[PATCH] nilfs2: cleanup multi kmem_cache_{create,destroy} code

From: Li Hong
Date: Mon Apr 05 2010 - 12:54:11 EST


This cleanup patch gives several improvements:

- Moving all kmem_cache_{create_destroy} calls into one place, which removes
some small function calls, cleans up error check code and clarify the logic.

- Mark all initial code in __init section.

- Remove some very obvious comments.

- Adjust some declarations.

- Fix some space-tab issues.

Signed-off-by: Li Hong <lihong.hi@xxxxxxxxx>
---
fs/nilfs2/btree.c | 40 ----------------
fs/nilfs2/btree.h | 23 ++++++++-
fs/nilfs2/segbuf.c | 25 ----------
fs/nilfs2/segbuf.h | 1 +
fs/nilfs2/segment.c | 36 --------------
fs/nilfs2/segment.h | 2 +
fs/nilfs2/super.c | 128 ++++++++++++++++++++++++++------------------------
7 files changed, 90 insertions(+), 165 deletions(-)

diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index dcd4e1c..b27a342 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -31,46 +31,6 @@
#include "alloc.h"
#include "dat.h"

-/**
- * struct nilfs_btree_path - A path on which B-tree operations are executed
- * @bp_bh: buffer head of node block
- * @bp_sib_bh: buffer head of sibling node block
- * @bp_index: index of child node
- * @bp_oldreq: ptr end request for old ptr
- * @bp_newreq: ptr alloc request for new ptr
- * @bp_op: rebalance operation
- */
-struct nilfs_btree_path {
- struct buffer_head *bp_bh;
- struct buffer_head *bp_sib_bh;
- int bp_index;
- union nilfs_bmap_ptr_req bp_oldreq;
- union nilfs_bmap_ptr_req bp_newreq;
- struct nilfs_btnode_chkey_ctxt bp_ctxt;
- void (*bp_op)(struct nilfs_btree *, struct nilfs_btree_path *,
- int, __u64 *, __u64 *);
-};
-
-/*
- * B-tree path operations
- */
-
-static struct kmem_cache *nilfs_btree_path_cache;
-
-int __init nilfs_btree_path_cache_init(void)
-{
- nilfs_btree_path_cache =
- kmem_cache_create("nilfs2_btree_path_cache",
- sizeof(struct nilfs_btree_path) *
- NILFS_BTREE_LEVEL_MAX, 0, 0, NULL);
- return (nilfs_btree_path_cache != NULL) ? 0 : -ENOMEM;
-}
-
-void nilfs_btree_path_cache_destroy(void)
-{
- kmem_cache_destroy(nilfs_btree_path_cache);
-}
-
static struct nilfs_btree_path *nilfs_btree_alloc_path(void)
{
struct nilfs_btree_path *path;
diff --git a/fs/nilfs2/btree.h b/fs/nilfs2/btree.h
index 4b82d84..af638d5 100644
--- a/fs/nilfs2/btree.h
+++ b/fs/nilfs2/btree.h
@@ -30,9 +30,6 @@
#include "btnode.h"
#include "bmap.h"

-struct nilfs_btree;
-struct nilfs_btree_path;
-
/**
* struct nilfs_btree - B-tree structure
* @bt_bmap: bmap base structure
@@ -41,6 +38,25 @@ struct nilfs_btree {
struct nilfs_bmap bt_bmap;
};

+/**
+ * struct nilfs_btree_path - A path on which B-tree operations are executed
+ * @bp_bh: buffer head of node block
+ * @bp_sib_bh: buffer head of sibling node block
+ * @bp_index: index of child node
+ * @bp_oldreq: ptr end request for old ptr
+ * @bp_newreq: ptr alloc request for new ptr
+ * @bp_op: rebalance operation
+ */
+struct nilfs_btree_path {
+ struct buffer_head *bp_bh;
+ struct buffer_head *bp_sib_bh;
+ int bp_index;
+ union nilfs_bmap_ptr_req bp_oldreq;
+ union nilfs_bmap_ptr_req bp_newreq;
+ struct nilfs_btnode_chkey_ctxt bp_ctxt;
+ void (*bp_op)(struct nilfs_btree *, struct nilfs_btree_path *,
+ int, __u64 *, __u64 *);
+};

#define NILFS_BTREE_ROOT_SIZE NILFS_BMAP_SIZE
#define NILFS_BTREE_ROOT_NCHILDREN_MAX \
@@ -57,6 +73,7 @@ struct nilfs_btree {
#define NILFS_BTREE_KEY_MIN ((__u64)0)
#define NILFS_BTREE_KEY_MAX (~(__u64)0)

