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-rw-r--r--fs/gfs2/glock.c248
1 files changed, 105 insertions, 143 deletions
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 4ddf3bd..07ffc81 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -62,9 +62,10 @@ static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int
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;
+static LIST_HEAD(lru_list);
+static atomic_t lru_count = ATOMIC_INIT(0);
+static spinlock_t lru_lock = SPIN_LOCK_UNLOCKED;
#define GFS2_GL_HASH_SHIFT 15
#define GFS2_GL_HASH_SIZE (1 << GFS2_GL_HASH_SHIFT)
@@ -175,6 +176,22 @@ static void gfs2_glock_hold(struct gfs2_glock *gl)
}
/**
+ * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
+ * @gl: the glock
+ *
+ */
+
+static void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
+{
+ spin_lock(&lru_lock);
+ if (list_empty(&gl->gl_lru) && gl->gl_state != LM_ST_UNLOCKED) {
+ list_add_tail(&gl->gl_lru, &lru_list);
+ atomic_inc(&lru_count);
+ }
+ spin_unlock(&lru_lock);
+}
+
+/**
* gfs2_glock_put() - Decrement reference count on glock
* @gl: The glock to put
*
@@ -188,14 +205,23 @@ int gfs2_glock_put(struct gfs2_glock *gl)
if (atomic_dec_and_test(&gl->gl_ref)) {
hlist_del(&gl->gl_list);
write_unlock(gl_lock_addr(gl->gl_hash));
+ spin_lock(&lru_lock);
+ if (!list_empty(&gl->gl_lru)) {
+ list_del_init(&gl->gl_lru);
+ atomic_dec(&lru_count);
+ }
+ spin_unlock(&lru_lock);
GLOCK_BUG_ON(gl, gl->gl_state != LM_ST_UNLOCKED);
- GLOCK_BUG_ON(gl, !list_empty(&gl->gl_reclaim));
+ GLOCK_BUG_ON(gl, !list_empty(&gl->gl_lru));
GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders));
glock_free(gl);
rv = 1;
goto out;
}
write_unlock(gl_lock_addr(gl->gl_hash));
+ /* 1 for being hashed, 1 for having state != LM_ST_UNLOCKED */
+ if (atomic_read(&gl->gl_ref) == 2)
+ gfs2_glock_schedule_for_reclaim(gl);
out:
return rv;
}
@@ -837,7 +863,7 @@ static void wait_on_demote(struct gfs2_glock *gl)
*/
static void handle_callback(struct gfs2_glock *gl, unsigned int state,
- int remote, unsigned long delay)
+ unsigned long delay)
{
int bit = delay ? GLF_PENDING_DEMOTE : GLF_DEMOTE;
@@ -845,9 +871,6 @@ static void handle_callback(struct gfs2_glock *gl, unsigned int state,
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 &&
- gl->gl_object)
- gfs2_glock_schedule_for_reclaim(gl);
} else if (gl->gl_demote_state != LM_ST_UNLOCKED &&
gl->gl_demote_state != state) {
gl->gl_demote_state = LM_ST_UNLOCKED;
@@ -1017,7 +1040,7 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
spin_lock(&gl->gl_spin);
if (gh->gh_flags & GL_NOCACHE)
- handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
+ handle_callback(gl, LM_ST_UNLOCKED, 0);
list_del_init(&gh->gh_list);
if (find_first_holder(gl) == NULL) {
@@ -1288,7 +1311,7 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
delay = gl->gl_ops->go_min_hold_time;
spin_lock(&gl->gl_spin);
- handle_callback(gl, state, 1, delay);
+ handle_callback(gl, state, delay);
spin_unlock(&gl->gl_spin);
if (queue_delayed_work(glock_workqueue, &gl->gl_work, delay) == 0)
gfs2_glock_put(gl);
@@ -1357,80 +1380,83 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
* Returns: 1 if it's ok
*/
-static int demote_ok(struct gfs2_glock *gl)
+static int demote_ok(const struct gfs2_glock *gl)
{
const struct gfs2_glock_operations *glops = gl->gl_ops;
- int demote = 1;
