Attachment 162049 Details for Bug 253768 – Attempt to solve the bug

[patch] Attempt to solve the bug

glock-wq-fix.diff (text/plain), 8.36 KB, created by Steve Whitehouse on 2007-08-22 13:10:29 UTC

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Creator: Steve Whitehouse

Created: 2007-08-22 13:10:29 UTC

Size: 8.36 KB

patch

obsolete

>diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
>index 3d94918..021237d 100644
>--- a/fs/gfs2/glock.c
>+++ b/fs/gfs2/glock.c
>@@ -27,6 +27,8 @@
> #include <linux/debugfs.h>
> #include <linux/kthread.h>
> #include <linux/freezer.h>
>+#include <linux/workqueue.h>
>+#include <linux/jiffies.h>
> 
> #include "gfs2.h"
> #include "incore.h"
>@@ -58,10 +60,13 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
> static int dump_glock(struct glock_iter *gi, struct gfs2_glock *gl);
> static void gfs2_glock_xmote_th(struct gfs2_glock *gl, struct gfs2_holder *gh);
> static void gfs2_glock_drop_th(struct gfs2_glock *gl);
>+static void run_queue(struct gfs2_glock *gl);
>+
> static DECLARE_RWSEM(gfs2_umount_flush_sem);
> static struct dentry *gfs2_root;
> static struct task_struct *scand_process;
> static unsigned int scand_secs = 5;
>+static struct workqueue_struct *glock_workqueue;
> 
> #define GFS2_GL_HASH_SHIFT      15
> #define GFS2_GL_HASH_SIZE       (1 << GFS2_GL_HASH_SHIFT)
>@@ -277,6 +282,18 @@ static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
> 	return gl;
> }
> 
>+static void glock_work_func(struct work_struct *work)
>+{
>+	struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work);
>+
>+	spin_lock(&gl->gl_spin);
>+	if (test_and_clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags))
>+		set_bit(GLF_DEMOTE, &gl->gl_flags);
>+	run_queue(gl);
>+	spin_unlock(&gl->gl_spin);
>+	gfs2_glock_put(gl);
>+}
>+
> /**
>  * gfs2_glock_get() - Get a glock, or create one if one doesn't exist
>  * @sdp: The GFS2 superblock
>@@ -316,6 +333,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
> 	gl->gl_name = name;
> 	atomic_set(&gl->gl_ref, 1);
> 	gl->gl_state = LM_ST_UNLOCKED;
>+	gl->gl_demote_state = LM_ST_EXCLUSIVE;
> 	gl->gl_hash = hash;
> 	gl->gl_owner_pid = 0;
> 	gl->gl_ip = 0;
>@@ -324,10 +342,12 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
> 	gl->gl_req_bh = NULL;
> 	gl->gl_vn = 0;
> 	gl->gl_stamp = jiffies;
>+	gl->gl_tchange = jiffies;
> 	gl->gl_object = NULL;
> 	gl->gl_sbd = sdp;
> 	gl->gl_aspace = NULL;
> 	lops_init_le(&gl->gl_le, &gfs2_glock_lops);
>+	INIT_DELAYED_WORK(&gl->gl_work, glock_work_func);
> 
> 	/* If this glock protects actual on-disk data or metadata blocks,
> 	   create a VFS inode to manage the pages/buffers holding them. */
>@@ -441,6 +461,8 @@ static void wait_on_holder(struct gfs2_holder *gh)
> 
> static void gfs2_demote_wake(struct gfs2_glock *gl)
> {
>+	BUG_ON(!spin_is_locked(&gl->gl_spin));
>+	gl->gl_demote_state = LM_ST_EXCLUSIVE;
>         clear_bit(GLF_DEMOTE, &gl->gl_flags);
>         smp_mb__after_clear_bit();
>         wake_up_bit(&gl->gl_flags, GLF_DEMOTE);
>@@ -682,10 +704,14 @@ static void gfs2_glmutex_unlock(struct gfs2_glock *gl)
>  * practise: LM_ST_SHARED and LM_ST_UNLOCKED
