GFS2: Adjust lock reference count
A message that is not in the archive (sent off-list or not yet received): [email protected]
PATCH 1/1 GFS2: Adjust lock reference count
Hi,
This patch closes a small timing window whereby a request to hold the transaction glock can get stuck. The problem is that after the DLM has granted the lock, it can get into a state whereby it doesn't transition the glock to a held state, due to not having requeued the glock state machine to finish the transition.
Steve: Feel free to adjust the patch description as you see fit. I'm not feeling very creative at the moment.
Regards,
Bob Peterson
Red Hat File Systems
--- fs/gfs2/glock.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
fs/gfs2/glock.c +6 -2
@@ -1047,9 +1047,13 @@ int gfs2_glock_nq(struct gfs2_holder *gh)spin_lock (&gl->gl_spin);add_to_queue (gh); -if ((LM_FLAG_NOEXP & gh->gh_flags) && -test_and_clear_bit (GLF_FROZEN , &gl->gl_flags)) +if (unlikely ((LM_FLAG_NOEXP & gh->gh_flags) && +test_and_clear_bit (GLF_FROZEN , &gl->gl_flags))) {set_bit (GLF_REPLY_PENDING , &gl->gl_flags); +atomic_inc (&gl->gl_ref); +if (queue_delayed_work (glock_workqueue, &gl->gl_work,0 ) ==0 ) +atomic_dec (&gl->gl_ref); + }run_queue (gl,1 );spin_unlock (&gl->gl_spin);
PATCH 1/1 GFS2: Adjust lock reference count
Hi,
Quoted 8 lines · Bob Peterson
Hi,
This patch closes a small timing window whereby a request to hold the transaction glock can get stuck. The problem is that after the DLM has granted the lock, it can get into a state whereby it doesn't transition the glock to a held state, due to not having requeued the glock state machine to finish the transition.
Quoted 8 lines
Steve: Feel free to adjust the patch description as you see fit. I'm not feeling very creative at the moment.
Regards,
Bob Peterson
Red Hat File Systems
I updated the description, and also converted the atomic_inc to lockref
- I guess that you didn't compile test this one. Anyway, that should sort it out I think, so I've added it to the tree now, since we know that the fix is needed,
Steve.
Quoted 26 lines
Signed-off-by Bob Peterson <[email protected]>--- fs/gfs2/glock.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)fs/gfs2/glock.c +6
-2@@ -1047,9 +1047,13 @@ int gfs2_glock_nq(struct gfs2_holder *gh)spin_lock (&gl->gl_spin);add_to_queue (gh); -if ((LM_FLAG_NOEXP & gh->gh_flags) && -test_and_clear_bit (GLF_FROZEN , &gl->gl_flags)) +if (unlikely ((LM_FLAG_NOEXP & gh->gh_flags) && +test_and_clear_bit (GLF_FROZEN , &gl->gl_flags))) {set_bit (GLF_REPLY_PENDING , &gl->gl_flags); +atomic_inc (&gl->gl_ref); +if (queue_delayed_work (glock_workqueue, &gl->gl_work,0 ) ==0 ) +atomic_dec (&gl->gl_ref); + }run_queue (gl,1 );spin_unlock (&gl->gl_spin);