-
- if (test_bit(GLF_STICKY, &gl->gl_flags))
- demote = 0;
- else if (glops->go_demote_ok)
- demote = glops->go_demote_ok(gl);
-
- return demote;
-}
-/**
- * gfs2_glock_schedule_for_reclaim - Add a glock to the reclaim list
- * @gl: the glock
- *
- */
-
-void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl)
-{
- struct gfs2_sbd *sdp = gl->gl_sbd;
-
- spin_lock(&sdp->sd_reclaim_lock);
- if (list_empty(&gl->gl_reclaim)) {
- gfs2_glock_hold(gl);
- list_add(&gl->gl_reclaim, &sdp->sd_reclaim_list);
- atomic_inc(&sdp->sd_reclaim_count);
- spin_unlock(&sdp->sd_reclaim_lock);
- wake_up(&sdp->sd_reclaim_wq);
- } else
- spin_unlock(&sdp->sd_reclaim_lock);
+ if (gl->gl_state == LM_ST_UNLOCKED)
+ return 0;
+ if (!list_empty(&gl->gl_holders))
+ return 0;
+ if (glops->go_demote_ok)
+ return glops->go_demote_ok(gl);
+ return 1;
}
-/**
- * gfs2_reclaim_glock - process the next glock on the filesystem's reclaim list
- * @sdp: the filesystem
- *
- * Called from gfs2_glockd() glock reclaim daemon, or when promoting a
- * different glock and we notice that there are a lot of glocks in the
- * reclaim list.
- *
- */
-void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
+static int gfs2_shrink_glock_memory(int nr, gfp_t gfp_mask)
{
struct gfs2_glock *gl;
- int done_callback = 0;
+ int may_demote;
+ int nr_skipped = 0;
+ int got_ref = 0;
+ LIST_HEAD(skipped);
- spin_lock(&sdp->sd_reclaim_lock);
- if (list_empty(&sdp->sd_reclaim_list)) {
- spin_unlock(&sdp->sd_reclaim_lock);
- return;
- }
- gl = list_entry(sdp->sd_reclaim_list.next,
- struct gfs2_glock, gl_reclaim);
- list_del_init(&gl->gl_reclaim);
- spin_unlock(&sdp->sd_reclaim_lock);
+ if (nr == 0)
+ goto out;
- atomic_dec(&sdp->sd_reclaim_count);
- atomic_inc(&sdp->sd_reclaimed);
+ if (!(gfp_mask & __GFP_FS))
+ return -1;
- spin_lock(&gl->gl_spin);
- if (find_first_holder(gl) == NULL &&
- gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl)) {
- handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
- done_callback = 1;
+ spin_lock(&lru_lock);
+ while(nr && !list_empty(&lru_list)) {
+ gl = list_entry(lru_list.next, struct gfs2_glock, gl_lru);
+ list_del_init(&gl->gl_lru);
+ atomic_dec(&lru_count);
+
+ /* Test for being demotable */
+ if (!test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
+ gfs2_glock_hold(gl);
+ got_ref = 1;
+ spin_unlock(&lru_lock);
+ spin_lock(&gl->gl_spin);
+ may_demote = demote_ok(gl);
+ spin_unlock(&gl->gl_spin);
+ clear_bit(GLF_LOCK, &gl->gl_flags);
+ if (may_demote) {
+ handle_callback(gl, LM_ST_UNLOCKED, 0);
+ nr--;
+ if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
+ gfs2_glock_put(gl);
+ }
+ spin_lock(&lru_lock);
+ if (may_demote)
+ continue;
+ }
+ if (list_empty(&gl->gl_lru) &&
+ (atomic_read(&gl->gl_ref) <= (2 + got_ref))) {
+ nr_skipped++;
+ list_add(&gl->gl_lru, &skipped);
+ }
+ if (got_ref) {
+ spin_unlock(&lru_lock);
+ gfs2_glock_put(gl);
+ spin_lock(&lru_lock);
+ got_ref = 0;
+ }
}
- spin_unlock(&gl->gl_spin);
- if (!done_callback ||
- queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
- gfs2_glock_put(gl);
+ list_splice(&skipped, &lru_list);
+ atomic_add(nr_skipped, &lru_count);
+ spin_unlock(&lru_lock);
+out:
+ return (atomic_read(&lru_count) / 100) * sysctl_vfs_cache_pressure;
}
+static struct shrinker glock_shrinker = {
+ .shrink = gfs2_shrink_glock_memory,
+ .seeks = DEFAULT_SEEKS,
