[PATCH v3 1/2] xfs: add xfs_log_vec_cache for separate xfs_log_vec/xfs_log_iovec

[alexjlzheng@gmail.com]

From: Jinliang Zheng <alexjlzheng@tencent.com>

This patch prepares for the next patch that separates xfs_log_iovec
from the xfs_log_vec/xfs_log_iovec combination.

Because xfs_log_vec itself is a very small object, there is no need
to fallback to vmalloc(). Use kmalloc() to allocate memory for
xfs_log_vec and use kmem_cache to speed it up.

Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
---
 fs/xfs/xfs_log.c   | 1 +
 fs/xfs/xfs_log.h   | 2 ++
 fs/xfs/xfs_super.c | 9 +++++++++
 3 files changed, 12 insertions(+)

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 416c15494983..49e676061f2f 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -21,6 +21,7 @@
 #include "xfs_sb.h"
 #include "xfs_health.h"
 
+struct kmem_cache	*xfs_log_vec_cache;
 struct kmem_cache	*xfs_log_ticket_cache;
 
 /* Local miscellaneous function prototypes */
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index d69acf881153..9cc10acf7bcd 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -20,6 +20,8 @@ struct xfs_log_vec {
 	int			lv_size;	/* size of allocated lv */
 };
 
+extern struct kmem_cache *xfs_log_vec_cache;
+
 #define XFS_LOG_VEC_ORDERED	(-1)
 
 /*
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 27e9f749c4c7..7e94f9439a8f 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -2222,8 +2222,16 @@ xfs_init_caches(void)
 	if (!xfs_parent_args_cache)
 		goto out_destroy_xmi_cache;
 
+	xfs_log_vec_cache = kmem_cache_create("xfs_log_vec",
+						sizeof(struct xfs_log_vec),
+						0, 0, NULL);
+	if (!xfs_log_vec_cache)
+		goto out_destroy_args_cache;
+
 	return 0;
 
+ out_destroy_args_cache:
+	kmem_cache_destroy(xfs_parent_args_cache);
  out_destroy_xmi_cache:
 	kmem_cache_destroy(xfs_xmi_cache);
  out_destroy_xmd_cache:
@@ -2286,6 +2294,7 @@ xfs_destroy_caches(void)
 	 * destroy caches.
 	 */
 	rcu_barrier();
+	kmem_cache_destroy(xfs_log_vec_cache);
 	kmem_cache_destroy(xfs_parent_args_cache);
 	kmem_cache_destroy(xfs_xmd_cache);
 	kmem_cache_destroy(xfs_xmi_cache);
-- 
2.41.1