gfs2: Clear flags when withdraw prevents xmote

There are a couple places in function do_xmote where normal processing
is circumvented due to withdraws in progress. However, since we bypass
most of do_xmote() we bypass telling dlm to lock the dlm lock, which
means dlm will never respond with a completion callback. Since the
completion callback ordinarily clears GLF_LOCK, this patch changes
function do_xmote to handle those situations more gracefully so the
file system may be unmounted after withdraw.

A very similar situation happens with the GLF_DEMOTE_IN_PROGRESS flag,
which is cleared by function finish_xmote(). Since the withdraw causes
us to skip the majority of do_xmote, it therefore also skips the call
to finish_xmote() so the DEMOTE_IN_PROGRESS flag needs to be cleared
manually.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This commit is contained in:
Bob Peterson 2022-08-18 13:32:38 -05:00 committed by Andreas Gruenbacher
parent 053640a738
commit 86934198ee

View file

@ -59,6 +59,8 @@ typedef void (*glock_examiner) (struct gfs2_glock * gl);
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target);
static void __gfs2_glock_dq(struct gfs2_holder *gh);
static void handle_callback(struct gfs2_glock *gl, unsigned int state,
unsigned long delay, bool remote);
static struct dentry *gfs2_root;
static struct workqueue_struct *glock_workqueue;
@ -730,7 +732,8 @@ static bool is_system_glock(struct gfs2_glock *gl)
*
*/
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target)
static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh,
unsigned int target)
__releases(&gl->gl_lockref.lock)
__acquires(&gl->gl_lockref.lock)
{
@ -741,7 +744,8 @@ __acquires(&gl->gl_lockref.lock)
if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) &&
gh && !(gh->gh_flags & LM_FLAG_NOEXP))
return;
goto skip_inval;
lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP |
LM_FLAG_PRIORITY);
GLOCK_BUG_ON(gl, gl->gl_state == target);
@ -826,6 +830,20 @@ __acquires(&gl->gl_lockref.lock)
(target != LM_ST_UNLOCKED ||
test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags))) {
if (!is_system_glock(gl)) {
handle_callback(gl, LM_ST_UNLOCKED, 0, false); /* sets demote */
/*
* Ordinarily, we would call dlm and its callback would call
* finish_xmote, which would call state_change() to the new state.
* Since we withdrew, we won't call dlm, so call state_change
* manually, but to the UNLOCKED state we desire.
*/
state_change(gl, LM_ST_UNLOCKED);
/*
* We skip telling dlm to do the locking, so we won't get a
* reply that would otherwise clear GLF_LOCK. So we clear it here.
*/
clear_bit(GLF_LOCK, &gl->gl_flags);
clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags);
gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD);
goto out;
} else {