+extern struct kmem_cache *nilfs_btree_path_cache;

int nilfs_btree_path_cache_init(void);
void nilfs_btree_path_cache_destroy(void);
diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c
index 6129a43..4a4b433 100644
--- a/fs/nilfs2/segbuf.c
+++ b/fs/nilfs2/segbuf.c
@@ -39,35 +39,10 @@ struct nilfs_write_info {
sector_t blocknr;
};

-
static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
struct the_nilfs *nilfs);
static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);

-
-static struct kmem_cache *nilfs_segbuf_cachep;
-
-static void nilfs_segbuf_init_once(void *obj)
-{
- memset(obj, 0, sizeof(struct nilfs_segment_buffer));
-}
-
-int __init nilfs_init_segbuf_cache(void)
-{
- nilfs_segbuf_cachep =
- kmem_cache_create("nilfs2_segbuf_cache",
- sizeof(struct nilfs_segment_buffer),
- 0, SLAB_RECLAIM_ACCOUNT,
- nilfs_segbuf_init_once);
-
- return (nilfs_segbuf_cachep == NULL) ? -ENOMEM : 0;
-}
-
-void nilfs_destroy_segbuf_cache(void)
-{
- kmem_cache_destroy(nilfs_segbuf_cachep);
-}
-
struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
{
struct nilfs_segment_buffer *segbuf;
diff --git a/fs/nilfs2/segbuf.h b/fs/nilfs2/segbuf.h
index 94dfd35..cad9c7c 100644
--- a/fs/nilfs2/segbuf.h
+++ b/fs/nilfs2/segbuf.h
@@ -121,6 +121,7 @@ struct nilfs_segment_buffer {
b_assoc_buffers))
#define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head)

+extern struct kmem_cache *nilfs_segbuf_cachep;

int __init nilfs_init_segbuf_cache(void);
void nilfs_destroy_segbuf_cache(void);
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index c161d89..1138713 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -115,42 +115,6 @@ static void nilfs_dispose_list(struct nilfs_sb_info *, struct list_head *,
#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a)
#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a)

-/*
- * Transaction
- */
-static struct kmem_cache *nilfs_transaction_cachep;
-
-/**
- * nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
- *
- * nilfs_init_transaction_cache() creates a slab cache for the struct
- * nilfs_transaction_info.
- *
- * Return Value: On success, it returns 0. On error, one of the following
- * negative error code is returned.
- *
- * %-ENOMEM - Insufficient memory available.
- */
-int nilfs_init_transaction_cache(void)
-{
- nilfs_transaction_cachep =
- kmem_cache_create("nilfs2_transaction_cache",
- sizeof(struct nilfs_transaction_info),
- 0, SLAB_RECLAIM_ACCOUNT, NULL);
- return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
-}
-
-/**
- * nilfs_destroy_transaction_cache - destroy the cache for transaction info
- *
- * nilfs_destroy_transaction_cache() frees the slab cache for the struct
- * nilfs_transaction_info.
- */
-void nilfs_destroy_transaction_cache(void)
-{
- kmem_cache_destroy(nilfs_transaction_cachep);
-}
-
static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
{
struct nilfs_transaction_info *cur_ti = current->journal_info;
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h
index 82dfd6a..2de218b 100644
--- a/fs/nilfs2/segment.h
+++ b/fs/nilfs2/segment.h
@@ -219,6 +219,8 @@ enum {
*/
#define NILFS_SC_DEFAULT_WATERMARK 3600

+/* super.c */
+extern struct kmem_cache *nilfs_transaction_cachep;

/* segment.c */
extern int nilfs_init_transaction_cache(void);
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index aa1ad6c..2e767bc 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -67,6 +67,11 @@ MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
"(NILFS)");
MODULE_LICENSE("GPL");

+struct kmem_cache *nilfs_inode_cachep;
+struct kmem_cache *nilfs_transaction_cachep;
+struct kmem_cache *nilfs_segbuf_cachep;
+struct kmem_cache *nilfs_btree_path_cache;
+
static int nilfs_remount(struct super_block *sb, int *flags, char *data);

/**
@@ -129,7 +134,6 @@ void nilfs_warning(struct super_block *sb, const char *function,
va_end(args);
}

-static struct kmem_cache *nilfs_inode_cachep;

struct inode *nilfs_alloc_inode_common(struct the_nilfs *nilfs)
{
@@ -155,34 +159,6 @@ void nilfs_destroy_inode(struct inode *inode)
kmem_cache_free(nilfs_inode_cachep, NILFS_I(inode));
}