>  */
> 
>-static void handle_callback(struct gfs2_glock *gl, unsigned int state, int remote)
>+static void handle_callback(struct gfs2_glock *gl, unsigned int state,
>+			    int remote, unsigned long delay)
> {
>+	int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
>+
> 	spin_lock(&gl->gl_spin);
>-	if (test_and_set_bit(GLF_DEMOTE, &gl->gl_flags) == 0) {
>+	set_bit(bit, &gl->gl_flags);
>+	if (gl->gl_demote_state == LM_ST_EXCLUSIVE) {
> 		gl->gl_demote_state = state;
> 		gl->gl_demote_time = jiffies;
> 		if (remote && gl->gl_ops->go_type == LM_TYPE_IOPEN &&
>@@ -727,6 +753,7 @@ static void state_change(struct gfs2_glock *gl, unsigned int new_state)
> 	}
> 
> 	gl->gl_state = new_state;
>+	gl->gl_tchange = jiffies;
> }
> 
> /**
>@@ -813,7 +840,6 @@ out:
> 		gl->gl_req_gh = NULL;
> 		gl->gl_req_bh = NULL;
> 		clear_bit(GLF_LOCK, &gl->gl_flags);
>-		run_queue(gl);
> 		spin_unlock(&gl->gl_spin);
> 	}
> 
>@@ -885,7 +911,6 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
> 	gfs2_assert_warn(sdp, !ret);
> 
> 	state_change(gl, LM_ST_UNLOCKED);
>-	gfs2_demote_wake(gl);
> 
> 	if (glops->go_inval)
> 		glops->go_inval(gl, DIO_METADATA);
>@@ -898,10 +923,10 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
> 	}
> 
> 	spin_lock(&gl->gl_spin);
>+	gfs2_demote_wake(gl);
> 	gl->gl_req_gh = NULL;
> 	gl->gl_req_bh = NULL;
> 	clear_bit(GLF_LOCK, &gl->gl_flags);
>-	run_queue(gl);
> 	spin_unlock(&gl->gl_spin);
> 
> 	gfs2_glock_put(gl);
>@@ -1209,9 +1234,10 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
> {
> 	struct gfs2_glock *gl = gh->gh_gl;
> 	const struct gfs2_glock_operations *glops = gl->gl_ops;
>+	unsigned delay = 0;
> 
> 	if (gh->gh_flags & GL_NOCACHE)
>-		handle_callback(gl, LM_ST_UNLOCKED, 0);
>+		handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
> 
> 	gfs2_glmutex_lock(gl);
> 
>@@ -1229,8 +1255,12 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
> 	}
> 
> 	clear_bit(GLF_LOCK, &gl->gl_flags);
>-	run_queue(gl);
> 	spin_unlock(&gl->gl_spin);
>+
>+	if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) &&
>+	    !test_bit(GLF_DEMOTE, &gl->gl_flags))
>+		delay = gl->gl_ops->go_min_hold_time;
>+	queue_delayed_work(glock_workqueue, &gl->gl_work, delay);
> }
> 
> void gfs2_glock_dq_wait(struct gfs2_holder *gh)
>@@ -1457,18 +1487,21 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
> 			unsigned int state)
> {
> 	struct gfs2_glock *gl;
>+	unsigned long delay = 0;
>+	unsigned long holdtime;
>+	unsigned long now = jiffies;
> 
> 	gl = gfs2_glock_find(sdp, name);
> 	if (!gl)
> 		return;
> 
>-	handle_callback(gl, state, 1);
>-
>-	spin_lock(&gl->gl_spin);
>-	run_queue(gl);
>-	spin_unlock(&gl->gl_spin);
>+	holdtime = gl->gl_tchange + gl->gl_ops->go_min_hold_time;
>+	if (time_before(now, holdtime))
>+		delay = holdtime - now;
> 
>-	gfs2_glock_put(gl);
>+	handle_callback(gl, state, 1, delay);
>+	if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
>+		gfs2_glock_put(gl);
> }
> 
> /**
>@@ -1509,7 +1542,8 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
> 			return;
> 		if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