+};
+
/**
* examine_bucket - Call a function for glock in a hash bucket
* @examiner: the function
@@ -1476,26 +1502,6 @@ out:
}
/**
- * scan_glock - look at a glock and see if we can reclaim it
- * @gl: the glock to look at
- *
- */
-
-static void scan_glock(struct gfs2_glock *gl)
-{
- if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
- return;
- if (test_bit(GLF_LOCK, &gl->gl_flags))
- return;
-
- spin_lock(&gl->gl_spin);
- if (find_first_holder(gl) == NULL &&
- gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
- gfs2_glock_schedule_for_reclaim(gl);
- spin_unlock(&gl->gl_spin);
-}
-
-/**
* clear_glock - look at a glock and see if we can free it from glock cache
* @gl: the glock to look at
*
@@ -1503,23 +1509,16 @@ static void scan_glock(struct gfs2_glock *gl)
static void clear_glock(struct gfs2_glock *gl)
{
- struct gfs2_sbd *sdp = gl->gl_sbd;
- int released;
-
- spin_lock(&sdp->sd_reclaim_lock);
- if (!list_empty(&gl->gl_reclaim)) {
- list_del_init(&gl->gl_reclaim);
- atomic_dec(&sdp->sd_reclaim_count);
- spin_unlock(&sdp->sd_reclaim_lock);
- released = gfs2_glock_put(gl);
- gfs2_assert(sdp, !released);
- } else {
- spin_unlock(&sdp->sd_reclaim_lock);
+ spin_lock(&lru_lock);
+ if (!list_empty(&gl->gl_lru)) {
+ list_del_init(&gl->gl_lru);
+ atomic_dec(&lru_count);
}
+ spin_unlock(&lru_lock);
spin_lock(&gl->gl_spin);
if (find_first_holder(gl) == NULL && gl->gl_state != LM_ST_UNLOCKED)
- handle_callback(gl, LM_ST_UNLOCKED, 0, 0);
+ handle_callback(gl, LM_ST_UNLOCKED, 0);
spin_unlock(&gl->gl_spin);
gfs2_glock_hold(gl);
if (queue_delayed_work(glock_workqueue, &gl->gl_work, 0) == 0)
@@ -1656,8 +1655,6 @@ static const char *gflags2str(char *buf, const unsigned long *gflags)
char *p = buf;
if (test_bit(GLF_LOCK, gflags))
*p++ = 'l';
- if (test_bit(GLF_STICKY, gflags))
- *p++ = 's';
if (test_bit(GLF_DEMOTE, gflags))
*p++ = 'D';
if (test_bit(GLF_PENDING_DEMOTE, gflags))
@@ -1776,34 +1773,6 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
return error;
}
-/**
- * gfs2_scand - Look for cached glocks and inodes to toss from memory
- * @sdp: Pointer to GFS2 superblock
- *
- * One of these daemons runs, finding candidates to add to sd_reclaim_list.
- * See gfs2_glockd()
- */
-
-static int gfs2_scand(void *data)
-{
- unsigned x;
- unsigned delay;
-
- while (!kthread_should_stop()) {
- for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
- examine_bucket(scan_glock, NULL, x);
- if (freezing(current))
- refrigerator();
- delay = scand_secs;
- if (delay < 1)
- delay = 1;
- schedule_timeout_interruptible(delay * HZ);
- }
-
- return 0;
-}
-
-
int __init gfs2_glock_init(void)
{
@@ -1817,28 +1786,21 @@ int __init gfs2_glock_init(void)
}
#endif
- scand_process = kthread_run(gfs2_scand, NULL, "gfs2_scand");
- 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);
+ if (IS_ERR(glock_workqueue))
return PTR_ERR(glock_workqueue);
- }
+
+ register_shrinker(&glock_shrinker);
return 0;
}
void gfs2_glock_exit(void)
{
+ unregister_shrinker(&glock_shrinker);
destroy_workqueue(glock_workqueue);
- kthread_stop(scand_process);
}
-module_param(scand_secs, uint, S_IRUGO|S_IWUSR);
-MODULE_PARM_DESC(scand_secs, "The number of seconds between scand runs");
-
static int gfs2_glock_iter_next(struct gfs2_glock_iter *gi)
{
struct gfs2_glock *gl;
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