flc;
-	fl = xop->fl;
-	notify = xop->callback;
+	file = op_data->file;
+	flc = &op_data->flc;
+	fl = op_data->fl;
+	notify = op_data->callback;
 
 	if (op->info.rv) {
 		notify(fl, op->info.rv);
@@ -234,7 +241,7 @@ static int dlm_plock_callback(struct plock_op *op)
 	}
 
 out:
-	kfree(xop);
+	dlm_release_plock_op(op);
 	return rv;
 }
 
@@ -290,13 +297,7 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 	send_op(op);
 	wait_event(recv_wq, (op->done != 0));
 
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		log_error(ls, "dlm_posix_unlock: op on list %llx",
-			  (unsigned long long)number);
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
+	WARN_ON(!list_empty(&op->list));
 
 	rv = op->info.rv;
 
@@ -304,7 +305,7 @@ int dlm_posix_unlock(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 		rv = 0;
 
 out_free:
-	kfree(op);
+	dlm_release_plock_op(op);
 out:
 	dlm_put_lockspace(ls);
 	fl->fl_flags = fl_flags;
@@ -344,13 +345,7 @@ int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 	send_op(op);
 	wait_event(recv_wq, (op->done != 0));
 
-	spin_lock(&ops_lock);
-	if (!list_empty(&op->list)) {
-		log_error(ls, "dlm_posix_get: op on list %llx",
-			  (unsigned long long)number);
-		list_del(&op->list);
-	}
-	spin_unlock(&ops_lock);
+	WARN_ON(!list_empty(&op->list));
 
 	/* info.rv from userspace is 1 for conflict, 0 for no-conflict,
 	   -ENOENT if there are no locks on the file */
@@ -370,7 +365,7 @@ int dlm_posix_get(dlm_lockspace_t *lockspace, u64 number, struct file *file,
 		rv = 0;
 	}
 
-	kfree(op);
+	dlm_release_plock_op(op);
 out:
 	dlm_put_lockspace(ls);
 	return rv;
@@ -389,7 +384,7 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count,
 
 	spin_lock(&ops_lock);
 	if (!list_empty(&send_list)) {
-		op = list_entry(send_list.next, struct plock_op, list);
+		op = list_first_entry(&send_list, struct plock_op, list);
 		if (op->info.flags & DLM_PLOCK_FL_CLOSE)
 			list_del(&op->list);
 		else
@@ -406,7 +401,7 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count,
 	   (the process did not make an unlock call). */
 
 	if (op->info.flags & DLM_PLOCK_FL_CLOSE)
-		kfree(op);
+		dlm_release_plock_op(op);
 
 	if (copy_to_user(u, &info, sizeof(info)))
 		return -EFAULT;
@@ -418,9 +413,9 @@ static ssize_t dev_read(struct file *file, char __user *u, size_t count,
 static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
 			 loff_t *ppos)
 {
+	struct plock_op *op = NULL, *iter;
 	struct dlm_plock_info info;
-	struct plock_op *op;
-	int found = 0, do_callback = 0;
+	int do_callback = 0;
 
 	if (count != sizeof(info))
 		return -EINVAL;
@@ -432,31 +427,43 @@ static ssize_t dev_write(struct file *file, const char __user *u, size_t count,
 		return -EINVAL;
 
 	spin_lock(&ops_lock);
-	list_for_each_entry(op, &recv_list, list) {
-		if (op->info.fsid == info.fsid &&
-		    op->info.number == info.number &&
-		    op->info.owner == info.owner) {
-			struct plock_xop *xop = (struct plock_xop *)op;
-			list_del_init(&op->list);
-			memcpy(&op->info, &info, sizeof(info));
-			if (xop->callback)
+	list_for_each_entry(iter, &recv_list, list) {
+		if (iter->info.fsid == info.fsid &&
+		    iter->info.number == info.number &&
+		    iter->info.owner == info.owner) {
+			if (iter->sigint) {
+				list_del(&iter->list);
+				spin_unlock(&ops_lock);
+
+				pr_debug("%s: sigint cleanup %x %llx pid %d",
+					  __func__, iter->info.fsid,
+					  (unsigned long long)iter->info.number,
+					  iter->info.pid);
+				do_unlock_close(&iter->info);
+				memcpy(&iter->info, &info, sizeof(info));
+				dlm_release_plock_op(iter);
+				return count;
+			}
+			list_del_init(&iter->list);
+			memcpy(&iter->info, &info, sizeof(info));
+			if (iter->data)
 				do_callback = 1;
 			else
-				op->done = 1;
-			found = 1;
+				iter->done = 1;
+			op = iter;
 			break;
 		}
 	}
 	spin_unlock(&ops_lock);
 
-	if (found) {
+	if (op) {
 		if (do_callback)
 			dlm_plock_callback(op);
 		else
 			wake_up(&recv_wq);
 	} else
-		log_print("dev_write no op %x %llx", info.fsid,
-			  (unsigned long long)info.number);
+		log_print("%s: no op %x %llx", __func__,
+			  info.fsid, (unsigned long long)info.number);
 	return count;
 }
 
@@ -492,12 +499,6 @@ int dlm_plock_init(void)
 {
 	int rv;
 
-	spin_lock_init(&ops_lock);
-	INIT_LIST_HEAD(&send_list);
-	INIT_LIST_HEAD(&recv_list);
-	init_waitqueue_head(&send_wq);
-	init_waitqueue_head(&recv_wq);
-
 	rv = misc_register(&plock_dev_misc);
 	if (rv)
 		log_print("dlm_plock_init: misc_register failed %d", rv);