This patch is fixing the current the callback handling if a nfs async
lock request signaled if fl_lmops is set.
When using `stress-ng --fcntl 32` on the kernel log there are several
messages like:
[11185.123533] dlm: dlm_plock_callback: vfs lock error 5d5127 file 000000002dd10f4d fl 000000007d13afae
[11185.127135] dlm: dlm_plock_callback: vfs lock error 5d5127 file 000000002dd10f4d fl 00000000a6046fa0
[11185.142668] dlm: dlm_plock_callback: vfs lock error 5d5127 file 000000002dd10f4d fl 000000001d13dfa5
The commit 40595cdc93ed ("nfs: block notification on fs with its
own ->lock") removed the FL_SLEEP handling if the filesystem implements
its own ->lock. The strategy is now that the most clients polling
blocked requests by using trylock functionality.
Before commit 40595cdc93ed ("nfs: block notification on fs with its own
->lock") FL_SLEEP was used even with an own ->lock() callback. The fs
implementation needed to handle it to make a difference between a
blocking and non-blocking lock request. This was never being implemented
in such way in DLM plock handling. Every lock request doesn't matter if
it was a blocking request or not was handled as a non-blocking lock
request.
This patch fixes the behaviour until commit 40595cdc93ed ("nfs: block
notification on fs with its own ->lock"), but it was probably broken
long time before.
Fixes: 40595cdc93ed ("nfs: block notification on fs with its own ->lock")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
---
changes since v2:
- rephrase commit msg
- add cc stable
fs/dlm/plock.c | 22 +---------------------
1 file changed, 1 insertion(+), 21 deletions(-)
diff --git a/fs/dlm/plock.c b/fs/dlm/plock.c
index 70a4752ed913..6f0ecb2176b0 100644
--- a/fs/dlm/plock.c
+++ b/fs/dlm/plock.c
@@ -217,27 +217,7 @@ static int dlm_plock_callback(struct plock_op *op)
fl = op_data->fl;
notify = op_data->callback;
- if (op->info.rv) {
- notify(fl, op->info.rv);
- goto out;
- }
-
- /* got fs lock; bookkeep locally as well: */
- flc->fl_flags &= ~FL_SLEEP;
- if (posix_lock_file(file, flc, NULL)) {
- /*
- * This can only happen in the case of kmalloc() failure.
- * The filesystem's own lock is the authoritative lock,
- * so a failure to get the lock locally is not a disaster.
- * As long as the fs cannot reliably cancel locks (especially
- * in a low-memory situation), we're better off ignoring
- * this failure than trying to recover.
- */
- log_print("dlm_plock_callback: vfs lock error %llx file %p fl %p",
- (unsigned long long)op->info.number, file, fl);
- }
-
- rv = notify(fl, 0);
+ rv = notify(fl, op->info.rv);
if (rv) {
/* XXX: We need to cancel the fs lock here: */
log_print("dlm_plock_callback: lock granted after lock request "
--
2.31.1
