jbd2: Mark jbd2 slabs as SLAB_TEMPORARY

This patch marks slab allocations by jbd2 as short-lived in support of
Mel Gorman's "Group short-lived and reclaimable kernel allocations"
patch.  (Ported from similar changes made to fs/jbd/journal.c and
fs/jbd/revoke.c in Mel's patch.)

Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/jbd2/journal.c

@@ -1973,7 +1973,7 @@ static int journal_init_jbd2_journal_head_cache(void)
 	jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
 				sizeof(struct journal_head),
 				0,		/* offset */
-				0,		/* flags */
+				SLAB_TEMPORARY,	/* flags */
 				NULL);		/* ctor */
 	retval = 0;
 	if (jbd2_journal_head_cache == 0) {
@@ -2269,7 +2269,7 @@ static int __init journal_init_handle_cache(void)
 	jbd2_handle_cache = kmem_cache_create("jbd2_journal_handle",
 				sizeof(handle_t),
 				0,		/* offset */
-				0,		/* flags */
+				SLAB_TEMPORARY,	/* flags */
 				NULL);		/* ctor */
 	if (jbd2_handle_cache == NULL) {
 		printk(KERN_EMERG "JBD: failed to create handle cache\n");

fs/jbd2/revoke.c

@@ -171,13 +171,15 @@ int __init jbd2_journal_init_revoke_caches(void)
 {
 	jbd2_revoke_record_cache = kmem_cache_create("jbd2_revoke_record",
 					   sizeof(struct jbd2_revoke_record_s),
-					   0, SLAB_HWCACHE_ALIGN, NULL);
+					   0,
+					   SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
+					   NULL);
 	if (jbd2_revoke_record_cache == 0)
 		return -ENOMEM;
 
 	jbd2_revoke_table_cache = kmem_cache_create("jbd2_revoke_table",
 					   sizeof(struct jbd2_revoke_table_s),
-					   0, 0, NULL);
+					   0, SLAB_TEMPORARY, NULL);
 	if (jbd2_revoke_table_cache == 0) {
 		kmem_cache_destroy(jbd2_revoke_record_cache);
 		jbd2_revoke_record_cache = NULL;