-static void init_once(void *obj)
-{
- struct nilfs_inode_info *ii = obj;
-
- INIT_LIST_HEAD(&ii->i_dirty);
-#ifdef CONFIG_NILFS_XATTR
- init_rwsem(&ii->xattr_sem);
-#endif
- nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
- ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
- inode_init_once(&ii->vfs_inode);
-}
-
-static int nilfs_init_inode_cache(void)
-{
- nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
- sizeof(struct nilfs_inode_info),
- 0, SLAB_RECLAIM_ACCOUNT,
- init_once);
-
- return (nilfs_inode_cachep == NULL) ? -ENOMEM : 0;
-}
-
-static inline void nilfs_destroy_inode_cache(void)
-{
- kmem_cache_destroy(nilfs_inode_cachep);
-}
-
static void nilfs_clear_inode(struct inode *inode)
{
struct nilfs_inode_info *ii = NILFS_I(inode);
@@ -1138,54 +1114,84 @@ struct file_system_type nilfs_fs_type = {
.fs_flags = FS_REQUIRES_DEV,
};

-static int __init init_nilfs_fs(void)
+static void nilfs_inode_init_once(void *obj)
{
- int err;
-
- err = nilfs_init_inode_cache();
- if (err)
- goto failed;
+ struct nilfs_inode_info *ii = obj;

- err = nilfs_init_transaction_cache();
- if (err)
- goto failed_inode_cache;
+ INIT_LIST_HEAD(&ii->i_dirty);
+#ifdef CONFIG_NILFS_XATTR
+ init_rwsem(&ii->xattr_sem);
+#endif
+ nilfs_btnode_cache_init_once(&ii->i_btnode_cache);
+ ii->i_bmap = (struct nilfs_bmap *)&ii->i_bmap_union;
+ inode_init_once(&ii->vfs_inode);
+}

- err = nilfs_init_segbuf_cache();
- if (err)
- goto failed_transaction_cache;
+static void nilfs_segbuf_init_once(void *obj)
+{
+ memset(obj, 0, sizeof(struct nilfs_segment_buffer));
+}

- err = nilfs_btree_path_cache_init();
- if (err)
- goto failed_segbuf_cache;
+static void nilfs_destroy_cachep(void)
+{
+ if (nilfs_inode_cachep)
+ kmem_cache_destroy(nilfs_inode_cachep);
+ if (nilfs_transaction_cachep)
+ kmem_cache_destroy(nilfs_transaction_cachep);
+ if (nilfs_segbuf_cachep)
+ kmem_cache_destroy(nilfs_segbuf_cachep);
+ if (nilfs_btree_path_cache)
+ kmem_cache_destroy(nilfs_btree_path_cache);
+}

- err = register_filesystem(&nilfs_fs_type);
- if (err)
- goto failed_btree_path_cache;
+static int __init nilfs_init_cachep(void)
+{
+ nilfs_inode_cachep = kmem_cache_create("nilfs2_inode_cache",
+ sizeof(struct nilfs_inode_info), 0,
+ SLAB_RECLAIM_ACCOUNT, nilfs_inode_init_once);
+ if (!nilfs_inode_cachep)
+ goto fail;
+
+ nilfs_transaction_cachep = kmem_cache_create("nilfs2_transaction_cache",
+ sizeof(struct nilfs_transaction_info), 0,
+ SLAB_RECLAIM_ACCOUNT, NULL);
+ if (!nilfs_transaction_cachep)
+ goto fail;
+
+ nilfs_segbuf_cachep = kmem_cache_create("nilfs2_segbuf_cache",
+ sizeof(struct nilfs_segment_buffer), 0,
+ SLAB_RECLAIM_ACCOUNT, nilfs_segbuf_init_once);
+ if (!nilfs_segbuf_cachep)
+ goto fail;
+
+ nilfs_btree_path_cache = kmem_cache_create("nilfs2_btree_path_cache",
+ sizeof(struct nilfs_btree_path) * NILFS_BTREE_LEVEL_MAX,
+ 0, 0, NULL);
+ if (!nilfs_btree_path_cache)
+ goto fail;

return 0;

- failed_btree_path_cache:
- nilfs_btree_path_cache_destroy();
-
- failed_segbuf_cache:
- nilfs_destroy_segbuf_cache();
+fail:
+ nilfs_destroy_cachep();
+ return -ENOMEM;
+}

- failed_transaction_cache:
- nilfs_destroy_transaction_cache();
+static int __init init_nilfs_fs(void)
+{
+ int err;

- failed_inode_cache:
- nilfs_destroy_inode_cache();
+ err = nilfs_init_cachep();
+ if (err)
+ return err;

- failed:
+ err = register_filesystem(&nilfs_fs_type);
return err;
}

static void __exit exit_nilfs_fs(void)
{
- nilfs_destroy_segbuf_cache();
- nilfs_destroy_transaction_cache();
- nilfs_destroy_inode_cache();
- nilfs_btree_path_cache_destroy();
+ nilfs_destroy_cachep();
unregister_filesystem(&nilfs_fs_type);
}

--
1.6.3.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/