GFS2: change gfs2_quota_scan into a shrinker

Deallocation of gfs2_quota_data objects now happens on-demand through a
shrinker instead of routinely deallocating through the quotad daemon.

Signed-off-by: Abhijith Das <adas@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/incore.h

@@ -283,7 +283,9 @@ enum {
 
 struct gfs2_quota_data {
 	struct list_head qd_list;
-	unsigned int qd_count;
+	struct list_head qd_reclaim;
+
+	atomic_t qd_count;
 
 	u32 qd_id;
 	unsigned long qd_flags;		/* QDF_... */
@@ -303,7 +305,6 @@ struct gfs2_quota_data {
 
 	u64 qd_sync_gen;
 	unsigned long qd_last_warn;
-	unsigned long qd_last_touched;
 };
 
 struct gfs2_trans {
@@ -406,7 +407,6 @@ struct gfs2_tune {
 	unsigned int gt_quota_warn_period; /* Secs between quota warn msgs */
 	unsigned int gt_quota_scale_num; /* Numerator */
 	unsigned int gt_quota_scale_den; /* Denominator */
-	unsigned int gt_quota_cache_secs;
 	unsigned int gt_quota_quantum; /* Secs between syncs to quota file */
 	unsigned int gt_new_files_jdata;
 	unsigned int gt_max_readahead; /* Max bytes to read-ahead from disk */

fs/gfs2/main.c

@@ -23,6 +23,12 @@
 #include "sys.h"
 #include "util.h"
 #include "glock.h"
+#include "quota.h"
+
+static struct shrinker qd_shrinker = {
+	.shrink = gfs2_shrink_qd_memory,
+	.seeks = DEFAULT_SEEKS,
+};
 
 static void gfs2_init_inode_once(void *foo)
 {
@@ -100,6 +106,8 @@ static int __init init_gfs2_fs(void)
 	if (!gfs2_quotad_cachep)
 		goto fail;
 
+	register_shrinker(&qd_shrinker);
+
 	error = register_filesystem(&gfs2_fs_type);
 	if (error)
 		goto fail;
@@ -117,6 +125,7 @@ static int __init init_gfs2_fs(void)
 fail_unregister:
 	unregister_filesystem(&gfs2_fs_type);
 fail:
+	unregister_shrinker(&qd_shrinker);
 	gfs2_glock_exit();
 
 	if (gfs2_quotad_cachep)
@@ -145,6 +154,7 @@ static int __init init_gfs2_fs(void)
 
 static void __exit exit_gfs2_fs(void)
 {
+	unregister_shrinker(&qd_shrinker);
 	gfs2_glock_exit();
 	gfs2_unregister_debugfs();
 	unregister_filesystem(&gfs2_fs_type);

fs/gfs2/ops_address.c

@@ -442,6 +442,7 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
 	 */
 	if (unlikely(page->index)) {
 		zero_user(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
 		return 0;
 	}
 

fs/gfs2/ops_fstype.c

@@ -63,7 +63,6 @@ static void gfs2_tune_init(struct gfs2_tune *gt)
 	gt->gt_quota_warn_period = 10;
 	gt->gt_quota_scale_num = 1;
 	gt->gt_quota_scale_den = 1;
-	gt->gt_quota_cache_secs = 300;
 	gt->gt_quota_quantum = 60;
 	gt->gt_new_files_jdata = 0;
 	gt->gt_max_readahead = 1 << 18;