From: Marc Eshel <eshel@xxxxxxxxxxxxxxx> - unquoted
Add code to handle file system callback when the lock is finally granted.
Signed-off-by: Marc Eshel <eshel@xxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
---
fs/lockd/svclock.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 74 insertions(+), 6 deletions(-)
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index f8e2aeb..cd5b7d3 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -261,6 +261,8 @@ static void nlmsvc_free_block(struct kref *kref)
nlmsvc_freegrantargs(block->b_call);
nlm_release_call(block->b_call);
nlm_release_file(block->b_file);
+ if (block->b_fl)
+ kfree(block->b_fl);
kfree(block);
}
@@ -528,6 +530,32 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
}
/*
+ * This is a callback from the filesystem for VFS file lock requests.
+ * It will be used if fl_notify is defined and the filesystem can not
+ * respond to the request immediately.
+ * For GETLK request it will copy the reply to the nlm_block.
+ * For SETLK or SETLKW request it will get the local posix lock.
+ * In all cases it will move the block to the head of nlm_blocked q where
+ * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
+ * deferred rpc for GETLK and SETLK.
+ */
+static void
+nlmsvc_update_deferred_block(struct nlm_block *block, struct file_lock *conf,
+ int result)
+{
+ block->b_flags |= B_GOT_CALLBACK;
+ if (result == 0)
+ block->b_granted = 1;
+ else
+ block->b_flags |= B_TOO_LATE;
+ if (conf) {
+ block->b_fl = kzalloc(sizeof(struct file_lock), GFP_KERNEL);
+ if (block->b_fl)
+ locks_copy_lock(block->b_fl, conf);
+ }
+}
+
+/*
* Unblock a blocked lock request. This is a callback invoked from the
* VFS layer when a lock on which we blocked is removed.
*
@@ -538,18 +566,35 @@ static int
nlmsvc_notify_blocked(struct file_lock *fl, struct file_lock *conf, int result)
{
struct nlm_block *block;
+ int rc = -ENOENT;
dprintk("lockd: nlmsvc_notify_blocked lock %p conf %p result %d\n",
fl, conf, result);
+ lock_kernel();
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",
+ block, block->b_flags);
+ if (block->b_flags & B_QUEUED) {
+ if (block->b_flags & B_TOO_LATE) {
+ rc = -ENOLCK;
+ break;
+ }
+ nlmsvc_update_deferred_block(block, conf, result);
+ } else if (result == 0)
+ block->b_granted = 1;
+
nlmsvc_insert_block(block, 0);
svc_wake_up(block->b_daemon);
- return;
+ rc = 0;
+ break;
}
}
+ unlock_kernel();
- printk(KERN_WARNING "lockd: notification for unknown block!\n");
+ if (rc == -ENOENT)
+ printk(KERN_WARNING "lockd: notification for unknown block!\n");
+ return rc;
}
static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
@@ -582,6 +627,8 @@ nlmsvc_grant_blocked(struct nlm_block *block)
dprintk("lockd: grant blocked lock %p\n", block);
+ kref_get(&block->b_count);
+
/* Unlink block request from list */
nlmsvc_unlink_block(block);
@@ -604,11 +651,13 @@ nlmsvc_grant_blocked(struct nlm_block *block)
case -EAGAIN:
dprintk("lockd: lock still blocked\n");
nlmsvc_insert_block(block, NLM_NEVER);
+ nlmsvc_release_block(block);
return;
default:
printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
-error, __FUNCTION__);
nlmsvc_insert_block(block, 10 * HZ);
+ nlmsvc_release_block(block);
return;
}
@@ -621,7 +670,6 @@ callback:
nlmsvc_insert_block(block, 30 * HZ);
/* Call the client */
- kref_get(&block->b_count);
nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG, &nlmsvc_grant_ops);
}
@@ -694,6 +742,23 @@ nlmsvc_grant_reply(struct nlm_cookie *cookie, __be32 status)
nlmsvc_release_block(block);
}
+/* Helper function to handle retry of a deferred block.
+ * If it is a blocking lock, call grant_blocked.
+ * For a non-blocking lock or test lock, revisit the request.
+ */
+static void
+retry_deferred_block(struct nlm_block *block)
+{
+ if (!(block->b_flags & B_GOT_CALLBACK))
+ block->b_flags |= B_TOO_LATE;
+ nlmsvc_insert_block(block, NLM_TIMEOUT);
+ dprintk("revisit block %p flags %d\n", block, block->b_flags);
+ if (block->b_deferred_req) {
+ block->b_deferred_req->revisit(block->b_deferred_req, 0);
+ block->b_deferred_req = NULL;
+ }
+}
+
/*
* Retry all blocked locks that have been notified. This is where lockd
* picks up locks that can be granted, or grant notifications that must
@@ -717,9 +782,12 @@ nlmsvc_retry_blocked(void)
dprintk("nlmsvc_retry_blocked(%p, when=%ld)\n",
block, block->b_when);
- kref_get(&block->b_count);
- nlmsvc_grant_blocked(block);
- nlmsvc_release_block(block);
+ if (block->b_flags & B_QUEUED) {
+ dprintk("nlmsvc_retry_blocked delete block (%p, granted=%d, flags=%d)\n",
+ block, block->b_granted, block->b_flags);
+ retry_deferred_block(block);
+ } else
+ nlmsvc_grant_blocked(block);
}
return timeout;
--
1.5.0.rc1.gf4b6c
-
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