NLM: Further cancel fixes

If the server receives an NLM cancel call and finds no waiting lock to
 cancel, then chances are the lock has already been applied, and the client
 just hadn't yet processed the NLM granted callback before it sent the
 cancel.

 The Open Group text, for example, perimts a server to return either success
 (LCK_GRANTED) or failure (LCK_DENIED) in this case.  But returning an error
 seems more helpful; the client may be able to use it to recognize that a
 race has occurred and to recover from the race.

 So, modify the relevant functions to return an error in this case.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
J. Bruce Fields
2006-01-03 09:55:46 +01:00
committed by Trond Myklebust
parent 2c5acd2e1a
commit 64a318ee2a
3 changed files with 17 additions and 7 deletions

View File

@@ -1958,13 +1958,18 @@ EXPORT_SYMBOL(posix_block_lock);
*
* lockd needs to block waiting for locks.
*/
void
int
posix_unblock_lock(struct file *filp, struct file_lock *waiter)
{
int status = 0;
lock_kernel();
if (waiter->fl_next)
__locks_delete_block(waiter);
else
status = -ENOENT;
unlock_kernel();
return status;
}
EXPORT_SYMBOL(posix_unblock_lock);