JBD2: jbd2 slab allocation cleanups

JBD2: Replace slab allocations with page allocations

JBD2 allocate memory for committed_data and frozen_data from slab. However
JBD2 should not pass slab pages down to the block layer. Use page allocator
pages instead. This will also prepare JBD for the large blocksize patchset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>

fs/jbd2/commit.c

@@ -384,7 +384,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 			struct buffer_head *bh = jh2bh(jh);
 
 			jbd_lock_bh_state(bh);
-			jbd2_slab_free(jh->b_committed_data, bh->b_size);
+			jbd2_free(jh->b_committed_data, bh->b_size);
 			jh->b_committed_data = NULL;
 			jbd_unlock_bh_state(bh);
 		}
@@ -801,14 +801,14 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		 * Otherwise, we can just throw away the frozen data now.
 		 */
 		if (jh->b_committed_data) {
-			jbd2_slab_free(jh->b_committed_data, bh->b_size);
+			jbd2_free(jh->b_committed_data, bh->b_size);
 			jh->b_committed_data = NULL;
 			if (jh->b_frozen_data) {
 				jh->b_committed_data = jh->b_frozen_data;
 				jh->b_frozen_data = NULL;
 			}
 		} else if (jh->b_frozen_data) {
-			jbd2_slab_free(jh->b_frozen_data, bh->b_size);
+			jbd2_free(jh->b_frozen_data, bh->b_size);
 			jh->b_frozen_data = NULL;
 		}
 

fs/jbd2/journal.c

@@ -84,7 +84,6 @@ EXPORT_SYMBOL(jbd2_journal_force_commit);
 
 static int journal_convert_superblock_v1(journal_t *, journal_superblock_t *);
 static void __journal_abort_soft (journal_t *journal, int errno);
-static int jbd2_journal_create_jbd_slab(size_t slab_size);
 
 /*
  * Helper function used to manage commit timeouts
@@ -335,10 +334,10 @@ int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 		char *tmp;
 
 		jbd_unlock_bh_state(bh_in);
-		tmp = jbd2_slab_alloc(bh_in->b_size, GFP_NOFS);
+		tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
 		jbd_lock_bh_state(bh_in);
 		if (jh_in->b_frozen_data) {
-			jbd2_slab_free(tmp, bh_in->b_size);
+			jbd2_free(tmp, bh_in->b_size);
 			goto repeat;
 		}
 
@@ -1096,13 +1095,6 @@ int jbd2_journal_load(journal_t *journal)
 		}
 	}
 
-	/*
-	 * Create a slab for this blocksize
-	 */
-	err = jbd2_journal_create_jbd_slab(be32_to_cpu(sb->s_blocksize));
-	if (err)
-		return err;
-
 	/* Let the recovery code check whether it needs to recover any
 	 * data from the journal. */
 	if (jbd2_journal_recover(journal))
@@ -1635,77 +1627,6 @@ void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry)
 	return kmalloc(size, flags | (retry ? __GFP_NOFAIL : 0));
 }
 
-/*
- * jbd slab management: create 1k, 2k, 4k, 8k slabs as needed
- * and allocate frozen and commit buffers from these slabs.
- *
- * Reason for doing this is to avoid, SLAB_DEBUG - since it could
- * cause bh to cross page boundary.
- */
-
-#define JBD_MAX_SLABS 5
-#define JBD_SLAB_INDEX(size)  (size >> 11)
-
-static struct kmem_cache *jbd_slab[JBD_MAX_SLABS];
-static const char *jbd_slab_names[JBD_MAX_SLABS] = {
-	"jbd2_1k", "jbd2_2k", "jbd2_4k", NULL, "jbd2_8k"
-};
-
-static void jbd2_journal_destroy_jbd_slabs(void)
-{
-	int i;
-
-	for (i = 0; i < JBD_MAX_SLABS; i++) {
-		if (jbd_slab[i])
-			kmem_cache_destroy(jbd_slab[i]);
-		jbd_slab[i] = NULL;
-	}
-}
-
-static int jbd2_journal_create_jbd_slab(size_t slab_size)
-{
-	int i = JBD_SLAB_INDEX(slab_size);
-
-	BUG_ON(i >= JBD_MAX_SLABS);
-
-	/*
-	 * Check if we already have a slab created for this size
-	 */
-	if (jbd_slab[i])
-		return 0;
-
-	/*
-	 * Create a slab and force alignment to be same as slabsize -
-	 * this will make sure that allocations won't cross the page
-	 * boundary.
-	 */
-	jbd_slab[i] = kmem_cache_create(jbd_slab_names[i],
-				slab_size, slab_size, 0, NULL);
-	if (!jbd_slab[i]) {
-		printk(KERN_EMERG "JBD: no memory for jbd_slab cache\n");
-		return -ENOMEM;
-	}
-	return 0;
-}
-
-void * jbd2_slab_alloc(size_t size, gfp_t flags)
-{
-	int idx;
-
-	idx = JBD_SLAB_INDEX(size);
-	BUG_ON(jbd_slab[idx] == NULL);
-	return kmem_cache_alloc(jbd_slab[idx], flags | __GFP_NOFAIL);
-}
-
-void jbd2_slab_free(void *ptr,  size_t size)
-{
-	int idx;
-
-	idx = JBD_SLAB_INDEX(size);
-	BUG_ON(jbd_slab[idx] == NULL);
-	kmem_cache_free(jbd_slab[idx], ptr);
-}
-
 /*
  * Journal_head storage management
  */
@@ -1893,13 +1814,13 @@ static void __journal_remove_journal_head(struct buffer_head *bh)
 				printk(KERN_WARNING "%s: freeing "
 						"b_frozen_data\n",
 						__FUNCTION__);
-				jbd2_slab_free(jh->b_frozen_data, bh->b_size);
+				jbd2_free(jh->b_frozen_data, bh->b_size);
 			}
 			if (jh->b_committed_data) {
 				printk(KERN_WARNING "%s: freeing "
 						"b_committed_data\n",
 						__FUNCTION__);
-				jbd2_slab_free(jh->b_committed_data, bh->b_size);
+				jbd2_free(jh->b_committed_data, bh->b_size);
 			}
 			bh->b_private = NULL;
 			jh->b_bh = NULL;	/* debug, really */
@@ -2040,7 +1961,6 @@ static void jbd2_journal_destroy_caches(void)
 	jbd2_journal_destroy_revoke_caches();
 	jbd2_journal_destroy_jbd2_journal_head_cache();
 	jbd2_journal_destroy_handle_cache();
-	jbd2_journal_destroy_jbd_slabs();
 }
 