> 			gl->gl_req_bh(gl, async->lc_ret);
>-		gfs2_glock_put(gl);
>+		if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
>+			gfs2_glock_put(gl);
> 		up_read(&gfs2_umount_flush_sem);
> 		return;
> 	}
>@@ -1602,7 +1636,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
> 	if (gfs2_glmutex_trylock(gl)) {
> 		if (list_empty(&gl->gl_holders) &&
> 		    gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
>-			handle_callback(gl, LM_ST_UNLOCKED, 0);
>+			handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
> 		gfs2_glmutex_unlock(gl);
> 	}
> 
>@@ -1702,7 +1736,7 @@ static void clear_glock(struct gfs2_glock *gl)
> 	if (gfs2_glmutex_trylock(gl)) {
> 		if (list_empty(&gl->gl_holders) &&
> 		    gl->gl_state != LM_ST_UNLOCKED)
>-			handle_callback(gl, LM_ST_UNLOCKED, 0);
>+			handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
> 		gfs2_glmutex_unlock(gl);
> 	}
> }
>@@ -2009,11 +2043,18 @@ int __init gfs2_glock_init(void)
> 	if (IS_ERR(scand_process))
> 		return PTR_ERR(scand_process);
> 
>+	glock_workqueue = create_workqueue("glock_workqueue");
>+	if (IS_ERR(glock_workqueue)) {
>+		kthread_stop(scand_process);
>+		return PTR_ERR(glock_workqueue);
>+	}
>+
> 	return 0;
> }
> 
> void gfs2_glock_exit(void)
> {
>+	destroy_workqueue(glock_workqueue);
> 	kthread_stop(scand_process);
> }
> 
>diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
>index 88342e0..7ef6b23 100644
>--- a/fs/gfs2/glops.c
>+++ b/fs/gfs2/glops.c
>@@ -454,6 +454,7 @@ const struct gfs2_glock_operations gfs2_inode_glops = {
> 	.go_lock = inode_go_lock,
> 	.go_unlock = inode_go_unlock,
> 	.go_type = LM_TYPE_INODE,
>+	.go_min_hold_time = HZ / 10,
> };
> 
> const struct gfs2_glock_operations gfs2_rgrp_glops = {
>@@ -464,6 +465,7 @@ const struct gfs2_glock_operations gfs2_rgrp_glops = {
> 	.go_lock = rgrp_go_lock,
> 	.go_unlock = rgrp_go_unlock,
> 	.go_type = LM_TYPE_RGRP,
>+	.go_min_hold_time = HZ / 10,
> };
> 
> const struct gfs2_glock_operations gfs2_trans_glops = {
>diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
>index 1390b30..23b611a 100644
>--- a/fs/gfs2/incore.h
>+++ b/fs/gfs2/incore.h
>@@ -11,6 +11,7 @@
> #define __INCORE_DOT_H__
> 
> #include <linux/fs.h>
>+#include <linux/workqueue.h>
> 
> #define DIO_WAIT	0x00000010
> #define DIO_METADATA	0x00000020
>@@ -130,6 +131,7 @@ struct gfs2_glock_operations {
> 	int (*go_lock) (struct gfs2_holder *gh);
> 	void (*go_unlock) (struct gfs2_holder *gh);
> 	const int go_type;
>+	const unsigned long go_min_hold_time;
> };
> 
> enum {
>@@ -161,6 +163,7 @@ enum {
> 	GLF_LOCK		= 1,
> 	GLF_STICKY		= 2,
> 	GLF_DEMOTE		= 3,
>+	GLF_PENDING_DEMOTE	= 4,
> 	GLF_DIRTY		= 5,
> };
> 
>@@ -193,6 +196,7 @@ struct gfs2_glock {
> 
> 	u64 gl_vn;
> 	unsigned long gl_stamp;
>+	unsigned long gl_tchange;
> 	void *gl_object;
> 
> 	struct list_head gl_reclaim;
>@@ -203,6 +207,7 @@ struct gfs2_glock {
> 	struct gfs2_log_element gl_le;
> 	struct list_head gl_ail_list;
> 	atomic_t gl_ail_count;
>+	struct delayed_work gl_work;
> };
> 
> struct gfs2_alloc {

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Attachments on bug 253768: 162049 | 164161