Commit 86934198 authored by Bob Peterson's avatar Bob Peterson Committed by Andreas Gruenbacher
Browse files

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: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
parent 053640a7

fs/gfs2/glock.c

+20 −2
Original line number Diff line number Diff line
@@ -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 {