 static int __init journal_init(void)

fs/jbd2/transaction.c

@@ -236,7 +236,7 @@ static int start_this_handle(journal_t *journal, handle_t *handle)
 /* Allocate a new handle.  This should probably be in a slab... */
 static handle_t *new_handle(int nblocks)
 {
-	handle_t *handle = jbd_alloc_handle(GFP_NOFS);
+	handle_t *handle = jbd2_alloc_handle(GFP_NOFS);
 	if (!handle)
 		return NULL;
 	memset(handle, 0, sizeof(*handle));
@@ -282,7 +282,7 @@ handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
 
 	err = start_this_handle(journal, handle);
 	if (err < 0) {
-		jbd_free_handle(handle);
+		jbd2_free_handle(handle);
 		current->journal_info = NULL;
 		handle = ERR_PTR(err);
 	}
@@ -668,7 +668,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh,
 				JBUFFER_TRACE(jh, "allocate memory for buffer");
 				jbd_unlock_bh_state(bh);
 				frozen_buffer =
-					jbd2_slab_alloc(jh2bh(jh)->b_size,
+					jbd2_alloc(jh2bh(jh)->b_size,
 							 GFP_NOFS);
 				if (!frozen_buffer) {
 					printk(KERN_EMERG
@@ -728,7 +728,7 @@ do_get_write_access(handle_t *handle, struct journal_head *jh,
 
 out:
 	if (unlikely(frozen_buffer))	/* It's usually NULL */
-		jbd2_slab_free(frozen_buffer, bh->b_size);
+		jbd2_free(frozen_buffer, bh->b_size);
 
 	JBUFFER_TRACE(jh, "exit");
 	return error;
@@ -881,7 +881,7 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
 
 repeat:
 	if (!jh->b_committed_data) {
-		committed_data = jbd2_slab_alloc(jh2bh(jh)->b_size, GFP_NOFS);
+		committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS);
 		if (!committed_data) {
 			printk(KERN_EMERG "%s: No memory for committed data\n",
 				__FUNCTION__);
@@ -908,7 +908,7 @@ int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
 out:
 	jbd2_journal_put_journal_head(jh);
 	if (unlikely(committed_data))
-		jbd2_slab_free(committed_data, bh->b_size);
+		jbd2_free(committed_data, bh->b_size);
 	return err;
 }
 
@@ -1411,7 +1411,7 @@ int jbd2_journal_stop(handle_t *handle)
 		spin_unlock(&journal->j_state_lock);
 	}
 
-	jbd_free_handle(handle);
+	jbd2_free_handle(handle);
 	return err;
 }
 

include/linux/jbd2.h

@@ -72,14 +72,22 @@ extern u8 jbd2_journal_enable_debug;
 #endif
 
 extern void * __jbd2_kmalloc (const char *where, size_t size, gfp_t flags, int retry);
-extern void * jbd2_slab_alloc(size_t size, gfp_t flags);
-extern void jbd2_slab_free(void *ptr, size_t size);
-
 #define jbd_kmalloc(size, flags) \
 	__jbd2_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
 #define jbd_rep_kmalloc(size, flags) \
 	__jbd2_kmalloc(__FUNCTION__, (size), (flags), 1)
 
+
+static inline void *jbd2_alloc(size_t size, gfp_t flags)
+{
+	return (void *)__get_free_pages(flags, get_order(size));
+}
+
+static inline void jbd2_free(void *ptr, size_t size)
+{
+	free_pages((unsigned long)ptr, get_order(size));
+};
+
 #define JBD2_MIN_JOURNAL_BLOCKS 1024
 
 #ifdef __KERNEL__
@@ -959,12 +967,12 @@ void jbd2_journal_put_journal_head(struct journal_head *jh);
  */
 extern struct kmem_cache *jbd2_handle_cache;
 
-static inline handle_t *jbd_alloc_handle(gfp_t gfp_flags)
+static inline handle_t *jbd2_alloc_handle(gfp_t gfp_flags)
 {
 	return kmem_cache_alloc(jbd2_handle_cache, gfp_flags);
 }
 
-static inline void jbd_free_handle(handle_t *handle)
+static inline void jbd2_free_handle(handle_t *handle)
 {
 	kmem_cache_free(jbd2_handle_cache, handle);
 }