lockd: handle fl_grant callbacks

Add code to handle file system callback when the lock is finally granted.

Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Marc Eshel 2006-11-28 16:26:51 -05:00 committed by J. Bruce Fields
parent 2b36f412ab
commit 0e4ac9d935
1 changed files with 87 additions and 4 deletions

View File

@ -261,6 +261,7 @@ 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);
kfree(block->b_fl);
kfree(block);
}
@ -527,6 +528,64 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
return status ? nlm_lck_denied : nlm_granted;
}
/*
* This is a callback from the filesystem for VFS file lock requests.
* It will be used if fl_grant 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_TIMED_OUT;
if (conf) {
block->b_fl = kzalloc(sizeof(struct file_lock), GFP_KERNEL);
if (block->b_fl)
locks_copy_lock(block->b_fl, conf);
}
}
static int nlmsvc_grant_deferred(struct file_lock *fl, struct file_lock *conf,
int result)
{
struct nlm_block *block;
int rc = -ENOENT;
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_TIMED_OUT) {
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);
rc = 0;
break;
}
}
unlock_kernel();
if (rc == -ENOENT)
printk(KERN_WARNING "lockd: grant for unknown block\n");
return rc;
}
/*
* Unblock a blocked lock request. This is a callback invoked from the
* VFS layer when a lock on which we blocked is removed.
@ -559,6 +618,7 @@ static int nlmsvc_same_owner(struct file_lock *fl1, struct file_lock *fl2)
struct lock_manager_operations nlmsvc_lock_operations = {
.fl_compare_owner = nlmsvc_same_owner,
.fl_notify = nlmsvc_notify_blocked,
.fl_grant = nlmsvc_grant_deferred,
};
/*
@ -581,6 +641,8 @@ 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);
@ -603,11 +665,13 @@ 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;
}
@ -620,7 +684,6 @@ 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);
}
@ -693,6 +756,23 @@ 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_TIMED_OUT;
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
@ -716,9 +796,12 @@ 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;